摘要:

AbstractNous avons mesuré la conductibilité électrique du 1.8‐dihydroxynaphtalène dans une solution 0.5 molaire d'acide borique. Quoique les deux groupes hydroxyle ne soient pas vicinaux, le diol provoque une augmentation très grande de la conductibilité de l'acide borique. Ce fait pourrait être expliqué en tenant compte de la distance entre les atomes d'oxygène dans le diol par rapport à la distance entre B et O dans un dérivé du bore coordinativemen

ISSN:0165-0513    

DOI:10.1002/recl.19390580102

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

Abstractm‐Bromobenzazide was prepared in good yield by the treatment ofm‐bromobenzhydrazide with nitrous acid in glacial acetic acid solution. The azide, reacted with amines, amides aminophenols, and aminoacids in boiling toluene solution, to give, well defined crystallinem‐bromophenylureas with sharp melting points. These derivatives are suitable for the purpose of identific

ISSN:0165-0513    

DOI:10.1002/recl.19390580103

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

Abstractp‐Bromobenzazide, from nitrous acid andp‐bromobenzhydrazide, was condensed in hot ligroin solution with various kinds of alcohols, giving solid, crystalline urethanes with distinct melting points. These urethanes are considered as suitable derivatives for the identification of alcoh

ISSN:0165-0513    

DOI:10.1002/recl.19390580104

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

AbstractIn the following paper an account is given of an exact hypoiometric method for the determination of small quantities of glucose.The accuracy of the method was greatly increased by using buffered solutions in the oxidation.Probably, it is also possible to determine glucose in blood by this method.The results of a research now being carried out, may show what substances have a disturbing influence on the estimation of bloodsugar by this method.

ISSN:0165-0513    

DOI:10.1002/recl.19390580105

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

AbstractLes propriétés des “molécules remplies” se manifestent dans les éthers de l'acide méthanetétracarboxylique. Les éthers simples de méthyle et d'isopropyle (groupes compacts et symétriques) sont cristallins, alors que leurs éthers mixtes sont liquides. En comparant les éthers des acides méthanetétracarboxylique et méthanetétracétique, on constate que les premiers, qui sont plus compacts, présentent des points de fusion plus élevés et des intervalles de

ISSN:0165-0513    

DOI:10.1002/recl.19390580106

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

At −180° C the absorption spectrum of uranyl compounds has one band in common with the emission spectrum (cf. fig. 2). At room temperature, however, a new band appears in the absorption spectrum on the red side, having the same wave‐length as the dominant band of the emission spectrum, while a new band also appears in the emission spectrum on the violet side, at the same wave‐length as the principal absorption band (cf. fig. 2). This behaviour can be explained by means of the potential curves of fig. 1, giving the energy content of the UO2++ion as a function of the U‐O distance. At −180° C absorption starts only from the level 00. Temperature equilibrium is reached wit

ISSN:0165-0513    

DOI:10.1002/recl.19390580107

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

AbstractDiscussion of the mechanism of the decomposition and of the oxidation of formic acid, formaldehyde, methyl alcohol and methane at 600‐800°

ISSN:0165-0513    

DOI:10.1002/recl.19390580108

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

AbstractSchoutissenH. A. J. Schoutissen: Studies in de diazo‐chemie, thèse 19 Mars 1926, Delft; Rec. trav. chim.52, 869 (1933);53, 253 (1934); J. Am. Chem. Soc.55, 4545 (1933).a trouvé une méthode pour préparer les dihydrazines aromatiques et quelques‐uns de leurs dérivés, notamment les dihydrazones de l'éther acétylacétique. Nous avons mis cette méthode à profit pour réaliser la synthèse des diantipyrines méta et para. Cette synthèse a été effectuée par cyclisation des dihydrazones et méthylation subséquente des

ISSN:0165-0513    

DOI:10.1002/recl.19390580109

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

AbstractA discussion of the properties of an “ideal” cellulose fibre consisting of a cellulose single crystal reveals, that there is not only a large discrepancy between the theoretical tensile strength of such a fibre and the highest experimentally observed strength of actual fibres, (as already pointed out by Meyer, Mark and de Boer) but that also the ideal fibre would have an extensibility of more than 40 %, whereas the actual elongation at rupture of well oriented cellulose fibres is very much lower. From a calculation of the amount of energy necessary to bring about the rupture of the ideal fibre, it follows, that this fibre would explode after rupture.It appears therefore, that the ideal fibre as hitherto postulated, is to be regarded as a mere theoretical abstraction, which has little if any bearing on the problem of the actual mechanism of rupture.There is no certain evidence for the assumption made by previous authors, that in the actual process of rupture only cohesional attractions between primary valence chains are overcome and that there would be no rupture of the chains themselves.Irrespective as to whether in the real process of rupture primary valencies are actually broken or not, it can be shown, that the energy involved in this process, ranging between 2.108and 6.108erg/cm3, would be sufficient to bring about a considerable drop in the average chain length of the molecules in the fibre. If the energy of rupture is to any appreciable percentage connected with the rupture of molecular chains, the effect should be easily detectable by viscosity determinations. Experiments with the purpose to investigate if this effect actually exists will be undertaken.New experimental data on the energy at rupture of artificial cellulose fibres of different degrees of orientation (ranging from isotropic to extremely well oriented ones) and of commercial viscose rayon filaments, are gi

ISSN:0165-0513    

DOI:10.1002/recl.19390580110

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY

摘要:

AbstractA saturated keto‐lactone with the formula C19H26O3, has been isolated from the urine of pregnant mares. The corresponding hydroxy‐acid, C19H28O4, was obtained by saponification with alcoholic potash. The lactone has no oestrogenic or comb growth promoting eff

ISSN:0165-0513    

DOI:10.1002/recl.19390580111

出版商:WILEY‐VCH Verlag    

年代:1939

数据来源: WILEY