问题 问答题 简答题

简述热模锻压力机的工作特性。

答案

参考答案:

1)工作时,滑块的压力基本属于静压,工作时无震动和噪音。

2)滑块行程一定,每一模锻工步只需一次行程完成。

3)滑块具有附加导向的象鼻形结构,从而增加了导向长度,提高了导向精度和承受偏载能力。

4)具有上、下顶杆装置,便于锻后工件脱模。

填空题


International free trade occurs when there are no barriers to trade. Countries can get a lot of benefits from free trade. (31) , all countries choose to adopt protection policies to some extent In this essay, I will give (32) of the arguments in favour of world free trade, describe the methods for the trade protection policies (33) countries erect to protect domestic industries and give the arguments which can be put (34) to justify protectionist policies.
Tariffs are taxes on (35) products. Sometimes, tariffs are known (36) imports duties and customs duties. They can be used (37) raise revenue. But, they are usually used to (38) imports and also to help domestic producers. The effect of imposing (39) tariff is to raise price for domestic consumers, and some consumers will switch consumption (40) imported goods to domestically produced substitutes. (41) are two types of tariffs. One is percentage taxes, it is based on
percentage of value of goods. (42) one is specific (fixed sum taxes), it is based on a fixed tax (43) unit or weight. Quota is a limit on the supply of goods or services. It can be imposed on exports. The domestic market share will increase because of (44) a limit on the quantity of imported goods. However, the price of protected goods will also rise because a quota is to reduce supply. Voluntary export restraint or restriction (45) similar to a quota, but this time the limit on imports arises from a voluntary agreement (46) the exporting and importing countries. For example, the UK had an agreement with Japanese car (47) that they should not take (48) than 10 percent of the UK car market. Exchange control means that a government control on foreign currency controls importers access to foreign currency. This is a (49) which was used by a number of European countries, (50) the UK, in the 1960s and 1970s and is still found in some developing countries.

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