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The UV spectra of Si-substituted silocyclobutanes in vacuum were studied. The bathochromic shift of the absorption band, disclosed by comparison with bands of the corresponding acyclic compounds, can be explained by the highly strained state of the four-membered ring. This same principle in disilocyclobutanes leads to the reduction of the barrier effect of the methylene group, disrupting the interaction of the silicon atoms in the unstrained molecule. 相似文献
4.
N. S. Nametikin V. M. Vdovin E. D. Babich V. D. Oppengeim 《Chemistry of Heterocyclic Compounds》1966,1(3):305-309
Ammonolysis of silacyclobutanes {ie305-01} (R=Cl, CH3) gives silacyelobutane di- and polysilazanes. Reaction of the disilazane {ie305-02} with 1-chloro-1-methyl-1-silacyelobutane at 20–80° gives a trisilyl-substituted amine {ie305-03}. Trisilyl-substituted amines with one silacyclobutyl group, are obtained by reacting silacyclobutanes {ie305-04} (R=CH3, C6H5). with sodium or potassium silylamides prepared from hexamethyldisilazane. It is shown that it is possible to obtain silylamides by reacting disilazanes directly with potassium metal at 90–100°. 相似文献
5.
Kinetic parameters of interphase exchange of oxygen in high-temperature proton conductors BaCe0.95Nd0.05O3- and SrCe0.95Y0.05O3- are determined using an isotope exchange method in the temperature range 630-820°C at oxygen pressures of 2.7-13.3 gPa and diffusion coefficients for oxygen are calculated. Effective energies of activation of oxygen exchange and diffusion coefficients for oxygen are calculated. Dependence of exchange characteristics and the diffusion coefficients on the oxygen pressure in the gas phase is investigated. The oxygen exchange on the surface of studied oxides is shown to proceed only with the participation of oxygen of the oxides, which causes high rates of interphase exchange of oxygen of studied cerates of barium and strontium. It is shown that the obtained data satisfactorily agree with those found in the relevant literature. 相似文献
6.
The first stage of the reaction of hexamethyldisilazane with 1-chloro-1-methyl-1-silacyclotmtane gives 1,3,3,3-tetramethyl-1,1-trimethylenedisilazane, and after that 1,3-dimethyl-1,3-bis(trimethylene)disilazane is formed. The latter reacts with 1-chloro-1-methyl-1-silacyclobutane to give tris[methyl(trimethylene)silyl] amine. From a large number of examples it is shown that transsilylation of disilazanes with chlorosilanes is a general reaction. 相似文献
7.
N.A. Sobolev V.I. Sakharov I.T. Serenkov V.I. Vdovin 《Superlattices and Microstructures》2009,45(4-5):177-181
Medium-energy ion scattering and transmission electron microscopy have been used to study the structural perfection of a Si single crystal implanted with 100 keV Si ions at a dose of 1×1017 cm?2, which exceeds the amorphization threshold by two orders of magnitude. The implantation of Si ions was found to produce a high density of extended defects without amorphization of the Si layer. The increasing depth dependence of the full width at half-minimum of the dip in angular scans of backscattered protons, was observed in a Si layer containing a high density of extended defects, in contrast to the decreasing dependence in the perfect Si crystal. 相似文献
8.
Selective chemical etching and transmission electron microscopy are used to study the defect formation in Ge1?xSix/Ge(111) epitaxial heterostructures at 0.01<x<0.35. As the Si content in the solid solution (SS) increases, the dislocation densities in the epitaxial layer, at the interface, and in the near-interface region in the substrate are found to vary nonmonotonically. The difference in the depth distribution of dislocations observed in the heterostructures in three different SS composition ranges is caused by the effect of the SS composition on the kinetics of misfit-stress relaxation, in particular, on the intensity of misfit-dislocation generation and multiplication. It is found that, in the heterostructures grown by hydride epitaxy at 600°C, misfit-dislocation multiplication through a modified Frank-Read mechanism occurs only in the range 0.03<x<0.20. The results obtained are explained in the context of the effect of silicon-rich microprecipitates, which form during the spinodal decomposition of the SS, on dislocation generation and motion in the epitaxial layer. A mechanism is proposed for misfit-dislocation generation by heterogeneous sources in the epitaxial layer; the mechanism is based on the generation of interstitial dislocation loops near microprecipitates. 相似文献
9.
V. A. Cherepenin S. A. Sokolov V. A. Vdovin 《International Journal of Infrared and Millimeter Waves》1987,8(9):1119-1128
A relativistic, two-wave generator working near -type oscillations of two lowest modes with frequency band around 8 mm, is investigated experimentally. Obtained output radiation patterns point to a single-frequency radiation character. The efficiency is found to rise in two-wave regimes in comparison with one-wave ones. The generator assembled of two sections is also considered. 相似文献
10.
V. A. Vdovin S. A. Sokolov V. A. Cherepenin A. M. Afonin V. I. Kanavetz 《International Journal of Infrared and Millimeter Waves》1987,8(1):49-54
Theoretical and experimental studies of high-power, relativistic surface-wave microwave Cherenkov generators are briefly considered. Some simulation and experiment results included, the experimentation being made in mm-wave region. 相似文献