(完整版)温州大学本科毕业设计(论文)外文翻译

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本科毕业论文外文翻译【范本模板】

本科毕业论文外文翻译【范本模板】

本科毕业论文外文翻译外文译文题目:不确定条件下生产线平衡:鲁棒优化模型和最优解解法学院:机械自动化专业:工业工程学号: 201003166045学生姓名: 宋倩指导教师:潘莉日期: 二○一四年五月Assembly line balancing under uncertainty: Robust optimization modelsand exact solution methodÖncü Hazır , Alexandre DolguiComputers &Industrial Engineering,2013,65:261–267不确定条件下生产线平衡:鲁棒优化模型和最优解解法安库·汉泽,亚历山大·多桂计算机与工业工程,2013,65:261–267摘要这项研究涉及在不确定条件下的生产线平衡,并提出两个鲁棒优化模型。

假设了不确定性区间运行的时间。

该方法提出了生成线设计方法,使其免受混乱的破坏。

基于分解的算法开发出来并与增强策略结合起来解决大规模优化实例.该算法的效率已被测试,实验结果也已经发表。

本文的理论贡献在于文中提出的模型和基于分解的精确算法的开发.另外,基于我们的算法设计出的基于不确定性整合的生产线的产出率会更高,因此也更具有实际意义。

此外,这是一个在装配线平衡问题上的开创性工作,并应该作为一个决策支持系统的基础。

关键字:装配线平衡;不确定性; 鲁棒优化;组合优化;精确算法1.简介装配线就是包括一系列在车间中进行连续操作的生产系统。

零部件依次向下移动直到完工。

它们通常被使用在高效地生产大量地标准件的工业行业之中。

在这方面,建模和解决生产线平衡问题也鉴于工业对于效率的追求变得日益重要。

生产线平衡处理的是分配作业到工作站来优化一些预定义的目标函数。

那些定义操作顺序的优先关系都是要被考虑的,同时也要对能力或基于成本的目标函数进行优化。

就生产(绍尔,1999)产品型号的数量来说,装配线可分为三类:单一模型(SALBP),混合模型(MALBP)和多模式(MMALBP)。

毕业设计英文作文范文

毕业设计英文作文范文

毕业设计英文作文范文Title: The Importance of the Graduation Project in Academic Development。

The graduation project holds a pivotal role in the academic journey of students. It serves as a culmination of years of learning, a platform to showcase acquired skills, and an opportunity to delve deep into a specific subject matter. In this essay, I will elaborate on the significance of the graduation project and its impact on academic development.Firstly, the graduation project fosters independent learning and critical thinking skills. Unlike regular coursework where the parameters are often well-defined, the graduation project requires students to identify a research question or a problem statement independently. This process necessitates thorough literature review, data collection, and analysis, thereby honing research and analytical abilities. Moreover, formulating hypotheses, designingexperiments, or proposing solutions demand creativethinking and problem-solving skills, which are essentialfor academic and professional success.Secondly, the graduation project encourages interdisciplinary learning and collaboration. Many projects involve aspects from various fields, prompting students to integrate knowledge acquired from different courses. This interdisciplinary approach not only enriches the project but also broadens students' perspectives, enabling them to appreciate the interconnectedness of different subjects. Furthermore, collaboration with peers, mentors, or industry professionals enhances teamwork, communication, and project management skills, which are indispensable in any academic or professional setting.Additionally, the graduation project cultivates resilience and perseverance. Research, by its nature, is fraught with challenges, setbacks, and uncertainties. Students encounter obstacles ranging from experimental failures to data inconsistencies, requiring them to adapt, troubleshoot, and persist in the face of adversity.Overcoming these hurdles instills resilience and fortitude, attributes that are invaluable not only in academia but also in life.Moreover, the graduation project offers a platform for personal and intellectual growth. It provides students with the autonomy to explore topics of their interest, delveinto uncharted territories, and push the boundaries of knowledge. This journey of self-discovery not only enhances academic curiosity but also fosters a sense of ownership and accomplishment. Furthermore, presenting findings, defending arguments, and receiving feedback during project evaluations contribute to the development of presentation, communication, and critical evaluation skills, which are essential for academic and professional success.In conclusion, the graduation project is a cornerstone of academic development, offering students a unique opportunity to apply theoretical knowledge to real-world problems, fostering independent learning, interdisciplinary collaboration, resilience, and personal growth. By engaging in this endeavor, students not only demonstrate theiracademic prowess but also equip themselves with essential skills and attributes for future endeavors. Therefore, the graduation project stands as a testament to the culmination of academic journey and the beginning of a new chapter in students' intellectual and professional pursuits.。

本科毕业论文英文版

本科毕业论文英文版

本科毕业论文英文版毕业论文通常是一篇较长的有文献资料佐证的学术研究论文; 主要目的是探索、讨论或分析一个实际的或带有理论性的问题。

下文是店铺为大家整理的关于本科毕业论文英文版的范文,欢迎大家阅读参考! 本科毕业论文英文版篇1人与自然环境Abstract The first Industrial Revolution happened in 1760s.Since that time, human have began to explore and conquer nature. Due to excessive development, and hunting for natural resources, which lead to a series of environmental problems. Men have to let themselves to reflect and reposition the relationship between man and nature. Marxist view of nature studying this work has great theoretical significance and practical significance for the relationship between human and nature. Marxism stressed that people who live in the nature must respect the development of objective law of nature. Men can play their own subjective initiative to transform nature, but the transformation is based on respect nature for the objective law of the premise. The relationship between man and nature is objective existence. It can not be transcended. Nowadays the ecological environment is cruelly destroyed by people, which promote the harmonious development of man and nature has become more and more concerned. Jack London is a famous American realism writer. All his life, he totally created about 50 works, most famous works are The Call Of the Wild, The Sea Wolf, The White Fang. And the most famous one should be The Call of the Wild, which is based on his personal experience in the big social background and creation of dog novels. Marxist view of nature in the novel is the avoiding of the crisis of human spiritual,human’s responsibility to nature, returning to the harmony of man and nature.,and how to create a harmonious relationship between man and nature. The development of human civilization should never dehumanize all kinds of animals. People should not be beyond all the laws of nature, and should respect animals, respect nature. Jack London condemns people who recklessly consume and despoil the nature, man should build a harmonious, equal, healthy, enduring relationship between man and nature.Keywords: man and nature; Marxism; The Call of the Wild; Jack London摘要:从十八世纪六十年代第一次工业革命开始,人类为了自己的利益开始探寻自然,征服自然。

毕业设计(论文)外文原文及译文

毕业设计(论文)外文原文及译文

毕业设计(论文)外文原文及译文一、外文原文MCUA microcontroller (or MCU) is a computer-on-a-chip. It is a type of microcontroller emphasizing self-sufficiency and cost-effectiveness, in contrast to a general-purpose microprocessor (the kind used in a PC).With the development of technology and control systems in a wide range of applications, as well as equipment to small and intelligent development, as one of the single-chip high-tech for its small size, powerful, low cost, and other advantages of the use of flexible, show a strong vitality. It is generally better compared to the integrated circuit of anti-interference ability, the environmental temperature and humidity have better adaptability, can be stable under the conditions in the industrial. And single-chip widely used in a variety of instruments and meters, so that intelligent instrumentation and improves their measurement speed and measurement accuracy, to strengthen control functions. In short,with the advent of the information age, traditional single- chip inherent structural weaknesses, so that it show a lot of drawbacks. The speed, scale, performance indicators, such as users increasingly difficult to meet the needs of the development of single-chip chipset, upgrades are faced with new challenges.The Description of AT89S52The AT89S52 is a low-power, high-performance CMOS 8-bit microcontroller with 8K bytes of In-System Programmable Flash memory. The device is manufactured using Atmel's high-density nonvolatile memory technology and is compatible with the industry-standard 80C51 instruction set and pinout. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. By combining a versatile 8-bit CPU with In-System Programmable Flash on a monolithic chip, the Atmel AT89S52 is a powerful microcontroller which provides a highly-flexible and cost-effective solution to many embedded control applications.The AT89S52 provides the following standard features: 8K bytes ofFlash, 256 bytes of RAM, 32 I/O lines, Watchdog timer, two data pointers, three 16-bit timer/counters, a six-vector two-level interrupt architecture, a full duplex serial port, on-chip oscillator, and clock circuitry. In addition, the AT89S52 is designed with static logic for operation down to zero frequency and supports two software selectable power saving modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial port, and interrupt system to continue functioning. The Power-down mode saves the RAM contents but freezes the oscillator, disabling all other chip functions until the next interrupt or hardware reset.Features• Compatible with MCS-51® Products• 8K Bytes of In-System Programmable (ISP) Flash Memory– Endurance: 1000 Write/Erase Cycles• 4.0V to 5.5V Operating Range• Fully Static Operation: 0 Hz to 33 MHz• Three-level Program Memory Lock• 256 x 8-bit Internal RAM• 32 Programmable I/O Lines• Three 16-bit Timer/Counters• Eight Interrupt Sources• Full Duplex UART Serial Channel• Low-power Idle and Power-down Modes• Interrupt Recovery from Power-down Mode• Watchdog Timer• Dual Data Pointer• Power-off FlagPin DescriptionVCCSupply voltage.GNDGround.Port 0Port 0 is an 8-bit open drain bidirectional I/O port. As an output port, each pin can sink eight TTL inputs. When 1s are written to port 0 pins, the pins can be used as high-impedance inputs.Port 0 can also be configured to be the multiplexed low-order address/data bus during accesses to external program and data memory. In this mode, P0 has internal pullups.Port 0 also receives the code bytes during Flash programming and outputs the code bytes during program verification. External pullups are required during program verification.Port 1Port 1 is an 8-bit bidirectional I/O port with internal pullups. The Port 1 output buffers can sink/source four TTL inputs. When 1s are written to Port 1 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 1 pins that are externally being pulled low will source current (IIL) because of the internal pullups.In addition, P1.0 and P1.1 can be configured to be the timer/counter 2 external count input (P1.0/T2) and the timer/counter 2 trigger input (P1.1/T2EX), respectively.Port 1 also receives the low-order address bytes during Flash programming and verification.Port 2Port 2 is an 8-bit bidirectional I/O port with internal pullups. The Port 2 output buffers can sink/source four TTL inputs. When 1s are written to Port 2 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 2 pins that are externally being pulled low will source current (IIL) because of the internal pullups.Port 2 emits the high-order address byte during fetches from external program memory and during accesses to external data memory that use 16-bit addresses (MOVX @ DPTR). In this application, Port 2 uses strong internal pull-ups when emitting 1s. During accesses to external data memory that use 8-bit addresses (MOVX @ RI), Port 2 emits the contents of the P2 Special Function Register.Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.Port 3Port 3 is an 8-bit bidirectional I/O port with internal pullups. The Port 3 output buffers can sink/source four TTL inputs. When 1s are written to Port 3 pins, they are pulled high by the internal pullups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (IIL) because of the pullups.Port 3 also serves the functions of various special features of the AT89S52, as shown in the following table.Port 3 also receives some control signals for Flash programming and verification.RSTReset input. A high on this pin for two machine cycles while the oscillator is running resets the device. This pin drives High for 96 oscillator periods after the Watchdog times out. The DISRTO bit in SFR AUXR (address 8EH) can be used to disable this feature. In the default state of bit DISRTO, the RESET HIGH out feature is enabled.ALE/PROGAddress Latch Enable (ALE) is an output pulse for latching the low byte of the address during accesses to external memory. This pin is also the program pulse input (PROG) during Flash programming.In normal operation, ALE is emitted at a constant rate of 1/6 the oscillator frequency and may be used for external timing or clocking purposes. Note, however, that one ALE pulse is skipped during each access to external data memory.If desired, ALE operation can be disabled by setting bit 0 of SFR location 8EH. With the bit set, ALE is active only during a MOVX or MOVC instruction. Otherwise, the pin is weakly pulled high. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.PSENProgram Store Enable (PSEN) is the read strobe to external program memory. When the AT89S52 is executing code from external program memory, PSENis activated twice each machine cycle, except that two PSEN activations are skipped during each access to external data memory.EA/VPPExternal Access Enable. EA must be strapped to GND in order to enable the device to fetch code from external program memory locations starting at 0000H up to FFFFH. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset. EA should be strapped to VCC for internal program executions.This pin also receives the 12-volt programming enable voltage (VPP) during Flash programming.XTAL1Input to the inverting oscillator amplifier and input to the internal clock operating circuit.XTAL2Output from the inverting oscillator amplifier.Special Function RegistersNote that not all of the addresses are occupied, and unoccupied addresses may not be implemented on the chip. Read accesses to these addresses will in general return random data, and write accesses will have an indeterminate effect.User software should not write 1s to these unlisted locations, since they may be used in future products to invoke new features. In that case, the reset or inactive values of the new bits will always be 0.Timer 2 Registers:Control and status bits are contained in registers T2CON and T2MOD for Timer 2. The register pair (RCAP2H, RCAP2L) are the Capture/Reload registers for Timer 2 in 16-bit capture mode or 16-bit auto-reload mode.Interrupt Registers:The individual interrupt enable bits are in the IE register. Two priorities can be set for each of the six interrupt sources in the IP register.Dual Data Pointer Registers: To facilitate accessing both internal and external data memory, two banks of 16-bit Data Pointer Registers areprovided: DP0 at SFR address locations 82H-83H and DP1 at 84H-85H. Bit DPS = 0 in SFR AUXR1 selects DP0 and DPS = 1 selects DP1. The user should always initialize the DPS bit to the appropriate value before accessing the respective Data Pointer Register.Power Off Flag:The Power Off Flag (POF) is located at bit 4 (PCON.4) in the PCON SFR. POF is set to “1” during power up. It can be set and rest under software control and is not affected by reset.Memory OrganizationMCS-51 devices have a separate address space for Program and Data Memory. Up to 64K bytes each of external Program and Data Memory can be addressed.Program MemoryIf the EA pin is connected to GND, all program fetches are directed to external memory. On the AT89S52, if EA is connected to VCC, program fetches to addresses 0000H through 1FFFH are directed to internal memory and fetches to addresses 2000H through FFFFH are to external memory.Data MemoryThe AT89S52 implements 256 bytes of on-chip RAM. The upper 128 bytes occupy a parallel address space to the Special Function Registers. This means that the upper 128 bytes have the same addresses as the SFR space but are physically separate from SFR space.When an instruction accesses an internal location above address 7FH, the address mode used in the instruction specifies whether the CPU accesses the upper 128 bytes of RAM or the SFR space. Instructions which use direct addressing access of the SFR space. For example, the following direct addressing instruction accesses the SFR at location 0A0H (which is P2).MOV 0A0H, #dataInstructions that use indirect addressing access the upper 128 bytes of RAM. For example, the following indirect addressing instruction, where R0 contains 0A0H, accesses the data byte at address 0A0H, rather than P2 (whose address is 0A0H).MOV @R0, #dataNote that stack operations are examples of indirect addressing, so the upper 128 bytes of data RAM are available as stack space.Timer 0 and 1Timer 0 and Timer 1 in the AT89S52 operate the same way as Timer 0 and Timer 1 in the AT89C51 and AT89C52.Timer 2Timer 2 is a 16-bit Timer/Counter that can operate as either a timer or an event counter. The type of operation is selected by bit C/T2 in the SFR T2CON (shown in Table 2). Timer 2 has three operating modes: capture, auto-reload (up or down counting), and baud rate generator. The modes are selected by bits in T2CON.Timer 2 consists of two 8-bit registers, TH2 and TL2. In the Timer function, the TL2 register is incremented every machine cycle. Since a machine cycle consists of 12 oscillator periods, the count rate is 1/12 of the oscillator frequency.In the Counter function, the register is incremented in response to a1-to-0 transition at its corresponding external input pin, T2. In this function, the external input is sampled during S5P2 of every machine cycle. When the samples show a high in one cycle and a low in the next cycle, the count is incremented. The new count value appears in the register during S3P1 of the cycle following the one in which the transition was detected. Since two machine cycles (24 oscillator periods) are required to recognize a 1-to-0 transition, the maximum count rate is 1/24 of the oscillator frequency. To ensure that a given level is sampled at least once before it changes, the level should be held for at least one full machine cycle.InterruptsThe AT89S52 has a total of six interrupt vectors: two external interrupts (INT0 and INT1), three timer interrupts (Timers 0, 1, and 2), and the serial port interrupt. These interrupts are all shown in Figure 10.Each of these interrupt sources can be individually enabled or disabledby setting or clearing a bit in Special Function Register IE. IE also contains a global disable bit, EA, which disables all interrupts at once.Note that Table 5 shows that bit position IE.6 is unimplemented. In the AT89S52, bit position IE.5 is also unimplemented. User software should not write 1s to these bit positions, since they may be used in future AT89 products. Timer 2 interrupt is generated by the logical OR of bits TF2 and EXF2 in register T2CON. Neither of these flags is cleared by hardware when the service routine is vectored to. In fact, the service routine may have to determine whether it was TF2 or EXF2 that generated the interrupt, and that bit will have to be cleared in software.The Timer 0 and Timer 1 flags, TF0 and TF1, are set at S5P2 of the cycle in which the timers overflow. The values are then polled by the circuitry in the next cycle. However, the Timer 2 flag, TF2, is set at S2P2 and is polled in the same cycle in which the timer overflows.二、译文单片机单片机即微型计算机,是把中央处理器、存储器、定时/计数器、输入输出接口都集成在一块集成电路芯片上的微型计算机。

毕业设计英文翻译原文

毕业设计英文翻译原文

编号:毕业设计(论文)外文翻译(原文)院(系):计算机科学与工程学院专业:自动化学生姓名:肖健学号:0600320126指导教师单位:计算机科学与工程学院姓名:王改云职称:教授2010年6月1日The Application of Visualization Technology in ElectricPower Automation SystemWang Chuanqi, Zou QuanxiElectric Power Automation System Department of Yantai Dongfang Electronics Information IndustryCo., Ltd.Abstract: Isoline chart is widely used chart. The authors have improved the existing isoline formation method, proposed a simple and practical isoline formation method, studied how to fill the isoline chart, brought about a feasible method of filling the isoline chart and discussed the application of isoline chart in electric power automation system.Key words: Visualization; Isoline; Electric power automation systemIn the electric power system industry, the dispatching of electric network becomes increasingly important along with the expansion of electric power system and the increasing demands of people towards electric power. At present, electric network dispatching automation system is relatively advanced and relieves the boring and heavy work for operation staff. However, there is a large amount or even oceans of information. Especially when there is any fault, a large amount of alarm information and fault information will flood in the dispatching center. Faced with massive data, operation staff shall rely on some simple and effective tool to quickly locate the interested part in order to grasp the operation state of the system as soon as possible and to predict, identify and remove fault.Meanwhile, the operation of electric power system needs engineers and analysts in the system to analyze a lot of data. The main challenge that a system with thousands of buses poses for electric power automation system is that it needs to supply a lot of data to users in a proper way and make users master and estimate the state of the system instinctively and quickly. This is the case especially in electric network analyzing software. For example, the displaying way of data is more important in analyzing the relations between the actual trend, planned trend of electric network and the transmission capacity of the system. The application of new computer technology and visualization technology in the electric power automation system can greatly satisfy new development and new demands of electric power automation system.Th e word “Visualization” originates from English “Visual” and its original meaning is visual and vivid. In fact, the transformation of any abstract things and processes into graphs and images can be regarded as visualization. But as a subject term, the word “Visualization” officially appeared in a seminar held by National Science Foundation (shortened as NSF) of the USA in February 1987. The official report published after the seminar defined visualization, its covered fields and its recent and long-term research direction, which symbolized that “Visualization” became mature as a subject at the international level.The basic implication of visualization is to apply the principles and methods of computer graphics and general graphics to transforming large amounts of data produced by scientific and engineering computation into graphs and images and displaying them in a visual way. It refers to multi research fields such as computer graphics, image processing, computer vision, computer-aided design (CAD) and graphical user interface (GUI), etc. and has become an important direction for the current research of computer graphics.There are a lot of methods to realize visualization and each method has its unique features and applies to different occasions. Isoline and isosurface is an important method in visualization and can be applied to many occasions. The realization of isoline (isosurface) and its application in the electric power automation system will be explained below in detail.1、 Isoline (Isosurface)Isoline is defined with all such points (x i, y i), in which F(x i, y i)=F i (F i is a set value), and these points connected in certain order form the isoline of F(x,y) whose value is F i…Common isolines such as contour line and isotherm, etc.are based on the measurement of certain height and temperature.Regular isoline drawing usually adopts grid method and the steps are as follows:gridingdiscrete data;converting grid points into numerical value;calculating isoline points; tracing isoline; smoothing and marking isoline; displaying isoline or filling the isoline chart. Recently, some people have brought about the method of introducing triangle grid to solve the problems of quadrilateral grid. What the two methods have in common is to use grid and isoline points on the grid for traveling tracing, which results in the following defects in the drawing process:(1) The two methods use the grid structure, first find out isoline points on each side of certain quadrilateral grid or triangle grid, and then continue to find out isoline points from all the grids, during which a lot of judgment are involved, increasing the difficulty of program realization. When grid nodes become isoline points, they shall be treated as singular nodes, which not only reduces the graph accuracy but also increases the complexity of drawing.(2) The two methods produce drawn graphs with inadequate accuracy and intersection may appear during traveling tracing. The above methods deal with off-grid points using certain curve-fitting method. That is, the methods make two approximations and produce larger tolerance.(3) The methods are not universal and they can only deal with data of grid structure. If certain data is transformed into the grid structure, interpolation is needed in the process, which will definitely reduce the accuracy of graphs.To solve the problems, we adopt the method of raster graph in drawing isoline when realizing the system function, and it is referred to as non-grid method here. This method needs no grid structures and has the following advantages compared to regular methods:(1) Simple programming and easily realized, with no singular nodes involved and no traveling tracing of isoline. All these advantages greatly reduce the complexity of program design.(2)Higher accuracy. It needs one approximation while regular methods need two or more.(3) More universal and with no limits of grid1.1 Isoline Formation Method of Raster GraphThe drawing of raster graph has the following features: the area of drawing isoline is limited and is composed of non-continuous points. In fact, raster graph is limited by computer screen and what people can see is just a chart formed by thousands of or over ten thousand discrete picture elements. For example, a straight line has limited length on computers and is displayed with lots of discrete points. Due to the limitations of human eyes, it seemscontinuous. Based on the above features, this paper proposes isoline formation method of raster graph. The basic idea of this method is: as computer graphs are composed of discrete points, one just needs to find out all thepicture element points on the same isoline, which will definitely form this isoline.Take the isoline of rectangular mountain area for example to discussdetailed calculation method. Data required in calculation is the coordinates and altitude of each measuring point, i.e., (x i ,y i ,z i ), among which z i represents the altitude of No.i measuring point and there are M measuring points in total. Meanwhile, the height of isoline which is to be drawn is provided. For example, starting from h 0 , an isoline is drawn with every height difference of ∆h0 and total m isolines are drawn. Besides, the size of the screen area to be displayed is known and here (StartX,StartY) represents the top left corner of this area while (EndX ,EndY)represents the low right corner of this area. The calculation method for drawing its isoline is as follows:(1) Find out the value of x i and y i of the top left corner and low right corner points in the drawing area, which are represented by X max ,X min ,Y max ,Y min ;(2)Transform the coordinate (x i ,y i ) into screen coordinate (SX i ,SY i )and the required transformation formula is as follows:sx i =x i -X min /X max -X min (EndX-StartX)sy i =y i -Y min /Y max -Y min (EndY-StartY)Fig. 1 Height computation sketch(3) i =startX,j=StartY; Suppose i =startX,j=StartY;(4) Use the method of calculating height (such as distance weighting method and least square method, etc.) to calculate out the height h 1, h 2, h 3 of points (i,j), (i+1,j) and (i,j+1), i.e., the height of the three points P 1, P 2 and P 3 in Fig. 1;(5) Check the value of h 1, h 2, h 3 and determine whether there is any isoline crossing according to the following methods:①k=1,h=h 0;①k=1,h=h 0;②Judge whether (P 1-h)*(P 2-h)≤0 is justified. If justified, continue the next step; otherwise, perform ⑤;③Judge whether |P1-h|=|P2-h| is justified. If justified, it indicates that there is an isoline crossing P1, P2, dot the two points and jump to (6); otherwise, continue next step;④Judge whether |P1-h|<|P2-h|is justified. If justified, it indicates that there is an isoline crossing P1, dot this point; otherwise, dot P2;⑤Judge whether (P1-h)*(P3-h)≤0 is justified. If justified, con tinue next step; otherwise, perform ⑧.⑥Judge whether|P1-h|=|P3-h|is justified. If justified, dot the two points P1\,P3 and jump to (6);otherwise, jump to ⑤;⑦Judge whether|P1-h|<|P3-h|is justified. If justified, dot P1; otherwise, dot P3;⑧Suppose k:=k+1 and judge whether k<m+1 I is justified. If unjustified, continue next step; otherwise, suppose h:=h+∆h0 and return to ②.(6) Suppose j:j+1 and judge whether j<EndY is justified. If unjustified, continue next step; otherwise, return to (4);(7) Suppose i:=i+1 and judge whether i<EndX is justified. If unjustified, continue next step; otherwise, return to (4);(8) The end.In specific program design, in order to avoid repeated calculation, an array can be used to keep all the value of P2 in Column i+1 and another variable is used to keep the value of P3.From the above calculation method, it can be seen that this method doesn’t involve the traveling of isoline, the judgment of grid singular nodes and the connection of isoline, etc., which greatly simplifies the programming and is easily realized, producing no intersection lines in the drawn chart.1.2 Griding and Determining NodesTime consumption of a calculation method is of great concern. When calculating the height of (i,j), all the contributing points to the height of this point need to be found out. If one searches through the whole array, it is very time consuming. Therefore, the following regularized grid method is introduced to accelerate the speed.First, two concepts, i.e., influence domain and influence point set, are provided and defined as follows:Definition 1: influence domain O(P) of node P refers to the largest area in which this nodes has some influence on other nodes. In this paper, it can refer to the closed disc with radius as r (predetermined) or the square with side length as a (predetermined).Definition 2: influence point set S(P)of node P refers to the collection of all the nodes which can influence node P. In this paper, it refers to the point set with the number of elements as n (predetermined), i.e., the number of all the known contributing nodes to the height of node (i,j) can only be n and these nodesare generally n nodes closet to node P.According to the above definition, in order to calculate out the height of any node (i,j), one just needs to find out all the nodes influencing the height of this node and then uses the interpolation method according to two-dimensional surface fitting. Here, we will explain in detail how to calculate out the height of node (i,j) with Definition 1, i.e., the method of influence domain, and make similar calculation with Definition 2.Grid structure is used to determine other nodes in the influence domain of node (i,j). Irregular area is covered with regular grid, in which the grids have the same size and the side of grid is parallel with X axis and Y axis.The grid is described as follows:(x min,x max,NCX)(y min,y max,NCY)In the formula, x min, y max and x max, y max are respectively the minimum and maximum coordinates of x, y direction of the area; NCX is the number of grids in X direction; NCY is the number of grids in Y direction.Determining which grid a node belongs to is performed in the following two steps. Suppose the coordinate of this node is (x,y). First, respectively calculate its grid No. in x direction and y direction, and the formula is as follows:IX=NCX*(x-x min)/(xmax-x min)+1;IY=NCY(y-y min)/(y max-y min)+1。

本科毕业设计(论文)外文翻译

本科毕业设计(论文)外文翻译
1.引言
重金属污染存在于很多工业的废水中,如电镀,采矿,和制革。
2.实验
2.1化学药剂
本实验所使用的药剂均为分析纯,如无特别说明均购买自日本片山化工。铅离子储备液通过溶解Pb(NO3)2配制,使用时稀释到需要的浓度。HEPES缓冲液购买自Sigma–Aldrich。5 mol/L的HCl和NaOH用来调整pH。
附5
华南理工大学
本科毕业设计(论文)翻译
班级2011环境工程一班
姓名陈光耀
学号201130720022
指导教师韦朝海
填表日期
中文译名
(1)巯基改性纤维素对葡萄糖溶液中铅的吸附(2)黄原酸化橘子皮应用于吸附水中的铅离子
外文原文名
(1)Adsorption of Pb(II) from glucose solution on thiol-functionalized cellulosic biomass
2.5分析方法
铅离子的浓度用分光光度计在616 nm波长处用铅与偶氮氯膦-III络合物进行分析。葡萄糖含量采用苯酚—硫酸分光光度法测定。所有的实验均进行三次,已经考虑好误差。
3.结果和讨论
3.1FTIR分析和改性脱脂棉对铅(II)的吸附机制
图1是脱脂棉、改性脱脂棉在400-4000 cm-1(A)和2540-2560 cm-1(B)范围内的红外光谱图。可以看出,改性后改性脱脂棉的红外光谱图中在1735.71 cm-1处出现了一个新的吸收峰是酯基C=O的拉伸振动峰,可见改性脱脂棉中已经成功引入巯基官能团。同时,在2550.52 cm-1出现的一个新吸收峰代表的是S-H官能团的弱吸收峰,更深一层的证明了巯基已经嫁接到脱脂棉上。图1(b)是2540-2560 cm-1光谱范围的一个放大图像,可以清楚的观察到S-H官能团的弱吸收峰。进一步证明了酯化改性脱脂棉引入巯基是成功的。而从吸附后的曲线可以看到,2550.52cm-1处S-H的吸收峰消失,证明了硫原子和Pb(II)络合物的形成,同时1735.71cm-1处C=O的吸收峰强度看起来有轻微的减弱可能也是和Pb(II)的络合吸附有关。

大学毕业论文英文翻译及原文

大学毕业论文英文翻译及原文

大学毕业论文英文翻译中文译文计算机网络每个一个世纪都有一种主导地位的技术。

18世纪伴随着工业革命的到来的是大型机械系统的时代;19世纪是蒸汽机的时代,而20世纪的发展历程中,关键的技术是信息收集、处理和分发。

在其他的发展方面,我们还可以看到:遍布全球的电话网络的建立起来了,无线电广播和电视的出现了,计算机工业诞生了,并且以超乎想象的速度在成长;另外通信卫星也发射上天了。

技术的快速发展的一个直接结果是,这些领域正在快速地融合,信息收集、传输、存储和处理之间的差别正在迅速地消失。

对于具有数百个办公室的大型组织来说,尽管这些办公室分布在广阔的地理区域中,但未来期望的情景是,工作人员只要单击一下按钮,就可以查看最远处分部的状态。

随着信息收集、处理和分发能力的不断提高,我们对于更加复杂的信息处理技术的需求也增长得更快。

与其他的工业(比如汽车和航空运输业)相比,计算机工业还是非常年轻,尽管如此,计算机技术却在很短的时间内有了惊人的进展。

在计算机诞生之初的20年间,计算机系统是高度集中化的,通常位于一个很大的房间中。

该房间通常配有玻璃墙,参观的人透过玻璃墙可以欣赏到里边伟大的电子奇迹。

中等规模的公司或者大学可能会有一台或者两台计算机,而大型的研究机构最多也就几十台计算机。

要在20年内生产出大量同样功能但是体积比邮票还小的计算机,在当时的人们看来纯属科学幻想。

计算机和通信的结合对于计算机系统的组织方式产生了深远的影响。

把一台大型的计算机放在一个单独的房间中,然后用户带着他们的处理任务去房间里上机,这种"计算机中心"的概念现在已经完全过时了。

由一台计算机来处理整个组织中所有的计算需求,这种老式的模型已经被新的模型所取代,在新的模型下,由大量独立的,但相互连接起来的计算机来共同完成计算任务。

这些系统称为计算机网络(computer networks)。

如何设计这些网络,并且将这些网络组织起来,这就是本书的主题。

大学本科毕业设计--英文原文+中文翻译

大学本科毕业设计--英文原文+中文翻译

Library of C the CNC industrialdeveloped tens of thousands and educational field, he hasNUMERICAL CONTROLNumerical Control technology as it is known today, emerged in the mid 20th century. It can be traced to the year of 1952, the U.S. Air Force, and the names of John Parsons and the Massachusetts Institute of Technology in Cam-bridge, MA, USA. It was not applied in production manu-facturing until the early 1960's. The real boom came in the form of CNC, around the year of 1972, and a decade later with the introduction of affordable micro computers. The history and development of this fascinating technology has been well documented in many publications.In the manufacturing field, and particularly in the area of metal working, Numerical Control technology has caused something of a revolution. Even in the days before comput-ers became standard fixtures in every company and in many homes, the2machine tools equipped with Numerical Control system found their special place in the machine shops. The recent evolution of micro electronics and the never ceasing computer development, including its impact on Numerical Control, has brought significant changes to the manufacturing sector in general and metalworking in-dustry in particular.DEFINITION OF NUMERICAL CONTROLIn various publications and articles, many descriptions have been used during the years, to define what Numerical Control is. It would be pointless to try to find yet another definition, just for the purpose of this handbook. Many of these definitions share the same idea, same basic concept, just use different wording.The majority of all the known definitions can be summed up into a relatively simple statement:Numerical Control can be defined as an operation of machine tools by the means of specifically coded instructions to the machine control systemThe instructions are combinations of the letters of alpha-bet, digits and selected symbols, for example, a decimal point, the percent sign or the parenthesis symbols. All in-structions are written in a logical order and a predetermined form. The collectionNUMERICAL CONTROLof all instructions necessary to ma-chine a part is called an NC Program, CNC Program, or a Part Program. Such a program can be stored for a future use and used repeatedly to achieve identical machining re-sults at any time.♦ NC and CNC TechnologyIn strict adherence to the terminology, there is a differ-ence in the meaning of the abbreviations NC and CNC. The NC stands for the older and original Numerical Control technology, whereby the abbreviation CNC stands for the newer Computerized Numerical Control technology, a modem spin-off of its older relative. However, in practice, CNC is the preferred abbreviation. To clarify the proper us-age of each term, look at the major differences between the NC and the CNC systems.Both systems perform the same tasks, namely manipula-tion of data for the purpose of machining a part. In both cases, the internal design of the control system contains the logical instructions that process the data. At this point the similarity ends. The NC system (as opposed to the CNC system) uses a fixed logical functions, those that are built-in and perma-nently wired within the control unit. These functions can-not be changed by the programmer or the machine opera-tor. Because of the fixed4wiring of the control logic, the NC control system is synonymous with the term 'hardwired'. The system can interpret a part program, but it does not al-low any changes to the program, using the control features. All required changes must be made away from the control, typically in an office environment. Also, the NC system re-quires the compulsory use of punched tapes for input of the program information.The modem CNC system, but not the old NC system, uses an internal micro processor (i.e., a computer). This computer contains memory registers storing a variety of routines that are capable of manipulating logical functions. That means the part programmer or the machine operator can change the program on the control itself (at the ma-chine), with instantaneous results. This flexibility is the greatest advantage of the CNC systems and probably the key element that contributed to such a wide use of the tech-nology in modern manufacturing. The CNC programs and the logical functions are stored on special computer chips, as software instructions, rather than used by the hardware connections, such as wires, that control the logical func-tions. In contrast to the NC system, the CNC system is syn-onymous with the term 'softwired'.NUMERICAL CONTROLWhen describing a particular subject that relates to the numerical control technology, it is customary to use either the term NC or CNC. Keep in mind that NC can also mean CNC in everyday talk, but CNC can never refer to the older technology, described in this handbook under the abbrevia-tion ofNC. The letter 'C 'stands for Computerized, and it is not applicable to the hardwired system. All control systems manufactured today are of the CNC design. Abbreviations such as C&C or C'n 'C are not correct and reflect poorly on anybody that uses them.CONVENTIONAL AMD CNC MACHININGWhat makes the CNC machining superior to the conven-tional methods? Is it superior at all? Where are the main benefits? If the CNC and the conventional machining pro-cesses are compared, a common general approach to ma-chining a part will emerge: Obtain and study the drawingSelect the most suitable machining methodDecide on the setup method (work holding)Select the cutting toolsEstablish speeds and feedsMachine the part6This basic approach is the same for both types of machin-ing. The major difference is in the way how various data are input. A feedrate of 10 inches per minute (10 in/min) is the same in manual or CNC applications, but the method of applying it is not. The same can be said about a coolant - it can be activated by turning a knob, pushing a switch or programming a special code. All these actions will result in a coolant rushing out of a nozzle. In both kinds of machin-ing, a certain amount of knowledge on the part of the user is required. After all, metal working, particularly metal cut-ting, is mainly a skill, but it is also, to a great degree, an art and a profession of large number of people. So is theappli-cation of Computerized Numerical Control. Like any skill or art or profession, mastering it to the last detail is neces-sary to be successful. It takes more than technical knowl-edge to be a CNC machinist or a CNC programmer. Work experience and intuition, and what is sometimes called a 'gut-feel', is a much needed supplement to any skill.In a conventional machining, the machine operator sets up the machine and moves each cutting tool, using one or both hands, to produce the required part. The design of a manual machine tool offers many features that help the process of machining a part -NUMERICAL CONTROLlevers, handles, gears and di-als, to name just a few. The same body motions are re-peated by the operator for every part in the batch. However, the word 'same 'in this context really means'similar 'rather than 'identical'. Humans are not capable to repeat every process exactly the same at all times - that is the job ofma-chines. People cannot work at the same performance level all the time, without a rest. All of us have some good andsome bad moments. The results of these moments, when*applied to machining a part, are difficult to predict. There will be some differences and inconsistencies within each batch of parts. The parts will not always be exactly the same. Maintaining dimensional tolerances and surface fin-ish quality are the most typical problems in conventional machining. Individual machinists may have their own time 'proven' methods, different from those of their fellow col-leagues. Combination of these and other factors create a great amount of mconsistency.The machining under numerical control does away with the majority of inconsistencies. It does not require the same physical involvement as manual machining. Numerically controlled machining does not need any levers or dials or handles, at least8not in the same sense as conventional ma-chining does. Once the part program has been proven, it can be used any number of times over, always returning consistent results. That does not mean there are no limiting factors. The cutting tools do wear out, the material blank in one batch is not identical to the material blank in another batch, the setups may vary, etc. These factors should be considered and compensated for, whenever necessary.The emergence of the numerical control technology does not mean an instant, or even a long term, demise of all man-ual machines. There are times when a traditional machin-ing method is preferable to a computerized method. For ex-ample, a simple one time job may be done more efficiently on a manual machine than a CNC machine. Certain types of machining jobs will benefit from manual or semiauto-matic machining, rather than numerically controlled ma-chining. The CNC machine tools are not meant to replace every manual machine, only to supplement them.In many instances, the decision whether certain machin-ing will be done on a CNC machine or not is based on the number of required parts and nothing else. Although the volume of partsNUMERICAL CONTROLmachined as a batch is always an important criteria, it should never be the only factor. Consideration should also be given to the part complexity, its tolerances, the required quality of surface finish, etc. Often, a single complex part will benefit from CNC machining, while fifty relatively simple parts will not.Keep in mind that numerical control has never machined a single part by itself. Numerical control is only a process or a method that enables a machine tool to be used in a pro-ductive, accurate and consistent way.NUMERICAL CONTROL ADVANTAGESWhat are the main advantages of numerical control?It is important to know which areas of machining will benefit from it and which are better done the conventional way. It is absurd to think that a two horse power CNC mill will win over jobs that are currently done on a twenty times more powerful manual mill. Equally unreasonable are ex-pectations of great improvements in cutting speeds and feedrates over a conventional machine. If the machining and tooling conditions are the same, the cutting time will be very close in both cases.Some of the major areas where the CNC user can and should expect improvement:10Setup time reductionLead time reductionAccuracy and repeatabilityContouring of complex shapesSimplified tooling and work holdingConsistent cutting timeGeneral productivity increaseEach area offers only a potential improvement. Individ-ual users will experience different levels of actual improve-ment, depending on the product manufactured on-site, the CNC machine used, the setup methods, complexity of fixturing, quality of cutting tools, management philosophy and engineering design, experience level of the workforce, individual attitudes, etc.Setup Time ReductionIn many cases, the setup time for a CNC machine can be reduced, sometimes quite dramatically. It is important to realize that setup is a manual operation, greatly dependent on the performance of CNC operator, the type of fixturing and general practices of the machine shop. Setup time is unproductive, but necessary - it is a part of the overhead costs of doing business. To keep the setupNUMERICAL CONTROLtime to a mini-mum should be one of the primary considerations of any machine shop supervisor, programmer and operator. Because of the design of CNC machines, the setup time should not be a major problem. Modular fixturing, standard tooling, fixed locators, automatic tool changing, pallets and other advanced features, make the setup time more efficient than a comparable setup of a conventional machine. With a good knowledge of modern manufacturing, productivity can be increased significantly.The number of parts machined under one setup is also important, in order to assess the cost of a setup time. If a great number of parts is machined in one setup, the setup cost per part can be very insignificant. A very similar re-duction can be achieved by grouping several different oper-ations into a single setup. Even if the setup time is longer, it may be justified when compared to the time required to setup several conventional machines.Lead Time ReductionOnce a part program is written and proven, it is ready to be Bsed again in the future, even at a short notice. Although the lead time for the first run is usually longer, it is virtually nil for any subsequent run. Even if an engineering change of the part design12requires the program to be modi tied, it can be done usually quickly, reducing the lead time.Long lead time, required to design and manufacture sev-eral special fixtures for conventional machines, can often be reduced by preparing a part program and the use of sim-plified fixturing. Accuracy and RepeatabilityThe high degree of accuracy and repeatability of modern CNC machines has been the single major benefit to many users. Whether the part program is stored on a disk or in the computer memory, or even on a tape (the original method), it always remains the same. Any program can be changed at will, but once proven, no changes are usually required any more. A given program can be reused as many times as needed, without losing a single bit of data it contains. True, program has to allow for such changeable factors as tool wear and operating temperatures, it has to be stored safely, but generally very little interference from the CNC pro-grammer or operator will be required. The high accuracy of CNC machines and their repeatability allows high quality parts to be produced consistently time after time. Contouring of Complex ShapesNUMERICAL CONTROLCNC lathes and machining centers are capable of con-touring a variety of shapes. Many CNC users acquired their machines only to be able to handle complex parts. A good examples are CNC applications in the aircraft and automo-tive industries. The use of some form of computerized pro-gramming is virtually mandatory for any three dimensional tool path generation.Complex shapes, such as molds, can be manufactured without the additional expense of making a model for trac-ing. Mirrored parts can be achieved literally at the switch of a button. Storage of programs is a lot simpler than storage of patterns, templates, wooden models, and other pattern making tools.Simplified Tooling and Work HoldingNonstandard and 'homemade' tooling that clutters the benches and drawers around a conventional machine can be eliminated by using standard tooling, specially designed for numerical control applications. Multi-step tools such as pilot drills, step drills, combination tools, counter borers and others are replaced with several individual standard tools. These tools are often cheaper and easier to replace than special and nonstandard tools.Cost-cutting measures have forced many tool suppliers to keep a low or even a nonexistent inventory, increasing the delivery lime14to the customer. Standard, off-the-shelf tooling can usually beob-tained faster then nonstandard tooling.Fixturing and work holding for CNC machines have only one major purpose - to hold the part rigidly and in the same position for all parts within a batch. Fixtures designed for CNC work do not normally require jigs, pilot holes and other hole locating aids.♦ Cutting Time and Productivity IncreaseThe cutting time on the CNC machine is commonly known as the cycle time - and is always consistent. Unlike a conventional machining, where the operator's skill, experi-ence and personal fatigue are subject to changes, the CNC machining is under the control of a computer. The small amount of manual work is restricted to the setup andload-ing and unloading the part. For large batch runs, the high cost of the unproductive time is spread among many parts, making it less significant. The main benefit of a consistent cutting time is for repetitive jobs, where the production scheduling and work allocation to individual machine tools can be done very accurately.The main reason companies often purchase CNCma-chines is strictly economic - it is a serious investment. Also, having a competitive edge is always on the mind of every plant manager. The numerical control teclmology offers excellent means to achieve a significant improvement in the manufacturing productivity and increasing the overall quality of the manufactured parts. Like any means, it has to be used wisely and knowledgeably. When more and more companies use the CNCtechnology, just having a CNC machine does not offer the extra edge anymore. Thecom-panies that get forward are those who know how to use the technology efficiently and practice it to be competitive in the global economy.To reach the goal of a major increase in productivity, it is essential that users understand the fundamental principles on which CNC technology is based. These principles take many forms, for example, understanding the electronic cir-cuitry, complex ladder diagrams, computer logic, metrol-ogy, machine design, machining principles and practices and many others. Each one has to be studied and mastered by the person in charge. In this handbook, the emphasis is on the topics that relate directly to the CNC programming and understanding the most common CNC machine tools, the Machining Centers and the lathes (sometimes also called the Turning Centers). The part quality consideration should be very important to every programmer and ma-chine tool operator and this goal is also reflected in the handbook approach as well as in the numerous examples.TYPES OF CNC MACHINE TOOLSDifferent kinds of CNCmachines cover an extremelylarge variety. Their numbersare rapidly increasing, as thetechnology developmentadvances. It is impossible toiden-tify all the applications,they would make a long list.Here is a brief list of some ofthe groups CNC machines canbe part of: *Mills and Machining centersLathes and Turning CentersDrilling machines CNC machining centers andlathes dominate the number ofinstallations in industry. Thesetwo groups share the marketjust about equally. Someindustries may have a higherneed for one group ofmachines, depending on their □ Boring mills and Profilers □ EDM machines □ Punch presses and Shears □ Flame cutting machines □ Routers □ Water jet and Laser profilers □ Cylindrical grinders □ Welding machines □ Benders, Winding and Spinning machines, etc.needs. One must remember that there are many different kinds of ladies and equally many different kinds ofma-chining centers. However, the programming process for a vertical machine is similar to the one for a horizontalma-chine or a simple CNC mill. Even between differentma-chine groups, there is a great amount of general applica-tions and the programming process is generally the same. For example, a contour milled with an end mill has a lot in common with a contour cut with a wire.♦ Mills and Machining Centers Standard number of axes on a milling machine is three - the X, Y and Z axes. The part set on a milling system is al-ways stationary, mounted on a moving machine table. The cutting tool rotates, it can move up and down (or in and out), but it does not physically follow the tool path.CNC mills - sometimes called CNC milling machines - are usually small, simple machines, without a tool changer or other automatic features. Their power rating is often quite low. In industry, they are used for toolroom work, maintenance purposes, or small part production. They are usuallydesigned for contouring, unlike CNC drills.CNC machining centers are far more popular and effi-cient than drills and mills, mainly for their flexibility. The main benefit the user gets out of a CNC machining center is the ability to group several diverse operations into a single setup. For example, drilling, boring, counter boring, tap-ping, spot facing and contour milling can be incorporated into a single CNC program. In addition, the flexibility is enhanced by automatic tool changing, using pallets to minimize idle time, indexing to a different side of the part, using a rotary movement of additional axes, and a number of other features. CNC machining centers can be equipped with special software that controls the speeds and feeds, the life of the cutting tool, automatic in-process gauging and offset adjustment and other production enhancing and time saving devices.There are two basic designs of a typical CNC machining center. They are the vertical and the horizontal machining centers. The major difference between the two types is the nature of work that can be done on them efficiently. For a vertical CNC machining center, the most suitable type of work are flat parts, either mounted to the fixture on the ta-ble, or held in a vise or a chuck. The work that requires ma-chining on two or more faces m a single setup is more de-sirable to be done on a CNC horizontal machining center. An good example is a pump housing and other cubic-like shapes. Some multi-face machining of small parts can also be done on a CNC vertical machining center equipped with a rotary table.The programming process is the same for both designs, but an additional axis (usually a B axis) is added to the hori-zontal design. This axis is either a simple positioning axis (indexing axis) for the table, or a fully rotary axis for simul-taneous contouring. This handbook concentrates on the CNC vertical ma-chining centers applications, with a special section dealing with the horizontal setup and machining. The program-ming methods are also applicable to the small CNC mills or drilling and/or tapping machines, but the programmer has to consider their restrictions.♦ Lathes and Turning CentersA CNC lathe is usually a machine tool with two axes, the vertical X axis and the horizontal Z axis. The main feature of a lathe that distinguishes it from a mill is that the part is rotating about the machine center line. In addition, the cut-ting tool is normally stationary, mounted in a sliding turret. The cutting tool follows the contour of the programmed tool path. For the CNC lathes with a milling attachment, so called live tooling, the milling tool has its own motor and rotates while the spindle is stationary.The modem lathe design can be horizontal or vertical. Horizontal type is far more common than the vertical type, but both designs have their purpose in manufacturing. Sev-eral different designs exist for either group. For example, a typical CNC lathe of the horizontal group can be designed with a flat bed or a slant bed, as a bar type, chucker type or a universal type. Added to these combinations are many ac-cessories that make a CNC lathe an extremely flexible ma-chine tool. Typically, accessories such as a tailstock, steady rests or follow-up rests, part catchers,pullout-fingers and even a third axis milling attachment are popular compo-nents of the CNC lathe. ?CNC lathe can be veiy versatile - so versatile in fact, that it is often called a CNC TurningCenter. All text and program examples in this handbook use the more traditional term CNC lathe, yet still recogniz-ing all its modern functions.中文翻译:数控正如我们现在所知,数控技术出现于20世纪中叶。

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本科毕业设计(论文)外文翻译题目高层建筑结构探索—住宅3学院建工学院专业土木工程班级09土木本一学号09 (35)学生姓名……指导教师……温州大学教务处制外文原文Building Materials Selection andSpecificationFae'q A. A. RadwanFaculty of Engineering, Near East University, KKTC, Lefkosa, Mersin 10, Turkey Abstract:The limitations in the selection of the building materials and to the sustainability of any building construction materials that can be used are presented. The practices and techniques that can be used in reducing and minimizing the environmental impacts of building are discussed. Recommendations of using secondary and recycled materials in the construction of buildings are given. Framework for methods of assessment of the sustainability in building construction for environmental performance is presented.Key Words:Limitations, sustainability, environmental impacts, framework, climate.1.IntroductionThere is an apparently unbounded range of possibilities for the selection of building materials for the construction of structures of almost any shape or stature. Its quality will affect the structure function and long life, and requirements may differ with climate, soil, site size, and with the experience and knowledge of the designer. The factors that , manufacturing processes, and the transportation of the materials to the project site the environment. These include the disruption of the building occupants manufacture, construction of buildings and the use of building materials make a significant environmental impact internally, locally and globally. But it is not easy to deliver information to make adequate inclusion decisions considering the whole life cycle of a building. Decisions on sustainable building integrate a number of strategies during the design, construction and operation of building projects. Selection of sustainable building materials represents an important strategy in the design of a building.2. SustainabilityIn recent years, the concept of sustainability the subject of much disputation by academics and professionals alike. In 1987, the World Conference on Environment and Development defined sustainable development as development that meets the needs of the present without compromising the ability of future generations to meet their own needs(WCED, 1987).Sustainability must address ecological impacts, regardless of conflicting interpretations of the WCED definition.A good sustainable product must give as much satisfaction as possible for the user. If not, it will be unsuccessful on the market and an economic failure.It is also important to inform people as to what basis a certain product is considered to be sustainable or not and why they should buy it [4- 5].When developing a new product, it is illustrative to move between the three corners Ecology, Equity and Economy in order to obtain a suitable balance so that each category can be fulfilled in the best way.·Ecology (environmental protection).·Equity (social equity).·Economy (economic growth).2.1 Materials Selection and SustainabilityAmong the notable technological developments of the 20th century the development of tens of thousands of new materials for use in construction and engineering. The construction industry to the point where it is a very large consumer of energy and materials. Concern for the environment and the impact of activity on the Earth's ecological systems and the environmental consequences of their use. Environmentalists dioxide values, and so on. Engineers methods for the choice of materials. These techniques will be reviewed and explored in an attempt to provide an environmentally-aware, materials selection method- logy for use in construction.Strictly, the term sustainable means that something is capable of beingsustained not for an is that if some process which uses materials and energy is described as sustainable, then the materials and energy which are consumed are capable of being replaced by natural or other processes as fast as they are consumed. In many cases materials and energy appear to be consumed at a faster rate than they are being replaced. However, to make a judgment, we would need to know what the respective supply and consumption rates are in other words we need some quantitative or numerical index to uses such large quantities of materials, it the environment. In order to assess and evaluate such impact, a number of criteria or indices devised by economists, engineers and environmentalists, and the more important of these are the following [2].2.2.1 Embodied EnergyThis is quite simply the amount of energy consumed in manufacturing a unit quantity of a material, and it is usually expressed in kJkg. Its value is determined by the efficiency of the manufacturing plant. Values range from 275 GJtonne for aluminum (a DioxideEmbodied C02 is similar to embodied energy. It is the weight of C02 emitted during manufacture of unit weight of the material, and is usually expressed as kg of C02 per ton.Again, the value will depend upon the efficiency of the manufacturing plant [2].2.2.3 Ecological RucksackThe ecological rucksack concept was devised as a way of assessing material efficiency by F. Schmidt一Bleek [6]. He recognized that many tonnes of raw material could be extracted and processed to make just one kilogram of material. For example, the environmental rucksack for2.3 Rational Selection MethodThere are various approaches to the problem of selecting materials from the talk to their colleagues, previous, similar designs. All these are valid approaches, but they may result in the specification of a less than ideal material and overall, a less than optimal solution to the problem [3-5].The basis of the rational selection methods devised to date is a recognition that the performance of a component, artifact or structure is limited by the properties of the materials from which it is made. It will be rare for the performance of the item to depend solely on one material property; in nearly all cases, it is a combination of properties, which is important. To give an example, in lightweight design, strength to weight ratio of, and stiffness to weight ratio Epwill be important. Ref. [3] these maps, each class of material occupies a field in material property space, and sub-fields map the space occupied by individual materials.These materials property charts are very information-rich they carry a large amount of information in a compact but accessible form. Interestingly, they reveal correlations between material properties, which can checking and estimating data, and they can also be used in performance optimization, in a manner such as that set out as follow.If we consider the complete range of materials, it immediately becomes apparent that for each property of an engineering material there is a characteristic range of values, and this range can be very large. For example, consider stiffness (Young's Modulus E). Materials range from jelly (very low stiffness) up to diamond (very span five decades (orders of magnitude),A number of conclusions can be drawn, including:(1) A rational selection method such the one put forward by Ashby is capable of incorporating environmental parameters such as embodied energy and C02 or the environmental rucksack concepts, thereby making possible rational selections based on environmental considerations.(2) This method is not as simple to use as the environmental preference method or the environmental profiles method. However, this rational method could be used to generate data for the environmental profiles and preference methods.(3) The construction industry needs to take steps to better integrate itself into the materials cycle. The quantity of demolition waste needs to be reduced, and more of it should be recycled. To this end, the building designers need to keep full records of materials of construction, and buildings need to be designed for easy dismantling at the end of their useful lives.3. Foundations and Construction ComponentIn any consideration of which building materials and alternatives can feasibly be integrated into the foundations of a large-scale development there are several limitations that must be considered.In terms of the actual materials that may be used, there are three main limitations. First, because of the large scale and is climate. In areas with sub-zero winter conditions, frost . For this reason, foundations must be deep enough to support the structure despite any changes in near-surface volume; shallow foundations will be insufficient unless certain innovative steps are taken. The limitation of climate also influences any decision oninsulating foundations. Finally, there is the consideration of cost. This consideration is reliant on material availability, cost per unit, and building techniques and associated labor. For these reasons, the only materials that can feasibly be used are concrete and steel. Therefore, the alternatives for minimizing impact lie more in the methods of construction and any realistic structural changes that can be made.The three main foundation components of concrete, steel, and insulation will be examined as the only reasonable materials for the construction of a building with limitations such as the foundations [1].3.1 ConcreteIt is the fundamental component of the foundation construction, receiving the building loads through walls or posts and distributes them down and outwards through the footings. Concrete and cement general) chemical inertness [8]. The life cycle concerns of concrete are as follows. First, there is land and , transportation, and manufacture. Carbon dioxide emissions are also a negative environmental impact accrued through the production and use of concrete. Similarly, dust and particulate are emitted at most stages of the concrete life-cycle. $oth carbon dioxide and particulate matter air quality [1]. Water pollution is also another concern associated with the production of concrete at the production phase. Fly ash is by-product of the energy production from coal-fired plants and increasing its proportion in cement is environmentally beneficial in two ways. First, it reducing the amount of solid waste which requires disposal. As well, fly ash in the cement mixture reduced the overall energy use by changing the consistency of the concrete. Fly ash, increases concretestrength, improves sulfate foundation, decreases permeability, reduced the water ratio required, and improves the pump ability and workability of the concrete [9]. Now in the United States, the Environmental Protection Agency requires that all buildings that receive federa funding contain fly ash and most concrete producer: of fly ash into the cement mixture, and the use of pre-cast foundation systems to reduce resource use. Through consideration and possible integration of these alternatives, impacts could potentially be reduced.3.2 SteelAs wood resources are becoming limited, steel is increasingly popular with builders. In the case of a large-scale building, steel reinforcement is basically a necessity for overall strength and weight distribution.The initial life cycle impacts of steel use are similar to those of concrete. These include land and from materials acquisition and manufacture [1]. However, the largest proportion of steel used nowadays contains a percentage of recycled materials. In terms of improving environmental conditions by reducing impacts, this is the only real recommendation for the use of steel in building foundations; to purchase recycled steel products. Not only would this reduce industrial and commercial solid waste, such a decision would also reward the manufacturers of such products.3. 3 InsulationNew and innovative pre-cast building foundations are becoming increasingly available and feasible for implementation. These new systems can reduce the overall raw material use, as well as conserve energy throughthe creation of an efficient building envelope. A further used of this rigid insulation as a skirt around the building foundations systems is increased. Also, in soils where frost and drainage is a consideration additional piles in the centre of the foundation may be required to prevent movement. This increases the relative land disturbance, although it remains still much less than that of deep foundation systems. Shallow foundations are structurally sound and are becoming increasingly common in colder climates. There are strength considerations associated with these new techniques which must be addressed by someone with the technical ability to do so, before they can be feasibly recommended for the building of the new residence.As discussed above, there are limitations to the sustainability of any foundation construction materials used. In other words, there are environmental impacts associated with all types of foundations. For these reasons, a primary recommendation is the use of secondary materials (fly ash and recycled steel) in the construction of foundations.4. FrameworkThe material components of the building envelope, that is, the foundation, wall construction, insulation and roof, analyzed within a framework of primarily qualitative criteria that aim to evaluate the sustainability of alternate materials relative to the materials cited in the current foundation design. This analytical process of several construction materials that can be feasibly integrated into current design and construction standards of the building envelope.The tools and strategies described below are useful in analyzing therelative benefits of different materials[9-14].Life-Cycle Assessment (LCA). LCA is a comprehensive analysis that takes into consideration all aspects of a material over its entire lifetime: raw materials extraction; manufacturing and processing; transport; use; and post-use recycling, reuse, or disposal. This approach enables a true "apples to apples" comparison between materials.The BEES system (Building for Environmental and Economic Sustainability) developed by the National Institute of Standards and Technology is the most widely used methodology. BEES provides materials with a score that can be compared to other similar products. At this time, analysis of the short- and long-term costs associated with a material, from purchase to ultimate recycling or disposal. This includes frequency of replacement, maintenance costs, and costs that are avoided through use of the material (or system). LCC is useful in looking beyond a comparison based solely on first costs. Similar to LCA, this type of analysis is not available for all materials, but a back-of-the-envelope calculation is usually fairly easy to work up.Certification. Many conventional building products are approved or certified by independent third party or government groups. The Forest Stewardship Council certifies the certifiers (Smart Wood and SCS) that assess whether forestry companies are using sustainable management practices to Label for carpets that meet certain low-VOC criteria. Green Guard certifies products that meet strict indoor air quality criteria. The Department of Energy's Energy Star label identifies equipment and appliances that meet or exceed standards for energy efficiency. ScientificCertification Systems and Green Seal certify recycled-content claims and other green product claims made by manufacturers.5. ConclusionOver-consumption, resource utilization, pollution and over-population are examples of the perhaps most basic problems for the environment in the future. A more sustainable future can be achieved by producing more sustainable products causing less environmental impact. Materials and design are and will always be very important areas when developing more sustainable products.The Life Cycle Assessment concept might be the most effective way of determining the environmental impacts for all product stages from extract of material to the product disposal stage. A price must be set for restoration on every environmental impact. Information can be received from official authorities pertaining to the environment in different countries. Renewable and easy recyclable materials are preferably used together with a design for easy recycling and repair of the products. Minimization of the energy connected to the product is also important. Full sustainability can never be achieved for products according to thermodynamic laws. However, the attempt to achieve more sustainability is a requisite if we want to preserve the earth for the coming generations. Education, research and spreading of information will be very important for the future in order to receive more sustainable products especially because the market demand is important in order to develop successful sustainable products.References[1] M. Davison, J. Persmann, J. Reid, J. Stange and T. Weins, Green Building Materials Residence, A WATgreenERS 285 study.[2] J. L. Sturges, Construction Materials Selection and Sustainability, School of the Built Environment, Leeds Metropolitan University, UK.[3] M. F. Ashby, Materials Selection in Mechanical Design, Pergamon, Oxford, 1992.[4] M. F. Ashby and K. Johnson, Materials and Design: The Art And Science of Materials Selection in Product Design, Oxford: Butterworth-Heinemann, 2002[5] L. Y. Ljungberg, Materials selection and design for development of sustainable products, [6] F. Berkhout and D. Smith, Products and the environment: an integrated approach to policy, [7] F. Schmidt-Bleek, Carnoules Declaration of the FactorTen Club, Wuppertal Institute, Germany, 1994.[8] A.Wilson,Building green on a budget,Environmental Building News8(5)(1999).[9] G.E.Dieter,Engineering Design,McGraw-Hill,New York,l991.[10] Sandy Patience (Ed.),The Role of Evidence in The Selection of Building Products and Materials,Constructing Excellence in The Built Environment.[11] M.D.Bovea and R.Vidal,Increasing product value by integrating environmental impacts [12] N.S.Ermolaeva,M.B.G.Castro and P.V.Kandachar, Materials selection for an automotive structure by integrating structural optimization with environmental impact assessment,Materials and Design 25 (2004) 689.698.[13] M.Goedkoop and R.Spiensma,The Eco-Indicator 99:A Dam age Oriented Method for Life Cycle Impact Assessment,Amersfooft:PRe consultant B.V.,2000.中文翻译建筑材料的选择和规格Fae'q A. A. RadwanFaculty of Engineering, Near East University, KKTC, Lefkosa, Mersin 10, Turkey 摘要:建筑材料选择的局限性和可利用的建筑建设材料的可持续发展问题已经呈现出来,可以减少和降低建筑对坏境影响的实践经验和技术已经给出。

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