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1.
In the present work, the general method proposed earlier for calculating the distribution density and moments of the absorbed energy in isolated sensitive regions of absorbers irradiated by ionizing particles is developed and made specific for the electron-photon problem. Electron transfer is considered within the framework of a model using grouping of excitations and slipping ionization; the presence of electron equilibrium in the vicinity of sensitive regions is assumed. Two similar methods of calculating these characteristics are developed. Both reduce the initial problem to two independent problems: determining the electron spectrum in the sensitive region (in one of the methods, the spectrum of electron sources is also needed) and calculating the coefficients characterizing electron transfer in the sensitive region and its immediate vicinity.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 89–94, September. 相似文献
2.
The results of a calculation of the characteristics of fluctuations in the absorption of energy of electrons and gamma rays in small sensitive volumes of a material in electronic equilibrium are presented. The calculations were performed by the method developed in [1]. The efficiency and accuracy of the method are demonstrated by comparisons with the experimental results and direct numerical simulation. The experience gained in using the method is analyzed. The main numerical result of this work is a table of coefficients enabling the calculation of the probability of the absorption of energy and the first two moments of the energy absorbed in spherical regions with radii of 1, 2, 4, and 8 m, starting only from the electronic spectrum in these regions, for water absorbers with arbitrary shape and arbitrary electronic or photonic sources with energies up to 1 MeV.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 77–82, February, 1988. 相似文献
3.
I. P. Trifonova V. A. Burmistrov A. S. Ocheretovyi O. I. Koifman 《Russian Journal of General Chemistry》2007,77(6):1078-1085
Inner-sphere replacement of alcohols by imidazole and its derivatives in the complex (acetato)-(tetraphenylporphyrinato)chromium(III) was studied by electronic absorption spectroscopy. The rate constants and activation parameters of the process were calculated. The entering ligand structure was shown to affect the reaction rate, while the alcohol nature (departing ligand) does not influence the kinetic parameters of the process to an appreciable extent. Regression analysis revealed participation of imidazole and ethanol in the rate-determining stages. The kinetic equation for the inner-sphere axial substitution implies interaction of a free alcohol molecule with that coordinated to chromium, followed by replacement of the associate by the heteroring. Mathematical processing of the kinetic data in terms of the proposed solvolytic association-dissociation mechanism gave the rate constants for particular stages of the process and showed an extremal relation between the rate constant and composition of the solvent. 相似文献
4.
Conclusions Prototropic rearrangement in the phenyl radical cannot proceed under ordinary conditions in view of the high energy barrier.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 460–462, February, 1979. 相似文献
5.
V. F. Borodkin V. A. Burmistrov M. K. Islyaikin 《Chemistry of Heterocyclic Compounds》1981,17(1):49-51
The PMR spectra of the macroheterocyclic compound obtained by the reaction of 5-tert-butyl-1,3-diiminoisoindoline with 1,3-phenylenediamine in refluxing butyl alcohol and purified by chromatography on aluminum oxide were recorded. It is shown that the compound does not contain a unified conjugated macroring system. The dependence of the chemical shift of the protons of the endocyclic imino groups on the nature of the solvent was investigated. It is shown that the formation of compound-solvent intermolecular hydrogen bonds is complicated by steric factors.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 62–64, January, 1981. 相似文献
6.
Alkylation of 2-amino-4,5-dimethylthiazole with isopropanol and cyclohexanol in 85% sulfuric acid gives good yields of isopropylamino- and 2-cyclohexylamino-4,5-dimethylthiazole. The structures of the products are demonstrated by reverse synthesis from 3-chlorobutanone and substituted thioureas.For Part III see [1]. 相似文献
7.
2-Chloro-3-formylquinoxaline was synthesized from 2-chloro-3-methylquinoxaline by the Kröhnke method, and the properties of its phenylhydrazone were studied. It was found that 2-Y-3-formylquinoxalines display an anomalously low reactivity as compared with 2-Y-benzoylquinoxalines (Y=H, OH, Cl) in the synthesis of pyrazolo[3,4-b]quinoxalines.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 852–856, June, 1973. 相似文献
8.
X-ray powder diffraction and thermogravimetry (TG) are used to study the solid compounds formed upon joint hydrolysis of antimony pentachloride and phosphoric acid in the molar ratio range of 1.35 < Sb/P < 12. The products retain the pyrochlore structure motif intrinsic to crystalline polyantimonic acid, the increasing phosphorus concentration deteriorates the degree of crystallinity of the products. Contributions of various factors into diffraction peak broadening are ascertained. The effect of phosphorus on the structure of the products is discussed on the basis of X-ray powder diffraction and TG data. 相似文献
9.
V. I. Zaikovskii A. P. Shepelin V. A. Burmistrov A. N. Startsev Yu. I. Yermakov 《Reaction Kinetics and Catalysis Letters》1984,25(1-2):17-22
Differences in the structure of WS2 samples with SBET=7.6 and 75 m2/g are manifested in decreasing lengths of basal faces of some small crystallites in the more dispersed WS2. This effect increases the relative fraction of lateral faces on the catalyst surface. Ni ions in the Ni/WS2 catalysts are in an electrondeficient state compared to NiS.
WS2 7,6 2/qg 75 2/ WS2. Ni Ni/WS2 ( NiS) .相似文献
10.
I. I. Furlei E. A. Burmistrov F. Z. Galin V. N. Iskandarova G. A. Tolstikov 《Russian Chemical Bulletin》1987,36(11):2296-2300
Conclusions The fragmentation of substituted cyclopropanes under the conditions of dissociative electron capture is accompanied by the opening of the cyclopropane ring and is determined by the nature of the functional group. The increase in the number of electron-acceptor substituents noticeably stabilizes the molecular negative ions.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2473–2478, November, 1987. 相似文献