摘要:

AbstractIn order to find a quantitative method for determining the carotene content in plant material and feces (for use in physiological resorption experiments) we have worked over again and compared the methods known from various earlier publications. A secondary aim was to find a useful method which may be applied as routine analysis in other laboratories to obtain reproducible and comparable results. None of the known methods proved to be generally applicable, although for some materials they sufficed.The following points were specially studied: 1. The determination of carotene concentration with the aid of the Zeiss Stufenphotometer. The extinction values published in earlier studies have been checked. 2. The separation of carotene from other pigments. This is only possible with adsorbents as aluminium oxide and calcium hydroxide. The losses which usually occur could be eliminated by a slight modification of the adsorption‐elution technique. 3. The extraction of the material. Simple continual extraction with ethyl alcohol in a Berntrop flask gives quantitative results. It is suitable for routine analysis. In the case of grass ensilated with acid, the extraction with alcoholic potassium hydroxide according to Guilbert is necessary. However this method gave no quantitative results with other materials. Results and description of the methods are given belo

ISSN:0165-0513    

DOI:10.1002/recl.19420611002

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractDie im Titel genannte Verbindung wird durch Synthese erhalten, wobei das 3‐Cyan‐4,6‐dimethylpyridon‐2 als Ausgangsproduk

ISSN:0165-0513    

DOI:10.1002/recl.19420611003

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractThe preparation of pure pyrosulphuryl chloride S2O5Cl2is described. The Raman spectrum of the liquid has been determined and polarization measurements have been effected. For the molecule the structure ClO2S‐O‐SO2Cl has been deduced. Each sulphur atom is tetrahedrally surrounded by the four atoms attached to it. The spatial configuration is such that two vertical planes of symmetry and a twofold axis are present in the molecule (symmetry C2v). An assignment of the frequency shifts found to the normal vibrations of the molecule of the symmetry C2vhas been given. Some remarks are made about the molecular structure of pyrosulphuric a

ISSN:0165-0513    

DOI:10.1002/recl.19420611004

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractVapour pressures of phosphorus oxybromide were measured between 150° and 205°C. The boiling point was calculated to be 192.0°C. The heat of evaporation is 10.9 kcal/mol, the constant of Trouton 23, both at the boiling point.Combination of high temperature and strong daylight decomposes this compou

ISSN:0165-0513    

DOI:10.1002/recl.19420611005

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractIn this paper the relations between the volumes of dry fibres and fibres with different percentages of regain are discussed. With the aid of these relations and based on the opinion, that a solid substance will not sorb a liquid with appreciable contraction, the conclusion is reached that water will be sorbed by hydrophylic fibres in three ways, viz.:1byabsorption in the outer layer of the micelles,2byadsorption at the micelle surface without contraction, and3by capillary condensation also without contraction.The effect of the felting process and dyeing processes on the quantity of water sorbed, and more generally on the sorptive capacities of the fibres cotton, silk and wool is discussed.

ISSN:0165-0513    

DOI:10.1002/recl.19420611006

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractAdrenochrome has a promoting effect on the migration of bone marrow in vitro, in experiments as described by Overbeek, Gaillard and de Jongh to test and standardize liver extract on its anti‐anaemic properties. This promoting effect, however, is atypical in comparision with that of liver extract. (The commercial preparation Pernaemon was used

ISSN:0165-0513    

DOI:10.1002/recl.19420611007

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

摘要:

AbstractThe determination of the dipole moments of some cyclanes was carried out in the undiluted liquid.For purposes of comparison and for the determination of the refraction some other hydrocarbons were also measured.

ISSN:0165-0513    

DOI:10.1002/recl.19420611008

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19420611001

出版商:WILEY‐VCH Verlag    

年代:1942

数据来源: WILEY