英文翻译

第一篇：英文翻译

Adjustment shaft and turning in vertical

hydro-generator unit

Keywords: electric turning;Mechanical turning;Place degree;Hydro-generator unit;Axis;Upper guide bearing;Lower guide bearing;Water bearing;Flange;

Pick to: reduce the error of axial line, reduce the unit operation axis of rotating components unbalance force, is an important work in installation and manufacturing.The existence of all connected components unit manufacture and installation of the error, making the unit the main axis(ie the spindle centerline)and its rotation does not coincide with the center line of the existence of different degrees of tilt or turns.Unit assembly, should be adjusted vertically that mirror surface and unit axis, make the unit set degrees in the range of allowable values and ensure its stable and reliable operation.Unit pendulum degrees size is measured the unit manufacture and installation quality of the main indexes.The purpose is to inspect the car plate tilt and Twists status of the unit axis, through the plate for car measurement data analysis and processing axis, the bearing, reasonably determine the center position.A.hydro-generating dish car technology

Car hydro-generating plate can be roughly divided into human turning, machinery turning, electric turning.In practical work according to the units installed model, size, and through the calculated plate for traction, we can develop programs and select the way of turning.1.Turning conditions

Before turning we should make sure the purpose, second select the way of turning, and then make plane for operation.No matter that turning, hydro-generating unit shall meet the following conditions.(1)Try to adjust thrust bearing watts of stress, make all tile surface stress

basic even, and make lens board on the horizontal state.Under the on guide

and the nextto ensure that there is at least $4 watts respectively with sliding

axial clearances between is 0.05 mm to control the radial displacement of the

spindle , thereby ensuring the whole hydraulic turbines fluctuation with turning

more easily.(2)Carefully check the gap of each fixed and rotating parts, should ensure

internal without sundry legacy.Generator rotor clearance circle with a white

cloth with a drawing.Turbine impeller round with feeler checked again.Do lens

board and each tile face clean and already has lubricating conditions.(3)Other related work ended.Machine Pit drain pump is on, brake

shoes is off.Grinding tungsten watts face when watts with lard or other high

anti-wear lubricant such as “times force”;And, after falling in avoiding within

the shortest possible time began to dish car.Have high pressure oil jacked up

device of tungsten watts unit disk into high pressure oil front should be jacked

up.(4)After the end of rotor slip ring installation, and brush frame install and

adjust well, next we can do the electric turning.Generator field circuit and

spare field device, stator qualification turning and turning attachment is to

picked well, stator rotor with transmission conditions

.2.Traction calculation

The friction of rotating parts compared to thrust watts and lens board is

small, so only consider the latter.We define it as 'F.'F-G*f G is the weight of rotational part(KN).The f is friction coefficient

(0.05-0.15)

Friction to center arm refers to turn in lens board average point of friction,namely the diameter D thrust watts average diameter.So friction torque

M '= F G.F.D.Traction F = G*F*D/R*N.R is the radius of the towing point to the rotation

center, N is the number of traction point.3.Human turning

Usually it is used in small units.On the shaft, or the thrust collar fixed a

turning device.We will achieve the purpose of turning by exerting push pull

unit rotation via leveraged tool,4.Machinery turning

Mechanical turning is a way of turning which makes the thrust collar or

rotor rotating applied by the mechanical traction.We should also decorate

pulleys and plate frame or turning column at site,.Usually bridge imposes

thetraction.If the rope tension of bridge machine is greater than the static friction

torque thrust , the hydro-generator unit will turn up slowly.So it comes ture that

the purpose of turning.5.Electric turning

Electric turning depends on the equipment of electric turning, with the

stator and the rotor windings accessed to DC.we can pass each phase of the

Stator into the current to make the rotor rotating.Next we can achieve the

purpose of turning.When the generator rotor winding with constant dc, general

each pole will produce a constant filed, thus between the air-gap and the stator

core will produce a constant flux.At the same time if the stator single-phase

also ventilation with DC, the phase bar will be clockwise(or anti clockwise)

because of magnetic force.According to the magnetic force and reaction

principle, the rotor will be drived clockwise(or clockwise).If the magnetic

rotation is greater than that of the rotor produced the static friction torque M ',then the rotor will turn 120 °electric horns.Then we switch the current to

another phase of the stator, rotor going on another 120 ° electric horn.Three-phase circulation switching, rotor can be continuous rotation.B.unit axis adjustments

Suspended hydro-generator often adopts the structure of Turbine shaft

and Generator shaft directly connected at present.The umbrella units often

adopt top shaft, hydrogenerator rotor huband turbine shaft linking structure.If thrust bearing lens board with axis is not vertical axis tilt will appear;if the

combinative position of two flanges and axis is not vertical axis twists will

appear.Axis tilt and tortuous there is large when the unit operating, will appear

larger pendulum degrees.Next there will appear whole periodic mechanical

strength between thrust bearing and guide bearing, maybe it also cause

greater magnetic and hydraulic unbalance force, causing the unit operation is

not in steady state.1.The method of measuring the axis

1.1Generally high-point of guide bearing acting as the fulcrum, limit by

crane traction thrust collar or rotor rotating machinery plate car or through

electric dish axis measurement method for measuring axis, the general is

above guide limit for fulcrum, through the crane traction thrust head or rotor

rotating machinery plate car or through electric car equipment and the

appointed disk in dc, rotor winding, and aerated stator points of interlinked

rotor rotating electrical control method, on electric dish car in the week of

turning unit spindle stay at 8 presses divide, and be consistent, dish and point

at each axis car to push up, down, left and right, point, big axis should be in an

axial free state, at the same time use the repose upon(X, Y direction)set slip

ring each piece, guide, guide, flange, water under the guide of the place such

as measuring the pendulum degrees batches, values, in general to dish to

check numerical twice.Thus can be obtained for thrust mirror axis is not

perpendicular and flange place for axis processing twists, turns and provides

the basis.The measured data of disc arrangement, car by drawing feudals put

degrees curve for good, drawn to scale, but the level of axis projection display

feudals put degrees directly maximum azimuth and numerical, convenience in

axis processing calculation.1.2Hydro-generator unit of thrust bearing rigid strut, its axis should meet

the “Specification for installation of hydro-generator unit ”（GB8564-88）.If

axis tilt andtwists excess the range of rating, it is qualified.We must adjust the

axis to the allowed.1.3Hydro-generator unit of hydraulic pillar type thrust bearings, due to

the hydropower units having automatic adjustment pushing force watts, the

ability to force requirements of unit axis have been relaxed.But for hydraulic

pillar type thrust bearings installation requirements is very strict.By adjusting

stents or base of the thrust, the levelness of the lens board mirror shall not be

more than 0.02 mm/m, and when rfinally the unit rotating components is in unit

center, by the way of Increasing or decreasing reduction of each rotor elastic

oil tank, its biggest compression value deviation should be no greater than

0.20 mm for qualified.Its use is the so-called “elastic tutning” and called fore

each elastic oil tank under the condition of force adjusted qualified, we are

going to move rotational parts of the unit to the center.Then we should fixe the

upper guide bearing, lower guide bearing and water guide on the shaft, on

condition that the axial gap adjusted to 0.05 mm, turning is begun.Edge of

thrust runner collar by the axial swing shall not exceed the range of provisions

in GB8564-88.2.The axis of treatment

Neither thrust runner collar is vertical to generator axis nor flange winding

are more than prescribed value of theGB-8564-88,and installation, overhaul on

the condition of decompositing the flange, we should revise the axis both in

thrust and flange respectively.If the deal only with thrust runner collar, without

processing axis in twists, when turning and calculating position of the thrust

runner collar, consideration should be given to decreasing pendulum degrees

of the water guide bearing.Installating hydro-generator unit, we can also take measures of installation

and decompositing respectively.First execute the tutning of generators.Having

adjustmented generator axis, connect turbine shaft with turbine shaft.Then we

should processe the flange connected position and place a degrees

adjustment to qualified range.Thrust the processing,generally adopts the

Scraping method ,because it may obtain long time axis constant repairing

effect.Work can be directly done processing undersurface of thrust(no mat)or

scraping their combination between insulation plate surface.Practice shows

that the former to the latter achieves better results.Flange tortuous processing,can adopts the methord of the flange joint surface asked added pad or

scraping the flange joint surface.If scraping process is correct, no longer

changes appear after treatment generally.Scratch repair to determine the

amount and direction, according to the results drawn from the turning axis of

the horizontal projection obtained, repair scraped surface should be wedge,the actual steps to form the repair carried out by scraping.Add pad thickness

should be equal to the amount of repair scratch, but the direction is reversed.3.Axis adjustment

Axis adjustment refers to that unit rotational part center axis adjustmen

qualified.After adjustment, on one hand should make both generator stator

and rotor rotating center are Concentric ,and Turbine rotating center and the

turbine fixed stanch ring in a straight line;On the other hand, we should make

the thrust bearing force equilibrium, and the center of each trustbearing

watts cncentric.Afterwars ,make the unit rotational parts run around the unit

center.Accurate adjustment can not only obviously reduce magnetic

unbalance force of generator and turbine hydraulic imbalance force ,but also

make the vibrationand unit swing amplitude in good degree of standard range

with entirely mechanical force that bearing exerts

There are two kinds of cases of axis adjustment:

Following is the first.we should adjust both the position of axis by moving

the shaft, and force each thrust bearing tile bearing.At this time, due to the

adjustment Angle of the shaft rotation centerline, we can gain better

adjustment result.First, position of the shaft should have been moved before

adjustment , so that can easily make the generator rotor center and stator

center concentric, and then fixe top of the shaft on the upper guide bearing.By

adjusting each height of thrust bearing watts again, we can make the turbine

runner rotation center and the fixed labyrinth centercoincident.Meanwhile

adjust thrust each tile force beared uniform.Then we can calculate and adjust

bearing clearance with each other.Another kind is not to adjust the force each tile of thrust bearings.We just

adjust axis by moving the shaft.This kind of situation only on the condation

that center of the unit(it means that the stator center and turbine fixed stop

leakage ring is in a straight line)and angle of spindle centerline to satisfy the is

in the reasonable range.Then Axis adjustment can meet the requirements.Afterwards, as a reference to turbine fixed stanch ring , we can acheve the

purpose that center of rotation tunner and turbine fixed stanch ring is in a

straight line by moving shaft axis.Whether Axis adjustment is well done, it

depends that measurement of the generator air-gap and gap of hydraulic

labyrinth within the limits prescribed.

第二篇：英文翻译

Introduction: with the rapid development of the economy, China ‘smprehensive national power has been improved effectively.As a saying said;“Want to become rich first road”.So China has begun to build the high-speed rail since years ago.The building of the high~speed rail is suited to China's national conditions and help our country to run well in the strong competition of the world.大多数经济学家认为：交通基础设施的供应水平和能力必须适度超前，否则就会影响社会经济持续、稳定 和健康发展。这就意味着要加大对交通基础设施的投资，但是政府在加大交通基础设施投资力度的同时，用于改善民生的措施实际却在相对地减少。从中国目前的经济发展和人民的收入状况来说，我认为中国高 铁弊大于利.Most economists believe that: the supply and capability of transportation infrastructure must advance appropriately, otherwise it will affect the sustainable, stable and healthy development of social economy.This means that we have to increase the investment into transportation infrastructure,But while government increase the investment into transportation infrastructure, it will to some extent decrease the practical measures to improve people's livelihood.From China's current situation, I think it will do more harm than good to build high-speed railway in China.Piont1: Building too fast go against the laws of economic development, causing many problems, such as loan repayment, staff placement.And high-speed railway construction needs large investment, from the use of the actual situation, the possibility of short-term cost recovery do not, there is also the problem of capital wasting.建设速度过快，容易违背经济发展规律,同时面对的问题较多，例如贷款偿还，员工安置等。中国第一条高 铁客运专线——从北京到天津，它在 2008 年 8 月通车后一年就亏损了 7 个亿。武广高铁总投资约 1166 亿元，目前的线路至少能开 120 对车，但实际上只开了 33 对，而且还坐不满，这是资本的严重浪费。所 以说高铁建设不仅需要大笔的投资，而且从运用的实际的情况来看，短期收回成本的可能性根本就没有。The fast building speed will violate the rule of economic development, and at same time it faced many problems, such as loan repayment, staff placement.First high-speed railway of China-from Beijing to Tianjin, it was launched in August 2008, after one year it lossed 70 millions.The total investment of

Wuhan-Guangzhou high-speed rail was about 110 billions yuan, now it is able to drive at least 120 pairs of cars, but in fact only 33 to drive, and lots of seats are empty, this is a serious waste of capital.The high-speed railway not only requires large construction investment, but also, it is impossible to recovery the short-term cost based on its actural implement.Poiimnt2: The building of the high spee

d rail can drive the development of the industry related.for example, the building need many workers and the new technology, so it expand the employment and promiot the technological innovation.In another word through the building, more steel products are needed.Another important hand is transport during the Spring Festival.During this period of time, large numbers of people going home together.So the high speed rail can relieve the transportation pressure ectively 高铁的票价较高，例如京津高铁，它行驶 30 分钟，却要 69 元票价，让人望而生叹啊。中国的 GDP 总量 高居世界第二，但人均 GDP 在世界的排名却还在百名开外，穷人还是绝大多数。武广高铁开通后，原有 的一些客运列车停运，意味着中低收入者将被迫选择高铁，接受高票价。这种行为伤及了底层人民的最根 本利 e 而且建设过程中容易出现贪污腐败问题。The fare of high Speed Rail is higher, for example, the Beijing-Tianjin high-speed rail, it costs 69 yuan for only drive 30minuts.China's GDP ranks the second in the world, but per capita GDP still ranks out of hundreds in the world, the poor is the majority.When Wuhan-Guangzhou high-speed railway was used, the original passenger trains were stopped, which means low-incomer will be forced to choose high-speed rail and accept the high fares.This action has

impair interests of the low class people, and the corruption problem will be prone to easily during the process of building.新建高铁实际是在现有几种交通方式的基础上新增一种交通方式。建成之后会与高速公路、现有铁路、飞 机、船运形成竞争关系，在原有运力并不紧张的背景下必然形成运力过剩。新建的高铁主要是客运专线，因此高铁并不会加快货物与资金的周转速度，不会降低全社会运行成本。要修建如此庞大的高速铁路网，必将消耗大量的资金，必将挤占人们收入上涨的空间与企业利润空间（加重税负）如果将此财政投入医疗、。社保、教育、技术研究，则会消除人们存钱的预防养老动机从而扩大消费，利于中国经济可持续发展。综 上所述，在中国大规模修建高铁对中国经济的长远发展来讲是弊大于利，不利于扩大内需、不利于产业结 构调整 结论：The high-speed railway will compete with the existing highway, railway, aircraft, shipping after it consummation which will lead to a situation capacity.The new high-speed railway is mainly to carry passenger, so it will not speed up the turnover rate between cargos and the capital and will not decrease the costs of the whole social transportation.To build such a large network of high-speed rail will need a large amount of money, the government must increase the taxes of people and enterprise to raise the capital.If this financial investment used in health care, social security, education, tec

第三篇：英文翻译

Overview of the Global System for Mobile Communications 1 History of GSM During the early 1980s, analog cellular telephone systems were experiencing rapid growth in Europe, particularly in Scandinavia and the United Kingdom, but also in France and Germany.Each country developed its own system, which was incompatible with everyone else’s in equipment and operation.This was an

undesirable situation, because not only was the mobile equipment limited to operation within national boundaries, which in a unified Europe were increasingly unimportant, but there was also a very limited market for each type of equipment, so economies of scale and the subsequent savings could not be realized.The Europeans realized this early on, and in 1982 the Conference of European s Posts and Telegraphs(CEPT)formed a study group called the Group Special Mobile(GSM)to study and develop a pan-European public land mobile system.The proposed system has to meet certain criteria: ·Good subjective speech quality ·Low terminal and service cost ·Support for international roaming ·Ability to support handheld terminals ·Support for range of new services and facilities ·Spectral efficiency ·ISDN compatibility In 1989, GSM responsibility was transferred to the European Telecommunication Standards Institute(ETSI), and phase I of the GSM specifications were published in 1990.Commercial service was started in mid-1991, and by 1993 there were 36 GSM networks in 22 countries.Although standardized in Europe, GSM is not only a European standard.Over 200 GSM networks are operational in 110 countries around the world.In the beginning of 1994, there were 1.3 million subscribers worldwide, which had grown to more than 55 million by October 1997.With North America making a delayed entry into the GSM field with a derivative of GSM called PCS1900, GSM systems exist on every continent, and the acronym GSM now aptly stands for Global System for Mobile communications.The developers of GSM chose an unproven(at the time)digital system, as opposed to the then-standard analog cellular systems like AMPS in the United States and TACS in the United Kingdom.They had faith that advancements in compression algorithms and digital signal processors would allow the fulfillment of the original criteria and the continual improvement of the system in terms of quality and cost.The over 8,000 pages of GSM recommendations try to allow flexibility and competitive innovation among suppliers, but provide enough standardization to guarantee proper interworking between the components of the system.This done by providing functional and interface descriptions for each of the functional entities defined in the system.2 General Concepts 2.1 Analog Versus Digital Telephony Systems First-generation systems were analog.During the early 1980s these underwent rapid development in Europe.Although the NMT system was used by all the Nordic countries, and the TACS system in the United Kingdom and Italy, there was a variety of systems and no compatibility among them.Compared with these systems, the main advantages offered by GSM, which is the most important of the second-generation digital systems, are: ·Standardization;·Capacity;·Quality;·Security.Standardization guarantees compatibility among systems of different countries, allowing subscribers to use their own terminals in those countries that have adopted the digital standard.The lack of standardization in the first-generation system limited service to within the borders of a country.Mobility is improved, since roaming is no longer limited to areas covered by a certain system.Calls can be charged and handled using the same personal number even when the subscriber moves from one country to another.Standardization also allows the operator to buy entities of the network from different vendors, since the functional elements of the network and the interfaces between these elements are standardized.This means that a mobile phone from any manufacturer is able to communicate with any network, even if this network is built with entities from different vendors.This leads to a large economy of scale and results in cost reduction for both the operator and the subscriber.Furthermore, the phone cost is also reduced, because GSM is an international standard, produced quantities are greater and the level of competition is high.With respect to capacity, the use of the radio resource is much more efficient in a digital system such as GSM than in an analog system.This means that more users can be allocated in the same frequency bandwidth.This is possible with the use of advanced digital techniques, such as voice compression algorithms, channel coding, and multiple access techniques.Note that capacity gains are also achieved with radio frequency reuse, which had also used in analog systems.Frequency reuse means that a given carrier can be employed in different areas.The quality in digital transmission systems is better, thanks to the channel coding schemes that increase the robustness in the face of noise and disturbances such as interference caused by other users or other systems.The quality improvement is also due to the improved control of the radio link, and adaptations to propagation conditions, with advanced techniques such as power control or frequency hopping.This will be explained in greater detail in the next section.In terms of security, powerful authentication and encryption techniques for voice and data communications are enabled with GSM, which guarantees protected access to the network, and confidentiality.2.2 Cellular Telephony In mobile radio systems, one of the most important factors is the frequency spectrum.In order to make the best use of the bandwidth, the system is designed by means of the division of the service area into neighboring zones, or cells, which in theory have a hexagonal shape.Each cell has a Base Transceiver Station(BTS), which to avoid interference operates on a set of radio channels different from those of the adjacent cells.This division allows for the use of the same frequencies in nonadjacent cells.A group of cells that as a whole use the entire radio spectrum available to the operator is referred to as a cluster.The shape of a cell is irregular, depending on the availability of a spot for the BTS, the geography of the terrain, the propagation of the radio signal in the presence of obstacles, and so on.In dense urban areas, for instance, where the mobile telephony traffic is important, the diameter of the cells is often reduced in order to increase capacity.This is allowed since the same frequency channels are used in a smaller area.On the other hand, reducing the cell diameter leads to a decrease in the distance necessary to reuse the frequencies(that is, the distance between two co-channel cells), increasing co-channel interference.In order to minimize the level of interference, several techniques are used on the radio interface.A basic example of cluster organization is shown in Figure 1.In this example, we see a reuse attern for seven different frequencies, f1 to f7.These frequencies correspond to the beacon carrier of each cell, on which signaling information about the cell is broadcast(see Section 2.7).It can be seen from this figure that a given carrier can be reused in two separate geographical areas, as long as these areas are far enough from each other to reduce the effect of interference.With this technique of dividing the area in cells and clusters, the operator can increase the area it is able to cover with a limited frequency bandwidth.Figure 1 Example of a Cell Planning

在80 年代初期期间，模式手机系统在欧洲体验迅速增长，特别在斯堪的那

维亚和英国，以及法国和德国。每个国家开发了它自己的系统，在设备和操作 上是互不相容的。这是一个不受欢迎的情况，因为不仅移动通信设备被限制在国 界之内，这在统一的欧洲是越来越不重要的，而且每种类型的设备都只有一个非 常有限的市场，因此经济尺度及随后的储蓄不可能体会。

欧洲人早就意识到了这点，并且在1982 年欧洲邮电管理联合会(CEPT)上形 成了移动通信特别研究组(GSM)来研发一个能在全欧洲大陆通用的移动通信系 统。提出的系统必须符合以下标准： 〃通话质量好

〃终端及服务费用低 〃支持国际漫游

〃能够支持可随身携带的终端 〃支持一系列新的服务和设备 〃效率高

〃与ISDN 兼容

1989 年，GSM 的责任转移了到欧洲电信标准学院(ETSI)，并且GSM 规格的

第一阶段也在1990 年出版了。商业服务在1991 年中期开始了，截至1993 年有 36 个GSM 网络在22 个国家诞生了。GSM 不仅仅是欧洲标准，尽管它是在欧洲 规范化的。现已有200 多个GSM 网络在全球110 个国家和地区运行。1994 年初 期全球有1,300,000 用户，截至1997 年10 月已突破55,000,000 用户。随着美国

后来在GSM 领域制造了一个词条PCS1900 作为GSM 的拓展,GSM 系统已发展至 各大洲,并且缩写词GSM 现在已可以代表移动通信的全局系统。

GSM 开发商选择了一个当时未经证明的数字系统，与后来的标准模式蜂窝系 统相对，就象美国叫AMPS，而英国叫TACS 一样。他们坚信能够推进压缩算法 和数字信号处理器使其能够根据质量和费用将原始标准和系统连续改善。GSM 推荐8,000 页设法使得在与供应商竞争之中体现灵活性和创新，但提供 足够的标准来保证在系统的组分之间适当配合工作。完成提供功能和接口描述的 功能个体在系统中都有定义。

第一代系统是模拟的。上个世纪80 年代初期在欧洲迅速发展。虽然所有北 欧国家使用TACS 系统，英国和意大利使用NMT 系统，它们之间还有各式各样 的系统不兼容。和这些系统相比，GSM 提供的更重要的第二代数字系统主要优势 体现在： 〃标准化； 〃容量； 〃质量； 〃安全。

标准化保证了不同国家系统之间的兼容性，允许采取了数字化标准的国家的 订户使用他们自己的终端。在第一代系统中缺乏标准化的有限服务为在国家的边 界之内。流动性被改进，漫游不再被限制到某一系统包括的面积之内。既使当用 户从一个国家移动到另一个国家，电话也可以使用同一个个人号码。因为网络的功能元件和这些元素之间的接口被规范化，操作员可以从不同的 供营商购买。这意味着所有制造商的移动电话能与任何网络沟通，即使这个网络 是由不同的供营商的功能元件建立的。这为操作员和订户带来费用成本的降低。此外，电话费用也降低了，因为GSM 是国际标准，生产数量大，竞争水平高。能力方面，数字系统如GSM 比模拟系统使用的无线资源更有效。这意味着 更多的用户可以使用同一频带。这就有可能利用先进的数字技术，如语音压缩算 法，信道编码和多址接入技术。请注意，无线电频率复用也取得了一定增益，这 也已用于模拟系统。频率复用意味着同一载波可以在不同的地区重复使用。由于这种信道编码方案，提高了可靠性及对噪音和其他用户或系统的干扰能 力，数字传输系统的质量更好了。质量改进的原因还在于改善了对无线连接的控 制，并适应传播条件下，使用先进的技术，如电源控制或跳频。质量改进的原因 还在于使用先进的技术如电源控制或跳频改善了无线连接的控制,，传播条件的适

应性等。这些将在下文中做更详尽的解释。

在安全方面，GSM 具有语音和数据通信的强大的认证和加密技术的功能，保 证了保护接入网络和保密性。

在移动通信系统中，一个最重要的因素就是频谱。为了最有效地利用带宽，系统设计的目的是通过基站的服务区到周边小区，理论上是一个正六边形。每个 小区有一个收发基站（BTS），其中，以避免相邻小区的不同无线信道在运行时 产生相互干扰。这样可以在不相邻的小区使用同一载频。一组小区，作为一个整 体，给运营商提供整个无线电频谱是指一个区群。小区的形状是不规则的，这取 决于是否有现成的基站，地理地形，无线电信号传播中存在的障碍，等等。例如，在人口密集的城市地区，移动电话的通行非常重要，小区的直径往往 会减小，以提高其通行能力。

这是允许的，因为同一频道只在一个较小的地区内使用。另一方面，小区直 径的减小导致使用同一频率的小区间的距离（即两个公共通道小区间的距离）缩 小了，增强了各频道之间的相互干扰。为了尽量提高抗干扰的能力，无线接口使 用了一系列技术。

一个基本的区群组织的结构如图1 所示。在这个例子中，我们看到了一个复 用模式的7 个不同的频率，f1 至f7。这些频率对应于每个小区的信标载波，整个

小区的信号信息就靠它们被传播出去（见第2.7 节）。从图中可以看出，某一载 波可在两个不同的地理区域重复使用，只要这两个地区离的足够远，相互之间的 干扰足够小。这一技术把地区分成小区和区群，经营者可以利用有限的带宽增加 覆盖区域的面积。

第四篇：英文翻译

School Profile

Jin Yuan Primary School was founded in 1966，and now it has 40 years‟ history.Thepredecessor of the school is ShiMian kuang Children Shool.In May 1993 ,It was placed under the Dalian Development Zone.In 2002, the new building was reconstruction in the school site.Now it occupies a total area of 18500 square meters, with a total construction area of 9020 square meters, it has got 30 class and 1478 students.Our school always adhere to the school mission-“To lay the foundation for the development of student life” and school

philosophy “To train the younger generation for adapting to the new society”.with “implementing quality education, making our school into modernization, distinctive characteristics, high-grade The 'people satisfaction' schools ”for the school mission and goals.Focusing on behavior, raising habits, pursuingdevelopment, hing research,benefit, the high quality;grasping

characteristics, treeing famous“ as the school ideas.”Innovation in operating a school, Distinctive Features,“ as the school way.Our school has been named the standardization of school facilities,education and management of Dalian advanced group, Green School of Dalian , big break in Dalianadvanced unit for physical education curriculum standard education health system,development zone course reform summary advanced unit, the characteristics of the development of school-based curriculum development awards such as prizes, Excellence Award and many other honors.In addition, teaching and research training center was also named the Development of information technology, sports, music, experimental point of school mental health disciplines.School emphasis on ”Science Education“, it has been named the Science and technology activities advanced units;land-sea model training base in Liaoning Province;Dalian Science and Technology Advanced Unit;advanced science and technology activities in Dalian youth units;The intelligent robot teaching activities carried out to further broaden the field of science teaching in recent years, we got soccer robot competition and the Youth Science and Technology Invention Contest winners many times in national, provincial and municipal.Our school was known by scientific and technological innovations, it has become a golden source of education and school characteristics of primary brand, and its fruitful results of educating people to win recognition of the higher education sector and social praise.Our school actively promoting international exchanges and cooperation.Based on the national culture, the students involved in multicultural perspective, let the student to have the ability to

communicate with different culture and cultural understanding

ability, feeling the other civilizations, inheriting Chinese culture, and for students build facing the world, developing yourself and

development of China's platform.At present,we have established the friendly and cooperative relations with Singapore, Britain and other countries of the schools.Our school is committed to the construction of educational information, establishing the educational information to promote the development strategy of modernization of school education.We was honored with the first model school education information by Dalian Municipal Bureau of Education.Physical education in our schoolis also flourished, we always adhere to the ”Sunshine Sports“ project.To ensure that every student at least one hour of exercise a day, each have a favorite sport, the school was named the physical education curriculum standards of Dalian advanced unit, DalianBig calisthenics demonstration school, Dalian”campus football

project“ Development of school.In recent years,school „s sports teams in all kinds of various game had good performance , and it becomes the school‟sbeautifulcard.Standing at a new starting point, facing the new century, we will try to”build multicultural education, reveal personality, improve

the educational grade, promote the connotation development" as our target, makes determined efforts, scientific planning, and strive to improve the level and constantly expand its reputation, trying to be the children paradise of JinYuan Primary School.

第五篇：英文翻译

whether the university student should pay more atteion on studying or not ?the answer issure.First of all,during these time,we can touch more things,whichwehave not ever meet before and make a graetinflunce on our future life,If we don't handle it well,maybe we will lose a lot of thingswe adapt to sociaty more easily and more diffcult.we have time to play, but when you are playing and relaxing, dont forget the things you must do at school.school life is on of the best sections of your life.you need school life and time to learn and do things.