科技文献中英文对照翻译

科技文献中英文摘要范文English:Nowadays, with the rapid advancement of technology, there has been increasing interest in applying artificial intelligence (AI) to various fields such as healthcare, finance, transportation, and more. AI has the potential to revolutionize these industries by improving efficiency, accuracy, and decision-making processes. In healthcare, AI tools can assist doctors in diagnosing diseases, predicting patient outcomes, and even personalizing treatment plans. In finance, AI algorithms can analyze market trends, predict stock prices, and detect fraudulent activities. In transportation, AI can optimize routes, reduce traffic congestion, and improve safety measures. Despite the great benefits AI can bring, there are also ethical and privacy concerns that need to be addressed. It is essential for policymakers, researchers, and industry professionals to work together to ensure responsible and ethical AI development.中文翻译:如今，随着科技的快速发展，人们越来越热衷于将人工智能（AI）应用于医疗保健、金融、交通等各个领域。

中国热门科技词汇科学发展观concept of scientific development全民科学文化素质scientific and cultural qualities of the entire people 发展科技scientific and technological advancement科教兴国revitalize China through science and education 农业技术agricultural technology[扩展]白色农业 white agriculture （microbiological agriculture and biological cell agriculture）超级杂交水稻super-hybrid rice技术下乡spreading the application of science and technology in rural areas节水农业water-saving agriculture立体农业3-D agriculture农产品加工及转化the processing and commercialization of agro-products 农业科技agro-science农作物良种seeds of high-quality crop农作物新品种选育the selection and breeding of new crops 生态农业environmental-friendly agriculture无土栽培soil -less cultivationBP机，传呼beeper, pager背投屏幕rear projection screen不明飞行物unidentified flying object （UFO）操作系统operating system产品科技含量technological element of a product创新innovation电话会议teleconference电话留言机answering machine对讲机talkie and walkie多媒体multimedia二期the second phase防抱死系统ABS （anti-lock braking system）孵化器incubator高产优质high yield and high quality高技术产业化apply high technology to production高科技板块high-tech sector高科技园high-tech park个人数字助理PDA （personal digital assistant）工业园区industrial park国家质量技术监督局the State Bureau of Quality and Technical Supervision 国家重点实验室national key laboratories火炬计划Torch Program （a plan to develop new and high technology）计算机中央处理器central processing unit（CPU）技术产权technology property right技术交底confide a technological secret to someone.技术密集产品technology-intensive product交叉学科interdisciplinary branch of science科技成果转化为生产力 transfer of scientific and technological achievements into productive forces科技含量technology content科技基础设施science and technology infrastructure科技是第一生产力Science and technology constitute a primary productive for ce科技体制改革reform of the science and technology management system科技与经济脱节science and technology are out of line from the economy科教兴国rejuvenate the country through science and education可持续发展战略strategy of sustainable development纳米nanometer三峡水利枢纽工程the key water control project at the Three Gorges on the Yangtze River物种起源origin of species新兴学科new branch of science研究成果research results在孵企业incubated enterprises自动取款机automatic teller machine （ATM）自然科学与社会科学的交叉融合integration of natural and social sciencesIT 信息技术[扩展]信息港info port信息高地information highland信息高速公路information superhighway信息革命information revolution信息含量information content信息化informationization信息技术处理ITA - Information Technology Agreement 信息检索information retri办公自动化OA （Office Automation）笔记本电脑laptop / notebook / portable computer 电脑病毒computer virus电脑犯罪computer crime电子管理e-management电子货币e-currency电子商务e-business; e-commerce电子商务认证e-business certification电子邮件E-mail非对称数字用户环路ADSL （Asymmetrical Digital Subscriber Loop）高速宽带互联网high-speed broadband networks公告板BBS （bulletin board system）光盘杂志CD-ROM magazine广域网WAN （wide area net word）汉字处理软件Chinese character processing software黑客hacker计算机2000年问题Y2K problem计算机辅助教育CAI -computer assisted instruction计算机辅助设计CAD-computer assisted design计算机合成制造CAM-computer assisted manufacturing计算机中央处理器CPU - central processing unit超文本传送协议hypertext transfer protocol （HTTP）界面interface金融电子化computerized financial services局域网LAN - local area network互联网服务提供商ISP （Internet Service Provider）全球移动通信系统（全球通）global system for mobile communications （GSM）刻录机CD burner宽带接入broadband access宽带网broadband networks内联网、局域网（计算机）Intranet垃圾邮件junk mail千年问题、千年虫millennium bug; Y2K bug 人工智能AI - artificial intelligence人机交互human - computer interaction人机交互human-computer interaction虚拟人visual human虚拟网virtual net虚拟网virtual net虚拟现实virtual reality虚拟银行virtual bank因特网服务提供商ISP- internet service provider万维网World Wide Web（WWW）应用软件internet applications域名domain在线on line掌上电脑palm computer政府上网工程Government Online Project只读存储器read-only-memory （ROM）智能感知技术perceptive technology智能终端intelligent terminal中文信息处理系统Chinese information processing system数码科技digital technology高保真Hi-Fi （High Fidelity）高清晰度电视high definition TV （HDTV）光谷optical valley光通讯optical communication蓝光光盘Blue -ray Disc数码港cyber port数字地球digital globe数字蜂窝移动通信digital cellular mobile telecommunications三维电影three-dimensional movie三维动画three-dimensional animation[详析] “蓝光光盘”利用蓝色的激光束来刻录数据。

13.3.3 C类放大器在C类功率放大器中，栅的偏压设成使晶体管在小于一半的时间内导通。

因此，漏极电流是由周期性的一串脉冲构成的。

传统上用正弦的上面部分来近似这些脉冲以便于进行直接分析②。

特别是我们假设漏极电流具有如下的形式：式中，偏置值I DC类似于线性放大器中的偏置电流，它对于C类放大器实际上是负值。

自然，整个漏极电流i D心总是为正或为零。

也就是说，漏极电流在晶体管导通时是一段正弦波，而在晶体管截止时为零。

我们继续假设晶体管在任何时候的工作情况都像是一个电流源(高输出阻抗)③。

由于我们仍然有一个高Q值的输出振荡回路，所以在负载两端的电压基本上保持为正弦，因此漏极电压和漏极电流如图13.4所示。

在以下的推导中，不必担心能否重复所有的这些细节。

正如我们将要看到的，我们如何设计这样的放大器与这些公式本身的含义有显著的不同，所以重点要放在所得到的一般结论而不是一些具体细节上。

我们从求解漏极电流不为零时总的导通角开始。

为了简化得到这一答案所需要的步骤，我们首先用余弦而不是正弦来重新写出漏极电流的表达式：显然，这样做没有任何改变，因为时间原点总是任选的。

在经过这样的修改之后，电流脉冲就如图13．5所示。

使电流等于零并求出总的导通角2中得到：我们现在可以计算平均漏极电流为:在用I DC的表达式替换后得到:我们将很快用这个表达式来推导效率作为导通角函数的公式。

我们需要的另一个量是传送到负载的功率的一般表达式。

正如与B类放大器一样由于高Q值的振荡回路而被简化，所以我们只需要计算傅里叶级数中的基波项：利用我们通过负载的基波电流的表达式，我们可以很容易地推导出最大输出电压摆幅的公式：上式允许我们求解用V DD表示的电流irf:峰值漏极电流为irf与偏置项的和为：上式可简化为:对于固定的输出电压，当脉冲宽度减小至零时，峰值漏极电流接近无穷大。

利用我们刚刚推导的公式可以很容易地计算出漏极效率为：当导通角缩小至零时，效率接近100％。

科技文献翻译Technology has transformed every aspect of our lives, from the way we communicate and work to how we shop and entertain ourselves. With the rapid advancement of technology, there is a growing demand for accurate translations of technology-related literature. This article aims to provide a translation of a technology paper consisting of 700 words.The paper titled "The Role of Artificial Intelligence in Autonomous Vehicles" explores the impact of AI in self-driving cars. Autonomous vehicles have gained significant attention in recent years due to their potential to revolutionize transportation. This paper discusses how AI technologies, such as deep learning and machine vision, have contributed to the development of autonomous vehicles.一项名为“人工智能在自动驾驶汽车中的角色”的研究探讨了AI在无人驾驶汽车中的影响。

在过去几年中，由于其改变出行方式的潜力，自动驾驶汽车引起了广泛关注。

Intelligent Power Supply英文With the rapid development of electronic technology, application field of electronic system is more and more extensive, electronic equipment, there are more and more people work with electronic equipment, life is increasingly close relationship. Any electronic equipment are inseparable from reliable power supply for power requirements, they more and more is also high. Electronic equipment miniaturized and low cost in the power of light and thin,small and efficient for development direction. The traditional transistors series adjustment manostat is continuous control linear manostat. This traditional manostat technology more mature, and there has been a large number of integrated linear manostat module, has the stable performance is good, output ripple voltage small, reliable operation, etc. But usually need are bulky and heavy industrial frequency transformer and bulk and weight are big filter.In the 1950s, NASA to miniaturization, light weight as the goal, for a rocket carrying the switch power development. In almost half a century of development process, switch power because of is small volume, light weight, high efficiency, wide range, voltage advantages in electric, control, computer, and many other areas of electronic equipment has been widely used. In the 1980s, a computer is made up of all of switch power supply, the first complete computer power generation. Throughout the 1990s, switching power supply in electronics,electrical equipment, into the rapid development. In addition, large scale integrated circuit technology, and the rapid development of switch power supply with a qualitative leap, raised high frequency power products of, miniaturization, modular tide.Power switch tube, PWM controller and high-frequency transformer is an indispensable part of the switch power supply. The traditional switch power supply is normally made by using high frequency power switch tube division and the pins, such as using PWM integrated controller UC3842 + MOSFET is domestic small power switch power supply, the design method of a more popularity.Since the 1970s, emerged in many function complete integrated control circuit, switch power supply circuit increasingly simplified, working frequency enhancesunceasingly, improving efficiency, and for power miniaturization provides the broad prospect. Three end off-line pulse width modulation monolithic integrated circuit TOP (Three switch Line) will Terminal Off with power switch MOSFET PWM controller one package together, has become the mainstream of switch power lC development. Adopt TOP switch lC design switch power, can make the circuitsimplified,volume further narrowing, cost also is decreased obviousiy.Monolithic switching power supply has the monolithic integrated, the minimalist peripheral circuit, best performance index, no work frequency transformer can constitute a significant advantage switching power supply, etc. American Pl (with) company in Power in the mid 1990s first launched the new high frequency switching Power supply chip, known as the "top switch Power", with low cost, simple circuit, higher efficiency. The first generation of products launched in 1994 represented TOP100/200 series, the second generation product is the TOPSwitch - debuted in 1997 П .The above products once appeared showed strong vitality and he greatly simplifies the design of 150W following switching power supply and the development of new products for the new job, also, high efficiency and low cost switch power supply promotion and popularization created good condition, which can be widely used in instrumentation, notebook computers, mobile phones, TV, VCD and DVD, perturbation VCR, mobile phone battery chargers, power amplifier and other fields, and form various miniaturization, density, on price can compete with the linear manostat AC/DC power transformation module.Switching power supply to integrated direction of future development will be the main trend, power density will more and more big, to process requirements will increasingly high. In semiconductor devices and magnetic materials, no new breakthrough technology progress before major might find it hard to achieve, technology innovation will focus on how to improve the efficiency and focus on reducing weight. Therefore, craft level will be in the position of power supply manufacturing higher in. In addition, the application of digital control IC is the future direction of the development of a switch power. This trust in DSP for speed and anti-interference technology unceasing enhancement. As for advanced control method, now the individual feels haven't seen practicability of the method appears particularly strong, perhaps with the popularity of digital control, and there are some new control theory into switching power supply.(1) The technology: with high frequency switching frequencies increase, switchconverter volume also decrease,power density has also been boosted, dynamic response improved. Small power DC - DC converter switch frequency will rise to MHz. But as the switch frequency unceasing enhancement, switch components and passive components loss increases, high-frequency parasitic parameters and high-frequency EMI and so on the new issues will also be caused．(2) Soft switching technologies: in order to improve the efficiency of non-linearity of various soft switch, commutation technical application and hygiene, representative of soft switch technology is passive and active soft switch technology, mainly including zero voltage switch/zero current switch (ZVS/ZCS) resonance, quasi resonant, zero voltage/zero current pulse width modulation technology (ZVS/ZCS - PWM) and zero voltage transition/zero current transition pulse width modulation (PWM) ZVT/ZCT - technical, etc. By means of soft switch technology can effectively reduce switch loss and switch stress, help converter transformation efficiency.(3) Power factor correction technology (IC simplifies PFC). At present mainly divided into IC simplifies PFC technology passive and active IC simplifies PFC technology using IC simplifies PFC technology two kinds big, IG simplifies PFC technology can improve AC - DC change device input power factor, reduce the harmonic pollution of power grid.(4) Modular technology. Modular technology can meet the needs of the distributed power system, enhance the system reliability.(5) Low output voltage technology. With the continuous development of semiconductor manufacturing technology, microprocessor and portable electronic devices work more and more low, this requires future DC - DG converter can provide low output voltage to adapt microprocessor and power supply requirement of portable electronic devicesPeople in switching power supply technical fields are edge developing related power electronics device, the side of frequency conversion technology, development of switch between mutual promotion push switch power supply with more than two year growth toward light, digital small, thin, low noise and high reliability, anti-interference direction. Switching power supply can be divided into the AC/DC and DC/DC two kinds big, also have AC/AC DC/AC as inverter DC/DC converter is now realize modular, and design technology and production process at home and abroad, are mature and standardization, and has approved by users, but the AC/DC modular, because of its own characteristics in the process of making modular, meetmore complex technology and craft manufacture problems. The following two types of switch power supply respectively on the structure and properties of this.Switching power supply is the development direction of high frequency, high reliability, low consumption, low noise, anti-jamming and modular. Because light switch power, small, thin key techniques are changed, so high overseas each big switch power supply manufacturer are devoted to the development of new high intelligent synchronous rectifier, especially the improvement of secondary devices of the device, and power loss of Zn ferrite (Mn) material? By increasing scientific and technological innovation, to enhance in high frequency and larger magnetic flux density (Bs) can get high magnetic under the miniaturization of, and capacitor is a key technology. SMT technology application makes switching power supply has made considerable progress, both sides in the circuit board to ensure that decorate components of switch power supply light, small, thin. The high frequency switching power supply of the traditional PWM must innovate switch technology, to realize the ZCS ZVS, soft switch technology has become the mainstream of switch power supply technical, and greatly improve the efficiency of switch power. For high reliability index, America's switch power producers, reduce by lowering operating current measures such as junction temperature of the device, in order to reduce stress the reliability of products made greatly increased．Modularity is of the general development of switch power supply trend can be modular power component distributed power system, can be designed to N + 1 redundant system, and realize the capacity expansion parallel. According to switch power running large noise this one defect, if separate the pursuit of high frequency noise will increase its with the partial resonance, and transform circuit technology, high frequency can be realized in theory and can reduce the noise, but part of the practical application of resonant conversion technology still have a technical problem, so in this area still need to carry out a lot of work, in order to make the technology to practional utilization.Power electronic technology unceasing innovation, switch power supply industry has broad prospects for development. To speed up the development of switch power industry in China, we must walk speed of technological innovation road, combination with Chinese characteristics in the joint development path, for the high-speed development of national economy to make the contribution.中文智能开关电源随着电子技术的高速发展，电子系统的应用领域越来越广泛，电子设备的种类也越来越多，电子设备与人们的工作、生活的关系口益密切。

Multi-texture-model for Water Extraction Based on Remote Sensing ImageHua WANG, Li PAN, Hong ZHENGSchool of Remote Sensing and Information & Engineering, Wuhan University 129 Luoyu Road,Wuhan 430079,P.R.ChinaSchool of Electronic Information, Wuhan University 129 Luoyu Road, Wuhan 430079,P.R.ChinaAbstract:In this paper, a multi-texture-model for water extraction based on remote sensing imagery is proposed. The model is applied to extract inland water (including wide river, lake and reservoir)from high-resolution panchromatic images. Firstly directional variance is used to find river regions, and then grain table is adopted to avoid noise including objects that have similar directional variance characteristic as water surfaces. The experiment result shows that the proposed method provides an effective way for water extraction.1. IntroductionThe recognition of water from remote sensing image has drawn considerable attention in recent yeas. A large number of publications about water extraction appeared and various approaches for water extraction have been proposed. Zhou developed a descriptive model for automatic extraction of water based on spectral characteristics[1]. Barton applied channel 4 for NOAA/AVHRR to extract water[2]. Du proposed a approach for water extraction from SPOT-5 based on decision tree algorithm[3]. Li recognized and monitored clear water from MODIS[4]. Wu extracted water from Quick Bird image and used active contour model to obtain accurate position of river bank[5]; In order to extract water from high-spatial remote sensing images, He used wavelet technique to expend the information and cleaned main noise of the images, and then presented multi-window linearity reserve technique to conserve linear water[6].Recently, most research work on water extraction was forced on automatic recognition of water from remote sensing images based on spectral characteristics. However, there are some disadvantages of these methods: (1) The resolution of image used for water extraction is low. The minimum size of recognizable object is depended on the spatial resolution of sensor. Therefore it is difficult to obtain accurate position of water boundary. (2) Due to the characteristic of water itself and the sensor applied, in certain channels the spectral features of different objects are equilibrated. The equilibration leads to the phenomena of “different objects same image” or“different images same object”, which results in noise objects included in extraction result.In this paper, a multi-texture-model for water extraction based on remote sensing is proposed. The model is applied to extract inland water (including wide river, lake and reservoir) fromhigh-resolution panchromatic image. Firstly directional variance is applied to find river regions, and then grain table is adopted to avoid noise including objects that have similar directional variance characteristic as water surfaces. The experiment result shows that the proposed method provides an effective way for water extraction.This paper is organized as follows. In Section 2, the directional variance model adopted is introduced. Then, fusion of proposed grain table model with directional variance model is discussed in Section 3.The experimental results of the proposed multi-texture-model and comparative studies with single models are given in Section 4. We conclude this paper in Section 5.2. Directional Variance ModelThe aim of our research is to extract water larger than 100m2from panchromatic images. As shown in Figure 2(a), the research objects can be divided into three classes: wide river, lake and reservoir, which all represent as region in high-resolution imageries. The objects of background can be divided into two classes: building and cropland, which also represent as region.In panchromatic imagery, wide river has a similar gray level to building and cropland, though the mean grayof lake and reservoir is much lower than the background objects. Conventional methods for water extraction based on spectral characteristics are not effective in the situation. In the meantime, water body defines homogeneous areas whereas building and cropland correspond to heterogeneous regions. Therefore, we take into account the homogeneity of the image to separate wide river, lake and reservoir from background instead. To characterize the difference of homogeneity between water body and the other types of areas, we use a textual operator: the directional variance.2.1. The Directional Variance OperatorThe operator is derived from those defined by Guerin & Maitre and Airault & Jamet[10]. As shown in Figure1, the directional variance consists in computing, for each pixel M of the image, the variance of the gray levels of the image on several direction of a circle whose center is M and radius is R. Then, the direction with the highest variance value is kept. Its direction defines the direction for which image is the most heterogeneous, locally. Its variance value is the directional variance value of the pixel M.2.2. Extraction of water based on directional varianceAccording to the definition of the operator, the minimum acreage of recognizable water body is depended on the length of radius R. We have chosen a length of 10 pixels for 1m resolution. The directional variances of the five typical training samples (wide river, lake, reservoir, building and cropland) have been computed and the statistical comparison is summarized in Table1. The overall average of water directional variance is lower than the objects of background.Nevertheless, the directional variance of cropland is similar to wide river with overlapping potion over 90%.Inhigh-resolution panchromatic imagery, details inside wide river, such as boat, wave, etc, are represented clearly which result in the heterogeneous of water. In the meantime, the textures of parts of building (for example, roof ) and cropland are rather fine. In a small window, these potions define homogeneous areas with similar directional variance as wide river. The result is improved if we chosen a length of 100 pixels. The statistical comparison is shown in Table2. If the length of radius is large enough, directional variance of building is higher than other objects obviously with no overlapping portion; the difference between cropland and wide river is increased while the overlapping potion is decreased. However, increasing the radius leads to two problems which are outlined as follow:1) The size of recognizable water body increases;therefore water which has small acreage (for example narrow river) can not be detected.2) The position of water bank is not accurate although the spatial resolution of imagery is rather high.Hence, in this paper, a multi-texture-model is presented and two texture models are fused to extract water from panchromatic images. Firstly, we chose a radius of 10 pixels to extract water based on directional variance; and then, grain table is adopted to avoid noise including parts of building and cropland that have similar directional variance characteristic as water surface.3. Multi-texture-modelIn high-resolution imagery, cropland and building represents structural characteristic. According to this characteristic, grain analysis is adopted for further research on the original extraction based on directional variance. The grain table histogram is able to represent structural characteristic of the research object, which can be applied to recognize many kinds of different objects [12].3.1. Extraction of water fused by grain tableThe grain table histograms of the five typical training samples (wide river, lake, reservoir, building and cropland) are computed and correlation coefficients between them are summarized in Table3. Correlation coefficients between water classes are over 85%, however, correlation coefficients between water classes and background classes are lower than 65%.Hence, we compare the correlation coefficients of regions in extraction image base on directional variance with three water samples and two background samples respectively. If the region has a higher correlation coefficient with background classes, it will be marked background and wiped off[13].4.Experimental ResultsWe run the algorithm on several high-resolution panchromatic images. In Figure2.(a), we have been considering an aerial photograph(6126×4800) of a region in Wuhan, China, the resolution of which is 1m,including building, cropland, wide river( Changjiang river), lake, reservoir and cropland. The results of extraction based on directional variance with radius of 10 pixels is displayed in Figure2.(b), and clearly, water has been detected completely, whereas parts of building and cropland are included as noise objects in the result. Water extraction using directional variance with radius of 100 pixels is displayed in Figure2.(c)with correctness over 95%, however, small lakes are missed and the position of bank is not as accurate as Figure2.(b). Finally, in Figure2.(d), the result of Figure2.(b) is fused by grain table analysis, so that the correctness and completeness of extraction are both over 90%.5. ConclusionsBased on textural analysis of water in high-resolution panchromatic imagery, a multi-texture-model is presented for water extraction.The experimental results proved that the approach is efficient for inland water (including wide river, lake and reservoir) extraction. As the complexity and diversity of water, the rate of recognition of our algorithm fluctuates. Furthermore, the method is supervised which needs a lot of human interference to obtain training samples. Therefore, there are problems to be solved in future:1) Our further work should be extensible to multispectral remote sensing images.2) To decrease human interference, old vector will be applied to obtain training samples instead. 6. AcknowledgmentsThe work was supported by the National Key Technology R&D Program of China under grant No.2006BAB10B01.根据遥感图象的多纹理模型相关的水抽取Hua WANG, Li PAN, Hong ZHENGSchool of Remote Sensing and Information & Engineering, Wuhan University 129 Luoyu Road,Wuhan 430079,P.R.ChinaSchool of Electronic Information, Wuhan University 129 Luoyu Road, Wuhan 430079,P.R.China文摘：在本文中，提议了一个多纹理模型为根据遥感成像的水提取。

本科毕业设计(论文)外文翻译姓名: 王文超学号： 200715010220专业: 电气工程及其自动化班级: 电气071502指导教师: 智泽英职称：副教授日期: 2011年6月12日电子信息工程学院The basics of Computer Numerical ControlWhile the specific intention and application for CNC machines vary from machine type toanother, all forms of CNC have common benefits. Though the thrust of this presentation is to teach you CNC usage, it helps to understand why these sophisticated machines have become so popular. Here are but a few of the more important benefits offered by CNC equipment.The first benefit offered by all forms of CNC machine tools is improved automation. The operator intervention related to producing workpieces can be reduced or eliminated. Many CNC machines can run unattended during their entire machining cycle, freeing the operator to do other tasks. This gives the CNC user several side benefits including reduced operator fatigue, fewer mistakes caused by human error, and consistent and predictable machining time for each workpiece. Since the machine will be running under program control, the skill level required of the a CNC operator (related to basic machining practice) is also reduced as compared to a machinist producing workpieces with conventional machine tools.The second major benefit of CNC technology is consistent and accurate workpieces. Today’s CNC machines boast almost unbelievable accuracy and repeatability specifications. This means that once a program is verified, two, ten, or one thousand identical workpieces can be easily produced with precision and consistency.A third benefit offered by most forms of CNC machine tools is flexibility. Since these machines are run from programs, running a different workpiece is almost as easy as loading a different program. Once a program has been verified and executed for one production run, it can be easily recalled the next time the workpiece is to be run. This leads to yet another benefit, fast change-overs. Since these machines are very easy to setup and run, and since programs can be easily loaded, they allow very short setup time. This is imperative with today’s Just-In-Time product requirements.1. Motion control-the heart of CNCThe most basic function of any CNC machine is automatic, precise, and consistent motion. Rather than applying completely mechanicaldevices to cause motion as is required on most conventional machine tools, CNC machines allow motion control in a revolutionary manner. All forms of CNC equipment have two or more directions of motion, called axes. These axes can be precisely and automatically positioned alongtheir lengths of travel. The two most common axis types are linear (driven along a straight path) and rotary (driven along a circular path).Instead of causing motion by turning cranks and handwheels as is required on conventional machine tools, CNC machines allow motions to be commanded through programmed commands. Generally speaking, the motion type (rapid, linear, and circular), the axes to move, the amount of motion and the motion rate (feedrate) are programmable with almost all CNC machine tools.Accurate positioning is accomplished by the operator counting the number of revolutions made on the handwheel plus the graduations on the dial. The drive motor is rotated a corresponding amount, which in turn drives the ball screw, causing linear motion of the axis. A feedback device confirms that the proper amount of ball screw revolutions has occurred.A CNC command executed within the control (commonly through a program) tells the drive motor to rotate a precise number of times. The rotation of the drive motor in turn rotates the ball screw. And the ball screw causes drives the linear axis. A feedback device at the opposite end of the ball screw allows the control to confirm that the commanded number of rotations has taken place.Though a rather crude analogy, the same basic linear motion can be found on a common table vise. As you rotate the vise crank, you rotate a lead screw that, in turn, drives the movable jaw on the vise. By comparison, a linear axis on a CNC machine tool is extremely precise. The number of revolutions of the axis drive motor precisely controls the amount of linear motion along the axis.How axis motion is commanded-understanding coordinate systems. It would be infeasible for the CNC user to cause axis motion by trying to tell each axis drive motor how many times to rotate in order to command a given linear motion amount. (This would be like having to figure out how many turns of the handle on a table vise will cause the movable jaw to move exactly one inch!) Instead, all CNC controls allow axis motion to be commanded in a much simpler and more logical way by utilizing some form of coordinate system. The two most popular coordinate systems used with CNC machines are the rectangular coordinate system and the polar coordinate system. By far, the move popular of these two is the rectangular coordinate system, and we’ll use it for all discussions made during this presentation.。

Human Geomatics in Urban Design—Two Case Studies在城市设计中的人类地理信息学——两个案例研究Małgorzata Hanzl1,*,Karol Dzik2,Paulina Kowalczyk2,Krystian Kwieciński2,Ewa Stankiewicz2and AgataŁ.Wierzbicka2Abstract:The mapping of different aspects of urban phenomena and their relation to thephysical cityscape has been greatly extended by the use of geomatics.The tradition to basereasoning on‗understanding the world‘dates from the time of Aristotle.The extensionplan for Barcelona(Eixample),developed by Cerdà,which opened the era of modern urbanplanning,was preceded by analyses of rich data,describing both detailed demographicissues and physical structures.The contemporary,postmodernist city planning continuesthis tradition,although a shift towards analyses of more human-related issues can beobserved,covering,inter alia,citizens‘perception,cultural differences and patterns ofhuman activities with regard to distinct social groups.The change towards a morehuman-related perspective and the inclusion of urban morphology analyses are directconsequences of this trend.The required data may be gathered within a crowd-sourcingparticipation process.According to communicative planning theory,communication withthe wider public is indispensable in order to achieve the best results,and can be realizedwith the use of sophisticated IT tools.Evidence-based reasoning may be supported byimages of significant aesthetic values,which inspire immediate reactions.Keywords:GIS;crowd-sourcing;mash-up;education;urban planning;urban analyses摘要：不同方面的城市现象及其与物理城市景观的关系映射经由地理信息学的使用已经大大扩展了。

科技类文章中英文对照范文带翻译印度首富百亿美元建4G网免费向全国提供India's richest man is rolling out a $20 billion mobile network that could bring lightning-fast Internet to hundreds of millions of people.印度首富正斥资200亿美元建设移动网络，或可使十亿人高速连接互联网。

Indian consumers are already celebrating the arrival of Mukesh Ambani's new Reliance Jio service, seizing on the billionaire's promise to deliver rock bottom prices and download speeds thatwill enable streaming video.印度消费者已经在庆祝穆克什•安巴尼新推出的瑞来斯Jio网络服务。

这位亿万富翁承诺，该网络会以最低价格提供满足流媒体使用的下载速度。

The 4G network, which reaches more than 80% of the country, officially went live Monday with a set of generous introductory offers.这个覆盖印度超过80%地区的4G网络于周一正式开通，同时慷慨附送试用套餐。

Indians will be able to use Jio for free until the end of 2021, and pay as little as 149 rupees $2.25 a month for data after that.印度人到今年年底都可免费使用Jio网络，之后的网费也只有每月149卢比2.25美金。

科技文1.单心室辅助人工心脏应用于实验动物山羊，存活11天又23小时。

在存活期间，动物心电图，中心静脉压，呼吸，体温等参数基本正常。

石泵分流量可调，驱动装置连续工作11天，性能稳定可靠。

动物死后的病理解剖表明，死亡的主要原因是肾动脉的广泛性血栓引起的急性肾功能衰竭。

A univentricular assistant artificial heart was applied to the experiment goat, which survived for 11 days and 23 hours. During the period of survival, the parameters such as E.C.G., central venous blood pressure, respiration and temperature appeared to be essentially normal. The necessary amount of blood flow was well regulated by the pump. The driving system worked continuously, smoothly and reliably for 11 days. Postmortem patho-anatomy revealed that the chief cause of the animal’s death was acute renal failure as a result of widespread multiple embolism of renal arteries.2. 中国已经成功地发射了第一颗试验通信卫星。

这颗卫星是由三级火箭推动的，一直运转正常。

它标志着我国运载工具和电子技术方面进入了一个新阶段。

The successful launching of China’s first experimental communication satellite, which was propelled by a three-stage rocket and has been in operation ever since, indicates that our nation has entered a new stage in the development of carrier rockets and electronics.3.石墨晶体结构遭到破坏时，总是碎化为微小尺寸的片状粉末。