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关于杜邦分析法的外文翻译

外文资料及中文译文作者姓名***专业财务管理指导教师姓名***专业技术职务副教授外文资料FIVE WAYS TO IMPROVE RETURN ON EQUITYThe Du Pont Model: A Brief HistoryThe use of financial ratios by financial analysts, lenders, academic researchers, and small business owners has been widely acknowleged in the literature. (See, for example, Osteryoung & Constand (1992), Devine & Seaton (1995), or Burson (1998) The concepts of Return on Assets (ROA hereafter) and Return on Equity (ROEhereafter) are important for understanding the profitability of a business enterprise. Specifically, a “return on” ratio illustrates the relationship between profits and the investment needed to generate those profits. However, these concepts are often “too far removed from normal activities” to be easily understood and useful to many managers or small business owners. (Slater and Olson, 1996)In 1918, four years after he was hired by the Du Pont Corporation to work in its treasury department, electrical engineer F. Donaldson Brown was given the task of untangling the finances of a company of which Du Pont had just purchased 23 percent of its stock. (This company was General Motors!) Brown recognized a mathematical relationship that existed between two commonly computed ratios, namely net profit margin (obviously a profitability measure) and total asset turnover (an efficiency measure), and ROA. The product of the net profit margin and total asset turnover equals ROA, and this was the original Du Pont model, as illustrated in Equation 1 below.Eq. 1: (net income / sales) x (sales / total assets) = (net income / total assets) i.e. ROAAt this point in time maximizing ROA was a common corporate goal and the realization that ROA was impacted by both profitability and efficiency led to the development of a system of planning and control for all operating decisions within a firm. This became the dominant form of financial analysis until the 1970s. (Blumenthal, 1998)In the 1970s the generally accepted goal of financial management became “maximizing the wealth of the firm’s owners” (Gitman, 1998) and focus shifted from ROA to ROE. This led to the first major modification of the original Du Pontmodel. In addition to profitability and efficiency, the way in which a firm financed its activities, i.e. its use of “leverage” became a third area of attention for financial managers. The new ratio of interest was called the equity multiplier, which is (total assets / equity). The modified Du Pont model is shown in Equations 1 and 2 below.Eq. 2: ROA x (total assets / equity) = ROEEq. 3: (net income / sales) x (sales / total assets) x (total assets / equity) = ROE The modified Du Pont model became a standard in all financial management textbooks and a staple of introductory and advanced courses alike as students read statements such as: “Ultimately, the most important, or“bottom line” accounting ratio is the ratio of net income to common equity (ROE).” (Brigham and Houston, 2001)The modified model was a powerful tool to illustrate the interconnectedness of a firm’s income statement and its balance sheet, and to develop straight-forward strategies for improving the firm’s ROE.More recently, Hawawini and Viallet (1999) offered yet another modification to the Du Pontmodel. This modification resulted in five different ratios that combine to form ROE. In their modification they acknowlege that thefinancial statements firms prepare for their annualreports (which are of most importance to creditorsand tax collectors) are not always useful tomanagers making operating and financialdecisions. (Brigham and Houston, p. 52) T heyrestructured the traditional balance sheet into a“managerial balance sheet” which is “a moreappropriate tool for assessing the contribution ofoperating decisions to the firm’s financialperformance.” (Hawawini and Viallet, p.68)This restructured balanc e sheet uses the conceptof “invested capital” in place of total assets, andthe concept of “capital employed” in place oftotal liabilities and owner’sequity found on thetraditional balance sheet. The primary differenceis in the treatment of the short-ter m “workingcapital” accounts. The managerial balance sheet uses a net figure called “working capital requirement” (determined as: [accounts receivable + inventories + prepaid expenses] – [accounts payable + accrued expenses]) as a part of invested capital. These accounts then individually drop out of the managerial balance sheet. A more detailed explanation of the managerial balance sheet is beyond the scope of this paper, but will be partially illustrated in an example. The “really” modified Du Pont mode l is shown below in Equation 4.Eq. 4: (EBIT / sales) x (sales / invested capital) x (EBT / EBIT) x (invested capital / equity) x (EAT / EBT) = ROE(Where: invested capital = cash + working capital requirement + net fixed assets) This “really” modified model still maintains the importance of the impact of operating decisions (i.e. profitability and efficiency) and financing decisions (leverage) upon ROE, but uses a total of five ratios to uncover what drives ROE and give insight to how to improve this important ratio.The firm’s operating decisions are those that involve the acquisition and disposal of fixed assets and the management of the firm’s operating assets (mostly inventories and accounts receivable) and operating liabilities (accountspayable and accruals). These are captured in thefirst two ratios of the “really” modified Du Pontmodel. These are:1. operating profit margin: (Earnings Before Interest & Taxes or EBIT / sales)2. capital turnover: (sales / invested capital)The firm’s financing decisions are those that determine the mix of debt and equity used to fund the firm’s operating decisions. These are captured in the third and fourth ratios of the “really” modified model. These are:3. financial cost ratio: (Earnings Before Taxes or EBT / EBIT)4. financial structure ratio: (invested capital / equity)The final determinant of a firm’s ROE is the incidence of business taxation. The higher the taxrate applied to a firm’s EBT, the lower its ROE. This is cap tured in the fifth ratio ofthe “really”modified model.5. tax effect ratio: (Earnings After Taxes or EAT / EBT)The relationship that ties these five ratios together is that ROE is equal to their combined product. (See Equation 4.)Example of A pplying the “Really” Modified Du Pont ModelTo illustrate how the model works, consider the income statement and balance sheet for the fictitious small firm of Herrera & Company, LLC.Income StatementNet Sales …………………………………………………….. $766,990C ost of Goods Sold ………………………………………….. (560,000) Selling, General, & Administrative Expenses ………………. (143,342) Depreciation Expense ……………………………………….. (24,000) Earnings Before Interest & Taxes …………………………… $ 39,648Interest Expense ……………………………………………... (12,447) Earnings Before Taxes ………………………………………. $ 27,201Taxes ………………………………………………………… (8,000) Earnings After Taxes (net profit) ……………………………. $ 19,201Balance SheetCash ……………………….$ 40,000 Notes Payable ………………… $ 58,000 Pre-paid Expenses ………... 12,000 Accounts Payable …………….. 205,000 Accounts Receivable ……… 185,000 Accrued Expenses ……………. 46,000 Inventory ………………….. 200,000 Current Liabilities ……………. $309,000 Current Assets ……………. $437,000 Long-Term DebtL and/Buildings …………… 160,000 Mortgage ……………………. 104,300Equipment ………………… 89,000 8-Year Note ………………… 63,000Less: Acc. Depreciation …... (24,000) Owner’s Equity ……………….. 185,700Net Fixed Assets ………….. $225,000 Total Liabilities & Equity …….. $662,000 Total Assets ………………. $662,000Computation of ROE1. Operating Profit Margin = $39,648 / $766,990 = .05172. Capital Turnover = $766,990 / $411,000* = 1.86623. Financial Cost Ratio = $27,201 / $39,648 = .68614. Financial Structure Ratio = $411,000 / $185,700 = 2.21325. Tax Effect Ratio = $19,201 / $27,201 = .7059ROE = .0517 x 1.8662 x .6861 x 2.2132 x .7059 = .1034** or 10.34%* Invested Capital = Cash ($40,000) + Working Capital Requirement [$185,000 + $200,000 + $12,000] –[$205,000 + $46,000] (or $146,000) + Net Fixed Assets ($225,000) = $411,000** Note that this is the same as conventional computation of ROE: $19,201 / $185,700 = .1034Conclusions & ImplicationsThe “really” modified Du Pont model of ratio analysis can demystify relatively complex financial analysis and put strategic financial planning at the fingertips of any small business owner or manager who takes the (relatively little) time needed to understand it. Each operating and financial decision can be made within a framework of how that decision will impact ROE. Easily set up on a computer model (such as a spreadsheet), one can see how decisions “flow through” to the bottom line, which facilitates coordinated financial planning. (Harrington & Wilson,1986).In its simplest form, we can say that to improve ROE the only choices one has are to increase operating profits, become more efficient in using existing assets to generate sales, recapitalize to make better use of debt and/or better control the cost of borrowing, or find ways to reduce the tax liability of the firm. Each of these choices leads to a different financial strategy.For example, to increase operating profits one must either increase sales (in a higher proportionthan the cost of generating those sales) or reduce expenses. Since it is generally more difficult toincrease sales than it is to reduce expenses, a small business owner can try to lower expenses by determining: 1) if a new supplier might offer equivalent goods at a lower cost, or 2) if a website might be a viable alternative to a catalog, or 3) can some tasks currently being done by outsiders be done in-house. In each case net income will rise without any increase in sales and ROE will rise as well. Alternatively, to become more efficient, one must either increase sales with the same level of assets or produce the same level of sales with less assets. A small business owner might then try to determine: 1) if it is feasible to expand store hours by staying open later or on weekends, or 2) if a less expensive piece of equipment is available that could replace an existing (more expensive) piece of equipment, or 3) if there is a more practical way to produce and/or deliver goods or services than is presently being used.Further, small business owners can determine if they are using debt wisely. Refinancing an existing loan at a cheaper rate will reduce interest expenses and, thus, increase ROE. Exercising some of an unused line of credit can increase the financial structure ratio with a corresponding increase in ROE. And, taking advantage of tax incentives that are often offered by federal, state,and local taxing authorities can increase the tax effect ratio, again with a commensurate increase in ROE.In conclusion, ROE is the most compre-hensive measure of profitability of a firm. It considers the operating and investing decisions made as well as the financing andtax-related decisions. The “really” modified Du Pont model dissects ROE into five easily computed ratios that can be examined for potential strategies for improvement. It should be a tool that all business owners, managers, and consultants have at their disposal when evaluating a firm and making recommendations for improvement.中文译文真实修改的杜邦分析：五种方式改善股东权益回报率杜邦模型：简史运用财务比率进行分析已经被财务分析家，贷款人，学术研究人员和小企业主在文献资料里广泛运用。

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土木工程外文文献及翻译

本科毕业设计外文文献及译文文献、资料题目：Designing Against Fire Of Building 文献、资料来源：国道数据库文献、资料发表（出版）日期：2008.3.25院（部）：土木工程学院专业：土木工程班级：土木辅修091姓名：xxxx外文文献:Designing Against Fire Of BulidingxxxABSTRACT:This paper considers the design of buildings for fire safety. It is found that fire and the associ- ated effects on buildings is significantly different to other forms of loading such as gravity live loads, wind and earthquakes and their respective effects on the building structure. Fire events are derived from the human activities within buildings or from the malfunction of mechanical and electrical equipment provided within buildings to achieve a serviceable environment. It is therefore possible to directly influence the rate of fire starts within buildings by changing human behaviour, improved maintenance and improved design of mechanical and electrical systems. Furthermore, should a fire develops, it is possible to directly influence the resulting fire severity by the incorporation of fire safety systems such as sprinklers and to provide measures within the building to enable safer egress from the building. The ability to influence the rate of fire starts and the resulting fire severity is unique to the consideration of fire within buildings since other loads such as wind and earthquakes are directly a function of nature. The possible approaches for designing a building for fire safety are presented using an example of a multi-storey building constructed over a railway line. The design of both the transfer structure supporting the building over the railway and the levels above the transfer structure are considered in the context of current regulatory requirements. The principles and assumptions associ- ated with various approaches are discussed.1 INTRODUCTIONOther papers presented in this series consider the design of buildings for gravity loads, wind and earthquakes.The design of buildings against such load effects is to a large extent covered by engineering based standards referenced by the building regulations. This is not the case, to nearly the same extent, in the case of fire. Rather, it is building regulations such as the Building Code of Australia (BCA) that directly specify most of the requirements for fire safety of buildings with reference being made to Standards such as AS3600 or AS4100 for methods for determining the fire resistance of structural elements.The purpose of this paper is to consider the design of buildings for fire safety from an engineering perspective (as is currently done for other loads such as wind or earthquakes), whilst at the same time,putting such approaches in the context of the current regulatory requirements.At the outset,it needs to be noted that designing a building for fire safety is far morethan simply considering the building structure and whether it has sufficient structural adequacy.This is because fires can have a direct influence on occupants via smoke and heat and can grow in size and severity unlike other effects imposed on the building. Notwithstanding these comments, the focus of this paper will be largely on design issues associated with the building structure.Two situations associated with a building are used for the purpose of discussion. The multi-storey office building shown in Figure 1 is supported by a transfer structure that spans over a set of railway tracks. It is assumed that a wide range of rail traffic utilises these tracks including freight and diesel locomotives. The first situation to be considered from a fire safety perspective is the transfer structure.This is termed Situation 1 and the key questions are: what level of fire resistance is required for this transfer structure and how can this be determined? This situation has been chosen since it clearly falls outside the normal regulatory scope of most build- ing regulations. An engineering solution, rather than a prescriptive one is required. The second fire situation (termed Situation 2) corresponds to a fire within the office levels of the building and is covered by building regulations. This situation is chosen because it will enable a discussion of engineering approaches and how these interface with the building regulations–since both engineering and prescriptive solutions are possible.2 UNIQUENESS OF FIRE2.1 IntroductionWind and earthquakes can be considered to b e “natural” phenomena over which designers have no control except perhaps to choose the location of buildings more carefully on the basis of historical records and to design building to resist sufficiently high loads or accelerations for the particular location. Dead and live loads in buildings are the result of gravity. All of these loads are variable and it is possible (although generally unlikely) that the loads may exceed the resistance of the critical structural members resulting in structural failure.The nature and influence of fires in buildings are quite different to those associated with other“loads” to which a building may be subjected to. The essential differences are described in the following sections.2.2 Origin of FireIn most situations (ignoring bush fires), fire originates from human activities within the building or the malfunction of equipment placed within the building to provide a serviceable environment. It follows therefore that it is possible to influence the rate of fire starts by influencing human behaviour, limiting and monitoring human behaviour and improving thedesign of equipment and its maintenance. This is not the case for the usual loads applied to a building.2.3 Ability to InfluenceSince wind and earthquake are directly functions of nature, it is not possible to influence such events to any extent. One has to anticipate them and design accordingly. It may be possible to influence the level of live load in a building by conducting audits and placing restrictions on contents. However, in the case of a fire start, there are many factors that can be brought to bear to influence the ultimate size of the fire and its effect within the building. It is known that occupants within a building will often detect a fire and deal with it before it reaches a sig- nificant size. It is estimated that less than one fire in five (Favre, 1996) results in a call to the fire brigade and for fires reported to the fire brigade, the majority will be limited to the room of fire origin. In oc- cupied spaces, olfactory cues (smell) provide powerful evidence of the presence of even a small fire. The addition of a functional smoke detection system will further improve the likelihood of detection and of action being taken by the occupants.Fire fighting equipment, such as extinguishers and hose reels, is generally provided within buildings for the use of occupants and many organisations provide training for staff in respect of the use of such equipment.The growth of a fire can also be limited by automatic extinguishing systems such as sprinklers, which can be designed to have high levels of effectiveness.Fires can also be limited by the fire brigade depending on the size and location of the fire at the time of arrival. 2.4 Effects of FireThe structural elements in the vicinity of the fire will experience the effects of heat. The temperatures within the structural elements will increase with time of exposure to the fire, the rate of temperature rise being dictated by the thermal resistance of the structural element and the severity of the fire. The increase in temperatures within a member will result in both thermal expansion and,eventually,a reduction in the structural resistance of the member. Differential thermal expansion will lead to bowing of a member. Significant axial expansion will be accommodated in steel members by either overall or local buckling or yielding of local- ised regions. These effects will be detrimental for columns but for beams forming part of a floor system may assist in the development of other load resisting mechanisms (see Section 4.3.5).With the exception of the development of forces due to restraint of thermal expansion, fire does not impose loads on the structure but rather reduces stiffness and strength. Such effects are not instantaneous but are a function of time and this is different to the effects of loads such as earthquake and wind that are more or less instantaneous.Heating effects associated with a fire will not be significant or the rate of loss of capacity will be slowed if:(a) the fire is extinguished (e.g. an effective sprinkler system)(b) the fire is of insufficient severity – insufficient fuel, and/or(c)the structural elements have sufficient thermal mass and/or insulation to slow the rise in internal temperatureFire protection measures such as providing sufficient axis distance and dimensions for concrete elements, and sufficient insulation thickness for steel elements are examples of (c). These are illustrated in Figure 2.The two situations described in the introduction are now considered.3 FIRE WITHIN BUILDINGS3.1 Fire Safety ConsiderationsThe implications of fire within the occupied parts of the office building (Figure 1) (Situation 2) are now considered. Fire statistics for office buildings show that about one fatality is expected in an office building for every 1000 fires reported to the fire brigade. This is an order of magnitude less than the fatality rate associated with apartment buildings. More than two thirds of fires occur during occupied hours and this is due to the greater human activity and the greater use of services within the building. It is twice as likely that a fire that commences out of normal working hours will extend beyond the enclosure of fire origin.A relatively small fire can generate large quantities of smoke within the floor of fire origin. If the floor is of open-plan construction with few partitions, the presence of a fire during normal occupied hours is almost certain to be detected through the observation of smoke on the floor. The presence of full height partitions across the floor will slow the spread of smoke and possibly also the speed at which the occupants detect the fire. Any measures aimed at improving housekeeping, fire awareness and fire response will be beneficial in reducing thelikelihood of major fires during occupied hours.For multi-storey buildings, smoke detection systems and alarms are often provided to give “automatic” detection and warning to the occupants. An alarm signal is also transmitted to the fire brigade.Should the fire not be able to be controlled by the occupants on the fire floor, they will need to leave the floor of fire origin via the stairs. Stair enclosures may be designed to be fire-resistant but this may not be sufficient to keep the smoke out of the stairs. Many buildings incorporate stair pressurisation systems whereby positive airflow is introduced into the stairs upon detection of smoke within the building. However, this increases the forces required to open the stair doors and makes it increasingly difficult to access the stairs. It is quite likely that excessive door opening forces will exist(Fazio et al,2006)From a fire perspective, it is common to consider that a building consists of enclosures formed by the presence of walls and floors.An enclosure that has sufficiently fire-resistant boundaries (i.e. walls and floors) is considered to constitute a fire compartment and to be capable of limiting the spread of fire to an adjacent compartment. However, the ability of such boundaries to restrict the spread of fire can be severely limited by the need to provide natural lighting (windows)and access openings between the adjacent compartments (doors and stairs). Fire spread via the external openings (windows) is a distinct possibility given a fully developed fire. Limit- ing the window sizes and geometry can reduce but not eliminate the possibility of vertical fire spread.By far the most effective measure in limiting fire spread, other than the presence of occupants, is an effective sprinkler system that delivers water to a growing fire rapidly reducing the heat being generated and virtually extinguishing it.3.2 Estimating Fire SeverityIn the absence of measures to extinguish developing fires, or should such systems fail; severe fires can develop within buildings.In fire en gineering literature, the term “fire load” refers to the quantity of combustibles within an enclosure and not the loads (forces) applied to the structure during a fire. Similarly, fire load density refers to the quantity of fuel per unit area. It is normally expressed in terms of MJ/m2 or kg/m2 of wood equivalent. Surveys of combustibles for various occupancies (i.e offices, retail, hospitals, warehouses, etc)have been undertaken and a good summary of the available data is given in FCRC (1999). As would be expected, the fire load density is highly variable. Publications such as the International Fire Engineering Guidelines (2005) give fire load data in terms of the mean and 80th percentile.The latter level of fire load density is sometimes taken asthe characteristic fire load density and is sometimes taken as being distributed according to a Gumbel distribution (Schleich et al, 1999).The rate at which heat is released within an enclosure is termed the heat release rate (HRR) and normally expressed in megawatts (MW). The application of sufficient heat to a combustible material results in the generation of gases some of which are combustible. This process is called pyrolisation.Upon coming into contact with sufficient oxygen these gases ignite generating heat. The rate of burning(and therefore of heat generation) is therefore dependent on the flow of air to the gases generated by the pyrolising fuel.This flow is influenced by the shape of the enclosure (aspect ratio), and the position and size of any potential openings. It is found from experiments with single openings in approximately cubic enclosures that the rate of burning is directly proportional to A h where A is the area of the opening and h is the opening height. It is known that for deep enclosures with single openings that burning will occur initially closest to the opening moving back into the enclosure once the fuel closest to the opening is consumed (Thomas et al, 2005). Significant temperature variations throughout such enclosures can be expected.The use of the word ‘opening’ in relation to real building enclosures refers to any openings present around the walls including doors that are left open and any windows containing non fire-resistant glass.It is presumed that such glass breaks in the event of development of a significant fire. If the windows could be prevented from breaking and other sources of air to the enclosure limited, then the fire would be prevented from becoming a severe fire.Various methods have been developed for determining the potential severity of a fire within an enclosure.These are described in SFPE (2004). The predictions of these methods are variable and are mostly based on estimating a representative heat release rate (HRR) and the proportion of total fuel ςlikely to be consumed during the primary burning stage (Figure 4). Further studies of enclosure fires are required to assist with the development of improved models, as the behaviour is very complex.3.3 Role of the Building StructureIf the design objectives are to provide an adequate level of safety for the occupants and protection of adjacent properties from damage, then the structural adequacy of the building in fire need only be sufficient to allow the occupants to exit the building and for the building to ultimately deform in a way that does not lead to damage or fire spread to a building located on an adjacent site.These objectives are those associated with most building regulations includingthe Building Code of Australia (BCA). There could be other objectives including protection of the building against significant damage. In considering these various objectives, the following should be taken into account when considering the fire resistance of the building structure.3.3.1 Non-Structural ConsequencesSince fire can produce smoke and flame, it is important to ask whether these outcomes will threaten life safety within other parts of the building before the building is compromised by a loss of structural adequacy? Is search and rescue by the fire brigade not feasible given the likely extent of smoke? Will the loss of use of the building due to a severe fire result in major property and income loss? If the answer to these questions is in the affirmative, then it may be necessary to minimise the occurrence of a significant fire rather than simply assuming that the building structure needs to be designed for high levels of fire resistance. A low-rise shopping centre with levels interconnected by large voids is an example of such a situation.3.3.2 Other Fire Safety SystemsThe presence of other systems (e.g. sprinklers) within the building to minimise the occurrence of a serious fire can greatly reduce the need for the structural elements to have high levels of fire resistance. In this regard, the uncertainties of all fire-safety systems need to be considered. Irrespective of whether the fire safety system is the sprinkler system, stair pressurisation, compartmentation or the system giving the structure a fire-resistance level (e.g. concrete cover), there is an uncertainty of performance. Uncertainty data is available for sprinkler systems(because it is relatively easy to collect) but is not readily available for the other fire safety systems. This sometimes results in the designers and building regulators considering that only sprinkler systems are subject to uncertainty. In reality, it would appear that sprinklers systems have a high level of performance and can be designed to have very high levels of reliability.3.3.3 Height of BuildingIt takes longer for a tall building to be evacuated than a short building and therefore the structure of a tall building may need to have a higher level of fire resistance. The implications of collapse of tall buildings on adjacent properties are also greater than for buildings of only several storeys.3.3.4 Limited Extent of BurningIf the likely extent of burning is small in comparison with the plan area of the building, then the fire cannot have a significant impact on the overall stability of the building structure. Examples of situations where this is the case are open-deck carparks and very large area building such as shopping complexes where the fire-effected part is likely to be small in relation to area of the building floor plan.3.3.5 Behaviour of Floor ElementsThe effect of real fires on composite and concrete floors continues to be a subject of much research.Experimental testing at Cardington demonstrated that when parts of a composite floor are subject to heating, large displacement behaviour can develop that greatly assists the load carrying capacity of the floor beyond that which would predicted by considering only the behaviour of the beams and slabs in isolation.These situations have been analysed by both yield line methods that take into account the effects of membrane forces (Bailey, 2004) and finite element techniques. In essence, the methods illustrate that it is not necessary to insulate all structural steel elements in a composite floor to achieve high levels of fire resistance.This work also demonstrated that exposure of a composite floor having unprotected steel beams, to a localised fire, will not result in failure of the floor.A similar real fire test on a multistory reinforced concrete building demonstrated that the real structural behaviour in fire was significantly different to that expected using small displacement theory as for normal tempera- ture design (Bailey, 2002) with the performance being superior than that predicted by considering isolated member behaviour.3.4 Prescriptive Approach to DesignThe building regulations of most countries provide prescriptive requirements for the design of buildings for fire.These requirements are generally not subject to interpretation and compliance with them makes for simpler design approval–although not necessarily the most cost-effective designs.These provisions are often termed deemed-to-satisfy (DTS) provisions. All aspects of designing buildings for fire safety are covered–the provision of emergency exits, spacings between buildings, occupant fire fighting measures, detection and alarms, measures for automatic fire suppression, air and smoke handling requirements and last, but not least, requirements for compartmentation and fire resistance levels for structural members. However, there is little evidence that the requirements have been developed from a systematic evaluation of fire safety. Rather it would appear that many of the requirements have been added one to another to deal with another fire incident or to incorporate a new form of technology. There does not appear to have been any real attempt to determine which provision have the most significant influence on fire safety and whether some of the former provisions could be modified.The FRL requirements specified in the DTS provisions are traditionally considered to result in member resistances that will only rarely experience failure in the event of a fire.This is why it is acceptable to use the above arbitrary point in time load combination for assessing members in fire. There have been attempts to evaluate the various deemed-to-satisfy provisions (particularly the fire- resistance requirements)from a fire-engineering perspective taking intoaccount the possible variations in enclosure geometry, opening sizes and fire load (see FCRC, 1999).One of the outcomes of this evaluation was the recognition that deemed-to- satisfy provisions necessarily cover the broad range of buildings and thus must, on average, be quite onerous because of the magnitude of the above variations.It should be noted that the DTS provisions assume that compartmentation works and that fire is limited to a single compartment. This means that fire is normally only considered to exist at one level. Thus floors are assumed to be heated from below and columns only over one storey height.3.5 Performance-Based DesignAn approach that offers substantial benefits for individual buildings is the move towards performance-based regulations. This is permitted by regulations such as the BCA which state that a designer must demonstrate that the particular building will achieve the relevant performance requirements. The prescriptive provisions (i.e. the DTS provisions) are presumed to achieve these requirements. It is necessary to show that any building that does not conform to the DTS provisions will achieve the performance requirements.But what are the performance requirements? Most often the specified performance is simply a set of performance statements (such as with the Building Code of Australia)with no quantitative level given. Therefore, although these statements remind the designer of the key elements of design, they do not, in themselves, provide any measure against which to determine whether the design is adequately safe.Possible acceptance criteria are now considered.3.5.1 Acceptance CriteriaSome guidance as to the basis for acceptable designs is given in regulations such as the BCA. These and other possible bases are now considered in principle.(i)compare the levels of safety (with respect to achieving each of the design objectives) of the proposed alternative solution with those asso- ciated with a corresponding DTS solution for the building.This comparison may be done on either a qualitative or qualitative risk basis or perhaps a combination. In this case, the basis for comparison is an acceptable DTS solution. Such an approach requires a “holistic” approach to safety whereby all aspects relevant to safety, including the structure, are considered. This is, by far, the most common basis for acceptance.(ii)undertake a probabilistic risk assessment and show that the risk associated with the proposed design is less than that associated with common societal activities such as using pub lic transport. Undertaking a full probabilistic risk assessment can be very difficult for all but the simplest situations.Assuming that such an assessment is undertaken it will be necessary for the stakeholders to accept the nominated level of acceptable risk. Again, this requires a “holistic”approach to fire safety.(iii) a design is presented where it is demonstrated that all reasonable measures have been adopted to manage the risks and that any possible measures that have not been adopted will have negligible effect on the risk of not achieving the design objectives.(iv) as far as the building structure is concerned,benchmark the acceptable probability of failure in fire against that for normal temperature design. This is similar to the approach used when considering Building Situation 1 but only considers the building structure and not the effects of flame or smoke spread. It is not a holistic approach to fire safety.Finally, the questions of arson and terrorism must be considered. Deliberate acts of fire initiation range from relatively minor incidents to acts of mass destruction.Acts of arson are well within the accepted range of fire events experienced by build- ings(e.g. 8% of fire starts in offices are deemed "suspicious"). The simplest act is to use a small heat source to start a fire. The resulting fire will develop slowly in one location within the building and will most probably be controlled by the various fire- safety systems within the building. The outcome is likely to be the same even if an accelerant is used to assist fire spread.An important illustration of this occurred during the race riots in Los Angeles in 1992 (Hart 1992) when fires were started in many buildings often at multiple locations. In the case of buildings with sprinkler systems,the damage was limited and the fires significantly controlled.Although the intent was to destroy the buildings,the fire-safety systems were able to limit the resulting fires. Security measures are provided with systems such as sprinkler systems and include:- locking of valves- anti-tamper monitoring- location of valves in secure locationsFurthermore, access to significant buildings is often restricted by security measures.The very fact that the above steps have been taken demonstrates that acts of destruction within buildings are considered although most acts of arson do not involve any attempt to disable the fire-safety systems.At the one end of the spectrum is "simple" arson and at the other end, extremely rare acts where attempts are made to destroy the fire-safety systems along with substantial parts of the building.This can be only achieved through massive impact or the use of explosives. The latter may be achieved through explosives being introduced into the building or from outside by missile attack.The former could result from missile attack or from the collision of a large aircraft. The greater the destructiveness of the act,the greater the means and knowledge required. Conversely, the more extreme the act, the less confidence there can be in designing against suchan act. This is because the more extreme the event, the harder it is to predict precisely and the less understood will be its effects. The important point to recognise is that if sufficient means can be assembled, then it will always be possible to overcome a particular building design.Thus these acts are completely different to the other loadings to which a building is subjected such as wind,earthquake and gravity loading. This is because such acts of destruction are the work of intelligent beings and take into account the characteristics of the target.Should high-rise buildings be designed for given terrorist activities,then terrorists will simply use greater means to achieve the end result.For example, if buildings were designed to resist the impact effects from a certain size aircraft, then the use of a larger aircraft or more than one aircraft could still achieve destruction of the building. An appropriate strategy is therefore to minimise the likelihood of means of mass destruction getting into the hands of persons intent on such acts. This is not an engineering solution associated with the building structure.It should not be assumed that structural solutions are always the most appropriate, or indeed, possible.In the same way, aircrafts are not designed to survive a major fire or a crash landing but steps are taken to minimise the likelihood of either occurrence.The mobilization of large quantities of fire load (the normal combustibles on the floors) simultaneously on numerous levels throughout a building is well outside fire situations envisaged by current fire test standards and prescriptive regulations. Risk management measures to avoid such a possibility must be considered.4 CONCLUSIONSFire differs significantly from other “loads” such as wind, live load and earthquakes i n respect of its origin and its effects.Due to the fact that fire originates from human activities or equipment installed within buildings, it is possible to directly influence the potential effects on the building by reducing the rate of fire starts and providing measures to directly limit fire severity.The design of buildings for fire safety is mostly achieved by following the prescriptive requirements of building codes such as the BCA. For situations that fall outside of the scope of such regulations, or where proposed designs are not in accordance with the prescriptive requirements, it is possible to undertake performance-based fire engineering designs.However, there are no design codes or standards or detailed methodologies available for undertaking such designs.Building regulations require that such alternative designs satisfy performance requirements and give some guidance as to the basis for acceptance of these designs (i.e. acceptance criteria).This paper presents a number of possible acceptance criteria, all of which use the measure of risk level as the basis for comparison.Strictly, when considering the risks。

毕业设计论文电子秤中英文外文资料文献翻译

外文参考资料二：Abstract: In order to solve the weight problem often encountered in measuring the low-mass objects in the trade and daily life of the modern business, the design of a new pocket-sized electronic scales. This pocket-sized electronic scales Force Sensor gravity signals into electrical signals to measure, and measuring the results of the digital display. The pocket-sized electronic scales with a small size, light weight, easy to carry, intuitive display, measurement and high precision; complex structure, the cost disadvantages. This article focuses on the load cell works, error compensation, the main parameters of selection. And the technical and economic analysis.Keywords: pocket-sized electronic scales; weighing; sensor; error compensationCLC number: TH715. 1] sign code: A Article ID: 100 522 895 (2007) 022*******1 A needs analysisIn modern commerce and trade and everyday life, often encounter the problem of measuring the weight of the low-mass objects. Although the traditional steelyard can solve this problem, but inconvenient to carry, the efficiency is not high, the display is not intuitive and low measurement accuracy; mechanical spring balance can solve this problem, but the inertia inherent low frequency, high sensitivity, measurement accuracy is not high. With the progress and update of the micro-computer technology, integrated circuit technology, sensor technology, electronic scales rapiddevelopment, it has a responsive, high accuracy, fully functional, the display is intuitive, compact, easy to use and so on.For these reasons, in order to solve the low-mass objects weighing problem, if a small size, light weight, portable, digital display electronic scales, will be popular. Discussed below, that is, the scope of a weighing 5 kg compact electronic scales.2 DesignThe principle of the structure of the pocket-sized electronic scales shown in Figure 1. The main task is to design compact electronic scales weighing the choice of the force sensors. Dynamometer sensor types to achieve the weighing and digital display, the key is to want to force (gravity) signals into electrical signals to measure method is mainly divided into two categories: one is the direct method, namely the use of pressure magnetic sensor, piezoelectric sensor, Piezoresistive sensors directly to the force signal converted into electrical signals; the other is the indirect method, the elastic element as the sensor will pull, pressure changes in strain, displacement, or frequency, and then strain sensors, displacement sensors, or frequency sensor strain, displacement or frequency changes for power. Comprehensive comparison of a variety of sensors, use the indirect method of strain gauge force transducer.Pocket-sized electronic scale structural principle:Sensor → amplifier → CPU→ display → AöD converter3 sensor device design3.1 worksThe working principle of the strain gauge force transducer strain gauge pasted into force, force-sensitive elasticelement, the corresponding strain when the elastic element force deformation, the strain gauge into a resistance change, which led to the voltage measuring circuit changes by measuring the output voltage value, and then through the conversion can be obtained by the measurement of body weight. Since the pocket-sized electronic scales require small size, weighing in scope, precision and angle even consistency, sensor and display integration, it is selected parallel to the two holes cantilever beam strain gauge load-bearing sensor. Its characteristics are: high precision, ease of processing, simple and compact structure, strong resistance to partial load, high natural frequency.Strain gauge choice of a metal palisade metal mooring paste on the insulating substrate parked strain gages, mechanical strain resistance strain gauge feelings generally 10 - 10 - 2mm, the resistance rate of change of the attendant about 10 - 6 10 - 2 orders of magnitude, such a small change in resistance measured using the general resistance of the instrument is hard to measure out, you must use some form of measurement.Circuit into small changes in resistance rates to changes in voltage or current, in order to secondary instrument display. Bridge measurement circuit to meet this requirement. In the load cell, R 1, R 2, R 3, R 44 strain gauge resistor bridge measurement circuit shown in Figure 3. R m is the temperature compensation resistor, e is the excitation voltage, V is the output voltage.外文参考资料三：The load cell is a quality signal into a measurable electrical signal outputdevice. Must consider the actual working environment of the sensor which sensor Yin, this is essential for the correct selection of the load cell, and it is related to the sensor can work as well as its safety and service life, and the whole weighing the reliability and safety sex. On the basic concepts and methods of evaluation of the major technical indicators of the load cell, the new and old GB qualitative differences.The traditional concept, the load sensor weighing sensors, force sensors, collectively referred to using a single parameter to evaluate its measurement properties. Old GB will be completely different application objects and the use of environmental conditions "weighing" and "measured force" two sensors into one to consider, not given to distinguish between the test and evaluation methods. Old GB total of 21 indicators, were tested at room temperature; and non-linearity, hysteresis error, repeatability error, creep, the additional error of the zero temperature and the maximum error in the six indicators of the rated output additional temperature error, to determine said The level of accuracy of the weight sensor, respectively 0.02,0.03,0.05 said.Proportion to convert the output signal can be measured. Taking into account the different place of use of the acceleration due to gravity and air buoyancy on the conversion, the main performance indicators of the load cell linearity error, hysteresis error, repeatability error, creep, zero-temperature characteristics and temperature sensitivity characteristics. In a variety of weighing and measuring the quality of the system, usually the integrated error accuracy of the integrated control sensors, and integrated error band or scale error band (Figure 1) linked so that selection corresponds to a certain accuracy weighing weighing sensors. International Organization of Legal Metrology(OIML) requirements, sensor error with total weighing instrument error δ with Δ of 70% of the load cell linearity error, hysteresis error within the specified temperature range due to the effect of temperature on the sensitivity of the error the sum can not exceed the error band of δ. This allows the manufacturer of the components that make up the total measurement error adjustment to obtain the desired accuracy.The load cell conversion method is divided into photoelectric, hydraulic, electromagnetic force type, capacitive, magnetic poles change the form of vibratory gyroscope ceremony, resistance strain type, to the most extensive use of resistance strain.Electromagnetic force sensorIt uses a load-bearing stage load and the principle of electromagnetic force Equilibrium (Figure 5). Put the loading stage, the measured object at one end of the lever upward tilt; photoelectric detect the tilt signal, amplified into the coil, the electromagnetic force, so that the lever to return to equilibrium. Currents produce electromagnetic counterweight digital converter, you can determine the quality of the measured object. The electromagnetic force sensor accuracy, up to 1/2000 ~ 1/60000, but the weighing range is only tens of mg to 10 kg.Capacitive sensorsItcapacitor oscillator circuit of the oscillation frequency f and the plate spacing d is directly proportional relationship between the work (Figure 6). There are two plates, one fixed and the other one can move. Bearing load measured object, the leaf spring deflection, the distance between the twoplates changes, the oscillation frequency of the circuit also changes. The measured frequency change can be calculated to the quality of the load-bearing stage, the measured object. Capacitive sensor power consumption, low cost, accuracy of 1/200 to 1/500.Pole change the form of sensorFerromagneticcomponents in the measured object gravity under mechanical deformation, internal stress and cause changes in permeability, and also changes so that the induced voltage of the secondary coil wound on both sides of the ferromagnetic component (pole). Measure the voltage variation can be calculated added to the force on the pole, and then determine the quality of the measured object. Pole to change the form of sensor accuracy is not high, usually 1/100, applicable to the large tonnage weighing, weighing ranging from tens to tens of thousands of kilograms.Vibration sensorThe force of the elastic element, the natural vibration frequency of the force is proportional to the square root of. Measure the natural frequency changes, you can find the measured object role in the elastic component of the force, and then calculate the quality. The vibration sensor vibrating wire and tuning fork.The elastic component of the vibrating wire sensor string wire. When the load-bearing stage, plus the measured object, the intersection of the V-shaped string wire is pulled down, and left strings of tension increases, the right string tension decreases. The natural frequency of the two strings of different changes. Calculate the frequency difference between the two strings, you can find the quality of the measured object. The higher the accuracy of the vibrating wire sensor, up to 1/1000 ~ 1/10000, weighing 100 g to hundreds of kilograms, but the structure is complex anddifficult process, and high cost.The elastic component of the tuning fork sensor is a tuning fork. Fixed tuning fork end of the piezoelectric element, the natural frequency of oscillation of a tuning fork, it can be measured oscillation frequency. When the load-bearing stage and the measured object, the tuning fork direction of tensile force while the increase in natural frequency, increasing levels of applied force is proportional to the square root. Measure the changes of natural frequency can be calculated heavy loads imposed on the tuning fork on the force, and then calculate the quality of heavy objects. The tuning fork sensor power consumption, measurement accuracy up to 1/10000 to 1/200 000, weighing range of 500g ~ 10kg.外文参考文献中文翻译参考资料二：摘要: 为解决现代商业贸易和日常生活中经常遇到的测量小质量物体的重量问题, 介绍了一种新型的袖珍式电子秤的设计。

毕业设计(论文)外文资料翻译(学生用)

毕业设计外文资料翻译学院：信息科学与工程学院专业：软件工程姓名： XXXXX学号： XXXXXXXXX外文出处： Think In Java (用外文写)附件： 1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂，而且极易出错。

程序员必须掌握与网络有关的大量细节，有时甚至要对硬件有深刻的认识。

一般地，我们需要理解连网协议中不同的“层”（Layer）。

而且对于每个连网库，一般都包含了数量众多的函数，分别涉及信息块的连接、打包和拆包；这些块的来回运输；以及握手等等。

这是一项令人痛苦的工作。

但是，连网本身的概念并不是很难。

我们想获得位于其他地方某台机器上的信息，并把它们移到这儿；或者相反。

这与读写文件非常相似，只是文件存在于远程机器上，而且远程机器有权决定如何处理我们请求或者发送的数据。

Java最出色的一个地方就是它的“无痛苦连网”概念。

有关连网的基层细节已被尽可能地提取出去，并隐藏在JVM以及Java的本机安装系统里进行控制。

我们使用的编程模型是一个文件的模型；事实上，网络连接（一个“套接字”）已被封装到系统对象里，所以可象对其他数据流那样采用同样的方法调用。

除此以外，在我们处理另一个连网问题——同时控制多个网络连接——的时候，Java内建的多线程机制也是十分方便的。

本章将用一系列易懂的例子解释Java的连网支持。

15.1 机器的标识当然，为了分辨来自别处的一台机器，以及为了保证自己连接的是希望的那台机器，必须有一种机制能独一无二地标识出网络内的每台机器。

早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。

但Java面向的是整个因特网，这要求用一种机制对来自世界各地的机器进行标识。

为达到这个目的，我们采用了IP（互联网地址）的概念。

IP以两种形式存在着：(1) 大家最熟悉的DNS（域名服务）形式。

我自己的域名是。

所以假定我在自己的域内有一台名为Opus的计算机，它的域名就可以是。

外文参考文献(带中文翻译)

外文资料原文涂敏之会计学 8051208076Title:Future of SME finance（c）Background – the environment for SME finance has changedFuture economic recovery will depend on the possibility of Crafts, Trades and SMEs to exploit their potential for growth and employment creation.SMEs make a major contribution to growth and employment in the EU and are at the heart of the Lisbon Strategy, whose main objective is to turn Europe into the most competitive and dynamic knowledge-based economy in the world. However, the ability of SMEs to grow depends highly on their potential to invest in restructuring, innovation and qualification. All of these investments need capital and therefore access to finance.Against this background the consistently repeated complaint of SMEs about their problems regarding access to finance is a highly relevant constraint that endangers the economic recovery of Europe.Changes in the finance sector influence the behavior of credit institutes towards Crafts, Trades and SMEs. Recent and ongoing developments in the banking sector add to the concerns of SMEs and will further endanger their access to finance. The main changes in the banking sector which influence SME finance are:•Globalization and internationalization have increased the competition and the profit orientation in the sector;•worsening of the economic situations in some institutes (burst of the ITC bubble, insolvencies) strengthen the focus on profitability further;•Mergers and restructuring created larger structures and many local branches, which had direct and personalized contacts with small enterprises, were closed;•up-coming implementation of new capital adequacy rules (Basel II) will also change SME business of the credit sector and will increase its administrative costs;•Stricter interpretation of State-Aide Rules by the European Commission eliminates the support of banks by public guarantees; many of the effected banks are very active in SME finance.All these changes result in a higher sensitivity for risks and profits in the financesector.The changes in the finance sector affect the accessibility of SMEs to finance.Higher risk awareness in the credit sector, a stronger focus on profitability and the ongoing restructuring in the finance sector change the framework for SME finance and influence the accessibility of SMEs to finance. The most important changes are: •In order to make the higher risk awareness operational, the credit sector introduces new rating systems and instruments for credit scoring;•Risk assessment of SMEs by banks will force the enterprises to present more and better quality information on their businesses;•Banks will try to pass through their additional costs for implementing and running the new capital regulations (Basel II) to their business clients;•due to the increase of competition on interest rates, the bank sector demands more and higher fees for its services (administration of accounts, payments systems, etc.), which are not only additional costs for SMEs but also limit their liquidity;•Small enterprises will lose their personal relationship with decision-makers in local branches –the credit application process will become more formal and anonymous and will probably lose longer;•the credit sector will lose more and more i ts “public function” to provide access to finance for a wide range of economic actors, which it has in a number of countries, in order to support and facilitate economic growth; the profitability of lending becomes the main focus of private credit institutions.All of these developments will make access to finance for SMEs even more difficult and / or will increase the cost of external finance. Business start-ups and SMEs, which want to enter new markets, may especially suffer from shortages regarding finance. A European Code of Conduct between Banks and SMEs would have allowed at least more transparency in the relations between Banks and SMEs and UEAPME regrets that the bank sector was not able to agree on such a commitment.Towards an encompassing policy approach to improve the access of Crafts, Trades and SMEs to financeAll analyses show that credits and loans will stay the main source of finance for the SME sector in Europe. Access to finance was always a main concern for SMEs, but the recent developments in the finance sector worsen the situation even more.Shortage of finance is already a relevant factor, which hinders economic recovery in Europe. Many SMEs are not able to finance their needs for investment.Therefore, UEAPME expects the new European Commission and the new European Parliament to strengthen their efforts to improve the framework conditions for SME finance. Europe’s Crafts, Trades and SMEs ask for an encompassing policy approach, which includes not only the conditions for SMEs’ access to l ending, but will also strengthen their capacity for internal finance and their access to external risk capital.From UEAPME’s point of view such an encompassing approach should be based on three guiding principles:•Risk-sharing between private investors, financial institutes, SMEs and public sector;•Increase of transparency of SMEs towards their external investors and lenders;•improving the regulatory environment for SME finance.Based on these principles and against the background of the changing environment for SME finance, UEAPME proposes policy measures in the following areas:1. New Capital Requirement Directive: SME friendly implementation of Basel IIDue to intensive lobbying activities, UEAPME, together with other Business Associations in Europe, has achieved some improvements in favour of SMEs regarding the new Basel Agreement on regulatory capital (Basel II). The final agreement from the Basel Committee contains a much more realistic approach toward the real risk situation of SME lending for the finance market and will allow the necessary room for adaptations, which respect the different regional traditions and institutional structures.However, the new regulatory system will influence the relations between Banks and SMEs and it will depend very much on the way it will be implemented into European law, whether Basel II becomes burdensome for SMEs and if it will reduce access to finance for them.The new Capital Accord form the Basel Committee gives the financial market authorities and herewith the European Institutions, a lot of flexibility. In about 70 areas they have room to adapt the Accord to their specific needs when implementing itinto EU law. Some of them will have important effects on the costs and the accessibility of finance for SMEs.UEAPME expects therefore from the new European Commission and the new European Parliament:•The implementation of the new Capital Requirement Directive will be costly for the Finance Sector (up to 30 Billion Euro till 2006) and its clients will have to pay for it. Therefore, the implementation – especially for smaller banks, which are often very active in SME finance –has to be carried out with as little administrative burdensome as possible (reporting obligations, statistics, etc.).•The European Regulators must recognize traditional instruments for collaterals (guarantees, etc.) as far as possible.•The European Commission and later the Member States should take over the recommendations from the European Parliament with regard to granularity, access to retail portfolio, maturity, partial use, adaptation of thresholds, etc., which will ease the burden on SME finance.2. SMEs need transparent rating proceduresDue to higher risk awareness of the finance sector and the needs of Basel II, many SMEs will be confronted for the first time with internal rating procedures or credit scoring systems by their banks. The bank will require more and better quality information from their clients and will assess them in a new way. Both up-coming developments are already causing increasing uncertainty amongst SMEs.In order to reduce this uncertainty and to allow SMEs to understand the principles of the new risk assessment, UEAPME demands transparent rating procedures –rating procedures may not become a “Black Box” for SMEs: •The bank should communicate the relevant criteria affecting the rating of SMEs.•The bank should inform SMEs about its assessment in order to allow SMEs to improve.The negotiations on a European Code of Conduct between Banks and SMEs , which would have included a self-commitment for transparent rating procedures by Banks, failed. Therefore, UEAPME expects from the new European Commission and the new European Parliament support for:•binding rules in the framework of the new Capital Adequacy Directive,which ensure the transparency of rating procedures and credit scoring systems for SMEs;•Elaboration of national Codes of Conduct in order to improve the relations between Banks and SMEs and to support the adaptation of SMEs to the new financial environment.3. SMEs need an extension of credit guarantee systems with a special focus on Micro-LendingBusiness start-ups, the transfer of businesses and innovative fast growth SMEs also depended in the past very often on public support to get access to finance. Increasing risk awareness by banks and the stricter interpretation of State Aid Rules will further increase the need for public support.Already now, there are credit guarantee schemes in many countries on the limit of their capacity and too many investment projects cannot be realized by SMEs.Experiences show that Public money, spent for supporting credit guarantees systems, is a very efficient instrument and has a much higher multiplying effect than other instruments. One Euro form the European Investment Funds can stimulate 30 Euro investments in SMEs (for venture capital funds the relation is only 1:2).Therefore, UEAPME expects the new European Commission and the new European Parliament to support:•The extension of funds for national credit guarantees schemes in the framework of the new Multi-Annual Programmed for Enterprises;•The development of new instruments for securitizations of SME portfolios;•The recognition of existing and well functioning credit guarantees schemes as collateral;•More flexibility within the European Instruments, because of national differences in the situation of SME finance;•The development of credit guarantees schemes in the new Member States;•The development of an SBIC-like scheme in the Member States to close the equity gap (0.2 – 2.5 Mio Euro, according to the expert meeting on PACE on April 27 in Luxemburg).•the development of a financial support scheme to encourage the internalizations of SMEs (currently there is no scheme available at EU level: termination of JOP, fading out of JEV).4. SMEs need company and income taxation systems, whichstrengthen their capacity for self-financingMany EU Member States have company and income taxation systems with negative incentives to build-up capital within the company by re-investing their profits. This is especially true for companies, which have to pay income taxes. Already in the past tax-regimes was one of the reasons for the higher dependence of Europe’s SMEs on bank lending. In future, the result of rating w ill also depend on the amount of capital in the company; the high dependence on lending will influence the access to lending. This is a vicious cycle, which has to be broken.Even though company and income taxation falls under the competence of Member States, UEAPME asks the new European Commission and the new European Parliament to publicly support tax-reforms, which will strengthen the capacity of Crafts, Trades and SME for self-financing. Thereby, a special focus on non-corporate companies is needed.5. Risk Capital – equity financingExternal equity financing does not have a real tradition in the SME sector. On the one hand, small enterprises and family business in general have traditionally not been very open towards external equity financing and are not used to informing transparently about their business.On the other hand, many investors of venture capital and similar forms of equity finance are very reluctant regarding investing their funds in smaller companies, which is more costly than investing bigger amounts in larger companies. Furthermore it is much more difficult to set out of such investments in smaller companies.Even though equity financing will never become the main source of financing for SMEs, it is an important instrument for highly innovative start-ups and fast growing companies and it has therefore to be further developed. UEAPME sees three pillars for such an approach where policy support is needed:Availability of venture capital•The Member States should review their taxation systems in order to create incentives to invest private money in all forms of venture capital.•Guarantee instruments for equity financing should be further developed.Improve the conditions for investing venture capital into SMEs•The development of secondary markets for venture capital investments in SMEs should be supported.•Accounting Standards for SMEs should be revised in order to easetransparent exchange of information between investor and owner-manager.Owner-managers must become more aware about the need for transparency towards investors•SME owners will have to realise that in future access to external finance (venture capital or lending) will depend much more on a transparent and open exchange of information about the situation and the perspectives of their companies.•In order to fulfil the new needs for transparency, SMEs will have to use new information instruments (business plans, financial reporting, etc.) and new management instruments (risk-management, financial management, etc.).外文资料翻译涂敏之会计学 8051208076题目：未来的中小企业融资背景：中小企业融资已经改变未来的经济复苏将取决于能否工艺品，贸易和中小企业利用其潜在的增长和创造就业。

外文文献

英文文献资料外文文献一：Food safety: the shocking truth about the food industrySource: Author: Marion Nestle、Refrigeration technology, pasteurization, pesticides, disease control, these technologies so that safe food into the 20th century, public health's greatest achievements. This book view is that food safety problems also depend on politics. September 2001 events to dispel this view of the doubts about aviation aircraft used by terrorists as a destruction of weapons to civilians and public figures have anthrax spores sent folder of letters, the consequences of these events shows, food, water can easily become a a tool for terrorists, it has also become the federal government for food safety control problem.This chapter will sum up this book referred to in the various food safety problems. Some of them threatened to keep animals healthy, very few will lead to a number of human diseases. Even so, these issues impact on human well-being is deep; large-scale destruction of breeding animals, affecting the livelihood of many people, limiting personal freedom. The 20th century, 90's and early 21st century, an outbreak of mad cow disease and foot and mouth disease Although this is only because of errors caused by the production process, but still brings a lot of destructive. In contrast, bio-terrorism is the deliberate use of biological and chemical substances to achieve their political objectives. For food safety issues,Bio-terrorism extends food safety issues and political outreach; deliberate destruction, excluding any consequences of innocent injury.In this chapter, we will discuss how the rise of bio-terrorism, food safety issues and extend the extension of food safety issues. In the United States, food safety, usually refers to the family food supply reliability. E-mail from the anthrax incident, the food safety issues, also includes safety from biological terrorism. Our discussion will be the beginning of some zoonotic diseases: such as mad cow disease, foot and mouth disease, anthrax. In recent years, these zoonotic diseases harmful to humans is relatively small. Today, for these zoonotic diseases, we are concerned that they may give rise to disease, destruction of food supply system,To become a tool for bio-terrorism aspect. This chapter summarizes the discussion of this book, fromsociety and from a personal point of view what action should be taken to face these issues, as well as food safety issues present and future.The political animal diseasesOne of the consequences of globalization is that of food cross-border long-distance rapid transit, affecting food supply all kinds of disease can easily spread from one country to another country. Animal diseases have a commercial impact, if a country has come to infectious diseases of animals, other countries will refuse to import the kinds of animal meat. The impact of business at the same time there are political consequences.Britain's mad cow disease and foot and mouth disease occurred as a result of beef in the production process caused by mismanagement, compared to the U.S. anthrax letters is a result of vandalism. However, this three kinds of threatening to cause great panic, they are difficult to detect control, can cause severe disease. Moreover, these three kinds of threats against people for the food supply, as well as confidence in the Government.Mad cow is the mid-20th century, 90 of the most popular of a food security crisis, the epidemic is mainly limited to the United Kingdom. With regard to BSE-related issues and our discussion, mainly because of political issues and scientific issues intertwined Among them, public confidence had a great impact. For example, the British Government in the BSE crisis in the practice is also considered to result in distrust of genetically modified food one of the reasons. The beginning of the 20th century, 80 years, no one had heard of the disease, but in 1999, this disease affects at least 175,000 British cattle. The consequences are very serious: 400 million head of livestock were slaughtered, the loss of 70 billion U.S. dollars,Spread to 18 countries worldwide national boycott of British beef. By 2001 only, although "only" 120 people died of the human variant of mad cow disease, it is estimated the death toll will reach 10 million people. Because mad cow disease revealed the modern politics of food safety issues, it is worth detailing.英文文献中文翻译06013618 胡冬敏外文翻译一：作者：玛丽恩·内斯特尔出版时间：2004年11月食品安全：令人震惊的食品行业真相（美）玛丽恩·内斯特尔冷藏技术，巴氏消毒，杀虫剂，疾病控制，这些技术使安全食品成为20世纪公众健康最伟大的成就之一。

材料英文翻译

外文资料与中文翻译外文资料：Influence of machining parameters on the machineability of particulate reinforced Al/SiC–MMCAbstract: the paper presents the result of an experimental investigation on the mach inability of silicon carbide particulate aluminum metal matrix composite during turning using a rhombic uncoated carbide tool. The influence of machining parameters, e.g. cutting speed, feed and depth of cut on the cutting force has been investigated. The influence of the length of machining. And cutting time on the tool wear and the influence of various machining parameters, e.g. cutting speed, feed, depth of cut on the surface finish criteria has been analyzed through the various graphical representations. The combined effect of cutting speed and feed on the flank wear has also been investigated. The influence of cutting speed, feed and depth of cut on the tool wears and built up edge is analyzed graphically. The job surface condition and wear of the cutting tool edge for the different sets of experiments have been examined and compared for searching out the suitable cutting condition for effective machining performance during turning of Al/SiC-MMC. Test results show that no built-up edge is formed during machining of Al/SiC-MMC at high speed and low depth of cut. From the test results and different SEM micrographs, suitable range of cutting speed feed and depth of cut can be selected for proper machining of Al/SiC-MMC.Keywords ：Al/SiC-MMC .Cutting force .fixed rhombic tooling .Surface finish .Tool wear.1 IntroductionThere have been tremendous since the Second World War. strides in engineering Metallurgists from the materials and nuclear industries have developed a large range of super alloy and heat resistance materials mnemonics like ceramics and composite materials. With the vast and rapid progress in science and technology, modern industry has introduced a new generation of composite materials having low density and very light weight with high strength, hardness and stiffness to meet the current needs of modern technology and the challenges against liberalization and global competitiveness in market. Despite superior physical and mechanical properties, particulate reinforced metal matrix composites (PRMMCs) are not widely used in industry because of their poor machine ability. PRMMCs are extremely difficult to machine effectively using traditional machining processes because of severe tool wear due to the presence of hard SiC reinforced particle in the Al/SiC-metal matrix composite. However, modern industries have developed an increasing demand for machining advanced composite materials like Al/SiC-MMC irrespective of their hardness, toughness, configurationally complexity, microstructure, electrical conductivity, etc., for developing highly sophisticated products so as to achieve various requirements of those products such as wear resistance, low weight, high precision, high speed, etc. Advanced Al/SiC-metal matrix composites are gradually becoming very important materials for their scope of uses in manufacturing industries mainly aerospace, defense and automobile industries. The aluminum alloy reinforced with discontinuous ceramic reinforcements is rapidly replacing conventional materials in various automotive, aerospace and automobile industries:[1]. But Al/SiC-MMC machining is one of the major problems that is preventing its wide spread engineering application[2]. from some early conventional turning tests on Al/SiC-MMCs[3-5].it is found that the tool wear is excessive and surface finish is very poor when carbide tools are used for machining. During machining of Al/SiC-MMC use of coolant increases tool wear and as well as produces very poor surface finish[6]. The hard SiC particles of Al/SiC一MMC, which intermittently come into contact with the cutting tool, act as small cutting edges like those of a grinding wheel on the cutting tool edge which in due course is worn out by abrasion and resulting in formation of poor surface finish during turning[7]. When the Al/SiC-MMC job slides over a hard cutting tool edge during turning it always presents a newly formed surface to the same portion of the cutting edge and consequently due to friction, high temperature and pressure the particles of the Al/SiC-MMC adhere to the cutting tool edge. This way more particles will join up with those already adhering and the so-called built up edge is formed and if this process is continued for some time, it appears like it was nibbled away on the turned surface and produces very poor surface finish during turning.[8]. Hence, cost-effective machining with the genera on of good surface finish on the Al/SiC一MMC jobs during turning operation is a challenge to manufacturingengengineers in practice.In view of these above mentioned machining problems, the main objectives of the paper is to study the influence of different cutting parameters, e.g. cutting speed, feed, and depth of cut on the mache inability characteristics, e.g. cutting forces, surface finish, tool wear and built-up edge formation during the turning of Al/SiC-MMC. The work piece surface condition, tool wear and cutting forces for different sets of experiments have been examined and compared for searching out the suitable cutting condition through highlighting the drawbacks and suggesting appropriate measures to be undertaken during machining performance, which may overcome the machining barriers from A1/SiC一MMC. Suitability of the especially designed uncoated carbide tool is investigated during machining of Al/SiC-MMC for fulfilling various factors related to the mach inability. Test results are analyzed for achieving better machining performance during machining of Al/SiC-MMC.2 Planning for experimentationDiscontinuous particulate reinforced aluminium-SiC metal matrix composite bars of 80 mm in diameter is used for experimentation. Table 1 shows the chemical composition ofA1/SiC一MMC used for the experiments. The physical and mechanical properties of Al/SiC一MMC used for the experimental investigation are listed in Table 2. Figure 1 shows the microstructure of the LM6Mg15SiC-Al-metal matrix composite as caster with average particle size (APS) 0.000023 m. The different sets of experiments were performed using a combination trestle the. Details of the cutting tool used in the experiments and condition of machining are listed in Tables 3 and 4, respectively. The cutting forces (Px and Py) were measured using a Kistler9257B Piezoelectric Dynamometer with a Kistler5501 load amplifier during turning of Al/SiC-MMC The cutting tool wears and built-up edges were measured using a Mitutoyo Shop Microscopewith 30-times magnification and 1um resolution. Machined surfaces were measured by Taylor-Hobson Surtronic3P-type surface roughness measuring instrument. The average value of flank wear was determined from the maximum flank wear and minimum flank wear f91.3 Test results and discussionThe influence of cutting speed on the feed force (Px ) and cutting force (Pz) during turning of Al/SiC一MMC without use of coolant is represented in Fig.2. Experimental results showed that the feed force (Px) in the direction of the tool travel was higher at low cutting speed and comparatively lower at high cutting speed. From the cutting speed verses cutting force components graph, it can be concluded that the cutting force (Pz), i.e. the main force acting in the direction of the cutting velocity vector was higher at low cutting speed as compared to the high cutting speed. From Fig. 2, it can be observed that the cutting force components Px and Pz gradually decrease by increasing cutting speed during turning of Al/SiC-MMC. It is due to the gradual decrease of formation of built-up edge by increasing cutting speed..Figure 3 shows the influence of feed rate on the feed force and cutting force during turning of Al/SiC一MMC without use of coolant. The feed rate verses force components graph shows that the feed force (Px) acting in the direction of tool travel and cutting force (PZ) acting in the direction of the cutting velocity vector increase byincreasing feed rate. From the Fig. 3 it is also observed that the feed force and cutting force both are low at low feed, i.e. 0.14 mm/rev, and both feed force and cutting force are high at high feed, i.e. 1.00 mm/rev.The influence of depth of cut on the feed force and cutting force during turning of Al/SiC一MMC without use of coolant is shown in Fig. 4. From Fig. 4, it is observed that the feed force (Px) and cutting force (Pz) both increase with the increase in depth of cut. The feed force is only 20 N for 0.25 mm depth of cut whereas the feed force is 200 N for 1.5 mm depth of cut. The test results also indicate that the cutting force is 120 N for 0.25 mm depth of cut where the cutting force is 430 N for 1.5 mm depth of cut.Figure 5 shows the influence of depth of cut on the flank wear during turning of A1/SiC一MMC without use of coolant. From Fig. 5, it can be observed that at 0.25 mm depth of cut the flank wear is 0.1 mm but when the depth of cut is doubled to 0.5 mm,it increases to 0.2 mm, i.e. flank wear doubles. Hence, from the figure it can be concluded that the depth of cut is more significant on the tool wear as compared to the feed rate at constant cutting speed condition during machining of Al/SiC一MMC.Figure 6 shows the influence of feed rate on the flank wear at different cuttingspeed during turning of the Al/SiC-MMC without use of coolant. At 60 m/min, where the feed is tripled from 0.25 mm/rev to 0.75 mm/rev, the flank wear increases marginally from 0.12 mm to 0.20 mm whereas for the same change of feed rate, when cutting speed is tripled, i.e. from 60 m/min to 180 m/min, the flank wear goes up from 0.17 mm to 0.52 mm. It is evident that cutting speeds are less susceptible to the flank wear as compared to feed rate, hence, it is better to increase the feed rates rather than increase the cutting speeds during machining of A1/SiC一MMC. From the figure it can be concluded that when feed rate is tripled the flank wear goes up 1.5 times whereas when cutting speed is tripled the flank wear goes up to 3 times at constant depth of cut and for same length of continuous turning. Hence an increment of feed rate is recommended rather than increment of cutting speed for the cost effective machining of Al/SiC-MMC. From the experimental results it can be observed that when feed rate is doubled i.e. from 0.25 to 0.5 mm/rev the flank wear goes up only 1.3 times, i.e. from 0.15 to 0.20 mm at constant 100 m/min cutting speed, 0.5 mm depth of cut and for 50 mm continuous length of turning.Figure 7 shows the influence of cutting speed on surface roughness characteristics, i.e. Ra and Rt during turning ofA1/SiC一MMC without use of coolant. The test results show that the value of both surface roughness heights Ra and Rt are low at high cutting speed and comparatively high at low cutting speed. Some times during turning, it is observed that the value of surface roughness height (Rt) is abruptly higher than the trend value. The abrupt irregularity in the values of surface roughness heights may be due to presence of a hard abrasive reinforced particle, i.e. SiC, which rolls over the machined surface during turning and pouching on the turned surface and may generate grooves on the machined surface.The influence of feed rate on surface roughness heights Ra and Rt during machining of Al/SiC-MMC without use of coolant is also represented in Fig. 8. Experimental results show that both the surface roughness heights Ra and Rt increase by increasing feed rate. From the test results it can be concluded that when feed rate is tripled, i.e. from 0.25 mm/rev to 0.75 mm/rev the value of surface roughness height Ra increases by 40% whereas when cutting speed is tripled, i.e. from 60 m/min to 180 m/min the value of surface roughness height Ra decreases by 46%. Hence, it indicates that the cutting speed and feed rate have equal influence on the surface finish if both are increased simultaneously.Figure 9 shows the influence of depth of cut on the surface roughness heights Ra and Rt during machining of Al/SiC一MMC without use of coolant. From the depth of cut verses surface finish graph, it can be observed that the increase of depth of cut decreases the quality of surface finish. The arithmetic average roughness height Ra (},m) and maximum peak to valley of surface roughness height Rt (},m) both increases with increasing depth of cut.Figure 10 shows the influence of feed rate on the formation of built-up edge (BUE) at different cutting speed during turning of A1/SiC一MMC without use of coolant. From the figure it can be observed that the BUE decreases by increasing cutting speed and feed rate. Experimental results revealed the fact that when cutting speed is tripled the height of the BUE decreases by 3 times compared to its value at low speed range and when the feed rate is tripled the height of the BUE decreases 1.4 times compared to its value at low feed rate.Figure 11 a-c show the shapes of the built-up edges during turning using special geometrically designed rhombic-shaped uncoated tungsten carbide inserts. The SEM micrograph Fig. l la shows the shapes of the BUE at lower cutting speed and feed rate (i.e. 20 m/min and 0.14 mm/rev) with 0.5 mm depthof cut and for 50 mm length of continuous turning; the height of the BUE is 1.10 mm. The SEM micrograph in Fig. 11 b shows the shapes of the BUE at medium cutting speed and feed (i.e.100 m/min and 0.50 mm/rev) with 1 mm depth of cut and for 50 mm length of continuous turning. The height of the BUE is 0.95 mm. The SEM micrograph in Fig. l lc shows the shape of the BUE at low cutting speed and lower feed rate (i.e. 40 m/min and 0.14 mm/rev) with moderate depth of cut and for 50 mm length of continuous turning. The height of the BUE is 1 mm. It is observed from the micrograph that the chance of formation of BUE is higher at lower cutting speed, feed and higher depth of cut.The experimental results revel that the selection of higher cutting speeds duringmachining may cause faster tool wear as compared to the higher cutting feeds. But this does not mean that the machining should be performed at low cutting speeds. Again, as cutting speed increases, the cutting force decreases and cutting edges of tool material may break due to the high cutting force during turning at low speed range. Again, at higher cutting speeds, say 180 m/min, 225 m/min, etc., the cutting edge temperature will be very high due to the higher cutting speed which will lead to the rapid deformation of the cutting tool edge. Therefore, cutting speed range in between 60 m/min to 150 m/min is ideal and recommended for machining operation with uncoated carbide insert where cutting forces are more or less independent on cutting speed during turning of Al/SiC一MMC.Due to the high friction and temperature between the aluminum chip matrix and the cutting tool, the chip metal welds itself to the cutting tool edge. The welded chip material further increases the friction and the friction again leads to build up the localized layer upon layer and so called built up edge is formed during turning of Al/SiC-MMC. Generally, the built-up edge is formed between the chip and the rake face of the cutting tool edge. It changes the actual rake angle, which may change the direction of chip flow. The change of actual rake angle changes the shear angle, which may directly affect the cutting force. Generally, formation of built-up edge increases actual rake angle and consequently decreases the cutting force. Where as during turn of Al/SiC一MMC, it has been observed that the built-up edge was formed at low speed and generated higher cutting force (PZ). It occurs due to the presence of harder reinforced SiC particles in the Al/SiC-MMC, which are not part of cutting at low speed by the action of the cutting tool edge. Its rolls over the cutting tool edge and plough over the machined surface, which may cause of creation of high cutting force. It is another cause of adhesive tool wear andformation of poor surface finish during turning of Al/SiC-MMC.During turning of Al/SiC-MMC, it may also be observed that when the hard SiC particle of particulate aluminum rein- forced SiC metal matrix composite come into sliding contact with the cutting tool edge, the temperature at their interface is high. If it is continuous, the condition may become right for liberation of an atom from the harder metal to diffuse into the softer Al-matrix and join together with the hard reinforced SiC particles and thereby increase the hardness and abrasiveness of the work piece minimum matrix may also defuse into the harder cutting tool and weakening the sharp edge of the cutting tool. Hence, the cutting edge of the tool is torn or sheared off and carried away with the chip during turning. It is another cause of cutting tool failure due to the diffusion wear. During steady wear phase, flank wear is caused by abrasion, whereas during the rapid wear phase, it is caused by diffusion. It can also be observed that the presence of SiC particle in the particulate aluminum metal matrix composite produced semi-continuous types of chips. The formation of discontinuous chips involve the initiation of macro cracks on the free surface of the chips results in bend formation which in turn pulled out the SiC particles causes formation of small voids on the machined surface during machining. This is also one of the causes for producing poor surface finish during machining of Al/SiC-MMC.During continuous turning of Al/SiC-MMC, sometimes it may be observed that the magnitude of the cutting force (PZ) acting in the direction of cutting velocity vector is fluctuating to the maximum largest value, which may create mechanical impact. The mechanical impact may be caused by the harder reinforced SiC particles present in the work piece. Fluctuation of cutting force with sufficient large magnitude may deform the cutting edge of the tool and may damage the cuttingtool sharp edge in. Consequently, the contrary atoms from the softer alum- the form of small chips during machining of Al/SiC-MMC is another cause of flank wear.4 ConclusionsBased on the performance and test results of the various set of experiments performed for analyzing the influence of different machining parameters on the machine ability of Al/SiC-MMC utilizing fixed rhombic tooling, i.e. CCGX-09-T3-04 Al-H 10 type inserts during turning of Al/SiC-MMC without use of coolant, the following points can be made: (i) The flank wear rate is high at low cutting speed due to the generation of high cutting forces and formation of built-up edge during machining of Al/SiC一MMC. Again, when material is machining at high cutting speed, the cutting edge temperature is very high, which will also lead to rapid deformation of the cutting tool edge and in turn causes of rapid tool wear. Hence cutting speed zone between 60 m/min to 150 m/min is recommended for machining of Al/SiC-MMC, where cutting forces are more or less independent of cutting speed.(ii) From the combined effect of speed and feed on the flank wear, it can beconcluded that the feed is less sensitive to the flank wear as compared to the cutting speed. Hence, increment of feed rate is recommended rather than increment of the cutting speed for achieving higher metal removal rate at low cost during machining of Al/SiC-MMC.(iii) The cutting speed, feed and depth of cut are having equal influence on the surface roughness characteristics, i.e. Ra and Rt. High speed, low feed rate and low depth of cut are recommended for achieving better surface finish during turning of A1/SiC一MMC using CCGX-09-T3-04-A1-H 10 type insert.(iv) The generation of built-up edge during machining of A1/SiC一MMC at low cutting speed increase the actual rake angle and it is found to correlate with the increment of cutting forces, which may in turn increase the cutting tool wear.Effective machining of Al/SiC-MMC is a challenge to the manufacturing industries, which mainly restricts the wide spread application of this advance metal matrix composite in practice. The fixed rhombic tooling of CCGX-09-T3-04-A1-H10 type insert can be effectively used for proper machining of 1/SiC一MMC. The practical research analysis and test results on the machine ability of Al/SiC-MMC will provide effective guide lines to the present day manufacturing engineers. Through various highlights, the drawbacks and merits of the influence of different process parameters for achieving suitable control over the machining performance and accuracy criteria can be well understood. The research work findings will also provide useful economic machining solution by utilizing fixed rhombic tooling during processing of Al/SiC-MMC, which is otherwise usually machined by costly Polycrystalline Diamond (PCD) tools. During processing of Al/SiC-MMC, which is otherwise usually中文翻译：加工参数对颗粒增强金属碳化硅铝基复合材料切削性能的影响摘要本文介绍了碳硅化合颗粒铝基复合材料切削性的试验研究结果，在车削过程中使用菱形未涂层碳化物刀具。

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外文资料原文High Productivity —A Question of Shearer LoaderCutting SequencesK. Nienhaus, A. K. Bayer & H. Haut, Aachen University ofTechnology, GERR ecent l y, t he focus in underground longwal l coal mi ni ng has been on i ncreasi ng t he inst al l ed m ot or power of s hearer loaders and armoured face conve yors (AFC), m ore sophi st i cat ed support cont rol s yst em s and l onger face l engt h, in or der to reduce cos ts and achi eve hi gher producti vi t y. These efforts have res ul t ed i n hi ghe r out put and previ ousl y uns een face advance rat es. The t rend t owards“bi gger and bet t er” equi pm ent and l a yout schem es, however, i s rapi dl y neari ng the li mi t at i ons of t echni cal and economi cal feasi bi li t y.To reali se furt her producti vi t y i ncre as es, organi sat ional changes of l ongwall m i ni ng procedures l ooks l ike the onl y r easonabl e ans wer. The benefit s of opt i-m is ed s hearer loader cutt i ng sequences, l eadi ng t o bett er perform ance, are di s cus sed i n t hi s paper.IntroductionsTradi ti onal l y, i n underground l ongwal l m i ni ng operati ons, s hearerloaders produce coal usi ng ei ther one of t he fol lowi ng cutt ings equences: uni-di recti onal or bi-di recti onal c ycl es. Besi des t hesepre-domi nant m ethods, al t ernat i ve mi ni ng c ycl es have al so beendevel oped and s uccessfull y appli ed in underground hard coal mi nes al l over t he worl d. The hal f-web cut ti ng c ycl e as e.g. uti liz ed i n R AG Coal Int ernati onal’s Twent ym i l e Mine in Colorado, US A, and t he“Opt i-C ycl e” of M atl a’s S out h Afri can short wal l operati on m ust bem enti oned i n t hi s cont ext. Ot her mi nes have al so t est ed s i mi l ar but modi fi ed cut ti ng c ycl es res ul ti ng i n i m proved out put, e.g.im provem ent s i n t erms of product iv-it y i ncreas es of up to 40 % are thought possi bl e。

Whereas t he m enti oned mi nes are appl yi n g t he al t ernat i ve cut ti ng m et hods accordi ng to thei r spe-ci fi c condi ti ons, –e.g. s eam hei ght or equi pm ent used, –t hi s paper looks s ys t em at i call y at t he di ffer-entm et hods from a generali s ed poi nt of vi ew. A det ail ed des cripti on of t he mi ni ng c ycl e for ea ch cut ti ng t echni que, i ncluding t he i ll us t rati on of producti ve and non-prod ucti ve c ycl e ti m es, wi ll be foll owed b y a bri ef present ati on of t he perform ed product i on capacit y cal cul ati on and a summ ar y of t he t echni cal res t ri ct ions of each s ys t em. S t andardi sed equi pm ent cl as ses for di fferent seam hei ghts are defined, aft er the m ostsuit abl e and most producti ve mi ni ng e qui pm ent for each cl as s ares e-l ect ed. Bes i des t he t echni cal param e t ers of t he s hearer l oader and the AFC, t he l engt h of t he l ong-wal l face and t he speci fi c cut ti ng energ y of t he coal are t he m ai n vari abl es for each hei ght cl as s i n t he model. As a resul t of t he capaci t y cal cul ati ons, the di ffer ent shearer cut ti ng m et hods ca n be graphi call y co mpared in a st andardi s ed wa y showing t he producti vi t y of each m ethod. Due t o the gene ral char-act er of t he m odel, pot enti al opt im i s at i ons (res ul ti ng from changes i n t hecut ti ng c ycl e and t he benefi ts in t erm s of hi gher producti vit y of themi ni ng operati on) can be derived.State-of-the-art of shearer loader cutting sequences The quest i on “Why are di fferent cut ti ng s equences appli ed i n longwal l mi ni ng?” has to be an-s wered, before di s cuss ing t he si gni fi cant charact eristi cs i n t erm s of operat ional procedures. The m aj or const rai nt s and reas ons for or agai nst a s peci al cutt ing m et hod are the seam hei ght and hard-ness of t he coal, t he geot echni cal param et ers of the coal seam and t he geol ogi cal s ett ing of the mi ne infl uenci ng t he ca vi ng properti es as well as t he s ubsi dence and especi all y t he l engt h of t he l ongwal l fa ce. For each mi ning envi ronm ent the appl i cat i on of eit her s equence result s i n di fferent product ion rat es and consequentl y a dvance rat es of t he face. The coal fl ow ont o t he AFCis anot her poi nt t hat vari es l ike the l oads on the shearer loader, especi all y t he rangi ng arm s and t he st ress es and t he wear on t he pi cks.A thorough anal ys i s is neces sar y t o choos e t he bes t-suit ed mi ni ng c ycl e; therefore, general sol ut ions do not guarant ee opti m al effi ci enc y and producti vi t y.A cat egoriz at ion of shearer loader cut ti ng s equences is real ised b y four m aj or param et ers . Fi rst l y, one can s eparat e bet ween mi ni ng m et hods, whi ch m ine coal i n t wo di rect ions – m eani ng from t he head t o the t ai l gat e and on t he ret urn run as well–or i n one di recti on onl y. Secondl y, t he wa y the m i ni ng s equenc e deal s wit h t he s it uat i on at the face ends, t o advance face l i ne aft er ext ract-ing t he equi val ent of a cut ti ng web, is a charact eris ti c param et er for each separat e m ethod. The nec-essar y t ravel di st ance whil e sumpi ng vari es bet ween t he s equences, as does t he t i m e needed t o per-form t hi s t ask, t oo. Anot her as pect defi ning t he sequences i s the proport ion of t he web cut ti ng coal per run. Whereas t radit ional l y t he ful l web was us ed, t he i nt roduct i on of m odern AFC and roof s up-port autom at i on cont rol s ys t em s al l ows for effi ci ent operat i ons usi ng hal f web m et hods. The fort h param et e r i denti f yi ng st at e of the art s hearer l oader cut ti ng s equences is t he openi ng creat ed per run. Other than t he parti al or hal f-openi ng m et hod l i ke t hos e us edin Matl a’s “Opt i-C ycl e”, t he cut ti ng hei ght i s equal to the com pl et e s eam hei ght i ncl udi ng parti ngs and s oft hangi ng or foot wall m at eri al.Bi-directional cutting sequenceThe bi-directional cutting sequence, depicted in Figure 1a, is characterised by two sumping opera-tions at the face ends in a complete cycle, which is accomplished during both the forward and return trip. The whole longwall face advances each complete cycle at the equivalent of two web distances by the completion of each cycle. The leading drum of the shearer cuts the upper part of the seam while the rear drum cuts the bottom coal and cleans the floor coal. The main disadvantages of this cutting method are thought to be the unproductive time resulting from the face end activities and the complex operation. Therefore, the trend in recent years was to increase face length to reduce the relative impact of sumping in favour of longer production time.外文资料译文Uni-directional cutting sequenceIn contrast to the bi-directional method, the shearer loader cuts the coal in one single direction when in uni-directional mode. On the return trip, the floor coal is loaded and the floor itself cleaned. The shearer haulage speeds on the return trips are restricted only by the operators’ movement through the longwall face, or the haulage motors in a fully automated operation. The sumping procedure st arts in near the head gate, as shown in Figure 1b. The low machine utilisation because of cutting just one web per cycle is the main disadvantage of the uni-directional cutting sequence. Besides the coal flow can be quite irregular depending on the position of the shearer in the cycle.Half web cutting sequenceThe main benefit of half web cutting sequences is the reduction of unproductive times in the mining cycle, which results in high machine utilisation. This is achieved by cutting only a half web in m id face with bi-directional gate sequences as shown in Figure 2a. The full web is mined at the face ends, with lower speeds allowing faster shearer operation in both directions in mid seam. Beside the realisation of higher haulage speeds, the coal flow on the A FC is more balanced for shea r e r loader trips in both directions.Half-/partial-opening cutting sequenceThe advantage of the half- or, more precisely, partial- opening cutting sequence is the fact that the face is extracted in two passes. Figure 2b shows that the upper and middle part of the seam is cut during the pass towards the tailgate. Whereas the last part of this trip for the equivalent of a ma-chine length the leading drum is raised to cut the roof to allow the roof support to be advanced. On t he return trip the bottom coal is mined with the advantage of a free face and a smaller proportion of the leading drum cutting coal; consequently leading to less restrictions of the haulage speed due to the specific cutting energy of the material. The shea rer sumps in mid seam near the head gate to the full web without invoking unproductive cycle time. Like for the trip the tailgate the leading drum has to be lowered a machine length ahead ofthe main gate.Production capacity calculationsA theoretical comparison of the productivity between different mining methods in general, or in this case between different shearer loader cutting cycles, is always based on numerous assumptions and technical and geological restrictions. As a result, this production capacit y calculation does not claim to offer exact results, although it does indicate productivity trends and certain parameters for each analysed method.The model works with so-called height classes varying the seam thicknesses between 2m and 5m in steps of 50cm. Equipment is assigned to each class, having been selected by looking at the best-suited technical properties available on the market [4]. Apart from the defined equipment, it is assumed that the seam is flat and no undulations or geological faults oc cur. In the model, the ventilation and the roof support system represent no restrictions to the production. Since the aim of this model is to show ways to further increases in longwall productivity, the calculation is based on a fully automated system with no manual operators required at the face. The haulage speed of the shearer is therefore only restricted by the AFC capacity, the cutting motors and the haulage motors respectivel y.The variable parameters in this comparison of the four cutting sequences are, (besides seam thick-ness) the specific cutting energy of the coal to be cut and the length of the longwall face. The former varying between 0.2 and 0.4kWh/m³, the latter between 100m and 400m in 50m intervals. The 100m shortwalls were deliberately sel ected, since they are coming more into focus for various reasons. Geotechnical aspects, like e.g. the caving ability of the hanging wall and faults, restrict long-wall panels in many places to maximum face lengths of 150m or less, like in South Africa and Great Britain. For this reason, a detailed analysis of the potential of such longwalls is deemed appropriate.ConclusionsIn recent years much effort has been put into the optimisation of longwall operations to increase productivity and efficiency. In many cases the emphasis of these improvements was mainly focused on the equipment, e.g. increased motor power or larger dimensions of AFC’s. The organisational aspect has sometimes been neglected or did not rank as high on the agenda as other topics. In this paper, it has been demonstrated that the selected mining method has a significant impact on the achievable productivity.In a theoretical model four cutting sequences have been compared to each other while varying seam thickness, face length and coa l properties in terms of specific cutting energy.For each seam or height class a defined set of equipment was usedwith consistent restraints. Though each mine is unique, some general conclusions can be drawn anal ysing the capacit y model. Under the restrictions of the model the half web cutting sequence offers the highest output of all anal ysed methods fol-lowed by the half-opening mode. Depending on the face length, the bi-directional cutting method has advantages compared to the uni-directional sequence in terms of higher productivity.外文资料译文高效生产—一个关于采煤机截割的次序的问题目前, 地面下长壁采煤法致力于增加安装在采煤机和甲板输送机的电机功率, 以及更先进的支架控制系统和增加工作面长度,以达到减少费用和取得较高的生产效率的目的。