外文文献及译文

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。

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。

国际服务贸易外文翻译文献(含：英文原文及中文译文)文献出处：《World Development》，2015，12（1）：35-44.英文原文The research of international service trade and economic growth theoryChakraborty Kavin1 IntroductionThe study of the relation between international trade and economic growth is one of the most active issues. Since 1980s, the world has been in transition from national economy orientating towards natural resources and manufacturing industry to global and regional economy orientating towards information resources and service industry. After the signature of GA TS in1994, the institutional arrangements on liberalizing service trade result in a world-wide involvement division and exchanges of service trade, and it is undoubtedly that the positive interaction between service trade and investment leads to economic growth. But the theoretical research on service trade lags behind practice.Is it a statistic phenomenon or a universal rule of economic growth? To approach the above two issues from theoretical and empirical perspective is of great value to policy-making.For the proposition of that "International service trade will drive economic growth". Theoretical analysis shows that although service tradeis not a direct interpretative variable to economic growth, it can effect economic growth indirectly through other growing factors and technology upgrade, but the ways and mechanisms are different in different stages. In a certain stage of economic development, service trade (including investment) will have static and dynamic effect on factors supply and technology upgrade in one county, which will lead to the domestic alteration of resources condition structure. It is the enterprises that select industry structure, technology structure and trade structure according to dynamic alteration way of comparative technology structure and trade structure, which will ultimately promote evolution of economic growth gradually. So far as operational mechanism of service trade and investment is concerned, service trade affects factors supply in one country by physical capital accumulating effect, human capital effect, technology upgrade effect, institutional transition effect, employment effect and externality of technology, then influences the upgrade of industrial structure, the upgrade of technological structure and the transition of mode of economic growth. It is obvious that dynamic effect is greater than static effect; that external effect is playing more important role than internal effect; and that technology spillover effect of foreign direct investment in service industry is greater than that of service trade in a narrow sense (including across-border supply, consumption abroad and movement of natural person).For the research of mechanism about how service trade drive economic growth. Firstly, the paper verifies the causality between service trade and economic growths concerning different economic bodies and the representative countries. The results show that there are causalities between international service trade and economic growth in the whole world, in the developed countries, in the US and in china. In the developing countries, service trade is the Granger cause of economic growth; In the whole world and the developing countries, economic growth is the Granger cause of service trade; In the US, service export is the Granger cause of economic growth, and economic growth is the Granger cause of service import. On this basis, it is concluded that the opening of service industry will benefit economic growth in one country. Secondly, in order to explore on how the service trade and investment act on economic growth, empirical studies are employed to explain the case of US and that of China. The results show that the routes by which service trade affects economic growth in the US can be rowed as follows from more significant to less: employment effect, human capital effect, physical capital effect, technology effect, institution effect. The results of empirical analysis of China can be summarized that: the routes by which service export affects economic growth can be rowed as follows: employment effect, physical capital effect, institution effect, human capital effect, technology effect; the routs by which service import affectseconomic growth can be rowed as follows: technology effect, institution effect, employment effect, human capital effect, physical capital effect; the routes by which FDI in service affects economic growth can be rowed as follows: technology effect, human capital effect, institution effect, employment effect, physical capital effect. Moreover, the effect of FDI in service is stronger than service import, and the effect of service import is stronger than service export.According to the empirical test in this paper, the conclusion can be drawn as follows: service trade in a narrow sense will have static and dynamic effects on factor supply in one country through import and export of service, FDI in service industry is one of the most important cross-border transactions and is another important channel which will affect the transition of advantages on factor supply in one country. It should be emphasized that the above-mentioned channels will have different effects on countries at different stages of economic development. Whether the roles can be brought into play or not depends on given restraints. The input output of factors themselves cannot form a clear function, but will interact together and act on economic growth hand in hand through numerous feedback chain.Chinese economy is now undergoing transformation from elementary age to middle age of industrialization. Service trade and investment in current period have both advantages and disadvantages.Based on these judgments, we propose that China should pursue a policy favoring protectionism on management of service trade and adopt relevant countermeasures as follows. Scientific development view should be formed with an eye to harmonizing development of three industries so as to lay a solid industries foundation for service trade; The strategic programming should be stipulated and the market of service trade should be opened gradually; The rule of international transfer of service trade should be mastered and environment of utilizing foreign investment on service industry should be improved.As the characteristics of the world's service-oriented economy have gradually emerged, service trade originating from the upgrading of industrial structure has developed rapidly, and the scale of service trade is rapidly expanding. From the statistical data, the total exports of world service trade rose rapidly from 365 billion U.S. dollars in 1980 to 377.779 billion U.S. dollars in 2008, an increase of 9.35 times. Compared with the trade of goods with a long history, service trade is a new form of trade. With the continuous increase in absolute size and relatively low levels, service trade has become a focus of attention in modern society.2 The impact of overall service trade on economic growthAccording to the WTO General Agreement on Trade in Services (GA TS), which was signed in 1994, trade in services includes Cross- border Supply, Consumption A broad, Commercial Presence, and naturalperson mobility. (Movement of Natural Persn) Four modes. The service trade of these four modes has completely different properties and characteristics. Therefore, it is difficult to establish a unified theoretical framework for service trade to affect economic growth. The corresponding literature is very rare. The only foreign documents are mainly Robinson et al. (2002), who simply regard service trade as a commodity. Trade, without taking into account differences in the four trade models, studied the economic growth effects of service trade liberalization using the Computable General Equilibrium (CGE) model.Using empirical methods to study the literature on the impact of overall service trade on economic growth is more, but such studies are mostly domestic scholars. Research shows that the average contribution of China's overall service trade to economic growth is 18.9%.3 Effect of Service Trade in Different Industries on Economic GrowthAt present, the literature on the impact of industry trade in service trade on economic growth is mostly concentrated in such service sectors as finance, telecommunications, and health care. These studies have basically reached a relatively unanimous conclusion that the opening of the service sector or the increase in productivity can significantly promote economic growth. . For example, studies by Beck et al. (1998), M urinde & Ryan (2003), and Eschenbach (2004) suggest that the opening of the financial sector has, to a certain extent, broken the monopoly of domesticfinancial markets and prompted the orderly competition of financial markets. On the normal development track, productivity has improved, and it has finally led to economic growth in the country. Kim (2000) studied the relationship between the development of service trade in the distribution sector and the growth of total factor productivity (TFP) using Korea's input-output data. The results show that the liberalization of service trade not only significantly promoted its own TFP. The promotion also promoted the improvement of total factor productivity in the related manufacturing sector. The total factor productivity growth brought about by service trade almost covered the entire economic sector.4 Effect of Service Trade on Economic Growth by Different Trading ModesThere are few literatures on specific transaction models and theoretical studies on the impact of trade in services on economic growth. Carr et al. (2001) & M arkusen et al. (2005) theoretically examined the commercial existence model by means of the CGE model. The impact of the trade in services on economic growth shows that the opening up of trade in services is an important source of the increase in economic welfare of a country. From the perspective of economic welfare, the opening up of trade in services is a general trend. Subsequently, the use of CGE models to theoretically examine the impact of service trade on economic growth began to prevail. For example, Rutherford et al. (2005)used the CGE model to evaluate Russia's WTO accession effects, and Ko nan &Maskus (2006) used CGE models. The potential effects of Tunisia's elimination of barriers to trade in services were studied. Their conclusions indicate that the increase in the level of economic welfare in one country can benefit from the opening up of the service market, while the elimination of FDI market access barriers in the service sector is a pattern of four trades. The most important liberalization measures are the main sources of increased welfare in a country. There are a lot of literatures on the relationship between service trade and economic growth in specific models using empirical methods. In the four modes of trade in services, commercial presence is the most important one, and from the point of view of data availability, although statistical data is still not very accurate, commercial existence of service trade is based on service industry FDI as a carrier. To achieve this, researchers can use service industry FDI data to characterize the scale of service trade in this model, and this type of trade model has received more attention. Among them, Markusen (1989) believes that the existence of commercial trade in services has two positive and negative effects. The positive effect is that competition in the service sector has led to an increase in domestic demand for the sector’s production factors, which is conducive to output growth. The effect of market size and negative effects means that the intensified competition in the domestic market of service industries has led to the withdrawal ofdomestic service-oriented enterprises from the market. The study by Markusen (1989) shows that the effect of market size after the opening of the service market far exceeds the crowding-out effect. After offsetting the crowding-out effect, it can still promote the productivity improvement of the non-service sector and further lead to the structure of domestic trade in goods. The changes, those sectors that were previously low in productivity and dependent on imports, will evolve into high-productivity export sectors, which is quite similar to the latest research findings on the interactive development of producer services and manufacturing. Hoekman (2006) and Hoekman (2006) used India as an example to examine the impact of the existence of commercial trade in services in the finance, telecommunications, and transportation sectors on the competitiveness of the goods export sector, and believe that these sectors have been liberalized. The level of soft facilities has been increased, which in turn has greatly reduced the operating costs of the downstream product manufacturing sector, which has increased the export competitiveness. With the inefficiency of the domestic service industry, the unfavorable pattern is reversed with the help of commercial presence of service trade. Feasible choice. Guerrieri et al. (2005) took the EU as the research object and analyzed the role of commercial trade in services for knowledge accumulation and economic growth. The study concluded that the openness of the service market or the relaxation of domesticservice regulations has positively promoted economic growth. It was found that the imported service items may be more able to promote economic growth than the domestic same service items due to high technological content.5 Possible Future Research DirectionsIt is not difficult to find from the above-mentioned documents that since the development of service trade started late, research on the growth of service trade began to rise gradually from the 1980s, and more than 20 years of research in this area is in the ascendant. With the further enhancement of the status of trade in services, the possible directions for future research will generally include the following aspects.From the point of view of research methodology, classification of service trade can be studied. As the theory of goods trade has gradually matured, the development practice of service trade still calls for the birth of the theory of service trade. Helpman and Markusen, international economists, expressed on different occasions that the difficulty in establishing the theoretical system of service trade lies in the fact that there are large differences in various types of service trades, and it is difficult for researchers to overcome the gap between them. Classifying service trade according to certain standards and exploring the impact of various types of service trade on economic growth is a possible direction for future research.From the perspective of the research subjects, it is possible to study China’s service trade and economic growth. China’s GDP has already ranked second in the world. However, the service industry’s added value accounted for only 40% of GDP, which is obviously not commensurate with the status of an economic power. In addition, the trade in services is still relatively small compared to the trade in goods. Under such a realistic background, what is the relationship between China's service trade and economic growth? How will service trade contribute to China's economic growth? What impact will service outsourcing have on China's economy? With China in In the next decade, how will China make service trade an engine of economic growth? From the academic point of view, economists from all countries are paying attention to China’s economic development, and China’s service trade will also be improved. It will become a research hotspot.From the perspective of research topics, it is possible to study the impact of service outsourcing on economic growth. In 2008, the scale of global service outsourcing market has reached 1.5 trillion US dollars. According to the UNCTAD (UNCT AD) speculation, the global service outsourcing market will increase by 30%-40% in the next 5-10 years.The surging service industry outsourcing is a new form of service trade. How does service outsourcing drive economic growth through employment, industrial structure upgrading, and technology spillovers?What are the differences in the impact of contracting and receiving services on economic growth in the service industry? Research on these issues will start with the development of service outsourcing to important theoretical guidance.中文译文国际服务贸易与经济增长理论与实证研究Chakraborty Kavin1 引言国际贸易与经济增长始终是国际经济学最生动的论题之一。

外文文献原稿和译文原稿DATABASEA database may be defined as a collection interrelated data store together with as little redundancy as possible to serve one or more applications in an optimal fashion .the data are stored so that they are independent of programs which use the data .A common and controlled approach is used in adding new data and in modifying and retrieving existing data within the data base .One system is said to contain a collection of database if they are entirely separate in structure .A database may be designed for batch processing , real-time processing ,or in-line processing .A data base system involves application program, DBMS, and database.THE INTRODUCTION TO DATABASE MANAGEMENT SYSTEMSThe term database is often to describe a collection of related files that is organized into an integrated structure that provides different people varied access to the same data. In many cases this resource is located in different files in different departments throughout the organization, often known only to the individuals who work with their specific portion of the total information. In these cases, the potential value of the information goes unrealized because a person in other departments who may need it does not know it or it cannot be accessed efficiently. In an attempt to organize their information resources and provide for timely and efficient access, many companies have implemented databases.A database is a collection of related data. By data, we mean known facts that can be recorded and that have implicit meaning. For example, the names, telephone numbers, and addresses of all the people you know. You may have recorded this data in an indexed address book, or you may have stored it on a diskette using a personalcomputer and software such as DBASE Ⅲor Lotus 1-2-3. This is a collection of related data with an implicit meaning and hence is a database.The above definition of database is quite general. For example, we may consider the collection of words that made up this page of text to be usually more restricted. A database has the following implicit properties:● A database is a logically coherent collection of data with some inherent meaning. A random assortment of data cannot be referred to as a database.● A database is designed, built, and populated with data for a specific purpose. It has an intended group of user and some preconceived applications in which these users are interested.● A database represents some aspect of the real world, sometimes called the miniworld. Changes to the miniworld are reflected in the database.In other words, a database has some source from which data are derived, some degree of interaction with events in the real world, and an audience that is actively interested in the contents of the database.A database management system (DBMS) is composed of three major parts: (1) a storage subsystem that stores and retrieves data in files; (2)a modeling and manipulation subsystem that provides the means with which to organize the data and to add, delete, maintain, and update the data; and (3) an interface between the DBMS and its users. Several major trends are emerging that enhance the value and usefulness of database management systems.●Managers who require more up-to-date information to make effective decisions.●Customers who demand increasingly sophisticated information services and more current information about the status of their orders, invoices, and accounts.●Users who find that they can develop custom applications with database systems in a fraction of the time it takes to use traditional programming languages.●Organizations that discover information has a strategic value; they utilize their database systems to gain an edge over their competitors.A DBMS can organize, process, and present selected data elements from the database. This capability enables decision makers to search, probe, and query database contents in order to extract answers to nonrecurring and unplanned questions that aren’t available in regular reports. These questions might initially be vague and/or p oorly defined, but people can “browse” through the database until they have the needed information. In short, the DBMS will “mange” the stored data items and assemble the needed items from the common database in response to the queries of those who aren’t programmers. In a file-oriented system, user needing special information may communicate their needs to a programmer, who, when time permits, will write one or more programs to extract the data and prepare the information. The availability of a DBMS, however, offers users a much faster alternative communications path.DATABASE QUERYIf the DBMS provides a way to interactively enter and update the database ,as well as interrogate it ,this capability allows for managing personal database. However, it does not automatically leave an audit trail of actions and does not provide the kinds of controls necessary in a multi-user organization .There controls are only available when a set of application programs is customized for each data entry and updating function.Software for personal computers that perform some of the DBMS functions has been very popular .Individuals for personal information storage and processing intended personal computers for us .Small enterprises, professionals like doctors, architects, engineers, lawyers and so on have also used these machines extensively. By the nature of intended usage ,database system on there machines are except from several of the requirements of full-fledged database systems. Since data sharing is not intended, concurrent operations even less so ,the software can be less complex .Security and integrity maintenance are de-emphasized or absent .as data volumes will be small, performance efficiency is also less important .In fact, the only aspect of a database system that is important is data independence. Data independence ,as stated earlier ,means that application programs and user queries need not recognize physical organization of data on secondary storage. The importance of this aspect , particularly for the personal computer user ,is that this greatly simplifies database usage . The user can store ,access and manipulate data at ahigh level (close to the application)and be totally shielded from the low level (close to the machine )details of data organization.DBMS STRUCTURING TECHNIQUESSpatial data management has been an active area of research in the database field for two decades ,with much of the research being focused on developing data structures for storing and indexing spatial data .however, no commercial database system provides facilities for directly de fining and storing spatial data ,and formulating queries based on research conditions on spatial data.There are two components to data management: history data management and version management .Both have been the subjects of research for over a decade. The troublesome aspect of temporal data management is that the boundary between applications and database systems has not been clearly drawn. Specifically, it is not clear how much of the typical semantics and facilities of temporal data management can and should be directly incorporated in a database system, and how much should be left to applications and users. In this section, we will provide a list of short-term research issues that should be examined to shed light on this fundamental question.The focus of research into history data management has been on defining the semantics of time and time interval, and issues related to understanding the semantics of queries and updates against history data stored in an attribute of a record. Typically, in the context of relational databases ,a temporal attribute is defined to hold a sequence of history data for the attribute. A history data consists of a data item and a time interval for which the data item is valid. A query may then be issued to retrieve history data for a specified time interval for the temporal attribute. The mechanism for supporting temporal attributes is to that for supporting set-valued attributes in a database system, such as UniSQL.In the absence of a support for temporal attributes, application developers who need to model and history data have simply simulated temporal attributes by creating attribute for the time interval ,along with the “temporal” attribute. This of course may result in duplication of records in a table, and more complicated search predicates in queries. The one necessary topic of research in history data management is to quantitatively establish the performance (and even productivity) differences betweenusing a database system that directly supports attributes and using a conventional database system that does not support either the set-valued attributes or temporal attributes.Data security, integrity, and independenceData security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database of the database, called subschemas. For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data.Data integrity refers to the accuracy, correctness, or validity of the data in the database. In a database system, data integrity means safeguarding the data against invalid alteration or destruction. In large on-line database system, data integrity becomes a more severe problem and two additional complications arise. The first has to do with many users accessing the database concurrently. For example, if thousands of travel agents book the same seat on the same flight, the first agent’s booking will be lost. In such cases the technique of locking the record or field provides the means for preventing one user from accessing a record while another user is updating the same record.The second complication relates to hardware, software or human error during the course of processing and involves database transaction which is a group of database modifications treated as a single unit. For example, an agent booking an airline reservation involves several database updates (i.e., adding the passenger’s name and address and updating the seats-available field), which comprise a single transaction. The database transaction is not considered to be completed until all updates have been completed; otherwise, none of the updates will be allowed to take place.An important point about database systems is that the database should exist independently of any of the specific applications. Traditional data processing applications are data dependent.When a DMBS is used, the detailed knowledge of the physical organization of the data does not have to be built into every application program. The application program asks the DBMS for data by field name, for example, a coded representationof “give me customer name and balance due” would be sent to the DBMS. Without a DBMS the programmer must reserve space for the full structure of the record in the program. Any change in data structure requires changes in all the applications programs.Data Base Management System (DBMS)The system software package that handles the difficult tasks associated with creating ,accessing and maintaining data base records is called a data base management system (DBMS). A DBMS will usually be handing multiple data calls concurrently.It must organize its system buffers so that different data operations can be in process together .It provides a data definition language to specify the conceptual schema and most likely ,some of the details regarding the implementation of the conceptual schema by the physical schema.The data definition language is a high-level language, enabling one to describe the conceptual schema in terms of a “data model “.At the present time ,there are four underling structures for database management systems. They are :List structures.Relational structures.Hierarchical (tree) structures.Network structures.Management Information System(MIS)An MIS can be defined as a network of computer-based data processing procedures developed in an organization and integrated as necessary with manual and other procedures for the purpose of providing timely and effective information to support decision making and other necessary management functions.One of the most difficult tasks of the MIS designer is to develop the information flow needed to support decision making .Generally speaking ,much of the information needed by managers who occupy different levels and who have different levels and have different responsibilities is obtained from a collection of exiting information system (or subsystems)Structure Query Language (SQL)SQL is a data base processing language endorsed by the American NationalStandards Institute. It is rapidly becoming the standard query language for accessing data on relational databases .With its simple ,powerful syntax ,SQL represents a great progress in database access for all levels of management and computing professionals.SQL falls into two forms : interactive SQL and embedded SQL. Embedded SQL usage is near to traditional programming in third generation languages .It is the interactive use of SQL that makes it most applicable for the rapid answering of ad hoc queries .With an interactive SQL query you just type in a few lines of SQL and you get the database response immediately on the screen.译文数据库数据库可以被定义为一个相互联系的数据库存储的集合。