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无线电力传输外文文献翻译
(含：英文原文及中文译文)
文献出处：Weaver, Bill. " Can't Touch This: Wireless power transmission."
26.3(2009).
英文原文
Can't touch this - wireless power transmission
William L. Weaver
A few years ago, a colleague and I participated in a field trip project organized by the college student group to study the West Orange at the Edison National Historic Site in . We visited with the public and participated in a laboratory set up inside a building to understand the development of incandescent light bulbs and film technology. However, what impressed me most was the two complex additional functions.
First, it is a research library equipped with all publications of the then US Patent Office. Representatives of scientists and engineers are concerned that marketable products may be useful in creating new technologies. The university is a great place to discover science and technology with it, but 's laboratory exists as a company. In the late 19th century, there was no internet connection, so the library took up the laboratory's information repository. Just like today, when the researchers needed information about chemical reactions, a mathematical formula or their most advanced engineering solution and consulted the current literature, it was only through paper at the time.
By simplifying the adoption of standards, this process is further simplified by the rapid adoption of standards. Since most of the tools and equipment can be developed locally, they can deploy their own standards and create the facility on a multi-acre campus.
One of these criteria is the method of distribution of power. The final known power supply for grid development is the famous bulb. The tools used in the early lab were a long axis of rotation like a rear-wheel drive automobile driveshaft made up of a universal cable shaft or a marine vessel. The propeller shaft disperses the potential energy of the entire plant in the form of mechanical energy generated by the boiler. A belt and a simple clutch system are connected to the line shaft and the strength of the lever is enhanced by using a surrounding shaft belt. Over time, the belt was worn out due to excessive friction. However, this technology provides a less complex power distribution method than earlier high-pressure steam and hydraulic systems.
Over time, as well as the development of electrical and electronic equipment, high-voltage power supplies and more distribution standards must be used in our production plants, offices and homes in the near future. In the , the electricity generated is 60 Hz and is eventually produced at a nominal voltage between 120, 240
and 480 volts. A typical power outlet is specified to accommodate 15 amps of current and is equipped with three familiar prongs, a vertical and U-shaped ground pin consisting of two paddles. Forward-looking retailers make pins of different shapes and orientations to prevent other incompatible devices from connecting. Unless there are not enough power outlets, plugs or extension cords, the standard three-hole power cord is a ubiquitous device to "plug in" the power distribution system.
With the continuous development of technology, mobile and handheld devices we currently have are booming, so battery companies will follow. Physically connecting these small devices to the grid will seriously affect their functionality. It is for this reason that they should exhaust their own power supplies or produce rechargeable batteries. manufacturers quickly develop their own industry standards, including "AA" and "C" units, to reduce the confusion that consumers may have when replacing batteries.
Although transistor radios and toy sensors were popular at the beginning of the year, single-use chemical batteries could not provide enough current for devices such as laptops, smart phones and personal entertainment games that have complicated computational requirements. Their rechargeable batteries are incorporated into the equipment and rarely need to be replaced by the user. These device manufacturers can choose how the battery is manufactured, such as size, battery life, and internal configuration capabilities of the device components. This feature of the battery has given manufacturers' industrial designers more rights to differentiate their products in style, look and feel.
However, the disadvantage of rechargeable batteries is that they eventually still need to be charged. We can easily connect to the power supply via an AC/DC power adapter. However, it is more difficult to connect the battery to the adapter or "charger" because each battery manufacturer is free to design the battery's shape and interface. what? In the lovely 100-year-old innovation after this, it did not change with the mode it should have.
A conspiracy theory may indicate that portable device manufacturers admit that battery chargers are a lucrative source of income. Similar bubble jet printer manufacturers rely on the consumption of ink in the device as a sales channel to make up for the difference between the selling price and the cost. Users pay $25 to $100 to replace the damaged or missing power adapter, which cancels out a service. The "real cost of freedom" in a planned or low-cost laptop phone. An innocent non-conspiratorial theory may be related to the 2000 (Y2K) problem. Programmers wouldn’t expect much trouble for this device made in a two-digit year to create for the future, and few portable device designers may expect to consume laptops, mobile phones, MP3 players, and digital cameras today. The number of people. These functions may eventually be provided by an independent "super smartphone", but at present, individual charger users are still inconvenient. Chargers also have similar, incompatible problems between devices, and users may cause exchanges to rise or lose devices. If you are using your fifth mobile phone, it is very likely that there will be four outdated chargers on your garage's work bench.
In February this year, the European Union Telecommunications Authority (CEPT)
and the subsequent European Union (EU) jointly authorized the establishment of the Publicis Group Special Mobile Association (GSMA), which was developed in 2012 as a standard for use by mobile phones. Micro USB interface charger specification. In addition to making the user more convenient, this specification has also been applied to the recycling of discarded adapters. Although it is not aimed at the standardization of adapters between different mobile devices, it seems to be a good start.
However, imagine that if the AC/DC adapter is completely eliminated. This is the future of wireless energy transfer. Nikola Tesla first published his utility in 1893. Inductively coupled transformers use wireless technology to replace an ordinary power adapter, correcting the drawbacks of the DC voltage required to charge the two inductive coils of an inductively coupled transformer supplied by an AC outlet. Unfortunately, as the distance between the transmitter and receiver increases, the inductance effect quickly diminishes and is often affected by interference. In other recent developments, Professor Malinsoor and his colleagues at the Massachusetts Institute of Technology recently developed inductive coupling coils that can be tuned to specific resonant frequencies to overcome these limitations. This improves the understanding of the coupling efficiency of the power supply and reduces the interference around other devices or between coils in other indifferent locations. It is called eCoupled technology.
While taking advantage of the high efficiency of the Witricity Resonance Sensing, the eCoupled system, including the sender and receiver, does not include the switching of a metal device or device of the RFID chip into sleep mode. The additional data services are robust and canonical communications, and will automatically power off when the battery is full. If widely adopted, wireless power transmission will be listed as a public service facility. Imagine eCoupled transmitters are simple when it comes to using new standards that are used to spur their own, usually using two main methods. To the new standard, there are usually two main methods used to promote its development. The first is a strong regulatory code. Second, inventing a technology that allows manufacturers to imitate and make it widely popular is powerful, but I prefer the latter's non-intervention method.
中文译文
不能触碰这个—无线电力传输
William L. Weaver
几年前, 一个同事和我参加在校大学生团体的组织的一个实地考察项目, 考察地位于新泽西州的爱迪生国家历史遗址的西橙。我们随公众一起参观, 并参观了设置于建筑物内的实验室, 了解了白炽灯灯泡和电影技术的发展。然而,令我最感动的是其中的两个复杂的附加功能。
首先,是配备了当时美国专利局的所有出版物的研究图书馆。科学家和工程师的代表关注到适销对路的产品可能会在创造新技术中有所用途。大学是随之而来的发现科学技术的伟大场所,但爱迪生的实验室却是作为一个企业而存在的。在19 世纪后期是没有互联网连接的, 因此,图书馆便担任起了实验室的信息存储库。就像今天,当研究人员所需要的信息是有关于化学反应、一个数学公式或他们最先进的工程解决方案而咨询目前的文献一样,只不过当时是通过纸张。
第二个令人印象深刻的事情是生产和加工设施的复杂性。创建工具, 使新
的工具催化技术的发展, 是爱迪生实验室的一个创新过程的早期代表性的例子。通过快速采用标准,进一步简化此过程。由于工具和设备大部分可以在本地发展, 即可以在数英亩大小的校园中部署自己的标准并创造该设施。
这种标准之一是权力分配的方法。最终已知的电网发展供电是著名的爱迪生灯泡, 早期的爱迪生实验室使用的工具是由一个通用线路轴组成的机器。组成一个类似于后轮驱动汽车传动轴的长旋转轴或像是一个海洋船只的螺旋桨轴, 使整个工厂的旋转的势能形式分散了锅炉产生的机械能。个别机器通过皮带和简单的离合器系统被连接到线路轴,通过使用周围的轴带来加强对杠杆的强度。随着时间的推移, 由于过多的摩擦,皮带便穿了出来。但这种技术提供了一个相比早期高压蒸汽和液压系统来说不太复杂的动力分配方法。
随着时间的推移, 以及电器及电子设备的开发,在不久之后我们的生产厂房、办公室和家庭中必须采用高压电源和更多的分配标准。在美国, 产生的电力是60赫兹,并最终产生在120, 240和480伏特之间的标准额定电压。典型的电源插座被规定制造为容纳15安培电流和配有熟悉的三个插脚, 两个桨组成的垂直的和U 型接地的插脚。具有前瞻性的零售商制造不同形状和取向标准的插脚,以防止其他不兼容的设备连接。除非没有足够的电源插座、插头或延长线带,标准的三孔电源线是一种普遍存在的设备来“塞“进配电系统。
随着技术的不断发展,目前我们拥有的移动和手持设备正在蓬勃发展,因此电池企业随之产生。将这些小型设备物理上连接到电网,将严重影响他们的功能。正是因为这个原因,他们应把自己的自带电源一次性耗尽或生产充电电池。电池制造商们快速的开发出自己的行业标准, 其中包括“AA“和“C”型单元,以减轻消费者更换电池时可能产生的混淆。
虽然年初晶体管收音机、玩具用传感器流行,但一次性使用的化学电池不能为如笔记本电脑、智能手机和个人娱乐游戏机这些拥有复杂的计算要求的设备提供其所需的充足电流。他们可充电的电池被收纳入设备的内部, 很少需要用户自行更换。这使设备制造商可以据此选择电池如何制造,例如大小,电池寿命和设备组件的内部配置功能。电池的这一特性, 授予了制造商的工业设计师们在造型、外观和感觉上区分他们产品的更多权利。
但充电电池的缺点是,他们最终依然需要充电。我们很容易即可通过一个交直流电源适配器连接到电源。然而较难是电池怎样连接到适配器或“充电器” ,因为每个电池制造商都可以自由地设计电池的外形和接口。什么?在此之后的可爱的百年创新中,其并未随着应有的模式有所改变。
一个阴谋理论也许可以说明,便携式设备制造商承认,电池充电器是一个利润丰厚的收入渠道。类似气泡喷墨打印机制造商依赖于油墨在设备中的消耗作为销售渠道,以弥补销售价低于成本的差额, 用户支付25美元至100美元更换损坏或丢失的电源适配器, 这样便抵消了一个服务计划或低成本的笔记本电脑手机中的“自由的真实成本” 。一个无辜的非阴谋理论可能是与2000年(Y2K )问题相关。程序员预想不到这个制造于两位数年份的设备会为未来制造多大的麻烦, 同时也很少有便携式设备设计者可能预料到如今同时携带笔记本电脑、移动电话、MP3播放器和数字摄像机的消费者的数量。这些功能最终可能会由一个独立的" 超级智能手机" 来提供,但是,目前,个别的充电器使用者还是很不方便。充电器也有类似的,设备之间不兼容的问题,用户可能会导致交换升级或丢失设备。如果你正在使用你的第五部手机,很有可能在你的车库的工作台上会有四个已过时的充电器。
今年2月,由欧洲联盟电信局(CEPT )和随后的欧洲联盟(EU )共同授权同意设立阳狮集团Speciale 移动协会(GSMA ) , 这是一个在2012年开发的标准的, 供移动电话使用的微型USB 接口充电器规范。除了使用户更加的便利,这项规范也被应用到被丢弃的适配器的回收浪潮中。虽然不是针对不同的移动设备之间的转接器的标准化问题, 但它看起来是一个好的开始。
但是,试想一下,如果将AC/DC适配器完全可以消除。这是无线能量转移的未来,尼古拉·特斯拉于1893年首先将其效用发表出来。电感耦合变压器利用无线技术可替换普通电源适配器, 纠正了电感耦合变压器的两个感应线圈充电所需的直流电压由交流电源插座提供电力的弊端。不幸的是, 随着发射机和接收机之间的距离增加电感效应迅速减弱,经常受到干扰的影响。在最近的其他事态发展中,马林索尔教授和他的同事们最近在麻省理工学院, 制订可以使用调到特定的共振频率的电感耦合线圈,以克服这些限制。这提高了电源的耦合效率,并减少了其他无关紧要的位于设备周围或线圈之间的干扰。麻省理工学院称之为其发展的“ Witricity ” ,它正在由富尔顿创新Ada MI商业化,并被称为eCoupled 技术。
同时利用Witricity 谐振感应的高效率,包括发件人和接收器的eCoupled 系统不包含无线射频识别芯片的金属设备或装置的开关后进入睡眠模式。附加的数据服务健全和规范的通信,而且会在电池充满后自动断电。如果被广泛采纳,无线电力传输将会被列为公共服务设施。想象一下, eCoupled 发射机简单当谈到有用来鞭策自己, 通常采用两种主要方法的新标准。说到新的标准,通常有两个主要方法用于推动其发展。首先是有力的法规规范。其次, 发明一种技术使得制造商竞相模仿, 使之广泛流行两种方法都强大, 但我更喜欢后者那种不干预的方式。
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PLC控制下的电梯系统 由继电器组成的顺序控制系统是最早的一种实现电梯控制的方法。但是，进入九十年代，随着科学技术的发展和计算机技术的广泛应用，人们对电梯的安全性、可靠性的要求越来越高，继电器控制的弱点就越来越明显。 电梯继电器控制系统故障率高，大大降低了电梯的可靠性和安全性，经常造成停梯，给乘用人员带来不便和惊忧。且电梯一旦发生冲顶或蹲底，不但会造成电梯机械部件损坏，还可能出现人身事故。 可编程序控制器(PLC)最早是根据顺序逻辑控制的需要而发展起来的，是专门为工业环境应用而设计的数字运算操作的电子装置。鉴于其种种优点，目前，电梯的继电器控制方式己逐渐被PLC控制所代替。同时，由于电机交流变频调速技术的发展，电梯的拖动方式己由原来直流调速逐渐过渡到了交流变频调速。因此，PLC控制技术加变频调速技术己成为现代电梯行业的一个热点。 1. PLC控制电梯的优点 (1)在电梯控制中采用了PLC，用软件实现对电梯运行的自动控制，可靠性大大提高。 (2)去掉了选层器及大部分继电器，控制系统结构简单，外部线路简化。 (3)PLC可实现各种复杂的控制系统，方便地增加或改变控制功能。 (4) PLC可进行故障自动检测与报警显示，提高运行安全性，并便于检修。 (5)用于群控调配和管理，并提高电梯运行效率。 (6)更改控制方案时不需改动硬件接线。 2.电梯变频调速控制的特点 随着电力电子技术、微电子技术和计算机控制技术的飞速发展，交流变频调速技术的发展也十分迅速。电动机交流变频调速技术是当今节电、改善工艺流程以提高产品质量和改善环境、推动技术进步的一种主要手段。变频调速以其优异的调速性能和起制动平稳性能、高效率、高功率因数和节电效果，广泛的适用范围及其它许多优点而被国内外公认为最有发展前途的调速方式 交流变频调速电梯的特点 ⑴能源消耗低 ⑵电路负载低，所需紧急供电装置小 在加速阶段，所需起动电流小于2.5倍的额定电流。且起动电流峰值时间短。由于起动电流大幅度减小，故功耗和供电缆线直径可减小很多。所需的紧急供电
Gee Journal 31.4457-465457?1993 (Dec) by Kluwer Academic Publishers Ecotoufism in the Small Island Caribbean Weave~ David B., Prof. Dl:, UniversiO, of Regina, Luther College, Regina, Saskatchewan $4S OA2, Canada ABSTRACT: Ecotourism-related strategies can serve to enhance the tourism industries of small Caribbean islands, which are presently dominated by a 3S (sea, sand, sun) product. In the first place, the principles of Alternative Tourism can be applied to 3S tourism in order to minimize negative environmental impacts. Secondly, diversionary ecotourism opportunities can be promoted to diversify the tourism product, thus providing a nature-oriented alternative to resort-based tourists. Thirdly, regional ecotourism, catering to ecotourists, can be fostered in mountainous interiors, peripheral islands, undeveloped coastlines, rural agricultural areas and in offshore reefs. A fourth strategy, exemplified by Dominica, entails a comprehensive ecotourism approach for destinations in which 3S tourism is undesired or unsuited. Introdactien The concept of ecotourism has attracted a considerable amount of interest among both academics and non-academics since the term was first introduced in the mid-1980s (see for example Boo t990; Goriup 1991; Lindberg 1991; Nelson, Butler and Wall 1993; Whelan 1991; Ziffer 1989). In a frequently cited definition, Ceballos-Lascurain (1988) characterizes ecotourism as Tourism that involves travelling to relatively undisturbed or uncontaminated natural areas with the specific object of studying, admiring and enjoying the scenery and its wild plants and animals, as well as any existing cultural aspects (both past and present) found in these areas. While this definition is useful in stressing the environmental orientation of ecotourism, it is clear that the term has also come to be associated with a range o f characteristics which collectively define an "alternative tourism" (AT) paradigm (Dernoi 1981; Krippendorf 1987; Singh, Theuns and Go 1989). This paradigm has emerged as an alternative to "conventional mass tourism" (CMT), which has been criticized as an often inappropriate form of tourism, especially for smaller destinations. CMT characteristics, outlined and contrasted in Tab 1 with the AT model, tend to appear during the middle and later stages of a destination's cycle of evolution (Butler 1980; Christaller 1963; Stansfield 1978). With respect to accommodations, attractions, market and economic impact, the argument can be made that ecotourism and AT are merely other names for the early "exploration" stage of the resort cycle, when relatively unspoiled areas are opened up to further tourist incursions by a few pioneer travellers. However, as pointed out by Weaver (1991), what distinguishes this "circumstantial" AT from "deliberate" AT is the lack of regulations and policies which attempt to ensure that the activity is maintained at environmentally, economically and socially sustainable levels. "Deliberate" ecotourism, the subject of this paper, is therefore very" much associated with intentions of identifying and working within the carrying capacities of a particular area, and o f discouraging the emergence of a CM T product where it is deeme d to be undesirable or inappropriate. The recent proliferation of ecotourism case studies, based largely in the underdeveloped world, is not surprising in light of deliberate ecotourism's status as the fastest growing form o f tourism (Whelan 1991). For example, Dearden (1989) and Zurick (1992) examined the p h e n o m e n o n of mountain trekking in Nepal and northern Thailand respectively, while Boo (1990), and Fennell and
附录1 RURAL FINANCE: MAINSTREAMING INFORMAL FINANCIAL INSTITUTIONS By Hans Dieter Seibel Abstract Informal financial institutions (IFIs), among them the ubiquitous rotating savings and credit associations, are of ancient origin. Owned and self-managed by local people, poor and non-poor, they are self-help organizations which mobilize their own resources, cover their costs and finance their growth from their profits. With the expansion of the money economy, they have spread into new areas and grown in numbers, size and diversity; but ultimately, most have remained restricted in size, outreach and duration. Are they best left alone, or should they be helped to upgrade their operations and be integrated into the wider financial market? Under conducive policy conditions, some have spontaneously taken the opportunity of evolving into semiformal or formal microfinance institutions (MFIs). This has usually yielded great benefits in terms of financial deepening, sustainability and outreach. Donors may build on these indigenous foundations and provide support for various options of institutional development, among them: incentives-driven mainstreaming through networking; encouraging the establishment of new IFIs in areas devoid of financial services; linking IFIs/MFIs to banks; strengthening Non-Governmental Organizations (NGOs) as promoters of good practices; and, in a nonrepressive policy environment, promoting appropriate legal forms, prudential regulation and delegated supervision. Key words: Microfinance, microcredit, microsavings。 1. informal finance, self-help groups In March 1967, on one of my first field trips in Liberia, I had the opportunity to observe a group of a dozen Mano peasants cutting trees in a field belonging to one of them. Before they started their work, they placed hoe-shaped masks in a small circle, chanted words and turned into animals. One turned into a lion, another one into a bush hog, and so on, and they continued to imitate those animals throughout the whole day, as they worked hard on their land. I realized I was onto something serious, and at the end of the day, when they had put the masks into a bag and changed back into humans,
伺服电机 1. 伺服电机的定义 伺服电动机又称执行电动机，在自动控制系统中，用作执行元件，把所收到的电信号转换成电动机轴上的角位移或角速度输出。分为直流和交流伺服电动机两大类，其主要特点是，当信号电压为零时无自转现象，转速随着转矩的增加而匀速下降。伺服电机在伺服系统中控制机械元件运转的发动机. 是一种补助马达间接变速装置。伺服电机可使控制速度, 位置精度非常准确。将电压信号转化为转矩和转速以驱动控制对象。转子转速受输入信号控制，并能快速反应，在自动控制系统中作执行元件，且具有机电时间常数小、线性度高、始动电压低等特点。 2. 伺服电机工作原理 1.伺服主要靠脉冲来定位，基本上可以这样理解，伺服电机接收到1 个脉冲，就会旋转1 个脉冲对应的角度，从而实现位移，因为，伺服电机本身具备发出脉冲的功能，所以伺服电机每旋转一个角度，都会发出对应数量的脉冲，这样，和伺服电机接受的脉冲形成了呼应，或者叫闭环，如此一来，系统就会知道发了多少脉冲给伺服电机，同时又收了多少脉冲回来，这样，就能够很精确的控制电机的转动，从而实现精确的定位，可以达到0.001mm有刷电机成本低，结构简单，启动转矩大，调速范围宽，控制容易，需要维护，但维护方便（换碳刷），产生电磁干扰，对环境有要求。无刷电机体积小，重量轻，出力大，响应快，速度高，惯量小，转动平滑，力矩稳定。控制复杂，容易实现智能化，其电子换相方式灵活，可以方波换相或正弦波换相。电机免维护，效率很高，运行温度低，电磁辐射很小，长寿命，可用于各种环境。 2. 交流伺服电机也是无刷电机，分为同步和异步电机，目前运动控制中一般都用同步电机，它的功率范围大，可以做到很大的功率。大惯量，最高转动速度低，且随着功率增大而快速降低。因而适合做低速平稳运行的应用。 3. 永磁交流伺服电动机简介 20 世纪80 年代以来，随着集成电路、电力电子技术和交流可变速驱动技术的发展，永磁交流伺服驱动技术有了突出的发展，各国著名电气厂商相继推出各自的交流伺服电动机和伺服驱动器系列产品并不断完善和更新。交流伺服系统已成为当代高性能伺服系统的主要发展方向，使原来的直流伺服面临被淘汰的危机。90 年代以后，世界各国已经商品化了的交流伺服系统是采用全数字控制的正弦
生态旅游对环境的影响（节选） 原文来源：Environment Impacts of Ecotourism;Edited by Ralf Buckley International Centre for Ecotourism Research,Griffith University,Australia CAIB Publishing;Oct,2008 生态旅游由于其实际或潜在的积极影响受到社会和保护区以及公司和消费者广泛吹捧。例如，在讨论进入保护区方面，旅游说客和生态旅游经营者宣称他们不仅将会采取措施师环境影响减到最小,而且生态旅游还会产生利益。然而,保护区也为旅游业提供了非常重要的好处。 每年被人类消耗或污染的自然资源有很多。人类生存需要饮用水，可呼吸的空气和可用的生物多样性。自然生态系统是每个这些领域的主要的蓄水池。生态系统由于人类活动已被不同程度地广泛地修改了。近原始的荒野地区和其他小改造的地区的环境正在不断减少，像城市中心，垃圾堆放场，矿场和单一种植区几乎完全修改的环境在继续扩大。有很多没有完全修改而又很重要的地方，如农村住宅，布罗德埃克牧区和被采伐的原始森林在最少修改的地区也继续扩大。为制止和扭转这些趋势，只在人类的社会结构和人类行为发生大规模和深远的变化时才能成为可能。然而，如果在短期内没有这种变化，规模更大的混乱将逼近人类。 关于可持续能力和关乎人类生存的任何长期策略唯一最重要的组分，能够使世界各种各样的生态系统的代表性区域保持在一个合理的原封不动的和功能的状态。当然，这是保护区全局系统的主要目标，包括世界遗产地区、生物圈储备、国家公园和其他保护区域。然而，这些公园还不能独自地防止生物多样性持续损失：首先，因为他们是太小和不充分地代表性的；第二，因为他们不充分地被保护。目前，有公开和私有土地其他地区在被保护区系统之外的，它们对保护生物多样性和空气和水的质量有很大贡献。它们包括：像极地，高山，沙漠和海洋生态系一样很少人的地方；那些为木材和家畜产品使用的但其中很少使用牧场保留其原有的性质功能和生物多样性的森林地和牧场；人类的生活方式没有介入对自然环境的密集的修改的部族和社区土地。然后，随着人口和资源消耗量的继续增长，所有这些未保护的区域却受到越来越多的开发和修改，例如采伐，农业清除和类似的冲击加速。特别是，其中一些区域涉及保护和储备，而且逐渐增长的人口压力正在导致土地清除和移民直到储备界限，有时会在保护的过程中出现侵犯。在被保护区界限不是明确界定或没有发现的地区，这样侵犯也许一般包括偷猎，非法收获，小规模移民和时而的军事演习。然而，甚而在国家公园界限已建立和强制执行的区域，侵犯可能仍然发生。有时，相关的立法也许允许发展某些类在公园界限之外的可能在保护区的周长附近增加杂草、病原生物、野生动物、水污染和火来源的压力，并且这些能不再人类进一步的干涉下在保护区里得到传播。 因此，代表性的生态系统的保护不仅能够通过增加保护区财产，改进现存储备的有效保护率，而且通过减少对储备区以外土地的修改得到改进，以便改进它的保护价值。 用纯粹财政术语来说，以现在的市场价购买高保护价值所有剩余的区域，在更加富有的政府和公司看来是在世界范围内的，并且宣称他们作为保护区。然而，由于许多政治原因，这是不太可能发生得。许多保护区管理代办处没有足够的金钱来管理他们现有的财产，更不用说发展它。全世界国家公园和相似的储备总面积继续慢慢地增长，并且在最近几年里给保护区的管理代办处的一些资助增加显著。然而，在全球范围内，公共的保护区越来越资金短缺。同时，他们不断地受到人类的压力，这种压力同时来自于从在它们的边界之外的压力和游客的人数和期望增长的压力。结果，只有最大和最远的保
abstract Power electronic technology is divided into power electronics manufacturing technology and variable flow technology (rectifier, inverter, chopper, inverter, a disguised form, etc.) two branches. Has now become indispensable to modern electrical engineering and automation major a professional basic course, occupies an important position in cultivating the professional talents. Power Electronics (Power Electronics) this name is in the 1960 s. In 1974, the United States W.N ewell with an inverted triangle (pictured) for power electronics are described, that it is by electricity, electronics and control theory of the three disciplines cross. This view is widely accepted around the world. \"Power electronics\" and \"power electronic technology\" is respectively from the Angle of the two different academic and engineering technology to call. It is generally believed that the birth of the power electronic technology is a 1957 American ge company developed the first symbol of thyristor, power electronic technology and is based on the concept of the thyristor and thyratron converter technology development and establishment of the. Previously have been used in power transformation of the electronic technology, so the thyristor appeared in front of the period can be referred to as the power electronic technology of prehistoric or dawn. In the late 70 s at the door may be shut off thyristor (decision), Power bipolar transistor (BJT), electric Power field effect tube (Power MOSFET) type of all control device development at full speed (all control device is characterized by polar opposite gate or both the base control can make its opening to shut off). Make the power electronic technology has taken on a entirely newlook entered a new stage of development. In the late 80 s, with insulated gate bipolar transistor (IGBT as composite of MOSFET and BJT) represented by the complex device set driving power is small, fast switching speed, state the pressure drop is small, current carrying capacity is greater than one, superior performance make it become the main device of modern power electronic technology. In order to make the compact structure of power electronic devices, the volume decreases, and often take a number of power electronic devices and necessary auxiliary device to make the form of module, then the drive, control, protection circuit and the power device together, constitute the power integrated circuit (PIC). The power of the PIC is small but it represents the power electronic technology is an important direction of development. Using electricity power electronic devices to realize industrial scale transform technology, sometimes referred to as the power electronic technology. In general, it is a form of industrial
对直流电机的速度闭环控制系统的设计 钟国梁 机械与汽车工程学院华南理工大学 中国,广州510640 电子邮件：zhgl2chl@https://www.doczj.com/doc/6510133644.html, 机械与汽车工程学院 华南理工大学 中国,广州510640 江梁中 电子邮件：jianglzh88@https://www.doczj.com/doc/6510133644.html, 该研究是由广州市科技攻关项目赞助（No.2004A10403006）。（赞助信息） 摘要 本文介绍了直流电机的速度控制原理，阐述了速度控制PIC16F877单片机作为主控元件，利用捕捉模块的特点，比较模块和在PIC16F877单片机模数转换模块将触发电路，并给出了程序流程图。系统具有许多优点，包括简单的结构，与主电路同步，稳定的移相和足够的移相范围，10000步控制的角度，对电动机的无级平滑控制，陡脉冲前沿，足够的振幅值，设定脉冲宽度，良好的稳定性和抗干扰性，并且成本低廉，这速度控制具有很好的实用价值，系统可以容易地实现。 关键词：单片机，直流电机的速度控制，控制电路，PI控制算法
1．简介 电力电子技术的迅速发展使直流电机的转速控制逐步从模拟转向数字，目前，广泛采用晶闸管直流调速传动系统设备（如可控硅晶闸管，SCR ）在电力拖动控制系统对电机供电已经取代了笨重的F-D 发电机电动机系统，尤其是单片机技术的应用使速度控制直流电机技术进入一个新阶段。在直流调速系统中，有许多各种各样的控制电路。单片机具有高性能，体积小，速度快，优点很多，价格便宜和可靠的稳定性，广泛的应用和强劲的流通，它可以提高控制能力和履行的要求实时控制（快速反应）。控制电路采用模拟或数字电路可以实现单片机。在本文中，我们将介绍一种基于单片机PIC16F877单片机的直流电机速度控制系统的分类。 2．直流电机的调速原理 在图1中，电枢电压a U ，电枢电流a I ，电枢回路总电阻a R ，电机 常数a C 和励磁磁通Φ，根据KVL 方程，电机的转速为 Φ-= a a a a C R I U n a pN C 60= a a a a U R I U ≈- )1(63.0)(84.0)1()1()()1()(10--+-=--+-=k e k e k T k e a k e a k T k T d d d d i l T T Tf Kp a T T Kp a +==+ =10)1(
外文文献 RURAL TOURISM AND SUSTAINABLE DEVELOPMENT INTRODUCTION Rural tourism is a segment of the total tourist industry which is particularly important in Hungary, in a country with no spectacular natural attractions, without seaside, high mountains, rainforest or herds of exotic animals. However, its attractive cultural landscapes with small villages, thermal springs, rivers and lakes, combined with the traditional hospitality, are able to offer pleasant experiences to the kind of tourist who is looking for relaxation and recreation in a calm setting. On one hand, rural tourism development can play an important role in the diversification of the Hungarian tourist supply and in the creation of a more complex and colourful country image. On the other hand, rural tourism is not only the end, but the means to stimulate economic growth, to increase the viability of underdeveloped regions, and to improve the living standards of local populations. If rural tourism is to fulfil all these roles, it has to be developed in a way that ensures the long-term sustainability of the resources and that of the development progress itself. But what is a sustainable way of development in rural tourism ? How can sustainability be monitored and promoted in rural destinations ? This paper attempts to answer these questions by presenting the current situation of Hungarian rural tourism through indicators that are considered to be relevant for this type of tourism. SUSTAINABLE TOURISM DEVELOPMENT The concept of sustainable development was introduced by the World Commission on Environment and Development in the Brundtland Report in 1987, defining sustainable development as "development that meets the needs of the present without compromising the ability of future generations to meet their own needs". Tourism is one of the foremost economic activities around the world, having transported more than 617 million people internationally and generated 448 billion USD in receipts in 1997 (WTO, 1998). It is a major economic force, having generated in 1996 an estimated 3,153.3 billion USD in gross output, creating employment for app. 255 million people, producing app. 10.7 per cent of world gross domestic product, investing app. 766 billion USD in new facilities
农村金融小额信贷中英文对照外文翻译文献(文档含英文原文和中文翻译) RURAL FINANCE: MAINSTREAMING INFORMAL FINANCIAL INSTITUTIONS By Hans Dieter Seibel Abstract Informal financial institutions (IFIs), among them the ubiquitous rotating savings and credit associations, are of ancient origin. Owned and self-managed by local people, poor and non-poor, they are self-help organizations which mobilize their own resources, cover their costs and finance their growth from their profits. With the expansion of the money economy, they have spread into new areas and grown in numbers, size and diversity; but ultimately, most have remained restricted in size, outreach and duration. Are they best left alone, or should they be helped to upgrade
均是精品，欢迎下载学习！！！ 电力电子技术的发展及应用 朱磊1侯振义1张开2 （空军工程大学电讯工程学院陕西西安710077） （南京理工大学动力工程学院江苏南京210000） 摘要：本文通过介绍电力电子技术的发展及应用，阐述了电力电子技术在国民经济中的重要作用，结合国家政策，描绘出我国电力电子行业的大好前景。 关键词：电力电子技术功率器件逆变能源 电力电子技术，又称功率电子技术。它主要研究各种电力电子器件，以及这些电力电子器件所构成的各种各样高效地完成对电能的变换和控制的电路或装置。它既是电子学在强电（高电压、大电流）或电工领域的一个分支，又是电工学在弱电（低电压、大电流）或电子领域的一个分支，总之是强弱电相结合的新学科。 1 电力电子技术的发展 电力电子技术的发展与功率器件的发展密切相关，1948年普通晶体管的发明引起了电子工业革命，1957年第一只晶闸管的问世，为电力电子技术的诞生奠定了基础。 1.1 电力电子技术的晶闸管时代 由于大功率硅整流器能够高效率的把工频交流电转变为直流电，因此在60年代和70年代，大功率硅整流管和晶闸管的开发与应用得到大发展，这一时期称之为电力电子技术的晶闸管时代。 1.2 电力电子技术的逆变时代 20世纪70年代，随着自关断器件的出现，电力电子技术进入了逆变时代。七十年代出现了世界范围的能源危机，交流电机变频调速因节能效果显著而迅速发展。在70年代到80年代，随着变频调速装置的普及，大功率逆变用的晶闸管、巨型功率晶体管(GTR)和门极可关断晶闸管(GT0)成为当时电力电子器件的主角。这时的电力电子技术已经能够实现整流和逆变，但工作频率较低，仅局限在中低频范围内。 1.3现代电力电子时代 80年代末期和90年代初期发展起来的以功率MOSFET和IGBT为代表的集高频、高压和大电流于一身的功率半导体复合器件，使以低频技术处理问题为主的传统电力电子学，向以高频技术处理问题为主的现代电力电子学转变创造了条件，表明传统电力电子技术已经进入现代电力电子时代。 这一时期，各种新型器件应用大规模集成电路技术，向复合化、模块化的方向发展，使得器件及结构紧凑、体积缩小，并且能够综合了不同器件的优点。在性能上，器件的容量不断增大，工作频率不断提高，目前，市场化的碳化硅器件达(3500V\1200A),智能功率模块达到(1200V\800A),在斩波器的PWM开关频率可达1MHz。 这一时期，各种新的控制方法得到了广泛应用，特别是现代电力电子技术越来越多地运用了人工智能技术。在所有人工智能学科中，神经网络将对电力电子学产生的影响最大，利用混合人工智能技术(神经一模糊，神经一遗传，神经一模糊一遗传，模糊一遗传)开发强大的智能控制以及估计方法，单个神经模糊专用集成芯片能承担无传感器矢量控制，且具有在线故障诊断和容错控制能力。基于人工智能的模糊控制在参数变化和负载转矩扰动的非线性反馈系统中可能可以提供最好的鲁棒性，在故障监测和故障耐力控制中将会起到越来越重要的作用。 2电力电子的技术应用 随着科技的不断发展和人们要求的不断提高，电力电子技术的应用越来越广泛。当今世界先进工业国家正处于由“工业经济”模式向“信息经济”模式转变的时期。电力电子技术作为信息产业与传统产业之间的桥梁，是在非常广泛的领域内改造传统产业、支持高新技术发展的基础。因此，电力电子技术将在国民经济中扮演着越来越重要的角色。
可编程电源能够接收AC和DC输入功率 背景 许多电子设备，如电脑，个人数字助理（PDA）、移动电话、光盘和盒式磁带播放器等，目的是供电从交流（AC）和直流（DC）10个电源。交流电源包括墙壁插座，而直流电源可包括电池和车辆电源，如汽车点烟器和飞机座椅电源（如授权系统）。为了从这些交流和直流电源接收功率，电子设备通常必须具有多个独立的功率转换电源供应。此外，每个电子设备可以接收在不同要求的电流或电压下的操作功率。这些业务的要求也会改变关于电子设备的状态（例如，是否电子设备的电池正在充电）。 电力电子设备如计算机、人工提供外部电源。这个外部电源可能是一个开关电源的重量可能接近一磅，可能是约八英寸长，四英寸宽，高约四英寸。在此外，电源可包括固定输出电缆或固定输入电缆和插头，使之更加困难压缩存储。因此，这样的外部电源贡献子—大量额外的重量，电脑用户必须携带他或她允许电池充电和电气插座或其他电源的操作。此外，外部电源可以笨重，不可获得在典型情况下，便携式电子设备，如笔记本电脑和子笔记本电脑。 日本，一个单独的电源可能需要需要每个外围设备，如打印机、外部存储器（例如，磁盘驱动器）或类似。因此，用户需要电源消耗和增加一些不必要的重量空间。这些电源可设计用于与一个特定类型的交流或直流电源。因此，特别是便携式电子设备，它是可取的，能够接收电力从任何数量的交流和直流电源，用户可能需要不断进行适用于多种电源的多电源可能提供的来源。 这些缺陷在解决，编号6266261，5636110，5838554，6091611，and6172884，它描述了可编程电源。这个输出可以耦合英特尔：多变的技巧电源输出电缆或终端。一双电源转换为交流和直流电源输入信号转换成直流电源输出信号也是描述.这些引用，但是，不披露电源可以紧包装和容易存储.他们也没有描述如何互换提示可能是方便和紧凑的存储以防止大坝，这可能是特别有问题，提示小的尺寸。 其他讨论电力供应的参考接收交流和直流电源输入简单有效。例如，美国专利号，描述具有固定输入电缆和用于接收交流和直流电源输入信号的插头用于将直流输出电缆传输到电子设备的固定输出电缆和连接器。此外，该物参考并描述任何用于将交流或直流输入功率信号我各种特性的输入功率匹配为直流电源输出信号需要一个以上的电子设备。 电源在包括固定的交流输入插头，DC插件可安装，电源可以获得直流电源输入回答信号与等人参考，输入电缆的交流输入插头称为固定。虽然直流插头附件和输出电缆