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什么是引力红移？引起引力红移的原因是什么？什么星具有引力红移的特性？

答案

参考答案：

引力红移：是爱因斯坦广义相对论的一个推论。按照广义相对论，在远离引力场的地方观测引力场中的辐射源发射出来的光时，光谱线向红端移动，即同一条原子谱线比没有引力场的情况下，波长变长。波长红移的大小与辐射源和观测者两处的引力势差成正比。

原因：由于白矮星半径很小，密度很大，引力场很强，光子离开表面克服引力要损失相当的能量，一个光子的能量为hν（h为普朗克常量）与它的频率成正比，能量减少频率就降低，所以波长变长。此红移不是光源移动引起的多普勒位移，而是引力场引起的红移，所以叫引力红移。例如，由光谱观测，测出天狼B星的引力红移是89km/s，波江座40的引力红移是23.9km/s白矮星有一个奇异的特性，就是引力红移现象

单项选择题 A1型题

只能由司法机关代表国家依照法定程序予以追究的是（）。

A.民事责任

B.行政责任

C.刑事责任

D.行政行为

E.纪律处分
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问答题

Part 1


·Read the following passages, eight sentences have been removed from the article.
·Choose.from the sentences A-H the one which fits each gap.
·For each gap (1-8) mark one letter (A-H) on the Answer Sheet.
·Do not mark any letter twice.
Today’s career assumptions are you can get a lot of development, challenge and job satisfaction and not necessarily be in a management role.
A new malady is running rampantly in corporate America: management phobia. (1)
" I hated all the meetings," says a 10-year award-winning manager, "and I found the more you did for people who worked for you, the more they expected." (2)
With technology changing in a wink, you can never slack off these days if you’re on the technical side. (3)
In addition, the Dilbert factor is at work. With Scott Adams’s popular cartoon character— as well as many television sitcoms — routinely portraying managers as morons or enemies, they just don’t get much respect anymore.
Supervising others was always a tough task, but in the past that stress was offset by hopes for career mobility and financial rewards. (4)
But in today’s global, more competitive arena, a manager sits on an insecure perch. (5) There are far fewer rungs on the corporate ladder for managers to climb. In addition, managerial jobs demand more hours and headaches than ever before but offer slim, if any, financial paybacks and perks.
Furthermore, managers now must supervise many people who are spread over different locations, even over different continents. (6)
In an age of entrepreneurship, when the most praised people in business are those launching something new, management seems like an invisible, thankless role. (7)
Management layoffs have done much to erode interest in managerial jobs, of course. (8)
A. Many people don’t want to be a manager — and many people who are managers are, frankly, itching to jump off the management track — or have already.
B. It’s a rare person who can manage to keep up on the technical side and handle a management job, too.
C. Restructuring have eliminated layer after layer of management as companies came to view their organizations as collections of competencies rather than hierarchies.
D. They must manage across functions with, say, design, finance, marketing and technical people reporting to them.
E. I was a counselor, motivator, financial adviser and psychologist.
F. Employers are looking for people who can do things, not for people who make other people do things.
G. American Management Association surveys say three middle managers are laid off for every one being hired.
H. Along with a sizable pay raise, people chosen as managers would begin a nearly automatic climb up the career ladder to lucrative executive perks: stock options, company cars, club memberships, plus the key to the executive washroom.
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