土木工程学院交通工程专业
中英文翻译
Road Design
专业：交通工程
英文原文
The Basics of a Good Road
We have known how to build good roads for a long time. Archaeologists have found ancient Egyptian roadsthat carried blocks to the pyramids in 4600 BCE. Later,the Romans built an extensive road system, using the same principles we use today. Some of these roads are
still in service.
If you follow the basic concepts of road building, you will create a road that will last. The ten commandments of a good road are:
（1）Get water away from the road
（2）Build on a firm foundation
（3）Use the best materials
（4）Compact all layers properly
（5）Design for traffic loads and volumes
（6）Design for maintenance
（7）Pave only when ready
（8）Build from the bottom up
（9）Protect your investment
（10）Keep good records
1．Get water away from the road
We can’t overemphasize the importance of good drainage.Engineers estimate that at least 90% of a road’s problems can be related to excess water or to poor waterdrainage. Too much water in any laye r of a road’sstructure can weaken that layer, leading to failure.
In the surface layer, water can cause cracks and potholes. In lower layers it undermines support, causing cracks and potholes. A common sign of water in an asphalt road surface is alligator cracking — an interconnected pattern of cracks forming small irregular shaped pieces that look like alligator skin. Edge cracking, frost heaves, and spring breakup of pavements also point to moisture problems.
To prevent these problems remember that water:
? flows downhill
? needs to flow someplace
? is a problem if it is not flowing
Effective drainage systems divert, drain and dispose of water. To do this they use interceptor ditches and slopes,road crowns, and ditch and culvert systems.
Divert —Interceptor ditches, located between the road and higher ground along the road, keep the water from reaching the roadway. These ditches must slope so they carry water away from the road.
Drain —Creating a crown in the road so it is higher along the centerline than at the edges encourages water to flow off the road. Typically a paved crown should be 1?4" higher than the shoulder for each foot of width from the centerline to the edge. For gravel surfaces the crown
should be 1?2" higher per foot of width. For this flow path to work, the road surface must be relatively water tight. Road shoulders also must be sloped away from the road to continue carrying the flow away. Superelevations (banking) at the outside of curves will also help drain
the road surface.
Dispose —A ditch and culvert system carries water away from the road structure. Ditches should be at least one foot lower than the bottom of the gravel road layer that drains the roadway. They must be kept clean and must be sloped to move water into natural drainage. If water stays in the ditches it can seep back into the road structure and undermine its strength. Ditches should also be protected from erosion by planting grass, or installing rock and other erosion control measures. Erosion can damage shoulders and ditches, clog culverts, undermine roadbeds, and contaminate nearby streams and lakes. Evaluate your ditch and culvert system twice a year to ensure that it works. In the fall, clean out leaves and branches that can block flow. In spring, check for and remove silts from plowing and any dead plant material left from the fall.
2．Build on a firm foundation
A road is only as good as its foundation. A highway wears out from the top down but falls apart from the bottom. The road base must carry the entire structure and the traffic that uses it.
To make a firm foundation you may need to stabilize the roadbed with chemical stabilizers, large stone called breaker run, or geotextile fabric. When you run into conditions where you suspect that the native soil is unstable, work with an engineer to investigate the situation and design an appropriate solution.
3．Use the best materials
With all road materials you “pay now or pay later.” Inferior materials may require extensive maintenance throughout the road’s life. They may also force you to replace the road prematurely.
Crushed aggregate is the best material for the base course. The sharp angles of thecrushed material interlock when they are compacted. This supports the pavement and traffic by transmitting the load from particle to particle. By contrast, rounded particles act like ball
bearings, moving under loads.
Angular particles are more stable than rounded particles.
Asphalt and concrete pavement materials must be of the highest quality, designed for
the conditions, obtained from established firms, and tested to ensure it meets specifications.
4．Compact all layers
In general, the more densely a material is compacted, the stronger it is. Compaction also shrinks or eliminates open spaces (voids) between particles. This means that less water can enter the structure. Water in soil can weaken the structure or lead to frost heaves. This is especially important for unsurfaced (gravel) roads. Use gravel which has a mix of sizes (well-graded aggregate) so smaller particles can fill the voids between larger ones. Good
compaction of asphalt pavement lengthens its life.
5．Design for traffic loads and volumes
Design for the highest anticipated load the road will carry. A road that has been designed only for cars will not stand up to trucks. One truck with 9 tons on a single rear axle does as much damage to a road as nearly 10,000 cars.
Rural roads may carry log trucks, milk trucks, fire department pumper trucks, or construction equipment. If you don’t know what specific loads the road w ill carry, a good rule of thumb is to design for the largest piece of highway maintenance equipment that will be used on the road.
A well-constructed and maintained asphalt road should last 20 years without major repairs or reconstruction. In designing a road, use traffic counts that project numbers and sizes of vehicles 20 years into the future. These are only projections, at best, but they will allow you to plan for traffic loadings through a road’s life.
6．Design for maintenance
Without maintenance a road will rapidly deteriorate and fail. Design your roads so they can be easily maintained. This means:
? adequate ditches that can be cleaned regularly
? culverts that are marked for easy locating in the spring
? enough space for snow after it is plowed off the road
? proper cross slopes for safety, maintenance and to avoid snow drifts
? roadsi des that are planted or treated to prevent erosion
? roadsides that can be mowed safely
A rule of thumb for adequate road width is to make it wide enough for a snowplow to pass another vehicle without leaving the travelled way.
Mark culverts with a post so they can be located easily.
7．Pave only when ready
It is not necessary to pave all your roads immediately. There is nothing wrong with a well-built and wellmaintained gravel road if traffic loads and volume do not require a paved surface. Three hundred vehicles per day is the recommended minimum to justify paving.
Don’t assume that laying down asphalt will fix a gravel road that is failing. Before you
pave, make sure you have an adequate crushed stone base that drains well and is properly compacted. The recommended minimum depth of crushed stone base is 10" depending on subgrade soils. A road paved only when it is ready will far outperform one that is constructed too quickly.
8．ê Build from the bottom up
This commandment may seem obvious, but it means that you shouldn’t top dress or resurface a road if the problem is in an underlying layer. Before you do any road improvement, locate the cause of any surface problems. Choose an improvement technique that will address the problem. This may mean recycling or removing all road materials down to the native soil and rebuilding everything. Doing any work that doesn’t solve the problem is a waste of money and effort.
9．ê Protec t your investment
The road system can be your municipality’s biggest investment. Just as a home needs painting or a new roof, a road must be maintained. Wisconsin’s severe climate requires more road maintenance than in milder places. Do these important maintenance activities: Surface —grade, shape, patch, seal cracks, control dust, remove snow and ice
Drainage —clean and repair ditches and culverts; remove all excess material
Roadside —cut brush, trim trees and roadside plantings, control erosion
Traffic service —clean and repair or replace signs
Design roads with adequate ditches so they can be maintained with a motor grader. Clean and grade ditches to maintain proper pitch and peak efficiency. After grading, remove all excess material from the shoulder.
10．Keep good records
Your maintenance will be more efficient with good records. Knowing the road’s construction, life, and repair history makes it much easier to plan and budget its future repairs. Records can also help you evaluate the effectiveness of the repair methods and materials you used.
Good record keeping starts with an inventory of the system. It should include the history and surface condition of the roadway, identify and evaluate culverts and bridges, note ditch conditions, shoulders, signs, and such structures as retaining walls and guardrails.
Update your inventory each year or when you repair or change a road section. A formal pavement management system can help use these records and plan and budget road improvements.
Resources
The Basics of a Good Road#17649, UW-Madison, 15 min. videotape. Presents
the Ten Commandments of a Good Road. Videotapes are loaned free through County Extension offices.
Asphalt PASER Manual(39 pp), Concrete PASER Manual (48 pp), Gravel PASER
Manual (32 pp). These booklets contain extensive photos and descriptions of road surfaces to help you understand types of distress conditions and their causes. A simple procedure for rating the condition helps you manage your pavements and plan repairs.
Roadware, a computer program which stores and reports pavement condition
information. Developed by the Transportation Information Center and enhanced by the Wisconsin Department of Transportation, it uses the PASER rating system to provide
five-year cost budgets and roadway repair/reconstruction priority lists.
Wisconsin Transportation Bulletin factsheets, available from the Transportation Information Center (T.I.C.).
Road Drainage, No. 4. Describes drainage for roadways, shoulders, ditches, and culverts.
Gravel Roads, No. 5. Discusses the characteristics of a gravel road and how to maintain one.
Using Salt and Sand for Winter Road Maintenance,No. 6. Basic information and practical tips on how to use de-icing chemicals and sand.
Culverts—Proper Use and Installation, No. 15. Selecting and sizing culverts, designing, installing and maintaining them.
Geotextiles in Road Construction/Maintenance and
Erosion Control, No. 16. Definitions and common applications of geotextiles on
roadways and for erosion control.
T.I.C. workshops are offered at locations around the state.
Crossroads,an 8-page quarterly newsletter published by the T.I.C. carries helpful
articles, workshop information, and resource lists. For more information on any of these materials, contact the T.I.C. at 800/442-4615.
中文译文
一个良好的公路的基础
长久以来我们已经掌握了如何铺设好一条道路的方法，考古学家发现在4600年古埃及使用建造金字塔的石块铺设道路，后来，罗马人使用同样的方法建立了一个庞大的道路系统，这种方法一直沿用到今天。其中的某些道路依然发挥着作用。
如果我们遵照到路的基本概念铺设，将会建设一条持久耐用的道路。以下是铺设好一条道路的十点要求：
(1) 尽量做好道路的排水
(2) 路基的基础一定要稳固
(3) 选用经济合理的铺设材料
(4) 铺设的层次要紧凑合理
(5) 设计好道路的最大车辆荷载
(6) 做好设计维护
(7) 准备工作做好才能铺设
(8) 铺设从下往上开始
(9) 预算好您的投资
(10)保持良好的记录
1．尽量做好道路的排水
我们在怎么强调排水的重要性也不为过，工程师估计，至少有90％的道路的问题可能与过量的道路积水或劣质的排水设施有关。过多的水积攒在道路的结构层内，这样会减弱结构层与基层的稳定性，从而导致路基的破坏。在道路的面层，水分可能引起路面开裂和裂缝内积水。在基层将引起基层的支撑能力下降导致基层的破坏，会出现裂缝和坑洞。积水的一个共同的标志是沥青路面开裂是龟裂的—裂缝彼此之间相互关联，形成不规则的小块看起来像鳄鱼皮。边缘的裂缝，热胀冷缩，春季路面解冻的问题。为了防止此类的问题持续：
（1）水顺边坡下流
（2）排到必要的地方
（3）如果水分不能排出就会引起问题。
有效的排水系统，水分的排出和处置。为此，他们利用拦截沟渠和斜坡，道路冠冕，沟
渠和涵洞系统。
转移--拦截沟渠，坐落在道路和路线较高的位置，从而使水能够远离道路。这些排水沟与边坡能够将水分及时排走。
排水--建立在路上一顶王冠，因此沿中心线高于在边缘鼓励水流过马路。通常，铺设冠应该是1 / 4每页宽度脚高于“每个中心线的宽度从山脚到边缘的肩膀。砾石表面的冠应该是1 / 2高”。为此流路的工作，路面必须相对水密。路肩还必须远离公路倾斜，继续承载着流走。Superelevations在曲线外（银行）也将有助于drainthe路面。
处理—水沟，涵洞系统进行水离路面结构。沟渠应至少有一个脚比的砾石层，道路排水巷道底低。他们必须保持清洁，必须倾斜迁入自然排水。如果在沟渠的水留它可以渗透回道路结构和削弱其力量。沟渠也应受到保护不受侵蚀，种植草，或安装岩石和其他水土保持措施。侵蚀可以破坏的肩膀和沟渠，堵塞涵洞，破坏路基，并污染附近的河流和湖泊。
评估你的沟渠和涵洞制度，每年两次，以确保它可以工作。到了秋天，树叶和树枝清理掉，可以阻止流动。在春天，检查并清除耕耘任何死去的植物材料，从秋天离开淤泥。
2．路基的基础一定要稳固
阿路也只有在良好的基础。一条公路穿从上而下，但瀑布从底部分开。道路基础必须进行整个结构和交通使用它。为了使一个坚实的基础，你可能需要用化学稳定剂，稳定路基，大石头叫断路器运行，或土工织物。当你遇到条件下您怀疑乡土是不稳定的，具有工程师，调查有关情况，并设计一个适当的解决办法的工作。
3．选用经济合理的铺设材料
所有道路材料的你“，现在或以后付工资。”劣质材料可能需要在整个公路的生命进行大规模维修。他们也可能迫使你以取代道路过早。人工砂石料是为基层的最佳材料。在粉碎物料互锁锐角时，他们都将被压缩。这支持通过传输负载从粒子与粒子之间的路面和交通。相比之下，像圆颗粒球轴承，在外力作用下的运动。
沥青混凝土路面材料必须是最高质量的公司从成立的条件下获得的，设计和测试，以确保其符合规格。
4．铺设的层次要紧凑合理
在一般情况下，更密集的物质被压缩，这是越强。缩小或消除压实也粒子间空地（空隙）。这意味着更少的水可以进入的结构。土壤中水的结构可以削弱或导致霜冻眼帘。这对于unsurfaced（砾石）道路重要。使用砾石其中有一个尺寸（良好级配碎石）的组合，以便更小的颗粒可以填补较大的空隙之间。好
沥青路面压实延长其寿命。
5．设计好道路的最大车辆荷载
设计最高负荷预计将进行的道路。一个是专为汽车的必由之路不会站起来卡车。9吨卡车之一，在一个后轴不以道路为近万汽车造成很大损害。
农村道路可能携带日志卡车，牛奶车，消防部门消防车卡车，或施工设备。如果你不知道什么具体的道路将进行加载，一个好的经验法则是，设计为公路养护设备的最大一块将在道路上使用。
一个良好的构造和维修沥青路面应持续无大修或重建20年。道路设计，使用交通计数的项目数量和20年到未来车辆的大小。这些仅仅是预测，在最好的，但他们将允许您计划穿越道路交通负荷的生活。
6．做好设计维护
无需维修道路将会迅速恶化并失败。设计你的道路，让他们可以很容易地维持。这意味着：可以定期清理沟渠充足
?以方便用户在春季定位标记暗渠
?雪足够的空间是翻耕后离开道路
?恰当的安全，维修斜坡，避免交叉雪堆
?是种植或处理，以防止水土流失路旁
?可安全地修剪路旁
一个拇指规则是足够的道路宽度，使其足够宽的扫雪机通过旅行方式，而不必离开其他车辆。7．准备工作做好才能铺设
这是没有必要所有的道路铺平立即。有一个精心打造和wellmaintained砂石路没有什么错的交通负荷及数量不需要铺设表面。每天三百辆是建议的最低证明铺路。
不要以为铺设沥青碎石路面修复将是失败的。在您铺平，请确保您有足够的基础，碎石排水良好，适当压缩。推荐的碎石基层的最低深度为10“路基土壤而定。
阿铺平道路时，才愿意将远远超越一个是构建太快
8．铺设从下往上开始
这似乎是显而易见的命令，但它意味着你不应该顶服饰或重铺道，如果问题出在一个基础层。在你做任何道路改善，找到任何表面问题的原因。选择一个改进技术，以解决问题。这可能意味着回收或清除所有道路材料到原生的土壤和重建。做任何工作，不解决问题是一种对金钱和精力的浪费。
9．预算好您的投资
道路系统可以是您的全市最大的投资。就像一个家庭需要油漆或一个新的屋顶，道路必须维持。威斯康星州的严重环境要求较温和的地方道路维修。做这些重要的保养活动：（1）表面-等级，形状，修补，密封裂缝，控制粉尘，消除冰雪
（2）渠- 清理和修复沟渠，涵洞;清除所有多余的材料
（3）路边- 切刷，修剪树木和路边种植面积，控制水土流失
（4）交通服务- 清洁和修理或更换的迹象
10．保持良好的记录
您的维护将更加具有良好的记录效率。知道了道路的建设，生活和修复历史让我们更容易的未来计划和预算
维修。记录也可以帮助您评估的修复方法和材料您使用的有效性。
保持良好的记录与库存系统的一个开始。它应包括巷道的历史和表面状况，确定和评估涵洞和桥梁，注意沟条件，肩膀，标牌，并作为挡土墙及护栏等结构。
更新您的库存，每年或当您修理或更换路段。一个正式的路面管理系统可以帮助使用这些记录，计划和预算道路改善工程。
资源
一个良好的路＃17649，威斯康星大学麦迪逊分校，15分钟的基础知识。录像带。介绍了良好的道路十诫。免费租借录像带是通过县推广部门。
沥青PASER手册（39页），具体PASER手册（48页），砂石PASER手册（32页）。这些小册子包含大量的照片和路面描述来帮助你理解窘迫状况及其原因的类型。一个简单的程序，评级的条件可以帮助您管理您的人行道和计划修理。
Roadware，计算机存储和报告方案，路面状况的信息。公司开发的交通信息中心和威斯康星州的交通运输部加强，它使用PASER评级系统，提供为期五年的成本预算和道路修复/重建的优先名单。
从交通信息中心（TIC）获得威斯康星州的交通情况说明公告，。道路排水描述用于道路排水，肩膀，沟渠，涵洞。碎石路讨论了砾石路面的特点和如何维护之一，包括利用冬季道路养护盐和沙子及如何使用除冰化学品和沙子的实用技巧。涵洞的正确使用和安装，选择和大小涵洞，设计，安装和维护它们。土工织物在道路建设/维护和侵蚀控制，定义和常见的应用土工布在道路和控制水土流失。
红外数据通信技术外文翻译文献(文档含中英文对照即英文原文和中文翻译) Infrared Remote Control System Abstract Red outside data correspondence the technique be currently within the scope of world drive extensive usage of a kind of wireless conjunction technique, drive numerous hardware and software platform support. Red outside the transceiver product have cost low, small scaled turn, the baud rate be quick, point to point SSL, be free from electromagnetism thousand Raos
etc. characteristics, can realization information at dissimilarity of the product fast, convenience, safely exchange and transmission, at short distance wireless deliver aspect to own very obvious of advantage. Along with red outside the data deliver a technique more and more mature, the cost descend, red outside the transceiver necessarily will get at the short distance communication realm more extensive of application. The purpose that design this system is transmit customer’s operation information with infrared rays for transmit media, then demodulate original signal with receive circuit. It use coding chip to modulate signal and use decoding chip to demodulate signal. The coding chip is PT2262 and decoding chip is PT2272. Both chips are made in Taiwan. Main work principle is that we provide to input the information for the PT2262 with coding keyboard. The input information was coded by PT2262 and loading to high frequent load wave whose frequent is 38 kHz, then modulate infrared transmit dioxide and radiate space outside when it attian enough power. The receive circuit receive the signal and demodulate original information. The original signal was decoded by PT2272, so as to drive some circuit to accomplish customer’s operation demand. Keywords: Infrared dray；Code；Decoding；LM386；Red outside transceiver 1 Introduction 1.1 research the background and significance Infrared Data Communication Technology is the world wide use of a wireless connection technology, by the many hardware and software platforms supported. Is a data through electrical pulses and infrared optical pulse switch between the wireless data transceiver technology.
PA VEMENT PROBLEMS CAUSED BY COLLAPSIBLE SUBGRADES By Sandra L. Houston,1 Associate Member, ASCE (Reviewed by the Highway Division) ABSTRACT: Problem subgrade materials consisting of collapsible soils are com- mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation. Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils. A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented. Relatively simple methods of evaluating potential volume change, based on results of familiar laboratory tests, are used. INTRODUCTION When a soil is given free access to water, it may decrease in volume, increase in volume, or do nothing. A soil that increases in volume is called a swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil. The amount of volume change that occurs depends on the soil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting. Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be- ginning of the professional practice and have cost many millions of dollars in roadway repairs. The prediction of the volume changes that may occur in the field is the first step in making an economic decision for dealing with these problem subgrade materials. Each project will have different design considerations, economic con- straints, and risk factors that will have to be taken into account. However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, and a much more rational design approach may be made. For example, typical techniques for dealing with expansive clays include: (1) In situ treatments with substances such as lime, cement, or fly-ash; (2) seepage barriers and/ or drainage systems; or (3) a computing of the serviceability loss and a mod- ification of the design to "accept" the anticipated expansion. In order to make the most economical decision, the amount of volume change (especially non- uniform volume change) must be accurately estimated, and the degree of road roughness evaluated from these data. Similarly, alternative design techniques are available for any roadway problem. The emphasis here will be placed on presenting economical and simple methods for: (1) Determining whether the subgrade materials are collapsible; and (2) estimating the amount of volume change that is likely to occur in the 'Asst. Prof., Ctr. for Advanced Res. in Transp., Arizona State Univ., Tempe, AZ 85287. Note. Discussion open until April 1, 1989. To extend the closing date one month,
中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。
The smart grid Smart grid is the grid intelligent (electric power), also known as the "grid" 2.0, it is based on the integration, high-speed bidirectional communication network, on the basis of through the use of advanced sensor and measuring technology, advanced equipme nt technology, the advanced control method, and the application of advanced technology of decision support system, realize the power grid reliability, security, economic, efficient, environmental friendly and use the security target, its main features include self-healing, incentives and include user, against attacks, provide meet user requirements of power quality in the 21st century, allow all sorts of different power generation in the form of access, start the electric power market and asset optimizatio n run efficiently. The U.S. department of energy (doe) "the Grid of 2030" : a fully automated power transmission network, able to monitor and control each user and power Grid nodes, guarantee from power plants to end users among all the nodes in the whole process of transmission and distribution of information and energy bi-directional flow. China iot alliance between colleges: smart grid is made up of many parts, can be divided into:intelligent substation, intelligent power distribution network, intelli gent watt-hourmeter,intelligent interactive terminals, intelligent scheduling, smart appliances, intelligent building electricity, smart city power grid, smart power generation system, the new type of energy storage system.Now a part of it to do a simple i ntroduction. European technology BBS: an integration of all users connected to the power grid all the behavior of the power transmission network, to provide sustained and effective economic and security of power. Chinese academy of sciences, institute of electrical: smart grid is including all kinds of power generation equipment, power transmission and distribution network, power equipment and storage equipment, on the basis of the physical power grid will be modern advanced sensor measurement technology, network technology, communication
用于多跳认知无线电网络的分布式网络编码控制信道 Alfred Asterjadhi等著 1 前言 大多数电磁频谱由政府机构长期指定给公司或机构专门用于区域或国家地区。由于这种资源的静态分配，许可频谱的许多部分在许多时间和/或位置未使用或未被充分利用。另一方面，几种最近的无线技术在诸如IEEE802.11，蓝牙，Zigbee之类的非许可频段中运行，并且在一定程度上对WiMAX进行操作;这些技术已经看到这样的成功和扩散，他们正在访问的频谱- 主要是2.4 GHz ISM频段- 已经过度拥挤。为了为这些现有技术提供更多的频谱资源，并且允许替代和创新技术的潜在开发，最近已经提出允许被许可的设备（称为次要用户）访问那些许可的频谱资源，主要用户未被使用或零星地使用。这种方法通常被称为动态频谱接入（DSA），无线电设备发现和机会性利用未使用或未充分利用的频谱带的能力通常称为认知无线电（CR）技术。 DSA和CR最近都引起了无线通信和网络界的极大关注。通常设想两种主要应用。第一个是认知无线接入（CW A），根据该认知接入点，认知接入点负责识别未使用的许可频谱，并使用它来提供对次用户的接入。第二个应用是我们在这个技术中研究的应用，它是认知自组织网络（CAN），也就是使用 用于二级用户本身之间通信的无许可频谱，用于诸如点对点内容分发，环境监控，安全性等目的，灾难恢复情景通信，军事通信等等。 设计CAN系统比CW A有更多困难，主要有两个原因。第一是识别未使用的频谱。在CW A中，接入点的作用是连接到互联网，因此可以使用简单的策略来推断频谱可用性，例如查询频谱调节器在其地理位置的频谱可用性或直接与主用户协商频谱可用性或一些中间频谱经纪人另一方面，在CAN中，与频谱调节器或主要用户的缺乏直接通信需要二级用户能够使用检测技术自己识别未使用的频谱。第二个困难是辅助用户协调媒体访问目的。在CW A中存在接入点和通常所有二级用户直接与之通信（即，网络是单跳）的事实使得直接使用集中式媒体接入控制（MAC）解决方案，如时分多址（TDMA）或正交频分多址（OFDMA）。相反，预计CAN将跨越多跳，缺少集中控制器;而对于传统的单通道多跳自组织网络而言，这个问题的几个解决方案是已知的，因为假设我们处理允许设备访问的具有成
姓名： 学号： 10447425 X X 大学 毕业设计（论文）外文翻译 （2014届） 外文题目Developments in excavation bracing systems 译文题目开挖工程支撑体系的发展 外文出处Tunnelling and Underground Space Technology 31 (2012) 107–116 学生XXX 学院XXXX 专业班级XXXXX 校内指导教师XXX 专业技术职务XXXXX 校外指导老师专业技术职务 二○一三年十二月
开挖工程支撑体系的发展 1.引言 几乎所有土木工程建设项目（如建筑物，道路，隧道，桥梁，污水处理厂，管道，下水道）都涉及泥土挖掘的一些工程量。往往由于由相邻的结构，特性线，或使用权空间的限制，必须要一个土地固定系统，以允许土壤被挖掘到所需的深度。历史上，许多挖掘支撑系统已经开发出来。其中，现在比较常见的几种方法是：板桩，钻孔桩墙，泥浆墙。 土地固定系统的选择是由技术性能要求和施工可行性（例如手段，方法）决定的，包括执行的可靠性，而成本考虑了这些之后，其他问题也得到解决。通常环境后果（用于处理废泥浆和钻井液如监管要求）也非常被关注（邱阳、1998）。 土地固定系统通常是建设项目的较大的一个组成部分。如果不能按时完成项目，将极大地影响总成本。通常首先建造支撑，在许多情况下，临时支撑系统是用于支持在挖掘以允许进行不断施工，直到永久系统被构造。临时系统可以被去除或留在原处。 打桩时，因撞击或振动它们可能会被赶入到位。在一般情况下，振动是最昂贵的方法，但只适合于松散颗粒材料，土壤中具有较高电阻（例如，通过鹅卵石）的不能使用。采用打入桩系统通常是中间的成本和适合于软沉积物（包括粘性和非粘性），只要该矿床是免费的鹅卵石或更大的岩石。 通常，垂直元素（例如桩）的前安装挖掘工程和水平元件（如内部支撑或绑回）被安装为挖掘工程的进行下去，从而限制了跨距长度，以便减少在垂直开发弯矩元素。在填充情况下，桩可先设置，从在斜坡的底部其嵌入悬挑起来，安装作为填充进步水平元素（如搭背或土钉）。如果滞后是用来保持垂直元素之间的土壤中，它被安装为挖掘工程的进行下去，或之前以填补位置。 吉尔- 马丁等人（2010）提供了一个数值计算程序，以获取圆形桩承受轴向载荷和统一标志（如悬臂桩）的单轴弯矩的最佳纵筋。他们开发的两种优化流程：用一个或两个直径为纵向钢筋。优化增强模式允许大量减少的设计要求钢筋的用量，这些减少纵向钢筋可达到50％相对传统的，均匀分布的加固方案。 加固桩集中纵向钢筋最佳的位置在受拉区。除了节约钢筋，所述非对称加强钢筋图案提高抗弯刚度，通过增加转动惯量的转化部分的时刻。这种增加的刚性可能会在一段时间内增加的变形与蠕变相关的费用。评估相对于传统的非对称加强桩的优点，对称，钢筋桩被服务的条件下全面测试来完成的，这种试验是为了验证结构的可行性和取得的变形的原位测量。 基于现场试验中，用于优化的加强图案的优点浇铸钻出孔（CIDH）在巴塞罗那的
New technique of the computer network Abstract The 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the people's work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application. keywords Internet Network System Digital Certificates Grid Storage 1. Foreword Internet turns 36, still a work in progress Thirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress. University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce Spam (junk mail) and security troubles. All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today. Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Klein rock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other "nodes" joined the fledgling network.
Computer Program 1 Introduction Computer Program, set of instructions that directs a computer to perform someprocessing function or combination of functions. For the instructions to be carried out, a computer must execute a program, that is, the computer reads the program, and then follow the steps encoded in the program in a precise order until completion. A program can be executed many different times, with each execution yielding a potentially different result depending upon the options and data that the user gives the computer. Programs fall into two major classes: application programs and operating systems. An application program is one that carries out somefunction directly for a user, such as word processing or game-playing. An operating system is a program that manages the computer and the various resources and devices connected to it, such as RAM,hard drives, monitors, keyboards, printers, and modems,so that they maybe used by other programs. Examples of operating systems are DOS, Windows 95, OS\2, and UNIX. 2 Program Development Software designers create new programs by using special applications programs, often called utility programs or development programs. A programmer uses another type of program called a text editor to write the new program in a special notation called a programming language. With the text editor, the programmer creates a text file, which is an ordered list of instructions, also called the program source file. The individual instructions that make up the program source file are called source code. At this point, a special applications program translates the source code into machine language, or object code— a format that the operating system
5G无线通信网络中英文对照外文翻译文献(文档含英文原文和中文翻译)
翻译： 5G无线通信网络的蜂窝结构和关键技术 摘要 第四代无线通信系统已经或者即将在许多国家部署。然而，随着无线移动设备和服务的激增，仍然有一些挑战尤其是4G所不能容纳的，例如像频谱危机和高能量消耗。无线系统设计师们面临着满足新型无线应用对高数据速率和机动性要求的持续性增长的需求，因此他们已经开始研究被期望于2020年后就能部署的第五代无线系统。在这篇文章里面，我们提出一个有内门和外门情景之分的潜在的蜂窝结构，并且讨论了多种可行性关于5G无线通信系统的技术，比如大量的MIMO技术，节能通信，认知的广播网络和可见光通信。面临潜在技术的未知挑战也被讨论了。 介绍 信息通信技术（ICT）创新合理的使用对世界经济的提高变得越来越重要。无线通信网络在全球ICT战略中也许是最挑剔的元素，并且支撑着很多其他的行业，它是世界上成长最快最有活力的行业之一。欧洲移动天文台（EMO）报道2010年移动通信业总计税收1740亿欧元,从而超过了航空航天业和制药业。无线技术的发展大大提高了人们在商业运作和社交功能方面通信和生活的能力无线移动通信的显著成就表现在技术创新的快速步伐。从1991年二代移动通信系统(2G)的初次登场到2001年三代系统（3G）的首次起飞，无线移动网络已经实现了从一个纯粹的技术系统到一个能承载大量多媒体内容网络的转变。4G无线系统被设计出来用来满足IMT-A技术使用IP面向所有服务的需求。在4G系统中，先进的无线接口被用于正交频分复用技术（OFDM），多输入多输出系统（MIMO）和链路自适应技术。4G无线网络可支持数据速率可达1Gb/s的低流度，比如流动局域无线访问，还有速率高达100M/s的高流速，例如像移动访问。LTE系统和它的延伸系统LTE-A，作为实用的4G系统已经在全球于最近期或不久的将来部署。 然而，每年仍然有戏剧性增长数量的用户支持移动宽频带系统。越来越多的
（ 二 〇 一 二 年 六 月 外文文献及翻译 题 目： About Buiding on the Structure Design 学生姓名： 学 院：土木工程学院 系 别：建筑工程系 专 业：土木工程(建筑工程方向) 班 级：土木08-4班 指导教师：
英文原文： Building construction concrete crack of prevention and processing Abstract The crack problem of concrete is a widespread existence but again difficult in solve of engineering actual problem, this text carried on a study analysis to a little bit familiar crack problem in the concrete engineering, and aim at concrete the circumstance put forward some prevention, processing measure. Keyword:Concrete crack prevention processing Foreword Concrete's ising 1 kind is anticipate by the freestone bone, cement, water and other mixture but formation of the in addition material of quality brittleness not and all material.Because the concrete construction transform with oneself, control etc. a series problem, harden model of in the concrete existence numerous tiny hole, spirit cave and tiny crack, is exactly because these beginning start blemish of existence just make the concrete present one some not and all the characteristic of quality.The tiny crack is a kind of harmless crack and accept concrete heavy, defend Shen and a little bit other use function not a creation to endanger.But after the concrete be subjected to lotus carry, difference in temperature etc. function, tiny crack would continuously of expand with connect, end formation we can see without the
英文翻译 A comprehensive overview of substations Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of power’s transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life. Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the country's economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability,