摘要:

AbstractIn the previous paperMiss A. E. Korvezee and P. Dingemans, Rec. trav. chim. 62, 625 (1943).) we showed that the relative vapour pressure of saturated salt solutions (i.e. the vapour pressure of the solution divided by the vapour pressure of water at the same temperature), plotted as a function of the temperature, is in many cases a straight or only very slightly curved line.When a salt occurs in two crystalline forms which are converted into each other at a definite temperature, the p‐T curve of the saturated solutions will possess two maxima (stable or metastable), and there are three different types of curve possible. An example of each type has been exhaustively studied in this laboratory. By making use of all the vapour pressures measured over a wide temperature range, the equations of the relative vapour pressure curves are given for these saturated solutions. With the help of these equations the position of the maxima in the p‐T curves can be accurately determined.From the difference in the slope of the relative vapour pressure curves at the transition point, the heat of transition between the two modifications of the salt can be calculated. This heat effect can also be calculated as the difference in heat of crystallization of the two salt modifications at the temperatures of the max

ISSN:0165-0513    

DOI:10.1002/recl.19430621002

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

AbstractA very simple approximate expression (equation 5) is derived for the relation between the melting point of a solid substance and the temperature at which a maximum occurs in the three‐phase pressure curve solid substance‐saturated solution‐vapour.An expression is also given (equation 7) for the distance between the temperatures of the two maxima in the three‐phase pressure curves, when the solid substance occurs in two modifications. Both equations are found to agree well with the observations for all the now known systems wat

ISSN:0165-0513    

DOI:10.1002/recl.19430621003

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

AbstractDas von Veldstra und Wiardi beschriebene Acetylsulfanilylderivat des 5‐Aminotetrazols isnicht5‐Acetylsulfanilamidotetrazol, und kann deshalb nicht bei der Hydrolyse 5‐Sulfanilamidotetrazol bilden. Das wahre 5‐Acetylsulfanilamidotetrazol gibt aber auch nicht bei der Hydrolyse 5‐Sulfanilamidotetrazol, sondern unterliegt einer Ringsprengung. Auch bei Einwirkung von Sulfanilsäurefluorid auf 5‐Aminotetrazol gelang es nicht, das 5‐Sulfanilamidotetrazo

ISSN:0165-0513    

DOI:10.1002/recl.19430621004

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

AbstractThe arguments of Jensen and Rosenlund HansenK. A. Jensen, O. Rosenlund Hansen, Rec. trav. chim.) in support of their opinion that the tetrazoles described in our first paperH. Veldstra, P. W. Wiardi, Rec. trav. chim. 61, 627 (1942).) are not 5‐acetylsulphanilyl‐aminotetrazole (and 5‐sulphanilylaminotetrazole), butx‐acetylsulphanilyl‐5‐aminotetrazole (andx‐sulphanilyl‐5‐aminotetrazole) are considered unconvincing.It is shown that the substances possess the structure we ascribed to them. It proves to be possible to isolate three tautomeric forms of 5‐acetylsulpha

ISSN:0165-0513    

DOI:10.1002/recl.19430621005

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

AbstractThe activity of atomic hydrogen as a polymerization agent for unsaturated organic compounds has been investigated. Two methods were used to prepare pure atomic hydrogen. The first was a modified Langmuir method, passing hydrogen over a glowing tungsten wire, and removing the hydrogen ions formed. The second was Cario and Frank's method, by which atomic hydrogen is prepared by means of ultraviolet light. It could be shown that atomic hydrogen causes polymerization as well as hydrogenation of unsaturated organic compounds.

ISSN:0165-0513    

DOI:10.1002/recl.19430621006

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

AbstractWe have studied the haemolysing action of lysocithin on the chromocytes of man, rabbit and sheep. It was found that the amount of lysocithin needed to haemolyse a red cell is sufficient to cover this cell by a monomolecular layer. In view of the fact that lysocithin alters the shape (and therefore the surface) of the chromocytes before haemolysis sets in, no very accurate check is possible.The lysocithin used was prepared from egg‐yolk. In a series of preliminary experiments with lyosocithin prepared from ovolecithin Merck the general features of lysocithin haemolysis were studied. It was shown that the number of chromocytes haemolysed by a given quantity of lysocithin is independent of the concentrations used. And further, that the process of lysocithin haemolysis is terminated within less than 15 minutes, even if insufficient lysocithin is present for the haemolysis to be complet

ISSN:0165-0513    

DOI:10.1002/recl.19430621007

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

AbstractIn this article the X‐ray investigation of tetramethylorthothiocarbonate C(SCH3)4is described, a compound of particular interest with regard to its physical properties1). The modification stable below 23.2°C proved to be tetragonal, space groupP421c(D2d4)Z= 2,a= 8.536 Å,c= 6.949 Å.A Bragg synthesis showed that the molecule C(SCH3)4is built tetrahedrally withC‐S= 1.81 Å. The structure can be simply described as a packing of methyl groups (r= 2 Å) arranged in a pattern resembling a body‐centred lattice, the interstices of which are alternately empty, or filled with

ISSN:0165-0513    

DOI:10.1002/recl.19430621008

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

Abstract1)The consistency of a plastic suspension of the Bingham type was characterized by deriving φ‐τ diagrams from theD‐τ diagrams.2) In the case of the plastic suspensions of carbon in mineral oil it is deduced from the φ‐τ relation that the temperature coefficient of the consistency is determined almost entirely by the medium of suspension.3) Attention is called to the large errors caused by the turbulence occurring during measurements at high shearing stresses.4) In order to describe the curved part of aD‐τ diagram more exactly by means of constants, the concept of liquidation tendency is introduced. This liquidation tendency can be read off directly from

ISSN:0165-0513    

DOI:10.1002/recl.19430621009

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

摘要:

AbstractNaNO2, orthorhombic hemihedral at ordinary temperature, shows an abrupt change in the temperature coefficients of the cell constants at about 158°C. At this same temperature the original strong piezo‐electric effect disappears. The change is very probably caused by the occurrence of two symmetrical sets of atomic positions in “averaged struct

ISSN:0165-0513    

DOI:10.1002/recl.19430621010

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19430621001

出版商:WILEY‐VCH Verlag    

年代:1943

数据来源: WILEY