外文翻译
外文翻译 - 英文
The smart gridSmart grid is the grid intelligent (electric power), also known as the "grid" 2.0, it is based on the integration, high-speed bidirectional communication network, on the basis of through the use of advanced sensor and measuring technology, advanced equipme nt technology, the advancedcontrol method, and the application of advanced technology of decision support system, realize the power grid reliability, security, economic, efficient, environmental friendly and use the security target, its main features include self-healing, incentives and include user, against attacks, provide meet user requirements of power quality in the 21st century, allow all sorts of different power generation in the form of access, start the electric power market and asset optimizatio n run efficiently.The U.S. department of energy (doe) "the Grid of 2030" : a fully automated power transmission network, able to monitor and control each user and power Grid nodes, guarantee from power plants to end users among all the nodes in the whole process of transmission and distribution of information and energy bi-directional flow.China iot alliance between colleges: smart grid is made up of many parts, can be divided into:intelligent substation, intelligent power distribution network, intelli gent watt-hourmeter,intelligent interactive terminals, intelligent scheduling, smart appliances, intelligent building electricity, smart city power grid, smart power generation system, the new type of energy storage system.Now a part of it to do a simple i ntroduction. European technology BBS: an integration of all users connected to the power grid all the behavior of the power transmission network, to provide sustained and effective economic and security of power.Chinese academy of sciences, institute of electrical: smart grid is including all kinds of power generation equipment, power transmission and distribution network, power equipment and storage equipment, on the basis of the physical power grid will be modern advanced sensor measurement technology, network technology, communicationtechnology, computing technology, automationand intelligent control technology and physical grid highly integrated to form a new type of power grid, it can realize the observable (all the state of the equipment can monitor grid), can be controlled (able to control the power grid all the state of the equipment), fully automated (adaptive and self-healing) and system integrated optimization balance (power generation, transmission and distribution, and the optimization of the balance between electricity), so that the power system is more clean, efficient, safe and reliable.American electric power research institute: IntelliGrid is a composed of numerous automation system of power transmission and distribution power system, in a coordinated, effective and reliable way to achieve all of the power grid operation: have self-healing function;Rapid response to the electric power market and enterprise business requirements;Intelligent communication architecture, realizes the real-time, security, and flexible information flow, to provide users with reliable, economic power services. State grid electric power research institute, China: on the basis of the physical power grid (China's smart grid is based on high voltage network backbone network frame, different grid voltage level based on the coordinated development of strong power grid), the modern advanced sensor measurement technology, communication technology, information technology, computer technology and control technology and the physical power grid highly integrated to form a new type of power grid.It to fully meet user demand for electricity and optimize the allocation of resources, guarantee the safety, reliability and economy of power supply, meet environmental constraints, ens ure the quality of electric energy, to adapt to the development of power market, for the purpose of implementing the user reliable, economic, clean and interactive power supply and value-added services.BackgroundStrong smart grid development in the wor ld is still in its infancy, without a common precisely defined, its technology can be roughly divided into four areas: advanced Measurement system, advanced distribution operation, advanced transmission operation and advanced asset management.Advanced meas urement system main function is authorized to the user, make the system to establish a connection with load, enabling users to support the operationof the power grid;Advanced core distribution operation is an online real-time decision command, goal is to disaster prevention and control, realizing large cascading failure prevention;Advanced transmission operation main role is to emphasize congestion ma nagement and reduce the risk of the large-scale railway;Advanced asset management is installed in the system can provide the system parameters and equipments (assets) "health" condition of advanced sensor, and thereal-time information collected by integrat ion and resource management, modeling and simulation process, improve the operation and efficiency of power grid.The smart grid is an important application of Internet of things, and published in the journal of computer smart grid information system archit ecture research is carried on the detailed discussion on this, and the architecture of the smart grid information system are analyzed.The market shareThe establishment of the smart grid is a huge historical works.At present many complicated smart grid project is underway, but the gap is still great.For the provider of the smart grid technology, promote the development of facing the challenges of the distribution network system i s upgrading, automation and power distribution substation transportation, smart grid network and intelligent instruments.According to the latest report of parker investigators, smart grid technology market will increase from $2012 in 33 billion to $2020 in 73 billion, eight years, the market accumulated up to $494 billion.China smart grid industry market foresight and investment forward-looking strategic planning analysis, points out that in our country will be built during the "twelfth five-year""three vertical and three horizontal and one ring" of uhv ac lines, and 11 back to u hv dc transmission project construction, investment of 300 billion yuan.Although during the period of "much starker choices-and graver consequences-in" investment slowed slightly, the investment is 250 billion yuan.By 2015, a wide range of national power grid, long distance transmission capacity will reach 250 million kilowatts, power transmission of 1.15 trillion KWH per year, to support the new 145 million kilowatts of clean energy generation given and sent out, can satisfy the demand of morethan 1 million electric cars, a grid resource configuration optimization ability, economic efficiency, safety and intelligent levels will be fully promoted.The abroad application of analysisIn terms of power grid development foundation, national electricity dema nd tends to be saturated, the grid after years of rapid development, architecture tends to be stable, mature, have a more abundant supply of electric power transmission and distribution capacity.Germany has "E - Energy plan, a total investment of 140 million euros, from 2009 to 2012, four years, six sites across the country to the smart grid demonstration experiment.At the same time also for wind power and electric car empirical experiments, testing and management of power consumption of the Internet.Big companies such as Germany's Siemens, SAP and Swiss ABB are involved in this plan.To smart grid Siemens 2014 annual market scale will reach 30 billion euros, and plans to take a 20% market share, make sure order for 6 billion euros a year.The advanced nat ureCompared with the existing grid, smart grid, reflects the power flow, information flow and business flow marked characteristics of highly integration, its advancement and advantage mainly displays in:(1) has a strong foundation of grid system and te chnical support system, able to withstand all kinds of external disturbance and attacks, can adapt to large-scale clean energy and renewable energy access, strong sex of grid reinforced and ascend.(2) the information technology, sensor technology, automatic control technology organic combination with power grid infrastructure, a panoramic view of available power grid information, timely detection, foresee the possibility of failure.Fault occurs, the grid can be quickly isolate fault,realize self recovery,to avoid the occurrence of blackouts.(3) flexible ac/dc transmission, mesh factory coordination, intelligent scheduling, power storage, and distribution automation technology widespread application, makes the control of power grid operation more flexibl e,economic, and can adapt to a large number of distributed power supply, power grid and electric vehicle charging and discharging facility access.(4) communication, information, and the integrated use of modern management technology, will greatly improve the efficiency of power equipment, and reduce the loss of electrical power, making the operation of power grid is more economic and efficient.(5) the height of the real-time and non real-time information integration, sharing and utilization, to run the show management comprehensive, complete and fine grid operation state diagram, at the same time can provide decision support, control scheme and the corresponding response plans.(6) to establish a two-way interactive service mode, users can real-time understand the status of the power supply ability, power quality, price and power outage information, reasonable arrangement of electric equipment use;The electric power enterprise can obtain the user's electricity information in detail, to provide more value-added services.developmentaltrend"Twelfth five-year" period, the state grid will invest 500 billion yuan to build the connection of large ene rgy base and center of the "three horizontal three longitudinal" main load of ultra high voltage backbone network frame and 13 back to long branch, engineering, to form the core of the world first-class strong smart grid."Strong smart grid technology standards promulgated by the state grid system planning", has been clear about the strong smart grid technology standards roadmap, is the world's first used to guide the development of smart grid technology guiding standards.SGC planning is to built 2015 basic information, automation, interaction characteristics of strong smart grid, formed in north China, central China, east China, for the end to the northwest and northeast power grid for sending the three synchronous power grid, the grid resource allocati on ability, economic efficiency and safety level, technology level and improve intelligent level.(1) the smart grid is the inevitable developing trend ofpower grid technology.Such as communication, computer, automation technology has extensive applicati on in the power grid, and organic combination with traditional electric power technology, and greatly improve the intelligent level of the power grid.Sensor technology and information technology application in the power grid, the system state analysis and auxiliary decision provides the technical support, make it possible to grid self-healing.Scheduling technology, automation technology and the mature development of flexible transmission technology, for the development and utilization of renewable energy an d distributed power supply provides the basic guarantee.The improvement of the communication network and the popularization and application of user information collection technology, promote the two-way interaction with users of the grid.With the further development of various new technologies, application and highly integrated with the physical power grid, smart grid arises at the historic moment.(2) the development of smart grid is the inevitable choice of social and economic development.In order to ach ieve the development of clean energy, transport and given power grid must increase its flexibility and compatibility.To withstand the increasingly frequent natural disasters and interference, intelligent power grid must rely on means to improve its securit y defense andself-healing ability.In order to reduce operating costs, promote energy conservation and emissions reduction, power grid operation must be more economic and efficient, at the same time must to intelligent control of electric equipment, reduce electricity consumption as much as possible.Distributed generation and energy storage technology and the rapid development of electric cars, has changed the traditional mode of power supply, led power flow, information flow, business flow constantly fusion, in order to satisfy the demands of increasingly diverse users.PlanJapan plans to all the popularity of smart grid in 2030, officer of the people at the same time to promote the construction of overseas integrated smart grid.In the field of battery, Japanese firms' global market share goal is to strive to reach 50%, with about 10 trillion yen in the market.Japan's trade ministry has set up a "about the next generation of energy systems international standardizationresearch institute", the japan-american established in Okinawa and Hawaii for smart grid experimental project [6].Learns in the itu, in 2020 China will be built in high power grid with north China, east China, China as the center, northeast, northwest 750 kv uhv power grid as the sending, connecting each big coal base, large hydropower bases, big base for nuclear power, renewable energy base, the coordinated development of various grid strong smart grid.In north China, east China, China high voltage synchronous ZhuWangJia six "five longitudi nal and transverse" grid formation.The direction ofIn the green energy saving consciousness, driven by the smart grid to become the world's countries to develop a focus areas.The smart grid is the electric power network, is a self-healing, let consum ers to actively participate in, can recover from attacks and natural disasters in time, to accommodate all power generation and energy storage, can accept the new product, service and market, optimize asset utilization and operation efficiency, provide qua lity of power supply for digital economy.Smart grid based on integrated, high-speed bidirectional communication network foundation, aims to use advanced sensor and measuring technology, advanced equipment, technology and advanced control methods, and adv anced technology of decision support system, realize the power grid reliability, security, economic, efficient, environmental friendly, and the use of safe run efficiently.Its development is a gradual progressive evolution, is a radical change, is the product of the coordinated development of new and existing technologies, in ad dition to the network and smart meters also included the wider range.Grid construction in high voltage network backbone network frame, all levels of the coordinated development, informatization, automation, interaction into the characteristics of strong smart grid, improve network security, economy, adaptability and interactivity, strength is the foundation, intelligence is the key.meaningIts significance is embodied in the foll owing aspects:(1) has the strong ability of resources optimization allocation.After the completion of the smart grid in China, will implement the big water and electricity, coal, nuclear power, large-scale renewable energy across regions, long distance, large capacity, low loss, high efficiency, regional power exchange capacity improved significantly.(2) have a higher level of safe and stable operation.Grid stability and power supply reliability will be improved, the safety of the power grid close coord ination between all levels of line, have theability to against sudden events and serious fault, can effectively avoid the happening of a wide range of chain failure, improve power supply reliability, reduce the power loss.(3) to adapt and promote the dev elopment of clean energy.Grid will have wind turbines power prediction and dynamic modeling, low voltage across, and active reactive power control and regular units quickly adjust control mechanism, combined with the application of large capacity storage technology, the operation control of the clean energy interconnection capacity will significantly increased, and make clean energy the more economical, efficient and reliable way of energy supply.(4)implementing highly intelligent power grid scheduling.Co mpleted vertical integration, horizontal well versed in the smart grid scheduling technology support system, realize the grid online intelligent analysis, early warning and decision-making, and all kinds of new transmission technology and equipment of effi cient control and lean control of ac/dc hybrid power grid.(5)can satisfy the demands of electric cars and other new type electric power user services.Would be a perfect electric vehicle charging and discharging supporting infrastructure network, can meet the needs of the development of the electric car industry, to meet the needs of users, realize high interaction of electric vehicles and power grid.(6) realize high utilization and whole grid assets life cycle management.Can realize electric grid system of the whole life cycle management plan.Through smart grid scheduling and demand side management, power grid assets utilization hours, power grid assets efficiency improvedsignificantly.(7) to realize power convenient interaction between the user and the grid.Will form a smart electricity interactive platform, improving the demand side management, to provide users with high-quality electric power service.At the same time, the comprehensive utilization of the grid can be distributed power supply, intelli gent watt-hour meter, time-sharing electricity price policy and the electric vehicle charging and discharging mechanism, effectively balance electric load, reduce the peak valley load difference, reduce the power grid and power construction costs.(8)grid management informatization and the lean.Covering power grid will each link of communication network system, realize the power grid operation maintenance integrated regulation, data management, information grid spatial information services, and production and scheduling application integration, and other functions, to realize all-sided management informatization and the lean.(9) grid infrastructure of value-added service potential into full play.In power at the same time, the national strategy of "triple play" of services, to provide users with community advertising, network television, voice and other integrated services, such as water supply, heating, gas industry informatization, interactive platform support, expand the range of value-added services and improve the grid infrastructure and capacity, vigorously promote the development of smart city.(10)Gridto promote the rapid development of related industries.Electric power industry belongsto the capital-intensive and technology-intensive industry, has the characteristics of huge investment, long industrial chain.Construction of smart grid, which is beneficial to promote equipment manufacturing information and communication industry technology upgrade, for our country to occupy the high ground to lay the foundation in the field of electric power equipment manufacturing.Important significanceLife is convenientThe construction of strong smart grid, will promote the development of intelligent community, smart city, improve people's quality of life.(1) to make life more convenient.Home intelligent power system can not onlyrealize the real-time control of intelligent home appliances such as air conditioning, water heater and remote control;And can provide telecommunication network, Internet, radio and television network access services;Through intelligent watt-hour meter will also be able to achieve au tomatic meter reading and automatic transfer fee, and other functions.(2) to make life more low carbon.Smart grid can access to the small family unit such as wind power and photovoltaic roof, pushing forward the large-scale application of electric cars, so as to raise the proportion of clean energy consumption, reduce the pollution of the city.(3) to make life more economical.The smart grid can promote power user role transformation, both electricity and sell electricity twofold properties;To build a family for the user electricity integrated services platform, to help users choose the way of electricity, save energy, reduce the energy expense.Produce benefitThe development of a strong smart grid, the grid function gradually extended to promote the optim al allocation of energy resources, guarantee the safe and stable operation of power system, providing multiple open power service, promote the development of strategic emerging industries, and many other aspects.As China's important energy delivery and configuration platform, strong and smart grid from the investment construction to the operation of production process will be for the national economic development, energy production and use, environmental protection bring great benefits.(1)in power system.Can save system effective capacity;Reducing the system total power generation fuel cost;Improving the efficiency of grid equipment, reduce construction investment;Ascension grid transmission efficiency, reduce the line loss.(2)in terms of power customers.Can realize the bidirectional interaction, to provide convenient services;Improving terminal energy efficiency, save power consumption;To improve power supply reliability, and improve power quality.(3) in the aspect of energy saving and environment.Can improve the efficiency of energy utilization, energy conservation and emissions reduction benefit.To promote clean energy development, realize the alternative reductionbenefits;Promote the overall utilization of land resources, saving land usage.(4) other aspects.Can promote the economic development, jobs;To ensure the safety of energy supply;Coal for power transmission and improve the efficiency of energy conversion, reducing the transportation pressure.Propulsion system(1) can effectively improve t he security of power system and power supply e of strong smart grid "self-healing" function, can accurately and quickly isolate the fault components, and in the case of less manual intervention make the system quickly returned to normal, so as to improve the security and reliability of power supply system.(2) the power grid to realize the sustainable development.Strong smart grid technology innovation can promote the power grid construction, implementation technology, equipment, operation an d management of all aspects of ascension, to adapt to the electric power market demand, promote the scientific and sustainable development of power grid.(3) reduce the effective ing the power load characteristics in different regions of the ch aracteristics of big differences through the unification of the intelligent dispatching, the peakand peak shaving, such as networking benefit;At the same time through the time-sharing electricity price mechanism, and guide customers low power, reduce the peak load, so as to reduce the effective capacity.(4) to reduce the system power generation fuel costs.Construction of strong smart grid, which can meet the intensive development of coal base, optimization of power distribution in our country, thereby red ucing fuel transportation cost;At the same time, by reducing the peak valley load difference, can improve the efficiency of thermal power unit, reduce the coal consumption, reduce the cost.(5)improve the utilization efficiency of grid equipment.First of all, by improving the power load curve, reduce the peak valley is poor, improve the utilization efficiency of grid equipment;Second, by self diagnosis, extend the life of the grid infrastructure.(6) reduce the line loss.On the important basis of uhv transmission technology of strong smart grid, will greatly reduce the loss rate in the electric power transmission;Intelligent scheduling system, flexible transmission technology and real-time two-way interaction with customers, can optimize the tide distribut ion, reducing line loss;At the same time, the construction and application of distributed power supply, also reduce the network loss of power transmission over a long distance.Allocation of resourcesEnergy resources and energy demand in the reverse distribution in our country, more than 80% of the coal, water power and wind power resource distribution in the west, north, and more than 75% of the energy demand is concentrated in the eastern and central regions.Energy resources and energy demand unbalance d distribution of basic national conditions, demand of energy needs to be implemented nationwide resource optimizing configuration.The construction of strong smart grid, for optimal allocation of energy resources provides a good platform.Strong smart grid is completed, will form a strong structure and sending by the end of the power grid power grid, power capacity significantly strengthened, and the formation of the intensity, stiffness of uhv power transmission network, realize the big water and electricit y, coal, nuclear power, large-scale renewable energy across regions, long distance, large capacity, low loss, high efficiency transport capacity significantly increased power a wide range of energy resources optimization.Energy developmentThe development and utilization of clean energy such as wind power and solar energy to produce electricity is given priority to, in the form of the construction of strong smart grid can significantly improve the grid's ability to access, given and adjust clean energy, vigorously promote the development of clean energy.(1) smart grid, the application of advanced control technology and energy storage technology, perfect the grid-connected clean energy technology standards, improve the clean energy acceptance ability.Clean energy base, (2) the smart grid, rational planning of large-scale space truss structure and sending the power structure, application of uhv, flexible transmission technology, meet the requirements of the large-scale clean energy electricitytransmission.(3) the smart grid for large-scale intermittent clean energy to carry on the reasonable and economic operation, improve the operation performance of clean energy production.(4) intelligent with electric equipment, can achieve acceptance and coordinated cont rol of distributed energy, realize the friendly interaction with the user, the user to enjoy the advantages of new energy power.Energy conservation and emissions reductionStrong smart grid construction to promote energy conservation and emissions reduc tion,development of low carbon economy is of great significance: (1) to support large-scale clean energy unit net, accelerate the development of clean energy, promote our country the optimization of energy structure adjustment;(2) to guide users reasonable arrangement of electricity, reducing peak load, stable thermal power unit output, reduce power generation coal consumption;(3) promote ultra-high voltage, flexible transmission, promotion and application of advanced technology such as economic operation, reduce the transmission loss, improve power grid operation efficiency;(4) to realize the power grid to interact with users effectively, promote intelligent power technology, improve the efficiency of electricity;(5) to promote the electric car of large-scale application, promote the development of low-carbon economy, achieve emission reduction benefits.There are three milestones of the concept of smart grid development:The first is 2006, the United States "smart grid" put forward by the IBM solution.IBM smart grid is mainly to solve, improve reliability and safety of power grid from its release in China, the construction of the smart grid operations management innovation - the new train of thought on the development of China's power "the white paper can be seen that the scheme provides a larger framework, through to the electric power production, transmission, the optimization of all aspects of retail management, for the relevant enterprises to improve operation efficiency and reliability, reduce cost dep icts a blueprint.IBM is a marketing strategy.The second is the energy plan put forward by the Obama took office, in addition to the published plan, the United States will also focus on cost $120 billion a year circuit。
外文翻译中英文对照
Strengths优势All these private sector banks hold strong position on CRM part, they have professional, dedicated and well-trained employees.所以这些私人银行在客户管理部分都持支持态度，他们拥有专业的、细致的、训练有素的员工。
Private sector banks offer a wide range of banking and financial products and financial services to corporate and retail customers through a variety of delivery channels such as ATMs, Internet-banking, mobile-banking, etc. 私有银行通过许多传递通道（如自动取款机、网上银行、手机银行等）提供大范围的银行和金融产品、金融服务进行合作并向客户零售。
The area could be Investment management banking, life and non-life insurance, venture capital and asset management, retail loans such as home loans, personal loans, educational loans, car loans, consumer durable loans, credit cards, etc. 涉及的领域包括投资管理银行、生命和非生命保险、风险投资与资产管理、零售贷款（如家庭贷款、个人贷款、教育贷款、汽车贷款、耐用消费品贷款、信用卡等）。
Private sector banks focus on customization of products that are designed to meet the specific needs of customers. 私人银行主要致力于为一些特殊需求的客户进行设计和产品定制。
毕业论文外文翻译格式【范本模板】
因为学校对毕业论文中的外文翻译并无规定，为统一起见,特做以下要求：1、每篇字数为1500字左右，共两篇；2、每篇由两部分组成:译文+原文.3 附件中是一篇范本，具体字号、字体已标注。
外文翻译（包含原文)(宋体四号加粗）外文翻译一（宋体四号加粗）作者：(宋体小四号加粗）Kim Mee Hyun Director, Policy Research & Development Team，Korean Film Council（小四号）出处：(宋体小四号加粗)Korean Cinema from Origins to Renaissance(P358～P340) 韩国电影的发展及前景（标题：宋体四号加粗）1996～现在数量上的增长(正文:宋体小四）在过去的十年间，韩国电影经历了难以置信的增长。
上个世纪60年代，韩国电影迅速崛起，然而很快便陷入停滞状态,直到90年代以后，韩国电影又重新进入繁盛时期。
在这个时期，韩国电影在数量上并没有大幅的增长，但多部电影的观影人数达到了上千万人次。
1996年，韩国本土电影的市场占有量只有23.1%。
但是到了1998年，市场占有量增长到35。
8%，到2001年更是达到了50%。
虽然从1996年开始，韩国电影一直处在不断上升的过程中，但是直到1999年姜帝圭导演的《生死谍变》的成功才诞生了韩国电影的又一个高峰。
虽然《生死谍变》创造了韩国电影史上的最高电影票房纪录，但是1999年以后最高票房纪录几乎每年都会被刷新。
当人们都在津津乐道所谓的“韩国大片”时，2000年朴赞郁导演的《共同警备区JSA》和2001年郭暻泽导演的《朋友》均成功刷新了韩国电影最高票房纪录.2003年康佑硕导演的《实尾岛》和2004年姜帝圭导演的又一部力作《太极旗飘扬》开创了观影人数上千万人次的时代。
姜帝圭和康佑硕导演在韩国电影票房史上扮演了十分重要的角色。
从1993年的《特警冤家》到2003年的《实尾岛》，康佑硕导演了多部成功的电影。
外文翻译原文
DOI: 10.1111/j.1475-679X.2010.00367.xJournal of Accounting ResearchVol. 48 No. 2 May 2010Printed in U.S.A.Discussion ofChief Executive Officer EquityIncentives and AccountingIrregularitiesJOHN E. CORE∗1. IntroductionIn an interesting and important paper, Armstrong, Jagolinzer, and Lar-cker (AJL) re-examine the question of whether CEO equity incentives cause accounting irregularities. As the authors note, this question is already much studied in the literature with a variety of methods and samples. Broadly speaking, the prior literature hypothesizes that equity incentives cause man-agers to manipulate accounting information, and generally finds a positive relation or no relation between equity incentives and proxies for manipula-tion. AJL add to this literature a larger sample that includes smaller firms (a beginning sample of roughly 4,000 firms a year versus roughly 1,500 firmsa year used in ExecuComp). In addition, they introduce a novel method (propensity score matching) that is robust to misspecification of functional form (―overt bias‖) and that provides an assessment of correlated omitted variables bias (―hidden bias‖).In contrast to prior research that generally examines pre–Sarbanes-Oxley data (2001 and before), AJL’s sample runs from 2001 to 2005.∗ The Wharton School, University of Pennsylvania. This discussion has benefited from, andreflects the comments of, participants at the 2009 Journal of Accounting Research conference. I gratefully acknowledge helpful comments from Wayne Guay and Greg Miller, and the financial support of the Wharton School. Any errors are the sole responsibility of the author.273Copyright C, University of Chicago on behalf of the Accounting Research Center, 2010274J. E. COREUsing this later sample, AJL find no evidence of a positive relation between CEO equity incentives and their proxies for accounting irregular-ities. As proxies for accounting irregularities, they use restatements, share-holder lawsuits, and U.S. Securities and Exchange Commission Account-ing and Auditing Enforcement Releases (AAERs). Using ―partial match‖logistic regressions similar to those used by some prior researchers, AJLfind no relation between incentives and accounting manipulation. Us-ing propensity score matching, the authors generally find no relation be-tween incentives and accounting manipulation, although there is some ev-idence of a negative relation between incentives and lawsuits. However,the negative relation with lawsuits does not appear to be robust to po-tential correlated omitted variables bias. The authors note that their re-sults are similar if they examine their later accounting irregularities us-ing the sample of ExecuComp firms generally used by prior research. Finally, the authors also show results using the earlier sample used by Erickson, Hanlon, and Maydew [2006]. In a ―partial match‖ conditional lo-gistic regression, AJL find a positive relation between incentives and fraud that is consistent with Johnson, Ryan, and Tian [2009] and in contrastto Erickson, Hanlon, and Maydew [2006]. However, in the better speci-fied, full-sample propensity-score model, AJL find no relation between in-centives and accounting manipulation, consistent with the full-sample lo-gistic regression in Erickson, Hanlon, and Maydew [2006]. In summary, the propensity score method shows no relation between incentives and ac-counting irregularities in the late sample, and no relation between incen-tives and accounting irregularities in the early sample. Overall, AJL’s result s suggest no relation between incentives and accounting irregularities. These results are important in that they add to a growing body of evidence that shows that, when empirical tests are correctly specified, there is no evidence of a relation between incentives and accounting irregularities.The remainder of this discussion is as follows. In section 2, I briefly out-line the hypotheses and method of the prior literature and those of AJL. In section 3, I discuss AJL’s results. Much of the discussion in the conference was on understanding propensity-score methods and whether and to what extent these methods should be used in accounting research, and I address these issues in section 4. In the final section, I conclude.2. Summary of Prior Literature—Hypotheses and Method2.1HYPOTHESESAs noted in AJL’s introduction, the basic hypothesis in prior literature is that equity incentives motivate executives to manipulate accounting infor-mation for personal gain. For this to be the case, executives need to believe that they can increase the stock price by manipulating earnings. In addi-tion, as discussed by participants and tested by, for example, Bergstresser and Philippon [2006] and Erickson, Hanlon, and Maydew [2006], if executives are rational when they manipulate earnings in an attempt toCHIEF EXECUTIVE OFFICER EQUITY INCENTIVES275 increase the value of their holdings, they will do so when they expect tobe able to benefit by selling equity. Thus, one expects vested options andstock holdings to predict rational manipulation; it would be irrational foran executive to manipulate if all his or her options and stock holdings were unvested.Participants noted that the underlying ―more equity is worse‖ story in this literature is similar to the story in an earlier and ongoing literature that―more equity is better‖ (e.g., Morck, Shleifer, and Vishny [1988]). In boththese literatures, how results are interpreted depend crucially on whetherequity incentives are assumed to be exogenous or endogenous (Demsetzand Lehn [1985]). Equity holdings in theory are chosen by boards to max-imize firm value and by managers to maximize private value, but for the―more equity is worse‖ and ―more equity is better‖ stories to go through,these choices need to have a substantial random (exogenous) component.The ―more equity is worse‖ story is causal if there is a substantial randomcomponent to the way that boards grant and require equity ownership, andif equity ownership has gotten to be too large on average. If boards do not understand equity compensation, but continue to grant it, it is conceivablethat equity incentives are random and too large.On the other hand, there are other explanations that involve maximiz-ing, nonrandom behavior. AJL give the example of risk-aversion: CEOs withlow risk aversion may hold more incentives and may be more likely to com-mit fraud. Another is monitoring difficulty. Firms with greater monitoringdifficulty may use more incentives, but their greater monitoring difficultyallows more accounting manipulation. Another possible link is CEO power.Suppose that powerful CEOs overpay themselves using equity, and have tohold this equity to camouflage their excess pay. Then if powerful CEOs aremore likely to commit fraud, there may appear to be a link between equityincentives and fraud.Whether there are perverse effects of equity incentives is a very important question. As discussed earlier and as demonstrated by Hribar and Nichols[2007], tests using equity incentives as an independent variable appear tobe readily confounded by endogeneity and correlated omitted variablesproblems.1 Thus, techniques that readily assess the sensitivity of results tocorrelated omitted variables seem not only worthwhile but also necessary.2.2METHODPrior work tests the hypothesis that incentives cause accounting irregu-larities using versions of the following regression model:Accounting Irregularity = β X + γ Equity Incentives + ε.(1) In this model, the ―treatment‖ or variable of interest is Equity Incentives, andthe dependent variable is some type of accounting irregularity or earnings1Note that endogeneity is fundamentally a correlated omitted variables problem. If onecould observe the part of an endogenous regressor that was correlated with the error term,one could include this omitted variable, and the regression would be correctly specified.276J. E. COREmanagement, and X are controls for determinants of Accounting Irregularity and/or Equity Incentives.As illustrated in AJL’s table 1, the prior literature uses a variety of prox-ies for incentives and accounting irregularities. Dependent variables exam-ined by the prior literature include: (1) AAERs (e.g., Erickson, Hanlon, and Maydew [2006]); (2) restatements (e.g., Burns and Kedia [2006]); and (3) accruals (e.g., Begstresser and Philippon [2006]). Perhaps reflecting the uncertainty discussed earlier about how to measure incentives to manage earnings, the prior literature has used a variety of proxies for equity incen-tives including: (1) total portfolio equity incentives (e.g., Erickson, Hanlon, and Maydew [2006]); (2) vested incentives (e.g., Erickson, Hanlon, and Maydew [2006] and Burns and Kedia [2006]); and (3) option compensa-tion as a percentage of total compensation (e.g., Burns and Kedia [2006]). In addition, studies differ as to whose incentives are measured: Most stud-ies use (1) CEO incentives, but some studies (e.g., Erickson, Hanlon, and Maydew [2006], Johnson, Ryan, and Tian [2009]) use (2) incentives for the top five executives.。
外文翻译完整版
毕业设计外文资料翻译原文题目：The Design and Retorfit of Buildings for Resistance to Blast-Induced Progressive Collapse 译文题目：建筑物的设计和改造抵抗由爆炸冲击引起的建筑物的连续倒塌院系名称：土木建筑学院专业班级：土木工程0303班学生姓名：吴建明学号：20034040332指导教师：白杨教师职称：讲师附件： 1.外文资料翻译译文；2.外文原文。
指导教师评语及成绩：签名： 2010年 4月 12日附件1：外文资料翻译译文译文标题（3号黑体，居中）×××××××××（小4号宋体，1.5倍行距）×××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××××…………。
（要求不少于3000汉字）建筑物的设计和改造抵抗由爆炸冲击引起的建筑物的连续倒塌1.简介在近现代史中，极端的爆炸事件推动了现有的设计方法和规范重新评估冲击荷载对建筑结构和它们的居住着的影响。
外文翻译及中文译文
车床用于车外圆、端面和镗孔等加工的机床称作车床。
车削很少在其他种类的机床上进行，因为其他机床都不能像车床那样方便地进行车削加工。
由于车床除了用于车外圆还能用于镗孔、车端面、钻孔和铰孔，车床的多功能性可以使工件在一次定位安装中完成多种加工。
这就是在生产中普遍使用各种车床比其他种类的机床都要多的原因。
两千多年前就已经有了车床。
现代车床可以追溯到大约1797年，那时亨利•莫德斯利发明了一种具有把主轴和丝杆的车床。
这种车床可以控制工具的机械进给。
这位聪明的英国人还发明了一种把主轴和丝杆相连接的变速装置，这样就可以切削螺纹。
车床的主要部件：床身、主轴箱组件、尾架组件、拖板组、变速齿轮箱、丝杆和光杆。
床身是车床的基础件。
它通常是由经过充分正火或时效处理的灰铸铁或者球墨铸铁制成，它是一个坚固的刚性框架，所有其他主要部件都安装在床身上。
通常在球墨铸铁制成，它是一个坚固的刚性框架，所有其他主要部件都安装在床身上。
通常在床身上面有内外两组平行的导轨。
一些制造厂生产的四个导轨都采用倒“V”，而另一些制造厂则将倒“V”形导轨和平面导轨结合。
由于其他的部件要安装在导轨上并（或）在导轨上移动，导轨要经过精密加工，以保证其装配精度。
同样地，在操作中应该小心，以避免损伤导轨。
导轨上的任何误差，常常会使整个机床的精度遭到破坏。
大多数现代车床的导轨要进行表面淬火处理。
以减少磨损和擦伤，具有更大的耐磨性。
主轴箱安装在床身一端内导轨的固定位置上。
它提供动力。
使工件在各种速度下旋转。
它基本上由一个安装在精密轴承中的空心轴和一系列变速齿轮---类似于卡车变速箱所组成，通过变速齿轮，主轴可以在许多中转速的旋转。
大多数车床有8～18中转速，一般按等比级数排列。
在现代车床上只需扳动2～4个手柄，就能得到全部挡位的转速。
目前发展的趋势是通过电气的或机械的装置进行无级变速。
由于车床的精度在很大程度上取决于主轴，因此主轴的结构尺寸较大，通常安装在紧密配合的重型圆锤滚子轴承或球轴承中。
外文翻译英文原文
Executive SummaryExtracted fromNIST NCSTAR 1-4 (Draft)Federal Building and Fire Safety Investigation of the World Trade Center DisasterActive Fire Protection Systems (Draft)E XECUTIVE S UMMARYIn the event of a fire in a building, the safety of occupants and first responders and the protection of property is accomplished through a combination of passive and active means. A passive fire protection system is one which is an integral part of the building layout and materials of construction, such as partitions to confine the fire, a stairway to assist rapid evacuation, or spray-on fire proofing to increase the fire resistance of a load-bearing steel structure. Active fire protection systems are designed to come into play only when a fire is present and require activation through a combination of sensors or mechanical means. The active fire protection systems in World Trade Center (WTC) 1, 2, and 7 consisted of fire sensors and alarms, notification systems, sprinklers, water supplies, and smoke management systems. Active and passive fire protection systems work together to control the spread of the fire and maintain the integrity of the structure; however, the fire department is always relied upon to fully extinguish the fire and rescue occupants who may be immobilized.The automatic fire sprinkler systems in WTC 1, 2, and 7 were the first line of defense. Water stored in the building from public sources or pumped from fire apparatus was supplied through dedicated piping to the area of the fire. Also present in the buildings were hoses, preconnected to a water supply through standpipes located in the stairwells and other utility shafts. The standpipes provided hose connections at each floor for The Fire Department of the City of New York (FDNY). In addition, standpipe preconnected hoses were installed for trained occupants to manually suppress fires.The heart of the fire detection system was the automatic fire alarm and emergency notification system. Occupants in the building depended on this system to detect fires and provide information for emergency evacuation. Capabilities were also designed for the ventilation system to operate in a way to purge smoke produced by fires from the building. Smoke purge was intended to be used for post-fire clean-up but could be used during a fire event at the discretion of the FDNY.This report includes an examination of the design and installation of the active fire protection systems in WTC 1, 2, and 7 and a description of the normal operation of fully functional systems and their potential effect on controlling the fires on September 11, 2001. The applicable building and fire codes and standards, as well as the history of fires in these buildings, are also documented.FIRESPRIOR TO SEPTEMBER 11, 2001E.1 SIGNIFICANTSignificant fires in WTC 1, 2, and 7 prior to September 11, 2001, were of interest to the investigation, particularly those that activated multiple sprinklers or where hoses were used to suppress the fires. Because the records of fire events in the buildings maintained by The Port Authority of New York and New Jersey (PANYNJ) were destroyed in the fire and collapse of WTC 1, information available for study was limited to that from FDNY fire and investigation reports.A major fire occurring in WTC 1 in 1975, prior to the installation of sprinklers, and the bombing of the WTC towers in 1993 were the most significant incidents in the history of these buildings. In addition,47 other fires were identified that were substantial enough to activate a sprinkler or require hoses to suppress the fire. Sixteen fire incidents exercised multiple sprinklers or multiple standpipe connectedExecutive Summary Draft for Public Comment hoses (with or without the activation of at least one sprinkler). Thirty-one fires involved the use of one standpipe hose or one standpipe hose and discharge of one sprinkler. Only three fires were identified to have occurred in WTC 7 prior to 2001. The FDNY fire reports and fire investigation records obtained by the National Institute of Standards and Technology (NIST) indicate that in areas protected by automatic sprinklers, no fire activated more than three sprinklers.AND PRECONNECTED HOSE SYSTEMS E.2 SPRINKLERS,STANDPIPES,The evaluation of the sprinklers, standpipes, and preconnected hose systems was performed by subject experts at Hughes Associates, Inc., under contract to NIST. The project documented the design, installation, and operation of the fire suppression systems in WTC 1, 2, and 7; evaluated the consistency of the sprinkler and standpipe systems installations with best engineering practices; described the New York City (NYC) water supply system and evaluated the sprinkler system water supply; and estimated suppression system performance when challenged with design fire scenarios assumed in standard engineering practice as well as with a fire scenario similar to that which occurred on September 11, 2001. Major features of the fire suppression systems are documented based on a review of the available information. In addition to describing in detail the sprinkler, standpipe, and preconnected hose systems, special fire suppression systems are briefly discussed. System features documented include riser systems, zone arrangements, water tanks, pumps, fire department connections, control valves, and hose rack arrangements. Additionally, documentation of the sprinkler, standpipe, and preconnected hose system installations was examined for consistency with the applicable installation standards and state-of-the-art engineering practices at the time of system installation.A description of the NYC water supply, including sizes, locations, and directions of water mains surrounding the WTC complex and distribution system within the buildings is provided to adequately evaluate the primary source of water for the automatic sprinkler and hose systems. Adequacy of the sprinkler system water supply was based on a detailed review of the available documentation. Flow capacity and duration of water supplies to the installed sprinkler systems were estimated using industry-accepted software. Hydraulic calculations were performed with variations in primary and secondary water supplies, the number of sprinklers flowing, and floor level elevations. The results from the calculations were used to evaluate the expected sprinkler system performance.Multiple fire scenarios were analyzed in order to more fully understand the potential impact of the suppression systems to provide the flow of water required to control typical office fires within high-rise buildings. The analysis included single fires on different floors in the towers and in WTC 7 with various combinations of sprinklers activated and with primary and secondary water supplies. Additionally, hydraulic calculations based on simultaneous fires on up to a total of nine floors were performed. Estimates of suppression system performance in WTC 1, 2, and 7 on September 11, 2001, were also made.The following list summarizes the findings of the suppression and water supply study:•Except for specific areas that were exempted from required sprinkler coverage, sprinklers were installed throughout WTC 1, 2, and 7 on September 11, 2001.Draft for Public Comment Executive Summary •According to the documentation examined, the fire suppression systems in WTC 1, 2, and 7 were installed, for the most part, in a manner consistent with state-of-the-art practices inexistence at the time of their installation. The installations as documented, with severalminor exceptions, would satisfy current best practices.•Storage tanks, along with direct connections to the NYC water distribution system, supplied water for WTC 1 and WTC 2, and for floors 21 through 47 of WTC 7. Fire suppressionsystems for floors 1 through 20 in WTC 7 were supplied directly through the NYC waterdistribution system and an automatic fire pump, with no secondary supply.•The installation of the supply piping from the storage tanks on the 110th floor in WTC 1 and WTC 2 resulted in restricted flow capacity to several floors. The flow capacity was sufficientto supply the suppression systems, but the installation was not consistent with currentengineering best practices.•The suppression systems in WTC 1, 2, and 7 required manual initiation of the electrical fire pumps in order to provide supplemental water. An automatic supplemental water supply hasbeen required by National Fire Protection Association (NFPA) 14 for some time andrepresents best practice. Due to extensive damage to the sprinkler and standpipe systems inWTC 1 and WTC 2 on September 11, 2001, it is doubtful that automatic pumps would havemade any difference in performance.•The supply risers for automatic sprinkler systems in WTC 1, 2, and 7 were configured to provide redundant capabilities. However, the sprinkler floor level controls were installedwith one connection to the sprinkler water riser. This represented a single point of failurelocation for the water supply to the sprinklers on that floor.•The water flow capacities of the sprinkler systems installed in WTC 1, 2, and 7 were designed to provide densities considerably greater than typically provided for high-rise officebuildings. Based on hydraulic calculations, it was estimated that the sprinkler systems couldhave controlled a typical fire at a coverage area up to two to three times the specific designarea of 1,500 ft2. However, a coverage area of 4,500 ft2 constitutes less than 15 percent ofthe area of a single floor.•The standpipe and preconnected hose systems were consistent with the applicable requirements in the Building Code of New York City (BCNYC). They were not consistentwith the flow rates and durations specified by NFPA 13.•The loading berth and fuel oil pump rooms in WTC 7 were protected by dry-pipe sprinkler systems. The first floor room containing the 6,000 gal fuel oil tank was protected by anInergen clean agent fire suppression system.•The fifth floor generator room was not equipped with a sprinkler system, consistent with the BCNYC. No information was found that indicated that the generator/fuel day-tankenclosures elsewhere in WTC 7 were protected by a fire suppression system.Executive Summary Draft for Public Comment •Primary and backup power were provided in all three buildings, but the absence of remote redundancy of the power lines to emergency fire pumps could have affected the operability ofthe sprinkler and standpipe systems once power was lost.•Due to the magnitude of the initial fires and the likely aircraft impact-induced damage sustained to the suppression systems infrastructures in WTC 1 and WTC 2, it is notunexpected that the suppression systems present in these buildings failed to control the fireson September 11, 2001.E.3 FIRE ALARM SYSTEMSThe evaluation of the fire alarm systems, a review of applicable codes and standards, documentation of the normal operation of fully functional fire alarm systems, and their potential performance in WTC 1, 2, and 7 on September 11, 2001, were performed by subject experts at Rolf Jensen and Associates, Inc., under contract to NIST.Major features of the fire alarm systems in WTC 1, 2, and 7 are described based on a review of the available documentation. Details on the fire command station, fire alarm system functions, fire alarm system installation criteria, control panel configurations, fire alarm devices, and firefighter telephone system are provided. Additionally, the staff emergency response plan that provided direction for emergency response is outlined. The responsibilities of the fire safety director, deputy fire directors, assistant fire safety coordinator, and floor wardens are described.For WTC 1 and WTC 2, performance on September 1, 2001, was documented based on brief images of illuminated status lamps on the system’s control panels, which were filmed during the event, and through interviews with people who were in the buildings at the time. The performance of the WTC 7 fire alarm system was assessed on the basis of the printout of the fire alarm system’s remote monitoring system.The following is a summary of findings based upon the review of the building designs and analysis of the various fire alarm systems:•Because the WTC 1 and WTC 2 fire alarm system required manual activation to notify building occupants, the alarm signal was delayed until 12 min after impact in WTC 1.•The telephone circuits and the notification appliance circuits were not required to have the same performance requirements as the signaling line circuits.•Attempts were made to use the firefighter telephone systems in WTC 1 and WTC 2 on September 11, 2001; however the system was not functioning.•Although the fire alarm systems in WTC 1 and WTC 2 used multiple communication path risers, the systems experienced performance degradation, especially in WTC 1 where all firealarm notification and communication functions appear to have been lost above the floors ofimpact.Draft for Public Comment Executive Summary •The fire alarm system installed in WTC 7 sent to the monitoring company only one signal indicating a fire condition in the building on September 11, 2001. This signal did not containany specific information about the location of the fire within the building.E.4 SMOKEMANAGEMENTSubject experts at Hughes Associates, Inc., under contract to NIST, evaluated the design and installation of the smoke management systems in WTC 1, 2, and 7, reviewed applicable codes and standards, and documented the normal operation of the fully functional smoke management systems and their potential effect on smoke conditions in WTC 1 and WTC 2 on September 11, 2001.The review of building codes and standards determined those that were applicable to WTC 1, 2, and 7. Specifically, the versions of BCNYC that applied and the local laws that were enacted which pertain to smoke management are presented. This review was used as a basis for documenting building designs and evaluating system performance. Descriptions are provided of the basic architecture of each building as it pertains to the establishment of smoke control zones, heating, ventilation and air-conditioning (HVAC) components and layout relevant to smoke management, and sequences of operation of smoke management systems (i.e., activation of fans and positioning of dampers to control airflow during smoke control operations).Smoke management system performance of WTC 1 and WTC 2 was evaluated based on the understanding of the systems developed during the design reviews. Analysis was performed using industry-accepted software to analyze the interaction between the building and the HVAC systems to determine the extent to which building pressures could be maintained in order to control or prevent the spread of smoke from a zone of fire origin to the rest of the building. The ability of the documented smoke management system to perform under typical design fire scenarios was analyzed along with the ability of the – assumed to be fully functional – system to perform given the damage sustained and the extreme fire/smoke conditions that developed as a result of aircraft impacts on the building.In order to more fully understand the potential impact of smoke management systems within high-rise buildings, multiple smoke management strategies, design fire scenarios, building configurations and weather conditions were analyzed. In total, a set of 180 simulations were performed, and results were evaluated.The following are findings from the evaluation of the smoke management systems:•The smoke management systems in WTC 1 and WTC 2 were not initiated onSeptember 11, 2001.•Had the smoke purge sequence been initiated in WTC 1 or WTC 2, it is unlikely the system would have functioned as designed, due to damage caused by aircraft impacts.•WTC 1 and WTC 2 were not required by the 1968 BCNYC, as amended by Local Law 5 and Local Law 86, to have active smoke and heat venting and/or stair pressurization because theycontained automatic sprinklers throughout.Executive Summary Draft for Public Comment •Even if fully operational, none of the potential smoke management systems evaluated would have prevented smoke spread given the damage caused by aircraft impact.•During the events occurring on September 11, 2001, stair pressurization would have been ineffective in improving conditions for occupants trying to exit the building.•Installation of combination fire/smoke dampers in HVAC ductwork, which was not required in WTC 1 or WTC 2, may have acted to slow the development of hazardous conditions on theuppermost floors of the building, but would likely not have had a significant effect on theability of occupants to egress the building due to the impassibility of the exit stairways.。
外文翻译原文
IntroductionLatvian legislation for forest protection belts Latvian legislation demands that forest protection belts are established around all cities and towns. The concept of protection belts originates from the Soviet Era and is maintained in Latvian legislation despite the radical changes to the political system after regaining indepen-dence in 1991. The legal background for the establish-ment of protection belts is as follows:•Law on Protection Belts (1997, 2002)•Forest Law (2000)•Law on Planning of Territorial Development (1998).Designating a greenbelt around the city of Riga, LatviaJanis DonisLatvian State Forestry Research Institute ‘Silava’, Salaspils, LatviaAbstract: Latvian legislation demands that forest protection belts are established around all cities and towns. The main goal of a protection belt is to provide suitable opportuni-ties for recreation to urban dwellers and to minimise any negative impacts caused by urban areas on the surrounding environment. Legislation states the main principles to be adopted, which include the maximum area of protection belts, their integration in terri-torial development plans and restrictions placed on forest management activities. The largest part of the forest area around Riga is owned by the municipality of Riga, which, as a result, has two competing interests: to satisfy the recreational needs of the inhabitants of Riga, and to maximise the income from its property. In order to compile sufficient background information to solve this problem, the Board of Forests of Riga Municipality initiated the preparation of a proposal for the designation of a new protection belt.The proposal was based on the development and application of a theoretical framework developed during the 1980s. The analysis of the recreational value of the forest (5 class-es of attractiveness) was carried out based on categories of forest type, dominant tree species, dominant age, stand density, distance from urban areas and the presence of at-tractive objects. Information was derived from forest inventory databases, digital forest maps and topographic maps. Additional information was digitised and processed using ArcView GIS 3.2. Local foresters were asked about the recreation factors unique to differ-ent locations, such as the number of visitors and the main recreation activities. From a recreational point of view and taking into account legal restrictions and development plans for the Riga region, it was proposed to create three types of zones in the forest: a protection belt, visually sensitive areas and non-restricted areas.Key words:greenbelt forest, recreational value, GIS, zoningThe Law on Protection Belts states that protection belts around cities (with forests as part of a green zone)have to be established (a) to provide suitable conditions for recreation and the improvement of the health of urban dwellers, and (b) to minimise the negative im-pact of urban areas on the surrounding environment.Urban For.Urban Green.2 (2003):031–0391618-8667/03/02/01-031 $ 15.00/0Address for correspondence:Latvian State Forestry Re-search Institute ‘Silava’, Rı¯gas iela 111, Salaspils, LV-2169,Latvia. E-mail: donis@silava.lv© Urban & Fischer Verlaghttp://www.urbanfischer.de/journals/ufugRegulation nr 263 (19.06.2001) on the ‘Methodology for the establishment of forest protection belts around towns’issued by the Cabinet of Ministers (CM) states: (a) The area of a protection belt depends on the numberof inhabitants in the town: towns with up to 10,000 inhabitants should have a maximum of 100 ha of protection belt, those with between 10,000 and 100,000 inhabitants a maximum of 1,500 ha, and towns with more than 100,000 inhabitants a maxi-mum of 15,000 ha;(b) the borders of protection belts have to be able to beidentifiable on the ground, using features such as roads, ditches, power lines, and so forth;(c) protection belts have to be recorded in the territorialplans of regions adjacent to the town or city; and (d) establishment of protection belts has to be agreedupon by local municipalities.According to law, protection belts should be man-aged using adapted silvicultural measures. Clear-cut-ting, for example, is prohibited in a protection belt to mitigate any negative impacts of the city on the sur-rounding environment. The Forest Law of 2000 and subsequent regulations including the Regulation on Cutting of Trees, and the Regulation on Nature Conser-vation in Forestry define clear-cuts as felled areas larg-er than 0.1 ha where the basal area is reduced below a critical level in one year. These regulations also state the permitted intensity and periodicity of selective cut-ting (30–50%, at least 5 years between entries).The third element of the legal framework relevant for protection belts in Latvia is the Law on Planning of Territorial Development (1998). It defines:(a) Principles and responsibilities of the different or-ganisations involved;(b) the contents of territorial plans;(c) the procedures for public hearing; and(d) the procedures for the acceptance of plans.The law also states that protection belts around towns have to be designated in territorial plans. Thus, the legislation gives very detailed descriptions of the restrictions to maximum area, activities and guidelines for delineation and so forth, while there are no ‘rules’for the choice of what areas are to be included in pro-tection belts. It is up to territorial planners to propose what areas to include and for negotiation among mu-nicipalities to approve the selection.Protection belt for the city of RigaRiga and the Riga region are situated in the Coastal Lowland of Latvia within the Gulf of Riga. The main landform types are the Baltic Ice Lake plain, the Litto-rina Sea plain and the Limnoglacial plain and bog plain. The total area of the administrative area of the City of Riga covers 307.2 km2, and that of the Riga re-gion 3,059 km2. In 2000 the city of Riga had 815,000 inhabitants, while an additional 145,000 people resided in the greater Riga region. During the last decade the number of inhabitants in Riga decreased by 10.5%and in Riga region by 5.3%. In the mid-1990s the main types of industry in Riga were food processing, timber and wood processing, metal fabricating and engineer-ing, while in the region agriculture and forestry, wood processing, pharmaceuticals, and the power industry were the main activities. Due to reduced industrial ac-tivities today, the main sources of pollution in Riga re-gion are road transport and households.The greater part of the Riga region is covered by for-est, i.e. 1,642 km2or 53%. About 26% of the land is used for agriculture, 4% is covered by bogs, and 4% by water. The Riga region also has a coastal dune zone of some 30 km along the Gulf of Riga. The main tree species to be found in the Riga region are Scots pine (Pinus sylvestris L.),birch (Betula spp.) and Norway spruce (Picea abies (L.) Karsten) (see Table 1). In the administrative area of the city of Riga, 57 km2 or about 19% of the land area is forest. Scots pine is the domi-nant species, covering approx. 46.9 km2(i.e. 88% of the total forest area).According to the legislation described before, a pro-tection belt around Riga city, with a maximum size of 15,000 ha, could be designated. Moreover, any propos-al has to be agreed upon among 24 local municipalities. The Riga region is divided into 24 administrative units: 7 towns and 17 pagasts or ‘parishes’.Riga municipality currently owns more than 55,600 ha of forests. Most are situated in the vicinity of Riga. Four forest administrative districts lie completely with-in Riga region and close to Riga city (see Fig. 1). The total area of these districts is 44,158 ha out of which forest stands cover 36,064 ha (82%). Thus the Riga municipality forests of those 4 districts cover only 17% of the total forest area of the Region. The dominant tree species in the municipally owned forests are Scots32J.Donis:Designating a greenbelt around the city of Riga,LatviaUrban For.Urban Green.2 (2003)Table 1.Tree species composition in the Riga region Dominant tree Area covered, ha Average age, years species––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––Total Municipa-Total Municipa-lity*lity* Scots pine95,27627,3718581 Norway spruce20,8493,0175139Birch30,5585,1246056 Other10,438552––Total157,12136,0647369*Data only for the 4 forest districts of the Riga city munici-pality that are entirely situated within the Riga region.pine, birch and Norway spruce. These cover 76%, re-spectively 14% and 8% of the forest area. Other species cover less than 2% of the area.Until the re-establishment of Latvian independence almost all forestland was owned by the state but since then many areas have been returned to their former owners and are now privately owned. Current regula-tions state that until the designation of new boundaries for protection belts has been agreed upon, all forests of the previously existing and protected green zone have to remain protected whatever their functional role or ownership status. Consequently almost all forests of the Riga municipality located in the Riga region have management restrictions placed on them, and the same can be said for forests of other owners within the previ-ously existing green zone. Currently, therefore, on the one hand significant recreation opportunities for urban dwellers are provided, while on the other hand forest owners’rights to obtain income from timber harvest in the suburban areas continue to be restricted. Suburban municipalities also lose income because of reduced land taxes from land with management restrictions.The board of Forests of the Municipality of Riga there-fore initiated the preparation of a proposal to designate a new protection belt.Study to support protection belt designation The main objective of the study presented here has been to obtain background information in preparation for further discussions with local municipalities. Stud-ies in Latvia as well as elsewhere have revealed that recreational values of forests depend mainly on forest characteristics, location and level of pollution (Emsis et al. 1979; Emsis 1989; Holgen et al. 2000; Lindhagen & Hörnsten 2000; Rieps ˇas 1994; Su ¯na 1973, 1979). A very important aspect is the distance to the forest from places where people live (e.g. Rieps ˇas 1994). The abil-ity of a forest stand to purify the air by filtering or ab-sorbing dust, micro-organisms, and noxious gases de-pends on tree and shrub species composition, age, tree size and stand density (Emsis 1989). Stands purify the air most effectively at the time of maximum current an-nual volume increment, usually between 30 to 60 years of age in Latvian conditions, depending on species.Recreational value, on the other hand, increases with age (and tree size) and reaches its maximum consider-ably later. Taking into account the peculiarities of the dispersal of pollution as described by Laivin ‚s ˇ et al.(1993) and Za ¯lı¯tis (1993), selective cutting is prefer-able in the vicinity of a pollution source, especially ifJ.Donis:Designating a greenbelt around the city of Riga,Latvia 33Urban For.Urban Green.2 (2003)Fig. 1.Location ofthe Riga municipali-ty forests in the Riga region.the forest consists of a narrow strip between the pollu-tion source and housing. If the distance between a pol-lution source and housing exceeds several kilometres, a patch clear-cut system with stands of different ages is sufficient to provide a reduction in the negative impact of urban areas. Taking into account the fact that closer to residential areas it is more important to consider the visual qualities of the forest (e.g. Tyrväinen et al. 2003), this purification ability can generally be ignored when planning protection belts.MethodsThis study to support the designating of the Riga pro-tection belt used the following data sources for analysis (see Fig. 2): forest inventory databases, digital forest maps of the Riga municipal forests which are situated outside the administrative borders of the city (55,600 ha of which 44,158 ha located in the Riga region) (see Fig. 1), and corresponding topographic maps.The study and its developed proposal are based on an application of a theoretical approach developed during the 1980s by the Latvian State Forestry Research Insti-tute ‘Silava’(Emsis 1989) and the Lithuanian Forestry Research Institute (Riepsˇas 1994). According to the methodology developed by Emsis (1989), the first step in the process is to evaluate the recreational potential of the forest stands. This is carried out by analysing the following factors:• The tolerance of the forest ecosystem to different lev-els of anthropogenic (recreation) loading;• the status of forest ecosystems in terms of the damage or degradation as a result of recreational use;•the suitability of the landscape for non-utilitarian recreation (recreational value); and• the existing and potential levels of recreational loads.The second step involves evaluating the existing andexpected functional roles of the forest.The tolerance of the forest ecosystem to different levels of anthropogenic impact or loading is evaluated using a framework based on a combination of forest type, dominant tree species, dominant age group, soil type and relief, according to the stability of ecosystem. All stands are classified into one of five tolerance classes. The highest score is given to mature deciduous forests on mesotrophic and mesic soils on flat topogra-phy, while the lowest score is given to young pine stands on oligotrophic soils on steep slopes (forests on dunes).In this study ecosystem tolerance could not be evalu-ated, as it was primarily a desk using existing databas-es, and topographic relief maps were not available in digital form. The status of the forest ecosystem in rela-tion to damage or degradation was evaluated in terms of the degree of change in vegetation cover, under-growth, tree root exposure of the and level of littering, classified into three classes.Assessment of the recreational value of the forest stands was calculated using a formula developed by Riepsˇas (1994):Recreational value VR= (VS*kW*kS+VA)*kPWhere VSis stand suitability based on key internal at-tributes of the stand, such as species, age, stand densityand forest type. VSvalues range from 0 for young, high-density grey alder (Alnus incana L.) on wet peat soils, to 100 for average density mature pine stands ondry mineral soils. kwis a coefficient depending on the distance of the stand from watercourses, ranging from0.1 for stands further than 2 km from watercourses to1.0 for stands up to 500 m from watercourses. kSis a coefficient depending on the distance of the stand from urban areas, ranging from 0.1 for stands further than34J.Donis:Designating a greenbelt around the city of Riga,LatviaUrban For.Urban Green.2 (2003)Fig. 2.Structure of data sources used in data ana-lysis.80 km from Riga to 1.0 for stands within 30 km ofRiga. VA is an additional value depending on the pres-ence of attractive features, for example, 25 for forest stands up to 500 m from settlements, including summer cottages, or for areas intensively used for recreation ac-cording to information of local foresters. kP is a coeffi-cient depending on the level of environmental pollu-tion. Its value is 0 if the actual pollution level exceeds limit values, 0.5 if the level of environment pollution is between 50% and 100% of limit values, and 1 if the level of actual pollution is less than 50% of the limit values. In this study a coefficient of 1.0 was used, be-cause SO2and O3concentrations measured by Rigabackground measuring stations did not exceed 50% of the limit values (Fammler et al. 2000).The division of stands into classes of stand suitabili-ty is based on studies of visitors’preferences. Coeffi-cients kw, ksand VAare based on visitors’spatial distri-bution and show the ratio of the number of visitors in different zones. The evaluation of existing and expect-ed recreational loads was carried out by local foresters. They marked existing and potential recreation places on forest maps, including:•Small areas or sites for activities such as swimming, barbecuing, and so forth.•Recreation territories, defined as areas of 20 ha or more where people stay longer periods for walking, jogging, skiing or other forms of both active and pas-sive recreation.•Traditionally popular places for the collection of berries and mushrooms.•Recreational routes, including routes from public transport stops to recreation sites or recreation terri-tories, and between recreation sites and territories. For each recreation site and recreation territory data on the main seasons of use, the periods of use (week-days, weekends), and the average number of people in ‘rush-hours’during good weather conditions was col-lected or estimated.Data processing was carried out using ArcView GIS3.2a, Visual Fox pro and Microsoft Excel. VS values foreach stand were calculated from information in the for-est database using Visual Fox pro. Information collect-ed at a later stage from local foresters was digitised using separate themes (layers) in ArcView GIS 3.2a. Buffer zones along watercourses and water bodies, as well as residential areas, recreation sites and territoriesand recreation routes were created to get kW ,kSand VAvalues for each stand. Then VR values were calculatedfor each stand.A selection of recreation sites and territories was vis-ited by members of the project team in order to evalu-ate the state of the ecosystem with respect to wear and tear arising from different levels of recreational use. An evaluation of the existing functional role of each forest stand was carried out using the existing categories offorest protection. The anticipated future functional role was evaluated by annalysing the recreational value of stands, known expectations in terms of territorial de-velopment, and existing legal restrictions in order to find a compromise between recreation possibilities and other services of the forest. Next, a first draft of the protection belt was drawn according to experts’judge-ment. This draft included forests with high recreational value adjacent to residential areas and summer cot-tages, and larger tracts intensively used for recreation with medium to high recreational value.ResultsAccording to the original forest classification 65% of the total forest land area was designated as a commer-cial greenbelt forest, for which the main management goals are timber production and environmental consid-erations. The remaining 35% were designated as pro-tected (see Table 2). With regards to protected areas in Latvia: the main management goals of nature parks are nature conservation and recreation, including some ed-ucation. The goal for nature reserves is nature conser-vation, while that of the protected greenbelt forests is recreation.While interviewing local foresters it was revealed that they find it difficult to evaluate dispersed recreation loads (for example collection of berries, mushrooms). The assessments of foresters varied greatly and were considered to be unreliable. It was therefore decided to map only the places important for recreation, but not to use the inaccurate estimates of visitor numbers.In Latvia, special investigations have to be carried out in order to develop management objectives and principles for protected forests as part of the preparation of management plans. Pilot studies and visits to some of the recreation areas have revealed that the evaluation of the state of the forest ecosystem is useful only when de-veloping the detailed management plan. Even then, this is only the case for places identified by local foresters as recreation sites or territories, because otherwise it is too time consuming to carry out fieldwork which provides little useful additional information.Calculated VSvalues show that on average the forests studied have a medium suitability value for recreation (average score 47) (see Table 2). There are considerable differences between districts, with aver-age value ranging from 32 points in Olaine to 66 points in the Garkalne district. This indicates that the average stands in the Garkalne district are more suitable for recreation than those in other districts. If other aspects are taken into account, such as distance from wherepeople live, and VRvalues are calculated it can be seenJ.Donis:Designating a greenbelt around the city of Riga,Latvia35Urban For.Urban Green.2 (2003)that the districts are still ranked as follows: Garkalne,Jugla, Tireli and Olaine.Only 10% of the forest owned by Riga municipality within the Riga region were evaluated as having a high or very high recreational value. 12% had medium recreational value, while large areas used for the col-lection of berries and mushrooms were evaluated as having low or very low recreational value (60% of the total forest area) (see Table 3).More than 16% of the area is covered by bogs, for which according to the used methodology, recreational value was not evaluated at all. Some areas were recorded by the local foresters as important places for the collec-tion of berries. However, more valuable from a recre-ational point of view were those forests situated east and north-east of the city (Garkalne and Jugla districts),while the forests to the south (Olaine and Tireli districts)were found to have a lower recreational value (V R ).36J.Donis:Designating a greenbelt around the city of Riga,LatviaUrban For.Urban Green.2 (2003)Table 2.Distribution of forest by forest categories according to the original functional role Forest districtDataFormer forest category Total–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––Commercial Nature Nature Protected greenbelt forests parks reserves greenbelt forestsGarkalneArea, ha521.27,698.78,219.9Average of V S *61.966.566.2Average of V R **59.350.751.4JuglaArea, ha 8,376.74,098.812,475.4Average of V S 45.656.949.1Average of V R 22.034.025.7OlaineArea, ha 11,765.4707.512,473.0Average of V S 31.941.032.6Average of V R 8.527.410.0TireliArea, ha 8,689.5257.91,025.01,016.910,989.3Average of V S 40.666.710.059.342.3Average of V R 17.055.3 1.044.920.6TotalArea, ha 28,831.6779.11,025.013,522.044,157.6Average of V S 39.863.510.061.647.1Average of V R16.357.91.043.725.9* V S Suitability value – based on stand parameters (0–100 points).** V R Recreation value (0–125 points) based on stand parameters, distance to the residential areas, water and other attractive objects.Table 3.Distribution of forest areas by classes of attractiveness and by designated functional role Designated zoneDataClass of attractiveness Total –––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––n.a.Very low Low Medium High Very high 0<2525,1–5051–7575–100100<Protection belt Area, ha76.7560.12,266.42,222.7850.5743.66719.9Average of V R *0.012.036.063.390.0125.053.4Visually sensitive Area, ha 447.64,150.54,157.7853.4847.1179.810636.1Average of V R 0.07.837.460.996.7125.028.5Non-restricted Area, ha 6,664.715,389.12,548.61,090.5874.8234.026801.7Average of V R 0.0 5.234.761.197.2125.015.8TotalArea, ha 7,189.020,099.88,972.74,166.52,572.31,157.344157.6Average of V R0.06.236.362.294.6125.025.9*V R Recreation value (0–125 points) based on stand parameters, distance to the residential areas, water and other attractive objects.Areas along main roads and railways are known to be visually sensitive, because of the large number of peo-ple who can see them during travel. The same is true for forest in the vicinity of small villages. Taking into ac-count the fact that legislation prohibits clear-cuts in pro-tection belts – which is not always necessary in order to maintain the visual quality of the landscape – it was proposed, as part of the zoning strategy, to create so called visually sensitive areas. In these areas the forest owner (Riga municipality) is recommended to use more detailed landscape-planning techniques and to pay more attention to visual aspects during management.As a result of the study, seen from a recreational point of view and taking into account legal restrictions and so forth, it has been proposed to create three zoning categories: (1) protection belts, (2) visually-sensitive areas, and (3) non-restricted areas (see Fig. 3). The protection belt should include:• Forest with high recreational value adjacent to residen-tial areas and summer cottages, to form a 200–500 m wide belt.• Larger tracts of forestland intensively used for recre-ation.The zone of visually-sensitive areas should include:• Forests within the administrative borders of Riga mu-nicipality and in the vicinity of villages (up to 200–500 m distance).• Forests along roads of national and regional impor-tance, railways, watercourses and streams as a protec-tion belt of 100–300 m wide.• Places used for mushroom and berry collection in the original restricted protection belt.• Places that could become important for recreation in the near future.J.Donis:Designating a greenbelt around the city of Riga,Latvia 37Urban For.Urban Green.2 (2003)Table 4.Proposed distribution of forest categories in designated zones (in hectares)Designated zoneFormer forest category Grand Total––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––Commercial Nature Nature Protected greenbelt forests parks reserves greenbelt forests Protection belt355.2779.15,585.76,719.9Visually sensitive areas 3,503.97,132.110,636.1Non-restricted areas 24,972.51,025.0*804.226,801.7Total 28,831.6779.11,025.013,522.044,157.6*Forests within nature reserves are not intended for recreation; their primary management goal is nature conservation.Fig. 3.Proposal for zon-ing of the Riga municipalforests in Riga region.The remaining areas should consequently be classi-fied as non-restricted areas.A revision of the first draft plan was made taking into account the known prospective development plans of Riga and Riga region. As a result, for forests owned by Riga municipality and located in Riga region the pro-posal is to include 6,720 ha in the protection belt (see Table 3). Moreover, it has been suggested to designate 10,636 ha as visually-sensitive areas, but to omit the re-maining 26,802 ha from zoning, as these do not need special management from a recreation point of view. Average recreational values of stands in this area range from 53 (medium), through 28 (low) to 15 points (very low) respectively.As a result, the major part of the forest remains in the same functional category as in the original allocation (see Table 4). As was mentioned above, the classifica-tion described here is only based on recreational as-pects, thus forests in nature reserves are misleadingly shown as non-restricted forests. Only 5,586 ha out of the 13,500 thousand ha of the originally protected greenbelt forests are proposed to be included in the protection belt, while 355 ha of the previous commer-cial greenbelt forests are proposed to be placed under stronger protection.DiscussionForests owned by Riga municipality within the Riga re-gion are divided over 13 rural municipalities. Accord-ing to legislation, revised draft proposals for zoning Riga city forests have to be accepted by Riga munici-pality, while the final decision is up to Riga and the sur-rounding municipalities. The study presented here has provided a tentative estimate of the recreational value and suitability of the forests for recreation and can be used as a starting point for political discussions. At the very beginning the intention was to divide the forests in two categories: the protection belt and the remainder of the forest. During the study it was concluded, however, that a third category would be needed, that of visually sensitive areas. Within this category more attention would have to be paid to the amenity of the landscape, but there would be no need to drastically restrict com-mercial forest management. As nature parks are also designated for recreation, it has been proposed to in-clude all forests of nature parks in the protection belt. It has to be noted that all the forests within the adminis-trative borders of cities, and as such not included in this study, are designated as protected. As a consequence, the forest area available for recreation to the inhabi-tants of Riga would increase to 12,500 ha.Unlike many other European cities, where timber ex-traction is of small importance (Konijnendijk 1999),Riga municipal forests have a considerable economic role. It is estimated that the allowable annual cut in suburban forests amounts to 169,800 m3or 81% of the annual increment (Dubrovskis et al. 2002). It should be kept in mind that income from logging is used for for-est regeneration and tending, forest fire protection and maintenance of recreation facilities.The objective of this study was not to evaluate the precision of the method nor possible errors occurring when applying it. This study revealed, however, the in-completeness of the methodology used. Bogs, which are very sensitive to recreation loads, are ascribed quite a high level of attractiveness from a recreation point of view (for the collection of wild berries), but according to the methodology they are not evaluated at all. All watercourses were assumed to be attractive sites, while the preliminary evaluation of recreation loads showed this not to be true. The use of watercourses is very vari-able and obviously depends on water quality and vege-tation structure of the edges or banks. Another aspect which was not taken into account was that amenity of a forest is not simply the sum of the amenity values of forest stands (Pukkala et al. 1995).It seems that the evaluation based on dominant species is appropriate for screening areas, but for more detailed management plans, species mixture, the number of forest layers, and principles of landscape architecture also have to be taken into account (Bell 1999; Bell & Nikodemus 2000). Various studies have shown that people prefer uneven-aged forests (e.g. Melluma et al. 1982) and uneven-aged stands (e.g. Riepsˇas 1994). The impacts of the screening effect show that there are, even in the visually-sensitive and commercial zones, considerable areas with high and very high recreational value. This is mainly because delineation of zonal boundaries is carried out using easily distinguishable natural lines, and often it is not worth including single stands of high recreational value in the protection belt if, as a consequence, re-strictions on management would be placed over whole compartments of 50 ha.For the preparation of specific management guide-lines detailed field inventories have to be carried out. This has not been done in this study, where more re-liance was placed on the experience of local foresters and existing databases. Detailed economical calcula-tions have yet to be carried out in order to evaluate the direct and indirect value of the forest. These will also assist in obtaining more background information to be used as part of a holistic approach and for development of a decision support system to resolve contradictions between different interest groups.After acceptance of the draft plan by the municipali-ty of Riga, the process of negotiation between Riga and its surrounding municipalities is currently ongoing.38J.Donis:Designating a greenbelt around the city of Riga,Latvia Urban For.Urban Green.2 (2003)。
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PET的固相聚合反应：氮保护和高真空的影响摘要：我们研究过在固相聚合（SSP）薄（180mm）聚对苯二甲酸乙二醇酯（PET）切片反应条件的影响，在250℃下特性粘度（IV）增加和端基官能团耗尽，当固相聚合反应在真空条件下反应2小时，特性粘度从0.58增加到2.4l/g。
随着时间的推移，最初反应速率大大减慢，反应6小时特性粘度（IV）增加近2.75l/g，但我们仍能检测到羧基和末端羟基官能团的浓度分别为3和5，这表明结晶在限制末端官能团相互靠近，从而使官能团处于非活跃状态的作用，在这个阶段，升高温度至270℃使PET在真空下再次熔融，特性粘度在1.5小时内增至2.97l/g，可能由于结晶限制的释放，在熔体中允许一些不活跃端基相互接近。
我们发现这些暂时不活跃端基的计算对于一个特性粘度达1.3l/g的固相聚合的良好动力学描述是不可缺少的。
当使用氮气作为载气，比较在真空下的固相聚合，其反应速率和分子量会有所降低。
升华物是在固相聚合反应的真空条件下收集的，升华物由对苯二甲酸，单羟基对苯二甲酸酯，双羟乙基对苯二甲酸酯和环状低聚物组成。
这表明真空固相聚合的一个新的缩合机制的出现1介绍：固相聚合PET的后聚合常用来提高聚合物的数均分子量超过20000，期望应用于饮料瓶，轮胎和工业纤维。
当固相PET颗粒被加热到T=200~258℃时，通常认为有下列反应发生：酯交换/缩聚在这里，水和乙醇（EG）是可逆反应的副产物，无论通入惰性气体或保持减压，或者两种方法结合移除副产物都可促进正向反应的进行[6,7].整体反应速率受到内在反应速率结合的影响，活跃端基的扩散受[23-25]限制或促进酯交换反应[20],副产物从颗粒的内部扩散到颗粒表面[3,11,14,15,22,26]并且通过惰性气体移除。
高的客观反应速率下，尚未能根据酸（COOH）和末端羟基（OH），二乙二醇，醛等的浓度定义控制产品质量，研究已探讨反应参数（如温度[1,3,8-10,15,27-29]），颗粒大小[3,8,9,23,27,28]，结晶水平[13,16,25,27,28]，载气性质和速度[1,8,13,14,15,22]，催化剂浓度[30,31]等的影响。
在没有冷凝水扩散限制下导致其快速排除，逆反应排除，其反应动力学分别由EG（或水）的产率（或清除率）表示，有下列表达式表示[4,13,14,21],在式（6）中的2是因为考虑在链两端有两个反应点，速率常数要考虑这些相应活性基团。
1.1超高分子量PET的固相聚合虽然固有粘度=0.6-1.0l/g的PET有非常好的应用，如：纤维，薄膜和成型加工等，其固相聚合特性粘度高至3dl/g是为了溶液纺丝得到高模量高强度纤维[33-35].表一总结并说明了固相聚合PET的特性粘度大于1.5dl/g或是分子量大于70000。
以上，只有only Hsu [8], Ito et al. [40] and Boiko and Marikhin [24]曾报道过其动力学数据，但只限于IV（T）型材。
此外，表1的固相聚合总结只是仅在大气压力（含氮冲）或仅在真空下的条件下开展的。
固相聚合在其他条件相同但真空度或载气不相同的情况下是没有可比性的。
1.2固相聚合过程中末端基团的消耗一些作者按照随着固相聚合反应达到中等分子量时末端羟基和羧基的浓度的减少量，得到的结果列于表2。
这些研究都是只限于分子量不超过52000的聚合物，它是最近Zhi-Lianet al. [14], Wu et al. [23] and Kang [21]等人唯一分析的两个同步反应(式（1）和式（2）)末端基团的数据。
即使这些工作者没有考虑结晶在限制端基的相互辅助中的作用。
然而，他们没有面临符合动力学上的矛盾，因为他们限制了他们的分析分子量不超过52000。
Duh[16]对这种结晶作用做出了解释但忽略了酯化反应（式（2）），并没有直接测量端基的浓度，并限制了他分析的特性粘度（IV）小于1.3dl/g。
Jabarin[43] 和Wu et al. [23]报告称当[COOH]:[OH]=0.5时固相聚合能达到其最大反应速率。
Schaaf et al.[44]建议对于固相聚合的最大反应速其[COOH]:[OH]的最佳比值为0.3~0.6。
Chen and Chen [3]表明在优良的样品中高羟基（OH）浓度的会优先考虑，而在颗粒状PET中优先考虑高羧基（COOH）浓度。
然而，在特性粘度为0.25的PET的固相聚合中，Duh [4]最近发现在最初的PET聚合中固相聚合速率随着末端酸基的增加而逐渐减小。
末端羧基的消耗一般是由于酯化反应（式（2））。
虽然人们普遍认为环状低聚物在真空条件下或随惰性气体移除掉，另一种可能性是含有末端羧基的物质的升华，例如对苯二甲酸（PTA）和单羟乙基对苯二甲酸酯（MHET）在高温高真空的固相聚合。
对固相聚合反应中升华过程的分析将使得我们确定这样的升华是否起到重大的作用。
1.3载气性质和流量的影响几位作者报道[1,8,14,15,26],在高流速减缓之前，随着载气流量的增加后聚合反应的反应速率和反应程度增加，然而，只有Hsu [8] and Huang 和Walsh[15]提供关于气体速率（可能是最直接的传质参数）的信息。
Huang 和Walsh [15]总结出大小为1.1~2.7mm的微粒在190℃下，当氮气流量在0.8cm/s时反应速率足以达到固相聚合的最大反应速率。
氮气流量在2.5cm/s是220℃下反应达到最大反应速率的要求。
Hsu [8]发现大小在0.18~0.25mm的颗粒在氮气流量为2cm/s，温度为250℃下固相聚合7小时后，分子量由16500变为5800。
然而，在相同条件下使用氦或二氧化碳为载气能使分子量（Mn）分别达81000和90000。
Hsu将此归因于在聚合物中乙二醇载气扩散的影响和载气与乙二醇的相互作用。
Devotta and Mashelkar [13]量化了扩散的相关自由体积变化的影响效果。
Mallon et al. [45]发现在226℃下固相聚合0.1mmPET颗粒载气没有明显的作用效果。
虽然Aharoni [6]指出在氮减压下其效果优于只在氮蒸汽或高真空下，Fakirov [8]表明在固相聚合中反应介质（真空VS氮冲）没有显著影响。
如果有一个关于这种影响的详细分析，是不是可用？Chang [28]等人发现PET（20-30筛孔,特性粘度=0.72dl/g）在181℃淬火2小时的过程中，真空（相比氮冲）有更好的特性粘度保留和更少末端羧基产生。
在本文中，我们比较固相聚合超高压分子量在真空和氮冲条件下的动力学，不仅特性粘度，且酸和末端羟基的浓度都是用我们最近研发的基于核磁共振的技术监控。
结果分析了两歌分别产生乙二醇和水的同步反应的动力学（等式（1）和（2）），另外目的反应产生高摩尔质量的芳香凝聚体。
这种可能性是在固相聚合过程中通过收集和分析研究出的。
2、实验2.1原料聚酯切片从威尔顿研究中心（ICI,英国）获得，由特威隆研究所（阿纳姆）测定得到以下特征：分子量20500，二甘醇（DEG）为0.69wt%,Sb为212ppm,Ti为14ppm,P为78ppm. 氯仿（三氯甲烷，99.9%），氚代氯仿（CDCl3,99.9%D）,苯酚，四氯乙烷（三氯乙烯，97%）二甲亚砜（DMSO，d6,99%D原子），六氟异丙醇（异丙醇，99%），1，1，1-三氟甲苯（TFT，99%），4 - 吡咯烷基吡啶（98%），三氟乙酸（TFA，99%）和二羟乙基对苯二甲酸酯（BHET）从Aldrich公司获得。
苯酚（99%），氢氧化钠（98%），乙二醇（98%），二环己基碳二亚胺（DCC，99%），钽（99%）从默克得到。
所有化学品要照要求使用。
2.2核磁共振分析Varian Mercury Vx 400核磁共振波谱仪是用来进行1H和19F的核磁共振测量，用二甲亚砜，氚代氯仿CDCl3为溶剂，或氚代氯仿CDCl3与异丙醇或三氟乙酸的混合物作为溶剂。
2.3 PET的特性粘度PET在浓度为0.5g/dl的苯酚-三氯乙烯混合溶液（1:1，按质量）的相对粘度是用乌氏粘度计在30℃下测定的。
特性粘度是通过单点测量和使用以下的近似线性弹性链[47]估算的,几位工作者报道系数K及其在相同混合溶剂的测量，这些都总结在表3中。
2.4液相色谱-质谱(LC-MS法)分析LC-MS系统是安捷伦（1100系列，MS型61946D），使用柱Supersphere RP18e，150±3mm，颗粒直径4mm。
样品溶解在六氟异丙醇/四氢呋喃（1：10）的混合液中，以下色谱流出曲线(0.4毫升/分钟)被用到：在10分钟时MeOH/H2O/THF分别为50/50/0毫升，5分钟时MeOH/H2O/THF分别为100/0/0毫升，然后洗出四氢呋喃。
一个电喷雾界面用于电离分子，干燥气体的温度为350℃流率为10l/min。
毛细管的外加电压是4千伏。
喷雾器压力为50帕。
数据是在正电压模式下获得的.2.5在氮气中的固相聚合（SSP-N2）聚酯切片（平均质量0.045g）被压1分钟进入两个不锈钢铁板间的薄磁盘（直径1.5厘米，厚度180毫米）加热到160℃，在本文中这些薄的切片被用于所有的的固相聚合实验。
这些聚酯切片悬浮在一圆柱玻璃（内径27毫米）反应釜中浸入预先加热好的盐浴中，其温度被放置在反应堆的热电偶进行反馈控制。
气体流动速度为1l/min的氮气（室温和常压下）通过无水硫酸钙柱进行干燥（(W.H. Hammod Drierite, Xenia,俄亥俄州），通过穿过沉浸在同一盐浴的玻璃线圈进行预热，并介绍了是在反应器的底部。
氮气以5厘米每秒的速度通过薄切片到达表面。
通过保持氮气体积流量获得17m/s和59m/sd的较高速度，但限制氮气通过截面积较小的反应堆（内径15,8mm）流量。
切片首次在165℃反应堆干燥6小时。
反应堆被转移至另一相同的反应堆，但温度保持在258℃，在反应时间结束后撤出。
2.6氮气在固相聚合中的升华回收聚酯切片（1g）在250℃进行6小时以上，即将逸出的气体通过冷阱（玻璃线圈，浸在液氮中，长0.3m，内径7mm），然后气泡通过氯仿进入排气管排出。
在反应堆壁上、传输管线及冷阱中没有发现升华现象。
在缸里的氯仿可被蒸发的不留任何残留物。
2.7在真空的固相聚合（SSP-真空）薄的聚酯切片被放在一个玻璃制成的150ml圆底烧瓶连接到真空泵保持10毫托的压力。
烧瓶沉浸在温度控制盐缸直到烧瓶颈已被预热。
切片于165℃首次干燥6小时。
烧瓶被转移至另一相同的盐缸中，但温度保持252℃（烧瓶内250℃），反应时间结束后将烧瓶移出。