摘要:

Only six alkaloids, namely protopine, allocryptopine, corydaline,d-stylopine,dl-tetrahydropalmatine, and aurotensine, could be isolated from this plant. The total yield of alkaloids was approximately 0.06%. Chemically, the plant is closely allied withCorydalis ambiguaand both had been relegated to the same botanical section of the genus.

ISSN:0008-4042    

DOI:10.1139/v56-001

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The polarographic behavior of the monoximes and dioximes of 1,4-benzoquinone, 1,4-naphthoquinone, 1,2-naphthoquinone, and 9,10-anthraquinone has been investigated in the pH range 3 to 14. All of the compounds produce well-defined polarographic reduction waves which can be used for analytical purposes. Polarographic evidence indicates that the monoximes and the dioximes exhibit tautomerism.

ISSN:0008-4042    

DOI:10.1139/v56-002

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The exchange of silver ions between silver nitrate solutions and surfaces of metallic silver was studied, using radioactive silver (Ag110, 270 day half-life) as a tracer. Marked differences in behavior of surfaces prepared in different ways were observed. Crystalline (annealed and etched) surfaces exchanged rapidly to a depth of a few atomic layers, and about 80% of the acquired radioactivity was removed as quickly by exchange with inactive silver nitrate solution. Highly polished surfaces exchanged up to ten times as great an extent as the etched annealed surfaces, but required 40 hours' immersion to attain their maximum activity. The deactivation of polished surfaces by inactive solutions was inversely proportional to the period of immersion in active solution, with surfaces immersed for 17 hr. or more retaining all but 30% of their acquired activity. Abraded surfaces exchanged quickly and retained most of their activity, the extent of the exchange depending upon the ratio of “worked” to “unworked” material on the surface. Some evidence of comparatively rapid diffusion in the polish layers was obtained. The interior of cold-worked silver when exposed to the nitrate solution behaved similarly to abraded surfaces. Mechanisms for the behavior of these different types of surface are offered, and the data of other workers discussed.

ISSN:0008-4042    

DOI:10.1139/v56-003

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

The polymerization of ethylene sensitized by the thermal decomposition of ethyl iodide in the presence of mercury vapor has been studied at 250°, 275°, and 300 °C. C14-labelled ethyl iodide was used in a number of experiments. The increase in the rate of decomposition of ethyl iodide in the presence of ethylene and the formation of butyl iodide are accounted for by equilibrium processes of the type RI + Hg = R + HgI. The important features of the reaction were established from the identity, quantity, and activity of the various products. The predominant formation of olefins is attributed to the isomerization and decomposition of large radicals. Very little of the butane is formed by the combination of ethyl radicals. Radical disproportionation is the most important chain termination step.

ISSN:0008-4042    

DOI:10.1139/v56-004

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Solutions of the second order non-linear differential equation of spherical diffusion flames have been obtained for the range of conditions of experimental interest. Deviations from the simplified exponential solution are presented in a form suitable for their direct evaluation. Some recent contributions to the theory of the method are discussed.

ISSN:0008-4042    

DOI:10.1139/v56-005

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Mixtures of the radionuclides Na22and Na24, as the chloride salts, have been partially separated by chromatographic methods. A column 102 cm. in length containing the cation exchange resin Dowex 50 was used. The eluant was 0.7 Mhydrochloric acid. Na22is held more strongly by the resin than is Na24. The most effective separations were obtained at 25 °C and 5.5 °C.; experiments at 48 °C and 68 °C showed much smaller isotope effects.

ISSN:0008-4042    

DOI:10.1139/v56-006

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

Benzophenone has been reduced to benzhydrol with three samples of isobutylmagnesium bromide containing deuterium in thealpha,beta, andgammapositions, respectively. Deuterium was found only in the benzhydrol obtained from β-deuteroisobutylmagnesium bromide. Comparison of the ratios of deuterium to protium in β-deuteroisobutylmagnesium bromide and in the benzhydrol obtained from it shows an isotope effect of about two. In the decarboxylation of hydroxyl-deuterated dimethylmalonic acid an isotope effect of 4.5 was observed. These results are considered in terms of the probable mechanisms of the reactions.

ISSN:0008-4042    

DOI:10.1139/v56-007

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v56-008

出版商:NRC Research Press    

年代:1956

数据来源: NRC

摘要:

not available

ISSN:0008-4042    

DOI:10.1139/v56-009

出版商:NRC Research Press    

年代:1956

数据来源: NRC