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1.
V. V. Kuznetsov Yu. V. Ermolenko A. Ya. Zheltov K. A. Kornev S. V. Sheremet'ev 《Journal of Analytical Chemistry》2004,59(1):17-22
The coprecipitation of azo compounds based on 4-nitrophenyl- and 4-sulfophenyldiazonium naphthol sulfonates as their diphenylguanidinium ion-pair complexes with analogous compounds of naphthalene-2-sulfonic acid and 4-phenylsulfodiazonium is investigated. The optimization of the coprecipitation is considered based on the notions of the driving force of the cocrystallization of impurities. The optical characteristics of colored ion-pair complexes are measured. It is found that the water solubility is decreased most substantially for azosulfonates with hydrophobic nitro groups and with no more than two sulfo groups in different aromatic nuclei, which can lead to a decrease in the detection limit due to preconcentration by coprecipitation, which stimulates the thermodynamic flux of concentrate elution. Coprecipitation is combined with flow-injection analysis in the on-line mode, and new procedures are developed for determining naphthol sulfonates and related azo compounds with the detection limit equal to 0.003–0.006 mg/50 mL. 相似文献
2.
A. N. Kornev O. S. Donnikova V. V. Semenov Yu. A. Kurskii 《Russian Chemical Bulletin》1995,44(1):145-148
A method for preparing (trichloromethyl)organosilanes by the catalytic decarboxylation of the corresponding trichloroacetoxysilanes RMe2SiOC(O)CCl3 (R = Me, ClCH2, Ph, Me3Si, and H) has been developed. The method involves heating the starting compounds without a solvent in the presence of a catalyst (quaternary ammonium salts or potassium salts with the addition of crown ethers). Tertiary amines (Et3N, Bu3N) catalyze this reaction only when heating is carried out in donor aprotic solvents (THF, acetonitrile) in the presence of oxygen. Thermal decomposition of (trichloroacetoxy)organosilanes, in contrast to catalytic decarboxylation, begins at a higher temperature and yields a mixture of products.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 150–153, January, 1995. 相似文献
3.
L. G. Klapshina V. V. Semenov A. N. Kornev V. S. Rusakov O. I. Shchegolikhina A. A. Zhdanov G. A. Domrachev 《Russian Chemical Bulletin》1998,47(3):478-481
The photochemical interaction of polyphenylferrisiloxane with some oligoorganosilanes in benzene solutions has been studied by UV, IR, ESR, and Mössbauer spectroscopy. Silylene species formed during photolysis of oligoorganosilanes react with the high-spin iron(III) to reduce the latter to low-spin iron(II). The formation of the low-spin state of iron(II) was supported by measurements of the magnetic moments. The insertion of the silylene species into the polymer chain to form the Fe?Si bond occurs due to the photoreaction. 相似文献
4.
Reactions of organo(trichloromcthyl)silanes RMc2SiCCl3 (R = Me, Ph, Mc3Si) with aluminum chloride have been studied. The interaction of trimetltyl(tricltlorometltyl)silane with AlCl3 carried out in cyclohexane or in benzene leads to Me3SiCHCI2 (in 75 % yield) or ClMe2SiCPh2Me (in 70 % yield), respectively; whereas no conversions are observed inn-hexane and methylene chloride. Treatment of dimetltyl(phenyl)(ricltloromethyl)silane with aluminum chloride in an-C5H12/CH2CI2 mixture gives an aromatic cross-linked insoluble polymer. The reaction of pentamethyl(trichloromcthyl)disilane (R = Mc3Si) with AICl3 in pentane affords the rearrangement product, Me3SiCCl2SiMc2Cl, in 65 % yield. In methylene chloride the further cleavage of the disilane occurs to yield Me2SiCl2 and CH2=CHMe2SiCl.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1511-1515, June, 1996. 相似文献
5.
V. V. Semenov N. F. Cherepennikova A. N. Kornev E. V. Naamova N. P. Makarenko S. Ya. Xhorshev G. A. Domrachev O. A. Bochkova 《Russian Chemical Bulletin》1996,45(10):2431-2437
Oligo(phenylcobaltcarbonylsilane) was prepared from oligo(phenylsilane) and dicobalt octacarbonyl. The reaction proceeds with elimination of H2 and CO and insertion of cobalt carbonyl fragments into the silicone backbone of oligosilane. Oligosilane containing cobalt carbonyl groups in side organic substituents was obtained from oligolmethyl(phenylethynyl)Isilane and CO2(CO)8. The reaction of 1,2-bis(phenylethyny1)tetramethyldisilane with Co2(CO)8 proceeds with the sequential attachment of cobalt carbonyl fragments to ethynyl groups to form disilane derivatives [2-CCPhCo2(CO)6] Thermal decomposition of cobalt-containing oligosilanes affords a mixture of paramagnets and ferromagnets.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya. No. 10, pp. 2561–2567, October, 1996. 相似文献
6.
M. M. Shakirtov A. P. Shabanov V. M. Kornev 《Journal of Applied Mechanics and Technical Physics》2013,54(2):308-314
The process of tension of a plate with a narrow crack-like cut whose vertices form finite-radius semi-circumferences is considered. The plate is made of a structured material whose mechanical characteristics are close to the characteristics of St.45 steel. Fracture diagrams are constructed by a numerical method, based on the necessary and sufficient criteria. A possibility of an analytical presentation of fracture diagrams is demonstrated. 相似文献
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9.
A. A. Kornev 《Moscow University Mathematics Bulletin》2016,71(3):106-110
The problem of construction of first kind boundary conditions providing an asymptotic change of the trivial solution of a model one-dimensional RBMK reactor to the required stationary state is numerically studied according to specific features of this model. Results of calculations are presented for different admissible modes. The principal feasibility of efficient stabilization of the dynamics of occurring processes by boundary control of fast and slow neutrons is shown as well as its essential slow-down in the control of only fast neutrons. 相似文献
10.