已知函数f(x)=lnx+a-xx,其中a为常数,且a>0.(1)若曲线y=f(

题型:解答题

问题:

已知函数f(x)=lnx+
a-x
x
,其中a为常数,且a>0.
(1)若曲线y=f(x)在点(1,f(1))处的切线与直线y=
1
2
x+1
垂直,求a的值;
(2)若函数f(x)在区间[1,2]上的最小值为
1
2
,求a的值.
考点:函数的极值与导数的关系函数的最值与导数的关系
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职工因工作遭受事故伤害需要暂停工作接受工伤医疗,其停工留薪期一般不超过12个月,伤情严重或者情况特殊,经社区的市场劳动能力鉴定委员会确认,可以适当延长,但延长不得超过()个月。

A.3

B.6

C.9

D.12

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cAMP能变构激活

A.磷脂酶A

B.蛋白激酶A

C.蛋白激酶C

D.蛋白激酶G

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The news that China bans time-travel TV dramas and movies got a lot of attention on the internet. Yet, time travel in China is a bit different from time travel in common sense.It is anything but science fiction and always goes backwards in time.There is minimum imagination involved--no ever-ending circles that mess up present and future, no advanced technology, no new social orders or new human forms from the twenty--whatever century, everything is a known historical fact when you travel through in China.

It is not even called time travel; rather the Chinese people refer it as time crossover.Time crossover has been an extremely popular theme for online novels for years(in fact , it is an indispensible part of China’s online culture), and didn’t get picked up by TV and the big screen until recent two years.Most of time-travel dramas and movies are adapted from popular online novels and like in other cases adaptations are never better than the original books.

The main plot of time-travel novels or TV dramas can be very well summarized in one sentence: from nobody to somebody.Time travel in China is more about escaping from the reality than about realizing wild dreams.

In China , there is no need of time machine either.People travel backwards in time via the possession of antiques presence at historical places of interest encounter of life-threatening accidents or simple a look into the mirror.Some time-travel novels even start with “I wanted to go back to history so much that one morning when I opened my eyes I was back.” Technology is not relevant at all.

Though China is not short of histories to go back to, people have their own preferences and it is pretty much a gender (性别)thing.If the main character is male then he usually goes back to special times in history when he is able to help build up or tear up a dynasty.A typical example is A Step Into the Past(寻秦记), the first time-travel TV drama in China, which tells the story of how a SWAT member helps to unite China and build up Qin Dynasty .

On the other hand , female characters primarily go back to Qing Dynasty partly because Qing Dynasty has the most number of princes to fall in love with.Yongzheng Emperor is the favorite.As can be seen in Startling by Each Step(步步惊心), a Qing time crossover classic, a girl goes back to Qing Dynasty and falls in love with Yongzheng Emperor and his brothers.

小题1:As for time travel in China, which of the following ideas does the writer agree to ?

A.it is complicated and can be classified into science fiction.

B.it is often based on the familiar story in history.

C.it sometimes messes up the times and social orders.

D.it always occurs in any times but the time before.小题2:The writing purpose of this passage is to           .

A.analyze why the time -travel TV dramas are banned in China

B.introduce the characteristics of the time-travel TV dramas in China

C.show the difference between time travel in China and in other cultures

D.advise people to watch the time-travel TV dramas in China小题3:It can be inferred from the passage that          .

A.China now has banned any forms of productions about time travel

B.adapted from online novels, time-travel TV and movie productions enjoy more praise

C.the main character always follows a set pattern in the time-travel TV dramas in China

D.all the time-travel productions are about heroes and their success小题4:The news mentioned in the very beginning is intended to         .

A.prove author’s view

B.introduce the topic

C.give an example

D.work as a topic sentence

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文学革命初期新诗作者有()、()、()、()、()。

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黄宗羲在《明夷待访录》中说:“用一人焉则疑其自私,而又用一人以制其私;行一事焉则虑其可欺,而又设一事以防其欺。”能体现这一特点的中国古代政治制度有()

①三省六部制

②明朝的内阁

③清朝的军机处

④宋朝在中央设置中书门下,在地方设置通判

A.①④

B.①③

C.②④

D.②③

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