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说明转8AG、转8G型转向架的结构特点。

答案

参考答案:

转8AG型转向架在转8A型转向架基础上,加装交叉支撑装置,加装心盘磨耗盘,采用双作用弹性旁承,采用两级刚度弹簧,采用奥-贝球铁衬套,为适应两级刚度弹簧将摇枕弹簧定位圆脐加高;为适应交叉支撑装置,采用了新结构的下拉杆;其他主要零部件(摇枕、侧架、制动梁、轮对等)与转8A型转向架相同。

转8G型转向架在转8A型转向架侧架基础上,将侧架外弯钩断面变成箱形结构;采用嵌入式滑槽磨耗板;增加左、右支撑座各1个、保持环4个;其他零件(磨耗板、斜楔挡、铆钉等)与转8A型转向架相同。

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Internet is a vast network of computers that connects many of the world’s businesses, institutions, and individuals. (46) The Internet, which means interconnected network of networks, links tens of thousands of smaller computer networks. These networks transmit huge amounts of information in the form of words, images, and sounds.

The Internet has information on every topic.(47)Network users can search through sources ranging from vast databases to small electronic" bulletin boards", where users form discussion groups around common interests. Much of the Internet’s traffic consists of messages sent from one computer user to another. These messages are called electronic mail or e-mail. Internet users have electronic addresses that allow them to send and receive e-mail. Other uses of the network include obtaining news, joining electronic debates, and playing electronic games.(48)One feature of the Internet, known as the World Wide Web, provides graphics, audio, and video to enhance the information in its documents. These documents cover a vast number of topics.

People usually access the Internet with a device called a modem. Modems connect computers to the network through telephone lines. Much of the Internet operates through worldwide telephone networks of fiber-optic cables(49) These cables contain hair-thin strands of glass that carry data as pulses of light. They can transmit thousands of times more data than local phone lines, most of which consist of copper wires.

In the future, the internet will probably grow more sophisticated as computer technology becomes more powerful. (50)Many experts believe the Internet may become part of a larger network called the information superhighway. This network, still under development, would link computers with telephone companies, cable television stations, and other communication systems. People could bank, shop, watch TV, and perform many other activities through the network.

(48)One feature of the Internet, known as the World Wide Web, provides graphics, audio, and video to enhance the information in its documents.