翻译对应文章Introduction to digital temperature sensor DS1820
数字温度传感器DS1820的介绍
特性：
·独特的单线接口，只需1 个接口引脚即可通信；
·多点（multidrop）能力使分布式温度检测应用得以简化；
·不需要外部元件；
·可用数据线供电；
·不需备份电源；
·测量范围从-55至+125℃，增量值为0.5℃。等效的华氏温度范围是-67 F 至257 F，增量值为0.9 F；
·以9位数字值方式读出温度；
·在1秒（典型值）内把温度变换为数字；
·用户可定义的，非易失性的温度告警设置；
·告警搜索命令识别和寻址温度在编定的极限之外的器件（温度告警情况）；·应用范围包括恒温控制，工业系统，消费类产品，温度计或任何热敏系统。
详细说明
DS1820有三个主要的数据部件：1）64位激光lasered ROM；2）温度灵敏元件，和3）非易失性温度告警触发器TH和TL。器件从单线的通信线取得其电源，在信号线为高电平的时间周期内，把能量贮存在内部的电容器中，在单信号线为低电平的时间期内断开此电源，直到信号线变为高电平重新接上寄生（电容）电源为止。作为另一种可供选择的方法，DS1820也可以用外部5V电源供电。与DS1820 的通信经过一个单线接口。在单线接口情况下，在ROM 操作未定建立之前不能使用存贮器和控制操作。主机必须首先提供五种ROM操作命令之一；
1）Read ROM(读ROM)；
2)Match ROM(符合ROM)；
3)Search ROM(搜索ROM)；
4)Skip ROM(跳过ROM)；
5）Alarm Search(告警搜索)；
这些命令对每一器件的64位激光ROM 部分进行操作，如果在单线上有许多器件，那么可以挑选出一个特定的器件，并给总线上的主机指示存在多少器件及其类型。在成功地执行了ROM 操作序列之后，可使用存贮器和控制操作，然后主机可以提供六种存贮器和控制操作命令之一。
一个控制操作命令指示DS1820 完成温度测量。该测量的结果将放入DS1820 的高速暂存（便笺式）存贮器（Scratchpad memory），通过发出读暂存存储器内容的存储器操作命令可以读出此结果。每一温度告警触发器TH和TL构成一个字节的EEPROM。如果不对DS1820 施加告警搜索命令，这些寄存器可用作通用用户存储器使用存储器，操作命令可以写TH 和TL 对这些寄存器的读访问。所有数据均以最低有效位在前的方式被读写。
寄生电源
方框图(图1)示出寄生电源电路。当I/O或VDD 引脚为高电平时，这个电路便“取”得电源。只要符合指定的定时和电压要求，I/O将提供足够的功率（标题为“单总线系统”一节）。寄生电源的优点是双重的：
1）利用此引脚，远程温度检测无需本地电源；
2）缺少正常电源条件下也可以读ROM；
为了使DS1820能完成准确的温度变换，当温度变换发生时，I/O 线上必须提供足够的功率。因为DS1820 的工作电流高达1mA ，5K 的上拉电阻将使I/O 线没有足够的驱动能力。如果几个SD1820 在同一条I/O 线上而且同时变换，那么这一问题将变得特别尖锐。
有两种方法确保DS1820 在其有效变换期内得到足够的电源电流。第一种方法是发生温度变换时，在I/O 线上提供一强的上拉。如图2所示，通过使用一个MOSFET 把I/O 线直接拉到电源可达到这一点。当使用寄生电源方式时VDD 引脚必须连接到地。
向DS1820 供电的另外一种方法是通过使用连接到VDD 引脚的外部电源，如图3 所示这种方法的优点是在I/O 线上不要求强的上拉。总线上主机不需向上连接便在温度变换期间使线保持高电平。这就允许在变换时间内其它数据在单线上传送。此外，在单线总线上可以放置任何数目的DS1820 ，而且如果它们都使用外部电源，那么通过发出跳过（Skip） ROM 命令和接着发出变换（Convert） T 命令，可以同时完成温度变换。注意只要外部电源处于工作状态，GND（地引）脚不可悬空。
在总线上主机不知道总线上DS1820 是寄生电源供电还是外部VDD 供电的情况下，在DS1820 内采取了措施来通知采用的供电方案。总线上主机通过发出跳过（Skip）ROM 的操作约定，然后发出读电源命令，可以决定是否有需要强上拉的DS1820 在总线上。在此命令发出后，主机接着发出读时间片。如果是寄生供电，DS1820 将在单线总线上送回“0”；如果由VDD 引脚供电，它将送回1。如果主机接收到一个“0”，它知道它必须在温度变换期间在I/O 线上供一个强的上拉。有关此命令约定的详细说明见存贮器命令功能一节。
运用——测量温度
SDS1820 通过使用在板（on-board）温度测量专利技术来测量温度。温度测量电路的方框图见图4 所示。
DS1820 通过门开通期间内低温度系数振荡器经历的时钟周期个数计数来测量温度，如果在门开通期结束前计数器达到零，那么温度寄存器—它也被予置到-55℃的数值—将增量，指示温度高于-55℃。
同时，计数器用钭率累加器电路所决定的值进行予置。为了对遵循抛物线规
律的振荡器温度特性进行补偿，这种电路是必需的。时钟再次使计数器计值至它达到零。如果门开通时间仍未结束，那么此过程再次重复。
钭率累加器用于补偿振荡器温度特性的非线性，以产生高分辩率的温度测量。通过改变温度每升高一度，计数器必须经历的计数个数来实行补偿。因此，为了获得所需的分辩率，计数器的数值以及在给定温度处每一摄氏度的计数个数（钭率累加器的值）二者都必须知道。
此计算在DS1820 内部完成以提供0.5℃的分辩率。温度读数以16位、符号扩展的二进制补码读数形式提供表1 说明输出数据对测量温度的关系。数据在单线接口上串行发送。DS1820 可以以0.5℃的增量值，在0.5℃至+125℃的范围内测量温度。对于应用华氏温度的场合必须使用查找表或变换系数。
注意在DS1820 中温度是以1/2 LSB 最低有效位形式表示时产生以下9 位格式：
最高有效（符号）位被复制到存储器内两字节的温度寄存器中较高MSB 的所有位，这种“符号扩展”产生了如表1 所示的16 位温度读数。
以下的过程可以获得较高的分辩率。首先，读温度，并从读得的值截去0.5℃位(最低有效位)。这个值便是TEMP_READ。然后可以读留在计数器内的值。此值是门开通期停止之后计数剩余（COUNT_REMAIN）。
所需的最后一个数值是在该温度处每一摄氏度的计数个数（COUNT_PER_C）。于是，用户可以使用下式计算实际温度：
硬件接法
根据定义，单线总线只有一根线：这一点是重要的，即线上的第一个器件能在适当的时间驱动该总线。为了做到这一点，第一个连接到单线总线上的器件必须具有漏极开路或三态输出。DS1820 的单线接口（I/O 引脚是漏极开路的，其内部等效电路如图9 所示）多站multidrop 总线由单线总线和多个与之相连的从属器件组成。单线总线要求近似等于5k的上拉电阻。
单线总线的空闲状态是高电平。不管任何原因，如果执行需要被挂起，那么，若要重新恢复执行，总线必须保持在空闲状态。如果不满足这一点且总线保持在低电平时间大于480us，那么总线上所有器件均被复位。
存在脉冲（presence pulse）使总线主机知道DS1820 在总线上并已准备好工作。详情见“单线信号”一节。
处理顺序
经过单线接口访问DS1820 的协议（protocol）如下：
·初始化
·ROM 操作命令
·存贮器操作命令
·处理/数据
初始化
单线总线上的所有处理均从初始化序列开始。初始化序列包括总线主机发出一复位脉冲，接着由从属器件送出存在脉冲。
2.8.2.2 ROM 操作命令
一旦总线主机检测到从属器件的存在，它便可以发出器件ROM 操作命令之一。所有ROM 操作命令均为8 位长，这些命令列表如下（参见图6 的流程图）。
·Read ROM(读ROM) [33h]
此命令允许总线主机读DS1820 的8 位产品系列编码，唯一的48 位序列号，以及8 位的CRC。此命令只能在总线上仅有一个DS1820 的情况下可以使用。如果总线上存在多于一个的从属器件，那么当所有从片企图同时发送时将发生数据冲突的现象（漏极开路会产生“线与”的结果）。
·Match ROM(“符合”ROM) [55h]
“符合”ROM 命令。后继以64 位的ROM 数据序列，允许总线主机对多点总线上特定的DS1820寻址。只有与64 位ROM 序列严格相符的DS1820 才能对后继的存贮器操作命令作出响应。所有与64位ROM 序列不符的从片将等待复位脉冲。此命令在总线上有单个或多个器件的情况下均可使用
·(“跳过”ROM ) [CCh]
在单点总线系统中，此命令通过允许总线主机不提供64 位ROM 编码而访问存储器操作来节省时间。如果在总线上存在多于一个的从属器件而且在Skip ROM 命令之后发出读命令，那么由于多个从片同时发送数据，会在总线上发生数据冲突（漏极开路下拉会产生“线与”的效果）。
·( 搜索ROM) [F0h]
当系统开始工作时，总线主机可能不知道单线总线上的器件个数或者不知道其64 位ROM 编码。搜索ROM 命令允许总线主机使用一种“消去”（elimination）处理来识别总线上所有从片的64 位 ROM 编码。
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外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
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Programmable logic controller A programmable logic controller (PLC) or programmable controller is a digital computer used for automation of electromechanical processes, such as control of machinery on factory assembly lines, amusement rides, or lighting fixtures. PLCs are used in many industries and machines. Unlike general-purpose computers, the PLC is designed for multiple inputs and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory. A PLC is an example of a real time system since output results must be produced in response to input conditions within a bounded time, otherwise unintended operation will result. 1.History The PLC was invented in response to the needs of the American automotive manufacturing industry. Programmable logic controllers were initially adopted by the automotive industry where software revision replaced the re-wiring of hard-wired control panels when production models changed. Before the PLC, control, sequencing, and safety interlock logic for manufacturing automobiles was accomplished using hundreds or thousands of relays, cam timers, and drum sequencers and dedicated closed-loop controllers. The process for updating such facilities for the yearly model change-over was very time consuming and expensive, as electricians needed to individually rewire each and every relay. In 1968 GM Hydramatic (the automatic transmission division of General Motors) issued a request for proposal for an electronic replacement for hard-wired relay systems. The winning proposal came from Bedford Associates of Bedford, Massachusetts. The first PLC, designated the 084 because it was Bedford Associates' eighty-fourth project, was the result. Bedford Associates started a new company dedicated to developing, manufacturing, selling, and servicing this new product: Modicon, which stood for MOdular DIgital CONtroller. One of the people who worked on that project was Dick Morley, who is considered to be the "father" of the PLC. The Modicon brand was sold in 1977 to Gould Electronics, and later acquired by German Company AEG and then by French Schneider Electric, the current owner. One of the very first 084 models built is now on display at Modicon's headquarters in North Andover, Massachusetts. It was presented to Modicon by GM, when the unit was retired after nearly twenty years of uninterrupted service. Modicon used the 84
Advantages of Managed Code Microsoft intermediate language shares with Java byte code the idea that it is a low-level language witha simple syntax , which can be very quickly translated intonative machine code. Having this well-defined universal syntax for code has significant advantages. Platform independence First, it means that the same file containing byte code instructions can be placed on any platform; atruntime the final stage of compilation can then be easily accomplished so that the code will run on thatparticular platform. In other words, by compiling to IL we obtain platform independence for .NET, inmuch the same way as compiling to Java byte code gives Java platform independence. Performance improvement IL is actually a bit more ambitious than Java bytecode. IL is always Just-In-Time compiled (known as JIT), whereas Java byte code was ofteninterpreted. One of the disadvantages of Java was that, on execution, the process of translating from Javabyte code to native executable resulted in a loss of performance. Instead of compiling the entire application in one go (which could lead to a slow start-up time), the JITcompiler simply compiles each portion of code as it is called (just-in-time). When code has been compiled.once, the resultant native executable is stored until the application exits, so that it does not need to berecompiled the next time that portion of code is run. Microsoft argues that this process is more efficientthan compiling the entire application code at the start, because of the likelihood that large portions of anyapplication code will not actually be executed in any given run. Using the JIT compiler, such code willnever be compiled.
英文翻译说明 1. 英文翻译文章输成word，5号新罗马（New Times Roman）字体，1.5倍行间距，将来方便打印和一起装订；英文中的图表要重新画，禁止截图。 2. 整篇论文1.5倍行间距，打印时，用B5纸，版面上空2.5cm，下空2cm，左空2.5cm，右空2cm（左装订）。 3. 论文翻译后的摘要用五号宋体，正文小四号宋体、英文和数字用新罗马（New Times Roman）12、参考文献的内容用五号字体。图和表头用五号字体加粗并居中，图和表中的内容用五号字体。论文翻译的作者用五号字体加粗。 论文大标题………小三号黑体、加黑、居中 第二层次的题序和标题………小四号黑体、加黑、居中 第三层次的题序和标题………小四号宋体、加黑、居中 正文……………………………小四号宋体、英文用新罗马12 页码……………………………小五号居中，页码两边不加修饰符 4. 论文中参考文献严格按照下述排版。 专著格式：序号.编著者.书名[M].出版地: 出版社, 年代, 起止页码 期刊论文格式：序号.作者.论文名称[J]. 期刊名称, 年度, 卷(期): 起止页码 学位论文格式：序号.作者.学位论文名称[D]. 发表地: 学位授予单位, 年度 例子: (1).胡千庭, 邹银辉, 文光才等. 瓦斯含量法预测突出危险新技术[J]. 煤炭学报, 2007.32(3): 276-280. (2). 胡千庭. 煤与瓦斯突出的力学作用机理及应用研究[D]. 北京: 中国矿业大学(北京), 2007. (3). 程伟. 煤与瓦斯突出危险性预测及防治技术[M]. 徐州: 中国矿业大学出版社, 2003.
使用高级分析法的钢框架创新设计 1．导言 在美国，钢结构设计方法包括允许应力设计法(ASD)，塑性设计法(PD)和荷载阻力系数设计法(LRFD)。在允许应力设计中，应力计算基于一阶弹性分析，而几何非线性影响则隐含在细部设计方程中。在塑性设计中，结构分析中使用的是一阶塑性铰分析。塑性设计使整个结构体系的弹性力重新分配。尽管几何非线性和逐步高产效应并不在塑性设计之中，但它们近似细部设计方程。在荷载和阻力系数设计中，含放大系数的一阶弹性分析或单纯的二阶弹性分析被用于几何非线性分析，而梁柱的极限强度隐藏在互动设计方程。所有三个设计方法需要独立进行检查，包括系数K计算。在下面，对荷载抗力系数设计法的特点进行了简要介绍。 结构系统内的内力及稳定性和它的构件是相关的，但目前美国钢结构协会（AISC）的荷载抗力系数规范把这种分开来处理的。在目前的实际应用中，结构体系和它构件的相互影响反映在有效长度这一因素上。这一点在社会科学研究技术备忘录第五录摘录中有描述。 尽管结构最大内力和构件最大内力是相互依存的（但不一定共存），应当承认，严格考虑这种相互依存关系，很多结构是不实际的。与此同时，众所周知当遇到复杂框架设计中试图在柱设计时自动弥补整个结构的不稳定（例如通过调整柱的有效长度）是很困难的。因此，社会科学研究委员会建议在实际设计中，这两方面应单独考虑单独构件的稳定性和结构的基础及结构整体稳定性。图28.1就是这种方法的间接分析和设计方法。
在目前的美国钢结构协会荷载抗力系数规范中，分析结构体系的方法是一阶弹性分析或二阶弹性分析。在使用一阶弹性分析时，考虑到二阶效果，一阶力矩都是由B1,B2系数放大。在规范中，所有细部都是从结构体系中独立出来，他们通过细部内力曲线和规范给出的那些隐含二阶效应，非弹性，残余应力和挠度的相互作用设计的。理论解答和实验性数据的拟合曲线得到了柱曲线和梁曲线，同时Kanchanalai发现的所谓“精确”塑性区解决方案的拟合曲线确定了梁柱相互作用方程。 为了证明单个细部内力对整个结构体系的影响，使用了有效长度系数，如图28.2所示。有效长度方法为框架结构提供了一个良好的设计。然而，有效长度方法的
软件专业毕业论文外文文献中英文翻译 Object landscapes and lifetimes Tech nically, OOP is just about abstract data typing, in herita nee, and polymorphism, but other issues can be at least as importa nt. The rema in der of this sect ion will cover these issues. One of the most importa nt factors is the way objects are created and destroyed. Where is the data for an object and how is the lifetime of the object con trolled? There are differe nt philosophies at work here. C++ takes the approach that con trol of efficie ncy is the most importa nt issue, so it gives the programmer a choice. For maximum run-time speed, the storage and lifetime can be determined while the program is being written, by placing the objects on the stack (these are sometimes called automatic or scoped variables) or in the static storage area. This places a priority on the speed of storage allocatio n and release, and con trol of these can be very valuable in some situati ons. However, you sacrifice flexibility because you must know the exact qua ntity, lifetime, and type of objects while you're writing the program. If you are trying to solve a more general problem such as computer-aided desig n, warehouse man ageme nt, or air-traffic con trol, this is too restrictive. The sec ond approach is to create objects dyn amically in a pool of memory called the heap. In this approach, you don't know un til run-time how many objects you n eed, what their lifetime is, or what their exact type is. Those are determined at the spur of the moment while the program is runnin g. If you n eed a new object, you simply make it on the heap at the point that you n eed it. Because the storage is man aged dyn amically, at run-time, the amount of time required to allocate storage on the heap is sig ni fica ntly Ion ger tha n the time to create storage on the stack. (Creat ing storage on the stack is ofte n a si ngle assembly in structio n to move the stack poin ter dow n, and ano ther to move it back up.) The dyn amic approach makes the gen erally logical assumpti on that objects tend to be complicated, so the extra overhead of finding storage and releas ing that storage will not have an importa nt impact on the creati on of an object .In additi on, the greater flexibility is esse ntial to solve the gen eral program ming problem. Java uses the sec ond approach, exclusive". Every time you want to create an object, you use the new keyword to build a dyn amic in sta nee of that object. There's ano ther issue, however, and that's the lifetime of an object. With Ian guages that allow objects to be created on the stack, the compiler determines how long the object lasts and can automatically destroy it. However, if you create it on the heap the compiler has no kno wledge of its lifetime. In a Ianguage like C++, you must determine programmatically when to destroy the
英文翻译 英语原文： . Introducing Classes The only remaining feature we need to understand before solving our bookstore problem is how to write a data structure to represent our transaction data. In C++ we define our own data structure by defining a class. The class mechanism is one of the most important features in C++. In fact, a primary focus of the design of C++ is to make it possible to define class types that behave as naturally as the built-in types themselves. The library types that we've seen already, such as istream and ostream, are all defined as classesthat is,they are not strictly speaking part of the language. Complete understanding of the class mechanism requires mastering a lot of information. Fortunately, it is possible to use a class that someone else has written without knowing how to define a class ourselves. In this section, we'll describe a simple class that we canuse in solving our bookstore problem. We'll implement this class in the subsequent chapters as we learn more about types,expressions, statements, and functionsall of which are used in defining classes. To use a class we need to know three things: What is its name? Where is it defined? What operations does it support? For our bookstore problem, we'll assume that the class is named Sales_item and that it is defined in a header named Sales_item.h. The Sales_item Class The purpose of the Sales_item class is to store an ISBN and keep track of the number of copies sold, the revenue, and average sales price for that book. How these data are stored or computed is not our concern. To use a class, we need not know anything about how it is implemented. Instead, what we need to know is what operations the class provides. As we've seen, when we use library facilities such as IO, we must include the associated headers. Similarly, for our own classes, we must make the definitions associated with the class available to the compiler. We do so in much the same way. Typically, we put the class definition into a file. Any program that wants to use our class must include that file. Conventionally, class types are stored in a file with a name that, like the name of a program source file, has two parts: a file name and a file suffix. Usually the file name is the same as the class defined in the header. The suffix usually is .h, but some programmers use .H, .hpp, or .hxx. Compilers usually aren't picky about header file names, but IDEs sometimes are. We'll assume that our class is defined in a file named Sales_item.h. Operations on Sales_item Objects
1. Introduction America is one of the countries that speak English. Because of the special North American culture, developing history and the social environment, American English has formed its certain unique forms and the meaning. Then it turned into American English that has the special features of the United States. American English which sometimes also called United English or U.S English is the form of the English language that used widely in the United States .As the rapid development of American economy, and its steady position and strong power in the world, American English has become more and more widely used. As in 2005, more than two-thirds of English native speakers use various forms of American English. The philologists of the United States had divided the English of the United States into four major types: “America n creating”; “Old words given the new meaning”; “Words that eliminated by English”;“The phonetic foreign phrases and the languages that are not from the English immigrates”[1]. Compared to the other languages, American English is much simple on word spelling, usage and grammar, and it is one of the reasons that American English is so popular in the world. The thesis analyzes the differences between American English and British English. With the main part, it deals with the development of American English, its peculiarities compared to that of British English, its causes and tendency. 2. Analyses the Differences As we English learners, when we learning English in our junior or senior school, we already came across some words that have different spellings, different pronunciations or different expressions, which can be represented by following contrasted words: spellings in "color" vs. "colour"; pronunciations in "sec-re-ta-ry" vs. "sec-re-try";
Application of PLC PLC is one kind specially for the digital operation operation electronic installation which applies under the industry environment designs. It uses may the coding memory, uses for in its internal memory operation and so on actuating logic operation, sequence operation, time, counting and arithmetic operation instructions, and can through digital or the simulation-like input and the output, controls each type the machinery or the production process. PLC and the related auxiliary equipment should according to form a whole easy with the industrial control system, easy to expand its function the principle to design.” In the 1970s the last stage, the programmable controller entered the practical application development phase, the computer technology has introduced in comprehensively the programmable controller, causes its function to have the leap. The higher operating speed, the subminiature volume, the more reliable industry antijamming design, the simulation quantity operation, the PID function and the extremely high performance-to-price ratio has established it in the modern industry status. In the early-1980s, the programmable controller has obtained the widespread application in the advanced industrial nation. This time programmable controller develops the characteristic is large-scale, the high velocity, the high performance, the product seriation. This stage's another characteristic is in the world produces the programmable controller's country to increase day by day, the output rises day by day. This symbolizes that the programmable controller marched into the mature stage. The 20th century last stage, the programmable controller's development characteristic was even more adapts in the modern industry need. From the control scale, this time has developed the large-scale machinery and subminiature machine; From the control, was born various special function unit, used in the pressure, the temperature, the rotational speed, the displacement and so on all kinds of control situation; From product necessary ability, has produced each kind of man-machine contact surface unit, the correspondence unit, caused to apply the programmable controller's industrial control equipment necessary to be easier. At present, the programmable controller in domain and so on machine manufacture, petroleum chemical industry, metallurgy steel and iron, automobile, light industry applications obtained the considerable development.