机电专业英语第2版13Unit 13.
教育技术学专业英语unit13textb原文加翻译
Four Types of Automated Instructional Design Tools Expert System An An expert expert expert system system system contains contains contains a a a domain-specific domain-specific domain-specific knowledge-base knowledge-base and performs decision-making and analysis functions for the designer using natural language queries. Expert systems for instructional design have been developed to provide advice to novice instructional designers and to facilitate the development process for experienced designers. ID ID Expert Expert Expert from from from the the the ID2 ID2 ID2 Research Group was created to develop Research Group was created to develop and deliver computer-based instruction more efficiently. ID Expert is based based on on on Instructional Instructional Instructional Transaction Transaction Transaction Theory, Theory, Theory, a a a ““second second generation generation generation””theory of instructional design. According to Instructional Transaction Theory, Theory, instruction instruction instruction is is is based based based on on on transactions transactions transactions (sets (sets (sets of of of interactions) interactions) between between the system and the learner in order the system and the learner in order to accomplish a g iven given task. ID Expert assists designers in creating transactions by presenting presenting a a a set set set of of of decision-making decision-making decision-making steps steps steps involving involving involving instructional instructional components, components, formatting, formatting, formatting, resources, resources, resources, etc. etc. etc. ID ID ID Expert Expert Expert is is is considered considered considered a a prototype system and has not yet been released commercially. The United States Air Force Armstrong Laboratory proposed two AID approaches that use expert system technology to provide expertise to novice instructional designers and subject matter experts in the design, production, and implementation of courseware used in Air Force training. Guided Approach to Instructional Design Advising Advising (GAIDA) (GAIDA) (GAIDA) uses uses uses tutorials tutorials tutorials and and and context-specific context-specific context-specific advice advice advice and and examples. Experiment Advanced Instructional Design Advisor (XAIDA) (XAIDA) uses uses uses the the the Instructional Instructional Instructional Transaction Transaction Transaction Theory Theory Theory framework framework framework to to encapsulate context-specific knowledge. Both of these environments are are results results results of of of the the the Advanced Advanced Advanced Instructional Instructional Instructional Design Design Design Adviser Adviser Adviser (AIDA) (AIDA) research project. Reactions to Expert Systems: While expert systems for the instructional instructional design design design can can can teach teach teach theory theory theory validation validation validation and and and function function function as as authoring tools, they are limited by their inability to support analysis and design tasks. ID expert systems attempt to control the instructional design process, a process involving a large number of interrelated elements, and so must rely heavily on the knowledge and experience of the individual practitioner. Several instructional technologists technologists have have have proposed proposed proposed systems systems systems that that that more more more subtly subtly subtly advise advise advise the the instructional designer, rather than prescribe a set of solutions. Advisory Systems Duchastel Duchastel challenges challenges challenges the the the expert expert expert system system system model model model by by by providing providing providing an an advisory advisory system system system model. model. model. Instead Instead Instead of of of controlling controlling controlling the the the problem-solving problem-solving process process with with with expert expert expert knowledge, knowledge, knowledge, advisory advisory advisory systems systems systems assist assist assist or or or coach coach users users in in in accomplishing accomplishing accomplishing a a a given given given task. task. task. A A A prototype prototype prototype for for for the the the advisory advisory system approach is the Instructional Design Advanced W orkbench, Workbench, architecture for a computer-based workbench that supports the cognitive cognitive tasks tasks tasks of of of instructional instructional instructional design design design without without without constraining constraining constraining the the designer. Information Management System Instructional Instructional Design Design Design Environment Environment Environment (IDE) (IDE) (IDE) from from from the the the Institute Institute Institute for for Research on Learning is a computer-aided design environment that supports supports an an an ID ID ID methodology methodology methodology for for for teaching teaching teaching the the the use use use of of of software software software in in real-life problem-solving contexts. I DE IDE IDE helps document design and helps document design and development development options. options. options. It It It is is is intented intented intented for for for experienced experienced experienced instructional instructional designers. Electronic Performance Support Systems Electronic performance support system (EPSS) are self-instructional self-instructional electronic electronic electronic environments environments environments that that that provide provide provide process process process to to “software, guidance, advice, data, tools, and assessment with minimum minimum support support support and and and intervention intervention intervention by by by others others others””. . EPPS EPPS EPPS have have have become become popular in the 1990s for business and education contexts that require “just-in-time just-in-time”” learning learning and and and a a a hign hign hign level level level of of of a a a particular particular particular skill. skill. skill. Some Some example of EPSS are listed below. Building on Duschastel’s “workbench,workbench,”” Paquette et al introduced a a performance performance performance support support support system system system called called called AGD AGD AGD (a (a (a French French French acronym acronym meaning Didactic Engineering W orkbench). AGD provides procedural procedural instructional instructional instructional design design design information information information to to to guide guide guide users users users difining difining the learning system (e.g., amount and nature of objectives). Other performance support systems tools include Designer’s Edge (Figure 13-1) from Allen Communication and Instructional DesignW are are from from from Langevin Langevin Langevin Learning Learning Learning Services Services Services (Langevin (Langevin (Langevin Learning Learning Services). Services). Like Like Like AGD, AGD, AGD, these these these tools tools tools support support support the the the planning planning planning phases phases phases of of instructional instructional design, design, design, but but but contain contain contain a a a much much much more more more general general general advisory advisory component (e.g., context-specific online help, wizard, and tutorials). In contrast to AGD, Designer Designer’’s Edge and Instructional DesignW are lead designers through all tasks involved in instructional design, but place more emphasis on the ultimate production phase. Both tools provide graphical representation of the instructional systems design model, thus leading to additional support for completing each step of the model. Data entered by users are are cross-referenced cross-referenced cross-referenced with with with all all all steps steps steps to to to enhance enhance enhance continuity continuity continuity between between phases. Usable reports and documents such as evaluation instruments, instruments, content content content outlines, outlines, outlines, lesson lesson lesson plans, plans, plans, and and and checklists checklists checklists can can can be be generated by the users. The The primary primary primary difference difference difference between between between the the the two two two products products products lies lies lies in in in their their intented audiences and purposes. Designer ’s Edge is for both novice and and experienced experienced experienced instructional instructional instructional designers designers designers planning planning planning computer-based computer-based instruction. The product includes support for scripts, storyboards and other other CBI CBI CBI production production needs. needs. Integration Integration Integration with with with external external external software software applications is also supported. Instructional Design W are is intented for for course course course designers designers designers and and trainers trainers interested interested interested in in producing producing either either computer-based or classroom training. For this reason ,more suppot is provided for decisions regarding media selection and course and presentation materials (Langevin Learning Services). 自动化教学设计工具的四种类型自动化教学设计工具的四种类型专家系统专家系统包括了一个特定领域的知识库和为设计师使用自然语言查询的执行决策分析功能。
机电一体化专业英语全套教学课件
长春汽车工业高等专科学校
Unit 1 Passage A
Lathe Accessories
Brass Round Stock (铜质圆料) Brass is a nice material to work with, though somewhat expensive compared with aluminum or steel. It can add a nice touch of contrasting color to a project that will be displayed. The alloy most often used for home shop work is 360.
Poor quality drills are easy to find, but they are truly a waste of money. That‘s not to say that you need to buy top quality industrial drills. It’s not always easy to tell a good drill bit from a poor one just by looking and, of course, its even harder if all you have is a picture on a web site or in a catalog. Generally, though, the lowest priced drill sets are the ones to stay away from.
机电工程专业英语第2版
机电工程专业英语第2版Title: The Evolution and Applications of Electromechanical Engineering.Electromechanical engineering, a discipline that merges the fields of electrical engineering and mechanical engineering, has undergone significant advancements in recent years. This融合 of two crucial engineering branches has led to the development of innovative technologies and solutions in various industries.The foundation of electromechanical engineering lies in the understanding of both electrical and mechanical systems. Electrical systems deal with the generation, transmission, and utilization of electrical energy, while mechanical systems focus on the design, analysis, and maintenance of machines and equipment. By combining these two domains, electromechanical engineers are able to create systems that are not only efficient but also reliable.One of the most significant advancements in electromechanical engineering has been the integration of automation and robotics. With the increasing demand for precision and efficiency in manufacturing processes, the role of robots and automated systems has become paramount. Electromechanical engineers are responsible for designing and maintaining these systems, ensuring their seamless operation and optimal performance.Moreover, the integration of sensors and actuators has further enhanced the capabilities of electromechanical systems. Sensors are devices that detect and respond to external stimuli, while actuators convert energy into motion. By incorporating these devices into electromechanical systems, engineers can achieve precise control over various mechanical processes, leading to improved productivity and reduced waste.Another noteworthy advancement in electromechanical engineering is the increasing use of renewable energy sources. As the global focus shifts towards sustainable development, the integration of renewable energy systemsinto electromechanical designs has become crucial. Engineers are now exploring innovative ways to harness solar, wind, and other renewable energy sources, converting them into useful mechanical energy.In addition, the rising demand for smart and connected devices has also influenced the evolution of electromechanical engineering. The integration of sensors, actuators, and communication technologies into electromechanical systems has led to the development of smart devices that can communicate with each other and respond to external stimuli. This has opened up a wide range of applications in areas such as smart homes, smart cities, and工业自动化.Moreover, the increasing complexity of electromechanical systems has led to the development of advanced simulation and modeling tools. These tools allow engineers to simulate and analyze the behavior of electromechanical systems under different conditions, enabling them to predict and optimize their performance. This has significantly reduced the time and cost associatedwith the design and development of electromechanical systems.In conclusion, the evolution of electromechanical engineering has been driven by the increasing demand for efficiency, reliability, and sustainability. Theintegration of automation, robotics, sensors, actuators, renewable energy sources, and smart technologies has led to the development of innovative solutions in various industries. As technology continues to advance, the role of electromechanical engineers will become even more crucial in driving the development of efficient and sustainable systems.。
专业英语unit13化学工程中的单元操作
Unit13Unit Operations in Chemical Engineering 第十三单元化学工程中的单元操作化学工程由不同顺序的步骤组成，这些步骤的原理与被操作的物料以及该特殊体系的其他特征无关。
在设计一个过程中，如果（研究）步骤得到认可，那么所用每一步骤可以分别进行研究。
有些步骤为化学反应，而其他步骤为物理变化。
化学工程的可变通性（versatility）源于将一复杂过程的分解为单个的物理步骤（叫做单元操作）和化学反应的实践。
化学工程中单元操作的概念基于这种哲学观点：各种不同顺序的步骤可以减少为简单的操作或反应。
不管所处理的物料如何，这些简单的操作或反应基本原理（fundamentals）是相同的。
这一原理，在美国化学工业发展期间先驱者来说是明显的，首先由 A.D.Lttle于1915年明确提出：任何化学过程，不管所进行的规模如何，均可分解为（be resolved into）一系列的相同的单元操作，如：粉碎、混合、加热、烘烤、吸收、压缩、沉淀、结晶、过滤、溶解、电解等等。
这些基本单元操作（的数目）为数不多，任何特殊的过程中包含其中的几种。
化学工程的复杂性来自于条件（温度、压力等等）的多样性，在这些条件下，单元操作以不同的过程进行，同时其复杂性来自于限制条件，如由反应物质的物化特征所规定的结构材料和设备的设计。
最初列出的单元操作，引用的是上述的十二种操作，不是所有的操作都可视为单元操作。
从那时起，确定了其他单元操作，过去确定的速度适中，但是近来速度加快。
流体流动、传热、蒸馏、润湿、气体吸收、沉降、分粒、搅拌以及离心得到了认可。
近年来，对新技术的不断理解以及古老但很少使用的分离技术的采用，引起了分离、处理操作或生产过程步骤上的数量不断增加，在多种操作中，这些操作步骤在使用时不要大的改变。
这就是“单元操作”这个术语的基础，此基础为我们提供了一系列的技术。
1.单元操作的分类（1）流体流动流体流动所涉及到的是确定任何流体的从一位置到另一位置的流动或输送的原理。
过控专业英语unit13
术语：gradient; motion;solid;electron;random motion;
• 对流
• 当宏观的流体颗粒流动穿过某特定的表面，比如某一控制 体积的边界，它会带来定量的热焓。像这种热焓的流动被 称为热对流或者简单对流。由于对流是一种宏观现象，因 此只有当力作用在微团或者液流上且该力能够克服摩擦力 并维持其运动时，这种传递现象才能发生。对流域流体力 学联系紧密。实际上，从热动力学上看，对流不被看成是 热量流动，而是被看成热焓的通量。实际上，很难将对流 和纯传导截然分开，因此，将二者概括起来称为对流时， 热对流的识别就很方便了。对流的例子，比方靠湍流漩涡 引起的热焓的传递或者由温暖的空气流过并离开普通换热 器引起的热焓的传递。 术语：enthalpy;the force of friction;turbulent flow; 短语：not…but;
•自然对流和强制对流 •用于产生流体中对流流动的力有两种。如果流动是由密度差引 起的浮力导致的，而且这种密度差是由流体微团的温度梯度引 起的，那么这种流动称为自然对流。空气通过散热器的流动就 是自然对流的一个例子。如果热流是由机械区分的作用（比如 泵或者搅拌器）引起的，流动是与密度梯度相独立的，那么称 这种对流为强制对流。热量流动到通过一个加热了的管子泵送 而来的流体上就是强制对流的一个例子。在同一流体中，两种 类型的力可能同时都很活跃，因此自然对流和强制对流是同时 发生的。 术语：natrual convection; forced convection;buoyancy force; density; pump; agitator;
Unit 13 Principles of Heat Transfer
Unit 13 热量传递原理
机电专业英语Lesson 2
Section II Text
Now people often talk about “feedback” as being an essential factor of the new in dustrial techniques, upon which is based an automatic self-regulating system and by virtue of which any deviation in the system from desired conditions can be det ected, measured , reported and corrected. When “feedback” is applied to the proc ess by which a large digital computer runs at the immense speed through a long s eries of sums, constantly rejecting the answers until it finds one to fit a complex set of facts that have been put to it, it is perhaps different in degree from what we have previously been accustomed to machines. But “feedback”, as such, is a famil iar mechanical conception. The old-fashioned steam engine was fitted with a cent rifugal governor, two balls on levers spinning round and round an upright shaft. I f the steam pressure rose and the engine started to go too fast, the increased spee d of the spinning governor caused it to rise up the vertical rod and shut down a va lve. This cut off some of the steam and thus the engine brought itself back to its p roper speed. The mechanization, which was introduced with the Industrial Revolution, beca use it was limited to individual processes, required the employment of human lab or to control each machine as well as to load and unload materials and transfer th em from one place to another. Only in a few instances were processes automatica lly linked together and was production organized as a continuous flow. End Topic Above 汉 Next
[新版]机械工程专业英语教程（第2版）[施平主编][翻译]_lesson12
![[新版]机械工程专业英语教程（第2版）[施平主编][翻译]_lesson12](https://img.taocdn.com/s3/m/62824efc18e8b8f67c1cfad6195f312b3169eb4d.png)
Spur GearsGears , defined as toothed members transmitting rotary motion from one shaft to another , are among the oldest devices and inventions of man . In about 2600 B.C. , the Chinese are known to have used a chariot incorporating a complex series of gears . Aristotle , in the fourth century B.C. , wrote of gears as if they were commonplace . In the fifteenth century A.D. , Leonardo da Vinci designed a multitude of devices incorporating many kinds of gears .齿轮，在最古老的设备和发明人中，被定义为通过轮齿将旋转运动从一根轴传递到另一根轴，大约在公元前2600年，中国人就知道用战车组成一系列复杂的齿轮系。
西元前四世纪，亚里士多德记述了齿轮就好像是他们司空见惯的一样。
在十五世纪，达芬奇设计了大量的包含各种各样齿轮的设备。
Among the various means of mechanical power transmission (including primarily gears , belts , and chains ) , gears are generally the most rugged and durable . Their power transmission efficiency is as high as 98 percent . On the other hand , gears are usually more costly than chains and belts . As would be expected , gear manufacturing costs increase sharply with increased precision -- as required for the combination of high speeds and heavy loads , and for low noise levels . ( Standard tolerances for various degrees of manufacturing precision have been established by the AGMA , American Gear Manufacturers Association. )在众多的机械传动方式中（包括齿轮传动，带传动，链传动），一般来说，齿轮是最经久耐用的，它的能量传递效率高达98%。
电子信息专业英语——13+unit+6+Electronic+Communication
Unit 6 Electronic Communications
4. Bandwidth and Information Capacity The two most significant limitations on the performance of a communications system are noise and bandwidth.
带宽与信息容量
Unit 6 Electronic Communications
In recent years, transistors and linear integrated circuits have simplified the design of electronic communications circuits, thus allowing for miniaturization, improved performance and reliability, and reduced overall costs.
(13) 国际电信联盟
(14)
(15)
Unit 6 Electronic Communications
3. Answer the following questions. (1) When and by whom was the first electronic communications system developed? (2) What is the first amplifying device for electrical signals? (3) What systems are included in modern electronic communications systems? (4) What’s the difference between analog signal, discrete signal and digital signal? (5) Could you state Hartley’s law and Shannon’s formula?
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机电专业英语
徐存善主编
We have following conclusions about the sinusoid: (1) If the input of a linear, time-invariant circuit is a sinusoid ，then the response is sinusoid of the same frequency. (2) Finding the magnitude and phase angle of a sinusoidal steady-state response can be accomplished with either real or complex sinusoids. (3) If the output of a sinusoidal circuit reaches its peak before the input, the circuit is a lead network.. Conversely, it is a lag network. (4) Using the concepts of phasor and impedance, sinusoidal circuits can be analyzed in the frequency domain in a manner analogous to resistive circuits by using the phasor versions of KCL, KVL, nodal analysis, mesh analysis and loop analysis.
apparent power(VA) reactive power VAR
real power(w)
Fig.13.3 power triangle
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Unit 13 Alternating current 交流电
机电专业英语
徐存善主编
Alternating current
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Alte
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机电专业英语
徐存善主编
An alternative current (AC) is an electrical current whose magnitude and direction vary cyclically, as opposed to direct [1] current, whose direction remains constant . 13.1 Alternating current Alternating currents are accompanied (or caused) by alternating voltages. In English the initialism AC is commonly and somewhat confusingly used for both. Step and impulse functions are useful in determining the responses of circuits when they are first turned on or when sudden or irregular changes occur in the input; this is called transient analysis. However, to see how a circuit responds to a regular or repetitive input—the steady-state analysis—the function that is by far the most useful is the sinusoid.
0 0
90 180
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360
ωt(s)
Fig.13.1 sine wave A sine wave, over one cycle (360。) is shown in Fig.13.1. The dashed line represents the root mean square (RMS) value at about 0.707 V peak. Where V peak is the peak voltage (unit: volt); ω is the angular frequency (unit: radians per second); T is the time to complete one cycle, and is called period (unit: second); The angular frequency ω is related to the physical frequency f which represents the number of oscillations per second (unit: hertz), by the equation: ω =2πf; t is the time (unit: second).
Square wave Triangle wave Sawtooth wave
one wave cycle
one wave cycle
one cycle
Fig.13.2 some common waveshapes (waveforms)
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机电专业英语
徐存善主编
They’re simply a few that are common enough to have been given distinct names. Even in circuits that are supposed to manifest “pure” sine, square, triangle, or sawtooth voltage/current waveforms, the real-life result is often a distorted version of the intended waveshape. Generally speaking, any waveshape bearing close resemblance to a perfect sine wave is termed sinusoidal, anything different being labeled as non-sinusoidal.
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机电专业英语
徐存善主编
Though electromechanical generators and many other physical phenomena naturally produce sine waves, this is not the only kind of alternating wave in existence. Other “waveforms” of AC are commonly produced within electronic circuitry. Here are but a few sample waveforms and their common designations in Fig.13.2.
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机电专业英语
徐存善主编
The sine[2] wave is the most common wave in AC and sometimes we refer to sine AC as AC in short . An AC voltage v can be described mathematically as a function of time by the following equation: v (t) =Vpeak sin (ωt)
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13.2 AC Electric power
机电专业英语
徐存善主编
We have previously defined power to be the product of voltage and current in the DC circuits. For the case that voltage and current are constants, the instantaneous power is equal to the average value of the power. The voltage and current are both sinusoids in AC circuits, however, the instantaneous power, which is still the product of voltage and current, changes with time and is not equal to the average power. In alternating current circuits, energy storage elements such as inductance and capacitance may result in periodic reversals of the direction of energy flow[ 3]. The portion of power flow that, averaged over a complete cycle of the AC waveform, results in net transfer of energy in one direction is known as real power (also referred to as active power). That portion of power flow due to stored energy that returns to the source in each cycle is known as reactive power.