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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 | This assumption means that the superconductivity must be destroyed when the energy of the external forces exceeds the energy of the “spontaneous coupling”. Form (1) we may calculate H
0
for lead and tin, and compare them with the experimental results.
中文
中文
According to the recent experiments of McLennan and his... | 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 | 凯索姆与范登恩德[1]
,以及西蒙与门德尔松[2]
都试图去揭露铅的比热在超导转变温度(7.2 K)附近的这种反常行为,但是他们都未能探测到这种行为的任何迹象。该结果也许可以从两个角度来解释:要么是由于超导体中导电电子的“自发耦合”假说是完全错误的,要么就是由于在传导性中计入的电子的数目较之原子的数目而言太小,以至于无法用量热法探测出由传导电子引起的比热反常。
英文
正如我们的测量结果所表明的那样,铁磁体在居里点的比热反常表现在热电效应(汤姆孙效应)上是非常显著的,以至于尽管有关此效应的正负号确定还存在一定的困难,但由纯热电常数计算出来的比热反常的数量级与量热法的测量值还是符合得很好。人们很自然地想到将这种方法用于超导性领... | 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 | INCE the publication of our paper1
on the disintegration of elements by fast protons, we have examined some of the light elements more carefully, using much thinner mica windows than we had previously employed on the high voltage tube. With the present arrangement, we can count particles which have passed through only... | 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. There also seem to be present a small number of particles with ranges up to about 5 cm.
中文
(131
, 23; 1933)
J. D. Cockcroft and E. T. S. Walton: Cavendish Laboratory, Cambridge, Dec. 22.
Reference:
Proc. Roy. Soc
., A, 137
, 229 (1932).
快质子引起的轻元素衰变
约翰·道格拉斯·考克饶夫,欧内斯特·瓦耳顿
编者按
考克饶夫和瓦耳顿改进了对于高能质子与轻元素... | 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 | N conformity with the hypothesis, for which there is at present no experimental basis, that the ovarian hormones are formed by degradation of sterols, and in the light of recent developments in the chemistry of the sterols, ketohydroxy-oestrin is possibly represented by formula (i).
This accords with all the facts sup... | 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 | animals just short of the definition (a few leucocytes). In a series of twenty animals injected with 100 mgm. dissolved in sesame oil, a very much better response was obtained, all twenty animals going into oestrus. The oestrus in each case was complete.
中文
In the case of the 50 mgm. dosage, oestrus appeared after 5... | 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 oestrogenic properties of a low order are possessed by suitable extracts of such a variety of materials as peat, brown coal, lignite, coal tar and petroleum is of interest, but in view of the fact that many such materials are known to contain carcinogenic constituents, the clinical use of such extracts without ver... | 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 | 而且每只大鼠的发情反应都是完全的。
英文
当剂量为50 mg时,发情反应在54个小时后出现,并于150个小时后终止。在以100 mg该物质溶于芝麻油的实验中,发情反应出现于52个小时之后。目前,我们还不能把该物质的活性与雌激素的活性进行比较,原因是该物质溶解性较差以及由此引发的给药和吸收上的困难。因此必须引入某种“交叉”的方法。毫无疑问,重复进行将50 mg该物质溶于少量芝麻油的标准化实验会比以橄榄油为介质的类似实验效果更显著。
英文
观察表明:当给阉割的动物注射催情药物时,使用1–酮–1, 2, 3, 4–四氢菲产生的效果与注射雌激素非常相似。这一结果意义重大,因为1–酮–1, 2, 3, 4–四氢菲是人们发现的第一个... | 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 | composition they are peculiar in containing a very high percentage of silica (SiO2
, 70–89 percent).
中文
Many theories have been advanced to account for the origin of these bodies, which are known collectively as tektites. Those from Bohemia and Moravia were formerly thought to be relics from a prehistoric glass fac... | 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 | consist of such a silica-glass. The vesicular white glass contains SiO2
, 92.88 percent, with specific gravity 2.10 and refractive index 1.468; whilst the black glass, almost free from bubbles, contains SiO2
, 87.45 percent, with specific gravity 2.24 and refractive index 1.50. The black glass contains also Fe2
O3
... | 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 I have seen pictures of the tektites from Indo-China given by Prof. Lacroix in his monograph, I have no hesitation in concluding that tektites are not meteoric, though they are connected with the fall of large meteoric masses, but that they have resulted from the fusion of terrestrial rocks, especially in sandy de... | 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 | Billiton, where by slow chemical corrosion they have acquired a peculiar sculptured surface. The australites found on the surface of the Australian deserts do not show this surface sculpturing and are more perfect in form. They are therefore of more recent origin. An aerial survey of the districts where australites 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 | 黑色硅质玻璃中还含有0.28%的Fe2
O3
,5.77%的FeO以及0.35%的NiO。在这里还发现了铁陨石碎片,最大的铁锈残片重达25磅;还有一系列由大量流星雨撞击地球所形成的陨石坑。当以行星运行速度飞行的大块铁陨石突然停止运动时,其动能
就会在局部的一个点上转化为热能,进而达到很高的温度。菲尔比先生在瓦巴地区收集到的硅质玻璃“弹”说明:在荒漠的砂石中一定存在着一片熔融的硅层,这些硅层中的物质在陨石撞击地球时被从陨石坑中抛射出来,随后穿过充满二氧化硅、铁和镍蒸气的气团。
英文
1931年,人们在澳大利亚中部的亨伯里附近发现了陨石坑群[3]
,在其中也发现了硅质玻璃,不过数量较少,并且仅存在于规模最大的陨石坑周围。这... | 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 | sec.-1
As Regener notes, a body in thermal equilibrium under illumination from this flux would bear a temperature of 3.1 K, similar to Arthur Eddington's result for a body in equilibrium with the ordinary radiation coming from stars.
中文
I
N Nature for September 3, 1932, p. 364, I published the curve of the intensi... | 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 | finds for a black body heated only by the heat and light radiation of stars. Eddington's calculation relates to a point in our local system of stars, but not in the neighbourhood of one of them. If at such a point the flux of energy of cosmic radiation is equal to that on the earth, the temperature of a black body, abs... | 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 | 爱丁顿的计算仅关系到我们所处的局部恒星系统中的一个点,而不涉及其中某一个恒星的周边区域。如果在这样一个点上,宇宙辐射的能流与在地球上获得的能流相等,那么根据T
4
定律,一个完全吸收了这两种
辐射后的黑体的温度只会升至3.7 K。但对于处于旋涡状星云内的空间某一点来说,通常的辐射是非常小的,所以温度上升的幅度也微乎其微。假设宇宙射线起源于这样的星系际空间,它们将引发与宇宙射线通量相对应的升温现象。
英文
更详细的结果将在近期的《物理学杂志》上发表。
英文
(史春晖 翻译;马宇蒨 审稿)
Helium Liquefaction Plant at the Clarendon Laboratory, Oxford
F. ... | 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 easy to design apparatus so that the substances the properties of which at low temperatures are under investigation, are cooled to the temperature of the surrounding liquid or solid helium and maintained at this temperature with a minimum of waste. It seemed preferable, therefore, to instal a small inexpensive ap... | 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 | When temperature equilibrium has been attained, hydrogen is introduced into the top vessel under a pressure of two or three atmospheres. Passing through the copper spirals, this liquefies owing to the excess pressure and runs down into the metal container over the double-walled helium cylinder. A tap to the mercury vap... | 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 liquid hydrogen required is produced in a plant of the standard pattern designed in the Physico-Chemical Institute in Berlin which has been in use at Oxford for some years now without giving any trouble. Impurities in the hydrogen are condensed by a preliminary expansion and continuously removed by a slow stream 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 | 在20世纪30年代早期,液氦对于研究很低温度下物质性质的物理学家来说是十分珍贵的。在本文中,牛津大学的物理学家弗雷德里克·林德曼及其同事宣布研发出了一种能生产大量液氦的新方法。他们采用突然改变液态氢压力的方式来冷却氦,可以用这种较便宜的装置连续地得到大量的液氦。他们的实验室持续生产了1.5个小时的液氦。正是这一方法及接下来的一些发展使俄罗斯物理学家彼得·卡皮查得以在1938年发现液氦中的超流性现象。
英文
多年以来,液氦的主要性质就已为科学界的人士所熟知。所以人们把氦液化的唯一目的,是想用它来冷却其他物质以便研究它们在绝对零度附近的性质。长期以来人们就知道,固体的热容量在低温时会变得非常小。因此,蒸发20毫克液氦吸收的潜热足以... | 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;陶宏杰 审稿)
Structure and Division of Somatic Chromosomes in Allium
T. K. Koshy
Editor's Note
When T. K. Koshy published this account of Allium
chromosomes separating in 1933, there were three competing theories of chromosome structure—the nuclear components were either granular, spiral or shaped like hone... | 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 | has been undertaken under the kind guidance of Prof. R. Ruggles Gates, with the view of solving some of these problems. A preliminary account of the results so far obtained by cytological observations and the use of wire models is given below.
(1) At the early metaphase each chromosome is seen to be composed of two spi... | 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 | Further work on this subject is in progress and it is hoped that a detailed account may be published at a later date.
中文
(131
, 362; 1933)
T. K. Koshy: King's College, London, Feb.7.
References:
Hedayetullah, J. Roy. Mic
. Soc., 51
, 347-386.
Perry, J. Roy. Mic
. Soc., 52
, 344-356.
葱属植物体细胞染色体结构与分裂
科希
编者按
... | 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 | Ernest Rutherford here offers a snapshot of the rapidly advancing field of nuclear transmutation. It had been established that many atoms can be changed from one element to another by adding or subtracting any of the various particles believed to inhabit the nucleus. But so far no such reactions had been observed with ... | 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 | -particle. The types of transformations produced by the neutron are thus very different from those observed with the α
-particle. The capture of an α
-particle in general leads to the building up of a new nucleus three units heavier than before, while the capture of a neutron leads to the formation of a nucleus three... | 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. The radiation observed is complex, and has not yet been analysed in detail. A number of other elements have been found to be transformed, apparently in all cases with the emission of α
-particles.
中文
In a special form of accelerating tube devised by Oliphant in the Cavendish Laboratory, a narrow, intens... | 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 | During the last few years, much energy has been devoted throughout the world to developing methods of obtaining streams of very swift charged particles with which to bombard matter and effect its transmutation. In the apparatus of Cockcroft and Walton at Cambridge already referred to, a steady potential of 800,000 volt... | 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 | negative electron of light mass.
中文
(131
, 388-389; 1933)
*
Substance of the Friday evening discourse delivered at the Royal Institution on March 10.
关于元素嬗变的最新研究
*
欧内斯特·卢瑟福
编者按
欧内斯特·卢瑟福在这篇文章中发表了对快速发展的核嬗变领域的简评。已经确认许多原子都可以通过增加或减少核中的任意粒子使自己从一种元素转变成另一种元素。但迄今为止人们在像铊、铅、铋和铀这样的重元素中还没有观察到这种反应。卢瑟福说:这个结论可能会有所改变,因为全世界的物理... | 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 | 他们还在构建更大的装置,以期获得15百万伏的电压并将之应用到大的真空钢筒内。布拉什和兰格已将瞬时高电压通过脉冲发生器加到放电管上。
英文
加州大学的劳伦斯发明了一种新的直接多次加速的巧妙方法,他用小于10,000伏的电压得到的质子能量为1.5百万伏。在使用约千分之一微安的质子流时,锂在这种高能下发生的嬗变得到了检验。这类方法被寄予厚望,因为它可能获得高达10百万伏甚至更高能量的质子。
英文
即使这些新方案被证明是成功的,由它们产生的粒子速度仍远小于我们在大气层中观测到的穿透力很强的辐射,大气中电子和质子的能量在200百万伏到2,000百万伏之间。帕萨迪纳的安德森及剑桥大学的布莱克特和奥基亚利尼的实验似乎表明,这些非常快的... | 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 | , in which a commercial variety of maize was exposed to mass selection from year to year in two diverging lines for high and low protein, and in two more for high and low oil content. For protein the initial value was about 11 percent with a standard deviation of a little more than 1 percent, but in the average of 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 | occurrences.
中文
The results obtained with oil-content have been even more striking; for the high oil line now contains nearly six times as much as the line selected for low oil content, and differs from it by more than twenty times the original standard deviation. “Student” uses these data, together with reasonable ... | 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 should be emphasised that the result of importance for evolutionary theory is not that the number of factors must be very large, thousands for example, rather than hundreds, but the direct demonstration that selection has the exact effects that selectionists have ascribed to it, without the limitations by which 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 | 我相信,这个特殊实例驳斥了在玉米育种者中流传的认为细微差异对选择无效的种种学说,而这些论点在一开始就阻碍了现代遗传学的教学。
英文
应当强调的是,进化理论的重要结论并不在于因子数量一定要很大,比如是数千个而非数百个,而是在于它直接证明了选择具有自然选择论者所认为的确切效果,它的作用并没有受到人们一向认为会有的限制,而这些限制是由于早期人们对累积效应下孟德尔因子的数量和变化的误解所产生的。
英文
(周志华 翻译;刘京国 审稿)
Light and Life
*
N. Bohr
Editor's Note
This is an address given by Niels Bohr at the Internatio... | 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 | S a physicist whose studies are limited to the properties of inanimate bodies, it is not without hesitation that I have accepted the kind invitation to address this assembly of scientific men met together to forward our knowledge of the beneficial effects of light in the cure of diseases. Unable as I am to contribute 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 | phenomena, exhibits an analogy to life, the diversity of which is far beyond the grasp of scientific analysis.
中文
From a physical point of view, light may be defined as the transmission of energy between material bodies at a distance. As is well known, such an energy transfer finds a simple explanation in the electr... | 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 of the wave nature of the propagation of light, that this conception can no longer be considered as a hypothesis in the usual sense of this word, but may rather be regarded as an indispensable element in the description of the phenomena observed.
中文
As is well known, the problem of the nature of light has, neve... | 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 spatial continuity of light propagation, on one hand, and the atomicity of the light effects, on the other hand, must, therefore, be considered as complementary aspects of one reality, in the sense that each expresses an important feature of the phenomena of light, which, although irreconcilable from a mechanical p... | 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 | characterised the atomic theory, to be sure; and this fact is not essentially altered, although the development of physics has replaced the indivisible atoms by the elementary electric particles, electrons and atomic nuclei, of which the atoms of the elements as well as the molecules of the chemical compounds are now s... | 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 recent years, a remarkable development of the atomic theory has taken place, which has given us such adequate methods of computing the energy values for the stationary states, and also the probabilities of the transition processes, that our account, on the lines of the correspondence argument, of the properties 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 | never possible to take the interaction between object and measuring instruments directly into account. For the instruments cannot be included in the investigation while they are serving as means of observation. As the concept of general relativity expresses the essential dependence of physical phenomena on the frame 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 | of photo-chemical processes must undoubtedly be taken into consideration. Likewise, the peculiar stability of atomic structures is clearly exhibited in the characteristic properties of such highly complicated chemical compounds as chlorophyll or haemoglobin, which play fundamental rôles in plant assimilation and animal... | 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 | with a suitable amplifier so as to make the individual processes observable. It is true that it is possible by such instruments essentially to increase our powers of observation, but, owing to the very limits imposed by the properties of light, no instrument is imaginable which is more efficient for its purpose than th... | 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 | hand, this view, often known as vitalism, scarcely finds its proper expression in the old supposition that a peculiar vital force, quite unknown to physics, governs all organic life. I think we all agree with Newton that the real basis of science is the conviction that Nature under the same conditions will always exhib... | 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 tracing this analogy further, however, we must not forget that the problems present essentially different aspects in physics and in biology. While in atomic physics we are primarily interested in the properties of matter in its simplest forms, the complexity of the material systems with which we are concerned in bio... | 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 | atomic mechanics would be misleading, if, as in common language, we should apply the word mechanics only to denote an unambiguous causal description of the phenomena.
中文
I shall not here enter further into these purely logical points, but will only add that the essence of the analogy considered is the typical relati... | 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 will carry us too far from our subject to enlarge upon this analogy which, when due regard is taken to the special character of biological problems, offers a new starting point for an elucidation of the so-called psycho-physical parallelism. However, in this connexion, I should like to emphasise that the considerati... | 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 | been a hindrance to the wonderful advances which have been made in recent times in all branches of biology and have, not least, proved so beneficial in the art of medicine. Even if we cannot make a sharp distinction on a physical basis between health and disease, there is, in particular, no room for scepticism as regar... | 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 | 但我马上要说明的是,光这种在物理学中可能是最不具有复杂性的现象,只是在这一点上与多样性远远超出科学分析范畴的生命现象相似。
英文
从物理学的观点看,光可以被定义为相隔一定距离的物体之间的能量传播。大家都知道,利用电磁学理论就可以简单地解释这样的能量传递,这也许可以被看作是对包括超距作用和接触力在内的经典力学的直接拓展。根据这一理论,光可以被描述为耦合的电磁振荡,它们与无线电广播中使用的普通电磁波一样,只不过具有较高的频率和较短的波长。事实上,我们之所以可以通过直接观察或适当的光学仪器来判断物体的位置是因为光具有直线传播的特性,而这种特性完全依赖于光的波长比相关物体和观测工具的尺度要小很多。
英文
然而,光具有波动性的思想... | 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 | 此外,因为在一个原子发射光或吸收光的跃迁过程中只会有一个光量子产生或消失,所以我们能够通过光谱观测直接测量每一个定态的能量。人们通过对原子碰撞和化学反应中能量交换的研究已经非常有效地确证了由上述方法得到的数据。
英文
近些年来,原子理论取得了长足的进步,它足以为我们提供计算定态能值和跃迁几率的方法,因而我们根据一致论得到的有关原子性质的结论在完整性和自洽性方面几乎与用牛顿力学解释天文观测结果的水平不相上下。虽然只有在引入新的符号处理技巧之后才有可能合理地解决原子力学的困境,但在分析光学现象时的经验对于我们评估原子力学的发展仍然有非常重要的意义。因此,确立定态概念是对用力学法分析原子内部运动的补充;同样,引入光量子概念是对电磁辐... | 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 | 因此,我们要讨论的问题是,在我们能够用物理学观点解释生命现象之前,是否还缺少一些分析自然现象所需的基本特征。如果不去考证我们通过物理学解释而理解的内容,就很难得到这个问题的答案,更何况现实中生物现象的类别多得无法列举,这要比发现作用量子对我们的推动意义更深远。一方面,通过生理学研究不断揭示出的神奇特征与无机物的特征有着显著的差别,这使许多生物学者怀疑用纯物理学的方法是否可以真正理解生命的本质。另一方面,人们通常称为活力论的观点,不能正确地解释有一种特殊的生命力掌控着所有有机体的古老假设,在物理学中也不存在这样的力。我认为我们都赞同牛顿的观点,即科学的真正基础在于确信自然界在相同条件下会表现出同样的规律性。因此,如果我们能够把对生命体... | 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,依据我们的观点,意志对自由的感受必须被看成是意识生活所特有的性质,人们必须在器官的功能中寻找与其对应的物质,既不允许力学因果描述也不能允许充分彻底地运用原子力学中的统计规律来进行物理学研究。除了形而上学的思索以外,我也许可以补充说,所有对一个解释的概念的分析都以放弃对我们自身意识行为的解释开始,也以放弃对意识行为的解释而结束。
英文
最后,我想强调的是,我并不希望大家把我的话理解为是对未来物理学和生物学发展的怀疑。实际上,现在这个时代的物理学家绝不会抱有怀疑论的思想,因为科学已经在人们认识到最基本的概念存在局限性的基础上发生了深刻的变革。近期人们在生物学所有分支取得的惊人进展并没有受到放弃对生命问题本身的解释的影响,而且... | 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 | . If we approximate this model by a rectangular hole with infinitely high walls, the energy levels of a moving particle will be determined by the roots of Bessel functions and can be easily calculated. For the real model, however, this theoretical level system will be deformed owing to the fact that the walls are neith... | 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 | -transitions, four fall in a spectral region not yet investigated and four are not observed, possibly due to comparatively small intensity. It is also of interest to construct an excitation diagram, building up the sums of the intensities for all lines crossing a given level interval. From this diagram we see that ther... | 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;尚仁成 审稿)
New Evidence for the Positive Electron
J. Chadwick et al.
Editor's Note
Here James Chadwick, along with Patrick Blackett and Giuseppe Occhialini, confirms the existence of a positively charged anti-particle of the electron, initially reported by Carl Anderson from cloud-chamber experiments. Chadw... | 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 and neutrons, emitted from the beryllium. Expansion photographs were taken by means of a stereoscopic pair of cameras. A magnetic field was applied during the expansion, its magnitude being usually about 800 gauss.
中文
Most of the tracks recorded in the photographs were, from the sense of their curvature, clear... | 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 manner in which these positive electrons are produced is not yet clear, nor whether they arise from the action of the neutron emitted by the beryllium or from the action of the accompanying γ
-radiation. It is hoped that further experiments now in progress will decide these questions.
中文
Our thanks are due 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 | 英文
(王锋 翻译;李军刚 审稿)
The Physical Nature of the Nerve Impulse
*
A. V. Hill
Editor's Note
Following a lecture he had recently given at the Royal Institution in London, Nobel Prize-winning physiologist Archibald Hill here explains the nature of nerve impulses. This is one of the earliest examples of a biological proble... | 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 | respectively it is stated to be 0.2 metre and 0.05 metre per second. The velocities in this list are in the ratio of 2,000 to 1.
中文
The nerve impulse is an event, a wave, a propagated disturbance, not a substance or a form of energy. It is transmitted along a thread of protoplasm which, in medullated nerve, is surro... | 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 | Let us consider the properties of the impulse which is transmitted, or transmits itself, in nerve. The single impulse in the single fibre is the basis of nerve activity. Until recently, this individual impulse could not be separately examined and deductions had to be made from the results of stimulating many fibres in ... | 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 impulse at any instant occupies a few centimetres of the fibre. This length is not much altered by a change of temperature and it is approximately proportional to the diameter of the fibre. There must be some simple physical reason for these facts, as also for the next one. (G
) The velocity of the impulse is al... | 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 | heat production one millimetre of steady deflection corresponds to a rate of heat production of about 2×10–8
calorie per second.
中文
The heat is produced not only during the passage of the impulse but for a long time afterwards
; some kind of breakdown occurs, presumably as the wave goes by. This breakdown has then... | 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 initial heat is the result presumably of some chemical reaction involved in, or immediately after, the transmission of the impulse. If we suppose the reaction to occur throughout the substance of the axis cylinder, its heat is so small that it is difficult to picture any mechanism by which the change could be prop... | 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 | as 0.05 we should require a capacity of the order of half a microfarad per square centimetre of nerve fibre surface to give us the observed initial heat. There is some evidence that capacities of this size may possibly exist at the surface of living cells. If so, we should not need to look for a chemical reaction to ex... | 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 | Stimulation and lack of oxygen, however, are not the only means by which the potential difference can be reduced. There is normally a ratio of about 10 to 1 between the inside and the outside of a crab's nerve fibre in respect of potassium ion concentration. If we suppose that potassium is the only substance capable 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 | by admitting oxygen, it shows in a striking manner a typical veratrine effect. The action current lasts hundreds of times as long, the heat production is thousands of times as great, as in the normal response of a nerve to a single shock.
中文
Apparently the drug is usually unable to penetrate the nerve fibre sheath. ... | 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 | neuro-muscular junction. At this point the medullary sheath is absent. Perhaps a nerve dosed with curare but apparently unaffected, might be found effectively poisoned after asphyxiation.
中文
The experiment was performed by Fromherz: a muscle nerve preparation was paralysed by soaking in curare, the nerve was removed... | 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 nerve, the time required at any point for the action current to go through its cycle, the time taken in the transmission of the impulse, and the time-scale (to which I will refer later) of electric excitation, all can be varied together as we alter the condition of the cell or pass from one cell to another. These ar... | 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 | (0.001 sec.): vertically minimum strength required.—From “Chemical Wave Transmission in Nerve”, by A. V. Hill (Cambridge University Press, 1932).
中文
In the case of nerve this curve is always approximately of the same form and may be defined by two parameters, the scale of time and the scale of current. The latter is ... | 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 too high a frequency the case is different. An impulse starts off from the cathode for each positive phase of the current, another from the anode for each negative phase. This is true up to, say, 300 a second for a frog's nerve, 700 a second for a mammalian nerve. When, however, we consider the case of a much highe... | 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 | frequency, however, or with a constant current, while the first effect is still to charge the condensers, as these are charged a difference of potential arises across the dielectric by which a current is caused to pass. When this current reaches a sufficiently high density outwards at the cathode, instability is produc... | 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 | If the excitation time be determined by the product of the capacity and the resistance per square centimetre of nerve fibre surface, then we should seek to explain the differences between different fibres, or between the same fibre under different conditions, by changes in the product Fr
. The thinner the sheath the g... | 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 might effectively prevent the further transfer of current at a time when the externally applied E.M.F. at last reached the value at which, if suddenly applied, it would excite.
中文
Similarly, we may explain the stimulus occurring at the anode at break of a long-continued constant current. During the prolonged... | 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 | Some years before the War, Keith Lucas showed that in muscle there are two different excitable substances which he supposed were the muscle fibres themselves and the nerve twigs running to them. Lucas's experimental demonstration was denied by Lapicque who, employing different electrodes, found that the excitation time... | 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 Propagated Disturbance
We have considered the manner in which excitation by an electric current occurs. With every adjustment made to get the most efficient stimulus, the energy in it is still very large when compared with that set free by the nerve itself as an impulse runs along it. Electrical stimulation is very... | 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
It must not be imagined that this self-perpetuating electro-chemical wave is analogous to those waves in physics in which no new energy is required from point to point for the transfer of the wave. In sound, or in light, energy is forced into the medium at the source but no further energy is required for the propag... | 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 chemical reactions occurring in muscle are largely those of recovery. Lactic acid formation is involved in the restoration of creatine phosphoric acid which breaks down in activity; oxidation and the combustion of food-stuffs are involved in the restoration of the lactic acid. In nerve we know that in any case nine... | 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 yeast cells prepared in a special manner are held in a suspension which is placed in two tubes, an experimental and a control. The experimental tube is exposed through its open end to the radiation in question, the control is kept without radiation. At the end of the exposure, samples are taken and incubated, and 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 | When we remember that maximal continuous stimulation of nerve does not double its resting metabolism, the variety and strength of the radiation emitted from active nerve, under the comparatively mild stimuli administered to it, are rather astonishing. A vague suspicion that the results are almost too good to be true is... | 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 | afternoon and at five in the afternoon. The blood was dried on filter paper, then dissolved in distilled water and finally allowed to give out its radiation, which was measured as usual by the yeast cells. At eight in the morning the mean value of the radiation coming from their blood was 28, as measured by the percent... | 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 | changes in it are too small for ordinary chemical methods to detect. If the new methods elaborated by our Russian colleagues can throw real light on the subject, then we shall be deeply indeed in their debt. At present, however, one cannot stifle suspicion that the phenomena described may have more to do with the enthu... | 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 | 只有“单向传播”是允许的:传播需要独立的感知和运动系统。(D
)绝对不应期之后会有一个相对不应期,需要比平时更强的刺激才能在这个阶段产生冲动,而且第二个冲动的电位变化或热效应要小于第一个冲动。放电可以在充电完成之前发生。(E
)由于存在不应期,所以冲动传播的重复频率是有限的。最近,纽约的盖瑟教授告诉我,他已经能让哺乳动物的神经在每秒内传递1,500个冲动,而且当达到每秒1,000个时,神经冲动并没有明显变弱。在功能正常的神经系统中,几乎所有的信息都是由一个个不同频率的神经冲动组成的。(F
)神经冲动在任意一个瞬间仅占据神经纤维中数厘米的范围。这个长度基本上不随温度的改变而改变,并与神经纤维的直径大致成正比。用简单的物理学原理一... | 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 | 如果事实真的如此,那么我们就不再需要寻找化学反应来解释初始热量了,电容放电已经足以说明一切。不过其他证据否认了电容放电是热量来源的观点。
英文
神经恢复到初始状态的复原过程是一种氧化过程,而去除氧气不会马上使其终止。显然,神经储存了大量非分子形式的氧,这也许是抵御窒息现象发生的一种手段。在它储备的氧耗尽之前,神经可以在数小时乃至数天内(取决于温度)继续发挥功能并且像往常一样进行复原。之后,也只有在氧气耗尽之后,神经才会失效。如果再次恢复对缺氧神经的氧气供应,它会很快复原并恢复活性。
英文
氧气的其他作用
蟹神经损伤部位和未损伤部位之间的电位差在有氧但没有刺激的环境下能够保持很长一段时间。刺激可以使之很快降低,这就是所谓的... | 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 | 生理学上的一个最重要的问题,同时也是一个具有普遍意义和哲学意味的问题,就是到底是什么决定了动物或细胞的时间尺度。
英文
在神经中,如果我们改变细胞存在的环境或者从一个细胞传入另一个细胞,则动作电流完成整个回路所需的时间、传播冲动所需的时间以及电兴奋的时间尺度(我将在后面提到)都会发生改变。这些都是同一现象——冲动传播的不同表现形式。上个世纪末,沃勒在利用电容器放电的刺激实验中发现,对于任何特定的组织都有一个“最佳”的刺激条件,此时电容内的能量最小。他以及他之后的基思·卢卡斯都发现:特定能量电容器的放电刺激效率依赖于电容器的放电速度。如果F
是电容器的容量,R
是放电时的电阻,则放电时间正比于FR
的乘积,因此对于给定的刺... | 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 | 但在持续时间很短时,电容器会首先充电,从而降低了跨介电质的有效电动势。如果在电容充分充电之前将加在上面的电流切断,其产生的电位差就会小于最终能达到的电位差,此时需要使用更大的电动势才能产生兴奋。
英文
根据这个模型,我们可以推导出如下的强度–时间曲线公式:
其中:C
是电流,t
是持续时间,R
是常数,F
是电容,r
是电极附近每平方厘米鞘的电阻,r
i
是两电极间神经的内部电阻,r
o
是两电极间神经外部液体的电阻。
英文
如果两个电极相距很远,(r
o
+r
i
)远大于r
,则上述公式可以近似表示为如下形式:
乘积Fr
对于决定这个关系式的形式起着重要的作用,它是电容与在每平方厘米纤维表面... | 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 | 这样一个直接建立在明确实验基础上的理论却因与事实完全不符而被取代,这在科学上是一桩怪事:但事实似乎就是如此。
英文
传播出去的扰动
我们已经讨论了电刺激产生兴奋的方式。尽管为了达到最有效的刺激,人们对各个方面都进行了调整,但所需的能量仍比神经自身在冲动传播时释放的能量大很多。就传播冲动而言,电刺激的耗费要远远大于点对点的自然刺激。这一点并不难理解。人工刺激的大部分能量都浪费在了神经纤维活性区域之外两电极之间的液体中。根据我们的假设,只有跨过表面阴极区的那部分电流才会形成有效的刺激。自然刺激在以波的形式传播时是点对点的,没有电极,也不会在不同液体中出现短路,因此刺激电流(如果传播是通过电流进行的)的利用效率是非常高的。
英文... | 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 | 如果兴奋的神经能够放出特征辐射,这种辐射可被用于鉴定在兴奋过程中发生的化学反应,那么人们就可以在新的起点上研究关于神经活性的物理本质这一非常困难的问题了。
英文
在卡伦达洛夫最近的一篇论文(《欧洲生理学杂志》,第231卷)中有一幅图,图中有若干张用石英摄谱仪分析得到、以酵母细胞为指示剂的连续光谱,其中(1)静息状态的神经,(2)破碎的神经,(3)机械刺激状态下,刺激点发出的辐射,(4)电刺激状态下,电极间的辐射,(5)损伤状态下,距损伤点20 mm处的辐射,(6)电刺激状态下,距刺激点20 mm处的辐射,(7)机械刺激状态下,距刺激点20 mm处的辐射。在图的下半部分是下列反应的图谱:(1)焦酚在空气中氧化,(2)糖酵解作用,... | 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 | A New Alloy, “Stainless-Invar”
K. Honda
Editor's Note
Precision-engineered mechanical devices such as watches rely on metal allows that will not expand significantly when warmed, which might otherwise cause jamming. Such low thermal expansion is rare, but was discovered in 1896 by Charles Edouard Guillaume in an allo... | 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 | coefficient of linear expansion at ordinary temperature of an alloy containing about 36.5 percent iron, 54.5 percent cobalt and 9 percent chromium is less than 10–7
in the annealed state, and that of another alloy having a very similar composition to the above has even a negative coefficient amounting to –1.2×10–6
. ... | 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 1932, German biochemist Max Bergmann and a colleague had devised a method for stringing together any two amino acids into a dipeptide—the benzylcarbonate method of peptide synthesis. Here, he outlines the steps of this reaction before describing how he is using it to study the subtleties of the peptide bonding. By r... | 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 | however, to regard the properties of a protein as a simple summation of those of its constituent amino-acids.
中文
The remarkable stability of the amino-acids is usually ascribed to their zwitterionic nature, from which results their capacity to form internal salts; the immediate neighbourhood of oppositely charged io... | 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 | -hydrogen atom, exhibit a definite mutual influence. A similar mutual influence but in the opposite sense is shown by the complete absence of racemisation when chloroacetylated amino-acids are treated with acetic anhydride under the same conditions. Such remote actions of different parts of the molecule upon one anothe... | 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 | According to the prevailing view, the biological degradation of an amino-acid to a keto-acid begins with a dehydrogenation, and conversely the biological synthesis of an amino-acid from a keto-acid ends with a hydrogenation. It is possible to combine examples of both these processes in a single experiment3
in vitro
. ... | 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 | derivative of ornithine5
.
中文
The latter result is of interest in relation to two physiological processes: (1) the creatine synthesis in vitro
shows how creatine-nitrogen can be derived from two different amino-acids; it is probable that in the course of metabolism creatine is formed in a similar manner from two 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 | Chemists have striven for more than thirty years to discover suitable methods for the synthesis of peptides containing the more complex amino-acids, but until recently only isolated successes have been obtained7
. Quite lately, however, a general method has been developed8
, the essential feature being the nature 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 | A complete picture of the possibilities of the new method of peptide synthesis cannot be given here, but it is possible to indicate some of the new lines of research which it opens up; in particular it may be of interest to mention certain hitherto unobtainable peptides which have been prepared by the benzylcarbonato 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 | Lysylglutamic acid on the other hand is attacked only with difficulty by dipeptidase; lysylglycine is readily hydrolysed by this enzyme and the same is true of the strongly basic lysylhistidine. These examples show that the preponderance of acidic or of basic groups does not interfere with dipeptidase action, since 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 | , 20 (1926); Bergmann, Kann and Miekeley, Liebigs Ann
., 449
, 137 (1926); Bergmann and Miekeley, Liebigs Ann
., 458
, 40 (1927).
Bergmann and Delis, Liebigs Ann
., 458
, 76 (1927); Bergmann and Stather, Z. physiol. Chem
., 152
, 190 (1926).
Bergmann and Köster, Z. physiol. Chem.
, 159
, 179 (1926); Bergmann ... | 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
因此,现代蛋白质化学的突出问题在于其两重性本质:肽键的形成对所参与的氨基酸施加何种影响?反过来,肽键自身的特性又是如何受到直接参与形成它的氨基酸的性质影响的?尽管人们对与该问题有关的这两个方向的研究尚处于起步阶段,但已经取得了不少进展,无论从化学角度还是从生物化学角度看,这些进展都非常重要。
英文
首先,我想通过一些例子来说明的是,如果我们通过对氨基进行简单的酰基化处理,使其转变成与它在多肽中相类似的状态,那么我们就能够揭示氨基酸的一系列新的化学性质。最简单的例子就是乙酰化反应,如果我们对一种具有旋光活性的氨基酸的氨基进行乙酰化处理的话,就会发现在常温下,只要与少量的乙酸酐接触,就足以催化乙酰化氨基酸发生快速的外消旋过... | 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 | 在此方面,几乎每一种氨基酸所受到的影响都是不同的。反之,每一种氨基酸对肽键的影响也肯定是相异的。
英文
为了能够利用有代表性的材料来研究这种影响,我们需要人工制备各种不同的多肽样品,并检验酶对这些多肽的作用是否存在差异。希望执行此任务并得到合乎逻辑的结论自然是极其困难的。然而,幸运的是,我们只需制备含有各种重要代表性类型氨基酸的多肽样品就够了。
英文
三十多年来,化学家们一直在努力寻找适当的方法来合成包含更为复杂氨基酸的多肽,但直到最近也只有少数几个案例是成功的[7]
。不过,就在不久前人们总算成功地建立了一种通用的方法[8]
,其关键之处在于用来封闭氨基的酸性残基的选择方面。
英文
苯甲基碳酸酰基氯可以很容易... | 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 | Amino-Acids, Proteins and Proteolytic Enzymes: II
M. Bergmann
Editor's Note
Following on from an earlier article that shed light on the complexities of the peptide bond, here Max Bergmann reflects on the action of proteolytic enzymes. His work made significant contributions to the study of enzyme specificity, buildin... | 400套付费套装书 |
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