在变形区内靠近轧辊的出口处,金属的纵向流动速度大于轧辊在该处的线速度,这种现象称为(

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问题:

在变形区内靠近轧辊的出口处,金属的纵向流动速度大于轧辊在该处的线速度,这种现象称为()。

考点:轧钢工考试轧钢成品工(中级)轧钢成品工(中级)题库
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世界上阿拉伯人的主要聚居地区之一是[ ]

A.西亚

B.东南亚

C.南亚

D.欧洲西部

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晶体对称的特点?

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When TV news programs report wars or disasters, the editors rarely use the most horrifying pictures of dead or wounded victims because they don’t want to upset their viewers. Even so, viewers are usually warned in advance that they may find some of these scenes disturbing, so they can look away if they choose. But the men and women whose job is to record those scenes-the TV cameramen-have no such choice. It is their duty to witness the horrors of the world and record them, no matter how terrible and unpleasant they may be. Consequently, it is one of the most dangerous, exposed and emotionally taxing jobs the world has to offer.

Today, the demand for their work is rising. The explosion of satellite broadcasting and 24-hour news in recent years has created an almost insatiable (贪得无厌的) demand for TV information. But major broadcasters and the TV news agencies—such as Reuters and WTN-have never had enough staff to meet the worldwide demand for up-to-date pictures, so increasingly they turn to “freelance” TV cameramen.

These freelance cameramen are independent operators tied to no particular organization. They will work for any company which hires them, be it for just a few hours or for several weeks in a war zone. But if the freelance cameraman is injured in the course of the job, the TV company is not responsible for him. The freelancer must survive on his own.

TV will always need hard, vivid moving pictures which are fresh, but these companies feel uncomfortable with large numbers of employees on their books, explains Nick Growing, once foreign editor for Britain Channel 4 News and now a BBC news presenter.

By hiring freelancers, they can buy in the skills they need only when they need them. It also enables them to contract out the risk, he says.

小题1:TV news agencies turn to freelance cameramen in order to           .

A.save expense and avoid risks

B.get free and useful pictures

C.get first-hand information and pictures

D.satisfy the greed of the freelance cameramen小题2:We can infer from the passage that the freelance cameramen             .

A.have to take a lot of risks in the course of work

B.are tied to many TV news agencies

C.have better skills than other cameramen

D.need to contract out risks of work for TV companies小题3:According to this passage, some major broadcasters and TV news agencies            .

A. have employed enough cameramen

B. are not willing to employ many cameramen

C. are very mean to freelancers

C. are responsible for the freelancer if he is injured

小题4:The author of this passage shows his           the freelance cameramen.

A.sympathy to

B.respect for

C.anger to

D.admiration to

题型:填空题

 “低碳循环”引起各国的高度重视,而如何降低大气中CO2的含量及有效地开发利用CO2,引起了全世界的普遍重视。所以“低碳经济”正成为科学家研究的主要课题

(1)用电弧法合成的储氢纳米碳管常伴有大量的碳纳米颗粒(杂质),这种颗粒可用如下氧化法提纯,请完成该反应的化学方程式:

___ C+ ___ KMnO4+ ____ H2SO4→____CO2↑+ ____MnSO4 + ____K2SO4+ ____H2O  

(2)将不同量的CO(g)和H2O(g)分别通入到体积为2L的恒容密闭容器中,进行反应

CO(g)+H2O(g)CO2(g)+H2(g),得到如下三组数据

①实验1条件下平衡常数K=________(取小数二位,下同)。

②实验3中,若平衡时,CO的转化率大于水蒸气,则a/b 的值_______(填具体值或取值范围)。

③实验4,若900℃时,在此容器中加入10molCO,5molH2O,2molCO2,5molH2,则此时

V______V(填“<、>、=”)。

(3)已知在常温常压下:

① 2CH3OH(l) + 3O2(g) = 2CO2(g) + 4H2O(g)   ΔH = -1275.6 kJ/mol

② 2CO(g)+ O2(g) = 2CO2(g)   ΔH = -566.0 kJ/mol

③ H2O(g) = H2O(l)   ΔH = -44.0 kJ/mol

写出甲醇不完全燃烧生成一氧化碳和液态水的热化学方程式:___________________

(4)最近有科学家提出构想:把空气吹入碳酸钾溶液,然后再把CO2从溶液中提取出来,经化学反应后使之变为可再生燃料甲醇。该构想技术流程如下:

向分解池中通入高温水蒸气的作用是_______________________________     

(5)CO2在自然界循环时可与CaCO3反应,CaCO3是一种难溶物质,其Ksp=2.8×10-9

CaCl2溶液与Na2CO3溶液混合可形成CaCO3沉淀,现将等体积的CaCl2溶液与Na2CO3溶液混合,若Na2CO3溶液的浓度为2×10-4mo1/L ,则生成沉淀所需CaCl2溶液的最小浓度为________________ 。

题型:填空题

买来的域名会继承之前从百度得到的评分属性吗()

A、不会

B、会

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