外文翻译
Transformer
A Transformer is a device that change ac electric energy at one voltage level into ac electric energy at another voltage level through the action of a magnetic filed .It consists of two or more coils of wire wrapped a common ferromagnetic core. These coils are (usually) not directly connected. The only connection between the coils is the common magnetic flux present within the core.One of the transformer windings is connected to a source of ac electric power, and the second (and perhaps third) transformer winding supplies electric power to loads. The transformer winding connected to the power source is called the primary winding or input winding, and the winding connected to the loads is called the secondary winding or output winding. If there is a third winding on the transformer, it is called the tertiary winding.
Power transformers are constructed on one of two types of cores. One type of construction consists of a simple rectangular laminated piece of steel with the transformer windings wrapped around two sides of the rectangle. This type of construction is known as core form. The other type consists of a three-legged laminated core with the windings wrapped around the center leg. This type of construction is known as shell form. In either case, the
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外文翻译
core is constructed of thin laminations electrically isolated from each other in order to reduce eddy currents to a minimum.
Power transformers are given a variety of different names, depending on their use in power systems. A transformer connected to the output of a generator and used to step its voltage up to transmission levels is sometimes called a unit transformer. The transformer at the other end of the transmission line, which steps the voltage down from transmission levels to distribution levels, is called a substation transformer. Finally, the transformer that takes the distribution voltage and steps it down to the final voltage at which the power is actually used is called a distribution transformer. All these devices are essentially the same the only difference among them is their intended use.
In addition to the various power transformers, two special-purpose transformers are used with electric machinery and power systems. The first of these special transformers is a device specially designed to sample a high voltage and produce a low secondary voltage directly proportional to it, Such a transformer is called a potential transformer. A power transformer also produces a secondary voltage directly proportional to its primary voltage the difference between a potential transformer and a power transformer is that the potential transformer is designed to handle only a very small current. The second type of special transformer is a device
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外文翻译
designed to provide a secondary current much small than but directly proportional to its primary current. This device is called a current transformer
The ideal transformer without loss of energy, so have a 100% efficiency. In reality, the efficiency of power transformer reaches 98%, But small transformer loss will be more serious, and they may be less than 85% of efficiency. The energy loss from transformer in these phenomena: (in a coil of narrative, conductive are called "core"
The current through the winding resistance, thermal conductive (current generated when the heat to higher, the human body to feel energy losses caused to). And other kinds of loss, this loss not from the core transformer.
Eddy: the magnetic loss to generate electricity, iron loop back into heat energy and loss caused to the outside world. The core of don't cut into thin can reduce the loss.
Magnetism loss: all are not both senders coils magnetic field lines are receiving causes energy drain.
Hysteresis: core lagged effect of magnetic field changes that every cause loss of energy. This depends on the size of the loss of the core materials.
Alternating magnetic field strength loss: that wire, iron and near the electromagnetic force between the metal forming and
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外文翻译
changing the vibration and energy drain.
Magnetostrictive: the magnetic field that appear alternately core.If the core material susceptible to expansion effect of friction between the molecules, will lead to loss of energy.
Cooling equipment: large transformer with cooling fan with general of water pump, or the radiator. These devices have been using energy generally count the energy loss of transformer.
The overhead three phase power transmission line is the main energy corridor in a power system. One might assume that the circuit model would be trivial (ideal conductors), but three different phenomena produce effects that can not reasonably be ignored. In order of importance, they are the series voltages induced by the magnetic fields surrounding the conductors, the shunt displacement currents resulting from the electric fields between conductors，and the ohmic resistance of the conductor material. A forth，and minor, effect is the leakage conduction current that flows through contamination films on the insulators．
The overhead neutrals of a typical overhead power transmission line are electrically in contact with the tower and therefore grounded, They primarily exists to provide lightning shielding for the phase conductors and also to carry zero sequence and harmonic currents that help to maintain balanced sinusoidal voltages. They are usually steel or aluminum and are small
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外文翻译
(diameter about lcm)．The phase conductors are much larger (diameter about 5cm), and are typically stranded a1uminum surrounding a stranded steel cable (for increased tensile strength). sometimes more than one (a "bundle") comprise a phase．A11 are bare (no insulating covering) for heat dissipation reasons; the phase conductors are insulated from each other and the tower by suspension from insulator strings.
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外文翻译
变压器
变压器是通过磁场作用将交流电从某一电压等级转换至另一个电压级别的设备。它由两个或多个绕在铁氧体上的绕组构成。通常，绕组之间不直接相连，它们是通过铁芯内部的主磁通相连接的。变压器的一个绕组与交流电源连接，第二个绕组（也许第三个绕组）为负载提供电功率。与电源连接的绕组称为一个绕组或输入绕组。与负载连接的绕组称为二次绕组或输出绕组。如有第三个绕组，称为第三绕组。
变压器的铁芯分为两类。一类是由绕组缠绕在第一个简单的巨型港片叠成的铁芯两边而构成。此类结构的绕组称为铁芯式结构。铁芯不论是芯式还是框式，都是由薄薄的铁芯片做成的。铁芯片之间相互绝缘，以最大限度地降低涡流。
在电力系统中，根据不同的用途，电力变压器有许多种不同的名称。与发电机连接并将其电压提高到电网电压的变压器称为升压变压器。在输电线另一端，将电网电压降至配电电压的变压器称为降压变压器。最后，把电压降低到实际应用量级的变压器称为配电变压器。以上变压器的结构基本相同，唯一的区别在于各自的实际用途不同。
除了上述多种变压器之外，在电机与电力系统中还使用两种
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外文翻译
特殊用途的变压器。第一种专门设计的变压器室用来采样电压，并产生一个低的二次电压，该电压与所采样的电压成正比。此类变压器称为电压互感器。功率变压器中产生的二次侧的电压也与一次侧的电压成正比。但电压互感器与电力变压器的不同在于电压互感器设计为仅处理较小的电流。第二种专门设计的变压器设计成为用来提供比一次侧的电流要小的多的二次侧电流，且使二次侧的电流与一次侧的电流成比例。此类装置称为电流互感器。理想的变压器没有能量流失，所以拥有 100% 效率。在现实之中，大功率的变压器的效率可达 98%；但小型的变压器流失会较严重，而它们的效率可能低于 85%。变压器的能量流失可以来自这些现象： (在以下叙述中，线圈内的导电体一律称为“铁芯”)线圈的电阻：电流通过导电体时产生热能（电流要较高，发出的热人体才感觉的到），造成能量损失。和其他种类的流失不同，这种流失并不是来自变压器的铁芯。
涡流损：磁力使铁芯产生环回电流，导致能量化成热并流失至外界。把铁芯切成不相通的薄片可以减少这种流失。
磁力流失：所有未被输出方线圈接收的磁场线均会造成能量流失。
磁滞损：铁芯的滞后作用使每次磁场改变时造成能量流失。这种流失的大小取决于铁芯的原料。
力流失：交替的磁场使导线、铁芯与附近的金属之间的电磁力产生变化，结果形成振动和能量流失。
磁致伸缩：交替的磁场使铁芯出现伸缩。如果铁芯的原料容
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外文翻译
易受伸缩影响，分子之间的摩擦会导致能量流失。
冷却设备：大型的变压器一般配备冷却用的电风扇、油泵或注水的散热器。这些设备所使用的能量一般亦算作变压器的能量流失。
架空三相电力传输线在电力系统中是主要的能源通道。也许有人认为它的电路模型不值一提(理想导体)，但是我们没有理由忽视由三种不同的现象所产生的影响，按主要性依次为：导体周围磁场引起的串联电压，导体之间电场产生的旁路位移电流；导体材料本身的欧姆电阻。第四个也是较次要的影响为：在污染了的绝缘体表层流过的漏电流。
一个典型的三相电力传输线中的架空中性线和塔架在电气上是连接的，因此是接地的。中性线主要为各相导线提供避雷保护，也用来输送零序电流和谐波电流以便帮助保持三相正弦电压平衡。它一般是钢线或铝线，并且很细(直径约l cm)。而相线较租(直径约5cm)，一般为钢包铝绞线(为了增加抗拉张强度)。有时是由几根(一捆)组成一条相线。为了便于散热每根导体均为棵线(即没有绝缘护层)。每相导体之间有绝缘层，三条相线之间以及相线和杆塔之间通过悬挂绝缘子串来达到绝缘目的。
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中英文对照资料外文翻译文献 附件1：外文资料翻译译文 传感器新技术的发展 传感器是一种能将物理量、化学量、生物量等转换成电信号的器件。输出信号有不同形式，如电压、电流、频率、脉冲等，能满足信息传输、处理、记录、显示、控制要求，是自动检测系统和自动控制系统中不可缺少的元件。如果把计算机比作大脑，那么传感器则相当于五官，传感器能正确感受被测量并转换成相应输出量，对系统的质量起决定性作用。自动化程度越高，系统对传感器要求越高。在今天的信息时代里，信息产业包括信息采集、传输、处理三部分，即传感技术、通信技术、计算机技术。现代的计算机技术和通信技术由于超大规模集成电路的飞速发展，而已经充分发达后，不仅对传感器的精度、可靠性、响应速度、获取的信息量要求越来越高，还要求其成本低廉且使用方便。显然传统传感器因功能、特性、体积、成本等已难以满足而逐渐被淘汰。世界许多发达国家都在加快对传感器新技术的研究与开发，并且都已取得极大的突破。如今传感器新技术的发展，主要有以下几个方面： 利用物理现象、化学反应、生物效应作为传感器原理，所以研究发现新现象与新效应是传感器技术发展的重要工作，是研究开发新型传感器的基础。日本夏普公司利用超导技术研制成功高温超导磁性传感器，是传感器技术的重大突破，其灵敏度高，仅次于超导量子干涉器件。它的制造工艺远比超导量子干涉器件简单。可用于磁成像技术，有广泛推广价值。 利用抗体和抗原在电极表面上相遇复合时，会引起电极电位的变化，利用这一现象可制出免疫传感器。用这种抗体制成的免疫传感器可对某生物体内是否有这种抗原作检查。如用肝炎病毒抗体可检查某人是否患有肝炎，起到快速、准确作用。美国加州大学巳研制出这类传感器。 传感器材料是传感器技术的重要基础，由于材料科学进步，人们可制造出各种新型传感器。例如用高分子聚合物薄膜制成温度传感器；光导纤维能制成压力、流量、温度、位移等多种传感器；用陶瓷制成压力传感器。
外文文献原文+译文 原文 The study on the design of neuter clothing H ous e W Abstract Social and economic development, social thought, opening up and the progress of science and technology, men and women style presented the diversified pattern of neuter the fuzzy gender differences in style, from the beginning of non-mainstream des ign till n ow has develop ed i nt o on e of the mains t ream fas hi on d es ign style. Fashion brands have launched in recent years, the neutral flavor of fashion, neuter clothing market share of more and more, neutral fashion, with its broad group of sex leads the urban street fashion. Neutralization of free and open way of life style, gave people a comfortable and enjoyable. K ey words: Neut e r; Cl ot hing; Gender roles; Design 1 Introduction The beginning of the 20th century the rise of the feminist movement, make the neutral clothing as a kind of style into the line of sight of people. In the 90 s, the neutral clothing has used by each big brand clothing as one of the fashionable e lement s, s uc h a s dust coa t w i th a ne ut ral style, s ui ts, t-shirt s and j e ans have bec om e people like everyday clothes. Neuter clothing style is a simple, pure; reject all multifarious mincing, personalized style. As a special kind of clothing style, neuter clothing fashion has been intensified in the social life, so it is necessary for us to study the clothing neutralization phenomenon, to study its causes and the development of sociology. This article mainly from the sociological association as well as the relationship between men and women clothing and gender status in the society, which is based on analyzing the change of the study the social basis of the neutral clothing appear; Again from the social system, economic development, cultural trend and fashion designers to the influence of the neutral clothing style, etc., it is concluded that the neuter clothing phenomenon is the development of social consciousness, the sexual role transformation, the new clothing design trends are affecting the results.
变频器外文翻译文献 (文档含中英文对照即英文原文和中文翻译)
外文: Converter reference design (1)Converter Selection: Selection to determine the frequency converter when the following points: 1) The purpose of a variable frequency; constant pressure to control or constant current control. 2) the load converter types such as leaves or pump volume pumps, with special attention to load the performance curve, the performance curve of the decision of the ways and means. 3) the frequency converter and load matching Voltage match: a rated voltage converter with a rated voltage line with the load. Current matches: ordinary pump, the rated current inverter and motor rated current match. For special load such as deep-water pumps, and so on need to refer to the electrical performance parameters to determine the most current inverter current and Guozainengli. Torque match: in this case constant torque load or slow down when the device may have occurred. 4) the use of high-speed motor drive inverter, because of the high-speed motor, anti-small, high harmonics lead to increased output current value increases. So for high-speed motor inverter Selection, its capacity to be slightly larger than the ordinary motor selection. 5) If the frequency converter to a long cable run, this time to take measures to curb the long cable to the impact of capacitive coupling, inadequate efforts to avoid converter, so in this case, the drive to enlarge the capacity of a file or the converter Output installed output reactor. 6) For the application of some special occasions, such as high temperatures, high altitude, at this time would cause the down converter capacity, the drive to enlarge the capacity of a block.
译自<<科技英语>> 变压器 1. 介绍 要从远端发电厂送出电能，必须应用高压输电。因为最终的负荷，在一些点高电压必须降低。变压器能使电力系统各个部分运行在电压不同的等级。本文我们讨论的原则和电力变压器的应用。 2. 双绕组变压器 变压器的最简单形式包括两个磁通相互耦合的固定线圈。两个线圈之所以相互耦合，是因为它们连接着共同的磁通。 在电力应用中，使用层式铁芯变压器(本文中提到的)。变压器是高效率的，因为它没有旋转损失，因此在电压等级转换的过程中，能量损失比较少。典型的效率范围在92到99%，上限值适用于大功率变压器。 从交流电源流入电流的一侧被称为变压器的一次侧绕组或者是原边。它在铁圈中建立了磁通φ，它的幅值和方向都会发生周期性的变化。磁通连接的第二个绕组被称为变压器的二次侧绕组或者是副边。磁通是变化的；因此依据楞次定律，电磁感应在二次侧产生了电压。变压器在原边接收电能的同时也在向副边所带的负荷输送电能。这就是变压器的作用。 3. 变压器的工作原理 当二次侧电路开路是，即使原边被施以正弦电压V p，也是没有能量转移的。外加电压在一次侧绕组中产生一个小电流Iθ。这个空载电流有两项功能：（1）在铁芯中产生电磁通，该磁通在零和 φm之间做正弦变化，φm是铁芯磁通的最大值；（2）它的一个分量说明了铁芯中的涡流和磁滞损耗。这两种相关的损耗被称为铁芯损耗。 变压器空载电流Iθ一般大约只有满载电流的2%—5%。因为在空载时，原边绕组中的铁芯相当于一个很大的电抗，空载电流的相位大约将滞后于原边电压相位90o。显然可见电流分量I m= I0sinθ0，被称做励磁电流，它在相位上滞后于原边电压V P 90o。就是这个分量在铁芯中建立了磁通；因此磁通φ与I m同相。 第二个分量I e=I0sinθ0，与原边电压同相。这个电流分量向铁芯提供用于损耗的电流。两个相量的分量和代表空载电流，即 I0 = I m+ I e 应注意的是空载电流是畸变和非正弦形的。这种情况是非线性铁芯材料造成的。 如果假定变压器中没有其他的电能损耗一次侧的感应电动势E p和二次侧的感
中英文资料对照外文翻译 基于网络共享的无线传感网络设计 摘要：无线传感器网络是近年来的一种新兴发展技术，它在环境监测、农业和公众健康等方面有着广泛的应用。在发展中国家，无线传感器网络技术是一种常用的技术模型。由于无线传感网络的在线监测和高效率的网络传送，使其具有很大的发展前景，然而无线传感网络的发展仍然面临着很大的挑战。其主要挑战包括传感器的可携性、快速性。我们首先讨论了传感器网络的可行性然后描述在解决各种技术性挑战时传感器应产生的便携性。我们还讨论了关于孟加拉国和加利 尼亚州基于无线传感网络的水质的开发和监测。 关键词：无线传感网络、在线监测 1.简介 无线传感器网络，是计算机设备和传感器之间的桥梁，在公共卫生、环境和农业等领域发挥着巨大的作用。一个单一的设备应该有一个处理器，一个无线电和多个传感器。当这些设备在一个领域部署时，传感装置测量这一领域的特殊环境。然后将监测到的数据通过无线电进行传输，再由计算机进行数据分析。这样，无线传感器网络可以对环境中各种变化进行详细的观察。无线传感器网络是能够测量各种现象如在水中的污染物含量，水灌溉流量。比如，最近发生的污染涌流进中国松花江，而松花江又是饮用水的主要来源。通过测定水流量和速度，通过传感器对江水进行实时监测，就能够确定污染桶的数量和流动方向。 不幸的是，人们只是在资源相对丰富这个条件下做文章，无线传感器网络的潜力在很大程度上仍未开发，费用对无线传感器网络是几个主要障碍之一，阻止了其更广阔的发展前景。许多无线传感器网络组件正在趋于便宜化（例如有关计算能力的组件），而传感器本身仍是最昂贵的。正如在在文献[5]中所指出的，成功的技术依赖于
文献出处：A Dehghani. The application of digital printing in fashion design [J]. International Journal of Clothing Science and Technology, 2015, 16(2): 263-271. 原文 The application of digital printing in fashion design A Dehghani Abstract The appearance of digital printing for textiles printing provides a new train of thought, digital printing with the current textile fabric printing a variety of requirements of the market of printing technology, including high quality printing precision, high efficiency of printing on reaction time and the printing of the diverse demand, these advantages directly promoted the digital ink jet printing in the rapid development of textile fabric printing direction. In this paper, the design method of the digital printing design of different style and means of decoration and design method in the fabrics for summary, it is concluded that digital printing design cuttings in fabric printing, clothing apparel printing method and the application of the traditional fabric secondary design and decorative effect. Through the above research, digital printing and garment design and garment style between the relationships between the shapes, thereby further to bring into full play the advantages of
Constant pressure water supply frequency changer The transistor frequency changer not only overcame has formerly exchanged velocity modulation many shortcomings, moreover the velocity modulation performance might compare favorably with the direct current motor velocity modulation performance. The three-phase asynchronous motor has the service to be convenient, merit and so on price small advantage, power and rotational speed adapt breadth, its frequency conversion velocity modulation technology in the miniaturization, the low cost and the redundant reliable aspect holds the obvious superiority. To the end of the 80's, the alternating current machine frequency conversion velocity modulation technology rapidly develops into a mature technology, it will supply the alternating current machine the labor frequency alternating current supply to turn direct current after the diode rectification, again by component and so on IGBT or GTR module counter will turn the alternating current supply which the frequency might move, will drive the electrical machinery by this power source to move under the speed change condition, and automatic suitable strain load condition. After it changed in the traditional industry the electrical machinery to start only can by the rated power, decide the rotational speed the sole movement way, thus achieved the energy conservation goal. The modern frequency conversion velocity modulation technology applies in the electric power water pump water supply system. Because the frequency conversion velocity modulation has the velocity modula -tion the physical characteristics well, efficiency high, velocity modulation scope -wide, precision high, adjusting character curve smooth, may continual realize, the steady velocity modulation, the volume small, the maintenance simple is conven -ient, the automated level higher a series of prominent merits but time people's favor. When it applies especially in the air blower, the water pump and so on the large capacity load, may obtain the energy conservation effect which other velocity modulation ways is unable to compare. The frequency conversion velocity modulation system main equipment is provides the frequency conversion power source the frequency changer, the frequency changer may divide into exchange - direct current - to exchange the frequency changer and the exchange - exchan
附录 INTERNATIONAL STANDARD POWER TRANSFORMERS 1. Scope and service conditions 1.1 Scope This part of international Standard IEC60076 applies to three-phase and single-phase power transformers (including auto-transformers) with the exception certain categories of small and special transformers such as: -single-phase transformers with rated power less than 1 KV A and three-phase transformers less than 5 KV A; - instrument transformers; - transformers for static convertors; -traction transformers mounted on rolling stock; -starting transformers ; -testing transformers ; -welding transformers ; When standards do not exist for such categories of transformers, this part may still be applicable either as a whole or in part. 1.2 Service conditions This part gives detailed requirement for transformers for use under the following conditions: a)Altitude A height above sea-level not exceeding 1000 m . b) Temperature of ambient air not below - 25℃and not above +40℃.For water-cooled transformers , a temperature of cooling water at the inlet not exceeding +25℃. c) Wave shape of supply voltage A supply voltage of which the wave shape is approximately sinusoidal. NOTE This requirement is normally not critical in public supply systems but may
压力传感器 合理进行压力传感器的误差补偿是其应用的关键。压力传感器主要有偏移量误差、灵敏度误差、线性误差和滞后误差，本文将介绍这四种误差产生的机理和对测试结果的影响，同时将介绍为提高测量精度的压力标定方法以及应用实例。 目前市场上传感器种类丰富多样，这使得设计工程师可以选择系统所需的压力传感器。这些传感器既包括最基本的变换器，也包括更为复杂的带有片上电路的高集成度传感器。由于存在这些差异，设计工程师必须尽可能够补偿压力传感器的测量误差，这是保证传感器满足设计和应用要求的重要步骤。在某些情况下，补偿还能提高传感器在应用中的整体性能。 本文以摩托罗拉公司的压力传感器为例，所涉及的概念适用于各种压力传感器的设计应用。 摩托罗拉公司生产的主流压力传感器是一种单片压阻器件，该器件具有 3 类： 1.基本的或未加补偿标定； 2.有标定并进行温度补偿； 3.有标定、补偿和放大。 偏移量、范围标定以及温度补偿均可以通过薄膜电阻网络实现，这种薄膜电阻网络在封装过程中采用激光修正。 该传感器通常与微控制器结合使用，而微控制器的嵌入软件本身建立了传感器数学模型。微控制器读取了输出电压后，通过模数转换器的变换，该模型可以将电压量转换为压力测量值。传感器最简单的数学模型即为传递函数。该模型可在整个标定过程中进行优化，并且模型的成熟度将随标定点的增加而增加。 从计量学的角度看，测量误差具有相当严格的定义：它表征了测量压力与实际压力之间的差异。而通常无法直接得到实际压力，但可以通过采用适当的压力标准加以估计，计量人员通常采用那些精度比被测设备高出至少 10 倍的仪器作为测量标准。 由于未经标定的系统只能使用典型的灵敏度和偏移值将输出电压转换为压 力，测得的压力将产生如图 1 所示的误差。 这种未经标定的初始误差由以下几个部分组成： a.偏移量误差。由于在整个压力范围内垂直偏移保持恒定，因此变换器扩散和激光调节修正的变化将产生偏移量误差。 b.灵敏度误差，产生误差大小与压力成正比。如果设备的灵敏度高于典型值，灵敏度误差将是压力的递增函数（见图 1）。如果灵敏度低于典型值，那么灵敏度误差将是压力的递减函数。该误差的产生原因在于扩散过程的变化。
文献信息： 文献标题：Evolution of Fashion Design in the Era of High-Tech Culture （高科技文化时代服装设计的演变） 国外作者：Galina Mihaleva，C.Koh 文献出处：《International Scholarly and Scientific Research and Innovation》,2016,10(7):2447-2451 字数统计：英文2079单词，11462字符；中文3549汉字 外文文献： Evolution of Fashion Design in the Era of High-Tech Culture Abstract Fashion, like many other design fields, undergoes numerous evolutions throughout the ages. This paper aims to recognize and evaluate the significance of advance technology in fashion design and examine how it changes the role of modern fashion designers by modifying the creation process. It also touches on how modern culture is involved in such developments and how it affects fashion design in terms of conceptualizing and fabrication. By comparing case studies, existing fashion design examples and crafting method experimentations; we then spot patterns in which to predict the direction of future developments in the field. A breakdown on the elements of technology in fashion design helps us understand the driving force behind such a trend. The results from explorations in the paper have shown that there is an observed pattern of a distinct increase in interest and progress in the field of fashion technology, which leads to the birth of hybrid crafting methods. In conclusion, it is shown that as fashion technology continues to evolve, their role in clothing crafting becomes more prominent and grows far beyond the humble sewing machine. Keywords: Fashion design, functional aesthetics, smart textiles, 3D printing. INTRODUCTION It is common knowledge that the environment we live in greatly influences the
毕业设计--基于PLC的变频调速恒压供水系统（含外文翻 译） 山东科技大学学士学位论文摘要 摘要 本论文根据中国城市小区的供水要求，设计了一套基于PLC的变频调速恒压供水系统, 并利用组态软件开发良好的运行管理界面。变频恒压供水系统由可编程控制器、变频器、水泵机组、压力传感器、工控机等构成。 本系统包含三台水泵电机，它们组成变频循环运行方式。采用变频器实现对三相水泵电机的软启动和变频调速，运行切换采用“先启先停”的原则。压力传感器检测当前水压信号，送入PLC与设定值比较后进行PID运算，从而控制变频器的输出电压和频率，进而改变水泵电机的转速来改变供水量，最终保持管网压力稳定在设定值附近。通过工控机与PLC的连接，采用组态软件完成系统监控，实现了运行状态动态显示及数据、报警的查询。 关键词:变频调速，恒压供水，PLC，组态软件 山东科技大学学士学位论文 ABSTRACT ABSTRACT According to the requirement of China's urban water supply, this paper designs a set of water supply system of frequecey control of constant voltage based on PLC, and have developed good operation management interface using Supervision Control and Data Acquisition.The system is made up of PLC, transducer,units of pumps,pressure sensor and control machine and so on.
Circuit breaker 断路器 Compressed air circuit breaker is a mechanical switch equipment, can be i 空气压缩断路器是一种机械开关设备，能够在n normal and special conditions breaking current (such as short circuit cur 正常和特殊情况下开断电流（比如说短路电流）。 rent). For example, air circuit breaker, oil circuit breaker, interference circ 例如空气断路器、油断路器，干扰电路的导体uit conductor for the application of the safety and reliability of the circuit 干扰电路的导体因该安全可靠的应用于其中， breaker, current in arc from is usually divided into the following grades: a 电流断路器按灭弧远离通常被分为如下等级：ir switch circuit breaker, oil circuit breaker, less oil circuit breaker, compr 空气开关断路器、油断路器、少油断路器、压缩空essed air circuit breaker, a degaussing of isolating switch, six sulfur hexaf 气断路器、具有消磁性质的隔离开关、六氟luoride circuit breaker and vacuum breaker. Their parameters of voltage, 化硫断路器和真空断路器。他们的参数有电压等级、current, insulation level of breaking capacity, instantaneous voltage off ti 开断容量的电流、绝缘等级开断时间的瞬时电压恢复和me of recovery and a bombing. Breaker plate usually include: 1 the maxi 轰炸时间。断路器的铭牌通常包括： 1.最大可承
Basic knowledge of transducers A transducer is a device which converts the quantity being measured into an optical, mechanical, or-more commonly-electrical signal. The energy-conversion process that takes place is referred to as transduction. Transducers are classified according to the transduction principle involved and the form of the measured. Thus a resistance transducer for measuring displacement is classified as a resistance displacement transducer. Other classification examples are pressure bellows, force diaphragm, pressure flapper-nozzle, and so on. 1、Transducer Elements Although there are exception ,most transducers consist of a sensing element and a conversion or control element. For example, diaphragms,bellows,strain tubes and rings, bourdon tubes, and cantilevers are sensing elements which respond to changes in pressure or force and convert these physical quantities into a displacement. This displacement may then be used to change an electrical parameter such as voltage, resistance, capacitance, or inductance. Such combination of mechanical and electrical elements form electromechanical transducing devices or transducers. Similar combination can be made for other energy input such as thermal. Photo, magnetic and chemical,giving thermoelectric, photoelectric,electromaanetic, and electrochemical transducers respectively. 2、Transducer Sensitivity The relationship between the measured and the transducer output signal is usually obtained by calibration tests and is referred to as the transducer sensitivity K1= output-signal increment / measured increment . In practice, the transducer sensitivity is usually known, and, by measuring the output signal, the input quantity is determined from input= output-signal increment / K1. 3、Characteristics of an Ideal Transducer The high transducer should exhibit the following characteristics a) high fidelity-the transducer output waveform shape be a faithful reproduction of the measured; there should be minimum distortion. b) There should be minimum interference with the quantity being measured; the presence of the transducer should not alter the measured in any way. c) Size. The transducer must be capable of being placed exactly where it is needed.
英文翻译： The unique expression in fashion design Abstract: With the social progress and people's aesthetic awareness, clothing design requirements are constantly changing, not only beautiful, comfortable, personalized for different purposes, and more and more people started to pay attention the unique design of the clothing. unique expression of the clothing design has something in common, in common, there are three factors most typical one of the means of the use of the plastic arts; is to follow the basic rules of the plastic arts; the pursuit of art content and beauty of form harmony and unity. The face of increasingly fierce competition in society, from clothing unique starting to play to their strengths, so that the costume design perfected. Key words: aesthetic sense; costume design; uniqueness; expression Introduction With the rich substance of social development, improved quality of life, the pursuit of unique clothing is also more than plus strong, the face of the popularity and unity to the mass production of clothing has become a problem to be solved in order to fashion designers. An important design point, then become a unique expression of the costume design costume design costume design unique refers to the characteristics of the presentation of the representative from the clothing on the whole, it is unique content and form unity. China fashion design unique expression as a complete system of disciplines to study the ancient times to now there, but the uniqueness of expression in fashion design is not perfect, therefore, the uniqueness of this study fashion design to express Modern fashion design is of great significance. 1. The unique overview of clothing In short, The unique nature of the clothing is the clothing unique. In a broad sense refers to the presentation of the representative characteristics from the whole of the clothing works, it is one of the unique form and the objectivity of the unity of the unity of content, costume designer on the subjective aspect of creative and clothing subject matter difficult to find words to express, but it is not difficult to make us feel unique style. The unique nature of the clothing, but also refers to the values, artistic characteristics and inherent character of a nation, an era, a genre or a person's clothing in the content and format of the show out. The unique nature of the appearance of the mind, the pursuit of the realm of fashion design in the final analysis is unique in design and positioning, the unique expression of the costume design also reflects the designer's unique creative thinking and the pursuit of art also reflects the distinctive character.