端粒(telomere)

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问题:

端粒(telomere)

考点:普通考研07理学分子生物学
题型:问答题

In the span of 18 months, Isaac Newton invented calculus, constructed a theory of optics, explained how gravity works and discovered his laws of motion. As a result, 1665 and the early months of 1666 are termed his annus mirabilis. (46)It was a sustained sprint of intellectual achievement that no one thought could ever be equaled. But in a span of a few years just before 1900, it all began to unravel. One phenomenon after another was discovered which could not be explained by the laws of classical physics. (47) The theories of Newton, and of James Clerk Maxwell who followed him in the mid-19th century by crafting a more comprehensive account of electromagnetism, were in trouble.
Then, in 1905, a young patent clerk named Albert Einstein found the way forward. In five remarkable papers, he showed that atoms are real (it was still controversial at the time), presented his special theory of relativity, and put quantum theory on its feet. It was a different achievement from Newton’s year, but Einstein’s annus mirabilis was no less remarkable. He did not, like Newton, have to invent entirely new forms of mathematics. However, he had to revise notions of space and time fundamentally. (48) And unlike Newton, who did not publish his results for nearly 20 years, so obsessed was he with secrecy and working out the details, Einstein released his papers one after another, as a fusillade of ideas.
For Einstein, it was just a beginning-he would go on to create the general theory of relativity and to pioneer quantum mechanics. While Newton came up with one system for explaining the world, Einstein thus came up with two. Unfortunately, his discoveries- relativity and quantum theory-contradict one another. Both cannot be true everywhere, although both are remarkably accurate in their respective domains of the very large and the very small. Einstein would spend the last years of his life attempting to reconcile the two theories, and failing. (49) But then, no one else has succeeded in fixing the problems either, and Einstein was perhaps the one who saw them most clearly.
When Einstein was awarded a Nobel prize, in 1921, it was for the first of his papers of 1905, which proved the existence of photons-particles of light. (50) Up until that paper, completed on March 17th and published in Annalen der Physik (as were the other 1905 papers), light had been supposed to be a wave, since this explains the interference patterns created when it passes through a grating. Einstein, however, began from a different premise, by considering the so-called "black-body experiment".

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对防火间距实地进行测量时,沿建筑周围选择相对较近处测量间距,测量值的允许负偏差不得大于规定值的()%。

A.2

B.3

C.5

D.10

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导致环境质量下降,生态平衡失调的最主要原因是(  )

A.人口过度增长

B.水旱自然灾害

C.火山经常爆发

D.地震频繁发生

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北部湾经济区要积极推进()经济合作,打造次区域合作的新亮点,成为中国—东盟开放合作的战略高地。

A、泛北部湾

B、泛珠三角

C、中越边境

D、大湄公河次区域

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下列人体不同种类的体液之间,电解质浓度差别最大的一组是()

A.血浆与组织液的HCO

B.组织液与细胞内液的蛋白质

C.血浆与组织液的Cl-

D.组织液与淋巴的Na+

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