摘要:

AbstractIf a long chain molecule in a solution carries electric charges, the statistical coil is inflated, and the average square of the distance between the ends of the chain is larger than in the uncharged state. For a number of properties the determining factor is the value of ∑k(r2k)av, where rkis the distance between the k'th link in the molecule and the centre of gravity. This quantity is proportional to the square of the effective radius and is related to the square of the distance between the ends by a simple formula (section 2), provided the radius of the coil is small compared with the length of the extended chain.In section 3 the electrical free energy of the molecule is derived as a function of effective radius on the assumption that no electrolytes are present. This free energy determines in its turn the average dimensions of the coil.In section 4 a similar theory is developed for charged polymer molecules in the presence of electrolytes. The change of the effective radius with the charge on the polymer and the concentration of the electrolytes is calculated. In the limit of high electrolyte content the equilibrium between the interior and the exterior of the polymer coil may be considered as aDonnanequilibriu

ISSN:0165-0513    

DOI:10.1002/recl.19480671002

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractX‐ray analysis of the crystals of gammexane, 1,2,3,4,5,6‐hexachloro‐cyclohexane, proves this isomer to be of the p,p,p,e,e,e

ISSN:0165-0513    

DOI:10.1002/recl.19480671003

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractSpectrophotometric determinations of the percentage of oxyhaemoglobin in blood are described in the literature.In applying this method we encountered some difficulties especially in relation to sampling. In this communication we intend to give a summary of our experience with this method.1The following factors were examined:a)the most favourable wave lengths for measuring the maximal cq minimal absorption of oxyhaemoglobin and haemoglobin,b)the influence of saponin (used for haemolysation) on the extinctions,c)reproducibility of the quotients of the extinctions (E1and E2) measured at two different wave lengths (λ1and λ2) of haemoglobin and of oxyhaemoglobin, in blood taken from different persons,d)sampling and treatment of the sample so that contact with air is avoided.2From the results we calculated the oxyhaemoglobin content of blood partly saturated with oxygen (0‐100% of oxyhaemoglobin) as a function of the quotient of the extinctions measured at two wave lengths.3The influence of CO‐haemoglobin was investigated.4A procedure is desc

ISSN:0165-0513    

DOI:10.1002/recl.19480671004

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractIn order to determine whether a light case of poisoning is due to carbon monoxide, we must be able to demonstrate its presence and to determine its concentration in the patient's blood. In the method developed bySayersandYantR. R. SayersandW. P. Yant, Technical Paper 373 D.O.C. Bureau of Mines (1925).tannin is added to the blood sample, by which a red precipitate is formed. The colour of the sample is compared with a series of blood‐samples containing known quantities of carbon monoxide. This method takes a long time, a sample of carbon monoxide‐free blood must be available and the accuracy is about 5% CO at the utmost. As the absorption spectra of CO‐haemoglobin (CO‐Hb), oxyhaemoglobin (O2‐Hb) and haemoglobin (Hb) are different, it is possible in principle to determine the CO in blood spectrophotometricallyK. Hinsberg, Z. Anal. Chem.121, 435 (1941)..We have examined the following factors:1The wave lengths at which the absorption by the components Hb, O2Hb, COHb is maximal and minimal.2The reproducibility of the results obtained with blood‐samples of different origin saturated with a) CO and b) O2.3The stability of COHb in bloodahaemolysed with sodium carbonatebhaemolysed with saponinctreated with air.4We have determined the extinctions at two wave‐lengths and derived the CO‐concentration from the quotient of the extinctions.5A procedu

ISSN:0165-0513    

DOI:10.1002/recl.19480671005

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractDans ce travail, on décrit plusieurs nouveauxα,β,β‐triaryléthènes substitués qui ont été synthétisés dans le but d'examiner certaines de leurs propriétés physiologiques telles que le pouvoir oestrogène. La condensation avec le cyanure de benzyle sodé de diverses diarylcétones conduit à une série d'α,β,β‐triarylacrylonitriles appartenant à des familles variées (benzène, naphthalène, acénaphthène, diphényle, etc……). Dans certain cas, les 2 stéréoisomères prévus par la théorie ont pu être effectivement isolés; en outre, il a été observé que les cétones dirivées du noyau thiophène telles que le 2‐benzoylthiophène ou le 3‐benzoyl‐2,5‐thioxène ne se condensent pas avec le cyanure de benzyle sodé à l'amidure. Enfin, desα,β,β‐triaryléthènes et α‐bromo‐α,β,β‐triaryléthènes à noyau naphtalène, acénaphtène, diphényle, et pyrrole, ont été

ISSN:0165-0513    

DOI:10.1002/recl.19480671006

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractIn studying the relations between physical constants of pure hydrocarbons, it was found that in many cases it is possible to express the constants of hydrocarbons belonging to a homologous series by an empirical formula of the type: x = x∞+ k/(c + z), wherexrepresents the physical constant of a hydrocarbon, containing c carbon atoms,x∞the limit of this physical constant at an infinite number of carbon atoms, andkandzempirical constants, characteristic for the series.Relations of this type are very valuable for control of purity of available hydrocarbon‐samples, for predicting the constants of unknown members of the series and for the analysis of hydrocarbon‐mixtures, particularly in the regions of higher molecular weight, where direct measurements of physical constants of individual hydrocarbons are scarce.This first publication of a series gives formulae of the above‐mentioned type for refraction and density at 20° C ofn‐alkanes andn‐alpha‐alkenes, and linear relations between these two constants

ISSN:0165-0513    

DOI:10.1002/recl.19480671007

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractIn continuation of the first publication of this series mathematical relations were developed between refraction, density and number of carbon atoms per molecule forn‐alkyl‐cyclopentanes, ‐cyclohexanes and benzenes. The results are compared with those of then‐alkanes andn‐alpha‐alkenes, presented in the first

ISSN:0165-0513    

DOI:10.1002/recl.19480671008

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractIn continuation of the article ofHermansJ. J. Hermans. J. Colloid Sci.2, 387 (1947).the theory is treated of the cylindrical diffusion in a medium with immobile “holes”, in which the diffusing particles are caught. This theory gives a better description ofHermans's observations than a formula ofBungenberg de Jongapplied by

ISSN:0165-0513    

DOI:10.1002/recl.19480671009

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19480671001

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY