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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 | sub-microscopic, but it can be seen at once from X-ray photographs that they are always effectively
long and thin and lie with their long axes either roughly parallel to the fibre axis, as in silk and hair, or arranged spirally round it, as in ramie and cotton.
中文
In the light of a mass of experimental evidence 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 | elasticity is inherent in the keratin molecule itself: by the application of tension in the presence of water the keratin molecule can be stretched to roughly twice its equilibrium length, to which it returns exactly when the tension is removed.
中文
More recent work on this problem indicates now that the “unit” of 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 | biological structures, and of which the elastic properties are of fundamental importance for our knowledge of the mechanism of both growth and movement.
中文
The paper presented by Dr. J. B. Speakman on the co-ordination of chemistry and X-ray analysis in fibre research followed admirably on the above account, emphasi... | 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 extended state. The reversibility of the intra-molecular transformation is thus destroyed by prolonged steaming, and the photograph of β
-keratin persists. The remarkable thing now is that it is found that de-aminated hair has lost this power of “permanent set”, and to an extent depending on the degree of de-amina... | 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 investigation is necessarily a prolonged one with the modest apparatus available, but already the findings are of a highly intriguing character. They show to date that the molecular structure of this cellulose balloon
is built up in spiral fashion, exactly as are the cellulose fibres
ramie, cotton, etc. The compl... | 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 biological implications of recent advances in the X-ray analysis of protein fibres were again dealt with by Mr. W. T. Astbury at the discussion on the structure of protoplasm. No doubt some of the zoologists present were not a little shocked at such heresy, but nevertheless the message of X-rays seems clear enough.... | 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 | 不过主要的障碍已经排除了,因为发现和解释了伸长
毛发的X射线照片,该照片显示,毛发角蛋白的分子或复合物在拉紧时发生了可逆的分子内转化,变成伸长的立体异构体,其中的多肽链具有与丝蛋白类似的形式,也就是说是完全展开的,相当于化学家所说的普通多肽链。由此可以知道,未拉伸毛发中的链处于折叠状态的平衡之中,因此具有非常高的弹性就成为角蛋白分子的固有特性:在有水存在时施加拉力,可以将角蛋白分子拉伸到约为其平衡长度的两倍,去掉拉力后分子又精确地回复到平衡长度。
英文
目前对这一问题的最新研究结果表明,角蛋白复合物的“单元”实际上是多肽层或“栅格”,其中主链通过一长列基本上共平面的交联并排地连在一起,这些交联结构是由包含在结构中的各种氨基酸... | 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 | 由于人们对法囊藻的代谢和结构都很感兴趣,所以大家在急切地等待着研究的完成。这种水藻的单个细胞是第一个用X射线方法进行精细研究的实例,研究结果表明它与纤维都具有螺旋形构造,这一发现对于生长机制问题必然会有深远的影响。
英文
生长机制还是泽尔利斯先生在一篇众所关注的文章中间接提到的主题,他展示了如何用X射线法说明构成牙釉质的磷灰石晶体的排布方式。像许多其他生物结构一样,牙釉质具有纤维的性质,磷灰石晶体中六方晶系的轴就是纤维轴。人类的牙釉质中有两组纤维,其中之一的纤维轴与牙表面的法线方向大约呈20o角并与顶部位于同侧,另一组则大约呈10o角且与顶部位于异侧。在狗的牙釉质中纤维轴与牙表面成直角。通过观测纤维取向的精确度就可以区分出三类... | 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 threshold value of which is 22,000 gauss at 2° K., a strength which is sufficient for many experiments.
中文
The chief remaining difficulty lies in the heat conductivity of the leads to the supra- conducting coil. This problem of heat conduction through the leads can be eliminated by transferring the necessary e... | 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 possible, with the above arrangement, to obtain temperatures below 0.1° K. from a starting point of 1° K. Since heat conductivity along the current leads is eliminated, and since heat capacities at helium temperatures are so minute, a few cubic centimetres of liquid helium should suffice to cool the whol... | 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;赵见高 审稿)
Natural Colouring Matters and Their Analogues
*
R. Robinson
Editor's Note
Robert Robinson, a professor at the University of Oxford, was the outstanding British chemist in the inter-war years. He was chiefly responsible for determining the structure of the colouring matter of flowers (with his wi... | 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 catalogue of outstanding achievements in this field invites destructive criticism. I do not fear this, however, in recalling the researches of Laurent, Kekulé, Baeyer and Heumann on indigo; of Sir William Perkin, Hofmann, Otto and Emil Fischer, Meldola and many others on the basic dyes; of Griess and his host of foll... | 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 this process a widely distributed anthoxanthin yields a widely distributed anthocyanidin, and the temptation to assume that similar reactions occur in the plant laboratory is very great. There is, however, very little justification for this view, and the experimental support brought forward in its favour will not su... | 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 | ) we find callistephin, the monoglycoside of pelargonidin occurring as one of the pigments of the aster and as the main pigment of scarlet carnations and many other flowers; the related galactoside, fragarin, is the colouring matter of the strawberry.
中文
In the cyanidin series the corresponding pair is chrysanthemin... | 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 derived from the same anthocyanidin, exhibit similar behaviour as indicators. Thus chrysanthemin, keracyanin and mecocyanin all give a violet solution in aqueous soda and this becomes blue on the addition of caustic alkali. On partial hydrolysis, mecocyanin and antirrhinin actually yield chrysanthemin.
中文
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 | -hydroxycinnamic acid, probably attached to the sugar hydroxyls, and pelargonin and cyanin also occur in acylated forms. These so-called complex anthocyanins are characterised by high distribution numbers; they are usually acylated 3:5-dimonosides, but in the delphinidin series, gentianin and violanin appear to be 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 | Now cyanin was isolated by Willstätter and his colleagues from the blue cornflower and from the red rose, and it seemed quite a simple step to assume that the cell-sap in the cornflower was alkaline and that in the rose acid, particularly in view of the fact that the absorption spectra of the coloured aqueous extracts ... | 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 form of colloidal solution was considered most likely to fulfil the necessary conditions, and Dr. Conmar Robinson, of the Chemistry Department, University College, London, kindly examined a filtered, distilled water extract of blue cornflowers and reported as follows:
“The solution contains ultramicrons easily vis... | 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 | attempted to produce blue acid cyanin solutions in the presence of various polysaccharides. The addition of dispersed xylan and various kinds of starch, also agar-agar, makes the preparation of blue solutions of p
H about 7.5 a very simple matter, but we have not yet found a way of imitating the cornflower solution 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 | H 5.0); flower, pelargonidin 3-bioside (p
H 4.5). On the other hand, three scabious with anthocyanins based respectively on pelargonidin, cyanidin and delphinidin had all the same petal p
H, 5.0.
中文
We have already discussed elsewhere the influence of certain substances termed co-pigments on the colour of anthocya... | 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 justification for assuming the operation of this factor can best be indicated by an example. Certain herbaceous phlox contain pelargonin, but have a much bluer-red colour than other flowers coloured by this anthocyanin. But the same observation applies to the extract in 1 percent hydrochloric acid, and moreover 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 | 因此,可以从蓝色矢车菊、红玫瑰、深红色大丽花和其他一些花中分离得到的紫色颜料矢车菊色素苷能够形成一种蓝色的钠盐和一种红色的盐酸盐。后者在热的盐酸溶液中水解成氯化矢车菊色素和葡萄糖,用化学方程式表示如下:
通过分析和大量的合成已经确定了氯化矢车菊色素的结构;最早的方法由维尔施泰特和马利松创立,是在甲醇–盐酸水溶液中用镁还原槲皮苷。
英文
在这一过程中,广泛分布的花黄素生成了广泛分布的花青素,这极大地诱惑人们去设想类似的反应可以发生在植物实验室中。不过,几乎没有什么证据可以支持上述观点,对其有利的实验证据经不住仔细的推敲。所谓通过还原天然黄酮或含黄酮的植物提取物而制备出的结晶花青素只不过是吸附了少量花青素类染色物质的上述黄酮。看... | 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
花青素系列中的全体成员都是花青苷的酰基化物;例如,来自飞燕草中的色素——飞燕草色素苷在水解时会产生对羟基苯甲酸、葡萄糖和飞燕草色素。
英文
很多其他的飞燕草色素衍生物也是通过对羟基肉桂酸酰基化得到的,酰基基团可能连接在糖羟基上,而且花葵苷和矢车菊色素苷也能以酰基化形式出现。这些所谓的复合花青苷以高分配系数为特征,它们通常是3,5–二单糖苷酰基化物。但是在飞燕草色素系列中,龙胆晶苷和堇菜苷似乎分别是单葡萄糖飞燕草苷和鼠李葡萄糖飞燕草苷的对羟基肉桂酸酯(卡勒)。还有某些证据表明存在另一种缩酚酸类型的花青苷,其中酰基基团直接连在花青素分子上,而葡萄糖苷基则连接在酸残基的羟基之上。
英文
作为指示剂的花青苷和花的颜色
... | 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
可能pH值在5.5和6.5之间时,形成上述缔合胶体要容易得多。总的来说,蓝花所含的酸性细胞液要少于红花。玫瑰花瓣与矢车菊形成对比,构成了一个特例(pH 5.6)。
英文
必须要强调的是,pH值的变化本身远不足以解释颜色的变化,虽然决定花色的最重要的单一因素,即赋予花青苷本质特征的因素,是溶液中色素的存在条件,可能所有蓝色花朵的颜色都来自于各自所含色素的胶体溶液
。
英文
测定花朵细胞液中氢离子浓度的方法取决于所用指示剂的花的颜色,这种说法可能是合理的,但必须有这样一个前提,即要保证色素溶液的胶体状态不会因提取时所用的缓冲溶液而改变。无论如何,这些结果与在体外观测被分离出来的花青苷所看到的颜色没有关系,并且一朵花... | 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 | star's rotation. That would make its presence consistent with the temperatures (up to 10-20 million degrees) that astronomers had estimated.
中文
T
HE letter of Gamow and Landau1
suggests that an upper limit to the internal temperature of a star can be obtained by considering the disintegration of lithium. Investiga... | 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 volume of the star.
中文
The existence of these circulating currents will raise the upper limits given by Gamow and Landau. Since the disintegration is sensitive to changes of temperature, the increase may not be very large; but it may well be sufficient to remove any difficulty in accepting the temperatures of 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 | This review of the understanding of free radicals in chemistry, based on a discussion meeting in Cambridge, shows how sophisticated mechanistic organic chemistry had become by the 1930s. Free radicals are chemical entities (atoms or molecules) that have “unpaired” electrons, occupying an electron orbital by themselves.... | 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 opening paper, Prof. Lowry laid stress on the significance of free radicals for theories of valency and of the mechanism of organic reactions. In terms of the electronic theory, the splitting of a covalent link may be thought of as taking place unsymmetrically, giving two ions of opposite sign, or the link may 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 | It is convenient here to mention a remarkable result obtained by Norrish for higher ketones. With methyl butyl ketone the products of photochemical decomposition are acetone and propylene.
Since the radiation used is that absorbed by the carbonyl group, this reaction presents an interesting problem in molecular mechan... | 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 | ethane linkage.
中文
中文
The number of radicals of the triphenyl methyl type now known is very large and progress is to be expected rather in the accurate physico-chemical study of known complexes than in the preparation of new substances. Ziegler and his co-workers have already developed accurate methods for determ... | 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 | activation of the hexaphenyl ethane molecule. Hückel terms the energy of stabilisation the “static bond strain”, and computes its value approximately for typical substituted ethanes. With six aromatic substituents the static bond strain is 55 Cal., in fair agreement with Ziegler's experimental results. The strain decre... | 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 number of papers were contributed on the chemical reactions of radicals of short life. The simplest of all free radicals is, of course, atomic hydrogen, which can be produced in high concentrations by a discharge through hydrogen at pressures of less than 1 mm. This radical has the comparatively long life of about 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 | Finally, a number of papers were devoted to the study of free radicals in electric discharges by spectroscopic or positive ray methods. Of these there is only space to mention the important report by Mecke on “Free Radicals and Spectroscopy”. Spectroscopic methods not only detect the presence of free radicals but 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 | 对偶极矩的测定显示,单个共价键可以表现出一定程度的极性,但极性的大小远远小于电子从一个原子转移到另一个原子所形成的偶极矩的大小,在晶体结构和拉曼光谱方面积累的数据也说明离子键和共价键在实验中存在差异。
英文
因此,考虑有机反应时必须考虑两种主要的反应机制。拉普沃思曾指出氰醇的形成过程实质上是一个离子反应,因而,劳里用一个双键的瞬态极化阐述了这一过程。
另一方面,烃的热分解和许多光化学变化都不能以离子反应的形式表达。诺里什发现甲乙酮的光化学分解过程可以表示如下:
最终产物是一氧化碳和等量的乙烷、丙烷和丁烷的混合物,混合物中三种成分的含量几乎相等。显然,这些产物很容易用甲基自由基中间体和乙基自由基中间体的形成来进行解释。
... | 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
许多投稿的文章都是关于短寿命的自由基的化学反应的。在所有的自由基中最简单的自然是氢原子。当压强小于1毫米汞柱时,氢气在放电条件下可以产生高浓度的氢原子。这种自由基有着相对较长的寿命,大约是1秒。哈特克描述了最近的一些对氢原子和氧原子自由基的化学性质的研究。他在低温下(液态空气或氢气)得到了一些非常惊人的结果。氢原子与氧反应可以生成大量的过氧化氢,与汞反应可以生成含有70%氢化汞的固体产物,与乙烯反应可以生成乙烷。当压强为1个大气压时,后一个反应在15分钟内可以生成500毫升的乙烷。
英文
潘内特描述了用游离的甲基和乙基来合成金属有机化合物的方法。经过长期的寻找,在分离出的化合物中得到了类似于二甲砷基的锑化物(CH3
... | 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 put forward the view “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 deserts, by the heat so developed”.
中文
The radioactivity of eight specimens of tektites and of some pieces ... | 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 radioactivity of Darwin glass differs from all other tektites considerably and agrees more with glass than with tektites. In this connexion the similarity of silica glass from Wabar and Henbury to the Darwin glass as observed by Dr. Spencer is noteworthy.
中文
The value 1.00×10-12
per gm. found for the tektites 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 | 英文
来自世界上相隔很远的地区——欧洲、亚洲和澳洲的玻陨石均具有相同的放射性含量,这显然说明它们在起源上具有一定的相关性。很难想象,在三个不同的大陆中由不同原岩形成的玻陨石会具有相同的镭含量。
英文
我们测定了几种玻璃状物质中的放射性含量,包括史前时代的玻璃珠,然而测得的值都比较低,相互之间的差别也很大,最大值高达每克0.48×10-12
。这些玻陨石中的放射性组分绝对不可能来自于铁陨石,因为铁陨石的镭含量很低,量级在10-14
左右。
英文
达尔文玻璃的放射性与所有其他玻陨石的差别非常大,倒是与玻璃更为相似。关于这一点,斯宾塞博士发现瓦巴地区和亨伯里地区的硅质玻璃与达尔文玻璃的相似性值得注意。
英文
玻陨石... | 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 | Spencer's suggestion finds support in the presence of metallic spheres, resembling those of the Wabar glass, in Darwin glass and in tektites from Indo-China, as described in his letter; and also in the presence of nickel in three Malayan tektites, proved by analyses by Mr. J. C. Shenton. As Dr. Spencer remarks, the evi... | 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 recent years I have endeavoured to explore the decay of the intensity of cosmic radiation over as wide a range as possible after its entrance into the earth's atmosphere. I believe that such an investigation is indispensable before a theory of the nature of cosmic radiation can be put forward. In Nature
1
and in 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 | We have also employed another form of balloon electrometer. Our balloon electrometers hitherto constructed each had the ionisation chamber filled with air at a pressure of three or four to five atmospheres. The new electrometer has an open
ionisation chamber, that is to say, a chamber communicating with the air outsid... | 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 | due to the inaccuracy of the measurements. It can be seen that the middle parts of the fourth curve agree very well with the others. Moreover the fourth registration, of March 29, 1933, is the best of all with the closed electrometers. It was also possible to obtain observations during the descent of the balloon (Fig. ... | 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 | sunspot. But up to now we have observed this but once. Further observations are necessary in order to ascertain whether this is real.
中文
From the measurements of the decay of the intensity of the cosmic radiation in Lake Constance, my collaborator, Dr. W. Kramer3
, has deduced that there are many components 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 | . The curve for rays entering the atmosphere vertically shows that their intensity diminishes towards the top of the atmosphere. Thus it agrees with the suggestion that at least a part of the radiation is electromagnetic. There is also a second maximum produced by the second component of the soft part of the radiation.... | 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 curve, because the pressure is in proportion to the mass of the layer which is penetrated by the rays.
中文
The two measurements made with such an ionisation chamber do not quite satisfy us yet. The first chamber employed was too small (volume only 22 litres) and therefore the sensitivity was inadequate. 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 | E. Regener: Technical High School, Stuttgart.
References:
Regener, E., Nature
, 130
, 364 (1932).
Regener, E., Phys. Z
., 34
, 306 (1933).
Kramer, W., Z. Phys
., 85
, 411 (1933).
Gross, B., Z. Phys
., 83
, 214 (1933).
Lenz, E., Z. Phys
., 83
, 194 (1933).
*
Paper before Section A (Mathematical and Physica... | 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 | 那是因为“玻璃房”效应,静电计的周围被像温室的玻璃一样包裹着,使它能够抵御平流层的寒冷。
英文
我们相信,第四次实验得到的曲线与前三次结果之间的差别是真实的,而且我们曾试过做出解释。我们在四次实验所处的环境中寻找原因。在第四次实验时,出现了一轮新月,我们认为,月面的放射性或许是造成那天强度更大的原因,因为在其他几次实验中,天上没有出现月亮。顺便说一下,我们应该知道,当气压低到20或30毫米汞柱时,一般的放射性物体发射的γ
射线就已经有三分之一能够透过大气了。但在经过了简单的计算之后,我们发现月亮的辐射不可能造成这么大的影响,所以这个解释是不正确的。接着,我们又查询了这四天里磁场扰动的情况。德国波茨坦的尼波德教授和瑞典北部的科... | 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
图2.
英文
一般而言,如果我们想得到一条从海平面到大气层顶部的完整曲线,用开放电离室进行测量是很方便的,因为开放电离室的观测值只在1到5之间变化,而封闭电离室的测量值则会从1一直变化到150。因此,在图2中,开放电离室的标准强度曲线在较低部分会比密闭电离室的更精确,密闭电离室标准曲线上的值是由开放电离室的值乘以p
0
/p
得到的。
英文
我要感谢奥尔先生在测量中给我的帮助,以及“德国科学临时学会”对这项研究工作的支持。
英文
(刘霞 翻译;马宇蒨 审稿)
*
这篇论文曾在英国科学促进会A分会(数学和物理学分会)于9月8日在莱斯特举行的会议上被宣读过。
Interaction of Hard ... | 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 | -ray source was a radiumthorium preparation equivalent to 10 mgm. of radium. Two Geiger-Müller counters, one having an aluminium wall and the other a lead wall, were used. The counters had equal inner dimensions and approximately equal mass per square cm. of the wall (that is, 0.92 mm. thick for the aluminium counter 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 | -rays. If this were the case, the difference of the ratios for γ
= 6.6 x.u. and 4.7 x.u. should be more pronounced by using counters of thicker walls, since the effect of scattering increases with thickness of the wall. But the same result, namely, a difference of about 16 percent between the two ratios, was obtained ... | 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
众所周知,当一束由钍C′′放射出的硬γ
射线穿过铅时,除了出现铅的外层电子对γ
射线的吸收以外,还会出现铅原子核对γ
射线的吸收,并伴随着发出和初级辐射具有不同频率的特征辐射[1]
。这种特征辐射的强度已经被估算过了,即放射出的特征辐射的总能量远远小于被原子核吸收的初级辐射的总能量[2]
。我们可以预见,如果假设原子核在这一过程中发生了衰变,那么原子核吸收的一部分能量就会在此过程中被消耗掉。从这种观点出发,我们测量了由初级γ
粒子从铅原子核中打出来的电子。
英文
我们在实验中采用的γ
射线源是镭–钍合成的放射源,相当于10毫克的镭放射源。所使用的两个盖革–缪勒计数器,一个是铝壁,另一个是铅壁。两个计数器具... | 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 | Radioactive beta decay had proven most baffling. Unlike alpha particles, beta particles were emitted not with a well-defined energy, but with a broad range of energies, and physicists had established that these energies were created in the nuclear process itself, not as the electron interacted with shell electrons. Her... | 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 with the nuclei of elements. These experiments have been interpreted by Blackett and Occhialini as indicating the conversion of a γ
-ray quantum into an electron and a positron near the nucleus. Curie and Joliot have brought further evidence in favour of this view by showing that γ
-rays of thorium C′′ (energy ... | 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 | “electro-division of the quantum”.
中文
Let us see how we can explain β
-ray activity. If the “electro-division of a quantum” can be brought about by a nucleus when the quantum hits it from the outside, it is much more probable that the γ
-rays produced within the nucleus itself should be completely split up into an... | 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 | -ray disintegration is emitted. The life-period is therefore determined by the time of leakage of an α
-particle or proton from one barrier to another, and this explains why the life-periods of β
-ray bodies are of the same order as those of α
-ray bodies, and have a definite value.
中文
(132
, 747; 1933)
M. N. Sa... | 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 | γ
射线可以在原子核中的任意位置发生“内部电分离”,这样,γ
射线转化产生的电子的速度就会在很宽的范围内变化。只有得到更多的实验数据,我们才能进行严格的数学计算。和中子结合的正电子将产生软γ
射线,这种软γ
射线经常出现在β
衰变反应中。
英文
根据上面的观点,β
射线的发射只是一个二级过程,初级γ
射线的产生才是引发这个反应链的最初原因。现在我们可以问问自己:这种γ
射线是如何产生的呢?一定是因为一个α
粒子或者一个质子从一个势垒穿越到另一个势垒而产生的。伽莫夫以及康登和格尼曾经以放射性原子核中只存在一个势垒出发解释了具有确定速度的α
射线的放射,但是一些争论表明,原子核中可能会有不止一个势垒。在一个α
... | 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 appears that these phenomena of stability and inherited change can only be understood by recognising that some substances or structures in the chromosomes must maintain in general their spatial relationships and chemical nature, not only from one generation of organisms to another, but also with only minor changes 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 | In what sense do genes exist? The gene is probably the last in the long series of representative particles beginning with Darwin's “gemmules” and the “pangens” of de Vries, which were formulated to account for the phenomena of heredity. With advancing knowledge, such conceptions have tended to lose their formal charact... | 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 have been two main theories of chromosome structure. According to one theory, the core of the chromosome contains a continuous thread or chromonema, which takes on a spiral form in various stages of mitosis. Cytologists have brought strong evidence for the existence of chromonemata in plant cells. The investigati... | 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 | is the case, it would appear that whole families or even villages of genes must live in one house. Belling (1928) endeavoured to count the number of chromomeres in certain plant nuclei and has arrived at 1,400-2,500.
中文
In a posthumous paper recently published, as well as in earlier papers, Dr. Belling strongly supp... | 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 within the visible chromosome, it is well to emphasise this point.
中文
The absolute discreteness of the genes within the chromonemata does not appear to be an essential part of the gene theory. It is well known that many of the Protozoa have numerous chromosomes which undergo longitudinal fission and exhibit 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 | their individual chromosomes are internally homogeneous, each containing a different type of genic material.
中文
The current view of genes, as developed particularly in connexion with Drosophila
, tacitly assumes that all genes are of the same kind. If the views here expressed have any validity, then it seems more 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 | , the number of loci in the nucleus being estimated at more than 14,000. This maximum size would only allow space for about fifteen protein molecules. There is at present a large margin of error in such estimates. From measurements of spermheads and chromosome lengths, these authors draw the interesting conclusion that... | 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 | forces alone could scarcely be expected to hold such a chain together, even if we rely upon the properties of the carbon atom. On the other hand, whatever physical forces give the chromosome its unity as a structure, might also be concerned (1) in organising each group of like or unlike molecules into a gene, and (2) i... | 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 | , Demerec on Delphinium
and Drosophila
are notable in this connexion. Eyster (1928) adopts the hypothesis that the genes causing variegation are compound structures composed of a constant number of “genomeres” which may or may not be of the same chemical or physical nature. Demerec (1931), however, explains the varie... | 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 | 然而,这种变化导致的结果却是可遗传的,这表明,生物体没有能力对其细胞结构中这一特殊部分的变化进行调节。
英文
遗传的稳定性和可遗传的变异这两种现象似乎只能这样来解释:染色体中的一些物质或者结构不仅会在生物体从一代传给下一代的时候大体保持原有的空间关系和化学性质,而且在跨越千年,甚至有时候可达几百万年的过程中,都只发生微小的变化。不管原生质如何生长,遗传物质都必须以保持自身物种永远不变的方式自我复制,因为当遗传物质发生变化时物种也就发生了变化。
英文
上述结论似乎是现代遗传学研究必然得到的结果,然而在强调这些结论的同时,我并不想忽略细胞质的重要性。有例子显示,胚胎学家们(例如:康克林和利利)通过研究发现,在各种动物的卵中那... | 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 | 他不但否定了染色体在有丝分裂的末期分离,而且还提出了新的观点,即认为在有丝分裂的前期,连接染色粒的细丝并不随着染色粒的分离而分离。相反,他认为这些粘连的细丝在新生的子染色粒间重新形成,进而把它们组合成一条新的染色体。这种观点的主要优点在于它能消除存在于所有有关染色体交叉和交换的现存理论中的许多严重困扰。事实上,一些有水平的细胞学家们也可以持有不同的观点,这表明在该领域里得到关键的观察结果是极其困难的。
英文
本试验室在近期的观察中得到的最新资料表明,染色粒也许并不存在,至少在植物细胞中是这样的。我们发现至少在某些时候,经过精密的分析,一串珠子或一条念珠形的线其实是由两条染色丝螺旋缠绕形成的,这些染色体丝上的节点和节间段在表现上... | 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 | 大部分染色体很可能都是由胸腺核酸组成的,但镶嵌在染色丝轴上的基因并不一定是该物质的衍生物。
英文
尽管贝林认为每个染色粒都含有一个可见的基因,但是大量的事实说明基因是普通显微镜无法看到的,最近布里奇斯(1932年)提出了基因是单分子物质的观点。人们通常把基因看作是有确定结构的实体,由二十个或几百个分子组成,通过有机性的分裂或者化学上的复制实现自身的繁殖。把基因看作是一个单分子虽然排除了它的可分割性,但似乎又增加了另一个麻烦。很难想象如果不是分子,一条脆弱的单链能稳定地保持在染色体的核心上,因而我们必需这样假设。仅靠化学力几乎不可能将这样的链结合在一起,即使我们信赖碳原子的特性。另一方面,如果使得染色体具有统一结构的是物理作用力... | 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 a voyage from Holland to South Africa, which also showed a clear minimum near the equator. Unfortunately, he says, his apparatus had broken down, and he could not gather data from southern latitudes, which might have helped clarify an apparent difference noted by other researchers between the flux in the two hem... | 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 | seem that an accurate repetition of this kind of measurement to obtain the exact shape of the curve is not superfluous.
中文
Regarding my observations, the following particulars may be given. The ionisation chamber had a volume of 3 litres and contained argon at a pressure of 30 atm. It was shielded by 8 cm. of iron 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 | Clay, J., and Berlage, H. P., Naturwiss
., 20
, 687 (1932); Clay, J., Naturwiss
., 21
, 43 (1933).
Hoerlin, H., Nature
, 132
, 61 (July 8, 1933).
宇宙射线的纬度效应
约翰·普林斯
编者按
雅各布·克莱、阿瑟·康普顿和其他人的早期实验曾经说明宇宙射线的通量在靠近赤道处有一个最小值。本文中,普林斯报告了他在从荷兰开往南非的斯普林方廷号远洋轮上利用装载于船上的电离室测量得到的结果,该结果同样说明在赤道附近会出现一个最小值。他说,不幸的是他的仪器坏了,所以没有能够收集到南纬的数... | 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 dispute the idea. Here Theodore Eugene Sterne of Harvard College Observatory weighs in, saying that Eddington's objection invokes conditions under which stars would be unstable, but that lithium might actually be formed as well as destroyed en route to the stellar surface, if temperatures were even higher than Eddin... | 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 | , unless there is a delay of the order of months or years between an increase in T
and the resulting change in ε
. The most important contribution to the total energy liberated by transmutations comes from the disappearance of hydrogen because of its large packing fraction, and the rate at which the speed of disappea... | 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 well as disintegrated, and by the aid of ascending currents some of it could perhaps appear on the surface. Since it would not be subjected to disintegration alone
throughout the trip to the surface, for a time the abundance might even increase. If elements are being made as well as being disintegrated, the difficu... | 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 | 西奥多·尤金·斯特恩
编者按
苏联的乔治·伽莫夫和列夫·朗道最近提出:从天文观测推断恒星的内部温度高达几千万度,这与恒星表面存在锂元素的事实相矛盾,因为锂在恒星内部会与氢发生核反应从而被消耗掉。阿瑟·爱丁顿在《自然》杂志上撰文反对这个观点。在这里,哈佛大学天文台的西奥多·尤金·斯特恩也加入了讨论,他说爱丁顿的反对意见是以恒星处于不稳态为条件的,不过当温度高于爱丁顿所设想的温度时,也许可以认为锂在向恒星表面扩散的途中,损耗和生成的过程在同步进行着。
英文
伽莫夫和朗道[1]
认为,或者质量数为7的锂元素只能偶尔在恒星表面存在,或者恒星内部根本不存在温度超过几百万度的区域。他们的理由是当温度更高时,锂在衰变之前恐怕无法从“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
(魏韧 翻译;邓祖淦 审稿)
Oxygen Affinity of Muscle Haemoglobin
R. Hill
Editor's Note
That the red colouring matter in muscle and blood is similar but not identical is borne out by this paper, with its evidence that the absorption of light differs between the two tissues. It had been suggested already that “muscle haemoglo... | 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 means of a rapid spectroscopic method of measuring dissociation curves, the oxygen affinity of muscle haemoglobin has been compared with that of the haemoglobin of blood in a borate buffer at p
H 9.3 and 17°C. The method consists in introducing different amounts of a dilute (10-4
m.) haemoglobin solution into an e... | 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 seems clear that the presence of muscle haemoglobin within the muscle cells will be of definite advantage in oxygen transport. The actual amount of haemoglobin in the heart muscle is of the same order as the amount of haemoglobin in the capillaries. The dissociation curve is decidedly less inflected than that 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 | 根据克罗格方法的原理,通过与氧合血红蛋白和无氧血红蛋白的光学混合物进行比较,我们可以估算出氧合血红蛋白所占的百分比,继而我们可以计算出容器中的氧分压。对于溶解在pH值为9.0、温度为18°C的硼酸盐缓冲液中的哺乳动物血红蛋白而言,其溶液和容器中溶液上空的体积处于同一量级,因此氧气在二者之间的平衡能很快就被建立。当涉及血红蛋白有可能转变成高铁血红蛋白的条件时——这对肌肉中的血红蛋白而言是显然会发生的——这样一种快速检测方法就成为非常必要的了。
英文
图1展示了两条解离曲线,其中一条(右边的)代表的是牛血液中的血红蛋白,另一条(左边的)代表的是从在pH值为9.3、温度为17 °C时灌注的牛心脏的肌肉中提取的血红蛋白。
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 | transformation. The production of positive electrons in the laboratory is therefore an easy matter.
中文
The charge and mass of a positive electron can be calculated from the ionisation it produces. For example, Anderson2
has estimated that the difference between the ionisation due to fast positive and negative elect... | 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 some unpublished results of Chadwick, Blackett and Occhialini, gives the numbers of positive electrons ejected in a forward direction from different elements by various radiations, the numbers being expressed as a fraction of the observed number of negative electrons. These percentages give only a rough indicatio... | 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 | ) Since there is certainly no room, in atomic theory, for the permanent existence of positive electrons well outside a nucleus, then a positive electron that comes from there must be born there, and if born there, an equal negative electron must be born simultaneously in order to conserve electric charge. This is confi... | 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 necessary consequence of the occurrence of the process whereby a quantum interacts with an atom to produce a pair of electrons of opposite sign, is the occurrence of the reverse process, in which a positive electron and a negative electron interact with each other and the field of an atom to produce a single quantu... | 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 | On this view, only an unoccupied state or “hole” would correspond to an observed particle. It followed from the theory that such unoccupied states should behave in an external field like particles with the same mass and spin as a negative electron but with a positive charge. The experimental discovery of the positive e... | 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 so that both disappear with the emission of two quanta of half a million volts energy.
†
It is remarkable that the re-emitted radiation is estimated by Gray and Tarrant to be composed mainly of just these two energies, of one half and one million volts. However, Fermi and Uhlenbeck9
have found that... | 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 greater energy of the positives may be explained by the fact that a positive electron gains kinetic energy and a negative electron loses it, on escaping from the field of a nucleus. This resulting difference in kinetic energy will be the larger the nearer to the nucleus that the pair is born, and so should be large... | 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 appears that the positive electron, though rare, because ephemeral, on earth, is an important constituent of the universe as a whole.
中文
(132
, 917-919; 1933)
References:
Anderson, Science
, 76
, 238 (1932). Blackett and Occhialini, Proc. Roy. Soc
., A. 139
, 699 (1933).
Anderson, Phys. Rev
., 43
, 491... | 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. in water, the life being inversely proportional to the density. If this predicted process is verified experimentally, it will be possible to assume the reverse process, the creation of a pair of electrons of opposite sign by the collision of two quanta of high energy. This latter process would then be the first ca... | 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
吸收了辐射能量为5.0×106
伏特和2.62×106
伏特的正电子,其最大能量分别约为4×106
伏特和1.6×106
伏特,也就是说,在各种情况下,正电子的能量都要比量子能量大约少100万伏特。
英文
如果正电子确实是在原子核外产生的,那么就有以下几个重要结论:
(a
)根据原子理论,既然肯定没有正电子在原子核外长期存在的余地,那么来自那里的正电子必然是在那里产生的,而如果那里产生了正电子,考虑到电荷守恒,那里也必将同时产生一个带有相同电量的负电子。实验上确实观测到了成对的粒子轨迹,这显然可以解释成同时发射出正负电子对,实验有力地证明了以上的结论。
要产生这样一对正负电子需要消耗的能量为(m
1
+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 | 但是,费米和乌伦贝克[9]
发现,理论上硬成分的辐射能量的强度要远远小于实验上的观测值。
英文
我们可以把原子吸收硬γ
射线从而产生带有相反电荷的电子对的过程看作是一个通过“虚”电子来实现的光电吸收过程,这个“虚”电子即原子核附近具有负动能的电子。根据贝克[10]
的理论研究,我们可以认为这些虚电子具有2mc
2
量级的结合能。贝克还表示,吸收过程中的有效虚电子数和原子序数的平方成正比,并且每个铅原子中大约有一个虚电子。理论结果还显示,电子对的产生过程发生在与原子核的距离小于h
/2πmc
= 3.85×10-11
cm的范围内,这个范围恰好在K
壳层之内。
英文
居里和约里奥[11]
发现,当铝
和... | 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 | diffusion and the activity of living organisms. As a projectile for studying nuclear processes, the heavy hydrogen nucleus had already been used to induce elemental transmutation. Rutherford favours the name “diplogen” for heavy hydrogen and “diplon” for its nucleus, over the American proposal of “deuton”. The isotope ... | 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 | was found to be 1.79 A. greater than for H1
—a result agreeing closely with the theoretical value to be expected for an isotope of hydrogen of mass 2. The mass of the new isotope was directly measured by Bainbridge, using a modified type of mass-spectrograph, and found to be 2.0136, slightly less than the weight of 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 | ions that a group of protons of nearly the same speed was released from a number of elements. In explanation, he suggested that the H2
nucleus broke up into a neutron and proton either in the bombarded nucleus or in the strong field in its neighbourhood. For the conservation of energy to hold, it is necessary to suppo... | 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 | was rapidly enriched in the residues after electrolysis. This general method was first used on a large scale by Lewis and Macdonald of the University of California in order to obtain a concentrated preparation of heavy water. By this method they have obtained quantities of heavy water of the order of several hundred cu... | 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 | , while the compounds formed with the new isotope are to be expected in some cases to exhibit rather different properties from the normal hydrogen compounds. Similarly, this new discovery opens up interesting questions on the effect of heavy water in altering the normal physical and chemical processes in animal and pla... | 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 and a neutron. We estimate that the maximum energy of the ejected neutron may be as great as fifteen million volts. We have confirmed this conclusion by finding that neutrons can be detected in numbers corresponding to this mode of transformation using H2
particles of energy about 200,000 volts. Lauritsen 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 | nucleus, not only as a projectile for atomic transmutations, but as a possible constituent of atomic nuclei. Lewis has suggested the name “deuton” or “deuteron” for this nucleus. While we all realise that the first discoverer has a strong claim in suggesting an appropriate name for a new substance, the question of a su... | 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 | 他们在实验中成功地找到了极少量的H2
,最初估计H2
的含量约为H1
同位素的1/4,000。H2
α
线的波长比H1
的相应波长长1.79 Å——如果认为氢具有质量数为2的同位素,根据理论计算出的结果与此非常一致。班布里奇采用一种改良的质谱仪直接测得这种新同位素的质量为2.0136(在O=16的前提下),略低于普通氢分子的重量2.0156。
英文
我们没有明确的证据证明H2
的具体构成,无法确定应把它看作是一个简单的实体还是由两种或多种成分构成的。起初人们很自然地想到H2
核可能是由两个质子和一个负电子组成的,但在发现了中子之后人们更倾向于把它看作是一个中子和一个质子的紧密结合体。如果认为中子的质量等于查德威克... | 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 | 迪伊和瓦耳顿利用威尔逊云室拍摄了α
粒子的轨迹,由此证明这种说法是完全正确的。
英文
用H2
作用于质量数为7的锂同位素将会得到更为复杂的结果,奥利芬特和我观察到其释放出的α
粒子有很宽的速度范围。这种情况似乎说明质量数为7的锂核在俘获了H2
之后分裂成两个α
粒子和一个中子。我们估计被发射出来的中子所具有的最大能量可以达到1,500万伏特。我们已经通过以下方式证实了这一结论,即当用能量约为200,000伏特的H2
粒子时,我们检测到了大量按照这种转化模式嬗变的中子。劳里森发现用H2
粒子轰击铍可以得到数量众多的中子,而劳伦斯虽然也用极快的H2
粒子从锂中得到了很多中子,但他倾向于相信在他实验中观测到的大部分中... | 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 a series of observations, Vinson and Petre1
claim that the virus disease of tobacco mosaic behaves as a chemical compound. We have repeated this work in detail and confirmed it in every particular, and we are also of the opinion that the virus in this case behaves as a chemical compound and not as a living organism.... | 400套付费套装书 |
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