英文文献及翻译中国高速铁路ChinaHighSpeedRailway
China High-Speed Railway
李汉娜
rally As the economic grow, intercity travel demand has incread dramatically in the Greater China Area. Traditional railways can hardly satisfy the pasnger and freight travel demand, high speed rail is hence propod and constructed after 1990s. This study aims to integrate current development of both rail-bad and Maglev high speed trains in this area. From 1997, Taiwan kicked-off its high speed rail construction by importing the technology of Japane Shinkann. The Taiwan High Speed Rail is a 15-billion US dollars project. To save the cost of construction and management, the BOT model was applied. Though not totally satisfied, this project is still successful and ready to operate in the 4th quarter of 2007. China is preparing its high speed rail rvices by upgrading current networks. The capacity and operating speed are all incread after 5-times system upgrade. The 6th upgrade will be initiated in 2006. By then, trains will run at a speed of 200km/h in a total distance of 1,400km in 7 different routes. From the white paper published by the Ministry of
vlinkRailway in China, there will be totally 8 rail-bad High Speed Train rvices. Four of them are North-South bound, and four of them are East-West bound. 5 of the 8 High Speed Rails are now under construction, the first line will be finished in 2009, and the 2nd one will be in 2010. By 2020, there will be totally 12,000 kilometers high speed rail rvices in China. The 250 billion US dollars construction cost still leaves some uncertainties for all the projects. Finally, the future of the Maglev system in China is not so bright as rail-bad. Shanghai airport line could be the first, also the last Maglev project in China if the approved Shanghai-Hangzhou line cannot rai enough 4.4 billion dollars to build it.
Steel rail composition
苏州英语培训 Steel rail is compod of iron, carbon, mangane, and silicon, and contains impurities such as phosphorous, sulphur, gas, and slag. The proportions of the substances may be altered to achieve different properties, such as incread resistance to wear on curves.
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aquarion The standard configuration for North American rail rembles an upside down T. The three parts of T-rail are called the ba, web, and head. The flat ba enabled such rail to be spiked directly to wooden crossties; later, rail was placed on the now-standard steel tie plate. While the proportions and preci shape of rail are subject to constant analysis and refinement, the basic T-ction has been standard since the mid-19th century.
松鼠的英文
Weight
The most common way of describing rail is in terms of its weight per linear yard (the historic British unit of length), which is a function of its cross ction. In the late 19th century,
rail was produced in a range of ctions weighing between 40 and 80 lbs. per yard. Weights incread over time, so that rail rolled today weighs between 112 and 145 lbs. (The Pennsylvania Railroad“s 155-lb. ction, ud for a time after World War II, was the heaviest ud in the U.S.)
Jointed rail gments
The length of standard rails has historically been related to the length of the cars ud to transport them. From an early range of 15-20 feet, rail length incread with car size until a standard of 39 feet (easily accommodated by the once-common 40-foot car) was reached. Even with the advent of today"s longer cars, 39 feet has remained the standard for rail owing to limitations in steel mills and ea of handling.
The joints in rail — its weakest points — can make for a rough ride, and are expensive to maintain. Individual rails are joined with steel pieces called joint (or angle) bars, which are held in place by four or six bolts. Today, the six-bolt type, once rerved for heavy-duty applications, is standard. The bolts in a joint bar are faced alternately outward and inward to guard against the remote possibility that a derailed car"s wheel would shear them all off, causing the rails to part. Transition between rails of two different weights is achieved with special angle bars. In territory where the rails rve as conductors for signal systems, bond wires must be ud at the joints to maintain the circuit.
Welded rail
有道翻译器下载 The troublesome nature of rail joints prompted the most easily recognized advance in rail technology: the adoption of continuous welded rail (CWR).
From its early u on a handful of roads in the 1940"s, welded rail has come to be preferred for almost all applications. It is produced by welding standard 39-foot (or newer 78-foot) gments together into quarter-mile lengths at dedicated plants.美国大选辩论
大家的日语mp3下载 The rails are transported to where they"re needed in special trains, which are pulled slowly out from under the rail when it is to be unloaded. When in place, CWR is often field-welded into even greater lengths. Much jointed track survives becau of the long lifespan of even moderately ud rail, and becau the specialized equipment needed for CWR installation is not economical for short distances.
