桥梁专业毕设文献翻译

毕业设计(文献翻译)

译文及原文复印件

学生姓名：左烨学号： 1804070233 所在学院：交通学院

专业：交通工程

文献题目： Bridges

桥梁类型

指导教师：罗韧

南京工业大学土木工程学院交通工程系

二O一一年三月

桥梁类型

梁桥

梁桥也许是最普遍也是最基本的桥梁结构形式。一根木头跨越小河是典型梁桥的一种最简单的实例。在现代的钢梁桥结构形式中，最常见的两种型式是I 型梁桥和箱梁。

如果我们考察I型梁的横截面我们马上就能理解为什么它被冠以如此的名字（见插图1）。梁的横断面采用了英文字母I大写的形状。中间的垂直板被称为肋板，而顶部和底部的平面板指的就是凸缘。要解释I型梁为什么是一种有效的截面型式是一项长期而艰巨的任务，因此在本篇文章中我们就不做解释了。箱梁得名如同于I型梁一样，很明显，它的截面形状类似于一个箱子。典型的箱梁截面型式有两个肋板和两个凸缘（见插图2）。

但是在某些情况下，两个以上的肋板就会形成存在剪力滞现象的多室箱梁。

其他梁桥的例子包括π型梁——因其截面类似于数学符号π而得名，还有T 型梁。因为绝大部分现今建造的梁桥都属于箱梁或是I型梁，所以我们会跳过这些少见的截面类型。

现在我们了解了I型梁和箱梁之间的外形差异，让我们来看看这两种截面型式的优缺点。I型梁截面设计和建造简单，在大部分情况下，使用效果也很好。但是，如果梁桥有任何形式的弯曲，梁就会受扭，也就是众所周知的扭矩。对比于I型梁，在箱梁中添加的第二个肋板增加了稳定性，也就增加了箱梁的抗扭性能。这就使得箱梁截面成为存在显著曲线梁桥的理想选择。

箱梁结构更稳定可以跨越更长的距离且经常用于大跨径桥梁，而使用I型梁就不会有足够的强度和稳定性。然而，设计构造箱梁桥相比于I型梁更为困难。例如，为了焊接箱型梁内的接缝，人工或是机械就必须能够控制箱梁产生的剪力滞。

桁架桥

桁架是一种简单的类似于骨骼的结构。在结构力学中，简单桁架的单个组成部分只受到拉力和压缩力，而不存在弯曲力。

因此,在大多数情况下,所有梁桁架桥是直的。桁架梁是由很多小桁架组成，

支撑大量的重量，跨越较大的距离。在大多数情况下,设计、制造和安装桁架是相对简单的。然而，一旦组装的桁架占用较大的空间，以复杂的结构形成，就会分散司机的注意力。

像梁桥一样，既有简单的桁架桥，又有连续桁架桥。桁架桥的各个部件体积小，使其成为在大型部件或部分部件不能装运或者大型起重机械和重型设备不能使用的地方处理想的桥梁型式。由于桁架是一个空洞的骨架结构，道路可能越过（见插图2）甚至通过（见插图1），同时考虑到桥下的清场，这是其他桥型不能比的。

桁架也按基本设计使用来分类。最具代表性的包括华伦桁架，普拉特桁架以及豪威桁架。华伦桁架也许是包括简单或是连续桁架中最常见的型式。对于跨度较小的，无垂直桁架可以给结构一个简单的外观（见插图1）。对于跨度较大的桁架桥，垂直桁架可以提供额外的力（见插图2）。华伦结构跨度通常为50~100米。

普拉特桁架因其对角线桁架组成除了两边均向跨度中心倾斜而得名。除了靠近中心的对角线桁架，其他所有的桁架只有在垂直短桁架受压力时受到斜拉力。这就使得可以用较为稀薄的桁架构成使得设计更为经济。

豪威桁架（见插图4）是普拉特桁架相反的结构。对角线桁架朝向相反方向并承担压力。这对于钢桥来说是非常不经济的，因此它的使用也是很少见的。刚架桥

刚构桥梁有时也被称为框架结构的桥梁。在标准的梁桥中，主梁和桥墩是分开的结构。然而刚构桥中主梁和桥墩是一个整体。

刚构桥的横截面通常是I型或是箱型。连续刚构桥的设计计算比简支梁桥复杂。桥墩和主梁的连接处制作困难，需要计算准确且注重细节。

尽管有许多可能的理论形状，但是近些年来使用的结构形式只有π型，斜腿形和V字型框架。

斜腿刚构桥特别适合于跨越河流山谷，因为倾斜一定角度的桥墩可以有效的跨越障碍而不需在河流中央修建基础或在山谷中修建桥墩（见插图1）。

V型刚构桥可以有效地利用基础。每个V字型墩提供两个支撑梁的力，同时减少基础的数量，从而使得外形更加简单。（见插图3）

π型刚构结构通常用于内城高速公路的桥墩或是支撑。该框架支撑起高出的公路，同时允许车辆从桥下直接通过。（见插图2）

拱桥

在梁桥之后，拱桥是第二古老的桥式和经典结构。不像简支梁桥，拱桥非常适合用石材建造。许多古老知名的拱桥时至今日仍然伫立着。穿越山谷与河流拱桥是个很好的选择，因为拱桥在中间部分不需要桥墩支撑。拱桥可以成为更美桥型之一。

拱桥使用曲拱结构，提供一个高抗弯力。不像梁桥和桁架桥，拱桥的两端固定在同一水平方向上（即不允许水平方向运动存在于轴之中）。因此当负载在桥上（如一辆车通过时）水平力就会在拱的轴承中产生。这些水平力对于拱桥来说是独特的，因此拱桥只能应用于地面基础牢固稳定的地方。

就像桁架桥一样，道路可能越过（见插图1）或者通过拱（见插图4）或者在某种情况下，两者都有（见插图3）。结构上拱桥有四种基本结构形式：无铰拱，双铰拱，三铰拱和系杆拱桥。

无铰拱（见插图1）没有铰并且不允许基础的转动。因此基础会承受大量的荷载（水平，垂直，弯曲力），因此无铰拱只能在地面基础十分稳定的情况下修建。然而，无铰拱是一种非常僵硬的结构比其他拱产生的挠度也就相对少了。

两铰拱（见插图2）使用了允许转动的铰接轴承。在轴承中只产生水平和垂直力。这或许是最常用的钢拱的更改，通常也是一个经济的设计方式。

三铰拱（见插图3）增加了一个铰链在拱的顶部。三铰拱因基础运动（地震，下沉等）受到的影响较小。然而，三铰拱会遭受等多的挠度影响，铰链很复杂，难以制作。因此三铰拱很少使用。

系杆拱桥（见插图4）是一种组合式拱桥，允许在地面不够稳固以抵抗水平力的变化的情况下建造。连接拱的两端和本身而不是依赖基础来承受水平力，因此称之为系杆拱桥。

斜拉桥

一座典型的斜拉桥（见插图1和2）是与一个或多个塔柱连续梁跨度中间桥墩的架设。缆绳从这些塔柱上拉下（通常向两边）来支撑主梁。

钢缆绳非常强韧有弹性。钢缆绳非常经济，且可以形成细长结构但仍然能跨

越较远距离。尽管少数的缆绳强度就足以支撑整个桥，他们的弹性使得缆绳很难承受我们很难考虑到得力：风力。

对于跨度较大的斜拉桥，必须做出仔细研究来确保缆绳和桥梁在风力作用下的稳定情况。

桥的重量越轻，对于风力的抵抗能力越弱，但是对于抵抗地震却是有利的。但是，地震或是时间推移下地基的不均匀沉降会使斜拉桥产生破坏，因此必须认真规划基础。斜拉桥即现代又简洁的外观，使之成为有吸引力独特的地标。

缆绳的独特属性以及其作为一个整体结构，使得斜拉桥的设计十分复杂。较大跨度的斜拉桥，风力和温度的影响必须考虑，这个计算是非常复杂的，不得不借助计算机和计算机分析。斜拉桥桥索的制作也比较困难。桥索的布线和主塔的附件构造复杂，需要精密制造。

斜拉桥没有明显的分类。但是，它可以根据跨越数，塔柱数，主梁类型和缆绳数量区分。塔柱的数量和类型有很多变化，缆绳的数目和排列也有变化。典型的主塔形式有：单柱、双柱、门形或是A型（见插图2和3）。

桥索的排列也不尽相同。典型的型式有单面、扇形、竖琴型、星型（见插图4）。在某些情况下，桥索只有在塔柱的一侧安装在梁上，另一侧被锚固在基础上或用以其他力来平衡。

悬索桥

现如今使用的所有桥型中，悬索桥是跨越距离最长的桥型。乍一看,这和悬浮的斜拉桥可能看起来很相似,但他们有很大的不同。虽然大跨度悬索桥现如今技术领先,但他们其实是一种很古老的形式的桥。一些最原始的悬索桥的例子是使用藤蔓和绳子作为缆索。

金属的发展带来了铁棍和锁链的使用。但是知道钢丝索的引进才使得跨越500米以上成为现实。今天明石海峡大桥拥有世界最长的1991米的跨度。

典型的悬索桥是与一个或多个桥塔通过缆绳与主梁在桥墩中央相连。主梁本身在较短的跨度下是桁架或是箱梁，板梁并不少见。桥的两端通过放置大型锚固设备或是重物用以固定缆绳。

主缆延伸从一个锚锭越过塔顶连接到另一个锚锭处。这种跨越结构的缆绳称之为马鞍（检查图2）。马鞍型允许缆绳从一边到另一边顺利地传递荷载。

从主缆悬挂下来的像挂钩一样的小缆绳悬挂下来连接在主梁上。有些悬索桥不适用锚锭，缆绳直接连接主梁的两端。依靠这些自锚悬索桥跨度的重量,以平衡中心跨度和锚定缆绳。

因此，不同于普通桥梁依靠墩台承重，悬索桥主梁或是桥面板实际上是悬挂在主索上。桥的大部分重量和车辆荷载都被缆索承担。反过来，缆绳由主塔支撑，因此主塔就必须支撑大量的重量。

正如以上解释的斜拉大桥钢缆索强度极强,然而灵活。就像一个很强韧的绳子,那将是很好的为悬挂或拉一些事的选择,但是试图推动物体是没有用的。大跨度悬索桥尽管在普通交通荷载下很强韧，极易受到风荷载的作用。必须采取特殊的措施以确保大桥在强风下不晃动或是振动。

最著名的空气动力不稳定的大桥的例子是美国华盛顿州的塔科玛湾海峡大桥。这篇英国布里斯托尔大学对于塔科玛湾海峡大桥灾难的优秀的网页照片和短片会解释为什么空气动力稳定性如此重要。

Bridges

Girder Bridge

A girder bridge is perhaps the most common and most basic bridge. A log across a creek is an example of a girder bridge in its simplest form. In modern steel girder bridges, the two most common girders are I-beam girders and

box-girders.

If we look at the cross section of an I-beam girder we can

immediately understand why it is called an Ibeam

(illustration #1.) The cross section

of the girder takes the shape of

the capital letter I. The vertical

plate in the middle is known as the web, and the top

and bottom plates are referred to as flanges. To

explain why the I shape is an efficient shape for a

girder is a long and difficult task so we won't attempt

that here.

A box girder is much the same

as an I-beam girder except that, obviously, it takes the

shape of a box. The typical box girder has two webs

and two flanges (illustration #2.)

However, in some cases there are more than two webs, creating a multiple chamber box girder.

Other examples of simple girders include pi girders, named for their likeness to the mathematical symbol for pi, and T shaped girders. Since the majority of girder bridges these days are built with box or I-beam girders we will skip the specifics of these rarer cases.

Now that we know the basic physical differences between box girders and

I-beam girders, let's look at the advantages and disadvantages of each. An

I-beam is very simple to design and build and works very well in most cases. However, if the bridge contains any curves, the beams become subject to twisting forces, also known as torque. The added second web in a box girder adds stability and increases resistance to twisting forces. This makes the box girder the ideal choice for bridges with any significant curve in them.

Box girders, being more stable are also able to span greater distances and are often used for longer spans, where I-beams would not be sufficiently strong or stable. However, the design and fabrication of box girders is more difficult than that of I beams. For example, in order to weld the inside seams of a box girder, a human or welding robot must be able to operate inside the box girder. Truss

The truss is a simple skeletal structure. In design theory, the individual members of a simple truss are only subject to tension and compression forces

and not bending forces.

Thus, for the most part, all beams in a truss bridge are straight. Trusses are comprised of many small beams that together can

support a large amount of weight and span great

distances. In most cases the design, fabrication, and

erection of trusses is relatively simple. However, once

assembled trusses take up a greater amount of space

and, in more complex structures, can serve as a

distraction to drivers.

Like the girder

bridges, there

are both simple

and continuous trusses. The small

size of individual parts of a truss make it the ideal bridge for places where large parts or sections cannot be shipped or where large cranes and heavy equipment cannot be used during erection. Because the truss is a hollow skeletal structure, the roadway may pass over (illustration #2) or even through (illustration #1) the structure allowing for clearance below the bridge often not possible with other bridge types.

Trusses are also classified by the basic design

used. The most representative trusses are the

Warren truss, the Pratt truss, and the Howe

truss. The Warren truss is perhaps the most

common truss for both simple and continuous trusses. For smaller spans, no vertical members are used lending the structure a simple look (illustration #1.) For longer spans vertical members are added providing extra strength (illustration #2.) Warren trusses are typically used in spans of between

50-100m.

The Pratt truss (illustration #3) is identified by its

diagonal members which, except for the very end

ones, all slant down and in toward the center of

the span. Except for those diagonal members near the center, all the diagonal members are subject to tension forces only while the shorter vertical members handle the compressive forces. This allows for thinner diagonal members resulting in a more economic design.

The Howe truss (illustration #4) is the opposite of

the Pratt truss. The diagonal members face in the

opposite direction and handle compressive forces.

This makes it very uneconomic design for steel bridges and its use is rarely seen.

Rigid Frame

Rigid frame bridges are sometimes also known as Rahmen bridges. In a standard girder bridge, the girder and the piers are separate structures. However, a rigid frame bridge is one in which the piers and girder are one solid structure.

The cross sections of the beams in a rigid frame bridge are usually I shaped or box shaped. Design calculations for rigid frame bridges are more difficult than those of simple girder bridges. The junction of the pier and the girder can be difficult to fabricate and requires accuracy and attention to detail.

Though there are many possible shapes, the styles used almost exclusively these days are the pi-shaped frame, the batter post frame, and the V shaped frame.

The batter post rigid frame bridge is

particularly well suited for river and valley

crossings because piers tilted at an

angle can straddle the crossing more effectively without requiring the construction of foundations in the middle of the river or piers in deep parts of a valley (illustration #1).

V shaped frames make effective use of foundations. Each V-shaped pier provides two supports to the girder, reducing

the number of foundations and creating a

less cluttered profile (illustration #3.)

Pi shaped rigid frame structures are used

frequently as the piers and supports for inner city

highways. The frame supports the raised highway and

at the same time allows traffic to run directly under the

bridge (illustration #2.)

Arch

After girders, arches are the second oldest bridge type and a classic structure. Unlike simple girder bridges, arches are well suited to the use of stone. Many ancient and well know examples of stone arches still stand to this day. Arches are good choices for crossing valleys and rivers since the arch doesn't require piers in the center. Arches can be one of the more beautiful bridge types. Arches use a curved structure which provides a high resistance to bending

forces. Unlike girder and truss bridges, both ends of an

arch are fixed in the horizontal direction (i.e. no horizontal

movement is allowed in the bearing). Thus when a load is

placed on the bridge (e.g. a car passes over it) horizontal

forces occur in the bearings of the arch. These horizontal

forces are unique to the arch and as a result arches can

only be used where the ground or foundation is solid and

stable

Like the truss, the roadway may pass over (illustration #1) or through an arch (illustration #4) or in some cases both (illustration #3.) Structurally there are four basic arch types: hinge-less, two-hinged, three hinged and tied arches.

The hinge-less arch (illustration #1)

uses no hinges and allows no rotation

at the foundations. As a result a great

deal of force is generated at the

foundation (horizontal, vertical, and bending forces) and the hinge-less arch can only be built where the ground is very stable. However, the hinge-less arch is a very stiff structure and suffers less deflection than other arches.

The two hinged arch (illustration #2) uses hinged bearings which allow rotation. The only forces generated at the

bearings are horizontal and vertical

forces. This is perhaps the most

commonly used variation for steel

arches and is generally a very

economical design.

The three-hinged arch (illustration #3)

adds an additional hinge at the top or

crown of the arch. The three-hinged

arch suffers very little if there is

movement in either foundation (due to earthquakes, sinking, etc.) However, the three-hinged arch experiences much more deflection and the hinges are complex and can be difficult to fabricate. The three-hinged arch is rarely used anymore.

The tied arch (illustration #4) is a variation on the arch which allows construction even if the ground is not solid

enough to deal with the horizontal forces.

Rather than relying on the foundation to

restrain the horizontal forces, the girder

itself "ties" both ends of the arch together, thus the name "tied arch."

Cable Stayed

A typical cable stayed bridge (illustration #1 & 2) is a continuous girder with one or more towers erected above piers in the middle of the span. From these towers, cables stretch down diagonally (usually to both sides) and support the girder.

Steel cables are extremely strong but very

flexible. Cables are very economical as

they allow a slender and lighter structure

which is still able to span great distances. Though only a few cables are strong enough to support the entire bridge, their flexibility makes them weak to a force we rarely consider: the wind.

For longer span cable-stayed bridges, careful studies must be made to guarantee the stability of the cables and the bridge in

the wind.

The lighter weight of the bridge, though a

disadvantage in a heavy wind, is an

advantage during an earthquake. However,

should uneven settling of the foundations

occur during an earthquake or over time,

the cable-stayed bridge can suffer

damage so care must be taken in planning

the foundations. The modern yet simple appearance of the

cable-stayed bridge makes it an attractive and distinct landmark.

The unique properties of cables, and the structure as a whole, make the design of the bridge a very complex task. For longer spans where winds and temperatures must be considered, the calculations are extremely complex and would be virtually impossible without the aid of computers and computer analysis. The fabrication of cable stay bridges is also relatively difficult. The cable routing and attachments for the girders and towers are complex structures requiring precision fabrication.

There are no distinct classifications for cable-stayed bridges. However, they can distinguished by the number

of spans, number of towers, girder

type, number of cables, etc. There

are many variations in the number

and type of towers, as well as the

number and arrangement of

cables. Typical towers used are

single, double, portal, or even A-shaped towers (illustration #2 & 3.)

Cable arrangements also vary greatly. Some typical

varieties are mono, harp, fan, and star arrangements

(illustration #4.) In some cases, only the cables on one

side of the tower are attached to the girder, the other

side being anchored to a foundation or other

counterweight.

Suspension

Of all the bridge types in use today, the suspension

bridge allows for the longest spans. At first glance the

suspension and cable-stayed bridges may look similar,

but they are quite different. Though suspension

bridges are leading long span technology today, they

are in fact a very old form of bridge. Some primitive

examples of suspension bridges use vines and ropes for cables.

The development of metals brought the use of linked iron bars and chains. But it was the introduction of steel wire ropes that allowed spans of over 500m to become a reality. Today the Akashi Kaikyo bridge boasts the world's longest center span of any bridge at 1,991 meters.

A typical suspension bridge (illustration #1) is a continuous girder with one or more towers erected above piers in the middle of the span. The girder itself it usually a truss or box girder though in shorter spans, plate girders are not uncommon. At both ends of the bridge large anchors or counter weights are placed to hold the ends of the cables.

The main cables are stretched from one anchor over the tops of the tower(s) and attached to the opposite anchor. The cables pass over a special structure known as a saddle (illustration #2.) The saddle allows the cables to slide as loads pull from one side or the other and to smoothly transfer the load from the cables to the tower.

From the main cables, smaller cables

known as hanger cables or hanger

ropes are hung down and attached to

the girder. Some suspension bridges

do not use anchors, but instead attach the main cables to the ends of the girder. These self-anchoring suspension bridges rely on the weight of the end spans to balance the center span and anchor the cable.

Thus, unlike normal bridges which rest on piers and abutments, the girder or roadway is actually hanging suspended from the main cables. The majority of the weight of the bridge and any vehicles on it are suspended

from the cables. In turn the cables are held up only by the

tower(s), there is an incredible amount of weight that the

towers must be able to support.

As explained in the cable stayed bridge section, steel cables

are extremely strong yet flexible. Like a very strong piece of

string, it is good for hanging or pulling something, but it is

useless for trying to push something. Long span suspension bridges, though strong under normal traffic loads, are vulnerable to the forces of winds. Special measures are taken to assure that the bridge does not vibrate or sway excessively under heavy winds.

The most famous example of an aerodynamically unstable bridge is the Tacoma Narrows Bridge in Washington state, USA. This page on the Tacoma Narrows Bridge Disaster at the University of Bristol has some excellent photos and short movies showing why aerodynamic stability is important.

毕设外文资料翻译.

理工学院 毕业设计外文资料翻译 专业：计算机科学与技术 姓名：马艳丽 学号： 12L0752218 外文出处：The Design and Implementation of 3D Electronic Map of Campus Based on WEBGIS 附件： 1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文 基于WebGIS的校园三维电子地图的设计与实现 一．导言 如今，数字化和信息化是当今时代的主题。随着信息革命和计算机科学的发展，计算机技术已经渗透到科学的各个领域，并引起了许多革命性的变化，在这些科目，古代制图学也不例外。随着技术和文化的不断进步，地图变化的形式和内容也随之更新。在计算机图形学中，地理信息系统（GIS）不断应用到Web，制作和演示的传统方式经历了巨大的变化，由于先进的信息技术的发展，地图的应用已经大大延长。在这些情况下，绘图将面临广阔的发展前景。电子地图是随之应运而生的产品之一。随着计算机技术，计算机图形学理论，遥感技术，航空摄影测量技术和其他相关技术的飞速发展。用户需要的三维可视化，动态的交互性和展示自己的各种地理相关的数据处理和分析，如此多的关注应支付的研究三维地图。东北石油大学及其周边地区的基础上本文设计并建立三维电子地图。 二．系统设计 基于WebGIS的校园三维电子地图系统的具有普通地图的一般特性。通过按键盘上的箭头键（上，下，左，右），可以使地图向相应的方向移动。通过拖动鼠标，可以查看感兴趣的任何一个地方。使用鼠标滚轮，可以控制地图的大小，根据用户的需求来查看不同缩放级别的地图。在地图的左下角会显示当前鼠标的坐标。在一个div层，我们描绘了一个新建筑物的热点，这层可以根据不同的地图图层的显示，它也可以自动调整。通过点击热点，它可以显示热点的具体信息。也可以输入到查询的信息，根据自己的需要，并得到一些相关的信息。此外，通过点击鼠标，人们可以选择检查的三维地图和卫星地图。 主要功能包括： ?用户信息管理：检查用户名和密码，根据权限设置级别的认证，允许不同权限的用户通过互联网登录系统。 ?位置信息查询：系统可以为用户提供模糊查询和快速定位。

桥梁工程毕业设计外文翻译箱梁

桥梁工程毕业设计外文翻译箱梁

西南交通大学本科毕业设计（论文） 外文资料翻译 年级: 学号: 姓名: 专业: 指导老师:

6 月

外文资料原文： 13 Box girders 13.1 General The box girder is the most ?exible bridge deck form. It can cover a range of spans from25 m up to the largest non-suspended concrete decks built, of the order of 300 m. Single box girders may also carry decks up to 30 m wide. For the longer span beams, beyond about 50 m, they are practically the only feasible deck section. For the shorter spans they are in competition with most of the other deck types discussed in this book. The advantages of the box form are principally its high structural ef?ciency (5.4), which minimises the prestress force required to resist a given bending moment, and its great torsional strength with the capacity this gives to re-centre eccentric live loads, minimising the prestress required to carry them.

论文外文文献翻译3000字左右

南京航空航天大学金城学院 毕业设计（论文）外文文献翻译 系部经济系 专业国际经济与贸易 学生姓名陈雅琼学号2011051115 指导教师邓晶职称副教授 2015年5月

Economic policy,tourism trade and productive diversification （Excerpt） Iza Lejárraga,Peter Walkenhorst The broad lesson that can be inferred from the analysis is that promoting tourism linkages with the productive capabilities of a host country is a multi-faceted approach influenced by a variety of country conditions.Among these,fixed or semi-fixed factors of production,such as land,labor,or capital,seem to have a relatively minor influence.Within the domain of natural endowments,only agricultural capital emerged as significant.This is a result that corresponds to expectations,given that foods and beverages are the primary source of demand in the tourism economy.Hence,investments in agricultural technology may foment linkages with the tourism market.It is also worth mentioning that for significant backward linkages to emerge with local agriculture,a larger scale of tourism may be important. According to the regression results,a strong tourism–agriculture nexus will not necessarily develop at a small scale of tourism demand. It appears that variables related to the entrepreneurial capital of the host economy are of notable explanatory significance.The human development index(HDI), which is used to measure a country's general level of development,is significantly and positively associated with tourism linkages.One plausible explanation for this is that international tourists,who often originate in high-income countries,may feel more comfortable and thus be inclined to consume more in a host country that has a life-style to which they can relate easily.Moreover,it is important to remember that the HDI also captures the relative achievements of countries in the level of health and education of the population.Therefore,a higher HDI reflects a healthier and more educated workforce,and thus,the quality of local entrepreneurship.Related to this point,it is important to underscore that the level of participation of women in the host economy also has a significantly positive effect on linkages.In sum, enhancing local entrepreneurial capital may expand the linkages between tourism and other sectors of the host country.

毕设外文文献翻译

xxxxxxxxx 毕业设计（论文）外文文献翻译 （本科学生用） 题目：Poduct Line Engineering: The State of the Practice 生产线工程：实践的形态 学生姓名：学号： 学部（系）: 专业年级: 指导教师：职称或学位： 2011年3月10日

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毕业设计外文翻译

毕业设计（论文） 外文翻译 题目西安市水源工程中的 水电站设计 专业水利水电工程 班级 学生 指导教师 2016年

研究钢弧形闸门的动态稳定性 牛志国 河海大学水利水电工程学院，中国南京，邮编210098 nzg_197901@https://www.sodocs.net/doc/6a18433259.html,，niuzhiguo@https://www.sodocs.net/doc/6a18433259.html, 李同春 河海大学水利水电工程学院，中国南京，邮编210098 ltchhu@https://www.sodocs.net/doc/6a18433259.html, 摘要 由于钢弧形闸门的结构特征和弹力，调查对参数共振的弧形闸门的臂一直是研究领域的热点话题弧形弧形闸门的动力稳定性。在这个论文中，简化空间框架作为分析模型，根据弹性体薄壁结构的扰动方程和梁单元模型和薄壁结构的梁单元模型，动态不稳定区域的弧形闸门可以通过有限元的方法，应用有限元的方法计算动态不稳定性的主要区域的弧形弧形闸门工作。此外，结合物理和数值模型，对识别新方法的参数共振钢弧形闸门提出了调查，本文不仅是重要的改进弧形闸门的参数振动的计算方法，但也为进一步研究弧形弧形闸门结构的动态稳定性打下了坚实的基础。 简介 低举升力，没有门槽，好流型，和操作方便等优点，使钢弧形闸门已经广泛应用于水工建筑物。弧形闸门的结构特点是液压完全作用于弧形闸门，通过门叶和主大梁，所以弧形闸门臂是主要的组件确保弧形闸门安全操作。如果周期性轴向载荷作用于手臂，手臂的不稳定是在一定条件下可能发生。调查指出:在弧形闸门的20次事故中，除了极特殊的破坏情况下，弧形闸门的破坏的原因是弧形闸门臂的不稳定;此外，明显的动态作用下发生破坏。例如:张山闸，位于中国的江苏省，包括36个弧形闸门。当一个弧形闸门打开放水时，门被破坏了，而其他弧形闸门则关闭，受到静态静水压力仍然是一样的，很明显，一个动态的加载是造成的弧形闸门破坏一个主要因素。因此弧形闸门臂的动态不稳定是造成弧形闸门(特别是低水头的弧形闸门)破坏的主要原是毫无疑问。

机械毕业设计英文外文翻译399驱动桥

附录A 英文文献 Drive Axle All vehicles have some type of drive axle/differential assembly incorporated into the driveline. Whether it is front, rear or four wheel drive, differentials are necessary for the smooth application of engine power to the road. Powerflow The drive axle must transmit power through a 90°angle. The flow of power in conventional front engine/rear wheel drive vehicles moves from the engine to the drive axle in approximately a straight line. However, at the drive axle, the power must be turned at right angles (from the line of the driveshaft) and directed to the drive wheels. This is accomplished by a pinion drive gear, which turns a circular ring gear. The ring gear is attached to a differential housing, containing a set of smaller gears that are splined to the inner end of each axle shaft. As the housing is rotated, the internal differential gears turn the axle shafts, which are also attached to the drive wheels. Rear-wheel drive Rear-wheel-drive vehicles are mostly trucks, very large sedans and many sports car and coupe models. The typical rear wheel drive vehicle uses a front mounted engine and transmission assemblies with a driveshaft coupling the transmission to the rear drive axle. Drive in through the layout of the bridge, the bridge drive shaft arranged vertically in the same vertical plane, and not the drive axle shaft, respectively, in their own sub-actuator with a direct connection, but the actuator is located at the front or the back of the adjacent shaft

毕业论文英文参考文献与译文

Inventory management Inventory Control On the so-called "inventory control", many people will interpret it as a "storage management", which is actually a big distortion. The traditional narrow view, mainly for warehouse inventory control of materials for inventory, data processing, storage, distribution, etc., through the implementation of anti-corrosion, temperature and humidity control means, to make the custody of the physical inventory to maintain optimum purposes. This is just a form of inventory control, or can be defined as the physical inventory control. How, then, from a broad perspective to understand inventory control? Inventory control should be related to the company's financial and operational objectives, in particular operating cash flow by optimizing the entire demand and supply chain management processes (DSCM), a reasonable set of ERP control strategy, and supported by appropriate information processing tools, tools to achieved in ensuring the timely delivery of the premise, as far as possible to reduce inventory levels, reducing inventory and obsolescence, the risk of devaluation. In this sense, the physical inventory control to achieve financial goals is just a means to control the entire inventory or just a necessary part; from the perspective of organizational functions, physical inventory control, warehouse management is mainly the responsibility of The broad inventory control is the demand and supply chain management, and the whole company's responsibility. Why until now many people's understanding of inventory control, limited physical inventory control? The following two reasons can not be ignored: First, our enterprises do not attach importance to inventory control. Especially those who benefit relatively good business, as long as there is money on the few people to consider the problem of inventory turnover. Inventory control is simply interpreted as warehouse management, unless the time to spend money, it may have been to see the inventory problem, and see the results are often very simple procurement to buy more, or did not do warehouse departments . Second, ERP misleading. Invoicing software is simple audacity to call it ERP, companies on their so-called ERP can reduce the number of inventory, inventory control, seems to rely on their small software can get. Even as SAP, BAAN ERP world, the field of

毕业设计外文翻译格式实例.

理工学院毕业设计(论文)外文资料翻译 专业：热能与动力工程 姓名：赵海潮 学号：09L0504133 外文出处：Applied Acoustics, 2010(71):701~707 附件： 1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文 基于一维CFD模型下汽车排气消声器的实验研究与预测Takeshi Yasuda, Chaoqun Wua, Noritoshi Nakagawa, Kazuteru Nagamura 摘要目前，利用实验和数值分析法对商用汽车消声器在宽开口喉部加速状态下的排气噪声进行了研究。在加热工况下发动机转速从1000转/分钟加速到6000转/分钟需要30秒。假定其排气消声器的瞬时声学特性符合一维计算流体力学模型。为了验证模拟仿真的结果，我们在符合日本工业标准（JIS D 1616）的消声室内测量了排气消声器的瞬态声学特性，结果发现在二阶发动机转速频率下仿真结果和实验结果非常吻合。但在发动机高阶转速下（从5000到6000转每分钟的四阶转速，从4200到6000转每分钟的六阶转速这样的高转速范围内），计算结果和实验结果出现了较大差异。根据结果分析，差异的产生是由于在模拟仿真中忽略了流动噪声的影响。为了满足市场需求，研究者在一维计算流体力学模型的基础上提出了一个具有可靠准确度的简化模型，相对标准化模型而言该模型能节省超过90％的执行时间。 关键字消声器排气噪声优化设计瞬态声学性能 1 引言 汽车排气消声器广泛用于减小汽车发动机及汽车其他主要部位产生的噪声。一般而言，消声器的设计应该满足以下两个条件：（1）能够衰减高频噪声，这是消声器的最基本要求。排气消声器应该有特定的消声频率范围，尤其是低频率范围，因为我们都知道大部分的噪声被限制在发动机的转动频率和它的前几阶范围内。（2）最小背压，背压代表施加在发动机排气消声器上额外的静压力。最小背压应该保持在最低限度内，因为大的背压会降低容积效率和提高耗油量。对消声器而言，这两个重要的设计要求往往是互相冲突的。对于给定的消声器，利用实验的方法，根据距离尾管500毫米且与尾管轴向成45°处声压等级相近的排气噪声来评估其噪声衰减性能，利用压力传感器可以很容易地检测背压。 近几十年来，在预测排气噪声方面广泛应用的方法有：传递矩阵法、有限元法、边界元法和计算流体力学法。其中最常用的方法是传递矩阵法（也叫四端网络法）。该方

毕设英文翻译英文版

72页 Machine Tools Objectived. Machine tools are the main engines of the manufacturing industry. This chapter covers a few of the details that are common to all classes of machine tools discussed in this book. After completing the chapter, the reader will be able to >understand the classification of the various machine tools used in manufacturing industries. >identify the differences between generating and forming of surfaces. > identify various methods used to generate different types of surfaces. >distinguish between the different accuracies and surface finishes that are achievable with different machine tools. >understand the different components of the machine tools and their functions. >learn about the different support structures used in the machine tools. >understand the various actuation systems that are useful to generate the required surfaces. >Learn the different types of guideways used in the machine tools. >understand the work holding requirements. 3.1 INTRODUCTION The earliest known machine tools are the Egyptian foot-operated lathes.

PLC毕业设计的外文文献(及翻译)

PLC technique discussion and future development Test Equipment-principles and Applications Princeton University .America Along with the development of the ages, the technique that is nowadays is also gradually perfect, the competition plays more strong; the operation that list depends the artificial has already can't satisfied with the current manufacturing industry foreground, also can't guarantee the request of the higher quantity and high new the image of the technique business enterprise. The people see in produce practice, automate brought the tremendous convenience and the product quantities for people up of assurance, also eased the personnel's labor strength, reduce the establishment on the personnel. The target control of the hard realization in many complicated production lines, whole and excellent turn, the best decision etc, well-trained operation work, technical personnel or expert, governor but can judge and operate easily, can acquire the satisfied result. The research target of the artificial intelligence makes use of the calculator exactly to carry out, imitate these intelligences behavior, moderating the work through person's brain and calculators, with the mode that person's machine combine, for resolve the very complicated problem to look for the best path. We come in sight of the control that links after the electric appliances in various situation, that is already the that time generation past, now of after use in the mold a perhaps simple equipments of grass-roots control that the electric appliances can do for the low level only; And the PLC emergence also became the epoch-making topic, adding the vivid software control through a very and stable hardware, making the automation head for the new high tide. The PLC biggest characteristics lie in: The electrical engineering teacher already no longer electric hardware up too many calculations of cost, as long as order the importation that the button switch or the importation of the sensors order to link the PLC up can solve problem, pass to output to order the conjunction

毕业设计外文翻译

毕业设计外文资料翻译 设计题目: 译文题目: 太阳能蒸笼 学生姓名： 学号： 专业班级： 指导教师： 正文：外文资料译文附件：外文资料原文

太阳能蒸笼 罗达.斯坦塔食品和营养学助理 许多不同的系统介绍了太阳能炊具。不同的设计有不同的优势。它也表明太阳能灶还处于初级阶段,将有希望有个美好的未来,不仅有助于解决气候变化问题,而且在做一件重要的事,服务许多人的生命。

大部份太阳能炊具有某种形式的反光罩的集中太阳的能量。太阳轮使用不反光但集中太阳能通过创造蒸汽从相对较大的收集器区域,并将其用于一个较小的烹饪区。随着太阳能轮使用蒸汽作为传热媒介,它是一种间接的烹饪系统。这允许一个分裂的烹饪系统,其热太阳能集热器可以放置在某个距离(如在屋顶上)除了烹饪的地方(例如在厨房里)。厨师正在不接触阳光的并且可以用蒸汽,无论高低都方便,可接受的区域。 这使它成为一个非常方便的炊具为大量的食物。使用简单叠加可以蒸煮几样菜，可以煮熟的同时进行。那热气腾腾的过程是非常相似与传统蒸煮过程，应该容易得到各种文化的认可。 太阳所产生的蒸汽也可以被用来热量大的罐炖肉或汤通过引导蒸汽直接进入了液体在它凝聚和释放的热凝。这就引起我做一个温柔的风潮的食品烤干。 在其设计技术,利用太阳船的有效性标准疏散管太阳能集热器可降低成本。 配料系统 可以看出从素描以上基本的想法是很简单的。太阳能收集器里装满了水。因为它具有极高的效率和良好的保温玻璃管的撤离开始沸腾的水会暴露在阳光下时。蒸汽会被引导到蒸笼以灵活的、蒸汽抗性软管。 连续系统

最后更复杂的,因为它必须确信,玻璃管永远不会变干的。一滴滴喂料系统集成式换热器提供了一条连续的淡水来代替水流失为蒸汽。这也防止了重建的盐和污染的太阳能集热器。因为这个系统包含了大量的沸腾的水在玻璃管,它具有使绝对肯定,没有压力,建立该体系。 成本 为了保持成本低，Sun2Steam正在出售一转换工具包可以很容易地安装在一个标准的低成本太阳能集热器。此套将直接来自澳大利亚,而太阳能收集器可直接来源于一个低成本的供应商。 一个太阳能集热器和20管直径和57mm 1.8米长，在中国是可以买到的大约200美元。转换组件包括500万绝缘软管取决于汇率蒸汽将大约200美元。成本增加25%,装船的税负导致的总费用为500美元左右的太阳能船没有安装费用和培训。 这使得轮船进入上部成本支架太阳能炊具。然而所有的材料都要持久和完整的炊具应该很容易超过了一生的10年。炉子可以很容易地帮助准备食物为10人。这使人均成本的太阳能减少至约五十美元。 也有一些额外的好处。太阳轮能生产大约5升的高质量的蒸馏水一天所产生的凝汽。一个可选的转换器将允许生产超过100升的安全、pasteurised饮水每天。报告描述太阳能蒸笼在这里可以找到: 大多数高海拔的烹饪和烘烤的指示不推荐补偿,直到你到达约6000英尺的海拔高度。居住在该地区,并且现在我住在怀俄明,是正确的,我们的高度范围你真正开始注重细微的差别,所以我已经学会补偿烤时和烹饪。 水沸腾时会出现在较低的温度在这里——这是由于减少了空气压力。你不会真正注意到什么大的差异在4000英尺,甚至在6000英尺,唯一的真正的区别是面带最微小的更久一点做饭,和糙米试你的耐心一点超过正常(以接近一个小时做饭,而不是通常的40分钟)。糖果还可以要求较长的沸腾时期达到各种球类或裂缝阶段。最引人注目的差异在这个高度是烤面包。蛋糕是一个倾向于看起来更温柔,更容易摔跤在中间。面包做一些有趣的事情。 蛋糕混合料通常会表明你应该添加额外的勺面粉加入混合,如果你是在高海拔超过5-6000呎。你可能需要补偿甚至更多,如果你是比那更高一些。

毕设外文翻译

英文翻译 题目: 通过分析变压器中溶解气体而进行故障诊断的专家系统 姓名: 宋日成 学院: 工学院 专业: 自动化 班级: 自动化112 班学号: 32211218 指导教师: 陆静职称: 讲师 2015年3月14日 南京农业大学教务处制

An Expert System for Transformer Fault Diagnosis Using Dissolved Gas Analysis W. S. Chan ·Y. L. Xu ·X. L. Ding ·W. J. Dai Received: 9 November 2005 / Accepted: 11 August 2006 / Published online: 7 September 2006? Springer-Verlag 2006 Abstract In order to automate the transformer fault diagnosis, improve the accuracy of judgment, the introduction of artificial intelligence expert system fault diagnosis. The system is based on fuzzy reasoning confidence by observing the information, the use of knowledge to reach a conclusion. Test proved this method reduces the randomness of judgment, improved diagnosis. Keywords:Expert System Transformer Troubleshooting 1 Introduction The power transformer is a major apparatus in a power system, and its correct functioning is vital to system operations. In order to minimize system outages,many devices have evolved to monitor the serviceability of power transformers. These devices, such as, Buchholz relays or differential relays, respond only to a severe power failure requiring immediate removal of the transformer from service, in which case, outages are inevitable. Thus, preventive techniques for early detection faults to avoid outages would be valuable. In this way, analysis of the mixture of the faulty gases dissolved in insulation oil of power transformer has received worldwide recognition as an effective method for the detection of incipient faults. Many researchers and electrical utilities have reported on their experience and developed interpretative criteria on the basis of DGA. However, criteria tend to vary from utility to utility. Each approach has limitations and none of them has a firm mathematical description. Therefore, transformer diagnosis is still in the heuristic stage. For this reason, knowledge-based programming is a suitable approach to implement in such a diagnostic problem. Based on the interpretation of DGA, a prototype of an expert system for diagnosis of suspected transformer faults and their maintenance procedures is proposed. The significant source in this knowledge base is the gas ratio method. Some limitations of this approach are overcome by incorporating the diagnostic procedure and the synthetic expertise method. Furthermore, data bases adopted from TPCS gas records of transformers are incorporated into the expert system to increase the practical performance. Uncertainty of diagnosis is managed by using fuzzy set concepts. This expert system is constructed with rule based knowledge representation, since it can be expressed by experts. The expert system building tool, Knowledge Engineering System (KES), is used in the development of the knowledge system