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911.
It was established that the yields of a 4-allyl-4-aryl-aminopiperidines in the reaction of 4-aryliminopiperidines with allylmagnesium bromide increase significantly if the reaction is carried out in the presence of a crown ether. A number of previously unknown spiro[tetrahydroquinoline-2,4-piperidines] were obtained in the cyclization of 4-allyl-4-arylaminopiperidines in the presence of sulfuric acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1514–1519, November, 1989.  相似文献   
912.
913.
We study spin collective modes in paramagnetic systems using a sum rule approach. We give a simple and analytical expression for the static magnetic polarizability of finite size systems in terms of their radii and of the magnetic susceptibility of a uniform system. A systematics for the mean excitation energy of spin modes in clusters and shells is given. In metal spheres, the hydrodynamical model is solved and compared with the sum rule approach. An estimate for the mean excitation energy of the spin dipole collective state in fullerene is given.  相似文献   
914.
915.
Extractive substances formed from buckwheat grain production waste   总被引:1,自引:0,他引:1  
Properties of liquid and dry extracts produced in treatment of buckwheat fruit shells (husk) and straw with water or an acid solution were studied. The conditions of pigment concentration from aqueous extracts by ultrafiltration were determined.  相似文献   
916.
The effect of doping with CdS nanoparticles of recording medium films for the thermoplastic holographic recording process, which are based on photosemiconductors (oligomers and cooligomers of glycidylcarbazole) and a dielectric (a styrene copolymer with octyl methacrylate) containing a photoconductivity sensitizer, on their photosensitivity was studied. The enhancement of photosensitivity of films by doping with nanoparticles is associated with the appearance of an additional channel for transport of electrons generated from sensitizer molecules. A difference in informational properties between the oligomer and the polymer films was revealed.  相似文献   
917.
An unusual path for the reaction of 2-aryl-1-dimethylamino-2H-isoindoles with N-R-maleimides, leading to the imides of l,2-dihydronaphthalene-2,3-dicarboxylic adds, was established by x-ray crystallographic analysis.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 614–618, May, 1992  相似文献   
918.
The dependence of the rate of a photochemical reaction of XeO4with H2on the concentrations of H2and the diluent gases He and CO2is studied at room temperature. The results are compared with the data for the dark reaction. A mechanism with the elementary energetic branched-chain reaction OH (v) + XeO4OH + O + XeO3is proposed to explain the results of the study.  相似文献   
919.
Conclusions The cis-trans isomers of the vinylic fluorine substitution product were isolated and characterized when Na[5-C5H5Fe(CO)2] is reacted with ethyl perfluoromethacrylate.Deceased.The authors express their gratitude to E. M. Rokhlin and U. Utebaev for supplying the ethyl perfluoromethacrylate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 705–706, March, 1977.  相似文献   
920.
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