摘要:

AbstractAn apparatus is described for the determination of the indentation hardness of organic films. The deepness of the indentation can be measured with an accuracy of 0.1 μ. The measurement is performed during the application of the force.A few results are given, indicating how the hardness of some lacquer films changes with time and thickness of the layer

ISSN:0165-0513    

DOI:10.1002/recl.19480670902

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractTill nowGerlach's internal standard method has been applied to all kinds of quantitative spectrochemical analysis. According to this method it is necessary to prepare for each individual material to be analysed series of samples in order to set up working curves, relating concentration and intensity ratio of lines of the element sought for and the standard‐element.Harvey(1947) uses the background near a line of the element as a kind of internal standard and his book contains many useful data for two‐component systems.However, materials containing many major constituents as mixtures of salts, oxides or metals themselves cannot be analysed with great accuracy according toHarvey's method.In the following paper a general method derived fromHarvey's is described; it can be divided into two parts; one for the rough estimation of the element concentration and a second part for the exact determination, obtained by successive additions of the element sought for. If the straight portion of the characteristic curve of the photographic emulsion is used, a simple evaluation of the concentration is given whereas the knowledge of the accurate shape of the characteristic curve is not essent

ISSN:0165-0513    

DOI:10.1002/recl.19480670903

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractThe complications, arising whenEvjen's method is applied to lattices, where the finite part used in the calculation has surfaces which are not electrically neutral, are investigated for a simple lattice: the CsCl lattice bounded by cube faces. A correction is calculated and is applied to the spinel lattice.

ISSN:0165-0513    

DOI:10.1002/recl.19480670904

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractAbout 0.5 ml of the gas mixture is condensed in a vessel cooled with liquid nitrogen and evaporated in the vacuum of a diffusion pump, first at −196° and subsequently at a gradually increasing temperature. The evaporated gases are collected in an evacuated chamber, where the pressure rise is measured continually. From the pressure‐time curve the relative amounts of C1, C2, C3and C4follow immediately, while in a limited number of cases the amount of ethene by the side of ethane and the amount of isobutane by the side ofn‐butane, can be measured separately.The principle of the method: higher separation efficiency at decreasing pressure, may be applied in general to all kinds of sufficiently volatile substances of which only tiny quantities are available for an

ISSN:0165-0513    

DOI:10.1002/recl.19480670905

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractAs the result of a discussion on the choice of the most suitable wavelength to be used in the photometric determination of cobalt with nitroso‐R‐salt, a wave‐length of 550 mμ is recommended, using absorption cells of 2 to 5 cm length.The interference by copper and nickel is extensively dealt with. Some data are given on the interference by other el

ISSN:0165-0513    

DOI:10.1002/recl.19480670906

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractThe determination of carbon dioxide, methane, carbon monoxide, water vapour, benzene vapour and toluene vapour by means of the Baird Infra‐Red Gas Analyser was investigated. The selectivity of the determination of methane in presence of carbon dioxide and carbon monoxide and of carbon dioxide in presence of methane and carbon monoxide was checked. An extensive investigation of the stability of the recordings brought to light that fluctuations in the frequency of the electricity supply render the recordings useless. This drawback was surmounted by feeding the infra‐red source independent of the electricity sup

ISSN:0165-0513    

DOI:10.1002/recl.19480670907

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractFundamentals of the two‐line method of emulsion calibration, in which the characteristic curve is derived from densities of two spectrum lines of constant relative intensity, photographed at different densitiy levels, are discussed.It has been found, that the principles of this method can be applied to the presentation of data obtained by any method of calibration, which is based on an intensity pattern following a geometrical series. The scope of the method is considerably widened by substitution of densities (\documentclass{article}\pagestyle{empty}\begin{document}$ \log \,\frac{{{\rm A}_{\rm o} }}{{\rm A}} $\end{document}) by densities transformed according toSeidel(\documentclass{article}\pagestyle{empty}\begin{document}$ \log \,(\frac{{{\rm A}_{\rm o} }}{{\rm A}} - 1) $\end{document}

ISSN:0165-0513    

DOI:10.1002/recl.19480670908

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractIn a previous paperR. Schmidt, Rec. trav. chim.65, 825 (1947).evidence was given that a step sector yields the same calibration curve for a photographic emulsion with either an intermittent light source or a continuous one, provided the emulsion has a negligible intermittency effect under the prevailing conditions. The data of that paper are now presented in a new way, based on that of the two‐line method and the use of densities, transformed according toSeidel, which permits more definite conclusions.Evidence is given that the step sector yields the same calibration curve as the two‐line method, in cases where it may be applied.The precision of both methods is compared; the step sector method proving to be less precise than the two‐line m

ISSN:0165-0513    

DOI:10.1002/recl.19480670909

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

摘要:

AbstractThe stability of the oxalate complexes with respect to hydrogen sulphide was studied experimentally and theoretically as a function of the pH.

ISSN:0165-0513    

DOI:10.1002/recl.19480670910

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19480670901

出版商:WILEY‐VCH Verlag    

年代:1948

数据来源: WILEY