外文翻译译文
英文文献翻译
外文文献原稿和译文原稿Sodium Polyacrylate:Also known as super-absorbent or “SAP”(super absorbent polymer), Kimberly Clark used to call it SAM (super absorbent material). It is typically used in fine granular form (like table salt). It helps improve capacity for better retention in a disposable diaper, allowing the product to be thinner with improved performance and less usage of pine fluff pulp. The molecular structure of the polyacrylate has sodium carboxylate groups hanging off the main chain. When it comes in contact with water, the sodium detaches itself, leaving only carboxylions. Being negatively charged, these ions repel one another so that the polymer also has cross-links, which effectively leads to a three-dimensional structure. It has hige molecular weight of more than a million; thus, instead of getting dissolved, it solidifies into a gel. The Hydrogen in the water (H-O-H) is trapped by the acrylate due to the atomic bonds associated with the polarity forces between the atoms. Electrolytes in the liquid, such as salt minerals (urine contains 0.9% of minerals), reduce polarity, thereby affecting superabsorbent properties, especially with regard to the superabsorbent capacity for liquid retention. This is the main reason why diapers containing SAP should never be tested with plain water. Linear molecular configurations have less total capacity than non-linear molecules but, on the other hand, retention of liquid in a linear molecule is higher than in a non-linear molecule, due to improved polarity. For a list of SAP suppliers, please use this link: SAP, the superabsorbent can be designed to absorb higher amounts of liquids (with less retention) or very high retentions (but lower capacity). In addition, a surface cross linker can be added to the superabsorbent particle to help it move liquids while it is saturated. This helps avoid formation of "gel blocks", the phenomenon that describes the impossibility of moving liquids once a SAP particle gets saturated.History of Super Absorbent Polymer ChemistryUn til the 1980’s, water absorbing materials were cellulosic or fiber-based products. Choices were tissue paper, cotton, sponge, and fluff pulp. The water retention capacity of these types of materials is only 20 times their weight – at most.In the early 1960s, the United States Department of Agriculture (USDA) was conducting work on materials to improve water conservation in soils. They developed a resin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules (i.e. starch-grafting). The hydrolyzed product of the hydrolysis of this starch-acrylonitrile co-polymer gave water absorption greater than 400 times its weight. Also, the gel did not release liquid water the way that fiber-based absorbents do.The polymer came to be known as “Super Slurper”.The USDA gave the technical know how several USA companies for further development of the basic technology. A wide range of grating combinations were attempted including work with acrylic acid, acrylamide and polyvinyl alcohol (PVA).Since Japanese companies were excluded by the USDA, they started independent research using starch, carboxy methyl cellulose (CMC), acrylic acid, polyvinyl alcohol (PVA) and isobutylene maleic anhydride (IMA).Early global participants in the development of super absorbent chemistry included Dow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical, Enka (Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan.In the early 1970s, super absorbent polymer was used commercially for the first time –not for soil amendment applications as originally intended –but for disposable hygienic products. The first product markets were feminine sanitary napkins and adult incontinence products.In 1978, Park Davis (d.b.a. Professional Medical Products) used super absorbent polymers in sanitary napkins.Super absorbent polymer was first used in Europe in a baby diaper in 1982 when Schickendanz and Beghin-Say added the material to the absorbent core. Shortly thereafter, UniCharm introduced super absorbent baby diapers in Japan while Proctor & Gamble and Kimberly-Clark in the USA began to use the material.The development of super absorbent technology and performance has been largely led by demands in the disposable hygiene segment. Strides in absorption performance have allowed the development of the ultra-thin baby diaper which uses a fraction of the materials – particularly fluff pulp – which earlier disposable diapers consumed.Over the years, technology has progressed so that there is little if any starch-grafted super absorbent polymer used in disposable hygienic products. These super absorbents typically are cross-linked acrylic homo-polymers (usually Sodium neutralized).Super absorbents used in soil amendments applications tend to be cross-linked acrylic-acrylamide co-polymers (usually Potassium neutralized).Besides granular super absorbent polymers, ARCO Chemical developed a super absorbent fiber technology in the early 1990s. This technology was eventually sold to Camelot Absorbents. There are super absorbent fibers commercially available today. While significantly more expensive than the granular polymers, the super absorbent fibers offer technical advantages in certain niche markets including cable wrap, medical devices and food packaging.Sodium polyacrylate, also known as waterlock, is a polymer with the chemical formula [-CH2-CH(COONa)-]n widely used in consumer products. It has the ability to absorb as much as 200 to 300 times its mass in water. Acrylate polymers generally are considered to possess an anionic charge. While sodium neutralized polyacrylates are the most common form used in industry, there are also other salts available including potassium, lithium and ammonium.ApplicationsAcrylates and acrylic chemistry have a wide variety of industrial uses that include: ∙Sequestering agents in detergents. (By binding hard water elements such as calcium and magnesium, the surfactants in detergents work more efficiently.) ∙Thickening agents∙Coatings∙Fake snowSuper absorbent polymers. These cross-linked acrylic polymers are referred to as "Super Absorbents" and "Water Crystals", and are used in baby diapers. Copolymerversions are used in agriculture and other specialty absorbent applications. The origins of super absorbent polymer chemistry trace back to the early 1960s when the U.S. Department of Agriculture developed the first super absorbent polymer materials. This chemical is featured in the Maximum Absorbency Garment used by NASA.译文聚丙烯酸钠聚丙烯酸钠,又可以称为超级吸收剂或者又叫高吸水性树脂,凯博利克拉克教授曾经称它为SAM即:超级吸收性物质。
北斗定位-毕业论文外文文献翻译
外文文献原稿和译文原稿Beidou positioningPrefaceNavigation satellite systems can provide all time, all weather and high accuracy positioning, navigation and timing services to users on the earth surface or in the near-earth space. It is an important space inf rastructure, which extends people’s range of activities and promotes social development. Satellite navigation is bringing up revolutionary changes to the world politics, economy, military, technology and culture.With a long history and a splendid culture, China is one of the important cradles of early human civilization. In ancient times, Chinese people used the Big Dipper (Beidou) for identifying directions, and invented the world’s first navigation device, the ancient compass (Sinan), which was a great contribution to the development of world civilization. In modern society, the Chinese-built BeiDou(COMPASS) system will become another contribution to the mankind.In early 1980s, China began to actively study the navigation satellite systems in line with C hina’s conditions. In 2000, BeiDou Navigation Demonstration System is basically established, which made China the third nation in possession of an independent navigation satellite system following the United States and Russia. At present, China is steadily accelerating the construction of the BeiDou Navigation Satellite System, and has already successfully launched 10 satellites so far.The BeiDou system will meet the demands of China’s national security, economic development, technological advances and social progress, safeguard national interests and enhance the comprehensive national strength. The BeiDou system will commit to providing stable, reliable and quality satellite navigation services for global users. Along with other GNSS providers, the BeiDou system will jointly promote the development of satellitenavigation industry, make contributions to human civilization and social development, serve the world and benefit the mankind.I. System DescriptionThe BeiDou system is comprised of three major components: space constellation, ground control segment and user terminals. The space constellation consists of five GEO satellites and 30 non-GEO satellites. The GEO satellites are positioned at 58.75°E, 80°E, 110.5°E, 140°E and 160°E respectively. The non-GEO satellites include 27 MEO satellites and three IGSO satellites. The MEO satellites are operating in an orbit with an altitudeof 21,500 km and an inclination of 55°, which are evenly distributed in three orbital planes. The IGSO satellites are operating in an orbit with an altitude of 36,000 km and an inclination of 55°, which are evenly distributed in three inclined geo-synchronous orbital planes. The subsatellite track for the three IGSO satellites are coincided while the longitude of the intersection point is at 118°E, with a phase difference of 120°.Ground control segment consists of several Master Control Stations (MCS), Upload Stations (US) and a network of globally distributed Monitor Stations (MS). The main tasks of MCS are to collect observing data from each MS, to process data, to generate satellite navigation messages, wide area differential data and integrity information, to perform mission planning and scheduling, and to conduct system operation and control. The main tasks of Upload Stations include completing the upload of satellite navigation messages, wide area differential data and integrity information, controlling and managing the payload. The tasks of Monitor Stations include continuous tracking and monitoring of navigation satellites, receiving navigation signals, sending observational data to the Master Control Station for the satellites orbit determination and time synchronization.The user terminals include various BeiDou user terminals, and terminals compatible with other navigation satellite systems, to meet different application requirements from different fields and industries.The time reference for the BeiDou Navigation Satellite System uses BeiDou Time (BDT). BDT’s length of second is a SI second. BDT was zero at 0:00:00 on Janu ary 1, 2006 Coordinated Universal Time (UTC). BDT is a continuous system, traceable to the UTC time maintained by the National Time Service Center (NTSC) of ChineseAcademy ofSciences, which is referred to as UTC (NTSC). The leap seconds with UTC information is broadcasted in the navigation messages. The difference between BDT and UTC maintains within 100ns.The coordinate framework of BeiDou system adopts China Geodetic Coordinate System 2000 (CGCS2000).Upon the full system completion, the BeiDou Navigation Satellite System can provide positioning, navigation and timing services to worldwide users. It can also provide wide area differential services with the accuracy of 1m and short messages services with the capacity of 120 Chinese characters each time.·Main functions: positioning, velocity measurement, one-way and two-way timing, short messages·Service area: global·Positioning accuracy: better than 10m·Velocity accuracy: better than 0.2m/s·Timing accuracy: 20nsII. System DevelopmentThe BeiDou system has followed the development concept of starting with regional services first and expanding to global services later. A three-step development strategy has been taken, with specifics as follows:Phase I: BeiDou Navigation Satellite Demonstration System. In 1994, Chinastarted the construction of BeiDou Navigation Satellite Demonstration System. In 2000, two BeiDou navigation experiment satellites were launched, and the BeiDou Navigation Satellite Demonstration System was basically established. In 2003, the third BeiDou navigation experiment satellite was launched, further enhancing the performance of the BeiDou Navigation Satellite Demonstration System.BeiDou Navigation Satellite Demonstration System consists of three major components: space constellation, ground control segment and user terminals. The space constellation includes three geostationary orbit (GEO) satellites, positioned at longitude of 80 degrees East, 110.5 degrees East and 140 degrees East respectively above the equator. Ground control segment consists of the ground control center and a number of calibrationstations. The ground control center is to complete satellite orbit determination, ionospheric correction, user location determination and user short message information exchange and processing. The calibration ground control stations are mainly to provide the distance measurement and correction parameters to the ground control center.The user terminals include the hand-held type, vehicle type, command type and other types of terminals, capable of position service application, location coordinates information receiving and other functions.The main functions and performance specifications of the BeiDou Navigation Satellite Demonstration System are as follows:·Main functions: positioning, one-way and two-way timing, short message communications;·Service Area: China and the surrounding areas;·Positioning Accuracy: better than 20 meters;·Timing Accuracy: 100 ns one-way, two-way 20 ns;·Short message communications: 120 Chinese characters per time.Phase II: BeiDou Navigation Satellite (regional) System. In 2004, Chinastarted construction of BeiDou Navigation Satellite System. In 2007, the first satellite, a round medium earth orbit satellite (COMPASS-M1) was launched. By 2012, the BeiDou system will consist of 14 satellites, including five GEO satellites, five IGSO satellites (two in-orbit spares), and four MEO satellites.The functions and performance parameters of BeiDou Navigation Satellite (regional) System are as follows:·Main functions: positioning, velocity measurement, one-way and two-way timing, short message communications;·Service Area: China and part of Asia- Pacific region ;·Positioning Accuracy: better than 10 meters;·Velocity Accuracy: better than 0.2 m/s;·Timing Accuracy: 50 ns;·Short message communications: 120 Chinese characters per message.Phase III: BeiDou Navigation Satellite System will completely be established by 2020.III. System ApplicationsSince it was officially brought into service in 2003, the BeiDou Navigation Satellite Demonstration System has been widely used in transportation, marine fisheries, hydrological monitoring, weather forecasting, forest fire prevention, timing for communication systems, power distribution, disaster mitigation, national security, and many other fields, which has been resulting in significant social and economic benefits. Particularly, the system has played an important role in the South China frozen disaster, earthquake relief in Wenchuan, SichuanProvince and Yushu, Qinghai Province, the Beijing Olympic Games, and the Shanghai World Expo.—In the field of transportation, built on the Beidou Navigation Satellite Demonstration System, applications such as Xinjiang Satellite Navigation Monitoring System of Public Transport, the Highway Infrastructure Safety Monitoring System, and the Port Scheduling High-precision Real-time Position Monitoring System, have promoted the BeiDou system and achieved a good demonstration effect.—In marine fisheries, built on the BeiDou Navigation Satellite Demonstration System, the marine fisheries integrated information service platform has provided vessel position monitoring, emergency rescue, information distribution, fishing boats in and out of port management and other services to the fishery administration departments.—The hydrological monitoring system, based on the BeiDou Navigation Satellite Demonstration System, has realized the real-time transmission of hydrological forecast information in mountainous regions, which has improved the accuracy o f the disaster forecasting and has helped the planning and scheduling programs for the flood and drought control.—In the field of weather forecasting, a series of BeiDou terminal equipment have been developed for weather forecast, and various practical and feasible system solutions have been worked out to address the automatic data transmission issues for the China Meteorological Administration and a number of local weather centers and stations.—In the field of forest fire prevention, the BeiDou Navigation Satellite Demonstration System has been successfully used in forest fire prevention system. Its positioning and short message communication services have achieved good results.—In the field of time synchronization for communication systems, the successful implementation of BeiDou two-way timing demonstration program has achieved breakthroughs in some key technical areas such as long distant fiber technology, and an integrated satellite-based timing system has been developed.—In the field of power distribution, built on the BeiDou Navigation Satellite Demonstration System, the successful implementation of power system time synchronization demonstration program has created basis for the high precision applications such as the electric accident analysis, the electricity early warning and protection systems.—In the field of disaster mitigation, the navigation, positioning, short message communications and position reporting capabilities of the BeiDou Navigation Satellite Demonstration System have provided services for the nationwide real-time disaster relief commanding and dispatching, emergency communications, rapid reporting and sharing of disaster information, which has significantly improved the rapid response of the disaster emergency relief and decision-making capability.Upon the full completion, the BeiDou Navigation Satellite System will provide more high-performance positioning, navigation, timing and short-message communication services for civil aviation, shipping, railways, finance, postal and other industries.IV. International Exchange and CooperationThe international exchange and cooperation for the BeiDou Navigation Satellite System will be carried out in an active and pragmatic way, which is in line withChina’s foreign policies, focusing on China's basic tasks and strategic objectives for the construction of navigation satellite systems, using the domestic and international markets and resources in a coordinated way. The international exchange and cooperation will be proceeded in a phased, focus-centered, non-discriminatory and selective approach in accordance with the overall development plan of China's navigation satellite system. It will be built upon the basis of equality, mutual benefit, mutual complementarity, peaceful utilization and mutual development and the generally accepted principles of the international laws.The BeiDou Navigation Satellite System adheres to the open and friendly attitude, and has already carried out extensive exchanges and consultation with the countries that have navigation satellite systems, to promote navigation satellite system compatibility and interoperability globally. Through the exchange and cooperation with countries that do not have a navigation satellite system, we also support their use of the existing resources globally and share the benefits of the satellite navigation development.China's international exchange and cooperation in the field of satellite navigation started in the 1990s. In nearly 20 years, various forms of activities have been carried out with extensive results.In 1994, under the framework of International Telecommunication Union(ITU),China started the BeiDou Navigation Satellite System frequency coordination activities. Satellite network information was submitted in accordance with the BeiDou system construction plan and progress. International frequency coordination has been carried out in a phased, step by step, focus-centered approach. China has actively participated bilateral frequency coordination activities with Europe, the UnitedStates and Russia, and has actively taken part in the World Radiocommunication Conference and the meetings of ITU study groups and working groups.China, as an important member of the International Committee on Global Navigation Satellite Systems (ICG), has participated in every ICG General Assembly Meeting and the ICG Providers Forum. In 2007, China became one of the four core providers designated by the organization. Focusing on compatibility and interoperability, China has carried out the extensive exchange and cooperation with the other navigation satellite systems in the world. The Technical Working Group (TWG) on compatibility and interoperability between BeiDou and Galileo was established. Until now, seven TWG meetings have been held.China actively participates, organizes and hosts international academic exchanges on satellite navigation, which include the American Institute of Navigation (ION) Conferences, the International Symposium on GPS/GNSS (ISGNSS), Munich Satellite Navigation Summit and other international conferences and forums. The China academic conferenceon satellite navigation is held annually, together with many other forums and seminars.China encourages and supports domestic research institutions, industrial enterprises, universities and social organizations, under the guidance of the government policy, to carry out international exchanges, coordination and cooperation activities with other countries and international organizations in the fields of the compatibility and interoperability, satellite navigation standards, coordinates frame, time reference, application development and scientific research. China has been actively engaged in international activities in terms of monitoring and assessment of open service for GNSS to promote the BeiDou Navigation Satellite System better serving the global users, and to promote the development of satellite navigation technology.ConclusionThe rapid development of the BeiDou Navigation Satellite System is attributedto China's reform and opening-up policy as well as the sustainable development of economy. As always, China will continue to promote the Global Navigation Satellite System construction and industrial development, to encourage the use of new satellite navigation technologies to provide new services, meeting the growing diversified needs of the people. By actively propelling international exchanges and cooperation, China will realize the compatibility and interoperability between the BeiDou Navigation Satellite System and other navigation satellite systems in the world. China will provide global customers with high performance and highly reliable positioning, navigation and timing services.The Launch Record of BeiDouNavigation Satellites·October 31, 2000, launch of 1st BeiDou navigation experiment satellite.·December 21, 2000, launch of 2nd BeiDou navigation experiment satellite.·May 25, 2003, launch of the 3rd BeiDou navigation experiment satellite.·February 3, 2007, launch of the 4th BeiDou navigation experiment satellite.·April 14, 2007, launch of the 1st BeiDou navigation satellite.·April 15, 2009, launch of the 2nd Beidou navigation satellite.·January 17, 2010, launch of the 3rd BeiDou navigation satellite.·June 2, 2010, launch of the 4th BeiDou navigation satellite.·August 1, 2010, launch of the 5th BeiDou navigation satellite.·November 1, 2010, launch of the 6th BeiDou navigation satellite. ·December 18, 2010, launch of the 7th BeiDou navigation satellite. ·April 10, 2011, launch of the 8th BeiDou navigation satellite. ·July 27, 2011, launch of the 9th BeiDou navigation satellite. ·December 2, 2011, launch of the 10th BeiDou navigation satellite.译文北斗定位前言卫星导航系统可以提供所有的时间,所有天气情况下用户在地球表面或近地空间的高精度定位、导航和授时服务。
英译汉佳作欣赏
英译汉:佳译赏析巧选主语成妙译(1)原文】饱经沧桑的20世纪仅剩下几个春秋,人类即将跨入充满希望的21世纪。
【译文】I n a few years’ time, mankind will bid farewell to the 20th c entury, a century full of vic issitudes, and enter into the 21s t c entury, a c entury full of hopes.【赏析】1995年,联合国举办纪念成立50周年庆祝活动,江主席出席并发表演说。
原文是该篇演说的第一句,是地道的汉语。
翻译此句时,一般译者往往会亦步亦趋地将原文译为两个分句,分别以“饱经沧桑的20世纪”和“人类”作主语。
但高明的译者吃透了原文的精神,选择mankind为主语统领全句,以准确而地道的英语译出,确实是一则难得的佳译,值得翻译爱好者认真体会。
英译汉:佳译赏析之“肚里的墨水”(2)【原文】T heir family had more money, more hors es, more slaves than any one els e in the Country, b ut the boys had less grammar than mos t of their poor C racker neighbors.【译文】他们家里的钱比人家多,马比人家多,奴隶比人家多,都要算全区第一,所缺少的只是他哥儿俩肚里的墨水,少得也是首屈一指的。
【赏析】原文选自Gone With the Wind。
译文忠实且流畅,算得上好译文,特别值得一提的是译者对grammar的处理,如果照搬字典自然难于翻译,但译者吃透了原句精神,译为“肚里的墨水”,真是再妥帖不过了。
英译汉:佳译赏析之“思前想后”(3)【原文】A nd in these meditations he fell asleep.【译文】他这么思前想后,就睡着了。
外文翻译
毕业设计(论文)外文资料翻译学院(系):计算机科学与工程专业:计算机科学与技术姓名:杨玉婷学号:120602127外文出处:[1]Jérôme Vouillon,Vincent Balat.From bytecode to JavaScript: the Js_of_ocaml compiler[J].Softw.Pract.Exper.,2014,44(8):Pages 951-955附件:1.外文资料翻译译文;2.外文原文。
1.外文翻译译文:总结:我们目前从OCaml字节码编译器的设计与实现JavaScript。
编译器首先将字节码转换为静态单赋值的中间表示上进行优化,在生成的JavaScript。
我们相信,以字节而不是一个高层次的语言输入是一个明智的选择。
虚拟机提供了一个非常稳定的原料药。
这样的编译器是很容易维护的。
它也方便使用,它可以添加到现有的开发工具的安装。
已经编译好的库可以直接使用,无需重新安装任何东西,最后,一些虚拟机是几种语言的目标。
字节码编译为JavaScript可以重新审视所有这些语言的Web浏览器一次。
1。
简介我们提出了一个编译器将字节码转换为JavaScript OCaml[1][2]。
这个编译器可以交互式Web应用程序客户端在ocaml.javascript是唯一的语言,很容易在大多数Web浏览器和浏览器的API提供了直接访问。
(其他平台,如Flash 和Silverlight,并没有广泛使用和集成。
)因此,强制性语言开发Web应用程序,它将能够使用各种Web浏览器上的JavaScript语言有趣:可适用于某些任务,但可以在其他语言其他情况下更合适。
特别是,能够使用相同的语言,无论是在浏览器和服务器,使它可以共享代码,并降低了语言之间的阻抗不匹配的两个层次。
例如,表单验证必须在服务器上进行,以提供安全的原因,并且在客户端上进行,以向用户提供早期反馈。
外文翻译译文
2.3.2 公制,标准尺寸图梯形齿廓标准同步皮带由聚氨酯与钢或芳纶抗拉元件制成。
符号T代表梯形齿廓标准带。
WHM公司与国内GmbH公司和德国的Hanover公司合作,在1995年前后联合开发了这种同步带。
MULCO团体在德国以Synchroflex为品牌名发行这种同步带,之后又在欧洲发行。
在1997年这种带被标准化了,其标准为DIN772。
这些带遍布世界各地,并可作为成型的环形带,无尽的连接带和开口带使用。
具有梯形齿廓和公制标准尺寸,AT同步带是T型同步带的一个发展。
它们由由聚氨酯与钢或芳纶抗拉元件制成。
与T型同步带先比,AT型同步带有更宽的齿形截面和更强的抗拉构件。
AT型同步带一个特殊的特点是带齿齿隙紧靠带轮槽底座。
德国的MULCO和Hanover公司开发了这种类型的同步带,并在1980年左右以Synchroflex为品牌发行了这种带。
这些带遍布世界各地,并可作为成型的环形带,无尽的连接带和开口带使用。
这些带ISO 13050 标准用符号H表示,也被称为HTD同步带。
HTD代表大扭矩驱动。
这种同步带是由氯丁橡胶与玻璃纤维抗拉元件和聚酰胺纤维织物制成,并由在1973年引领美国市场的Gates公司开发。
曲齿的几何形状是圆形,较大的齿高显然增加了齿承载能力和抗牙跳能力。
这种带在世界各地都可以看到,许多制造商都参与它的生产。
它们也用聚氨酯,任选与钢丝帘线或芳纶抗拉元件制造。
用户可以从无尽的成型带,开口带和连续挤压环形带中选择使用。
这些带ISO 13050 标准用符号R表示,也被称为RPP同步带。
RPP代表橡胶抛物线。
1985年意大利的公司开发了这种双抛物线齿廓的同步带,他们是由氯丁橡胶与玻璃纤维抗拉元件和聚酰胺纤维织物制成。
这种类型的同步带主要发行在欧洲南部,许多制造商都参与它们的生产。
它们也用聚氨酯,任选钢丝帘线或芳纶抗拉元件制造。
用户可以从无尽的成型带,开口带和连续挤压环形带中选择使用。
这些带ISO 13050 标准用符号S表示,也被称为STD同步带。
外文翻译及中文译文
车床用于车外圆、端面和镗孔等加工的机床称作车床。
车削很少在其他种类的机床上进行,因为其他机床都不能像车床那样方便地进行车削加工。
由于车床除了用于车外圆还能用于镗孔、车端面、钻孔和铰孔,车床的多功能性可以使工件在一次定位安装中完成多种加工。
这就是在生产中普遍使用各种车床比其他种类的机床都要多的原因。
两千多年前就已经有了车床。
现代车床可以追溯到大约1797年,那时亨利•莫德斯利发明了一种具有把主轴和丝杆的车床。
这种车床可以控制工具的机械进给。
这位聪明的英国人还发明了一种把主轴和丝杆相连接的变速装置,这样就可以切削螺纹。
车床的主要部件:床身、主轴箱组件、尾架组件、拖板组、变速齿轮箱、丝杆和光杆。
床身是车床的基础件。
它通常是由经过充分正火或时效处理的灰铸铁或者球墨铸铁制成,它是一个坚固的刚性框架,所有其他主要部件都安装在床身上。
通常在球墨铸铁制成,它是一个坚固的刚性框架,所有其他主要部件都安装在床身上。
通常在床身上面有内外两组平行的导轨。
一些制造厂生产的四个导轨都采用倒“V”,而另一些制造厂则将倒“V”形导轨和平面导轨结合。
由于其他的部件要安装在导轨上并(或)在导轨上移动,导轨要经过精密加工,以保证其装配精度。
同样地,在操作中应该小心,以避免损伤导轨。
导轨上的任何误差,常常会使整个机床的精度遭到破坏。
大多数现代车床的导轨要进行表面淬火处理。
以减少磨损和擦伤,具有更大的耐磨性。
主轴箱安装在床身一端内导轨的固定位置上。
它提供动力。
使工件在各种速度下旋转。
它基本上由一个安装在精密轴承中的空心轴和一系列变速齿轮---类似于卡车变速箱所组成,通过变速齿轮,主轴可以在许多中转速的旋转。
大多数车床有8~18中转速,一般按等比级数排列。
在现代车床上只需扳动2~4个手柄,就能得到全部挡位的转速。
目前发展的趋势是通过电气的或机械的装置进行无级变速。
由于车床的精度在很大程度上取决于主轴,因此主轴的结构尺寸较大,通常安装在紧密配合的重型圆锤滚子轴承或球轴承中。
刘颖会 外文翻译原文及译文
大连民族学院国际商学院英文翻译2007级毕业论文外文翻译资料Microfinance's Latest Growing Pains小额信贷业的发展阵痛《Knowledge Wharton》February 2nd 2011《沃顿知识》杂志 2011年2月2日译者:刘颖会大连民族学院国际商学院国际经济与贸易072班2011年6月小额信贷业发展阵痛近期的小额信贷危机源于印度南部城市安得拉邦,当地过度负债、暴力催款和借款者被迫自杀等问题引发了民众对小额信贷行业的广泛指责,并强烈呼吁政府加强监管。
10月,印度政府对损害信贷、强行控制回款天数并拖累印度最大的盈利性小额信贷公司SKS股价暴跌的小额信贷机构实施管制。
1月19日,印度储备银行发布Malegam委员会报告,建议对印度小额信贷机构施加一系列新的监管措施,包括设置利率上限、贷款限额以及对借款人的收入进行规定。
有些观察家对此表示欢迎,而悲观人士则认为此举难以避免信贷紧缩和行业崩溃。
尽管现在要分析行业前景还为时尚早,但安得拉邦的危机着实引发了民众对全球小额信贷行业的热烈讨论和深刻反省。
近期在沃顿阿瑞斯高级管理教育学院小额信贷管理培训班上,讨论的焦点集中在过度信贷、高速的行业增长以及如何在追求利润的同时更好地实现小额信贷的设立宗旨。
小额信贷业经历了一场由坏账“大地震”所引发的“痛苦的觉醒”,26名来自全球各地的社会财富计划参与者之一Kamran Azim在一堂主题为小额信贷业的增长与可持续发展的讨论中如此比喻道。
Azim是创立于1996年的巴基斯坦拉合尔小额信贷机构Kashf 基金的运营总监。
他指出,过去20到30年间,小额信贷的方式方法几乎都没有发生过变化。
但现在,突然之间,这个行业经历了一场地震。
正如该培训计划中一门课程的导言所说:“面对不断加速的变革,人们趋向于依赖传统的方式进行商业发展。
然而,正是在这样的时刻,创新方显得尤为重要。
”此外,几名学员也指出,小额信贷行业必须在兼顾客户需求的同时通过创新的方式来巩固发展。
审计风险外文文献翻译最新译文
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debtors and regulators。
and other regulated XXX verify the financial n of foreign enterprises and other n to ensure that the market's main body has as close to complete n as possible。
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which are usually based on sampling surveys。
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audit risk is XXX.n:The auditing n has e an essential part of the market economy。
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due to the repeatedn of cases XXX accountants。
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土木外文翻译原文和译文
A convection-conduction model for analysis of thefreeze-thawconditions in the surrounding rock wall of atunnel in permafrost regionsAbstractBased on the analyses of fundamental meteorological and hydrogeological conditions at the site of a tunnel in the cold regions, a combined convection-conduction model for air flow in the tunnel and temperature field in the surrounding has been constructed. Using the model, the air temperature distribution in the Xiluoqi No. 2 Tunnel has been simulated numerically. The simulated results are in agreement with the data observed. Then, based on the in situ conditions of sir temperature, atmospheric pressure, wind force, hydrogeology and engineering geology, the air-temperature relationship between the temperature on the surface of the tunnel wall and the air temperature at the entry and exit of the tunnel has been obtained, and the freeze-thaw conditions at the Dabanshan Tunnel which is now under construction is predicted.Keywords: tunnel in cold regions, convective heat exchange and conduction, freeze-thaw.A number of highway and railway tunnels have been constructed in the permafrost regions and their neighboring areas in China. Since the hydrological and thermal conditions changed after a tunnel was excavated,the surrounding wall rock materials often froze, the frost heaving caused damage to the liner layers and seeping water froze into ice diamonds,which seriously interfered with the communication and transportation. Similar problems of the freezing damage in the tunnelsalso appeared in other countries like Russia, Norway and Japan .Hence it is urgent to predict the freeze-thaw conditions in the surrounding rock materials and provide a basis for the design,construction and maintenance of new tunnels in cold regions.Many tunnels,constructed in cold regions or their neighbouring areas,pass through the part beneath the permafrost base .After a tunnel is excavated,the original thermodynamical conditions in the surroundings are and thaw destroyed and replaced mainly by the air connections without the heat radiation, the conditions determined principally by the temperature and velocity of air flow in the tunnel,the coefficients of convective heat transfer on the tunnel wall,and the geothermal heat. In order to analyze and predict the freeze and thaw conditions of the surrounding wall rock of a tunnel,presuming the axial variations of air flow temperature and the coefficients of convective heat transfer, Lunardini discussed the freeze and thaw conditions by the approximate formulae obtained by Sham-sundar in study of freezing outside a circular tube with axial variations of coolant temperature .We simulated the temperature conditions on the surface of a tunnel wall varying similarly to the periodic changes of the outside air temperature .In fact,the temperatures of the air and the surrounding wall rock material affect each other so we cannot find the temperature variations of the air flow in advance; furthermore,it is difficult to quantify the coefficient of convective heat exchange at the surface of the tunnel wall .Therefore it is not practicable to define the temperature on the surface of the tunnel wall according to the outside air temperature .In this paper, we combine the air flow convective heat ex-change and heat conduction in the surrounding rock material into one model,and simulate the freeze-thaw conditions of the surrounding rock material based on the in situ conditions of air temperature,atmospheric pressure,wind force at the entry and exit of the tunnel,and the conditions of hydrogeology and engineering geology.重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译Mathematical modelIn order to construct an appropriate model, we need the in situ fundamental conditions as a ba-sis .Here we use the conditions at the scene of the Dabanshan Tunnel. The Dabanshan Tunnel is lo-toted on the highway from Xining to Zhangye, south of the Datong River, at an elevation of 3754.78-3 801.23 m, with a length of 1 530 m and an alignment from southwest to northeast. The tunnel runs from the southwest to the northeast.Since the monthly-average air temperature is beneath 0`}C for eight months at the tunnel site each year and the construction would last for several years,the surrounding rock materials would become cooler during the construction .We conclude that, after excavation, the pattern of air flow would depend mainly on the dominant wind speed at the entry and exit,and the effects of the temperature difference between the inside and outside of the tunnel would be very small .Since the dominant wind direction is northeast at the tunnel site in winter, the air flow in the tunnel would go from the exit to the entry. Even though the dominant wind trend is southeastly in summer, considering the pressure difference, the temperature difference and the topography of the entry and exit,the air flow in the tunnel would also be from the exit to entry .Additionally,since the wind speed at the tunnel site is low,we could consider that the air flow would be principally laminar.Based on the reasons mentioned,we simplify the tunnel to a round tube,and consider that theair flow and temperature are symmetrical about the axis of the tunnel,Ignoring the influence of the air temperature on the speed of air flow, we obtain the following equation:where t ,x ,r are the time ,axial and radial coordinates; U ,V are axial and radial wind speeds; T is temperature; p is the effective pressure(that is ,air pressure divided by air density); v is the kinematic viscosity of air; a is the thermal conductivity of air; L is the length of the tunnel; R is the equivalent radius of the tunnel section; D is the length of time after the tunnel construction;,f S (t), u S (t) are frozen and thawed parts in the surrounding rock materials respectively; f λ,u λand f C ,u C are thermal conductivities and volumetric thermal capacities in frozen and thawed parts respectively; X= (x , r),ξ(t) is phase change front; Lh is heat latent of freezing water; and To is critical freezing temperature of rock ( here we assume To= -0.1℃).2 used for solving the modelEquation(1)shows flow. We first solve those concerning temperature at that the temperature of the surrounding rock does not affect the speed of air equations concerning the speed of air flow, and then solve those equations every time elapse.2. 1 Procedure used for solving the continuity and momentum equations重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译Since the first three equations in(1) are not independent we derive the second equation by xand the third equation by r. After preliminary calculation we obtain the following elliptic equation concerning the effective pressure p:Then we solve equations in(1) using the following procedures:(i ) Assume the values for U0,V0;( ii ) substituting U0,V0 into eq. (2),and solving (2),we obtain p0;(iii) solving the first and second equations of(1),we obtain U0,V1;(iv) solving the first and third equations of(1),we obtain U2,V2; (v) calculating the momentum-average of U1,v1 and U2,v2,we obtain the new U0,V0;then return to (ii);(vi) iterating as above until the disparity of those solutions in two consecutive iterations is sufficiently small or is satisfied,we then take those values of p0,U0 and V0 as the initial values for the next elapse and solve those equations concerning the temperature..2 .2 Entire method used for solving the energy equationsAs mentioned previously,the temperature field of the surrounding rock and the air flow affect each other. Thus the surface of the tunnel wall is both the boundary of the temperature field in the surrounding rock and the boundary of the temperature field in air flow .Therefore, it is difficult to separately identify the temperature on the tunnel wall surface,and we cannot independently solve those equations concerning the temperature of air flow and those equations concerning the temperature of the surrounding rock .In order to cope with this problem,we simultaneously solve the two groups of equations based on the fact that at the tunnel wall surface both temperatures are equal .We should bearin mind the phase change while solving those equations concerning the temperature of the surrounding rock ,and the convection while solving those equations concerning the temperature of the air flow, and we only need to smooth those relative parameters at the tunnel wall surface .The solving methods for the equations with the phase change are the same as in reference [3].2.3 Determination of thermal parameters and initial and boundaryconditions2.3.1 Determination of the thermal parameters. Using p= 1013.25-0.1088 H ,we calculateair pressure p at elevation H and calculate the air density ρ using formula GTP =ρ, where T is the yearly-average absolute air temperature ,and G is the humidity constant of air. Letting P C be the thermal capacity with fixed pressure, λ the thermal conductivity ,and μ the dynamic viscosity of air flow, we calculate the thermal conductivity and kinematic viscosity using the formulas ρλP C =a and ρμν=. The thermal parameters of the surrounding rock are determined from the tunnel site.2 .3.2 Determination of the initial and boundary conditions .Choose the observed monthly average wind speed at the entry and exit as boundary conditions of wind speed ,and choose the relative effective pressure p=0 at the exit ( that is ,the entry of the dominant wind trend) and ]5[22/)/1(v d kL p ⨯+= on the section of entry ( that is ,the exit of the dominant wind trend ),where k is the coefficient of resistance along the tunnel wall, d = 2R ,and v is the axial average speed. We approximate T varying by the sine law according to the data observed at the scene and provide a suitable boundary value based on the position of the permafrost base and the geothermal gradient of the thaw rock materials beneath the重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译permafrost base.3 A simulated exampleUsing the model and the solving method mentioned above,we simulate the varying law of the air temperature in the tunnel along with the temperature at the entry and exit of the Xiluoqi No.2 Tunnel .We observe that the simulated results are close to the data observed[6].The Xiluoqi No .2 Tunnel is located on the Nongling railway in northeastern China and passes through the part beneath the permafrost base .It has a length of 1 160 m running from the northwest to the southeast, with the entry of the tunnel in the northwest,and the elevation is about 700 m. The dominant wind direction in the tunnel is from northwest to southeast, with a maximum monthly-average speed of 3 m/s and a minimum monthly-average speed of 1 .7 m/s . Based on the data observed,we approximate the varying sine law of air temperature at the entry and exit with yearly averages of -5℃,-6.4℃ and amplitudes of 18.9℃ and 17.6℃respectively. The equivalent diameter is 5 .8m,and the resistant coefficient along the tunnel wall is 0.025.Since the effect of the thermal parameter of the surrounding rock on the air flow is much smaller than that of wind speed,pressure and temperature at the entry and exit,we refer to the data observed in the Dabanshan Tunnel for the thermal parameters.Figure 1 shows the simulated yearly-average air temperature inside and at the entry and exit of the tunnel compared with the data observed .We observe that the difference is less than 0 .2 `C from the entry to exit.Figure 2 shows a comparison of the simulated and observed monthly-average air temperature in-side (distance greater than 100 m from the entry and exit) the tunnel. We observe that the principal law is almost the same,and the main reason for the difference is the errors that came from approximating the varying sine law at the entry and exit; especially , the maximum monthly-average air temperature of 1979 was not for July but for August.Fig.1. Comparison of simulated and observed air temperature in Xiluoqi No.2 Tunnel in 1979.1,simulated values;2,observed valuesFig.2.The comparison of simulated and observed air temperature inside The Xiluoqi No.2 Tunnel in 1979.1,simulated values;2,observed values4 Prediction of the freeze-thaw conditions for the Dabanshan Tunnel 4 .1 Thermal parameter and initial and boundary conditionsUsing the elevation of 3 800 m and the yearly-average air temperature of -3℃, we calculate the air density p=0 .774 kg/m 3.Since steam exists In the air, we choose the thermal capacity with a fixed pressure of air ),./(8744.10C kg kJ C p = heat conductivity )./(100.202C m W -⨯=λ andand the dynamic viscosity )../(10218.96s m kg -⨯=μ After calculation we obtain the thermal diffusivity a= 1 .3788s m /1025-⨯ and the kinematic viscosity ,s m /1019.125-⨯=ν .Considering that the section of automobiles is much smaller than that of the tunnel and the auto-mobiles pass through the tunnel at a low speed ,we ignore the piston effects ,coming from the movement of automobiles ,in the diffusion of the air.We consider the rock as a whole component and choose the dry volumetric cavity 3/2400m kg d =λ,content of water and unfrozen water W=3% and W=1%, and the thermal conductivity c m W o u ./9.1=λ,c m W o f ./0.2=λ,heat重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译capacityc kg kJ C o V ./8.0= and d u f W w C γ⨯++=1)128.48.0(,d u u Ww C γ⨯++=1)128.48.0( According to the data observed at the tunnel site ,the maximum monthly-average wind speed is about 3 .5 m/s ,and the minimum monthly-average wind speed is about 2 .5 m/s .We approximate the wind speed at the entry and exit as )/](5.2)7(028.0[)(2s m t t v +-⨯=, where t is in month. The initial wind speed in the tunnel is set to be.0),,0(),)(1(),,0(2=-=r x V R r U r x U a The initial and boundary values of temperature T are set to bewhere f(x) is the distance from the vault to the permafrost base ,and R0=25 m is the radius of do-main of solution T. We assume that the geothermal gradient is 3%,the yearly-average air temperature outside tunnel the is A=-3C 0,and the amplitude is B=12C 0.As for the boundary of R=Ro ,we first solve the equations considering R=Ro as the first type of boundary; that is we assume that T=f(x)⨯3%C 0on R=Ro. We find that, after one year, the heat flow trend will have changed in the range of radius between 5 and 25m in the surrounding rock.. Considering that the rock will be cooler hereafter and it will be affected yet by geothermal heat, we appoximately assume that the boundary R=Ro is the second type of boundary; that is ,we assume that the gradient value ,obtained from the calculation up to the end of the first year after excavation under the first type of boundary value, is the gradient on R=Ro of T.Considering the surrounding rock to be cooler during the period of construction ,we calculatefrom January and iterate some elapses of time under the same boundary. Then we let the boundaryvalues vary and solve the equations step by step(it can be proved that the solution will not depend on the choice of initial values after many time elapses ).1)The yearly-average temperature on the surface wall of the tunnel is approximately equal to the ai4 .2 Calculated resultsFigures 3 and 4 show the variations of the monthly-average temperatures on the surface of the tunnel wall along with the variations at the entry and exit .Figs .5 and 6 show the year when permafrost begins to form and the maximum thawed depth after permafrost formed in different surrounding sections.Fig.3.The monthly-average temperature parison of the monthly- On the surface of Dabanshan Tunnel.I, average temperature on the surface The month,I=1,2,3,,,12 tunnel with that outside the tunnel. 1,inner temperature on the surface ;2,outside air temperatureFig.5.The year when permafrost Fig.6.The maximum thawed depth after Begins to from in different permafrost formed in different years Sections of the surroundingrock重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译4 .3 Preliminary conclusionBased on the initial-boundary conditions and thermal parameters mentioned above, we obtain the following preliminary conclusions: r temperature at the entry and exit. It is warmer during the cold season and cooler during the warm season in the internal part (more than 100 m from the entry and exit) of the tunnel than at the entry and exit . Fig .1 shows that the internal monthly-average temperature on the surface of the tunnel wall is 1.2℃ higher in January, February and December, 1℃higher in March and October, and 1 .6℃ lower in June and August, and 2qC lower in July than the air temperature at the entry and exit. In other months the infernal temperature on the surface of the tunnel wall approximately equals the air temperature at the entry and exit.2) Since it is affected by the geothermal heat in the internal surrounding section,especially in the central part, the internal amplitude of the yearly-average temperature on the surface of the tunnel wall decreases and is 1 .6℃ lower than that at the entry and exit.3 ) Under the conditions that the surrounding rock is compact , without a great amount of under-ground water, and using a thermal insulating layer(as designed PU with depth of 0.05 m and heat conductivity λ=0.0216 W/m℃,FBT with depth of 0.085 m and heat conductivity λ=0.0517W/m℃),in the third year after tunnel construction,the surrounding rock will begin to form permafrost in the range of 200 m from the entry and exit .In the first and the second year after construction, the surrounding rock will begin to form permafrost in the range of 40 and 100m from the entry and exit respectively .In the central part,more than 200m from the entry and exit, permafrost will begin to form in the eighth year. Near the center of the tunnel,permafrost will appear in the 14-15th years. During the first and second years after permafrost formed,the maximum of annual thawed depth is large (especially in the central part of the surrounding rock section) and thereafter it decreases every year. The maximum of annual thawed depth will be stable until the 19-20th yearsand will remain in s range of 2-3 m.4) If permafrost forms entirely in the surrounding rock,the permafrost will provide a water-isolating layer and be favourable for communication and transportation .However, in the process of construction,we found a lot of underground water in some sections of the surrounding rock .It will permanently exist in those sections,seeping out water and resulting in freezing damage to the liner layer. Further work will be reported elsewhere.重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译严寒地区隧道围岩冻融状况分析的导热与对流换热模型摘要通过对严寒地区隧道现场基本气象条件的分析,建立了隧道内空气与围岩对流换热及固体导热的综合模型;用此模型对大兴安岭西罗奇2号隧道的洞内气温分布进行了模拟计算,结果与实测值基本一致;分析预报了正在开凿的祁连山区大坂山隧道开通运营后洞内温度及围岩冻结、融化状况.关键词严寒地区隧道导热与对流换热冻结与融化在我国多年冻土分布及邻近地区,修筑了公路和铁路隧道几十座.由于隧道开通后洞内水热条件的变化;,普遍引起洞内围岩冻结,造成对衬砌层的冻胀破坏以及洞内渗水冻结成冰凌等,严重影响了正常交通.类似隧道冻害问题同样出现在其他国家(苏联、挪威、日本等)的寒冷地区.如何预测分析隧道开挖后围岩的冻结状况,为严寒地区隧道建设的设计、施工及维护提供依据,这是一个亟待解决的重要课题.在多年冻土及其临近地区修筑的隧道,多数除进出口部分外从多年冻土下限以下岩层穿过.隧道贯通后,围岩内原有的稳定热力学条件遭到破坏,代之以阻断热辐射、开放通风对流为特征的新的热力系统.隧道开通运营后,围岩的冻融特性将主要由流经洞内的气流的温度、速度、气—固交界面的换热以及地热梯度所确定.为分析预测隧道开通后围岩的冻融特性,Lu-nardini借用Shamsundar研究圆形制冷管周围土体冻融特性时所得的近似公式,讨论过围岩的冻融特性.我们也曾就壁面温度随气温周期性变化的情况,分析计算了隧道围岩的温度场[3].但实际情况下,围岩与气体的温度场相互作用,隧道内气体温度的变化规律无法预先知道,加之洞壁表面的换热系数在技术上很难测定,从而由气温的变化确定壁面温度的变化难以实现.本文通过气一固祸合的办法,把气体、固体的换热和导热作为整体来处理,从洞口气温、风速和空气湿度、压力及围岩的水热物理参数等基本数据出发,计算出围岩的温度场.1数学模型为确定合适的数学模型,须以现场的基本情况为依据.这里我们以青海祁连山区大坂山公路隧道的基本情况为背景来加以说明.大坂山隧道位于西宁一张业公路大河以南,海拔3754.78~3801.23 m ,全长1530 m ,隧道近西南—东北走向. 由于大坂山地区隧道施工现场平均气温为负温的时间每年约长8个月,加之施工时间持续数年,围岩在施土过程中己经预冷,所以隧道开通运营后,洞内气体流动的形态主要由进出口的主导风速所确定,而受洞内围岩地温与洞外气温的温度压差的影响较小;冬季祁连山区盛行西北风,气流将从隧道出曰流向进口端,夏季虽然祁连山区盛行东偏南风,但考虑到洞口两端气压差、温度压差以及进出口地形等因素,洞内气流仍将由出口北端流向进口端.另外,由于现场年平均风速不大,可以认为洞内气体将以层流为主基于以上基本情况,我们将隧道简化成圆筒,并认为气流、温度等关十隧道中心线轴对称,忽略气体温度的变化对其流速的影响,可有如下的方程:其中t 为时间,x 为轴向坐标,r 为径向坐标;U, V 分别为轴向和径向速度,T 为温度,P 为有效压力(即空气压力与空气密度之比少,V 为空气运动粘性系数,a 为空气的导温系数,L 为隧道长度,R 为隧道的当量半径,D 为时间长度)(t S f , )(t S u 分别为围岩的冻、融区域. f λ,u λ分别为冻、融状态下的热传导系数,f C ,u C 分别为冻、融状态下的体积热容量,X=(x,r) , )(t ξ为冻、融相变界面,To 为岩石冻结临界温度(这里具体计算时取To=-0.10C 0),h L 为水的相变潜热.重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译2 求解过程由方程(1)知,围岩的温度的高低不影响气体的流动速度,所以我们可先解出速度,再解温度.2.1 连续性方程和动量方程的求解由于方程((1)的前3个方程不是相互独立的,通过将动量方程分别对x 和r 求导,经整理化简,我们得到关于压力P 的如下椭圆型方程:于是,对方程(1)中的连续性方程和动量方程的求解,我们按如下步骤进行:(1)设定速度0U ,0V ;( 2)将0U ,0V 代入方程并求解,得0P(3)联立方程(1)的第一个和第二个方程,解得一组解1U ,1V ;(4)联立方程((1)的第一个和第三个方程,解得一组解2U ,2V ;(5)对((3) ,(4)得到的速度进行动量平均,得新的0U ,0V 返回(2) ;(6)按上述方法进行迭代,直到前后两次的速度值之差足够小.以0P ,0U ,0V 作为本时段的解,下一时段求解时以此作为迭代初值.2. 2 能量方程的整体解法如前所述,围岩与空气的温度场相互作用,壁面既是气体温度场的边界,又是固体温度场的边界,壁面的温度值难以确定,我们无法分别独立地求解隧道内的气体温度场和围岩温度场.为克服这一困难,我们利用在洞壁表面上,固体温度等于气体温度这一事实,把隧道内气体的温度和围岩内固体的温度放在一起求解,这样壁面温度将作为末知量被解出来.只是需要注意两点:解流体温度场时不考虑相变和解固体温度时没有对流项;在洞壁表面上方程系数的光滑化.另外,带相变的温度场的算法与文献[3]相同.2. 3热参数及初边值的确定热参数的确定方法: 用p=1013.25-0.1088H 计算出海拔高度为H 的隧道现场的大气压强,再由GT P =ρ计算出现场空气密度ρ,其中T 为现场大气的年平均绝对温度,G 为空气的气体常数.记定压比热为P C ,导热系数为λ,空气的动力粘性系数为μ.按ρλP C =a 和ρμν= 计算空气的导温系数和运动粘性系数.围岩的热物理参数则由现场采样测定.初边值的确定方法:洞曰风速取为现场观测的各月平均风速.取卞导风进曰的相对有效气压为0,主导风出口的气压则取为]5[22/)/1(v d kL p ⨯+=,这里k 为隧道内的沿程阻力系数,L 为隧道长度,d 为隧道端面的当量直径,ν为进口端面轴向平均速度.进出口气温年变化规律由现场观测资料,用正弦曲线拟合,围岩内计算区域的边界按现场多年冻土下限和地热梯度确定出适当的温度值或温度梯度. 3 计算实例按以上所述的模型及计算方法,我们对大兴安岭西罗奇2号隧道内气温随洞曰外气温变化的规律进行了模拟计算验证,所得结果与实测值[6]相比较,基本规律一致.西罗奇2号隧道是位十东北嫩林线的一座非多年冻土单线铁路隧道,全长1160 m ,隧道近西北一东南向,高洞口位于西北向,冬季隧道主导风向为西北风.洞口海拔高度约为700 m ,月平均最高风速约为3m/s,最低风速约为1.7m/s.根据现场观测资料,我们将进出口气温拟合为年平均分别为-5C 0和-6.4C 0,年变化振幅分别为18.9C 0和17.6C 0的正弦曲线.隧道的当量直径为5.8 m,沿程阻力系数取为0.025.由于围岩的热物理参数对计算洞内气温的影响远比洞口的风速、压力及气温的影响小得多,我们这里参考使用了大坂山隧道的资料.图1给出了洞口及洞内年平均气温的计算值与观测值比较的情况,从进口到出口,两值之差都小于0.2C 0.图2给出了洞内 (距进出口l00m 以上)月平均气温的计算值与观测值比较的情况,可以看出温度变化的基本规律完全一致,造成两值之差的主要原因是洞口气温年变化规律之正弦曲线的拟合误差,特别是1979年隧道现场月平均最高气温不是在7月份,而是在8月份.重庆交通大学土木工程专业(隧道与城市轨道交通工程方向)毕业设计外文翻译图1. 比较1979年在西罗奇周家山2号隧道仿真试验与观察的空气温度.1、模拟值;2、观测值图2。
商业插画外文文献翻译最新译文
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Architecture in a Climate of ChangePage52-Page62Low energy techniques for housingIt would appear that,for the industrialised countries,the best chance of rescue lies with the built environment because buildings in use or in the course of erection are the biggest single indirect source of carbon emissions generated by burning fossil fuels,accounting for over 50 per cent of total emissions.If you add the transport costs generated by buildings the UK government estimate is 75 per cent.It is the built environment which is the sector that can most easily accommodate fairly rapid change without pain.In fact,upgrading buildings, especially the lower end of the housing stock,creates a cluster of interlocking virtuous circles. Construction systemsHaving considered the challenge presented by global warming and the opportunities to generate fossil-free energy,it is now time to consider how the demand side of the energy equation can respond to that challenge.The built environment is the greatest sectoral consumer of energy and,within that sector,housing is in pole position accounting for 28 per cent of all UK carbon dioxide (CO2) emissions.In the UK housing has traditionally been of masonry and since the early 1920s this has largely been of cavity construction.The purpose was to ensure that a saturated external leaf would have no physical contact with the inner leaf apart from wall ties and that water would be discharged through weep holes at the damp-proof course level.Since the introduction of thermal regulations,initially deemed necessary to conserve energy rather than the planet,it has been common practice to introduce insulation into the cavity.For a long time it was mandatory to preserve a space within the cavity and a long rearguard battle was fought by the traditionalists to preserve this‘sacred space’.Defeat was finally conceded when some extensive research by the Building Research Establishment found that there was no greater risk of damp penetration with filled cavities and in fact damp through condensation was reduced.Solid masonry walls with external insulation are common practice in continental Europe and are beginning to make an appearance in the UK.In Cornwall the Penwith Housing Association has built apartments of this construction on the sea front, perhaps the most challenging of situations.The advantages of masonry construction are:● It is a tried and tested technology familiar to house building companies of all sizes.● It is durable and generally risk free as regards catastrophic failure–though not entirely.A few years ago the entire outer leaf of a university building in Plymouth collapsed due to the fact that the wall ties had corroded.● Exposed brickwork is a low maintenance system; maintenance demands rise considerably if it receives a rendered finish.● From the energy efficiency point of view,masonry homes have a relatively high thermal mass which is considerably improved if there are high density masonryinternal walls and concrete floors.Framed constructionVolume house builders are increasingly resorting to timber-framed construction with a brick outer skin,making them appear identical to full masonry construction.The attraction is the speed of erection especially when elements are fabricated off site. However,there is an unfortunate history behind this system due to shortcomings in quality control.This can apply to timber which has not been adequately cured or seasoned.Framed buildings need to have a vapour barrier to walls as well as roofs. With timber framing it is difficult to avoid piercing the barrier.There can also be problems achieving internal fixings.For the purist,the ultimate criticism is that it is illogical to have a framed building clad in masonry when it cries out for a panel,boarded,slate or tile hung external finish.Pressed steel frames for homes are now being vigorously promoted by the steel industry.The selling point is again speed of erection but with the added benefit of a guaranteed quality in terms of strength and durability of the material.From the energy point of view,framed buildings can accommodate high levels of insulation but have relatively poor thermal mass unless this is provided by floors and internal walls.Innovative techniquesPermanent Insulation Formwork Systems (PIFS) are beginning to make an appearance in Britain.The principle behind PIFS is the use of precision moulded interlocking hollow blocks made from an insulation material,usually expanded polystyrene.They can be rapidly assembled on site and then filled with pump grade concrete.When the concrete has set the result is a highly insulated wall ready for the installation of services and internal and exterior finishes.They can achieve a U-value as low as 0.11 W/m2K.Above three storeys the addition of steel reinforcement is necessary. The advantages of this system are:● Design flexibility; almost any plan shape is possible.● Ease and speed of erection;skill requirements are modest which is why it has proved popular with the self-build sector.Experienced erectors can achieve 5 m2 per man hour for erection and placement of concrete.● The finished product has high structural strength together with considerable thermal mass and high insulation value.Solar designPassive solar designSince the sun drives every aspect of the climate it is logical to describe the techniques adopted in buildings to take advantage of this fact as‘solar design’. The most basic response is referred to as‘passive solar design’.In this case buildings are designed to take full advantage of solar gain without any intermediate operations.Access to solar radiation is determined by a number of conditions:● the sun’s position relative to the principal facades of the building(solar altitude and azimuth);● site orientation and slope;● existing obstructions on the site;● potential for overshadowing from obstructions outside the site boundary.One of the methods by which solar access can be evaluated is the use of some form of sun chart.Most often used is the stereographic sun chart in which a series of radiating lines and concentric circles allow the position of nearby obstructions to insolation,such as other buildings,to be plotted.On the same chart a series of sun path trajectories are also drawn(usually one arc for the 21st day of each month); also marked are the times of the day.The intersection of the obstructions’outlines and the solar trajectories indicate times of transition between sunlight and shade. Normally a different chart is constructed for use at different latitudes (at about two degree intervals).Sunlight and shade patterns cast by the proposed building itself should also be considered.Graphical and computer prediction techniques may be employed as well as techniques such as the testing of physical models with a heliodon.Computer modelling of shadows cast by the sun from any position is offered by Integrated Environmental Solutions (IES) with its‘Suncast’program.This is a user-friendly program which should be well within normal undergraduate competence. The spacing between buildings is important if overshading is to be avoided during winter months when the benefit of solar heat gain reaches its peak.On sloping sites there is a critical relationship between the angle of slope and the level of overshading.For example, if overshading is to be avoided at a latitude of 50 N,rows of houses on a 10 north-facing slope must be more than twice as far apart than on 10 south-facing slope.Trees can obviously obstruct sunlight.However,if they are deciduous,they perform the dual function of permitting solar penetration during the winter whilst providing a degree of shading in the summer.Again spacing between trees and buildings is critical.Passive solar design can be divided into three broad categories:● direct gain;● indirect gain;● attached sunspace or conservatory.Each of the three categories relies in a different way on the‘greenhouse effect’as a means of absorbing and retaining heat.The greenhouse effect in buildings is that process which is mimicked by global environmental warming.In buildings,the incident solar radiation is transmitted by facade glazing to the interior where it is absorbed by the internal surfaces causing warming.However,re-emission of heat back through the glazing is blocked by the fact that the radiation is of a much longer wavelength than the incoming radiation.This is because the re-emission is from surfaces at a much lower temperature and the glazing reflects back such radiation to the interior.Direct gainDirect gain is the design technique in which one attempts to concentrate the majority of the building’s glazing on the sun-facing facade.Solar radiation is admitted directly into the space concerned.Two examples 30 years apart are the author’s housein Sheffield,designed in 1967 and the Hockerton Project of 1998 by Robert and Brenda Vale.The main design characteristics are:● Apertures through which sunlight is admitted should be on the solar side of the building, within about 30 of south for the northern hemisphere.● Windows facing west may pose a summer overheating risk.● Windows should be at least double glazed with low emissivity glass (Low E) as now required by the UK Building Regulations.● The main occupied living spaces should be located on the solar side of the building.● The floor should be of a high thermal mass to absorb the heat and provide thermal inertia,which reduces temperature fluctuations inside the building.● As regards the benefits of thermal mass,for the normal daily cycle of heat absorption and emission,it is only about the first 100 mm of thickness which is involved in the storage process.Thickness greater than this provides marginal improvements in performance but can be useful in some longer-term storage options.● In the case of solid floors,insulation should be beneath the slab.● A vapour barrier should always be on the warm side of any insulation.● Thick carpets should be avoided over the main sunlit and heatabsorbing portion of the floor if it serves as a thermal store.However,with suspended timber floors a carpet is an advantage in excluding draughts from a ventilated underfloor zone. During the day and into the evening the warmed floor should slowly release its heat, and the time period over which it happens makes it a very suitable match to domestic circumstances when the main demand for heat is in the early evening.As far as the glazing is concerned,the following features are recommended: ● Use of external shutters and/or internal insulating panels might be considered to reduce night-time heat loss.● To reduce the potential of overheating in the summer,shading may be provided by designing deep eaves or external louvres. Internal blinds are the most common technique but have the disadvantage of absorbing radiant heat thus adding to the internal temperature.● Heat reflecting or absorbing glass may be used to limit overheating.The downside is that it also reduces heat gain at times of the year when it is beneficial. ● Light shelves can help reduce summer overheating whilst improving daylight distribution.Direct gain is also possible through the glazing located between the building interior and attached sunspace or conservatory;it also takes place through upper level windows of clerestory designs.In each of these cases some consideration is required concerning the nature and position of the absorbing surfaces.In the UK climate and latitude as a general rule of thumb room depth should not be more than two and a half times the window head height and the glazing area should be between about 25 and 35 per cent of the floor area.Indirect gainIn this form of design a heat absorbing element is inserted between the incident solar radiation and the space to be heated;thus the heat is transferred in an indirectway.This often consists of a wall placed behind glazing facing towards the sun,and this thermal storage wall controls the flow of heat into the building.The main elements● High thermal mass element positioned between sun and internal spaces,the heat absorbed slowly conducts across the wall and is liberated to the interior some time later.● Materials and thickness of the wall are chosen to modify the heat flow.In homes the flow can be delayed so that it arrives in the evening matched to occupancy periods. Typical thicknesses of the thermal wall are 20–30 cm.● Glazing on the outer side of the thermal wall is used to provide some insulation against heat loss and help retain the solar gain by making use of the greenhouse effect.● The area of the thermal storage wall element should be about 15–20 per cent of the floor area of the space into which it emits heat.● In order to derive more immediate heat benefit,air can be circulated from the building through the air gap between wall and glazing and back into the room.In this modified form this element is usually referred to as a Trombe wall. Heat reflecting blinds should be inserted between the glazing and the thermal wall to limit heat build-up in summer.In countries which receive inconsistent levels of solar radiation throughout the day because of climatic factors (such as in the UK),the option to circulate air is likely to be of greater benefit than awaiting its arrival after passage through the thermal storage wall.At times of excess heat gain the system can provide alternative benefits with the air circulation vented directly to the exterior carrying away its heat,at the same time drawing in outside air to the building from cooler external spaces.Indirect gain options are often viewed as being the least aesthetically pleasing of the passive solar options,partly because of the restrictions on position and view out from remaining windows,and partly as a result of the implied dark surface finishes of the absorbing surfaces.As a result,this category of the three prime solar design technologies is not as widely used as its efficiency and effectiveness would suggest.Attached sunspace/conservatoryThis has become a popular feature in both new housing and as an addition to existing homes.It can function as an extension of living space,a solar heat store,a preheater for ventilation air or simply an adjunct greenhouse for plants.On balance it is considered that conservatories are a net contributor to global warming since they are often heated.Ideally the sunspace should be capable of being isolated from the main building to reduce heat loss in winter and excessive gain in summer.The area of glazing in the sunspace should be 20–30 per cent of the area of the room to which it is attached.The most adventurous sunspace so far encountered is in the Hockerton housing development which will feature later.Ideally the summer heat gain should be used to charge a seasonal thermal storage element to provide background warmth in winter.At the very least,air flow paths between the conservatory and the main building should be carefully controlled.Active solar thermal systemsA distinction must be drawn between passive means of utilising the thermal heat of the sun, discussed earlier,and those of a more‘active’nature Active systems take solar gain a step further than passive solar.They convert direct solar radiation into another form of energy.Solar collectors preheat water using a closed circuit calorifier.The emergence of Legionella has highlighted the need to store hot water at a temperature above 60 C which means that for most of the year in temperate climes active solar heating must be supplemented by some form of heating.Active systems are able to deliver high quality energy.However,a penalty is incurred since energy is required to control and operate the system known as the ‘parasitic energy requirement’.A further distinction is the difference between systems using the thermal heat of the sun,and systems,such as photovoltaic cells, which convert solar energy directly into electrical power.For solar energy to realise its full potential it needs to be installed on a district basis and coupled with seasonal storage.One of the largest projects is at Friedrichshafen.The heat from 5600 m2 of solar collectors on the roofs of eight housing blocks containing 570 apartments is transported to a central heating unit or substation.It is then distributed to the apartments as required.The heated living area amounts to 39 500 m2.Surplus summer heat is directed to the seasonal heat store which,in this case, is of the hot water variety capable of storing 12 000 m3.The scale of this storage facility is indicated by Figure 5.9.The heat delivery of the system amounts to 1915 MWh/year and the solar fraction is 47 per cent.The month by month ratio between solar and fossil-based energy indicates that from April to November inclusive,solar energy accounts for almost total demand,being principally domestic hot water.In places with high average temperatures and generous sunlight,active solar has considerable potential not just for heating water but also for electricity generation.This has particular relevance to less and least developed countries.环境变化影响下的建筑学房屋设计中的低能耗技术显而易见,在工业化国家,最好的营救机会依赖于建筑环境,因为不论是在使用的建筑或者是在建设的建筑,都是最大的、单一的、间接地由化石燃料的燃烧所引起的碳排放的源头,而这些站了所有排放的50%。
毕业论文外文翻译译文及原文
译文模型飞机设计介绍这种教学系列是书面与应用专业的飞机设计原则,以简单的无线电控制的飞机设计的水平,可以使学生易于理解。
学习模块可以依次写入,也可以单独引用。
此教学系列涵盖了许多不同的设计方面。
但是学习模块并非很详细,许多课题已省略,因为它们太复杂,难于处理,或对于简单模型飞机的设计它们的影响是微不足道的。
学习模块是休闲的,以对话式参与读者的方式,使内容更容易被非专业的读者所理解。
教师计划使用这些学习模块可以让读者自己阅读和适应课程,或者使他们以学生的角度去学习。
这是老师的决定,因为他们知道他们的学生需要学习什么,什么是适合他们课程计划和课程内容的。
各种深度的概念已被添加在学习单元的结尾。
这些可能包括复杂的飞机设计,或者更先进的数学技术。
飞机设计涵盖了众多的学科,从创意、艺术灵感、精确的数学计算,以及先进的理念帮助,以满足更广泛的教育需求。
在这里,有些学生可能会比别人提出更多的议题,并可能要继续学习飞机设计。
在指南的最后一个进一步阅读的部分已经提供了指向在线资源和印刷文本,学生可以自主学习。
也有一些建议项目学生可以学习,无论是独立或作为SACE研究项目的一部分。
大学生可能提供帮助指导学生学习,而这会给中学生学习的机会,通常在高年级本科生和硕士学位发现的研究课题。
这本手册的计划和指示,建立了两个无线电控制的飞机,在山谷景观ACE和额外的300 部。
这些文件包含建立和飞这架飞机所需的信息。
这种教学系列被写入到需要这些信息,并允许扩展,但仅靠这种教学系列是不足以建立一个无线电控制的飞机,作为构建技术和一些特定的信息没有被提供。
这个信息很容易在互联网上,有些链接会在进一步阅读环节里。
学习模块1飞机怎样飞行?基础知识让我们以一个客机开始,例如波音737,从阿德莱德飞往墨尔本。
我们忽略它的起飞和降落,来看它的主要部分“巡航”在这个期间,飞机没有更快或者更慢,也没有变高变低,没有左右转弯,只是保持一个速度平直飞行。
外文翻译资料及译文
附录C:外文翻译资料Article Source:Business & Commercial Aviation, Nov 20, 2000. 5-87-88 Interactive Electronic Technical Manuals Electronic publications can increase the efficiency of your digital aircraft and analogtechnicians.Benoff, DaveComputerized technical manuals are silently revolutionizing the aircraft maintenance industry by helping the technician isolate problems quickly, and in the process reduce downtime and costs by more than 10 percent.These electronic publications can reduce the numerous volumes of maintenance manuals, microfiche and work cards that are used to maintain engines, airframes, avionics and their associated components."As compared with the paper manuals, electronic publications give us greater detail and reduced research times," said Chuck Fredrickson, general manager of Mercury Air Center in Fort Wayne, Ind.With all the advances in computer hardware and software technologies, such as high quality digital multimedia, hypertext and the capability to store and transmit digital multimedia via CD-ROMs/ networks, technical publication companies have found an effective, cost-efficient method to disseminate data to technicians.The solution for many operators and OEMs is to take advantage of today's technology in the form of Electronic Technical Manuals (ETM) or Interactive Technical Manuals (IETM). An ETM is any technical manual prepared in digital format that has the ability to be displayed using any electronic hardware media. The difference between the types of ETM/IETMs is the embedded functionality and implementation of the data."The only drawback we had to using ETMs was getting enough computers to meet our technicians' demand," said Walter Berchtold, vice president of maintenance at Jet Aviation's West Palm Beach, Fla., facility.A growing concern is the cost to print paper publications. In an effort to reduce costs, some aircraft manufacturers are offering incentives for owners to switch from paper to electronic publications. With an average printing cost of around 10 cents per page, a typical volume of a paper technical manual can cost the manufacturer over $800 for each copy. When producing a publication electronically, average production costs for a complete set of aircraft manuals are approximately $20 per copy. It is not hard to see the cost advantages of electronic publications.Another advantage of ETMs is the ease of updating information. With a paper copy, the manufacturer has to reprint the revised pages and mail copies to all the owners. When updates are necessary for an electronic manual, changes can either be e-mailed to theowners or downloaded from the manufacturer's Web site.So why haven't more flight departments converted their publications to ETM/IETMs? The answer lies in convincing technicians that electronic publications can increase their efficiency."We had an initial learning curve when the technicians switched over, but now that they are familiar with the software they never want to go back to paper," said Fredrickson.A large majority of corporate technicians also said that while they like the concept of having a tool that aids the troubleshooting process, they are fearful to give up all of their marked-up paper manuals.In 1987, a human factors study was conducted by the U.S. government to compare technician troubleshooting effectiveness, between paper and electronic methodology, and included expert troubleshooting procedures with guidance through the events. Results of the project indicated that technicians using electronic media took less than half the time to complete their tasks than those using the paper method, and technicians using the electronic method accomplished 65 percent more in that reduced time.The report also noted that new technicians using the electronic technical manuals were 12-percent more efficient than the older, more experienced technicians. (Novices using paper took 15 percent longer than the experts.)It is interesting that 90 percent of the technicians who used the electronic manuals said they preferred them to the paper versions. This proved to the industry that with proper training, the older technicians could easily transition from paper to electronic media.Electronic publications are not a new concept, although how they are applied today is. "Research over the last 20 years has provided a solid foundation for today's IETM implementation," said Joseph Fuller of the U.S. Naval Surface Warfare Center. "IETMs such as those for the Apache, Comanche, F-22, JSTAR and V-22 have progressed from concept to military and commercial implementation."In the late 1970s, the U.S. military investigated the feasibility of converting existing paper and microfilm. The Navy Technical Information Presentation System (NTIPS) and the Air Force Computer- based Maintenance Aid System (CMAS) were implemented with significant cost savings.The report stated that transition to electronic publications resulted in reductions in corrective maintenance time, fewer false removals of good components, more accurate and complete maintenance data collection reports, reduction in training requirements and reduced system downtime.The problem that the military encountered was ETMs were created in multiple levels of complexity with little to no standardization. Options for publications range from simple page-turning programs to full-functioning automated databases.This resulted in the classification of ETMs so that the best type of electronic publication could be selected for the proper application.Choosing a LevelWith all of the OEM and second- and third-party electronic publications that are available it is important that you choose the application level that is appropriate for your operation.John J. Miller, BAE Systems' manager of electronic publications, told B/CAthat "When choosing the level of an ETM/IETM, things like complexity of the aircraft and its systems, ease of use, currency of data and commonality of data should be the deciding factors; and, of course, price. If operational and support costs are reduced when you purchase a full-functioning IETM, then you should purchase the better system."Miller is an expert on the production, sustainment and emerging technologies associated with electronic publications, and was the manager of publications for Boeing in Philadelphia.Electronic publications are classified in one of five categories. A Class 1 publication is a basic electronic "page turner" that allows you to view the maintenance manual as it was printed. With a Class 2 publication all the original text of the manual is viewed as one continuous page with no page breaks. In Class 3, 4 and 5 publications the maintenance manual is viewed on a computer in a frame-based environment with increasing options as the class changes. (See sidebar.)Choosing the appropriate ETM for your operation is typically limited to whatever is being offered on the market, but since 1991 human factors reports state the demand has increased and, therefore, options are expected to follow.ETM/IETM ProvidersCompanies that create ETM/IETMs are classified as either OEM or second party provider. Class 1, 3 and 4 ETM/IETMs are the most commonly used electronic publications for business and commercial operators and costs can range anywhere from $100 to $3,000 for each ETM/ IETM. The following are just a few examples ofETM/IETMs that are available on the market.Dassault Falcon Jet offers operatorsof the Falcon 50/50EX, 900/900EX and 2000 a Class 4 IETM called the Falcon Integrated Electronic Library by Dassault (FIELD). Produced in conjunction with Sogitec Industries in Suresnes Cedex, France, the electronic publication contains service documentation, basic wiring, recommended maintenance and TBO schedules, maintenance manual, tools manual, service bulletins, maintenance and repair manual, and avionics manual.The FIELD software allows the user to view the procedures and hot- link directly to the Illustrated parts catalog. The software also enables the user to generate discrepancy forms, quotation sheets, annotations in the manual and specific preferences for each user.BAE's Miller said most of the IETM presentation systems have features called "Technical Notes." If a user of the electronic publication notices a discrepancy or needs to annotate the manual for future troubleshooting, the user can add a Tech Note (an electronic mark-up) to the step or procedure and save it to the base document. The next time that or another user is in the procedure, clicking on the tech note icon launches a pop-up screen displaying the previous technician's comments. The same electronic transfer of tech notes can be sent to other devices by using either a docking station or through a network server. In addition, systems also can use "personal notes" similar to technical notes that are assigned ID codes that only the authoring technician can access.Requirements for the FIELD software include the minimum of a 16X CD-ROM drive,Pentium II 200 MHz computer, Windows 95, Internet Explorer 4 SP 1 and Database Access V3.5 or higher.Raytheon offers owners of Beech and Hawker aircraft a Class 4 IETM called Raytheon Electronic Publication Systems (REPS). The REPS software links the frame-based procedures with the parts catalog using a single CD-ROM.Raytheon Aircraft Technical Publications said other in- production Raytheon aircraft manual sets will be converted to the REPS format, with the goal of having all of them available by 2001. In addition Raytheon offers select Component Maintenance Manuals (CMM). The Class 1 ETM is a stand-alone "page-turner" electronic manual that utilizes the PDF format of Adobe Acrobat.Other manufacturers including Bombardier, Cessna and Gulfstream offer operators similar online and PDF documentation using a customer- accessed Web account.Boeing is one manufacturer that has developed an onboard Class 5 IETM. Called the Computerized Fault Reporting System (CFRS), it has replaced the F-15 U.S. Air Force Fault Reporting Manuals. Technologies that are currently being applied to Boeing's military system are expected to eventually become a part of the corporate environment.The CFRS system determines re-portable faults by analyzing information entered during a comprehensive aircrew debrief along with electronically recovered maintenance data from the Data Transfer Module (DTM). After debrief the technicians can review aircraft faults and schedule maintenance work to be performed. The maintenance task is assigned a Job Control Number (JCN) and is forwarded electronically to the correct work center or shop. Appropriate information is provided to the Air Force's Core Automated Maintenance System (CAMS).When a fault is reported by pilot debrief, certain aircraft systems have the fault isolation procedural data on a Portable Maintenance Aid (PMA). The JCN is selected on a hardened laptop with a wireless Local Area Network (LAN) connection to the CFRS LAN infrastructure. The Digital Wiring Data System (DWDS) displays aircraft wiring diagrams to the maintenance technician for wiring fault isolation. On completion of maintenance, the data collected is provided to the Air Force, Boeing and vendors for system analysis.Third party IETM developers such as BAE Systems and Dayton T. Brown offer OEMs the ability to subcontract out the development of Class 1 through 5 ETM/IETMs. For example, Advantext, Inc. offers PDF and IPDF Class 1 ETMs for manufacturers such as Piper and Bell Helicopters. Technical publications that are available include maintenance manuals, parts catalogs, service bulletins, wiring diagrams, service letters and interactive parts ordering forms.The difference between the PDF and IPDF version is that the IPDF version has the ability to search for text and include hyperlinks. A Class 1 ETM, when printed, is an exact reproduction of the OEM manuals, including any misspellings or errors. Minimum requirements for the Advantext technical publications is a 486 processor, 16 MB RAM with 14 MB of free hard disk space and a 4X CD-ROM or better.Aircraft Technical Publishers (ATP) offers Class 1, 2 and 3 ETM/ IETMsfor the Beechjet 400/400A; King Air 300/ 350, 200 and 90; Learjet 23/24/25/28/29/35/36/55; Socata TB9/10/20/21 and TBM 700A; Sabreliner 265-65, -70 and -80; andBeech 1900. The libraries can include maintenance manuals, Illustrated parts bulletins, wiring manuals, Airworthiness Directives, Service Bulletins, component maintenance manuals and structural maintenance manuals. System minimum requirements are Pentium 133 MHz, Windows 95 with 16 MB RAM, 25 MB free hard disk space and a 4X CD-ROM or better.Additional providers such as Galaxy Scientific are providing ETM/ IETMs to the FAA. This Class 2, 3 and 4 publication browser is used to store, display and edit documentation for the Human Factors Section of the administration."Clearly IETMs have moved from research to reality," said Fuller, and the future looks to hold more promise.The Future of Tech PubsThe use of ETM/IETMs on laptop and desktop computers has led research and development corporations to investigate the human interface options to the computer. Elements that affect how a technician can interface with a computer are the work environment, economics and ease of use. Organizations such as the Office of Naval Research have focused their efforts on the following needs of technicians: -- Adaptability to the environment.-- Ease of use.-- Improved presentation of complex system relationship.-- Maximum reuse and distribution of engineering data.-- Intelligent data access.With these factors in mind, exploratory development has begun in the areas of computer vision, augmented reality display and speech recognition.Computer vision can be created using visual feedback from a head- mounted camera. The camera identifies the relative position and orientation of an object in an observed scene, and the object is used to correlate the object with a three-dimensional model. In order for a computer vision scenario to work, engineering data has to be provided through visually compatible software.When systems such as Sogitech's View Tech electronic publication browser and Dassault Systemes SA's Enovia are combined, a virtual 3D model is generated.The digital mockup allows the engineering information to directly update the technical publication information. If a system such as CATIA could be integrated into a Video Reference System (VRS), then it could be possible that a technician would point the camera to the aircraft component, the digital model identifies the component and the IETM automatically displays the appropriate information.This example of artificial intelligence is already under development at companies like Boeing and Dassault. An augmented reality display is a concept where visual cues are presented to users on a head-mounted, see-through display system.The cues are presented to the technician based on the identification of components on a 3D model and correlation with the observed screen. The cues are then presented as stereoscopic images projected onto the object in the observed scene.In addition a "Private Eye" system could provide a miniature display of the maintenance procedure that is provided from a palm- size computer. Limited success hascurrently been seen in similar systems for the disabled. The user of a Private Eye system can look at the object selected and navigate without ever having to touch the computer. Drawbacks from this type of system are mental and eye fatigue, and spatial disorientation.Out of all the technologies, speech recognition has developed into an almost usable and effective system. The progression through maintenance procedures is driven by speaker-independent recognition. A state engine controls navigation, and launches audio responses and visual cues to the user. Voice recognition software is available, although set up and use has not been extremely successful.Looking at other industries, industrial manufacturing has already started using "Palm Pilot" personal digital assistants (PDAs) to aid technicians in troubleshooting. These devices allow the technician to have the complete publication beside them when they are in tight spaces. "It would be nice to take the electronic publications into the aircraft, so we are not constantly going back to the work station to print out additional information," said Jet Aviation's Berchtold.With all the advantages that a ETM/ IETM offers it should be noted that electronic publications are not the right solution all of the time, just as CBT is not the right solution for training in every situation. Only you can determine if electronic publications meet your needs, and most technical publication providers offer demo copies for your review. B/CA IllustrationPhoto: Photograph: BAE Systems' Christine Gill prepares a maintenance manual for SGML conversion BAE Systems; Photograph: Galaxy Scientific provides the FAA's human factors group with online IETM support.; Photograph: Raytheon's Class 4 IETM "REPS" allows a user to see text and diagrams simultaneously with hotlinks to illustrated parts catalogs.外文翻译资料译文部分文章出处:民航商业杂志,2000-11-20,5-87-88交互式电子技术手册的电子出版物可以提高数字飞机和模拟技术的效率。
5、外文文献翻译(附原文)产业集群,区域品牌,Industrial cluster ,Regional brand
外文文献翻译(附原文)外文译文一:产业集群的竞争优势——以中国大连软件工业园为例Weilin Zhao,Chihiro Watanabe,Charla-Griffy-Brown[J]. Marketing Science,2009(2):123-125.摘要:本文本着为促进工业的发展的初衷探讨了中国软件公园的竞争优势。
产业集群深植于当地的制度系统,因此拥有特殊的竞争优势。
根据波特的“钻石”模型、SWOT模型的测试结果对中国大连软件园的案例进行了定性的分析。
产业集群是包括一系列在指定地理上集聚的公司,它扎根于当地政府、行业和学术的当地制度系统,以此获得大量的资源,从而获得产业经济发展的竞争优势。
为了成功驾驭中国经济范式从批量生产到开发新产品的转换,持续加强产业集群的竞争优势,促进工业和区域的经济发展是非常有必要的。
关键词:竞争优势;产业集群;当地制度系统;大连软件工业园;中国;科技园区;创新;区域发展产业集群产业集群是波特[1]也推而广之的一个经济发展的前沿概念。
作为一个在全球经济战略公认的专家,他指出了产业集群在促进区域经济发展中的作用。
他写道:集群的概念,“或出现在特定的地理位置与产业相关联的公司、供应商和机构,已成为了公司和政府思考和评估当地竞争优势和制定公共决策的一种新的要素。
但是,他至今也没有对产业集群做出准确的定义。
最近根据德瑞克、泰克拉[2]和李维[3]检查的关于产业集群和识别为“地理浓度的行业优势的文献取得了进展”。
“地理集中”定义了产业集群的一个关键而鲜明的基本性质。
产业由地区上特定的众多公司集聚而成,他们通常有共同市场、,有着共同的供应商,交易对象,教育机构和其它像知识及信息一样无形的东西,同样地,他们也面临相似的机会和威胁。
在全球产业集群有许多种发展模式。
比如美国加州的硅谷和马萨诸塞州的128鲁特都是知名的产业集群。
前者以微电子、生物技术、和风险资本市场而闻名,而后者则是以软件、计算机和通讯硬件享誉天下[4]。
外文翻译原文及配套译文
Business process re-engineering –saviour or just another fad?One UK health care perspectiveAnjali PatwardhanHealth Service Management Centre,Birmingham,UK,and Dhruv Patwardhan University of Newcastle,Newcastle upon Tyne,UKAbstractPurpose –Pressure to change is politically driven owing to escalating healthcare costs and an emphasis on efficiency gains,value for money and improved performance proof in terms of productivity and recently to some extent by demands from less satisfied patients and stakeholders.In a background of newly immerging expensive techniques and drugs,there is an increasing consumer expectation,i.e.quality services.At the same time,health system managers and practitioners are finding it difficult to cope with demand and quality expectations.Clinicians are frustrated because they are not recognised for their contribution.Managers are frustrated because meaningful dialogue with clinicians is lacking,which has intensified the need for change to a more efficient system that satisfies all arguments about cost effectiveness and sustainable quality services.Various strategies,originally developed by management quality “gurus”for engineering industries,have been applied to health industries with variable success,which largely depends on the type of health care system to which they are applied.Design/methodology/approach –Business process re-engineering is examined as a quality management tool using past and recent publications.Findings –The paper finds that applying business process re-engineering in the right circumstances and selected settings for quality improvement is critical for its success.It is certainly “not for everybody”.Originality/value –The paper provides a critical appraisal of business process re-engineering experiences in UK healthcare.Lessons learned regarding selecting organisations and agreeing realistic expectations are addressed.Business process re-engineering has been evaluated and reviewed since 1987in US managed health care,with no clear lessons learned possibly because unit selection and simultaneous comparison between two units virtually performing at opposite ends has never been done before.Two UK pilot studies,however,add useful insights.Keywords Business process re-engineering,Total quality management,Continuous improvement,Medical management,Health services,United KingdomPaper type ViewpointHistory of quality management in health careTo know how health care organisations became interested in industrial quality development tools and how business process re-engineering (BPR)emerged as an option,we have to go back to 1987when the Quality Improvement in Health Care National Demonstration Project (NDP)was launched as an experiment (Godfrey,n.d.).A total of 21health-care organisations participated and promised to support this study lasting eight-months.The aim was to look at the applicability of industrial quality-improvement methods to health care.Support included free consulting,The current issue and full text archive of this journal is available at/0952-6862.htmBPR –saviour or just a fad?289Received 29November 2006Revised 10February 2007Accepted 25May 2007International Journal of Health Care Quality Assurance Vol.21No.3,2008pp.289-296q Emerald Group Publishing Limited 0952-6862DOI 10.1108/09526860810868229materials,access to training courses and reviews.The funding companies included many of the USA’s leading organisations such as Corning,Ford,Hewlett-Packard,IBM and Xerox.At the final stages of the project evaluations it was clear that out of 21organisations,15health care organisations made significant progress –mainly financial and patient satisfaction gains,target and project time keeping and investment in research and development.The NDP was extended for three years,which eventuallyevolved into the Institute for Healthcare Improvement,a not-for-profit organisation –dedicated to providing health-care quality management ter,BPR emerged as an alternative for managers in organisations frustrated with slow improvements,not encompassing the whole organisation experiencing total quality management (TQM).The TQM key target was to convert an organisation’s structure,culture and services to patient/consumer rather than organisation-focused goals (Harvey and Millett,1999).Why change?Traditionally health care systems were mostly “governed”by clinicians (Shutt,2003)because patient outcomes;that is,recovery from illness,were the sole responsibility of all professionals directly involved in patient plexity and variance in health care studies reveal that outcome has many determinants;i.e.pharmacy,pathology,technical support and information technology.It was also realised that cost containment and good quality care needed teamwork,communication,time management,etc.(Shutt,2003).Sir Roy Griffiths,in the early 1980s,developed hospital general management and the greater involvement of clinicians in resource management initiatives (DHSS,1984).Today,apart from political motives,change is driven by escalating health care costs,increased demands for quality care,value for money services,patient expectation and third-party payers in managed health care systems.These intensified the need for change to more efficient health care systems.What is BPR?BPR,also known business transformation and process change management,was introduced to the business world by Frederick Taylor in his article The Principles of Scientific Management in the 1900s (wikipedia,2006).In the 1990s,Hammer and Champy (1993)introduced Reengineering the Corporation ,which gave birth to BPR.BPR is “the analysis and design of workflows and processes within and between organizations”(Devenport and Short,1990,p.11).Teng et al.(1994)on the other hand,defined BPR as critical analysis and radical redesign of existing business processes to achieve breakthrough improvements in performance measures.Hammer and Champy (1993),similarly,defined BPR as fundamentally rethinking and radically redesigning business processes to achieve dramatic improvements in critical contemporary performance measures such as cost,quality,service and speed.From a health care viewpoint,BPR is a management approach that rethinks present practices and processes in business and its interactions.It attempts to improve underlying process efficiency by applying fundamental and radical approaches by either modifying or eliminating non-value adding activities and redeveloping the process/structure/culture (McNulty and Ferlie,2000).However,in the health sector,a wide variety of patient groups make the health care service a complex project to redesign along these lines,thereby rendering changes context and time sensitive.IJHCQA 21,3290BPR key featuresHealth care’s BPR approach means starting with clean slate and rethinking services using a patient-focused approach.With the benefit of hindsight BPR identifies delays caused by unnecessary steps or potential errors that are built into processes.It is presumed that redesigning processes by removing these errors dramatically improves care quality.The BPR approach,therefore,raises expectations about dramatic results. Consequently,high returns on investment are anticipated.The process,planned strategically,is explained in Taylor’s BPR framework(wikipedia,2006): .defining BPR’s purpose and goal;.identifying requirements that meet clients’needs;.defining project scope,including appropriate activities such as process mapping;.assessing the environment using,for example,force-field analyses;.re-engineering business processes and activities;.implementing redesigned processes;and.monitoring redesign success and failure.BPR vs TQMComparing BPR with other popular quality management methods helps us to appreciate and highlight key features in a health care context(Harvey and Millett,1999).TQM or continuous quality improvement(CQI)refers to programmes and initiatives that emphasise incremental improvement in work processes and outputs over an open-ended time period.In contrast,BPR refers to discrete initiatives intended to radically redesign and improve work processes within a time frame.Some people think TQM is best suited to quality in health care improvement though it is an incremental stepwise,slow but holistic approach.In practice,TQM and BPR are customer-oriented and both encourage managers and practitioners to take a customer view point.Both are team approaches that involve process control.The TQM protagonists assume that existing health care practices and systems are principally right but improvements are needed.The BPR supporters,on the other hand,assume that health care systems and practices areflawed and need replacing.Those using TQM expect and believe in stepwise increments in performance as opposed to BPR experts who look for dramatic results.TQM aims to improve all levels for all stakeholders and at all steps,while BPR aims at specified areas only.Standardisation and supporting documentation is a TQM key point.Believing in consistent and cost-effective performance and minimising process or system defects, prevents rather than corrects problems(Field and Swift,1996).Those that use the BPR approach,on the other hand,areflexible and assume that standardisation increases process complexity(Harvey and Millett,1999).Nevertheless,BPR is a drastic change leading to staff resistance.Moreover,it is a top-down approach,so management support and commitment is vital to success.Innovation,therefore,is a risky process when used for“sick organisations”.The TQM incremental method,on the other hand,follows a gradual approach that is mostly bottom-up.It involves employees and often based on Deming’s principles that direct improvements through plan-do-study-act(PDSA)cycle.TQM,therefore,is suitable for improving quality in any organisation,although some amendments to suit context may be needed.Application in managed health care generated different results BPR–saviour or just a fad?291when dissimilar processes were applied in different scenarios.Business process re-engineering,therefore,may not suite everyone because it works better when applied to sick organisations or in fundamentally defective systems (Bashein et al.,1994).The TQM approach is about a cultural change as it is built into practices hooked on daily routines.The BPR method is a target-oriented process that is time sensitive because if not completed as planned then success may be jeopardised.The TQM primary enableris statistical process control,while in BPR it is information and technology (Harvey and Millett,1999).Advantages of applying BPR to health service quality improvementUsing BPR in the health sector was a response to frustrations amongst managers in organisations who perceived TQM’s incrementalism and ability to achieve organisation-wide change had failed.King’s College Hospital experience (Grimes,2000;Harrison et al.,1992)suggests that BPR could be best tried to achieve previously unachieved levels of efficiency in scenarios when other efforts/methods had been unsuccessful.The driving forces for change were aspirations to develop a more efficient system that satisfies consumers’demands for service quality and value for money (Bowns and McNulty,1999).At the same time,BPR makes it possible to sustain such quality without necessarily costing more,even though we know that health care costs are rising steeply.The third and most important aspiration in the King’s project was to improve professionals’job satisfaction,what they felt they always deserved.The aim was to orient health care towards and focus on patients rather than organisation needs.The BPR approach focuses on rethinking and redesigning processes from scratch,giving staff opportunities to revisit services in detail,thereby pointing out improvement areas.It strips all non-value adding and unnecessary steps from the process to make services more efficient.Although it is managed top-down and dominated by managers and leaders,decision making is done at the coal-face,thereby empowering the team.The BPR approach provides a flexible work environment,culture and work practices.It can be valuable for organisations in deep difficulties and performing poorly.In such a crisis,re-engineering may be the only way organisations can survive (Harvey and Millett,1999).Where major structural and cultural deficiencies are identified or are obvious as a poor performance cause,BPR is the best way to handle that scenario –evident from King’s College Hospital experiences (Bowns and McNulty,1999).BPR limitations in health care quality improvementWe know that BPR is a top-down approach that staff may resist.It is cited by autonomous clinical professionals as “a brutal and inappropriate technique”(Jones,1996,p.4284).Implementing BPR in health care scenarios,where clinicians are key players,therefore,is not only difficult but also unsafe (McNulty and Ferlie,2000).Thus,BPR may lead to ownership loss and employee de-motivation because they are not involved in planning and change management.Generally,change processes are less-well understood by employees (Jones,1996,p.4284):Quality would seem unlikely to be forthcoming if re-engineering is imposed from the top down in a rigid and mechanistic fashion ...If organizational change is to be effective and sustainable,this will also require the active engagement of,and learning by,employees rather than grudging compliance with management diktat.IJHCQA 21,3292Quality improvement in European public services elaborated health care TQM and BPR as quality improvement tools.It was acknowledged that many business approaches to quality improvement,including TQM and re-engineering,failed to take account of health care’s complexity and the nature of professionalised knowledge.The language and values used in most of these projects were alien to clinicians and so were rejected as management fads.It seems that BPR requires massive culture and structure change if it is to improve quality of the same magnitude.It may be that radical overnight transformation may sound impressive but unrealistic.Structural and cultural change needs time to develop,be accepted and absorbed at all levels, particularly in health care settings.In short,BPR is a high-cost and high-risk project. Seventy-percent of all industries could not achieve their targets–a BPR success rate around30per cent.In the health care sector,on the other hand,from the literature we reviewed,there is no successfigure available.BPR carries an unrealistic scope and expectation most of the time,which may be a reason for its70per cent failure rate.Its top-down nature and success depends on sustained management commitment and inspirational leadership,which is not easily measured and may not be available up to the threshold needed.BPR may make only a unit change in time.To be meaningful,it needs to be followed by a CQI exercise.Once changes are brought about,BPR-based change needs CQI projects to have sustained results.It is always contested that BPR does not take account of human processes–evident from Jones’(1996,p.4284) quotation:Such a perspective is seen as promoting the idea that you can design a perfect process, implement it exactly as you planned and the organizational machine will carry it out faultlessly.Setting on one side questions about the reliability of this whole process,it is evident that BPR neglects the important role of human creativity in making process work. As we raised earlier,BPR usually innovates one process at a time rather than a whole organisation approach.The process that is changed,therefore,might not have an effect on overall organisational performance that can be measured especially those perceived by consumers.In other words,BPR may have a drastic effect on one specific process but none or very little on total organisational performance.A simple illustration for improving inpatient admissions shows that BPR alone cannot improve services.There will be need also to improve day care,outpatient,primary care and emergency services. All have an effect on an organisation’s inpatient services because they are interlinked and interdependent.Moreover,BPR’s effect can be difficult to assess in this context since NHS organisations lack specific measures(Bowns and McNulty,1999).The extent to which BPR is applicable to health care systemsThe UK BPR health care experience comes from two centrally funded pilot studies:(1)King’s College Hospital,London(KCH);and(2)Leicester Royal Infirmary(LRI).The KCH project was evaluated by a Brunel team(Packwood et al.,1998;Grimes,2000) and the LRI scheme by Sheffield and Warwick(Bowns and McNulty,1999).Employees in these organisations shared their BPR experiences during evaluation.Consequently, both studies generated interesting and valuablefindings as they highlighted to what extent BPR could be applied to health care systems.However,the two hospitals were BPR–saviour or just a fad?293extremes,i.e.KCH was a “sick”unit at the time of the study.LRI,on the other hand,was one of the best teaching hospitals (McNulty and Ferlie,2000)with little scope to improve.At the end of the pilot studies it was evident from reports that both hospitals could not reach expectations especially the drastic changes and improvements anticipated at the beginning of the BPR projects.Both reduced waiting times and length of stay along with faster diagnostic processes.King’s,over and above theseimprovements,also made £1million savings (Grimes,2000)–attributed to “waste reduction”by process mapping followed by removing non-value adding activities and by increasing efficiency in the renewed system (Packwood et al.1998).This suggests that BPR is not for everybody and that selecting units to which BPR can be applied is important to achieve desired results.When the two trusts ran the pilot,they also continued to work on their generic and core improvement initiatives at different levels in the process and so it was difficult to attribute success to BPR alone or to assess its relative contribution to overall improvements.One approach to identify suitable sub processes for applying BPR is process mapping from “door to door”,which helps capture all the process components and applying a lean approach (Jones and Mitchell,2006,p.23).Identifying value-added activities highlights the non-value-added ones.Each non-value-added activity can be measured and analysed to assess its impact and ways to eliminate activity.Resource availability,deadline,cost,generic skills and above all,urgency to change help users select the right improvement tool.Also,as raised earlier,change management success is closely related to team morale,ownership and motivation.To achieve quality in health care services,therefore,two key staff groups –managers and clinicians,who come from different cultural backgrounds and are knowledgeable in different ways,need to work as a team.Understanding and cooperation are crucial if difficult tasks are to be accomplished (Shortell et al.1998).However,BPR’s failure to consider the human aspects of processes may make it difficult to integrate BPR into health care services.The BPR approach sounds impressive but unrealistic because soft structural and cultural change need time to develop particularly in health care settings.We believe that BPR can help to improve health services if it is meticulously planned and applied diligently.In short,even with all BPR’s limitations,it is still capable of delivering dramatic results not least because it forces staff to think from outside the scenario or process as a whole and work to deadlines (Bowns and McNulty,1999).Conclusions and recommendationsHealth care is a more complex system than any manufacturing industry.As a service provider with a major human component there are safety and efficiency issues rather than cost and efficacy,which separates health care from industry.BPR,like other single approaches to improve service quality,are likely to be unsuitable for health care (Shortell and Ferlie,2001),which is comprised of a number of sub processes.It has many stakeholders at different levels and there is wide variation in its internal customer (e.g.,fellow professionals)and external customer (i.e.patients)needs.We accept that BPR can be used as a tool for improving some sub-process or sub-unit activity.An example could be what happened in the LRI where BPR was tried as a quality improvement tool in bed management,pathology and OPD service innovation,etc.;but not applied in areas where clinician’s precision was paramount or where BPR was accepted less-well.In these areas,therefore,views on the methods’suitability forIJHCQA 21,3294quality improvements were mixed.That is,TQM and BPR ideally should always be followed by CQI methods for service improvement to be sustainable and effective.In short,quality management tools designed for industry should be applied to health services with proper selection,caution and care.ReferencesBashein,B.J.,Markus,M.L.and Riley,P.(1994),“Preconditions for BPR success:and how to prevent failures”,Information Systems Management,Vol.11No.2,pp.7-13.Bowns,I.R.and McNulty,T.(1999),Re-engineering Leicester Royal Infirmary–Executive Summary,School of Health and Related Research,University of Sheffield,Sheffield. Devenport,T.and Short,J.(1990),“The new industrial engineering information technology and BPR”,Sloan Management Review,Summer,pp.11-27.DHSS(1984),Health Services Management:Implementation of the NHS Management Inquiry, DHSS Circular HC(84)13,DHSS,London.Field,S.W.and Swift,K.G.(1996),Effecting a Quality Change:An Engineering Approach,Arnold, London.Godfrey,B.(n.d.),“Quality health care”,Quality Digest,available at:/ sep96/health.htm(accessed on15October2006).Grimes,K.(2000),Changing the Change Team,King’s College Hospital,London.Hammer,M.and Champy,J.(1993),Reengineering the Corporation:A Manifesto for Business Revolution,Harper Business Books,New York,NY.Harrison,S.,Hunter,D.,Marnoch,G.and Pollitt,C.(1992),Just Managing:Power and Culture in the NHS,Macmillan,Basingstoke.Harvey,S.and Millett,B.(1999),“OD,TQM and BPR:a comparative approach”,Australian Journal of Management and Organizational Behavior,Vol.2No.3,pp.30-42.Jones,D.and Mitchell,A.(2006),Lean Thinking for the NHS:A Report Commissioned by the NHS Confederation,pamphlet RA395.G7,NHS Confederation,London.Jones,M.(1996),“Re-engineering”,in Warner,M.(Ed.),International Encyclopedia of Business and Management,Routledge,London.McNulty,T.and Ferlie,E.(2000),Reengineering Health Care:The Complexities of Organisational Transformation,Oxford University Press,Oxford.Packwood,T.,Pollitt,C.and Roberts,S.(1998),“Good medicine?A case study of business process reengineering in a hospital”,Policy and Politics,Vol.26No.4,pp.401-15. Shortell,S.and Ferlie,E.(2001),“Improving quality of healthcare in the United Kingdom and the United States:a framework for change”,The Milbank Quarterly,Vol.79No.2,May, pp.281-315.Shortell,S.M.,Waters,T.M.and Clarke,K.W.B.(1998),“Physicians as double agents: maintaining trust in an era of multiple accountabilities”,Journal of the American Medical Association,Vol.280No.12,pp.1102-8.Shutt,J.A.(2003),“Balancing the health care scorecard”,Managed Care,September,pp.42-6. Teng,J.T.C.,Grover,V.and Fiedler,K.(1994),“Business process reengineering:charting a strategic path for the information age”,California Management Review,Vol.36No.3, pp.9-31.wikipedia(2006),“Frederick Winslow Taylor”,available at:/wiki/ Frederick_Winslow_Taylor(accessed2December2006).BPR–saviour or just a fad?295Further reading Davies,H.T.O.(2000),“Organizational culture and quality of health care”,Quality in Health Care ,Vol.9No.2,pp.111-9.Malhotra,Y.(1998),“Business process redesign:an overview”,IEEE Engineering Management Review ,Vol.26No.3,pp.214-25.Pollitt,C.(1996),“Business approaches to quality improvement:why are they hard for the NHS toswallow?”,Quality in Health Care ,Vol.5No.2,pp.104-10.Raymond,L.,Bergeron, F.and Rivard,S.(1980),“Determinants of business processreengineering success in small and large enterprises:an empirical study in the Canadian context”,Journal of Small Business Management ,Vol.36,pp.72-85.Corresponding authorAnjali Patwardhan can be contacted at:doctoranjali@IJHCQA 21,3296To purchase reprints of this article please e-mail:reprints@ Or visit our web site for further details:/reprints。
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(完整版)外文翻译外文文件原稿和译文原稿logistics distribution center location factors:(1)the goods distribution and quantity. This is the distribution center and distribution of the object, such as goods source and the future of distribution, history and current and future forecast and development, etc. Distribution center should as far as possible and producer form in the area and distribution short optimization. The quantity of goods is along with the growth of the size distribution and constant growth. Goods higher growth rate, the more demand distribution center location is reasonable and reducing conveying process unnecessary waste.(2)transportation conditions. The location of logistics distribution center should be close to the transportation hub, and to form the logistics distribution center in the process of a proper nodes. In the conditional, distribution center should be as close to the railway station, port and highway.(3)land conditions. Logistics distribution center covers an area of land in increasingly expensive problem today is more and more important. Is the use of the existing land or land again? Land price? Whether to conform to the requirements of the plan for the government, and so on, in the construction distribution center have considered.(4)commodities flow. Enterprise production of consumer goods as the population shift and change, should according to enterprise's better distribution system positioning. Meanwhile, industrial products market will transfer change, in order to determine the raw materials and semi-finished products of commodities such as change of flow in the location of logistics distribution center should be considered when the flow of the specific conditions of the relevant goods.(5)other factors. Such as labor, transportation and service convenience degree, investment restrictions, etc.(完整版)外文翻译How to reduce logistics cost,enhance the adaptive capacity and strain capacityof distribution center is a key research question of agricultural product logisticsdistribution center.At present,most of the research on logistics cost concentrates offtheoretical analysis of direct factors of logistics cost, and solves the problem ofover-high logistics Cost mainly by direct channel solution . This research stresseson the view of how to loeate distribution center, analyzes the influence of locatingdistribution center on logistics cost .and finds one kind of simple and easy locationmethod by carrying on the location analysis of distribution center through computermodeling and the application of Exeel.So the location of agricultural productlogistics distribution center can be achieved scientifically and reasonably, which willattain the goal of reducing logistics cost, and have a decision.making supportfunction to the logisties facilities and planning of agricultural product.The agricultural product logistics distribution center deals with dozens andeven hundreds of clients every day, and transactions are made in high-frequency. Ifthe distribution center is far away from other distribution points,the moving andtransporting of materials and the collecting of operational data is inconvenient andcostly. costly.The modernization of agricultural product logistics s distribution center is acomplex engineering system, not only involves logistics technology, informationtechnology, but also logistics management ideas and its methods,in particular thespecifying of strategic location and business model is essential for the constructing ofdistribution center. How to reduce logistics cost ,enhance the adaptive capacity andstrain capacity of distribution center is a key research question of agricultural productlogistics distribution center. The so— called logistics costs refers to the expendituresummation of manpower, material and financial resources in the moving process of thegoods.such as loading and unloading,conveying,transport,storage,circulating,processing, information processing and other segments. In a word。
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外文文献翻译原文Analysis of Con tin uous Prestressed Concrete BeamsChris BurgoyneMarch 26, 20051、IntroductionThis conference is devoted to the development of structural analysis rather than the strength of materials, but the effective use of prestressed concrete relies on an appropriate combination of structural analysis techniques with knowledge of the material behaviour. Design of prestressed concrete structures is usually left to specialists; the unwary will either make mistakes or spend inordinate time trying to extract a solution from the various equations.There are a number of fundamental differences between the behaviour of prestressed concrete and that of other materials. Structures are not unstressed when unloaded; the design space of feasible solutions is totally bounded;in hyperstatic structures, various states of self-stress can be induced by altering the cable profile, and all of these factors get influenced by creep and thermal effects. How were these problems recognised and how have they been tackled?Ever since the development of reinforced concrete by Hennebique at the end of the 19th century (Cusack 1984), it was recognised that steel and concrete could be more effectively combined if the steel was pretensioned, putting the concrete into compression. Cracking could be reduced, if not prevented altogether, which would increase stiffness and improve durability. Early attempts all failed because the initial prestress soon vanished, leaving the structure to be- have as though it was reinforced; good descriptions of these attempts are given by Leonhardt (1964) and Abeles (1964).It was Freyssineti’s observations of the sagging of the shallow arches on three bridges that he had just completed in 1927 over the River Allier near Vichy which led directly to prestressed concrete (Freyssinet 1956). Only the bridge at Boutiron survived WWII (Fig 1). Hitherto, it had been assumed that concrete had a Young’s modulus which remained fixed, but he recognised that the de- ferred strains due to creep explained why the prestress had been lost in the early trials. Freyssinet (Fig. 2) also correctly reasoned that high tensile steel had to be used, so that some prestress would remain after the creep had occurred, and alsothat high quality concrete should be used, since this minimised the total amount of creep. The history of Freyssineti’s early prestressed concrete work is written elsewhereFigure1:Boutiron Bridge,Vic h yFigure 2: Eugen FreyssinetAt about the same time work was underway on creep at the BRE laboratory in England ((Glanville 1930) and (1933)). It is debatable which man should be given credit for the discovery of creep but Freyssinet clearly gets the credit for successfully using the knowledge to prestress concrete.There are still problems associated with understanding how prestressed concrete works, partly because there is more than one way of thinking about it. These different philosophies are to some extent contradictory, and certainly confusing to the young engineer. It is also reflected, to a certain extent, in the various codes of practice.Permissible stress design philosophy sees prestressed concrete as a way of avoiding cracking by eliminating tensile stresses; the objective is for sufficient compression to remain after creep losses. Untensionedreinforcement, which attracts prestress due to creep, is anathema. This philosophy derives directly from Freyssinet’s logic and is primarily a working stress concept.Ultimate strength philosophy sees prestressing as a way of utilising high tensile steel as reinforcement. High strength steels have high elastic strain capacity, which could not be utilised when used as reinforcement; if the steel is pretensioned, much of that strain capacity is taken out before bonding the steel to the concrete. Structures designed this way are normally designed to be in compression everywhere under permanent loads, but allowed to crack under high live load. The idea derives directly from the work of Dischinger (1936) and his work on the bridge at Aue in 1939 (Schonberg and Fichter 1939), as well as that of Finsterwalder (1939). It is primarily an ultimate load concept. The idea of partial prestressing derives from these ideas.The Load-Balancing philosophy, introduced by T.Y. Lin, uses prestressing to counter the effect of the permanent loads (Lin 1963). The sag of the cables causes an upward force on the beam, which counteracts the load on the beam. Clearly, only one load can be balanced, but if this is taken as the total dead weight, then under that load the beam will perceive only the net axial prestress and will have no tendency to creep up or down.These three philosophies all have their champions, and heated debates take place between them as to which is the most fundamental.2、Section designFrom the outset it was recognised that prestressed concrete has to be checked at both the working load and the ultimate load. For steel structures, and those made from reinforced concrete, there is a fairly direct relationship between the load capacity under an allowable stress design, and that at the ultimate load under an ultimate strength design. Older codes were based on permissible stresses at the working load; new codes use moment capacities at the ultimate load. Different load factors are used in the two codes, but a structure which passes one code is likely to be acceptable under the other.For prestressed concrete, those ideas do not hold, since the structure is highly stressed, even when unloaded. A small increase of load can cause some stress limits to be breached, while a large increase in load might be needed to cross other limits. The designer has considerable freedom to vary both the working load and ultimate load capacities independently; both need to be checked.A designer normally has to check the tensile and compressive stresses, in both the top and bottom fibre of the section, for every load case. The critical sections are normally, but not always, the mid-span and the sections over piers but other sections may become critical ,when the cable profile has to be determined.The stresses at any position are made up of three components, one of which normally has a different sign from the other two; consistency of sign convention is essential.If P is the prestressing force and e its eccentricity, A and Z are the area of the cross-section and its elastic section modulus, while M is the applied moment, then where ft and fc are the permissible stresses in tension and compression.c e t f ZM Z P A P f ≤-+≤Thus, for any combination of P and M , the designer already has four in- equalities to deal with.The prestressing force differs over time, due to creep losses, and a designer isusually faced with at least three combinations of prestressing force and moment;• the applied moment at the time the prestress is first applied, before creep losses occur,• the maximum applied moment after creep losses, and• the minimum applied moment after creep losses.Figure 4: Gustave MagnelOther combinations may be needed in more complex cases. There are at least twelve inequalities that have to be satisfied at any cross-section, but since an I-section can be defined by six variables, and two are needed to define the prestress, the problem is over-specified and it is not immediately obvious which conditions are superfluous. In the hands of inexperienced engineers, the design process can be very long-winded. However, it is possible to separate out the design of the cross-section from the design of the prestress. By considering pairs of stress limits on the same fibre, but for different load cases, the effects of the prestress can be eliminated, leaving expressions of the form:rangestress e Perm issibl Range Mom entZ These inequalities, which can be evaluated exhaustively with little difficulty, allow the minimum size of the cross-section to be determined.Once a suitable cross-section has been found, the prestress can be designed using a construction due to Magnel (Fig.4). The stress limits can all be rearranged into the form:()M fZ PA Z e ++-≤1 By plotting these on a diagram of eccentricity versus the reciprocal of the prestressing force, a series of bound lines will be formed. Provided the inequalities (2) are satisfied, these bound lines will always leave a zone showing all feasible combinations of P and e. The most economical design, using the minimum prestress, usually lies on the right hand side of the diagram, where the design is limited by the permissible tensile stresses.Plotting the eccentricity on the vertical axis allows direct comparison with the crosssection, as shown in Fig. 5. Inequalities (3) make no reference to the physical dimensions of the structure, but these practical cover limits can be shown as wellA good designer knows how changes to the design and the loadings alter the Magnel diagram. Changing both the maximum andminimum bending moments, but keeping the range the same, raises and lowers the feasible region. If the moments become more sagging the feasible region gets lower in the beam.In general, as spans increase, the dead load moments increase in proportion to the live load. A stage will be reached where the economic point (A on Fig.5) moves outside the physical limits of the beam; Guyon (1951a) denoted the limiting condition as the critical span. Shorter spans will be governed by tensile stresses in the two extreme fibres, while longer spans will be governed by the limiting eccentricity and tensile stresses in the bottom fibre. However, it does not take a large increase in moment ,at which point compressive stresses will govern in the bottom fibre under maximum moment.Only when much longer spans are required, and the feasible region moves as far down as possible, does the structure become governed by compressive stresses in both fibres.3、Continuous beamsThe design of statically determinate beams is relatively straightforward; the engineer can work on the basis of the design of individual cross-sections, as outlined above. A number of complications arise when the structure is indeterminate which means that the designer has to consider, not only a critical section,but also the behaviour of the beam as a whole. These are due to the interaction of a number of factors, such as Creep, Temperature effects and Construction Sequence effects. It is the development of these ideas whichforms the core of this paper. The problems of continuity were addressed at a conference in London (Andrew and Witt 1951). The basic principles, and nomenclature, were already in use, but to modern eyes concentration on hand analysis techniques was unusual, and one of the principle concerns seems to have been the difficulty of estimating losses of prestressing force.3.1 Secondary MomentsA prestressing cable in a beam causes the structure to deflect. Unlike the statically determinate beam, where this motion is unrestrained, the movement causes a redistribution of the support reactions which in turn induces additional moments. These are often termed Secondary Moments, but they are not always small, or Parasitic Moments, but they are not always bad.Freyssinet’s bridge across the Marne at Luzancy, started in 1941 but not completed until 1946, is often thought of as a simply supported beam, but it was actually built as a two-hinged arch (Harris 1986), with support reactions adjusted by means of flat jacks and wedges which were later grouted-in (Fig.6). The same principles were applied in the later and larger beams built over the same river.Magnel built the first indeterminate beam bridge at Sclayn, in Belgium (Fig.7) in 1946. The cables are virtually straight, but he adjusted the deck profile so that the cables were close to the soffit near mid-span. Even with straight cables the sagging secondary momentsare large; about 50% of the hogging moment at the central support caused by dead and live load.The secondary moments cannot be found until the profile is known but the cablecannot be designed until the secondary moments are known. Guyon (1951b) introduced the concept of the concordant profile, which is a profile that causes no secondary moments; es and ep thus coincide. Any line of thrust is itself a concordant profile.The designer is then faced with a slightly simpler problem; a cable profile has to be chosen which not only satisfies the eccentricity limits (3) but is also concordant. That in itself is not a trivial operation, but is helped by the fact that the bending moment diagram that results from any load applied to a beam will itself be a concordant profile for a cable of constant force. Such loads are termed notional loads to distinguish them from the real loads on the structure. Superposition can be used to progressively build up a set of notional loads whose bending moment diagram gives the desired concordant profile.3.2 Temperature effectsTemperature variations apply to all structures but the effect on prestressed concrete beams can be more pronounced than in other structures. The temperature profile through the depth of a beam (Emerson 1973) can be split into three components for the purposes of calculation (Hambly 1991). The first causes a longitudinal expansion, which is normally released by the articulation of the structure; the second causes curvature which leads to deflection in all beams and reactant moments in continuous beams, while the third causes a set of self-equilibrating set of stresses across the cross-section.The reactant moments can be calculated and allowed-for, but it is the self- equilibrating stresses that cause the main problems for prestressed concrete beams. These beams normally have high thermal mass which means that daily temperature variations do not penetrate to the core of the structure. The result is a very non-uniform temperature distribution across the depth which in turn leads to significant self-equilibrating stresses. If the core of the structure is warm, while the surface is cool, such as at night, then quite large tensile stresses can be developed on the top and bottom surfaces. However, they only penetrate a very short distance into the concrete and the potential crack width is very small. It can be very expensive to overcome the tensile stress by changing the section or the prestress。
本科毕业设计(论文)外文翻译译文
本科毕业设计(论文)外文翻译译文学生姓名:院(系):油气资源学院专业班级:物探0502指导教师:完成日期:年月日地震驱动评价与发展:以玻利维亚冲积盆地的研究为例起止页码:1099——1108出版日期:NOVEMBER 2005THE LEADING EDGE出版单位:PanYAmericanYEnergyvBuenosYAiresvYArgentinaJPYBLANGYvYBPYExplorationvYHoustonvYUSAJ.C.YCORDOVAandYE.YMARTINEZvYChacoYS.A.vYSantaYCruzvYBolivia 通过整合多种地球物理地质技术,在玻利维亚冲积盆地,我们可以减少许多与白垩纪储集层勘探有关的地质技术风险。
通过对这些远景区进行成功钻探我们可以验证我们的解释。
这些方法包括盆地模拟,联井及地震叠前同时反演,岩石性质及地震属性解释,A VO/A V A,水平地震同相轴,光谱分解。
联合解释能够得到构造和沉积模式的微笑校正。
迄今为止,在新区有七口井已经进行了成功钻探。
基质和区域地质。
Tarija/Chaco盆地的subandean 褶皱和冲断带山麓的中部和南部,部分扩展到玻利维亚的Boomerange地区经历了集中的成功的开采。
许多深大的泥盆纪气田已经被发现,目前正在生产。
另外在山麓发现的规模较小较浅的天然气和凝析气田和大的油田进行价格竞争,如果他们能产出较快的油流而且成本低。
最近发现气田就是这种情况。
接下来,我们赋予Aguja的虚假名字就是为了讲述这些油田的成功例子。
图1 Aguja油田位于玻利维亚中部Chaco盆地的西北角。
基底构造图显示了Isarzama背斜的相对位置。
地层柱状图显示了主要的储集层和源岩。
该油田在Trija和冲积盆地附近的益背斜基底上,该背斜将油田和Ben i盆地分开(图1),圈闭类型是上盘背斜,它存在于连续冲断层上,Aguja有两个主要结构:Aguja中部和Aguja Norte,通过重要的转换压缩断层将较早开发的“Sur”油田分开Yantata Centro结构是一个三路闭合对低角度逆冲断层并伴随有小的摆幅。
仓储物流外文文献翻译中英文原文及译文2023-2023
仓储物流外文文献翻译中英文原文及译文2023-2023原文1:The Current Trends in Warehouse Management and LogisticsWarehouse management is an essential component of any supply chain and plays a crucial role in the overall efficiency and effectiveness of logistics operations. With the rapid advancement of technology and changing customer demands, the field of warehouse management and logistics has seen several trends emerge in recent years.One significant trend is the increasing adoption of automation and robotics in warehouse operations. Automated systems such as conveyor belts, robotic pickers, and driverless vehicles have revolutionized the way warehouses function. These technologies not only improve accuracy and speed but also reduce labor costs and increase safety.Another trend is the implementation of real-time tracking and visibility systems. Through the use of RFID (radio-frequency identification) tags and GPS (global positioning system) technology, warehouse managers can monitor the movement of goods throughout the entire supply chain. This level of visibility enables better inventory management, reduces stockouts, and improves customer satisfaction.Additionally, there is a growing focus on sustainability in warehouse management and logistics. Many companies are implementing environmentally friendly practices such as energy-efficient lighting, recycling programs, and alternativetransportation methods. These initiatives not only contribute to reducing carbon emissions but also result in cost savings and improved brand image.Furthermore, artificial intelligence (AI) and machine learning have become integral parts of warehouse management. AI-powered systems can analyze large volumes of data to optimize inventory levels, forecast demand accurately, and improve operational efficiency. Machine learning algorithms can also identify patterns and anomalies, enabling proactive maintenance and minimizing downtime.In conclusion, warehouse management and logistics are continuously evolving fields, driven by technological advancements and changing market demands. The trends discussed in this article highlight the importance of adopting innovative solutions to enhance efficiency, visibility, sustainability, and overall performance in warehouse operations.译文1:仓储物流管理的当前趋势仓储物流管理是任何供应链的重要组成部分,并在物流运营的整体效率和效力中发挥着至关重要的作用。
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外文翻译译文工业控制系统和协同控制系统当今的控制系统被广泛运用于许多领域。
从单纯的工业控制系统到协同控制系统(CCS),控制系统不停变化,不断升级,现在则趋向于家庭控制系统,而它则是这两者的变种。
被应用的控制系统的种类取决于技术要求。
而且,实践表明,经济和社会因素也对此很重要。
任何决定都有它的优缺点。
工业控制要求可靠性,完整的文献记载和技术支持。
经济因素使决定趋向于协同工具。
能够亲自接触源码并可以更快速地解决问题是家庭控制系统的要求。
多年的操作经验表明哪个解决方法是最主要的不重要,重要的是哪个可行。
由于异类系统的存在,针对不同协议的支持也是至关重要的。
本文介绍工业控制系统,PlC controlled turn key系统,和CCS工具,以及它们之间的操作。
引言:80年代早期,随着为HERA(Hadron-Elektron-Ring-Anlage)加速器安装低温控制系统,德国电子同步加速器研究所普遍开始研究过程控制。
这项新技术是必需的,因为但是现有的硬件没有能力来处理标准过程控制信号,如4至20毫安的电流输入和输出信号。
而且软件无法在0.1秒的稳定重复率下运行PID控制回路。
此外,在实现对复杂的低温冷藏系统的开闭过程中,频率项目显得尤为重要。
有必要增加接口解决总线问题并增加运算能力,以便于低温控制。
因为已安装的D / 3系统[1] 只提供了与多总线板串行连接,以实现DMA与VME的连接并用其模拟多总线板的功能。
温度转换器的计算功能来自一个摩托罗拉MVME 167 CPU和总线适配器,以及一个MVME 162 CPU。
其操作系统是VxWorks,而应用程序是EPICS。
由于对它的应用相当成功,其还被运用于正在寻找一个通用的解决方案以监督他们的分布式PLC的公共事业管理。
德国电子同步加速器研究所对过程管理系统的筛选集散控制系统(D/ 3):市场调查表明:来自GSE的D / 3系统被HERA低温冷藏工厂选中。
因为集散控制系统(D/ 3)的特性,所以这决定很不错。
在展示端和I / O端扩展此系统的可能将有助于解决日益增加的HERA试验控制的要求。
制约系统的大小的因素不是I / O的总数,通信网络的畅通与否。
而通信网络的畅通与否取决于不存档的数据总量,不取决于报警系统中配置的数据。
拥有DCS特点(Cube)的SCADA系统:相对于Y2K问题促使我们寻找一个升级版或者代替版来代替现有的系统而言,以上提到的D / 3系统有一些硬编码的限制。
由于急需给Orsi公司提供他们的产品,Cube开始起作用了[2]。
该项目包括安装功能的完全更换。
这包括D / 3,以及德国电子同步加速器研究所的集成总线SEDAC和VME的温度转换器。
该项目很有前景。
但是因为HERA试验原定时间是有限制的,所以技术问题和组织问题也迫使计划提前。
在供应商网站上的最后验收测试又出现了戏剧性的性能问题。
有两个因素引起了这些问题。
第一个跟低估在1赫兹运行的6级温度转换器的CPU负荷有关。
第二个由现有D / 3系统复杂的功能造成的额外负荷引起的。
每个数字和模拟输入和输出通道在D / 3系统里的自身报警限值也被低估了。
所有的附加功能都必须添加进去。
最后,所有网络负载的报警限值,尤其是SCADA 系统,也促使网络生成了限制。
最后,与Orsi公司的合同被取消了。
升级的D / 3系统是唯一可能的解决办法。
在2003年3月,此系统最后被付诸实践。
现在,相比“纯粹”SCADA系统的异质环境,Cube有同质配置环境的优势。
SCADA(PVSS -Ⅱ):在HERA加速器上的H1实验中,实验人员为升级他们的低速控制系统,决定使用PVSS -Ⅱ。
现有的系统是由H1合作组的几名成员开发的,而现在却难以维持了。
在CERN由联合控制项目[4]进行的广泛调查促使他们做出使用PVSS 作为代替品的决定。
PVSS是一个“纯粹”的监控和数据采集系统(SCADA系统)。
其核心元素叫做事件管理器。
它收集的数据主要是由I/ O设备提供。
它还提供附加的管理服务,如:控制经理,数据库管理,用户界面,API经理以及在建的HTTP服务器。
该PVSS脚本库允许执行复杂的序列以及复杂的图形。
相比其他SCADA系统PVSS带有一个基本特点:它提供了API给设备的数据。
SCADA系统的一个主要缺点是其中的两个数据库,一个为PLC’s服务,另一个为SCADA系统服务,这两个数据库必须维持。
集成环境将努力克服这个限制。
EPICS:在德国电子同步加速器研究所,EPICS从问题解决系统演化成了全集成控制系统。
从成为低温控制系统的数据收集器和数量控制器,EPICS成为了德国电子同步加速器研究所公用事业集团使用的核心系统。
此外,通过Industry Pack(IP)模块的手段,它还能运用于通过VME板卡的任何数据。
EPICS通过其完整的功能,运用于没有由D / 3系统控制的低温冷藏系统。
所有大约50个输入输出控制器运作大约25000业务处理记录。
作为一个SCADA系统的EPICS:该公共事业组(水,电,压缩空气,加热和调温)使用各种散布在整个德国电子同步加速器研究所网站上的PLC。
IOC向客户提供接口并采集数据。
此外,如通道归档和图形显示(dm2k)会被使用。
默认名决议和目录服务器(域名服务器)用于连接在TCP客户端和服务器应用程序。
所有这些都是基本的SCADA 功能。
所有的配置文件(图形工具,报警处理程序和归档)提供了一种灵活的配置方案。
德国电子同步加速器研究所公用事业集团已制定了一套工具来创建IOC 数据库和配置文件。
这样,控制组提供的服务保持EPICS工具,而用户可以精力集中在被控制的设备上了。
作为一个DCS系统的EPICS:作为SCADA系统的基本组成部分,EPICS还提供完整的输入输出控制器(IOC)。
IOC提供所有功能DCS系统要求,如:实施每个记录的标准的属性;执行每个记录时的报警检查过程;控制记录,如PID。
灵活的命名方案,默认的显示和每个记录的报警属性缓和了运作工具和IOC之间的连接。
灵活的数据采集模式,支持调查模式以及发布订阅模式。
后者大大降低了信息拥堵的情况。
PLC’s:PLC’s同样提供丰富的功能,因为以前它是独一无二的控制系统。
此外,定期执行一个确定功能的基本特征也让他们通过以太网通信,包括内置的HTTP 服务器和不同集合的通讯方案。
除了通信处理器,显示器能和PLC’s连接。
智能I / O:I / O设备上的新发展允许在更小的群体中集群I / O并把这些集群I / O渠道链接到控制系统。
PLC’s对于分布式I / O已不再重要。
PLC’s和智能I / O子系统的差别正在消失。
功能持续不断的问题,如为什么控制系统的加速器和其他高度专业化的设备联合协同发展。
但是,在极少数情况下,只通过商业的立场时难以回答的。
在这里,我们试图总结不同控制方法的基本功能。
前端控制器:对控制系统的核心要素之一,是前端控制器。
PLC’s可用于实施控制功能的设备。
它的缺点就是复杂,难以达到控制属性。
例如确定通信协议和最后在显示、报警和归档方案,一个控件的所有属性像P,I和D参数,还有报警限制及其他附加的属性必须得到解决。
另外,这些嵌入式属性修改是很难寻觅,因为其中涉及两个或两个以上轨道系统这可能是一个有力的论据是,为什么控制回路主要实施在IOC层面,而不是PLC’s层面。
I / O和控制回路复杂的控制算法和控制回路和域名DCS控制系统一样。
对显示和控件的属性的支持是必不可少的。
频率/国家计划在控制系统中,频率程序可以运行任何处理器。
运行时环境取决于相关代码。
控制系统程序直接履行运行前端处理器的监控。
为复杂的启动和关闭处理程序设立的频率程序也可以运行工作站。
国家机器的基本功能在IEC 61131中得到了落实。
编码发电机可以产生C代码。
硬件支持对现场总线和起源于I / O的Ethernet的支持是为SCADA系统服务的一个基本功能。
所有SCADA系统在市场商业运作中是可行的。
配置特定驱动器和数据转换器的集成硬件在商业环境中是一个难点。
开放API或脚本支持有时有助于整合用户的硬件。
如果不向控制系统提供这些工具,就很难整合客户硬件。
新的工业标准,如OPC,和OPC设施联系,还和控制系统之间互相联系。
这种功能的基本条件是强调操作系统。
在这种情况下,OPC更趋向于微软的DCOM标准。
基于控制系统的UNIX很难互相连接。
只有支持多平台的控制系统可以在异构环境中发挥主要作用。
由于为客户或专业硬件的支持有限,所以新的控制系统有理由得到发展。
显示和操作除了前后系统,操作接口在控制系统的兼容过程中有重要的作用。
因为个人呢工具由不同的团队开发,所以协作实现的工具包可能变动。
1图形天气显示是任何控制系统的广告招牌。
商业天气显示也有着丰富的功能和许多特色。
开始使用所有这些特征,所有这些功能的使用人会发现,所有个别属性的图形对象要分别指定。
一个输入通道不只由物业的价值决定的,而且更由包括像展出范围和报警值决定的。
一再分辨所有性能可能是个非常乏味的工作。
有些系统产生图形原型对象。
这些原型图形或模板很复杂,但需要一个专家来生产。
DCS或自定义天气显示程序使用常见的I / O点属性集。
这个预定义的命名方案填写标准的属性值,因此只需要进入记录,或设备名称进入配置工具。
2 报警系统警报可以很好的区分不同的控制系统架构。
实现I / O对象的这些系统在前后端电脑提供警报检查。
只能读懂I / O点的系统在I / O处理过程中添加了警报检查。
I / O对象途径在前后端系统的本土项目语言安插了警报检测。
,I / O点导向系统通常要在他们的脚文本语言中实现这种功能。
这是通常效率较低且容易出错,因为所有属性必须被单独配置,这导致了一系列特性。
不仅为每个I / O 点的错误状态结束是个人的I / O点,但报警限值和每个报警的轻重,应当限制定义为I / O点,如果它希望能够改变运行值。
这种影响在SCADA和DCS系统之间也形成了影响。
SCADA系统本就读不懂报警系统。
DCS系统的优势在于管理人员既可以登记警报状态,从而提前得到信息,控制蔓延到在控制系统周围的变化。
后一种情况是唯一可能的系统。
3 趋势和归档趋势已成为控制系统架构中的一个重要的业务。
趋势是必要的跟踪误差条件。
实现的数据存储有能力储存完整控制目标,大部分的趋势工具标量数据存档。
附加特性如条件趋向或相关情节在个人实施起了影响。
4编程接口关于开放编程接口,PLC’s和DCS系统有相同策略。
他们运行可靠,因为他们没有办法整合可定制的合作去干涉内部处理。
因此,客户定制精品,这个极其昂贵的。
由于SCADA系统必须能够与多种I / O子系统连接已经在API上建立了I / O子系统以整合自定义功能。