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C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | thereby secure a definition and resolving power unthought of before. So Michelson designed the Echelon spectroscope, consisting of thick slabs of glass, each protruding a millimetre or so beyond the other—a staircase spectroscope—which is now a regular instrument in the examination of the minute structure of spectrum l... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 年轻的迈克尔逊在旧金山读完高中后被指派到海军学院学习一直到1873年毕业,两年后他成为桑普森上将手下的一名物理和化学教员,并在此一直工作到1879年。后来他又为华盛顿的航海天文历编制局工作了一年,此时已是海军少尉的迈克尔逊走出了国门,先后到柏林大学、海德堡大学、法兰西学院和巴黎理工学校深造。他在1883年回到美国,随即成为位于俄亥俄州克利夫兰的凯斯应用科学学院的物理教授;6年后,克拉克大学邀请他担任该校的教授,他在那里一直工作到1892年芝加哥大学成立。迈克尔逊教授在这个新建的大学中担任物理学教授和物理系系主任。1925年6月,由于该大学新发展规划的需要,他荣幸地被提名为首位对社会有杰出贡献的教授。
英文
“正是在克利夫兰工作... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | ’
英文
“‘如果在比较靠近我们的恒星中存在着一个与太阳大小差不多的恒星,那么它所张的角度将大约是1/100角秒;而观测这么小的角度需要10米的距离,望远镜物镜的直径完全可以达到这么长的距离,这个距离对于折光仪来说也毫无问题。然而,恒星所张角度大大高于1/100角秒的情况未必不可能出现;获得这些遥远发光体实际尺寸的有用信息是有可能的,而且值得人们投入时间、精力和耐心,而完成该项工作也需要这样的投入。’
英文
“在当时几乎无法希望,当然也没有理由期望,恒星的星盘能够大到足以感知和测量的地步,即便是采用孔径为30英尺的虚拟望远镜,不过一些最接近我们的恒星也许可以除外。然而,可能存在巨星的想法进入了我们的视野;爱丁顿提出了那个... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | continued to support the work after a skull had been found.) Black was a firm sinophile; born in 1884, he died at the early age of 59 in 1943.
中文
W
ITH characteristic promptitude, Prof. Davidson Black has now provided us with a full report upon the features of the Peking skull, giving a detailed description of its ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | endocranial cast. Fortunately, this was possible because the braincase was fractured, enabling the bones to be removed piecemeal. Moreover, the skull is that of a young adolescent, whose age, in Dr. Black's opinion, corresponds to that of a modern child between the time of eruption of the second permanent molar teeth a... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | more than ten years older than her companion. In the accompanying diagram (Fig. 1) Prof. Davidson Black's drawings of median longitudinal projections of the young skull (shaded) and of the adult (female) skull have been superimposed. The female skull is slightly thinner than that of the youth and is also larger, being ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | ”. In other words, the apparent primitiveness of the Java fossil is in part probably due to degenerative changes responsible for the uncouth shape of the skull, which presents so striking a contrast to the elegant and undistorted braincase of the Peking man. Apart from its massive supraorbital torus and reduced third m... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | , but points out that the range of unevenness in thickness of the Peking skull presents a marked contrast to the more uniform Piltdown fragments.
中文
Although Dr. Black himself has refrained from instituting detailed comparisons with the Piltdown skull, it is interesting to compare (Fig. 3) the transverse section he ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | approaches the horizontal. This state of affairs is lost in Homo sapiens
long before the age of puberty is attained. As Dr. Black remarks, the features of the tympanic region of Sinanthropus
are admirably suited to serve as a starting-point for phylogenetic speculation. “With this generalised type before us it is not... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | It is fortunate that the information concerning this unique material has been so fully and so promptly supplied to anthropologists in a monograph which is distinguished by admirable clearness and impartiality. Once more Prof. Davidson Black deserves our congratulations on a great achievement.
中文
(127
, 819-821; 193... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 左侧冠状缝的部分消失意味着后者是一位成年人,可能比前者大十多岁。在附图(图1)中,步达生教授将青年人的头骨(阴影部分)与成年女性的头骨的正中纵向投影图进行了重叠效果的展示。图1显示这位女性的头骨比青年人的稍微薄一些、大一些,比男性的头骨高一点、长一点,还有一些差异可能是性别差异的表现。
英文
图1. 北京头盖骨的正中纵向投影图。×1⁄2。
英文
鉴于某些作者主张应该将北京人头骨归到爪哇猿人属或者尼安德特人种中,步达生教授倾注了大量精力比较北京人头骨与爪哇猿人头骨和尼安德特种的不同代表的头骨投影图。通过具有统计意义的比较,他提出了确凿的证据,证实有必要建立一个新的属和种来接纳北京人头骨。
英文
尽管很明显,北京人与... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 英文
在中国发现北京人头骨的巨大价值不仅在于这里的材料比特里尼尔和皮尔当的遗存骸更丰富,它们的地质年代也是确定无疑的,而且,还在于尽管北京人不同于爪哇猿人属和曙人属,它比后两者都更一般化得多,但肯定与后两者都存在联系。尽管北京人是迄今发现的最原始类型的人类,其与在爪哇和在英国发现的化石人属在结构上的亲缘关系将所有已知的更新世人类都联系在了一起,也使我们的知识融会在了一起。
英文
很幸运,步达生教授将与北京人头骨这一独特材料有关的信息如此充分而且迅速地以一部条理清晰、论述公正的专著提供给了人类学家。步达生教授的伟大成就值得我们再一次祝贺。
英文
(刘皓芳 翻译;林圣龙 审稿)
*
步达生,“比较青年北京人头骨和成年北... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Prof. A. Windaus said that up to the present, investigations had had to be carried out on impure substances and chiefly by means of physical experiments. No stable equilibrium was formed between ergosterol and the products of irradiation. By further irradiation two crystalline substances could be obtained, neither of w... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Crude vitamin D is stable in oil, although the absorption spectrum and specific rotation rapidly change. The toxicity of the crude product varies with the potency, but it is still possible that the two properties may be due to different substances. The problem has not yet been solved. He had noticed that in vacuum tube... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Prof. B. C. P. Jansen said that Reerink and van Wijk had now obtained crystals of a melting point 140°. Their former product with a lower melting point had contained ether of crystallisation.
中文
Dr. R. B. Bourdillon said that the discovery of the method of obtaining crystals of vitamin D by means of maleic anhydride... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | observers.
中文
Dr. O. Rosenheim said he considered the work now reported was the most important since the original researches on vitamin D. He thought that Windaus’ and Bourdillon's crystals were identical, although it was possible that there might be an impurity present as in Reerink and van Wijk's preparation. Spec... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | test. The absorption spectrum is very similar to that attributed to vitamin A in cod liver oil.
中文
Moore considers that carotene is converted to vitamin A in the body of the rat. Prof. von Euler had tried to effect this conversion in vitro, but only with the serum of the hen had he found that carotene could be conve... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | , but only 100 grams of contaminating solid material. The vitamin B1
present accounted for only 1 percent of the adsorbed material. By fractional precipitation with silver nitrate and baryta it was possible to remove impurities at a strongly acid reaction and to precipitate two-thirds of the vitamin at p
H 4-7: above... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Prof. R. A. Peters said that he had hoped to be able to use the animal as a test object only and not concern himself with the physiological side of the problem, but he had found that it was only possible to reach a final conclusion on the chemistry when the physiology was also taken into account. He had been able to co... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 他表示:尽管学会以往对许多新发现都进行过交流,但在维生素方面的文章却是少之又少。能在自己的第一年任期内举行这样的讨论,他感到非常满意,尤其是因为这一主题正在引起越来越广泛的关注。学会为有许多国外的研究者参会而感到庆幸,因此这将是一次国际性的盛会。鉴于这一主题非常宽泛,他提议将其限定在维生素的化学特性方面,并建议按照维生素D、维生素A和维生素B复合物的顺序进行讨论。
英文
维生素D
温道斯教授说,迄今为止人们不得不对混合物进行研究,而且研究主要依靠的是物理实验。在麦角甾醇和其照射产物之间没有形成稳定的平衡,通过更长时间的照射可以得到两种结晶体,而这两种结晶体是不能相互转化的。因此可以得出结论:麦角甾醇在照射过程中生成了两个系列的... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 英文
罗森海姆博士认为现在报道的研究工作是自人们开展对维生素D的研究以来最为重要的工作。他认为温道斯和鲍迪伦的结晶体是相同的,尽管有可能会像雷林克和范维克的制备物一样存在一定的杂质。在光谱学方法的研究上并没有取得什么进展,但在生物学和有机化学方面却取得了成功,尤其是鲍迪伦的分级凝缩方法。他指出如果光照射麦角甾醇直到20%的物质发生了变化,然后将80%的无活性物质除去,那么残留物的活性才跟最初被照射的物质相同。将残留物进行蒸馏,可以得到占残留物20%的结晶,但其活性仅是天然产品的两倍。
英文
维生素A
冯欧勒教授说,人们很早就注意到脂溶性的促生长物质常常与红色或黄色相关联,但不能倒推。他与卡勒一起研究发现,在所有检测过的红色或... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 英文
彼得斯教授说,他曾希望能够只把动物作为测试对象而不考虑其生理学方面的问题,但是他发现只有在同时考虑生理学问题的时候,才有可能在化学方面得出最终的结论。他能够确定詹森教授的制备过程直到用氯化铂溶液进行沉淀的阶段。他从对酵母的研究中得到了这样的纯化方法:用醋酸铅和氧化钡除去无活性物质,接着用活性炭吸附维生素。在pH值为5~7下用磷钨酸进行分级沉淀就得到了维生素B1
,其活性为每次剂量0.012 mg,而詹森教授的结晶体活性为0.008 mg。在这两种制备方法中都发生了剧烈程度相同的波利反应。里德小姐曾表示詹森教授的结晶体中有25%~50%具有维生素B4
的活性。现在她已经能够在纯化阶段前期用活性炭分级吸附的方法从维生素B4
... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | attempt a survey of the present situation in respect to this question.
中文
The Astronomical Evidence
The astronomical argument for the annihilation of matter is based, not on the intensity of stellar radiation, but on its duration. No transformation of a less drastic nature than complete annihilation is found capable... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | These estimates of stellar ages are, of course, valid only if we assume that the changes in stellar motions and arrangements are produced solely by the gravitational pulls of other stars. Other causes are conceivable, and must indeed contribute something—pressure of radiation, bombardment by stray matter in space, or b... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | fission—and proceeding to orbits which are far from circular in shape, in which the components are at a substantial distance apart. It seems likely, although not certain, that this sequence is one of advancing age; when the parent star first breaks up to form a binary, the newly formed system starts at the first-mentio... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | exact, we could fix the age of the universe definitely at just more than 1,000 million years, which is substantially less even than the age of the earth as indicated by its radioactive rocks. No one would claim any great degree of exactness for either of these estimates, especially the second, yet the general situation... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Highly Penetrating Radiation
If any direct evidence of this process of annihilation is to be obtained, it seems most likely that it will be found in the highly penetrating radiation which McLennan, Rutherford, and others discovered in the earth's atmosphere at the beginning of the present century. The reason, as we sha... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | entangled in the earth's magnetic field, their high speed of motion would cause them to describe spiral paths coiled quite closely around the earth's lines of magnetic force, with the result that they would fall far more abundantly near the earth's magnetic poles than elsewhere. Epstein1
estimates that for a shower of... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | ionisation might be produced by a secondary corpuscular radiation.
中文
To examine this possibility, Bothe and Kohlhörster placed a block of gold between their two counters. This naturally caused a reduction in the number of coincidences, and from the amount of the reduction it was possible to calculate the penetratin... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | radiation to be of the nature of γ
radiation.
中文
The Mode of Production of the Radiation
If the primary radiation is of the nature of γ
radiation, as these arguments and experiments seem to show, its origin ought to be disclosed by its penetrating power. Such radiation consists of photons, which may be compared to... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | that there is a sort of softening effect continually in progress by which the absorption of a quantum of energy produces a recoil electron, which in turn produces radiation of energy comparable to, although somewhat lower than, the energy of the original quantum. After the radiation has travelled through a certain thic... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | The mass of the photon can be deduced from the observed absorption coefficient μ
of the radiation, by the use of a theoretical formula given by Klein and Nishina.6
This can be written in the form
where M
is the mass of the photon, m
of an electron, e
, c
have their usual meanings, and f
represents a fairly comp... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | -rays, which he believes to be of nuclear origin. In other words, he finds that some at least of the nuclear electrons in lead are not so closely coupled as to resist the onslaught of the hardest γ
-radiation. Still less, then, can they be so closely coupled as to resist the incidence of the far more massive photons o... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | The last column gives the absorption coefficients of the two most penetrating constituents of cosmic radiation, as analysed by Regener. Their agreement with the figures in the preceding column is probably well within errors of observation and analysis, and is rather too good to be attributed with much plausibility to m... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | radiation is found to have many times the ionising intensity of the primary. But whatever the origin of the softer constituents may be, the two hardest constituents, with their photons equal in mass to the atoms of hydrogen and helium respectively, appear to provide weighty evidence that matter can be, and is, annihila... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | The fact that the intensity of the radiation is very approximately independent of both solar and sidereal time seems to show that no appreciable part of the radiation comes from the sun or stars. Counting the sun as a star, we receive more than 100,000,000 times as much starlight at midday as at midnight, yet apart fro... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Thus, to an approximation, we may think of the hardest constituent of the cosmic radiation as indestructible, since the universe has not yet existed long enough for any appreciable amount of it to be absorbed. To a slightly less good approximation, the same is true of the softer constituents. This leads us to regard sp... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Indeed, the fact that the radiation does not vary in intensity with the position of the Milky Way may be thought to suggest that it is merely a relic of past eras in the history of the universe. It may be argued that if the radiation were still being generated, the huge mass of the Milky Way, comparatively close to our... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 中文
This is not surprising, since the cosmic radiation which pervades space is necessarily quite distinct from the similar radiation which astronomers regard as the source of stellar light and heat. The annihilation of matter in stellar interiors would produce radiation of exactly the same high frequency as the observe... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | The quantum theory replaces this continuous emission of energy by a succession of discontinuous emissions; at each moment there is a definite calculable chance that the orbit will shrink in size by a finite amount, and emit a photon in the process. The orbit of lowest energy is anomalous; when an electron is describing... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | to be of the order of a million million degrees. Now it is quite impossible that the cosmic radiation we receive on earth can have originated in regions where the temperature approaches this; indeed, we have seen that it can scarcely have been more than 100,000o or so. Thus this radiation can only have originated from ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | . This happens at the temperature of about a million million degrees already mentioned. When this temperature is first approached, the exponential term is increasing very rapidly in comparison with the temperature T
. But a dynamical investigation shows that when this happens, the star must be very unstable. In brief,... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | the problem of why no cosmic radiation is received directly from the Milky Way.
中文
(128
, 103-110; 1931)
References:
Proceedings: National Academy of Sciences
(Oct. 1930).
Nature
, 127
, 924 (June 20, 1931).
Millikan, Dec. 29, 1930, Lecture at Pasadena, reprinted in Nature
, 127
, 167 (Jan. 31, 1931).
Phys... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 单个恒星和双星都表现出与此数量级温度相对应的能量均分,显而易见,物理中介作用,比如辐射压力和原子压力等建立平衡的温度要低得多,只有104
度的量级,不可能对建立均分的过程有任何可观的贡献;它们不过是作为恒星运动的阻力罢了,平均而言往往是在减慢它们的速度。
英文
在第二类双星系统,即光谱双星中,两颗子星是如此之近,以至于从它们附近经过的恒星对它们两个的吸引效果几乎相同,因此就不能以不同的作用效果改变双星系统组成物的相对轨道。显然对于这种系统的内部运动,毫无疑问可以采取任意近似方式以达到其能量均分的状态。尽管如此,仍然可以描绘出双星系统结构所固有的演变过程,从仍相互接触的两组分所处的近似圆轨道开始,这很可能就是一个系统刚刚分裂形... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 如果一大群这样的粒子进入地球磁场,高速运动会使它们绕着非常接近地球磁力线的轨道做螺旋运动,结果在地球磁极附近落下的粒子要远远多于其他地方的粒子。爱泼斯坦[1]
估计对于一大批电子,若要具有宇宙辐射那样的穿透力,它们必须以大约穿过10亿伏特才能获得的能量运动,他还计算出以这个能量运动的入射电子将被完全限制在两磁极附近的相对较小的圆里。而实际上,观测到的辐射非常平均地落在地球表面的各个区域,并没有发现明显的差异。B.A.N.Z.南极探险队[2]
的成员发现,在南磁极周围250英里区域内的辐射强度,与他们之前在南澳大利亚测得的,以及其他人在美国、加拿大和北大西洋得到的结果相同。此辐射具有极硬γ
辐射的性质这一点似乎是无可置疑的[3]... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 不同的实验者并没有得到完全一致的结果,但是他们都一致认为在辐射区域的末端附近有一段很长的延伸范围,在这个范围内辐射强度呈简单的指数率衰减。这只能说明辐射中存在着一个特殊的成分,它比其他成分硬很多,以至于在经过一定厚度的介质后,所有较软的成分都已经被完全吸收,而这个成分的辐射仍然保持着相当的强度。雷格纳在对上述现象进行了仔细的研究之后发现,全部辐射中最硬的那个成分在被水吸收时的吸收系数为每米0.020。其他实验者得到的数值与此一致,偏差不超过10%。
英文
利用克莱因–仁科给出的理论公式,我们可以从观测到的辐射吸收系数μ
中推导出光子的质量[6]
。这个公式可以由下面的形式给出:
其中:M
为光子质量,m
为电子质量,... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 但是无论较软成分的来源是什么,这两个最硬成分中的光子所具有的质量分别与氢原子和氦原子的质量相同,这似乎为物质可以在遥远的空间中湮灭提供了有力的证据。如果我们假定这个过程发生在一个足够大的尺度内,那么这个假设就会使大量的天文学和宇宙学问题变得有条理并且易于理解,这是其他假设无法做到的。
英文
宇宙辐射产生的位置
对于这种高穿透性辐射起源于何处人们有不同的看法。其中的很多观点都被以下这个在我看来现在已被牢固确立的事实排除掉了,即无论是白天还是黑夜,宇宙辐射的强度在任何时候几乎都是一个常数[9]
,它的变化幅度至多为1/200量级。这个量似乎确实会发生一定的变化,但主要是随着气压而变化。密立根认为这些变化用地球大气层吸收能力的涨落... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 总体来说,宇宙空间包含的宇宙辐射很可能会远远多于光和热,虽然在确定这一点的时候我们也必须记得,事实上宇宙辐射是永远不会消失的,而以光和热为呈现方式的普通辐射则会。宇宙中所有物质的完全湮灭将使空间的绝对温度上升10度左右,因此,产生我们观测到的宇宙辐射只需要湮灭掉极小部分的宇宙物质。
英文
遍及空间的宇宙辐射和那些被天文学家们认作是恒星光和热来源的相似的辐射必然是明显不同的,这并不奇怪。恒星内部物质的湮灭会产生频率和观测到的宇宙辐射完全相同的高频辐射,但是当这种辐射向恒星外部温度较低的地方传播并最终到达外层空间时,它会因长期发生连续的康普顿散射而被不断软化,直到最终显现为我们所熟悉的星光形式——从绝对温度1,650度到绝对温度约... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 确实,只有在一个理想化程度非常高的简单恒星结构模型下,动力学结果才能得到严格的证明;但是普遍的热力学原理表明,若在一种结构中,物理状态很小的一个改变就会释放大量的热,那么任何这样的结构都很可能是不稳定的——简言之,它处在一个一触即发的状态。
英文
另一方面,对于恒星辐射是由物质自发湮灭产生的猜想,存在一个有力论据可以反驳它,即如果是在太阳自身原子的自发湮灭中产生了太阳的热量,那么我们是否可以认为地球上的原子也会以相同或者相近的速率自发湮灭。然而计算表明,哪怕湮灭速率仅是这个速率的万分之一,也会使地球非常热,以至于人类无法居住。那么显然,地球内部不可能有明显的物质湮灭。地球必须由不会发生自发湮灭的原子所构成,而如果太阳的热量来自... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | -hydroxybutyric acid, had been isolated. But such quantitative knowledge as existed with regard to the details of oxidation was mainly confined to reactions in which coloured molecules were involved: for example, the reduction of methylene blue to a colourless substance, or the oxidation of p
-phenylene-diamine to a c... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | , where A must be one of a small number of purine bases (it is possible that the same enzyme also activates aldehydes; if so, they are oxidised at about one percent of the rate of the purines). But B may be oxygen, iodine, nitrate, permanganate, or any of a large number of dyes, such as methylene blue. These latter are... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | . There are probably at least seven different ones, and possibly many more. In this case they can readily be shown to be concerned in oxygen uptakes. In certain conditions malonic acid inhibits methylene blue reduction by succinic acid, both uniting with the enzyme at the same point; and in high concentrations of both,... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | They unite not only with O2
but also with CO, for which they have a rather smaller affinity. Like CO-haemoglobins, the CO-oxygenases are generally sensitive to light. Thus the oxygen uptake of yeast in presence of glucose or alcohol is reduced to about 50 percent, in a mixture containing ten parts of CO to one of O2
... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Cytochrome is the name for a group of metal-porphyrin compounds, the metal being probably iron, which are found in almost all cells, and have been studied by Keilin11
. When the cell runs short of oxygen, through asphyxia, intense metabolism, or cyanide poisoning, a strong spectrum of cytochrome, resembling that of a ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | O2
is used for further oxidation with peroxidase, or is destroyed by catalase. The latter can act as a safety-valve owing to its low affinity. Whereas peroxidase acts most rapidly in a concentration of H2
O2
which may be as low as 10–6
M
., catalase has an optimum H2
O2
concentration of about 0.2 M
., and at 10–... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | . The enzymes concerned in both processes have a wide distribution.
中文
Still less is known of how in detail the energy made available in oxidation is passed on, or of how the rate of oxidation is controlled, though both processes are evident enough in the whole organism. The control is largely exercised on the fuel ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | and of biological function. The question of whether these two types of explanation can be reconciled, or whether one of them is superfluous, will then have to be fought out. However, that day is far distant; meanwhile the biochemist can continue to accumulate knowledge without committing himself on philosophical questi... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 另一方面,当相同的化学反应被瓷器催化时,那么两种分子必须被吸附到彼此靠近的位置才能发生反应。
英文
因此,我们无需惊讶于这样的发现,即细胞催化剂不仅能激活氧气,还可以作为乳酸离子等还原剂的激活剂;鉴于沃伯格[1]
和维兰德[2]
分别主张氧气和还原剂的激活作用是呼吸的基本特征,我们将会在这两种理论之间找到一条前进的道路。
英文
参与酶促反应的两类分子中,一种的范围非常有限,而另一种则具有很广泛的适用性,我们将前者称为专一性。狄克逊[3]
和库姆斯[4]
发现,在黄嘌呤脱氢酶催化的反应AH2
+B = A+BH2
中,A必需是少数嘌呤碱中的一种(这种酶也许还可以活化醛基,但是其氧化醛基的效率大约只有嘌呤的百分之... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 在这两种分子存在的条件下,乳酸比甲酸更容易被氧化,而琥珀酸氧化则位于两者之间,这表明可能有三种加氧酶存在,它们像血红蛋白一样对CO和O2
的相对亲和力各不相同,对HCN的亲和力也不相同。每一种脱氢酶都与一个特定系列的加氧酶相关联,因为在甲酸和乳酸存在的条件下,即使加氧酶的活力被HCN抑制,氧气的摄入量也是严格遵守相加性法则的。如果不同的脱氢酶能帮助相同的加氧酶携带等量的活化态氧,那么结果就不会如此。这种严格的组织很可能具有例外,因为大肠杆菌的氧化作用主要发生在其表面而不是内部,另外,大肠杆菌也不含有全部的三种细胞色素。在去除甲苯后,研究人员获得了虽然相似但不很确定的实验结果。
英文
细胞色素指的是金属与卟啉之间形成的一类复合... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 英文
要使这些过程都能有效运行,需要满足两个条件:氧化产生的能量必需略高于合成所需的能量;参与氧化和合成的分子必须结合在相同的催化剂分子上,因此该酶分子必须具有双重特异性。关于这里所说的复杂氧化系统,在弄清它们分别与哪些合成有关之前,人们还不清楚它们的重要性。维尔姆塞首先开展了对这方面的分析研究[14]
。但是此工作的一个必要前提是需要研究各个相互连接的反应中总能量以及自由能的变化,而这些研究尚处于刚刚起步的阶段。
英文
不过,即使我们知道不同物质在氧化反应中所扮演的角色,也知道由此产生的能量是如何使用的,我们还将面临有关调控的问题。毫无疑问,正如机体遵守一些法则来维持心脏的正常功能一样,活细胞中过氧化物酶或乳酸脱氢酶的活... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | exponential is roughly to make the synthesis probability vary as T
20
, or some comparable power, and thus even a change of 1,000 in the fore-factor does not seriously affect T
. The investigation is being discussed fully in the Astrophysical Journal
, but in view of the interest of the subject at present, and also ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | not at all necessary to regard helium as the final product. In fact, since small Z
-values favour synthesis, all the helium formed will be rapidly built up again. The energy developed is roughly the same, however, per proton consumed
, whatever the products.
中文
Since no other theory proposes a lower temperature fo... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | So long, however, as hydrogen is present, synthesis should continue. Since, now, the star's mass remains practically constant, its energy generation must remain moderately so, and it is easily seen that this involves an approximate constancy of the helium supply, but with an ever-present possibility of adding a little ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | In fact, it is easily seen that the most abundant element of all in a star must have an average life (until further synthesis) comparable with the past life of the star itself; otherwise some heavier element would be more abundant. If now we assume the central temperature is so low that oxygen is as long-lived as this,... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | -particles per second as there are helium-lithium syntheses. It is found that the situation which will develop involves a marked minimum between the oxygen and the iron maxima and a marked fall after, say, zinc, in very good qualitative agreement with observation.5
A consideration of Gamow's theory leads us to expect ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | degrees; they should have about the same constitution except for a shortage of hydrogen at the centre, and will be fainter for a given mass.
中文
In addition to these two main classes we may account for the low density giants. These have a comparatively low central temperature and can only obtain their energy (a
) if... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | The “Hertzsprung gap” and its prolongation between the Cepheids and the B
stars may be shown to follow if Be8
has a long life, and its presence on the earth guarantees this. A long life is also in harmony with the Be8
/ Be9
ratio and the He/Be ratio.
中文
A number of other observations may readily be fitted into t... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Russell, Astr. Jour.
, 72
, 11 (1929).
Nature
, 123
, 607 (1929).
原子合成与恒星能量
罗伯特·阿特金森
编者按
在20世纪30年代,人们完全不清楚维持恒星不断发光的能量来源于哪里。威尔士天文学家罗伯特·阿特金森在本文中提出这种能量来源于较重元素在恒星内部的放射性衰变过程。一年后,他的观点被证明是错误的,因为汉斯·贝特发表了一篇关于氢原子可以通过简单的核反应直接聚变成氦原子的报告,当然这个结论只有在人们了解到中子的存在(也是在1932年发现的)之后才能得出。
英文
豪特曼斯和本文作者曾经研究过在恒星内部,质子经由波动力学过程进入核内而引起元素合成... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 在氦供给恒定的条件下,我们可以使用普通的放射性平衡律,即,不同元素的数量应该就相当于它们的“平均寿命”,不管我们面对的是合成过程还是分解过程都不会影响这个定律的有效性。另外,由于原子序数Z
以指数方式影响着合成几率,或者说是平均寿命,所以所有的轻元素都应该非常稀少,但是氧含量比除去氢之外的所有轻元素都要多,而且邻近氧的另外一些元素也至少和铁元素一样丰富。
英文
事实上,很容易看出,恒星中最丰富的元素一定具有与恒星目前的年龄相当的平均寿命(直到后面的合成),否则一些重元素将会更多。如果现在我们假设中心温度很低,以至于氧的寿命就这么长,那么我们就会发现它和更轻的元素仍然会非常丰富以至于仅由它们的合成就可以提供足够的能量,而太阳的... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 许多绿柱石中含有大量的氦,除此之外无法解释为什么有这么多氦,当Be8
的不稳定性刚刚被提出时,瑞利勋爵立刻指出这一发现的重要性[6]
。如果Be8
有很长的寿命,也许可以证明介于造父变星和B
型星的“赫兹伯伦空隙”和它的延长线将是必然的结果,而Be8
在地球上的存在保证了这一假设的成立。另外,较长的寿命也与Be8
/Be9
比以及He/Be比相符合。
英文
一些其他的观测结果也很容易纳入到这个理论中来。我们需要特别提到的是,不存在低密度的中小质量恒星,R
和N
型星在巨星而不是矮星中出现,在一些双星系统中较亮的星会是密度和温度较低的星,并且星团中最亮的恒星通常全部是红的或者全部是蓝的。
英文
强烈支持“... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | , to which they give the formula C18
H21
(OH)3
, is identical with that fully described earlier by one of us (Marrian, 1930)4
. Although Prof. Doisy refers to the triol previously isolated, there is no suggestion in his papers that it had been characterised as a trihydroxy substance of the formula C18
H21
(OH)3
... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 盖伊·弗雷德里克·马里安,阿道夫·布特南特
编者按
在20世纪30年代,科学家们不仅从事于维生素的鉴定,也进行激素的鉴定。它们是生命活动必需的基本化学物质,激素能由动物体自身合成,而维生素则必须通过食物供给。本文描述了一种诱导动物发情的激素的分离。作者阿道夫·布特南特是德国当时最受人尊敬的化学家之一,他曾于1939年获得了诺贝尔化学奖。催情激素及其类似物是计划生育药物的常规成分。
英文
最近,多伊西及其同事(1931年)报道说他们从孕妇尿液中分离出一种具有催情活性的结晶性物质,该物质不同于他们之前提到的活性物质雌酮。之前提到的物质的化学式被他们定为C18
H21
(OH)2
,这种物质随后被我们中的一位作者(布特南特... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | -particles into the same excited level rather than to the excitation of one α
-particle into several excited levels. Their arrangement of the lines of radium C' is probably not a unique scheme of this sort, but any reasonable scheme appears likely (they show) to present the same general features.
中文
It seems desira... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | . This model is obviously a rather poor physical approximation to the type of force, but it has the advantage that it can be studied exactly and not merely by the approximations of a perturbation method. A discussion of both these models has been begun, but has as yet only been carried through for the first model simpl... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | -rays of other atoms have not yet been analysed in this way.
中文
All these features are general and the conformity very reassuring. One can, however, further estimate the relative frequency of the emission of the various γ
-rays corresponding to the transitions from a state of q
-excited α
-particles to states of ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | back from the γ
-ray intensities to some knowledge of the magnitude of these triple and higher interactions.
中文
To sum up, one may say that the scheme proposed by Rutherford and Ellis, so far as it has yet been closely analysed, that is for frequencies only
, seems likely with trivial modifications to conform comp... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | In the models suggested above, the effect of the protons has been ignored primarily because there seems at present no simple way of incorporating them. But it is clear that the general effect of free protons present in normal and excited states will be to cause the set of low frequency transitions q
→q
–1 to be repea... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 模型中由多个α
粒子跃迁到同一个激发态上所产生的能级具有这样的形式,即相应的γ
射线(如果所有γ
射线都被能放射出来)的频率大致为:
hv
=p
(E
0
–qE
1
)
如果将卢瑟福与埃利斯的构想稍加修正,由此得出的射线频率将和上式中的射线频率吻合得很好。因此我们用频率关系对应于2(E
0
– qE
1
)和2(E
'0
– qE
1
)的两组γ
射线代替以前提出的频率关系对应于2E
0
– qE
1
的单组γ
射线,其中,E
0
和E
'0
几乎相等。我们还用频率关系对应于3(E
0
– qE
1
)、3(E
'0
– qE
1
)和3(E
′′0
– qE
1
)的三组γ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 英文
在上面所提出的模型中,质子的效应从一开始就被忽略了,因为目前似乎还没有将质子效应整合到模型中的简单方法。但是可以明确的是,在正常态和激发态,由自由质子所引发的普遍效应会使低频跃迁q
→q
–1在高频情况下重复发生,但是高频情况下的跃迁同样依赖于q
,两种情况下的常数变化代表了一个质子的激发能。
英文
(王静 翻译;李军刚 审稿)
The Angular Momentum of Light
C. V. Raman
Editor's Note
Arthur Compton's pioneering work on the scattering of light by electrons showed how t... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Actually, a remarkable simplicity characterises the observed spectra of the light scattered by polyatomic molecules, a simplicity which is in striking contrast with the complexity of their absorption and emission spectra. It is clear that the Compton principles cannot be regarded as capable of predicting
the observed ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | of the same result.
中文
It is remarkable that the latter result is also predicted by the classical electromagnetic theory of light for the case of a rotating anisotropic particle scattering circularly polarised radiation. Nevertheless, it is clear that the observed phenomena may be regarded as an experimental proof t... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 英文
(沈乃澂 翻译;张泽渤 审稿)
Isolated Quantised Magnetic Poles
O. W. Richardson
Editor's Note
There were, in classical physics, no “magnetic charges”—no isolated magnetic poles without their complementary pole. But Paul Dirac suggested that quantum theory might allow the existence of such “monopoles”, and here distinguished ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | be fixed by an argument based on classical ideas at about 500 times that of the corresponding electronic object. Following this general line of argument, the dimensions of these magnetic atoms come out at 10–14
cm. to 10–15
cm. compared with 10–7
cm. to 10–8
cm. for the atoms of the periodic table. The frequencies ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | There may be an application of these products of the quantum theory in the field of “ultra-penetrating” radiations. I have no first-hand knowledge of the process of creation, but I should suspect it would be relatively difficult to create objects with the intrinsic energy of these magnetic poles. It seems likely, there... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 我对孤立磁极的形成过程没有直接的了解,但我推测,产生这种具有磁极内能的物质是相当困难的。因此,地球上磁原子的数量似乎应该远小于电子和质子的数量,但在宇宙中磁原子的数量也许已经足以用来解释超穿透辐射这种不能用其他方法解释的现象。如果这类与电子和质子的性质差异很大的孤立磁极是存在的,那么将会使许多宇宙问题的研究思路发生明显的变化。
英文
(沈乃澂 翻译;赵见高 审稿)
The Biological Nature of the Viruses
*
H. H. Dale
Editor's Note
As late as the 1930s, the properties of the viruses appeared to b... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | analogous to that in which we speak of a living enzyme, with the important addition that they can multiply themselves indefinitely. Some, however, would attribute this, not to actual self-multiplication, but to a coercion of the infected cells to reproduce the very agent of their own infection.
中文
The problems prese... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | mosaic disease of the tobacco plant, brought to general notice and greatly developed by Beijerinck's work on the same infection some seven years later; and with Loffler and Frosch's demonstration, in the same period, that the infection of foot-and-mouth disease is similarly due to something microscopically invisible, a... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | based on negative characteristics, must obviously narrow its scope with the advance of technique. We may look a little more closely at the meaning of these different characters.
中文
Microscopic visibility is obviously a loose term. Rayleigh's familiar formula, in which the lower limit of resolution is equal to one-ha... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | success of its cultivation on artificial media. Visibility seems to have rendered doubtful the position of the Rickettsia group of infections, and, if the test is logically applied, the process of exclusion can scarcely stop before the agents transmitting psittacosis, fowl-pox, infectious ectromelia, and even vaccinia ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | and admittedly hasty tendency to identify them as infective protozoa, opinion seems to have swung too quickly to the opposite extreme, of dismissing them as mere products of the infected cell. It is so comparatively simple, in some cases, to separate these bodies, that it is surprising that so few efforts have been mad... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 中文
For these reasons a good deal of the evidence showing that certain viruses can be detected in the filtrates, obtained with filters which will not allow haemoglobin to pass in perceptible quantities, must be regarded at least with suspicion. Dr. Elford has recently succeeded in preparing filter-membranes of much gre... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | that at which their units are apparently becoming clearly visible by modern microscopical methods.
中文
It will be clear, indeed, that, if we accept the lowest estimates for the size of the units of some viruses, such as the bacteriophage and the agents transmitting some plant diseases, we cannot by analogy apply the ... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | constituents of a lifeless medium; the energetics of such a process might present an awkward problem. To account for the multiplication of such a substance at all, even in cells infected by it, we should be driven, I think, to the hypothesis which has been freely used to account for the propagation of bacteriophage, on... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | difficult, again, to imagine that a virus like rabies could be permanently excluded from a country if it had such an autogenous origin. The phenomena of immunity to a virus, and of closely specific immunity to different strains of the same virus, are peculiarly difficult to interpret on these lines.
中文
This concepti... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | different kinds. If we approach the series from one end, and watch the successive conquests of microscopical technique, or if we consider the phenomena of immunity over the whole series, we are tempted to assume that all the viruses will ultimately be revealed as independent organisms. If we approach from the other end... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Our evidence of the vitality of its particles is, as yet, entirely due to their behaviour after transmission. They may accordingly contain protein, lipoid and other molecules in a state of such dense aggregation that comparisons of their size with that of the heavily hydrated molecules of a protein in colloidal solutio... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 我们能够合情合理地归为生命的最低组织化程度是什么?能够包含生物体最小组织的最小空间有多大?有组织、能分化以及通过一层特殊性质的界膜与周围基质分离是否是具有任何形式的生命体所必备的特征?或者是否可以设想它是一种物质复合体,保持了无穷尽地复制的生理特征,正如被感染细胞做出的高度特异性的反应一样,尽管它不是组织有序的单位,而是均匀地分散在了含水的介质中?对那些把病毒作为主要致病因子来研究的人来说,这些问题是争论的焦点;我认为这些是生理学家更应该关注的问题。
英文
我无法阐述有关这个话题的历史;但值得注意的是,早在有任何提示显示可见的细菌和疾病有什么联系之前,爱德华·詹纳在天花以及牛痘治疗中就研究过这个问题,这种病我们现在认识到是典型... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 同时,这是一个假设程度的问题,在假设上存在不同的观点是合情合理的。我们要认识到证据并不完美,但是也要谨防打倒一切的怀疑论。我猜想一些评论家的态度受到过去探索病毒的历史,尤其是与被称为“包涵体”的神奇物体有关的那部分历史的影响。“包涵体”是在受某些特定病毒感染后的动植物细胞内发现的,在分辨率相对较低的显微镜下就可以轻易观察到。最开始大家草率地倾向于把它们看作是传染性的原虫,但很快,观点转换到了另一个极端,即认为它们不是单纯的受感染细胞的产物。在一些试验中,分离这些包涵体是如此的容易,以致于很奇怪几乎没有人研究它们的感染性。但是,已经发现这样一种包涵体具有至少可以传播一种病毒感染的能力;在其他一些试验中,进一步发现它们是由无结构的基质包... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | 另一个类比,可能更贴切,是在最近的试验中发现的,即去除肺炎球菌培养液中的类型特异性碳水化合物后,该球菌能够获取另外一种类型的碳水化合物,然后以新的类型不断繁殖,这样就人为地产生了一种新的特异性类型。动物的免疫细胞在接触了外源蛋白后的反应可能也是一种类似的机制,这种通过改变代谢产生免疫的反应经常会持续一生,但是这种保护性反应恰恰抑制了被病毒感染的细胞的复制。
英文
博伊科特再次强调:要在能够促进细胞增殖以便修复损伤的正常细胞成分和传播恶性肿瘤或引发口蹄疫的病毒之间划一条清楚的界线是很困难的。我个人认为,在普通生物学背景下很难接受这样一个观点,即一个具有自身代谢能力的细胞会立即转向产生破坏自身的物质或者异常刺激。这几乎是免疫反应的... | 400套付费套装书 |
C:\Users\yuan\Documents\400套付费套装书\04-100套\epub\0301. 《自然》百年科学经典（第二卷）(英汉对照版)(1931-1933).epub | .epub | 11,771,588 | 2025-09-26T19:06:58.142679 | Maxwell and Modern Theoretical Physics
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N. Bohr
Editor's Note
On the occasion of the Maxwell Centenary Celebrations in Cambridge, October 1931, Niels Bohr presented an address on Maxwell and Modern Theoretical Physics. Bohr notes that Maxwell's theory of electricity and magnetism had made possible developments in t... | 400套付费套装书 |
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