毕业设计中英文翻译

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采矿工程毕业设计_外文翻译英译汉中英文

ROOM-AND-PILLAR METHOD OF OPEN-STOPE MINING空场采矿法中的房柱采矿法Chapter 1.A Classification of the Room-and-Pillar Method of Open-Stope Mining第一部分，空场采矿的房柱法的分类OPEN STOPING空场采矿法An open stope is an underground cavity from which the initial ore has been mined. Caving of the opening is prevented (at least temporarily) by support from the unmined ore or waste left in the stope,in the form of pillars,and the stope walls (also called ribs or abutments). In addition to this primary may also be required using rockbolts , reinforcing rods, split pipes ,or shotcrete to stabilize the rock surface immediately adjacent to the opening. The secondary reinforcement procedure does not preclude the method classified as open stoping.露天采场台阶是开采了地下矿石后形成的地下洞室。

通过块矿或采场的支柱和（也称为肋或肩）采场墙形式的废料的支持来（至少是暂时的）预防放顶煤的开幕。

除了这个，可能还需要使用锚杆，钢筋棒，分流管，或喷浆，以稳定紧邻开幕的岩石表面。

办公楼毕业设计英文翻译(外文翻译)

办公楼毕业设计英文翻译（外文翻译）原文：The future of the tall buildingAnd structure of buildingsZoning effects on the density of tall buildings and solar design may raise ethical challenge.A combined project of old and new buildings may bring back human scale to our cities. Owners and conceptual designers will be challenged in the 1980s to produce economically sound, people-oriented buildings.In 1980 the Level House, designed by Skidmore, Owings and Merril1 (SOM) received the 25-year award from the American Institut e of Architects “in recognition of architectural design of enduring significance”. This award is given once a year for a building between 25and 35 years old .Lewis Mumford described the Lever House as “the first office building in which modern materials, m odern construction, modern functions have been combined with a modern plan”. At the time, this daring concept could only be achieved by visionary men like Gordon Bunshaft , the designer , and Charles Luckman , the owner and then-president of Lever Brothers . The project also included a few “first” : (1) it was the first sealed glass tower ever built ; (2) it was the first office building designed by SOM ;and (3) it was the first office building on Park Avenue to omit retail space on the first floor. Today, after hundreds of look-alike and variations on the grid design, we have reached what may be the epitome of tall building design: the nondescript building. Except for a few recently completed buildings that seem to be people-oriented in their lower floors, most tall buildings seem to be a repletion of the dull, graph-paper-like monoliths in many of our cities. Can this be the end of the design-line for tall buildings? Probably not. There are definite signs that are most encouraging. Architects and owners have recently begun to discuss the design problem publicly. Perhaps we are at the threshold of a new era. The 1980s may bring forth some new visionaries like Bunshaft and Luckman. If so, what kinds of restrictions or challenges do they face?译文：高层建筑展望及建筑结构区域规划对高层建筑物的密度和对自然采光设计可能引起道德问题将产生影响。

毕业设计中英文翻译

本科生毕业设计（论文）外文翻译毕业设计（论文）题目：电力系统检测与计算外文题目：The development of the single chipmicrocomputer译文题目：单片机技术的发展与应用学生姓名： XXX专业： XXX指导教师姓名： XXX评阅日期：单片机技术的发展与应用从无线电世界到单片机世界现代计算机技术的产业革命，将世界经济从资本经济带入到知识经济时代。

在电子世界领域，从 20 世纪中的无线电时代也进入到 21 世纪以计算机技术为中心的智能化现代电子系统时代。

现代电子系统的基本核心是嵌入式计算机系统(简称嵌入式系统)，而单片机是最典型、最广泛、最普及的嵌入式系统。

一、无线电世界造就了几代英才。

在 20 世纪五六十年代，最具代表的先进的电子技术就是无线电技术，包括无线电广播，收音，无线通信(电报)，业余无线电台，无线电定位，导航等遥测、遥控、遥信技术。

早期就是这些电子技术带领着许多青少年步入了奇妙的电子世界，无线电技术展示了当时科技生活美妙的前景。

电子科学开始形成了一门新兴学科。

无线电电子学，无线通信开始了电子世界的历程。

无线电技术不仅成为了当时先进科学技术的代表，而且从普及到专业的科学领域，吸引了广大青少年，并使他们从中找到了无穷的乐趣。

从床头的矿石收音机到超外差收音机；从无线电发报到业余无线电台；从电话，电铃到无线电操纵模型。

无线电技术成为当时青少年科普、科技教育最普及，最广泛的内容。

至今，许多老一辈的工程师、专家、教授当年都是无线电爱好者。

无线电技术的无穷乐趣，无线电技术的全面训练，从电子学基本原理，电子元器件基础到无线电遥控、遥测、遥信电子系统制作，培养出了几代科技英才。

二、从无线电时代到电子技术普及时代。

早期的无线电技术推动了电子技术的发展，其中最主要的是真空管电子技术向半导体电子技术的发展。

半导体电子技术使有源器件实现了微小型化和低成本，使无线电技术有了更大普及和创新，并大大地开阔了许多非无线电的控制领域。

毕业设计中英文翻译

英文The road (highway)The road is one kind of linear construction used for travel. It is made of the roadbed, the road surface, the bridge, the culvert and the tunnel. In addition, it also has the crossing of lines, the protective project and the traffic engineering and the route facility.The roadbed is the base of road surface, road shoulder, side slope, side ditch foundations. It is stone material structure, which is designed according to route's plane position .The roadbed, as the base of travel, must guarantee that it has the enough intensity and the stability that can prevent the water and other natural disaster from corroding.The road surface is the surface of road. It is single or complex structure built with mixture. The road surface require being smooth, having enough intensity, good stability and anti-slippery function. The quality of road surface directly affects the safe, comfort and the traffic.The route marking is one kind of traffic safety facility painted by oil paint or made by the concrete and tiles on high-level, less high-type surface. Its function is coordinating the sign to make the effective control to the transportation, directing the vehicles skip road travel, serving unimpeded and the safe purpose. Our country’s road route marking has the lane median line, the traffic lane boundary, the curb line, the parking line, the conduction current belt, the pedestrian crossing line, the four corners center circle, the parking azimuth line. The route marking has the continual solid line, the broken line and the arrow indicator and its color uses the white or the yellow.The arch of bridge is the structure which strides over rivers, mountain valley and channel. It is made generally by steel rod, concrete and stone.The tunnel is the cave which connects both sides of the road. The technique of this construction is very complex, the cost of the projects is higher than common road .However, it reduces the driving distance between two places, enhances the grade of the technical in building the road and guarantees the cars can drive fast and safely, thus reduces the cost of transportation.The protective project is to protect and consolidate the roadbed in order that it can guarantee the intensity and the stability of the road, thus maintains the automobile to pass through safely.In order to guarantee that safe operation of the highway transportation, besides the highway engineering and the vehicles performance, it must have some traffic signal, route marking, each kind of director and demonstrate facility. The highway marking uses certain mark and draw symbol, simple words and number, then installs in the suitable place to indicate the front road's condition or the accident condition including the informational sign, the warning signal, the prohibitory sign, the road sign and so on.The road which Join city, village and industry, mainly are used for the automobile and has certain technical standard and the facility path can be called the highway. “The highway” in Chinese is the modern view, but it was not existed in old day. It gets the name from the meaning of being used for the public traffic. Where are the human, there are the road. It is a truth. However, the road is not the highway. If we talk the history about the road, the earliest highway is that built by the old Egyptians for making the pyramid. Next is the street which built by the Babylon people about 4000 years ago. All these are much earlier than our country.About 500 B.C., the Persian Empire road has linked up East and West, and connected the road to China. It is the earliest and longest Silk Road. 2500 years ago, it might be the greatestroad .The ancient Rome Empire’s road was once celebrated; it took Rome as the center, all around built 29 roads. Therefore it came out one common saying: every road leads to Rome.The road's construction is the process to enhance technique and renew the building materials. The earliest is the old road, it is easy to build but it is also to destroy. If there is too much water or cars, it will be uneven and even be destroyed. The macadam road appeared in the Europe which outbalanced the earliest mud road. Then the brick road appeared which was earlier than China. It was one great breach that we molded bitumen on the macadam road. From ancient times to the present, China has courier station and courier road, while the first more advance road was the one that from Long Zhou in Gang Xi to Zhen Nan Guan in 1906.The difference between Road and pathThe path is the project for each kind of vehicles and people to pass through. According to its function, we can divide it into the urban road, the road, the factories and mines path, the forest road and county road.The classification of roadFirst, according to administrative rank, it includes national highway, province road, county road and the special road. Generally the national highway and province road are named main line; the county road is named branch line.The national road is the main line and has political and economy significance, including the important national defense road and the road collecting our capital with other provinces, autonomous regions and municipalities. It is also the road links the economy center, seaport hinge, factory and important strategic place. The highway striding over different provinces are built, protected and managed by the special organizations which are approved by the ministry of communications.The provincial road is the main line built, protected, managed by the road manage department .It is full of political and economic sense to the whole province.The single way four levels of roads can adapt below each day and night medium-duty truck volume of traffic 200.The county route is refers to has county-wide (county-level city) politics,the econom-icsignificance, connects in the county and the county the main township (town), the prin-cipal commodities production and the collection and distribution center road, as well as does not belong to the federal highway, provincial road's county border the road. The coun-ty route by the county, the city road Department responsible for the work is responsibleto construct, the maintenance and the management.The township road refers to mainly the road which for the township (town) the villa-geeconomy,the culture, the administration serves, as well as does not belong to above t-hecounty route between road's township and the township and the township and the exte-rior contact road. Township is responsible by the people's government to construct, the m-aintenance and the management.The special-purpose road is refers to feeds specially or mainly supplies the factories andmines,the forest region, the farm, the oil field, the tourist area, the military importantplace and so on and the external relations road. The special-purpose road is responsibleby the special-purpose unit to construct, the maintenance and the management. May also entrust the local road department to construct, the maintenance and the management.Second, according to the use duty, the function and adapts the volume of traffic division.According to our country present "Highway engineering Technical standard" the roadaccording to the use duty, the function and the adaptation volume of tra-fficdivides into highway,arterial road, second-class road, tertiary highway, four level of road five ranks: 1st, the highway to feed specially the automobile and should control the difference c-ompletely respectively toward the dividing strip on roads travel the multiple highway.The four traffic lane highways ought to be able to adapt each kind of automobile reduce passenger vehicle's year mean diurnal volume of traffic 25000~55000.The six traffic lane highways ought to be able to adapt each kind of automobile reduce passenger vehicle's year mean diurnal volume of traffic 45000~80000.The eight traffic lane highways ought to be able to adapt each kind of automobile r-educe passenger vehicle's year mean diurnal volume of traffic 60000~100000.2nd, the arterial road to supply the automobile and may according to need to control the difference respectively toward the dividing strip on roads travel the multiple highway.The four traffic lane arterial roads ought to be able to adapt each kind of automobil reduce passenger vehicle's year mean diurnal volume of traffic 15000~30000.The six traffic lane arterial roads ought to be able to adapt each kind of automobile reduce passenger vehicle's year mean diurnal volume of traffic 25000~55000.3rd, the second-class road to supply the automobile travel the two-lane highway.Can adapt each day and nights 3000~7500 medium-duty truck volume of traffic generally.4rd, tertiary highways to mainly supply the automobile travel the two-lane highway.Can adapt each day and nights 1000~4000 medium-duty truck volume of traffic generally.The 5, four levels of roads to mainly supply the automobile travel the two-lane or the single-lane highway.The two-lane four levels of roads can adapt below each day and night medium-duty truck volume of traffic 1500.Highway engineering includes Highway planning location design and maintenance. Before the design and construction of a new highway or highway improvement can be undertaken there mint be general planing and consideration of financing As part of general planning it is decided what the traffic need of the rea will be for a considerable period, generally 20 years, and what construction will meet those needs. To assess traffic needs the highway engineer collects and analyzes information about the physical features of existing facilities, the volume, distribution, and character of present traffic, and the changes to be expected in these factor. The highway engineer must determine the most suitable location layout, and capacity of the new route and structures. Frequently, a preliminary line or location and several alternate routes are studied. The detailed design is normally begun only when the preferred location has been chosen.In selecting the best route, careful consideration is given to the traffic requirements terrain to be traversed value of land needed for the right-of-way. and estimated cost of construction for the various plans. The photogrammetric method, which makes use of aerial photographs is used extensively to indicate the character of the terrain on large projects where it is most economical. On small project,Financing considerations determine whether the project can be carried out t\t one time or whether construction must be in stages with each stage initiated as funds become available. In deciding the best method of financing the work, the engineer makes an analysis of whom it willbenefit. Important highways and streets benefit* in varying degrees, three groups* users owners of adjacent property and the general public.Users of improved highways benefit from decreased cost of transportation, greater travel comfort, increased safety and saving of time. They also obtain recreational and educational benefits. Owners of abutting or adjacent property may benefit from better access, increased property value, more effective police and fire protection, improved street parking greater pedestrian traffic safety, and the use of the street right-of-way for the location of public utilities such as water lines and sewers.Evaluation of various benefits from highway construction is often difficult but is a most important phase of highway engineering. Some benefits can be measured with accuracy, but the evaluation of others is more speculative. As a result numerous methods arc used to finance construction, and much engineering work may he involved in selecting the best procedure.Environmental evaluation. The environmental impact of constructing highways has received increased attention and importance. Many projects have been delayed and numerous others canceled because ot environmental problems. The environmental study or report covers many factors, including noise generation, air pollution disturbance of areas traversed destruction of existing housing and possible alternate routes.Highway engineers must also assist in the acquisition of right-of-way needed for new highway facilities Acquisition of the land required for construction of expressway lending into the central business areas of cities has proved extremely difficult i the public is demanding that traffic engineers work closely with c i t y planners, architects, sociologists and all groups interested in beautification and improvement of cities to assure that expressways extendinx through metropolitan areas be built only after coordinated evaluation of all major questions, including the following;(1) Is sufficient attention being paid -to beautification of the expressway itself? (2) Would a change in location preserve major natural beauties of the city? (3) Could a depressed design he logically substituted for those sections where an elevated expressway is proposed? (4) Can the general design he improved to reduce the noise created by large volumes of traffic? (5) Are some sections of the city being isolated by the proposed location?Detailed design. Detailed design of a highway project includes preparation of drawings or blueprints to be used for construction. These plans show, for example, the location, the dimensions of such elements as roudway width* the finaj pro (he road, the location and type of drainage facilities, and the quantities of work involved, including earthwork and surfacing.In planning the grading operations the design engineer considers the type of material to be encountered in excavating or in cutting away the high points along the project and how the rnaterial removed can best be utilised for fill or for constructing embankments across low areas elsewhere on the project. For this the engineer must analyze the gradation and physical properties of the soil, determine how the embankments can best be compacted, and calculate the volume of earthwork to be done. Electronic calculating procedures are now sometimes used for the last step. Electronic equipment has also speeded up many other highway engineering calculations. Powerful and highly mobile earth moving machines have been developed TO permit rapid and economical operations., Selection of the type and thickness of roudway surfacing to be constructed is an important part of design. The type chosen depends upon the maximum loads to be accommodated, thefrequency of these loads and other factors. For some mures, traffic volume may be so low that no surfacing is economically justified and natural soil serves as the roadway. As traffic increases, a surfacing of sandy cluy, crushed slag, crushed stone caliche crushed oyster shells, or a combination of these may be applied. If gravel is used, it usually contains sufficient clay and fine material to help stabilize the surfacing. Gravel surfaces may be further stubilized by application of calcium chloride, which also aids in controlling dust. Another surfacing is composed of Portland cement and water mixed iuto the upper few inches of the suhgrade and compacted with rollers. This procedure forms A soil-cement base that can be surfaced with bituminous materials. Roadways ro carry large volumes of heavy vehicles must be carefully designed and made of considerable thickness.Much of highway engineering is devoted to the planing and construction of facilities to drain the highway or street and lo carry streams across the highway right-of-way.Removal of surface water from the road or street is known a surface druiuage. It is accomplished by constructing the road so that it has a crown and by sloping the shoulders and adjacent areas so as to control the flow of water either toward existing natural drainage, such as open ditches, or into a storm drainage system of calehbasins and underground pipes. If a storm drainage system is used, as it would be with city streets, the design engineer must give consideration to the rntal area draining onto the street, the maximum rate of runoff expected, the duration of the design storm, the amount of ponding allowable at each carchbasin, and the proposed spacing of the catchbasins along the street. From this information the desired capacity of the individual eatehbaxin and the size of the underground piping network urc calculated. In designing facilities to carry streams under the highway the engineer must determine the area to be drained the maximum probable precipitation over the drainage basin, the highest expected runoff rare.and then, using (hit information, must calculate the required capacity of llit: drainage structure. Generally designs are made adequate to accommodate not only the largest flow ever recorded for that location but the greatest discharge that might be expected under the most adverse conditions for a given number of years.Factor considered in calculating the expected flow through a culvert opening include size, length, and shape of the opening, roughness of the walls, shape of t h e entrance and downstream end of the conduit, maximum allowable height of water at the entrance, and water level at the outletMuch engineering und construction work has been done to provide rest stops along major expressway routes t especially the national system of interstate highways. These facilities must be carefully located to permit easy and safe exit and return access to the highway. Many units have been built ^ scenic locations in forested areas to permit picnic grounds and walkways through the forest. These rest areas are especially beneficial to tho«e drivers traveling long distances with few stops.. The control and reduction of noise along busy routes, especially expressways, has become an important part of highway engineering. In many communities high walls have been huilt along either side of the expressway. Such walls can he costly to construct, hut can prove very beneficial, barriers can reduce overall noise levels by over 50%.Construction operations. Although much engineering and planing must be done preliminary to it, the actual construction is normally the costliest part of making highway uud street improvements.Willi t h e award of a construction contract following the preparation of the detailed plans and specifications t engineers go onto the ftite and lay out the project. As part of this staking out. limits of earthwork are shown, location of drainage structures indicated, and profiles established.Heavy rollers are used to compact the soil or subgrade below the roadway in order to eliminate later settlement. Pneumatic tired rollers and sheepsfoot rollers (steel cylinders equipped with numerous short steel teeth or feet J are often employed for this operation. Vibratory rollers have been developed and used on some projects in recent years. One type vibrates up to 3400 times/min, compacting the underlying material to an appreciable depth.Maintenance and operation. Highway maintenance consists of the repair and upkeep of surfacing and shoulders, bridges and drainage facilities? signs, traffic control devices, guard rails, traffic striping on the pavement, retaining walls, and side slopes. Additional operations include ice control und snow removal, because it is valuable to know why some highway designs give better performance and prove less costly to maintain than others, engineers supervising maintenance can offer valuable guidance to design engineers. Consequently, maintenance and operation arc important parts of highway engineering.中文公路是供汽车或其他车辆行驶的一种线形带状结构体。

毕业设计中英文翻译

Bridge Waterway OpeningsIn a majority of cases the height and length of a bridge depend solely upon the amount of clear waterway opening that must be provided to accommodate the floodwaters of the stream. Actually, the problem goes beyond that of merely accommodating the floodwaters and requires prediction of the various magnitudes of floods for given time intervals. It would be impossible to state that some given magnitude is the maximum that will ever occur, and it is therefore impossible to design for the maximum, since it cannot be ascertained. It seems more logical to design for a predicted flood of some selected interval ---a flood magnitude that could reasonably be expected to occur once within a given number of years. For example, a bridge may be designed for a 50-year flood interval; that is, for a flood which is expected (according to the laws of probability) to occur on the average of one time in 50 years. Once this design flood frequency, or interval of expected occurrence, has been decided, the analysis to determine a magnitude is made. Whenever possible, this analysis is based upon gauged stream records. In areas and for streams where flood frequency and magnitude records are not available, an analysis can still be made. With data from gauged streams in the vicinity, regional flood frequencies can be worked out; with a correlation between the computed discharge for the ungauged stream and the regional flood frequency, a flood frequency curve can be computed for the stream in question. Highway CulvertsAny closed conduit used to conduct surface runoff from one side of a roadway to the other is referred to as a culvert. Culverts vary in size from large multiple installations used in lieu of a bridge to small circular or elliptical pipe, and their design varies in significance. Accepted practice treats conduits under the roadway as culverts. Although the unit cost of culverts is much less than that of bridges, they are far more numerous, normally averaging about eight to the mile, and represent a greater cost in highway. Statistics show that about 15 cents of the highway construction dollar goes to culverts, as compared with 10 cents for bridge. Culvert design then is equally as important as that of bridges or other phases of highway and should be treated accordingly.Municipal Storm DrainageIn urban and suburban areas, runoff waters are handled through a system of drainage structures referred to as storm sewers and their appurtenances. The drainage problem is increased in these areas primarily for two reasons: the impervious nature of the area creates a very high runoff; and there is little room for natural water courses. It is often necessary to collect the entire storm water into a system of pipes and transmit it over considerable distances before it can be loosed again as surface runoff. This collection and transmission further increase the problem, since all of the water must be collected with virtually no ponding, thus eliminating any natural storage; and though increased velocity the peak runoffs are reached more quickly. Also, the shorter times of peaks cause the system to be more sensitive to short-duration, high-intensity rainfall. Storm sewers, like culverts and bridges, are designed for storms of various intensity –return-period relationship, depending upon the economy and amount of ponding that can be tolerated.Airport DrainageThe problem of providing proper drainage facilities for airports is similar in many ways to that of highways and streets. However, because of the large and relatively flat surface involved the varying soil conditions, the absence of natural water courses and possible side ditches, and the greater concentration of discharge at the terminus of the construction area, some phases of the problem are more complex. For the average airport the overall area to be drained is relatively large and an extensive drainage system is required. The magnitude of such a system makes it even more imperative that sound engineeringprinciples based on all of the best available data be used to ensure the most economical design. Overdesign of facilities results in excessive money investment with no return, and underdesign can result in conditions hazardous to the air traffic using the airport.In other to ensure surfaces that are smooth, firm, stable, and reasonably free from flooding, it is necessary to provide a system which will do several things. It must collect and remove the surface water from the airport surface; intercept and remove surface water flowing toward the airport from adjacent areas; collect and remove any excessive subsurface water beneath the surface of the airport facilities and in many cases lower the ground-water table; and provide protection against erosion of the sloping areas. Ditches and Cut-slope DrainageA highway cross section normally includes one and often two ditches paralleling the roadway. Generally referred to as side ditches these serve to intercept the drainage from slopes and to conduct it to where it can be carried under the roadway or away from the highway section, depending upon the natural drainage. To a limited extent they also serve to conduct subsurface drainage from beneath the roadway to points where it can be carried away from the highway section.A second type of ditch, generally referred to as a crown ditch, is often used for the erosion protection of cut slopes. This ditch along the top of the cut slope serves to intercept surface runoff from the slopes above and conduct it to natural water courses on milder slopes, thus preventing the erosion that would be caused by permitting the runoff to spill down the cut faces.12 Construction techniquesThe decision of how a bridge should be built depends mainly on local conditions. These include cost of materials, available equipment, allowable construction time and environmental restriction. Since all these vary with location and time, the best construction technique for a given structure may also vary. Incremental launching or Push-out MethodIn this form of construction the deck is pushed across the span with hydraulic rams or winches. Decks of prestressed post-tensioned precast segments, steel or girders have been erected. Usually spans are limited to 50～60 m to avoid excessive deflection and cantilever stresses , although greater distances have been bridged by installing temporary support towers . Typically the method is most appropriate for long, multi-span bridges in the range 300 ~ 600 m ,but ,much shorter and longer bridges have been constructed . Unfortunately, this very economical mode of construction can only be applied when both the horizontal and vertical alignments of the deck are perfectly straight, or alternatively of constant radius. Where pushing involves a small downward grade (4% ~ 5%) then a braking system should be installed to prevent the deck slipping away uncontrolled and heavy bracing is then needed at the restraining piers.Bridge launching demands very careful surveying and setting out with continuous and precise checks made of deck deflections. A light aluminum or steel-launching nose forms the head of the deck to provide guidance over the pier. Special teflon or chrome-nickel steel plate bearings are used to reduce sliding friction to about 5% of the weight, thus slender piers would normally be supplemented with braced columns to avoid cracking and other damage. These columns would generally also support the temporary friction bearings and help steer the nose.In the case of precast construction, ideally segments should be cast on beds near the abutments and transferred by rail to the post-tensioning bed, the actual transport distance obviously being kept to the minimum. Usually a segment is cast against the face of the previously concerted unit to ensure a good fit when finally glued in place with an epoxy resin. If this procedure is not adopted , gaps of approximately 500mm shold be left between segments with the reinforcements running through andstressed together to form a complete unit , but when access or space on the embankment is at a premium it may be necessary to launch the deck intermittently to allow sections to be added progressively .The correponding prestressing arrangements , both for the temporary and permanent conditions would be more complicated and careful calculations needed at all positions .The pricipal advantage of the bridge-launching technique is the saving in falsework, especially for high decks. Segments can also be fabricated or precast in a protected environment using highly productive equipment. For concrete segment, typically two segment are laid each week (usually 10 ~ 30 m in length and perhaps 300 to 400 tonnes in weight) and after posttensioning incrementally launched at about 20 m per day depending upon the winching/jacking equipment.Balanced Cantiulever ConstructionDevelopment in box section and prestressed concrete led to short segment being assembled or cast in place on falsework to form a beam of full roadway width. Subsequently the method was refined virtually to eliminate the falsework by using a previously constructed section of the beam to provide the fixing for a subsequently cantilevered section. The principle is demonsrated step-by-step in the example shown in Fig.1.In the simple case illustrated, the bridge consists of three spans in the ratio 1:1:2. First the abutments and piers are constructed independently from the bridge superstructure. The segment immediately above each pier is then either cast in situ or placed as a precast unit .The deck is subsequently formed by adding sections symmetrically either side.Ideally sections either side should be placed simultaneously but this is usually impracticable and some inbalance will result from the extra segment weight, wind forces, construction plant and material. When the cantilever has reached both the abutment and centre span,work can begin from the other pier , and the remainder of the deck completed in a similar manner . Finally the two individual cantilevers are linked at the centre by a key segment to form a single span. The key is normally cast in situ.The procedure initially requires the first sections above the column and perhaps one or two each side to be erected conventionally either in situ concrete or precast and temporarily supported while steel tendons are threaded and post-tensioned . Subsequent pairs of section are added and held in place by post-tensioning followed by grouting of the ducts. During this phase only the cantilever tendons in the upper flange and webs are tensioned. Continuity tendons are stressed after the key section has been cast in place. The final gap left between the two half spans should be wide enough to enable the jacking equipment to be inserted. When the individual cantilevers are completed and the key section inserted the continuity tendons are anchored symmetrically about the centre of the span and serve to resist superimposed loads, live loads, redistribution of dead loads and cantilever prestressing forces.The earlier bridges were designed on the free cantilever principle with an expansion joint incorporated at the center .Unfortunately，settlements , deformations , concrete creep and prestress relaxation tended to produce deflection in each half span , disfiguring the general appearance of the bridge and causing discomfort to drivers .These effects coupled with the difficulties in designing a suitable joint led designers to choose a continuous connection, resulting in a more uniform distribution of the loads and reduced deflection. The natural movements were provided for at the bridge abutments using sliding bearings or in the case of long multi-span bridges, joints at about 500 m centres.Special Requirements in Advanced Construction TechniquesThere are three important areas that the engineering and construction team has to consider:(1) Stress analysis during construction: Because the loadings and support conditions of the bridge are different from the finished bridge, stresses in each construction stage must be calculated to ensurethe safety of the structure .For this purpose, realistic construction loads must be used and site personnel must be informed on all the loading limitations. Wind and temperature are usually significant for construction stage.(2) Camber: In order to obtain a bridge with the right elevation, the required camber of the bridge at each construction stage must be calculated. It is required that due consideration be given to creep and shrinkage of the concrete. This kind of the concrete. This kind of calculation, although cumbersome, has been simplified by the use of the compiters.(3) Quality control: This is important for any method construction, but it is more so for the complicated construction techniques. Curing of concrete, post-tensioning, joint preparation, etc. are detrimental to a successful structure. The site personnel must be made aware of the minimum concrete strengths required for post-tensioning, form removal, falsework removal, launching and other steps of operations.Generally speaking, these advanced construction techniques require more engineering work than the conventional falsework type construction, but the saving could be significant.大桥涵洞在大多数情况中桥梁的高度和跨度完全取决于河流的流量，桥梁的高度和跨度必须能够容纳最大洪水量.事实上，这不仅仅是洪水最大流量的问题,还需要在不同时间间隔预测不同程度的水灾。

电气毕业设计用外文翻译(中英文对照)

The Transformer on load ﹠Introduction to DC Machine sThe Transformer on loadIt has been shown that a primary input voltage 1V can be transformed to any desired open-circuit secondary voltage 2E by a suitable choice of turns ratio. 2E is available for circulating a load current impedance. For the moment, a lagging power factor will be considered. The secondary current and the resulting ampere-turns 22N I will change the flux, tending to demagnetize the core, reduce m Φ and with it 1E . Because the primary leakage impedance drop is so low, a small alteration to 1E will cause an appreciable increase of primary current from 0I to a new value of 1I equal to ()()i jX R E V ++111/. The extra primary current and ampere-turns nearly cancel the whole of the secondary ampere-turns. This being so , the mutual flux suffers only a slight modification and requires practically the same net ampere-turns 10N I as on no load. The total primary ampere-turns are increased by an amount 22N I necessary to neutralize the same amount of secondary ampere-turns. In the vector equation , 102211N I N I N I =+; alternatively, 221011N I N I N I -=. At full load, the current 0I is only about 5% of the full-load current and so 1I is nearly equal to 122/N N I . Because in mind that 2121/N N E E =, the input kV A which is approximately 11I E is also approximately equal to the output kV A, 22I E .The physical current has increased, and with in the primary leakage flux to which it is proportional. The total flux linking the primary ,111Φ=Φ+Φ=Φm p , is shown unchanged because the total back e.m.f.,（dt d N E /111Φ-）is still equal and opposite to 1V . However, there has been a redistribution of flux and the mutual component has fallen due to the increase of 1Φ with 1I . Although the change is small, the secondary demand could not be met without a mutual flux and e.m.f. alteration to permit primary current to change. The net flux s Φlinking the secondary winding has been further reduced by the establishment of secondary leakage flux due to 2I , and this opposes m Φ. Although m Φ and2Φ are indicated separately , they combine to one resultant in the core which will be downwards at the instant shown. Thus the secondary terminal voltage is reduced to dt d N V S /22Φ-= which can be considered in two components, i.e. dt d N dt d N V m //2222Φ-Φ-=or vectorially 2222I jX E V -=. As for the primary, 2Φ is responsible for a substantially constant secondaryleakage inductance 222222/Λ=ΦN i N . It will be noticed that the primary leakage flux is responsiblefor part of the change in the secondary terminal voltage due to its effects on the mutual flux. The two leakage fluxes are closely related; 2Φ, for example, by its demagnetizing action on m Φ has caused the changes on the primary side which led to the establishment of primary leakage flux.If a low enough leading power factor is considered, the total secondary flux and the mutual flux are increased causing the secondary terminal voltage to rise with load. p Φ is unchanged in magnitude from the no load condition since, neglecting resistance, it still has to provide a total back e.m.f. equal to 1V . It is virtually the same as 11Φ, though now produced by the combined effect of primary and secondary ampere-turns. The mutual flux must still change with load to give a change of 1E and permit more primary current to flow. 1E has increased this time but due to the vector combination with 1V there is still an increase of primary current.Two more points should be made about the figures. Firstly, a unity turns ratio has been assumed for convenience so that '21E E =. Secondly, the physical picture is drawn for a different instant of time from the vector diagrams which show 0=Φm , if the horizontal axis is taken as usual, to be the zero time reference. There are instants in the cycle when primary leakage flux is zero, when the secondary leakage flux is zero, and when primary and secondary leakage flux is zero, and when primary and secondary leakage fluxes are in the same sense.The equivalent circuit already derived for the transformer with the secondary terminals open, can easily be extended to cover the loaded secondary by the addition of the secondary resistance and leakage reactance.Practically all transformers have a turns ratio different from unity although such an arrangement issometimes employed for the purposes of electrically isolating one circuit from another operating at the same voltage. To explain the case where 21N N ≠ the reaction of the secondary will be viewed from the primary winding. The reaction is experienced only in terms of the magnetizing force due to the secondary ampere-turns. There is no way of detecting from the primary side whether 2I is large and 2N small or vice versa, it is the product of current and turns which causes the reaction. Consequently, a secondary winding can be replaced by any number of different equivalent windings and load circuits which will give rise to an identical reaction on the primary .It is clearly convenient to change the secondary winding to an equivalent winding having the same number of turns 1N as the primary.With 2N changes to 1N , since the e.m.f.s are proportional to turns, 2212)/('E N N E = which is the same as 1E .For current, since the reaction ampere turns must be unchanged 1222'''N I N I = must be equal to 22N I .i.e. 2122)/(I N N I =.For impedance , since any secondary voltage V becomes V N N )/(21, and secondary current I becomes I N N )/(12, then any secondary impedance, including load impedance, must become I V N N I V /)/('/'221=. Consequently, 22212)/('R N N R = and 22212)/('X N N X = .If the primary turns are taken as reference turns, the process is called referring to the primary side. There are a few checks which can be made to see if the procedure outlined is valid.For example, the copper loss in the referred secondary winding must be the same as in the original secondary otherwise the primary would have to supply a different loss power. ''222R I must be equal to 222R I . ）222122122/()/(N N R N N I ∙∙ does in fact reduce to 222R I .Similarly the stored magnetic energy in the leakage field )2/1(2LI which is proportional to 22'X I will be found to check as ''22X I . The referred secondary 2212221222)/()/(''I E N N I N N E I E kVA =∙==.The argument is sound, though at first it may have seemed suspect. In fact, if the actual secondarywinding was removed physically from the core and replaced by the equivalent winding and load circuit designed to give the parameters 1N ,'2R ,'2X and '2I , measurements from the primary terminals would be unable to detect any difference in secondary ampere-turns, kVA demand or copper loss, under normal power frequency operation.There is no point in choosing any basis other than equal turns on primary and referred secondary, but it is sometimes convenient to refer the primary to the secondary winding. In this case, if all the subscript 1’s are interchanged for the subscript 2’s, the necessary referring constants are easily found; e.g. 2'1R R ≈,21'X X ≈; similarly 1'2R R ≈ and 12'X X ≈.The equivalent circuit for the general case where 21N N ≠ except that m r has been added to allow for iron loss and an ideal lossless transformation has been included before the secondary terminals to return '2V to 2V .All calculations of internal voltage and power losses are made before this ideal transformation is applied. The behaviour of a transformer as detected at both sets of terminals is the same as the behaviour detected at the corresponding terminals of this circuit when the appropriate parameters are inserted. The slightly different representation showing the coils 1N and 2N side by side with a core in between is only used for convenience. On the transformer itself, the coils are , of course , wound round the same core.Very little error is introduced if the magnetising branch is transferred to the primary terminals, but a few anomalies will arise. For example ,the current shown flowing through the primary impedance is no longer the whole of the primary current. The error is quite small since 0I is usually such a small fraction of 1I . Slightly different answers may be obtained to a particular problem depending on whether or not allowance is made for this error. With this simplified circuit, the primary and referred secondary impedances can be added to give: 221211)/(Re N N R R += and 221211)/(N N X X Xe +=It should be pointed out that the equivalent circuit as derived here is only valid for normal operation at power frequencies; capacitance effects must be taken into account whenever the rate of change of voltage would give rise to appreciable capacitance currents, dt CdV I c /=. They are important at high voltages and at frequencies much beyond 100 cycles/sec. A further point is not theonly possible equivalent circuit even for power frequencies .An alternative , treating the transformer as a three-or four-terminal network, gives rise to a representation which is just as accurate and has some advantages for the circuit engineer who treats all devices as circuit elements with certain transfer properties. The circuit on this basis would have a turns ratio having a phase shift as well as a magnitude change, and the impedances would not be the same as those of the windings. The circuit would not explain the phenomena within the device like the effects of saturation, so for an understanding of internal behaviour .There are two ways of looking at the equivalent circuit:(a) viewed from the primary as a sink but the referred load impedance connected across '2V ,or (b) viewed from the secondary as a source of constant voltage 1V with internal drops due to 1Re and 1Xe . The magnetizing branch is sometimes omitted in this representation and so the circuit reduces to a generator producing a constant voltage 1E (actually equal to 1V ) and having an internal impedance jX R + (actually equal to 11Re jXe +).In either case, the parameters could be referred to the secondary winding and this may save calculation time .The resistances and reactances can be obtained from two simple light load tests.Introduction to DC MachinesDC machines are characterized by their versatility. By means of various combination of shunt, series, and separately excited field windings they can be designed to display a wide variety of volt-ampere or speed-torque characteristics for both dynamic and steadystate operation. Because of the ease with which they can be controlled , systems of DC machines are often used in applications requiring a wide range of motor speeds or precise control of motor output.The essential features of a DC machine are shown schematically. The stator has salient poles and is excited by one or more field coils. The air-gap flux distribution created by the field winding is symmetrical about the centerline of the field poles. This axis is called the field axis or direct axis.As we know , the AC voltage generated in each rotating armature coil is converted to DC in the external armature terminals by means of a rotating commutator and stationary brushes to which the armature leads are connected. The commutator-brush combination forms a mechanical rectifier,resulting in a DC armature voltage as well as an armature m.m.f. wave which is fixed in space. The brushes are located so that commutation occurs when the coil sides are in the neutral zone , midway between the field poles. The axis of the armature m.m.f. wave then in 90 electrical degrees from the axis of the field poles, i.e., in the quadrature axis. In the schematic representation the brushes are shown in quarature axis because this is the position of the coils to which they are connected. The armature m.m.f. wave then is along the brush axis as shown.. (The geometrical position of the brushes in an actual machine is approximately 90 electrical degrees from their position in the schematic diagram because of the shape of the end connections to the commutator.)The magnetic torque and the speed voltage appearing at the brushes are independent of the spatial waveform of the flux distribution; for convenience we shall continue to assume a sinusoidal flux-density wave in the air gap. The torque can then be found from the magnetic field viewpoint.The torque can be expressed in terms of the interaction of the direct-axis air-gap flux per pole d Φ and the space-fundamental component 1a F of the armature m.m.f. wave . With the brushes in the quadrature axis, the angle between these fields is 90 electrical degrees, and its sine equals unity. For a P pole machine 12)2(2a d F P T ϕπ= In which the minus sign has been dropped because the positive direction of the torque can be determined from physical reasoning. The space fundamental 1a F of the sawtooth armature m.m.f. wave is 8/2π times its peak. Substitution in above equation then gives a d a a d a i K i mPC T ϕϕπ==2 Where a i =current in external armature circuit;a C =total number of conductors in armature winding;m =number of parallel paths through winding;And mPC K a a π2=Is a constant fixed by the design of the winding.The rectified voltage generated in the armature has already been discussed before for an elementary single-coil armature. The effect of distributing the winding in several slots is shown in figure ,in which each of the rectified sine waves is the voltage generated in one of the coils, commutation taking place at the moment when the coil sides are in the neutral zone. The generated voltage as observed from the brushes is the sum of the rectified voltages of all the coils in series between brushes and is shown by the rippling line labeled a e in figure. With a dozen or so commutator segments per pole, the ripple becomes very small and the average generated voltage observed from the brushes equals the sum of the average values of the rectified coil voltages. The rectified voltage a e between brushes, known also as the speed voltage, is m d a m d a a W K W mPC e ϕϕπ==2 Where a K is the design constant. The rectified voltage of a distributed winding has the same average value as that of a concentrated coil. The difference is that the ripple is greatly reduced.From the above equations, with all variable expressed in SI units:m a a Tw i e =This equation simply says that the instantaneous electric power associated with the speed voltage equals the instantaneous mechanical power associated with the magnetic torque , the direction of power flow being determined by whether the machine is acting as a motor or generator.The direct-axis air-gap flux is produced by the combined m.m.f. f f i N ∑ of the field windings, the flux-m.m.f. characteristic being the magnetization curve for the particular iron geometry of the machine. In the magnetization curve, it is assumed that the armature m.m.f. wave is perpendicular to the field axis. It will be necessary to reexamine this assumption later in this chapter, where the effects of saturation are investigated more thoroughly. Because the armature e.m.f. is proportional to flux timesspeed, it is usually more convenient to express the magnetization curve in terms of the armature e.m.f. 0a e at a constant speed 0m w . The voltage a e for a given flux at any other speed m w is proportional to the speed,i.e. 00a m m a e w w e Figure shows the magnetization curve with only one field winding excited. This curve can easily be obtained by test methods, no knowledge of any design details being required.Over a fairly wide range of excitation the reluctance of the iron is negligible compared with that of the air gap. In this region the flux is linearly proportional to the total m.m.f. of the field windings, the constant of proportionality being the direct-axis air-gap permeance.The outstanding advantages of DC machines arise from the wide variety of operating characteristics which can be obtained by selection of the method of excitation of the field windings. The field windings may be separately excited from an external DC source, or they may be self-excited; i.e., the machine may supply its own excitation. The method of excitation profoundly influences not only the steady-state characteristics, but also the dynamic behavior of the machine in control systems.The connection diagram of a separately excited generator is given. The required field current is a very small fraction of the rated armature current. A small amount of power in the field circuit may control a relatively large amount of power in the armature circuit; i.e., the generator is a power amplifier. Separately excited generators are often used in feedback control systems when control of the armature voltage over a wide range is required. The field windings of self-excited generators may be supplied in three different ways. The field may be connected in series with the armature, resulting in a shunt generator, or the field may be in two sections, one of which is connected in series and the other in shunt with the armature, resulting in a compound generator. With self-excited generators residual magnetism must be present in the machine iron to get the self-excitation process started.In the typical steady-state volt-ampere characteristics, constant-speed primemovers being assumed. The relation between the steady-state generated e.m.f. a E and the terminal voltage t V isa a a t R I E V -=Where a I is the armature current output and a R is the armature circuit resistance. In a generator, a E is large than t V ; and the electromagnetic torque T is a countertorque opposing rotation.The terminal voltage of a separately excited generator decreases slightly with increase in the load current, principally because of the voltage drop in the armature resistance. The field current of a series generator is the same as the load current, so that the air-gap flux and hence the voltage vary widely with load. As a consequence, series generators are not often used. The voltage of shunt generators drops off somewhat with load. Compound generators are normally connected so that the m.m.f. of the series winding aids that of the shunt winding. The advantage is that through the action of the series winding the flux per pole can increase with load, resulting in a voltage output which is nearly constant. Usually, shunt winding contains many turns of comparatively heavy conductor because it must carry the full armature current of the machine. The voltage of both shunt and compound generators can be controlled over reasonable limits by means of rheostats in the shunt field. Any of the methods of excitation used for generators can also be used for motors. In the typical steady-state speed-torque characteristics, it is assumed that the motor terminals are supplied from a constant-voltage source. In a motor the relation between the e.m.f. a E generated in the armature and the terminal voltage t V isa a a t R I E V +=Where a I is now the armature current input. The generated e.m.f. a E is now smaller than the terminal voltage t V , the armature current is in the opposite direction to that in a motor, and the electromagnetic torque is in the direction to sustain rotation ofthe armature.In shunt and separately excited motors the field flux is nearly constant. Consequently, increased torque must be accompanied by a very nearly proportional increase in armature current and hence by a small decrease in counter e.m.f. to allow this increased current through the small armature resistance. Since counter e.m.f. is determined by flux and speed, the speed must drop slightly. Like the squirrel-cage induction motor ,the shunt motor is substantially a constant-speed motor having about 5 percent drop in speed from no load to full load. Starting torque and maximum torque are limited by the armature current that can be commutated successfully.An outstanding advantage of the shunt motor is ease of speed control. With a rheostat in the shunt-field circuit, the field current and flux per pole can be varied at will, and variation of flux causes the inverse variation of speed to maintain counter e.m.f. approximately equal to the impressed terminal voltage. A maximum speed range of about 4 or 5 to 1 can be obtained by this method, the limitation again being commutating conditions. By variation of the impressed armature voltage, very wide speed ranges can be obtained.In the series motor, increase in load is accompanied by increase in the armature current and m.m.f. and the stator field flux (provided the iron is not completely saturated). Because flux increases with load, speed must drop in order to maintain the balance between impressed voltage and counter e.m.f.; moreover, the increase in armature current caused by increased torque is smaller than in the shunt motor because of the increased flux. The series motor is therefore a varying-speed motor with a markedly drooping speed-load characteristic. For applications requiring heavy torque overloads, this characteristic is particularly advantageous because the corresponding power overloads are held to more reasonable values by the associated speed drops. Very favorable starting characteristics also result from the increase in flux with increased armature current.In the compound motor the series field may be connected either cumulatively, so that its.m.m.f.adds to that of the shunt field, or differentially, so that it opposes. The differential connection is very rarely used. A cumulatively compounded motor hasspeed-load characteristic intermediate between those of a shunt and a series motor, the drop of speed with load depending on the relative number of ampere-turns in the shunt and series fields. It does not have the disadvantage of very high light-load speed associated with a series motor, but it retains to a considerable degree the advantages of series excitation.The application advantages of DC machines lie in the variety of performance characteristics offered by the possibilities of shunt, series, and compound excitation. Some of these characteristics have been touched upon briefly in this article. Still greater possibilities exist if additional sets of brushes are added so that other voltages can be obtained from the commutator. Thus the versatility of DC machine systems and their adaptability to control, both manual and automatic, are their outstanding features.负载运行的变压器及直流电机导论负载运行的变压器通过选择合适的匝数比，一次侧输入电压1V 可任意转换成所希望的二次侧开路电压2E 。

绿色建筑毕业设计外文翻译中英文对照(可编辑)

绿色建筑毕业设计外文翻译中英文对照（可编辑）########## 大学本科毕业设计外文资料译文年级: 2008级学号: 20087221姓名: 朱莉专业: 铁道工程指导老师:2012年6月原文:Green BuildingAbstract: Green building refers to doing its best to imizeconservation of resources energy, land, water, and wood,protecting the environment and reducing pollution in its life cycle. Providing people with healthy, appropriate and efficient use of space, and nature in harmony symbiosis buildings. I described more details of green building design’ notion, green building’ de sign, as well as the significance of the concept of green building and improving the effectivenessanalysis of the external effects of green building measures, Key words: green buildings; protect the ecology; signification ; analysing the effectsWhat is a green buildingGreen building refers to building life cycle,the imum conservation of resources energy, land, water and materials, protecting the environment and reducing pollution, providing people with healthy, appropriate and efficient use of space, and nature harmony of the buildingThe so-called green building "green" does not mean a general sense of three-dimensional green, roof garden, but represents a concept or symbol, refers to building environmentally and friendly, makes full use of natural resources, environment and basic ecological damage to the environment without balance of a building under construction, but also known as sustainable building, eco-building, back into the wild construction, energy saving construction Green building interior layout is very reasonable, to minimize the use of synthetic materials, full use of the sun, saves energy for the residents and creates almost-natural feeling People, architectures and the natural environment for the harmonious development goals, in the use of natural and artificial means to create good conditions and healthy living environment, as much as possible to control and reduce the use and destruction of the natural environment, to fully reflect the nature obtain and return balance2. the meaning of green buildingThe basic connotation of green building can be summarized as: to reduce the load on the environment architecture, which saves energy and resources; provides a safe, healthy, comfortable living space with goods; affinity with the natural environment, so that people and building's coexistence with the environment and sustainable development becomes harmonious3.Development of the significance of green building rating systemEstablish green building rating system is a revolution in the fieldof architecture and the Enlightenment, its far more than energy savings. It is innovative in many ways and organic synthesis, thereby building in harmony with nature, full utilization of resources and energy, create healthy, comfortable and beautiful living space. It's revolutionary for the field of architecture from the technical, social and economicangles3.1 Technical SignificanceGreen building study of early technical problems of individual-based, technology is isolated and one-sided, not formed an organic whole, the integration of design and economic study of consciousness is far fromthe only strategy of economic analysis phase of the subsidiary's knowledgeHowever, individual technical research results of early modern green building techniques for the multi-dimensional development and systems integration will lay a solid foundation. Since the nineties of the 20th century, with the understanding of green building gradually deepen and mature, people give up way too utopian thinking environmental consciousness and moral constraints and spontaneous green behavior, turned to explore more workable environmental philosophy, environmental and capital combined into the future world with the new direction of development of environmental protection, green building has entereda result of ecological ethics from the practice of promoting ecological research to deepen the new stage. Green Building Technology takes on the natural science, social science, humanities, computer science,information science and other subjects the trend of integration of research results, making green building design into the multi-dimensional stage of development strategy study. The deepening of green building technology strategy and development in materials, equipment, morphology and so on. Various advanced fields, in technology development, technology and other design elements of the integration is also starting from the past the simple addition, more attention to the periphery ofthe retaining structure itself design technology and architecture to combine the overall system change, gradually becoming green building systems. Green building rating system was established green building technologies gradually improve and systematize the inevitable result, it is the organic integration of green building technology, a platformbuilt to green building technology, information technology, computer technology and many other subjects can be a unified platform in their respective roles, the establishment of a comprehensive evaluation system for designers, planners, engineers and managers a more simple, Guizhangmingque green building assessment tools and design guidelines with clear rule3.2 The social significanceGreen building rating system reflects the socialsignificance of the main advocates of the new way of life,heightened awareness and public participation in the continuation oflocal culture are two aspects To promote a healthy lifestyle. Green building rating system, the social significance of the primary advocatea healthy lifestyle, which is based on the design and construction ofgreen buildings as a community education process. The principles of green building rating system is the effective use of resources and ecological rules to follow, based on the health of building space to create and maintain sustainable development. The concept of the past to correct people's misconceptions about consumer lifestyles, that can not blindly pursue material luxury, but should keep the environment under the premise of sustainable use of modest comfort to pursue life. From the fundamental terms, construction is to meet human needs built up of material goods as people's lifestyle is not sustainable when, the value of green building itself will be reduced, but only had a real social need When the requirements of sustainable development and way of life that matches the green building to achieve the best results Enhanced awareness of public participation. Green Building Rating system is not a monopoly for the design staff of professional tools, but for planners, designers, engineers, managers, developers, property owners, jointly owned by the public and other assessment tools. It brokes the previous professional development of the monopoly to encourage the participation of the publicand other public officers. Through public participation, the introduction of architects and other building users, the construction of dialogue participants, making the original design process dominated by the architect becomes more open. Proved the involvement of various views and a good help to create a dynamic culture, embody social justice community3.3 The economic significanceGreen building rating system, theeconomic significance can be divided into macro and micro levels. At the macro level, the green building rating system from the system life-cycle perspective, the green building design integrated into the economic issues involved in the production from the building materials, design, construction, operation, resource use, waste disposal, recycling of demolition until the natural resources the whole process. Economic considerations of green building is no longer limited to the design process itself, while the policy extended to the design of the narrow role to play to support the policy level, including the establishment of "green labeling" system, improving the construction environmental audit and management system, increase and construction-related energy consumption, pollutant emissions and other acts of tax efforts, improve the legal system of environmental protection, from the increase in government construction projects on the sustainability of economic support and raise the cost to the construction of polluting the environment acts as the costs for green buildings design and construction to create a favorable externalenvironment. This goal is not entirely the responsibility of government agencies, as the architects involved in design work as a sound system of responsibility for recommendations obligations, because only the most from the practice of the need is real and urgent. The related policy issues in green building design strategies, building a system to solve the economic problems facing the important aspects. At the micro level, the current from the economic point of Design Strategyis more fully consider the economic operation of the project, and specific technical strategies accordingly adjusted3.4 Ethical SignificanceGreen building rating system, the theoretical basis of the concept of sustainable development, therefore, whether the evaluation system of each country how much difference in structure, they all have one thing in common: To reduce the burden of ecological environment, improve construction quality of the environment for future generations to remain the development of room. This radically changes the long-sought human blindly to the natural attitude, reflecting people's understanding of the relationship between man and nature by the opposition to the uniform change. According to the current global energy reserves and resources distribution, the Earth's natural environment is also far from the edge of exhaustion, enough people enjoy the luxury of contemporary material life. But now we have to consume a resource, it means that future generations will be less of a living space. More importantly, if we consume the natural environment more than it can limit self-renewal, then the future of the younger generation is facing the planet's ecosystems can not recover the risk into a real crisis. Therefore we can say, the development of green buildings and their corresponding evaluation system, for more contemporary people is the responsibility and obligations. For more the interests of future generations and advantages for green building design.4.Green building design include the followings:Saving energy: full use of solar energy, using energy-efficient building reducing heating and air conditioning use. Set according to the principle of natural ventilation cooling system that allows efficient use of building to the dominant wind direction in summer. Adapted to local climatic conditions, building use form and general layout of the plane Resource conservation: in the building design, construction and selection of construction materials, are considered fair use and disposal of resources. To reduce the use of resources, strive to make the use of renewable resources. Conserve water resources, including water conservation and greeningReturn to Nature: Green Building exterior to emphasize integration with the surrounding environment, harmony, movement each other so that the protection of natural ecological environment5 .Effects of green building5.1 Effects of the composition of green buildingEffects of green building, including internal effects and external effects, direct benefits and direct costs as the internal effect, known as the indirect benefits and indirect costs of external effects, according to engineering economics point of view: the internal effects can be financial evaluation, external effects should be economic evaluation, economic evaluation is based on the so-called rational allocation of scarce resources and socio-economic principles of sustainable development, from the perspective of the overall national economy, study projects spending of social resources and contributions to the community to evaluate the project's economic and reasonable andexternal effects generally include industry effects, environmental and ecological effects, technology diffusion effect, the external effectwill cause the private costs internal costs or indirect costs and social costs inconsistent, leading to the actual price is different from the best price. From the perspective of sustainable development, green building assessment effects of the main indicators of external effectsSince beginning the development of green building, unity of quantitative indicators system is still not established, I believe that the following aspects should be analyzed: 1 strictly control the construction industry, size, limit the number of employees. Extensive growth model epitomized by the struggle over the construction project, the construction process using human wave tactics, once the state limit the scale of construction, will form the "adequate", which will not reduce the degree of mechanization, labor, thelow level. 2 more investments in upgrade technology, establish and perfect the mechanism for scientific and technical equipment. Focus on the development and application of building technology, combined with the project, the characteristics of future construction, a planned way scientific and technological research and development of new machinery, new processes, new materials, and actively introduction, absorb and assimilate the advanced scientific and technological achievements of science and technology to improve the level of mechanization. 3 in urban planning, survey and design through the "green building" ideas. Family housing and urban construction or alteration must remain in the room,from lighting, ventilation, drainage and control the damages to the environment. 4 construction work, reduced resource consumption, the production process in construction, energy saving measures should be adopted to prevent the excessive consumption of land resources, water resources, power resources5.2 External effects of the challenges to building the economyUnder the control of the government's intervention, to a certain extent on the efficient allocation of resources to strengthen the implementation of energy conservation mandatory standards for construction supervision. To further improve the building energy monitoring system, and strengthen the mandatory building energy efficiency standards in order to carry out the implementation of the project as the main content of the whole process of monitoring, particularly for large public buildings to enhance the building energy regulation, reflected in the project cost on the part of internal costs, making the "non-green building" project's internal costs, internal efficiency and reducing the external costs of green building, the external efficiency increasing, so that effective economic resources to the rational flow of green building6. to improve the external effects of green building measuresEnterprise architecture in the new economy to obtain a competitive advantage, improve the external effects only continually tap the ways and means to improve the external efficiency, reduce external costs, the basic ideas and principles: 1 Construction of natural resources in thelife cycle and minimized energy consumption; 2 reducing building life cycle emissions; 3 protecting the ecological natural environment; 4 to form a healthy, comfortable and safe indoor space; 5 the quality of construction, functionality, performance and environmental unitySummary described above, the meaning of green building design and analysisof its effectiveness and improve the external effects of green building measures. But how does the future design of green buildings need a degree in practice we try to figure out, I believe that green building will become the trend of future construction.译文:绿色建筑摘要: 绿色建筑是指在建筑的全寿命周期内,最大限度地节约资源节能、节地、节水、节材、保护环境和减少污染,为人们提供健康、适用和高效的使用空间,与自然和谐共生的建筑。

本科毕业设计方案中英文翻译高层建筑.doc

本科毕业设计方案中英文翻译高层建筑1外文资料翻译High-Rise BuildingsIntroductionIt is difficult to define a high-rise building . One may say that a low-rise building ranges from 1 to 2 stories . A medium-rise building probably ranges between 3 or 4 stories up to 10 or 20 stories or more .Although the basic principles of vertical and horizontal subsystem design remain the same for low- , medium- , or high-rise buildings , when a building gets high the vertical subsystems become a controlling problem for two reasons . Higher vertical loads will require larger columns , walls , and shafts . But , more significantly , the overturning moment and the shear deflections produced by lateral forces are much larger and must be carefully provided for .The vertical subsystems in a high-rise building transmit accumulated gravity load from story to story , thus requiring larger column or wall sections to support such loading . In addition these same vertical subsystems musttransmit lateral loads , such as wind or seismic loads , to the foundations. However , in contrast to vertical load , lateral load effects on buildings are not linear and increase rapidly with increase in height . For example under wind load , the overturning moment at the base of buildings varies approximately as the square of a buildings may vary as the fourth power of buildings height ,other things being equal. Earthquake produces an even more pronounced effect.When the structure for a low-or medium-rise building is designed for dead and live load , it is almost an inherent property that the columns , walls , and stair or elevator shafts can carry most of the horizontal forces . The problem is primarily one of shear resistance . Moderate addition bracing for rigid frames in“short”buildings can easily be provided by filling certain panels ( or even all panels > without increasing the sizes of the columns and girders otherwise required for vertical loads.Unfortunately , this is not is for high-rise buildings because the problem is primarily resistance to moment and deflection rather than shear alone . Special structural arrangements will often have to be made and additionalstructural material is always required for the columns , girders , walls , and slabs in order to made a high-rise buildings sufficiently resistant to much higher lateral deformations .As previously mentioned , the quantity of structural material required per square foot of floor of a high-rise buildings is in excess of that required for low-rise buildings . The vertical components carrying the gravity load , such as walls , columns , and shafts , will need to be strengthened over the full height of the buildings . But quantity of material required for resisting lateral forces is even more significant .With reinforced concrete , the quantity of material also increases as the number of stories increases . But here it should be noted that the increase in the weight of material added for gravity load is much more sizable than steel ,whereas for wind load the increase for lateral force resistance is not that much more since the weight of a concrete buildings helps to resist overturn . On the other hand , the problem of design for earthquake forces . Additional mass in the upper floors will give rise to a greater overall lateral force under the of seismic effects .In the case of either concrete or steel design , there are certain basic principles for providing additional resistance to lateral to lateral forces and deflections in high-rise buildings without too much sacrifire in economy .1.Increase the effective width of the moment-resisting subsystems . This is very useful becauseincreasing the width will cut down the overturnforce directly and will reduce deflection by thethird power of the width increase , other thingsremaining cinstant . However , this does requirethat vertical components of the widened subsystembe suitably connected to actually gain this benefit.2.Design subsystems such that the components are madeto interact in the most efficient manner . Forexample , use truss systems with chords anddiagonals efficiently stressed , place reinforcingfor walls at critical locations , and optimizestiffness ratios for rigid frames .3.Increase the material in the most effectiveresisting components . For example , materialsadded in the lower floors to the flanges of columnsand connecting girders will directly decrease theoverall deflection and increase the moment resistance without contributing mass in the upper floors where the earthquake problem is aggravated .4.Arrange to have the greater part of vertical loadsbe carried directly on the primary moment-resisting components . This will help stabilize the buildings against tensile overturning forces by precompressing the major overturn-resisting components .5.The local shear in each story can be best resistedby strategic placement if solid walls or the use of diagonal members in a vertical subsystem .Resisting these shears solely by vertical members in bending is usually less economical , since achieving sufficient bending resistance in the columns and connecting girders will require more material and construction energythan using walls or diagonal members .6.Sufficient horizontal diaphragm action should beprovided floor . This will help to bring the various resisting elements to work together instead of separately .。

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本科毕业设计（论文）中英文对照翻译院（系部）电气工程与自动化学院专业名称电气工程及其自动化年级班级电气05-5班学生姓名辛玉龙指导老师封海潮2009年6月10日可编程序控制器可编程序控制器或可编程逻辑控制器（PLC），是一个具有编程能力且完成一定控制功能的设备。

PLC是1968年被美国通用汽车公司的一组工程师设想出来。

可编程控制器起初被设计用于基于程序的灵敏性控制和执行逻辑指令。

人们意识到它的主要优点是被用于梯形图编程语言，简化了维修并且减少了其余部分的清查。

而且，PLC提供了更短的安装时间并通过程序实现比硬接线更加快捷的传输。

当前，世界上已有50多个不同的可编程控制器的生产厂家，因为有如此多的PLC在使用，所以涵盖市场上所有类型的设备是不可能的，幸运的是，根本就没有必要去理解每一个可用的PLC。

所有的机器都有许多的相同之处。

1 可编程控制器的组成所有的可编程控制器都有输入输出接口、存储器编程方法、中央处理器、电源。

输入接口为机器提供一个连接，或使过程被控制。

输入接口是模块且是可扩展的，当控制任务增加时，可以通过扩展模块来接收更多的输入。

输入数量的多少是由CPU和存储容量来限制的。

输入接口的功能与输出接口相反，它将信号从CPU输出，且将其转换成被外部设备螺线圈、电机启动器等设备来产生控制动作。

输出接口本质上也是一个模块，所以当需要时，可以加入输出扩展功能。

PLC的编程语言有多种形式，大多数PLC语言都是基本梯形逻辑，它比继电器逻辑更加先进。

流程图程序语言也被用于一些PLC中，流程图是图形语言，它显示出一个过程中的变量相互之间的关系。

编程设备或程序终端允许用户用程序的形式来键入指令，并存入存储器。

程序是由用户编写且存储于PLC的存储器当中，是在特定处理条件下用来产生正确的控制信号的所需动作的表现形式。

这样一个程序包括允许处理数据进入控制器的存储器中、处理阶段和将命令转换为外部动作阶段。

电源，像中央处理单元一样，电源必须能高质、清洁、可靠供电。

PLC 系统的制造厂家采用专门的设计和生产方法对系统进行供电。

虽然其它的系统将电源作为CPU的内部组成部分，便有些设计却允许对CPU进行外部供电。

不管物理结构有何不同，电源的基本功能是相同的：那就是，提供一个持续的低压的直流电给电力系统，然后保证系统线电压的波动在正常范围内。

2 扫描功能为了让PLC执行存储器中的程序，它必须能够识别在变化莫测的存储地址中都发了生了什么变化读取所在输入输出状态、检查应用程序指令和执行程序都涉及到了PLC的扫描功能。

CPU不断地与系统存储相互作用，去解释执行控制机器或过程的应用程序CPU读取程序所需时间的多少都存储在随机存储器的。

执行控制功能更新所有输出就称为扫描时间。

扫描时间对于一个PLC来说是相当重要的因素，例如，如果一个输入信号在一次扫描仪中状态变化了2次，则PLC将不能识别该信号，这种病况就发生在输入信号变化快于扫描时间。

如果扫描一个程序要用7ms的时间，一个输入触点每3ms就开关一次，则CPU就不知触点的状态在改变。

在多数PLC的扫描时间都是以纠错、编译等不用的操作而调整。

每一个指令进入到程序中都需要一定的时间因为指令要被执行。

所需时间的多少取决于指令。

例如，CPU读取输出线圈的时间要比读取定时器累加器的时间要少。

程序员的总长度本身也对扫描时间有影响。

扫描一个完整程序的时间的长在1ms到255ms扫描时间。

当程序终端与CPU相连，扫描时间也就增加了，因为字将花更长的时间将I/O状态传送到显示屏上。

3 PLC 存储器“存储器使用”涉及到存储每一类型指令所需的存储地址的个数。

每一个PLC生产厂家都用略微不同的方法去组织存储于PLC存储器中的信息。

尽管每一个PLC在存储结构上都有相似性。

例如RAM和ROM片。

被存储信息的位地址和CPU读取这一数据的方法都非常地多变。

典型的PLC完整的处理存储被分为三个主要部分：数据表、用户程序和信息存储区。

这些区存储着关于输入输出设备状态的信息。

同时也存储着程序指令和消息，图2示出了典型PLC的标准存储布局。

这三个区中的每一个都有能力处理大量的信息。

存储器本身的划分是依据多二进制数或位，它有处理能力。

在任何I/O系统中都可行的是对输入输出指令编址的方法。

可编程控制器的I/O被分为两类：一类为固定或不可改变的编址方案；别一类是灵活，可改变的。

地址是在CPU中的控制程序到外部的传感器或传动装置的通路。

PLC的设计决定于系统是否具有变址能力，或是严格地按照其编址操作。

I/O系统基本上包括2个部分：I/O支架、I/O模块，对大多数PLC来说一个模块被插入的地址被定为每个连接设备的地址，一个模块通常包括8个输入或输出，尽管16个输入输出也可以利用。

一个I/O插槽或支架，通常可支持8或16个模块。

4 I/O系统I/O系统提供硬接线元件与CPU的接口。

输入接口允许在关的状态信息传送到CPU，同时也允许CPU通过输出接口与操作信号通信，在其控制下去操作设备。

与其他微处理器一样，CPU也有和输入输出接口相连的时间和控制电路。

在每个循环中输入都被定义为信号，检查它们的地址并不断更新。

当这种相互改变发生时，被修改的输出寄存器内容在这些时间电路的控制下传送到输出接口灵活和编址方案允许设计PLC系统并分配一些区或阶段，这种安装方案允许系统设计都建立控制逻辑软件，而需限制在遵循顺序的I/O，导致了随机编址的I/O系统。

灵活I/O编址的缺点是在一个在的PLC系统中，这样的设计会使当诊断和纠正错误非常困难。

I/O地址或者是十进制或是八进制。

十进制方法遵循顺序I/O分配。

诸如，输入1到8是每一个模块，9到16上第二个模块，17到24是每三个等等，八进制系统基于8个数字，0到7，一个8点I/O模块使用8进制系统会用0~7作为每一个模块，10~17是第二个，20~27是第三个。

在灵活编址方案中，I/O通常被物理设定为一系统并列编址，它与I/O 支架上特殊的插槽一起，一些PLC系统使用紫外线擦除存储器保持I/O地址数据。

地址通常都在初始系统配置中建立。

而且是永久的，在不可变系统中，单个插槽和点地址一般取决于I/O支架连接在一起的顺序，在小型PLC机中系统包含一个支架连接在一起的顺序，在小型PLC机中，系统包含一个支架，因此，I/O地址被生产厂家固定。

5 PID 模块比例—积分—微分模块被用来应用在过程控制中，其中，PID算法在涉及3种方式闭环反馈控制中比较常见。

PID模块允许过程控制在CPU之外发生。

这种安排可以让CPU免除复杂的计算，在PID模块中的微处理器处理数据和比较数据去置位，决定合适的输出信号。

大多数PID模块每个模块有4个控制回路。

状态和诊断指示器被提供允许简单的系统维护，一旦它被设定配置一个模块包括配置模拟信号的类型数字信号的类型和其他条件。

6 程序终端可编程控制器给用户提供一个在CPU存储器中的进入和监视程序的方法进入PLC程序有2种基本方法。

它可用程序终端或电脑软件进行在2种情况下，程序终端被连接到由处理上的连接器CPU。

这种连接器为典型25-pin RS-232C系列通信接口，且与大多数的IBM类计算机相兼容。

程序终端是进入程序和PLC监控而大量使用的设备。

终端最受欢迎的一种类型是迷你编程器，也叫手持编程器，这种类型的编程终端是不贵且可携带的，这就意味着使用更小的PLC，这些设备是与手持计算机一般大小，通常有LED或点阵LCD显示。

键盘包括数字键程序指令键和特殊功能键。

近几年，已经形成朝着使用基于个人电脑程序开发系统方向发展的趋势。

手提电脑或笔记本电脑，微型计算机进行PLC编程起来越受欢迎。

个人电脑也允许简化开发和更方便的PLC编程技术。

Programmable ControllerA programmable controller, or programmable logic controller (PLC), is a device which is capable of being programmed to perform a controlling function.The PLC was first conceived by a group of engineers from the Hydromantic division of General Motors in 1968. Programmable controllers were originally designed to provide flexibility in control based on programming and executing logic instructions .Major advantage were realized by adopting the ladder diagram programming language ,simplifying maintenance ,and reducing the cost of spare parts inventories .Also ,PLCs allowed for shorter installation time and faster commissioning through programming rather than wiring.There are presently over 50 different manufacturers of programmable controllers .Because there are so many different PLCs in use ,it is impossible to cover all the different types of equipment on the market .Fortunately ,it really isn’t necessary to understand every some of the common features of programmable controllers .1.Programmable Controller ComponentsAll programmable controllers have input and output interfaces, memory, a method of programming, a central processing unit (CPU), and a power supply.The input interface provides a connection to the machine or process being controlled.The input interface is modular and can be expanded by adding more modules to allow more inputs when the control task increases. The number of possible inputs is usually limited by the CPU and the size of memory. The output interface performs the opposite function of the input interface. It takes signals from the CPU and translates them into forms that are appropriate toproduce control actions by external devices such as solenoids, motor starters, and so on; The output interface is also modular in nature, so that additional output functions can be incorporated when required.PLC programming languages have many forms. Most PLC languages are based on ladder logic, which is an advanced form of relay logic. Flowchart programming language is also-used with some PLCs. A flowchart is a pictorial language that shows the interconnections of variables within a process.A programming device, or programming terminal, allows a user to enter instructions into memory in the form of a program.A program that is written by a user and stored in a PLC’s memory is a representation of the actions required to produce the correct output control signals for a given process condition. Such a program includes sections that allow process data to be brought into the controller memory, sections that represent decision making, and sections that deal with converting a decision into physical output action.Power Supply，As smart as the central processing unit is, it would be nothing without good, clean, reliable power. The manufacturer of the programmable controller system takes special design and manufacturing care with the system power supply. Some designs allow the power supply to be used external to the main CPU chassis, while others make it an integral part of the system chassis. In spite of the physical differences, the primary function remains the same: that is, to provide a consistent level of clean, low voltage direct current (DC) power to the system electronics, and protects the system from normal line voltage fluctuations.2.PLC Scan FunctionIn order for a CPU to execute a program stored in memory, it must be able to “see” what is occurring in the various memory locations. The procedure of reading the status of all inputs and outputs, examining application programinstructions, and executing the control program is referred to as the scan function of a PLC.The CPU is constantly interacting with system memory to interpret and execute the application program that controls the machine or process. The amount of time required for the CPU to read the program stored in RAM memory, execute the control program, and update all outputs is called the scan time.Scan time is a very important factor in a PLC. For example, if an input signal changes states twice during one scan, the PLC will never be able to “see”the signal. This situation occurs if the change in input signal is faster than scan time. If it takes 7 ms for the CPU to scan a program, and an input contact is opening and closing every 3 ms, the CPU does not know that the contact is changing state. Most PLCs have a scan time which can be adjusted for different operations such as troubleshooting, or debugging.Each instruction entered into a program requires a certain amount of time for the instruction to be executed. The amount of time required depends on the instruction. For example, it takes less time for a CPU to read status of an output coil than it does to read the accumulated value of a timer. The overall length of the program itself will also have an effect on scan time.The length of time required to scan an entire program once varies between 1 m and 255 ms, depending on the manufacturer and model number of the machine being used. The amount of RAM memory allocated by a manufacturer will have an effect on total scan time as well. Typically, 2 ms is added for each 1 kilobyte of memory available. When a programming terminal is connected to CPU, scan time also increases because it takes longer to transmit the status of I/O to the CRT screen.3.PLC MemoryThe term memory utilization refers to the number of memory locationsrequired to store each type of instruction.Each PLC manufacturer uses a slightly different method of organizing the information which is stored in the memory of the PLC. Although all PLCs have similarities in their memory structure, such as RAM and ROM chips, the locations where bits of information are stored and the method the CPU uses to read this data can vary quite substantially.The entire processor memory of a typical PLC is divided into three major parts: data table, user program, and message storage area. These sections store information about the status of an input or output device and are also used to store program instructions and messages. Figures 2 show the standard memory layout for a typical PLC. Each of the three sections is capable of handling various amounts of information. The memory itself is divided according to how many binary digits, or bits, it is capable of handling.4.I/O SystemThe I/O system provides an interface between the hard wired components in the field and the CPU. The input interface allows status information regarding processes to be communicated to the CPU and allows the CPU to communicate operating signals through the output interface to the process devices under its control. Like any other microprocessor, the CPU has timing and control lines that connect to input and output interfaces. While this interchange is taking place, the revised output register contents are transferred to the output interface circuits under the control of these timing lines.The I/O system basically consists of two components: the I/O rack and the I/O module. For most PLCs, the location of where a module is inserted defines the address of each connected device. A module usually consists of either 8 inputs or outputs, although module is also available with 16 inputs or outputs. An I/O rack, or chassis, will generally hold either 8 or 16 modules.An important consideration in any I/O system is the method ofaddressing the input and output instructions. Programmable controller I/O is divided into two general classes: those with fixed or nonflexible addressing schemes and those with flexible, adaptable addressing schemes. Addressing is the way that the control program in the CPU relates to a particular real-world sensor or actuator. The design of a PLC determines whether or not the system is capable of being addressed flexibly, or is rigid in its addressing method.Flexible addressing schemes allow PLC systems to be designed and installed in several sections, or stages. This installation scheme allows system designers to create control logic software without being constrained to follow a sequential I/O assignment, resulting in a randomly addressed I/O system. The disadvantage of flexible I/O addressing is that in large PLC systems such a design may make it difficult to diagnose and correct problems when they occur. This is particularly true when proper PLC I/O documentation is not provided.I/O addressing is either in decimal or octal form. The decimal method follows a sequential assignment of I/O points, such as inputs 1 through 8 for the first module, 9 through 16 for the second module, 17 through 24 for the third, and so on. The octal numbering system is based on 8 digits, 0 through 7. An 8-point I/O module using the octal numbering system would have addresses 0 through 7 for the first module, 10 through 17 for the second, and 20 through 27 for the third module.In flexible addressing schemes, I/O is often addressed by physically setting a series of dual inline package switches, associated with a particular slot in the I/O rack. Some PLC systems use EEPROM memory to hold I/O address data. Addressing is generally established during initial system configuration, and is considered to be permanent. In nonflexible system, individual slot and point addresses are normally determined by the sequence in which the I/O racks are connected together. In the case of some small PLCs, the system contains one rack and therefore has I/O addressing fixed by the manufacturer.5. PID ModuleThe proportional-integral-derivative(PID)module is used in process control applications where PID algorithms are used in what is commonly referred to as three-mode closed-loop feedback control .A PID module allows process control to take place outside the CPU. This arrangement prevents the CPU from being burdened with complex calculations. The microprocessor in the PID module processes data and compares the data to set points provided by the CPU and determines the appropriate output signal. Most PID modules have at least four channels or loops of control per module. Status and diagnostic indicators are provided to allow easy maintenance of the system once it is installed. Configuring a PID module includes configuring the types of analog signals, types of digital signals, and other signal conditions.5.Programming TerminalsA programming terminal provides the user with a method of entering and monitoring a program in the CPU’s memory. There are two basic methods of entering a program into a PLC. It can be done with either a dedicated programming terminal, or with a computer using PLC software. In both cases, the programming terminal is connected to the CPU via the connector on the processor. This connector is typically a 25-pin RS-232C serial communications port, which is compatible with most IBM-type computers.A dedicated programming terminal is a device used exclusively for program entry and PLC monitoring.One of the more popular types of dedicated terminals is the hand-held programmer. This type of programming terminal is an inexpensive and portable means of programming small PLCs. These devices are often the size of hand-held calculators and usually have LED or dot matrix LCD displays. The keyboard consists of numeric keys, programming instruction keys, and special function keys.In recent years, a definite trend has been developing toward the use of personal computer-based program development systems. Laptop, or notebook, microcomputers are becoming increasingly popular for programming PLCs. Personal computers allow the development of simpler and more convenient PLC programming techniques.。

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