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大学专业英语杂志翻译(译文)

大学专业英语杂志翻译(译文)
大学专业英语杂志翻译(译文)

“科学指南”网站中国航空杂志266-271 20(2007) 艾斯维尔公司网站

基于PLC的张力控制系统的发展REN Sheng-le*, LU Hua, WANG Yong-zhang, FU Hong-ya

中国哈尔滨工业大学机械工程学系

接收于2006年5月22日;2006年11月22日接受

摘要:

在直接影响缠绕型产品质量好坏的复合材料成型工艺中,纤维缠绕张力是一种很重要的因素,张力控制是纤维缠绕的关键技术。本文介绍了用可编程逻辑控制器作为控制核心,交流(AC)伺服电机作为执行元件和radius-following设备功能模块(PLC)的闭环张力控制系统,实现实时半径补偿。这就分析了张力控制系统的结构,建立了数模。进而对卷曲半径的补偿技术进行分析。实验结果表明,该系统具备着非常高的控制精度和非常快反应速度。

关键词:

张力控制、可编程控制器、数控绕线机、交流伺服电机的数字

复合材料纤维缠绕的组件具有低重量,高强度,高耐腐蚀等优点,并已广泛运用在航空航天工业中。许多研究表明,不适当的或不稳定的张力会导致纤维缠绕强度成分20%-30%的损失。一个理想的张力控制系统应提供在缠绕过程稳定和张力可调节的环境中[1-3]。

到目前为止,绕线机、张力控制器经过三年的发展,即经历了机械张力控制器,张力控制器,电气和计算机张力控制器阶段[4-5]。随着电子技术的发展和高性能微处理器的出现,电脑张力控制器开始使用。微处理器成为控制系统的核心,从而减少了电子控制系统的电路,大大简化了系统,提高了可靠性,尽量应用先进的控制方法。因此,这种类型的控制器被广泛应用[6-7]。

在一些发达国家的不断改善中,张力控制技术日趋成熟和规范。然而,中国的纤维缠绕产业起步较晚,与西方国家相比仍然被甩在身后。

国产的机械张力应用设备大多响应速度慢、精度低,不能满足紧张的市场需求。因此,本文提出了一种基于PLC的张力控制系统。

1 系统设计

1.1系统的构造

一个缠绕张力控制系统一般包括三个主要部分,即退绕机、加工机和卷绕机,也可能会包含测量和控制部分,附加运输设备和压力传感器。在退绕机和卷绕机这两种类型中,可能一个为内部驱动,一个为外部驱动。外部驱动是指卷轴或皮带在卷绕的材料表面上运动时的驱动力,这种驱动力是由摩擦力产生的。内部驱动是指在卷轴中装一个驱动装置,在卷轴上的线速度和纤维缠绕张力是随缠绕物的半径的变化而变化的,导致所谓的“缠绕厚度”[8]。这种“缠绕厚度”现象让张力控制变得非常复杂,但由于内部驱动有很强适应性,内部驱动模式被广泛应用。

1.2 张力控制方案的设计

该系统采用了内部驱动和向外拖拉纤维的配置方案。因为交流数字伺服电机输出转矩与纤维张力和缠绕物半径成正比,所以为了恒定的纤维张力,输出转矩兼缠绕物半径应适当地减小。缠绕物半径的变化可以用半径跟随器来测量与取样,然后再通过数字模拟转换器发送到PLC。通过阅读张力的期望值,半径和张力可以用预调计算的算法来估计。发送控制转速和转矩的指令,再将这种指令数模转换成模拟电压信号输出来控制伺服驱动器。这种伺服驱动器以控制转速和输出转矩来控制纤维的张力。用脉冲编码器和霍尔元片来分别测量伺服电机的转速和转矩,再把它反馈给PLC,这样就一起构成了一个闭环系统。该系统的机制如图1所示:

系统的主要组成部分包括:

(1)松下可编程控制器(FP0 - C10RS),12位FP0 - A80和FP0 - A04V辅助转换模块。

(2)松下数字交流伺服驱动器和伺服电机。

(3)一个半径跟随器,包括一个半径跟随臂和一个旋转电位器。

2 数学模型

在纤维缠绕中,纤维张力的有效控制是很必要的。由于核心和卷绕的形态不断变化,纤维的线速度很难保持不变,而且这形态变化的原理也极其复杂。因此,线速度在张力上的影响,应考虑在被控对象的力学分析上。PLC与作为控制系统核心的功能模块和所需的张力可以从通过在PLC和上位机之间的串行通信的人机界面来设定。半径值,转矩反馈和速度反馈的输入,预设计算算法的运行和系统的输出都由PLC与功能模块来完成。

退绕时,动转矩平衡方程的表示,如下:

其中T是纱线张力,R(t)是实时滚动半径,M(t)为交流伺服电机的抗性时间,

是粘性摩擦力矩,ω(t)是滚动的角速度,是滚动和纱辊的转动惯量,

是干摩擦时间。

式(1)所示,滚动半径,抗性时间,退绕的角速度和滚动的转动惯量都是关于时间的功能,因此该系统是一个时间复杂多变的系统。

根据以下规则,和经典控制理论实现了转矩平衡公式的简化:

(1)干摩擦力矩和粘滞摩擦力矩很小,可能会被忽略。

(2)在张力中的影响可以被忽略,因为惯性的瞬时变化非常小。

(3)滚动半径被半径跟随器实时测量和反馈。

式(1)就简化成了:

因此,滚动直径和角速度的变化就成了纱线张力主要的影响因素。

3 滚动半径的补偿

滚动时半径的变化导致滚动时间的变化,即式(2)中TR(t)的变化。半径跟随臂的一端接触滚轴,另一端经过传送放大后连接到旋转电位器,从而把转轴半径的变化转变为电压的变化,如图2所示:

由于L>>AB,则有:

整理,得:

其中L为半径跟随臂的长度,是缠绕物的最大半径,为瞬时缠绕半径。假设传动比为,那么微传动角为:

对于电位器:

其中U是旋转电位器的输出电压,是旋转电位器电源电压,为旋转电位器总角度。整理,得:

4 系统的软件开发

软件开发充分利用了FP0-C10RS、I/ODA模块和PC电脑的软硬件的功能。AD或DA转换的精度取决于AD转换器和DA转换器的位数。FP0 - A80和FP0 - A04V都是12位,当输出和输入范围为(- 10V~+10 V)时,分辨率为1 / 4 000,而FP0为16位,所以该系统的控制精度可以放心。每个基本指令的运算速度为0.9微秒/步,因此500步的程序只需要0.5毫秒,而FP0 - A80和FP0 - A40V 的转换速度都是1毫秒/频,因此该系统的控制速度也可以放心。整个控制程序的前前后后都应用了PLC的梯形图。然而,参数输入不直观,也不是张力和滚动半径的实时显示。为了解决这个问题,对关于操作员能执行参数输入和实时张力、速率和滚动半径显示的界面主机的控制程序进行了开发。所有FPPLC的程序编制端口都支持OPEN MEWTOCOL PROTOCOL。上位机发送一个ASCLL字符串指令到PLC,PLC就自动返回基于这个指令的响应。

%:这是一个固定的字符,意味着下一个指令的开头。当PLC收到“%”时,先前所有未完成的文本字符串都被忽略。

#,$,!:说明哪些是指令(#)、反应($)或错误响应(!)。

该系统的输入是半径跟随装置的电压反馈,数字交流伺服电机的转矩反馈和速率反馈。系统的输出的是数字交流伺服电动机转矩和速度的电压。这个张力控制系统的软件控制的流程,如图3所示:

5仿真和实验结果

张力控制在实际缠绕情况中的实验研究是通过模拟实际工作环境去检验它的可行性和控制精度来实现的。当张力设置为10 N时,模拟和实验条件下的恒定张力曲线可以取成近似恒定张力,分别如图4和图5所示。为了了解当张力变化时交流伺服电机的工作状态,张力从5N变到10N时,在模拟和实验条件下的曲线变化如图6和图7所示,其中超调量和波动宁愿很小,也不让响应时间大于0.3秒。

图4 模拟中张力随时间的变化

图5 实验中张力随时间的变化

图6 模拟中张力随时间的变化(5N~10N)

图7 实验中张力随时间的变化(5N~10N)

5.1 静态误差率的分析

静态差异率是评估该系统的性能非常重要的指标。它可以表示为:

其中,是最大张力,是最小张力,Tm为平均紧张。

张力静态误差率的分析如表1所示:

从上面的分析看出,系统的静态误差小于4%,达到了所要求的性能指标。

5.2 波动率的分析

张力波动率是否符合要求是评估所设计的张力控制系统性能的关键指标。制定了初始化的纱线张力,计算补偿后,输出。然后,测试实际张力,并找出最大和最小的张力。计算波动率δ'的方程式如下:

张力波动率的分析如表2所示:

6 结论

模拟和实验的结果表明:用PLC作为核心,AC数字伺服电机作为执行元件和用半径跟随器完成半径补偿的系统是可行的。该系统的特点包括:(1)松下FP系列PLC和功能模块作为控制核心。体积小、高集成、高可靠、控制能力卓越和成本低廉让系统在高可靠和高精度方面变得紧凑和方便。

(2)纱线重取装置可以被忽略,因为伺服电机也可以执行同样的功能。

(3)模块化的软件设计易于构造的扩充和客户的二次开发。

(4)松下FPWIN_GR软件融洽的编程环境封装了在线编程的性能。可以在线改变参数,而且其控制的效果可以视为是瞬间完成的。

参考文献:

[1] Leng X W. 纤维缠绕原理。山东:山东科学技术出版社1990.【中国】

[2] Wang Q S. 基于PLC张力控制系统精度的基础和实验研究。博士论文,哈尔滨:哈尔滨工业大学2005.【中国】

[3] Wang C X, Wang Y Z, Lu H.使用磁粉离合器作为元件的张力控制系统。机械与电子1999;(3):5-7. 【中国】

[4] Lossie M, Brussel H V.纤维缠绕的设计原则。复合材料制造1994;5(1):5-13.

[5] Miller G A.纺织物缠绕张力的控制。机械电子学1995;5(2):117-131.

[6] Dudzinski M.理解内部驱动缠绕机第一部分。动力传输设计1995;37(4):27-31.

[7] Gerd V, Kurt H.张力控制的价值与方法。电气电子绝缘会议的章程1997 IEEE。NJ,USA:Piscata方式,1997;517-524.

[8] Johnayers缠绕控制的奥秘获取。动力传输设计1988;30(4):27-34.

传记:

REN Sheng-le出生于1979年。2000年哈尔滨工程大学学士,2002年哈尔滨工业大学硕士,2002年哈尔滨工业大学哲学博士候选人。现在,他的研究兴趣包括数控绕线机和张力控制系统。

E-mail: renshengle@https://www.sodocs.net/doc/4b3306984.html,

LU Hua生于1954年。哈尔滨工业大学硕士导师、高级工程师。他已经完成了超过18项科研项目,并且在近几年已经发表了超过20篇学术论文。现在,他的研究兴趣包括计算机控制NC技术。

E-mail: nc-mach@https://www.sodocs.net/doc/4b3306984.html,

WANG Yong-zhang生于1941年。哈尔滨工业大学教授,博士生导师。他完成了22个科研项目和5个科研专著,并且在近几年发表了超过70篇学术论文。现在,他的研究兴趣包括NC技术,计算机在机械制造上的应用和现代制造系统的设计、制造和控制。

E-mail: nc-mach@https://www.sodocs.net/doc/4b3306984.html,

FU Hong-ya生于1963年。哈尔滨工业大学教授,博士生导师。他完成了10多个科研项目,并且在近几年发表了超过30篇学术论文。现在,他的研究兴趣包括NC技术和理论研究及CAD / CAM应用。E-mail: nc-mach@https://www.sodocs.net/doc/4b3306984.html,

汽车专业英语翻译综合

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翻译期末作业

浅谈中国菜名的翻译 我国悠久的历史和广袤的国土孕育了中国独特的烹饪艺术和丰富的饮食文化。我们国家也以几千年的饮食文化文明于世。随着我国经济飞速发展,与国外交流日益增多,餐饮业也面临着走向世界的机遇和挑战。中国菜名是汉语语汇中承载中国文化最多的语汇之一, 不仅承载着几千年来的中国饮食文化, 还承载着大量的非饮食文化, 如神话、民俗、历史、文学、宗教信仰等等, 在菜名所传达的表层语义背后有着更为深厚复杂的多元文化元素。同时由于饮食与文化的密切联系,这些都大大增大了翻译的难度。 1.首先我们来看一下一些我们常见的错误翻译 长期以来,菜名的翻译没有统一的标准,加上译者水平有限和地域差异,并不了解菜式的内涵,致使很多菜名的翻译让人感到不知所云。比如口水鸡slobbering chicken、童子鸡chicken without sexual life、夫妻肺片the couple’s lung 等,这翻译让外国人看了都吓跑了,哪里还有食欲吃饭呢?再如东坡肉poet Dongpo’s braised pork,东坡肉是用蒸的方法做出来的,所以这里应该为Poet Dongpo’s steamed pork 而不是用braised;“鱼香肉丝”较常见的有两种译法,另外也有人译为shredded pork with garlic sauce,前者译法为直译,后者加了简单的解释,虽然看似简单易懂,很直观,但是译者没有弄清楚此菜的配料,川菜口味浓重,很多菜肴的配料都是少不了“川菜之魂”郫县豆瓣酱,鱼香肉丝正是用到此配料,是不用所谓的大蒜酱,所以后者翻译存在误的地方;水煮鱼,也是川菜中的代表作,又麻又辣,有译者翻译为tender stewed fish,这个译法不够全面,应该在后面加上in chili sauce;夫妻肺片译为pork lungs in chili sauce,这个译法的译者应该不明白此菜的来历和主料,夫妻肺片根本不是用猪肺做成的,而且和肺一点都不沾边,此菜的主料都是用牛内脏,所以这个译发讲不通。对于以上的翻译错误我们不能只是一笑而过,我们应该感受到菜名翻译的难度,从而思考怎样才能更好的翻译来达到最佳的效果。

英文报纸常用词

下午茶high tea 微博Microblog 裸婚naked wedding 亚健康sub-health 愤青young cynic 灵魂伴侣soul mate 小白脸toy boy 人肉搜索flesh search 公司政治company politics 剩女3S lady(single,seventies,stuck)/left girls 山寨copycat 异地恋long-distance relationship 钻石王老五diamond bachelor 时尚达人fashion icon 御宅otaku 上相的,上镜头的photogenic 脑残体leetspeak 学术界academic circle 哈证族certificate maniac 偶像派idol type 熟女cougar(源自电影Cougar Club) 挑食者picky-eater 伪球迷fake fans 紧身服straitjacket

团购group buying 家庭暴力family/domestic volience 炫富flaunt wealth 决堤breaching of the dike 上市list share 赌球soccer gambling 桑拿天sauna weather 自杀Dutch act 假发票fake invoice 二房东middleman landlord 入园难kindergarten crunch 生态补偿ecological compensation 金砖四国BRIC countries 笑料laughing stock 泰国香米Thai fragrant rice 学历造假fabricate academic credentials 泄洪release flood waters 狂热的gaga eg: I was gaga over his deep blue eyes when I first set eyes on him 暗淡前景bleak prospects 惊悚电影slasher flick 房奴车奴mortgage slave 上课开小差zone out 万事通know-it-all 毕业典礼commencement

汽车专业英语翻译

About car engine Of all automobile components,an automobile engie is the most complicated assembly with dominant effects on the function of an autombile.So, the engine is generally called the"heat"of an automobile. 在汽车的所有部件中,汽车发动机是最复杂的组件,其对整车性能有着决定性的作用。因而发动机往往被称作发动机的“心脏”。 There are actually various types of engines such as electric motors,stream engines,andinternal combustion engines.The internal combustion engines seem to have almost complete dominance of the automotive field.The internal combustion engine,as its name indicates,burns fuel within the cylinders and converts the expanding force of the combustion into rotary force used to propel the vehicle. 事实上,按动力来源分发动机有很多种,如电动机、蒸汽机、外燃机等。然而内燃机似乎在发动机领域有着绝对的统治地位。就像其字面意思一样,内燃机的染料在气缸内燃烧,通过将燃烧产生气体的膨胀力转换成转动力来驱动发动机前进。 Engine is the power source of the automobile.Power is produced by the linear motion of a piston in a cylinder.However,this linear motion must be changed into rotary motion to turn the wheels of cars or trucks.The puston attached to the top of a connecting rod by a pin,called a piston pin or wrist pin.The bottom of the connecting rod is attached to the crankshaft.The connecting rod transmits the up-and-down motion of the piston to the crankshaft,which changes it into rotary motion.The connecting rod is mounted on the crankshaft with large bearings called rod bearing.Similar bearings, called main bearings,are used to mount the crankshaft in the block. 发动机是整部车的动力来源。能量来自于活塞在气缸内的(往复)直线运动。然而这种(往复)直线运动必须要转换成旋转运动才能驱动车轮。活塞与连杆通过一个销来连接,这个销称为活塞销。连杆的下部连接于曲拐。连杆把活塞的上下往复运动传递给曲拐,从而将往复直线运动转变成旋转运动。连杆和曲拐的连接使用大的轴承,称之为连杆轴承,类似的轴承也用于将曲轴连接到机体,称之为主轴承。 They are generally two different types of cooling system:water-cooling system and air-cooling system.Water-cooling system is more common.The cooling medium, or coolant, in them is either water or some low-freezing liquid, called antifreeze.A water-cooling system consists of the engine water jacket, thermostat, water pump, radiator, radiator cap, fan, fan drive belt and neccessary hoses. 主要有两种类型的冷却系统:水冷和风冷。水冷系统更为普遍。系统所用冷却介质或是冷却液常委水或其他低凝固点液体,称为抗凝剂。一个完整的水冷系统包括机体水套,节温器,水泵,散热器,散热器罩,风扇,风扇驱动皮带和必需的水管。 A water-cooling system means that water is used as a cooling agent to circulate through the engine to absorb the heat and carry it to the radiator for disposal.The ebgine is cooled mainly through heat transfer and heat dissipation.The heat generated by the mixture burned in the engine must be transferred from the iron or aluminum cylinder to the waterin the water jacket.The outside of the water jacket dissipates some of the heat to the air surrounding it, but most of the heat is carried by the cooling water to the radiator for dissipation.When the coolant temperature in the system reaches 90°,the termostat valve open fully, its slanted edge shutting off

土木专业英语翻译作业

桂林理工大学土木与建筑工程学院 土木工程专业英语外文翻译,中文翻译 姓名:马凤志 专业:土木应用 班级:10级9班 学号:3100510939

原文

中文翻译 The Influence of Concrete Compaction on the Strength of Concrete Filled Steel Tubes 压实混凝土对混凝土强度的影响 Lin-Hai Han School of Civil Engineering, Harbin University of Civil Engineering and Architecture, Haihe Road 202, PO Box 689, Harbin 150090, P.R. China 韩林海,哈尔滨建筑大学,土木与建筑工程学院,海河路202号,邮政信箱,689,哈尔滨,150090 中国 ABSTRACT: Tests on twenty-one concrete filled steel tubes to investigate the influence of compaction methods on the strength of concrete filled steel tubular members are reported. 摘要:测试二十一钢管混凝土试验,研究了钢管对混凝土构件强度压实方法的影响报告。 Two parameters were investigated, including slenderness ratio and load eccentricity. 对两个参数进行研究,包括长细比和荷载偏心。 It was found that better compaction of concrete resulted in higher values of the ultimate strength of concrete filled steel

汽车专业英语课文翻译4

Fuel Supply System of Gasoline Engine(UNIT SEVEN) All the gasoline engines have substantially identical fuel systems and run on a mixture consisting of fuel vapor and air. The fuel system comprises the units designed to store, clear and deliver fuel, the units intended to clean air and a unit for preparing a mixture from fuel vapor and air. In a fuel system different components are used to supply fuel from the fuel tank into the engine cylinder. Some of the important components are fuel tank, fuel pump, fuel filter, carburetor, intake manifold and fuellines or tubes connecting the tank, pump and the carburetor. The fuel tank is a fuel container used for storing fuel. It is made of sheet metal. It is attached to the vehicle frame with metal traps and is located at the rear of the vehicle. They are mounted in a boot or boot-floor pan in case of front-engined cars and small commercial vehicles. In order to strengthen the tank as well as to prevent surging of fuel when the vehicle rounds a curve of suddenly stops, baffle plates are attached to the inside of the tank. A cap is used to close the filler opening of the tank. The fuel line is attached at or near the bottom of the tank with a filtering element placed at the connection. The other components of the fuel tank are the fuel gauge sending unit, a vent pipe, receiving unit. To prevent the dirt and water from entering the luggage compartment, a sealing strip is fitted between the fuel tank and boot floor pan. Moreover to limit the transmission of frame distortion to the tank giving rise to squeaking as the metal parts get rubbed together, rubber or felt pads are often fitted between the mountings and the tank. Provision is also made against drumming of the tank by these mountings. The tank may be placed at the side of the chassis frame for convenience in case of large commercial vehicles. The length of the connecting lines or tubes from the tank to the carburetor is also restricted by this at the same time. A porous filter is attached to the outlet lines. By drawing fuel from the tank through the filter, any water in the bottom of the tank as well as any dirt into the fuel gathers on the surface of the filter. To keep the fuel always under atmospheric pressure, the filter pipe or tank is vented. In order to prevent dirt in the fuel from entering the fuel pump or carburetor, fuel filters and screens are used in the fuel system. If the dirt is not removed from the fuel, the normal operation of these units will be prevented. The engine performance will also be reduced.

上海海洋大学专业英语期末翻译

Analog computers are analog devices. That is, they have continuous states rather than discrete numbered states. An analog computer can represent fractional or irrational values exactly, with no round-off. Analog computers are almost never used outside of experimental settings. 模拟计算机是模拟设备。也就是说,他们是连续状态而不是离散的有限状态。一个模拟计算机可以精确代表小数或无理数,没有舍入。模拟计算机几乎从不被使用在实验设置以外。 A processor typically contains an arithmetic/logic unit (ALU), control unit( including processor flags, flag register, or status register), internal buses, and sometimes special function units( the most common special function unit being a floating point unit for floating point arithmetic). 一个处理器通常包含一个算术/逻辑单元(运算器),控制单元(包括处理器标志,标志寄存器,或状态寄存器),内部总线,有时特殊功能单元(最常见的特殊功能单元作为一个浮点单元用于浮点运算)。 CISC stands for Complex Instruction Set Computer. Mainframe computers and minicomputers were CISC processors, with manufacturers competing to offer the most useful instruction sets. Many of the first two generations of microprocessors were also CISC. CISC代表复杂指令集计算机。大型计算机和小型计算机是CISC处理器,与制造商竞争提供最有用的指令集。微处理器的前两代中许多也是CISC。 Lesson 2 Supercomputer is a broad term for one of the fastest computers currently available. Supercomputers are very expensive and are employed for specialized applications that require immense mounts of mathematical calculations (number crunching). 超级计算机是一个广泛的术语,因为它是目前可用的最快的计算机之一。超级计算机是非常昂贵的,并且它被用于需要大量的数学计算(数字运算)的专门应用。 It is a midsize computer. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstation. But in general, a minicomputer is a multiprocessing system capable of supporting up to 200 users simultaneously. 它是一个中型计算机。在过去的十年中,大的小型机和小的大型机之间的区别已经模糊,然而,有小的小型机和工作站之间的区别。但在一般情况下,一个小型机是一个能够同时支持多达200个用户的多处理系统。 Workstations generally come with a large, high-resolution graphics screen, a large amount of RAM, built-in network support, and a graphical user interface. Most workstations also have a mass storage device such as disk drive, but a special type of workstation, called a diskless workstation, comes without a disk drive. 工作站一般都配有一个大的,高分辨率的图形屏幕,大量的内存,内置网络支持以及一个图形用户界面。大多数工作站也有一个大容量存储设备如磁盘驱动器,但是一种特殊类型的工作站,被称为无盘工作站,是不带磁盘驱动器的。

报纸杂志名称翻译词汇精编版

报纸杂志名称翻译词汇

daily 日报 morning edition 晨报 evening edition 晚报 quality paper 高级报纸 popular paper 大众报纸 evening paper 晚报 government organ 官报 part organ 党报 trade paper 商界报纸 Chinese paper 中文报纸 English newspaper 英文报纸 vernacular paper 本国文报纸 Japanese paper 日文报纸 political news 政治报纸 Newspaper Week 新闻周刊 the front page 头版,第一版 bulldog edition 晨版 article 记事 headline 标题 banner headline 头号大标题 byline 标题下署名之行 dateline 日期、发稿地之行

hot news 最新新闻 exclusive news 独家新闻 scoop 特讯 feature 特写,花絮 criticism 评论 editorial 社论 review, comment 时评 book review 书评 topicality 时事问题 city news 社会新闻 column 栏 letters 读者投书栏 general news column 一般消息栏cartoon, comics 漫画 cut 插图 weather forecast 天气预报 serial story 新闻小说 obituary notice 讣闻 public notice 公告advertisement 广告 classified ad 分类广告

汽车专业英语翻译

INTERNAL COMBUSTION ENGINE 引擎燃烧室 1. principle of operation 原理 Engine and power : Engine is used to produce power. The chemical energy in fuel is converted to heat by the burning of the fuel at a controlled rate. This process is called combustion. If engine combustion occurs with the power chamber. ,the engine is called internal combustion engine. If combustion takes place outside the cylinder, the engine is called an external combustion engine. Engine used in automobiles are internal combustion heat engines. Heat energy released in the combustion chamber raises the temperature of the combustion gases with the chamber. The increase in gas temperature causes the pressure of the gases to increase. The pressure developed within the combustion chamber is applied to the head of a piston to produce a usable mechanical force, which is then converted into useful mechanical power. 译: 引擎和能量: 引擎为汽车提供能量,燃料的化学能通过燃烧,转化为热能,这个过程叫燃烧。假如燃烧在燃烧室,这样的发动机叫内燃机。假如燃烧在气缸外,这样的发动机叫外燃机。 用在汽车上的一般是内燃机,热能在燃烧室释放,燃烧室气体温度升高。气体温度的升高使气体的压力曾加,燃烧室内的高压气体作用在活塞头部产生可以利用的化学能,化学能转化为机械能。 Engine T erms : Linking the piston by a connecting rod to a crankshaft causes the gas to rotate the shaft through half a turn. The power stroke “uses up” the gas , so means must be provided to expel the burnt gas and recharge the cylinder with a fresh petrol-air mixture :this control of gas movement is the duty of the valves ;an inlet valve allows the new mixture to enter at the right time and an exhaust valve lets out the burnt gas after the gas has done its job. Engine terms are : TDC(Top Dead Center):the position of the crank and piston when the piston is farther away from the crankshaft. BDC(Bottom Dead Center):the position of the crank and piston when the piston is nearest to the crankshaft. Stroke : the distance between BDC and TDC; stroke is controlled by the crankshaft. Bore : the internal diameter of the cylinder. Swept volume : the volume between TDC and BDC Engine capacity : this is the swept volume of all the cylinder e.g. a four-stroke having a capacity of two liters(2000cm) has a cylinder swept volume of 50cm. Clearance volume: the volume of the space above the piston when it is at TDC. Compression ratio = (swept vol + clearance vol)\(clearance vol) Two-stroke : a power stroke every revolution of the crank.

专业英语翻译作业译文

专业英语翻译作业译文 1.科学家们认为,这样微弱的粒子正则轨道实际上是不存在的。的想法现在已被事实否定了。 2.虽然小行星很小很微弱,天文学家已经知道很多关于它们的大小,形状和组合物,通过使用各种直接和间接的技术。例如,它是已知的许多小行星的亮度的周期性变化。 3.随着疾病的进展,大肌肉也稳步增长疲软。如果不治疗,患者变得瘫痪有呼吸非常困难,并最终死亡。 4.将信息从计算机的一部分转移到另一个取决于电流进行了线。 5.只有两件事是天文观测----站立的地方和地方看需要。 6.太阳风严重扭曲地球磁场,把它拖了一个长长的尾巴。 7.使用计算机,我们组成了一系列的合成歌曲的混合自然音节为不同的模式。 8.苍头燕雀的显示,找出正确的声音模仿的本能,这表明本能学习鸟类作为他们发展他们的歌曲一样重要。 9.We know from the fossil record that our ancestors and other intelligent creatures,the australopithecines,branched off from an apelike creature 2.5 million to 3 million years ago ,and coexisted until the australopithecines died out a little less than a million years ago.Stone tools and other evidence at campsites that date form about 2,000,000 B.C.indicate that some form of australopithecine performed human activities ------ making tools,sharing food and working together. 我们知道从化石记录我们的祖先和其他智能生物,猿,分枝从远古的生物2500000到3000000年前,南方古猿和共存直到死了比一百万年前少了一点。石器和露营地,日期约2000000 b.c.表明某种形式的南方古猿表现人类活动------制作工具的其他证据,分享食物,一起工作。 10.properties of metals Metals are of great use to mankind because of their useful engineering properties. Strength is one of the important properties of metals .It enables them to resist external loads without incurring structural damages.Metals, possessing toughness, a property of absorbing considerable energy before fracture,bend rather than break. Another property of metals is elasticity.Because of their elasticity,metals subjected to an external load are distorted or stained, and return to their original dimensions when the load is released if the load is not too great. Ductility is the capacity of a metal to be permanently deformed in tension without breaking. That is why some metals, such as copper and aluminum, can be drawn erom a large into a smaller diameter of wire.

英语报刊杂志课文翻译汇总

第一单元 When the University of California at Los Angeles put Rep. Jerry Lewis (R-Calif.) on the cover of this winter’s alumni bulletin, it was a tribute to a distinguished graduate who is so close to his alma mater that he named his dog Bruin, after UCLA’s revered symbol. 美国加州大学洛杉矶分校在今年冬季毕业生期刊封面刊登美国国会议员杰尔. 刘易斯(加州共和党人),对与其母校的关系密切得能用美国加州大学洛杉矶分校吉祥物将其宠狗取名为布轮熊的杰出毕业生大肆颂扬。 But the cover story, which was engineered in part by the University of California’s government relation office in Washington, was also a shrewd ploy to cement relations with a key member of the House Appropriations Committee. 但是在某种程度上由加州大学华盛顿政府关系办公室策划的这一封面故事也是密切与美国国会众院拨款委员会某一关键委员的精明手段。 As Congress takes up President Bush’s fiscal 2005 budget proposal, which cuts some basic research programs vital to universities, the higher education community is using every lobbying tool at its disposal to protect its interests. 在美国国会受理布什总统提交的砍掉了对大学至关重要的一些基本

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