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991.
V.?B.?Kosterev Yu.?F.?Ivanov V.?E.?GromovEmail author O.?Yu.?Efimov S.?V.?Konovalov 《Russian Physics Journal》2012,54(9):1034-1045
Results of investigations of the structure-phase state and dislocation substructure formation during thermomechanical hardening
of Fe–0.09C–2Mn–1Si steel in different regimes are presented. Methods of transmission electron microscopy reveal the formation
of gradient states characterized by regular changes of the structure, phase composition, types, and parameters of the dislocation
substructures over the structure cross section. 相似文献
992.
N. N. Koval Yu. F. Ivanov A. P. Laskovnev V. V. Uglov N. N. Cherenda Yu. A. Kolubaeva Ye. A. Markova A. D. Teresov P. V. Moskvin 《Russian Physics Journal》2012,54(9):1024-1033
A film/substrate system has been treated with a submillisecond high-intensity electron beam. Examinations have shown that
the electron-beam treatment of the film/substrate system resulted in alloying of the surface layer of the material throughout
the melt which was accompanied by the formation of nanodimensional phases. 相似文献
993.
M. Ivanov J. Krug 《The European Physical Journal B - Condensed Matter and Complex Systems》2012,85(2):72
We report new results on the non-conserved dynamics of parallel steps on vicinal surfaces in the case of sublimation with
electromigration and step-step interactions. The derived equations are valid in the quasistatic approximation and in the limit
f
-1 ≫ l
D
≫ l
± ≫ l
i
, where f is the inverse electromigration length, l
D
the diffusion length, l
± the kinetic lengths and l
i
the terrace widths. The coupling between crystal sublimation and step-step interactions induces non-linear, non-conservative
terms in the equations of motion. Depending on the initial conditions, this leads to interrupted coarsening, anticoarsening
of step bunches or periodic switching between step trains of different numbers of bunches. 相似文献
994.
Mentink JH Hellsvik J Afanasiev DV Ivanov BA Kirilyuk A Kimel AV Eriksson O Katsnelson MI Rasing T 《Physical review letters》2012,108(5):057202
We propose a general theoretical framework for ultrafast laser-induced spin dynamics in multisublattice magnets. We distinguish relaxation of relativistic and exchange origin and show that when the former dominates, nonequivalent sublattices have distinct dynamics despite their strong exchange coupling. Even more interesting, in the exchange dominated regime sublattices can show highly counterintuitive transitions between parallel and antiparallel alignment. This allows us to explain recent experiments with antiferromagnetically coupled sublattices, and predict that such transitions are possible with ferromagnetic coupling as well. In addition, we predict that exchange relaxation enhances the demagnetization speed of both sublattices only when they are antiferromagnetically coupled. 相似文献
995.
E. N. Viktorova A. A. Korolev V. A. Ivanov T. R. Ibragimov A. A. Kurganov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(9):1473-1478
Monolithic capillary columns based on polydivinylbenzene with monolith structure, optimized for the separation of high-molecular compounds, are synthesized. The structure of the monolith is optimized by varying the chemical composition of the porogene. It is shown that monolithic columns with the maximum amount of free volume can be obtained by using a porogene consisting of nonanol and toluene or mesitylene. On the basis of Van Deemter functions measured for the synthesized columns, it was concluded that for sorbates differing strongly in molecular weight and thus their diffusion coefficients, we cannot find a single optimum flow rate, and the optimum separation of polymeric sorbates requires that we reach a certain compromise. It was shown that in these circumstances, monolithic columns with the optimum structure of monolite allow almost completely separation of a mixture of 15 low molecular weight polymeric sorbates into individual components. 相似文献
996.
M. A. Shevchenko M. I. Ivanov V. V. Berezutski V. G. Kudin V. S. Sudavtsova 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(12):1779-1784
Partial and integral mixing enthalpies of melts of binary systems Mn-Sc and Mn-Y at 1873 and 1830 K, respectively, are determined by calorimetry. It is found that the minima of the mixing enthalpies are ?7.1 ± 0.4 and -3.2 ± 0.2 kJ/mol at x Mn = 0.60 and 0.61, respectively. The initial partial mixing enthalpies of Sc and Y are ?33.2 ± 2.1 and ?16.6 ± 0.8 kJ/mol, respectively. The thermodynamic properties of melts of binary Mn-Sc(Y) systems are calculated using the ideal associated solution (IAS) model. It is found that the activities of the components exhibit slight negative deviations from the ideal solutions, and the excess Gibbs energies reach ?3.0 and ?1.6 kJ/mol, respectively. 相似文献
997.
M. V. Rogozina V. N. Ionkin A. I. Ivanov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(4):667-674
The processes of intramolecular electron transfer from the second excited electron state accompanied by superfast reverse
transfer to the first excited state are studied. The kinetics of the populations of the first and second excited states, along
with that the charge-separated states, is calculated within the generalized stochastic model, taking into account the reorganization
of the medium and intramolecular high-frequency vibrations. It is shown that variations in the relaxation rate of the high-frequency
vibrational modes can change the population of the quenching products by a factor of two to three. It is established that
in the case of the weak exothermicity of the charge separation process, the population of the charge-separated states declines
upon an increase in the vibrational relaxation rate, while the population of the first excited state increases; in the region
of high exothermicity, these dependences change to ones that are opposite. To reveal the scales of these effects in real systems,
the kinetics of the photo-induced processes in the zinc-porphyrin derivatives, including electron-acceptor imide groups covalently
coupled with porphyrin rings, are calculated. It is shown that the results from calculating the kinetics of the population
of the first and the second excited states agree well with the experimental data on the kinetics of the fluorescence of these
states. The absolute values of the population of the charge-separated state and the first excited state are determined. The
key role of the hot electron transitions that occur in parallel with the relaxation of the medium and intramolecular vibrations
in the considered process is shown. 相似文献
998.
Franck Thibault Laura Gomez Sergey V. Ivanov Oleg G. Buzykin Christian Boulet 《Journal of Quantitative Spectroscopy & Radiative Transfer》2012,113(15):1887-1897
We perform dynamical calculations on two robust N2–N2 potential energy surfaces in order to intercompare pressure broadening coefficients derived from close coupling and coupled states quantum dynamical methods, the semi-classical model of Robert and Bonamy and a full classical method. The coupled states and full classical results compare well with the experimental results or with close coupling values when available. This study confirms that the classical method is a good alternative at room and high temperatures to quantum dynamical methods. The results obtained using the semi-classical method however deviate from the other sets of data at all temperatures considered here (77–2400 K). 相似文献
999.
Nonlinear absorption of laser radiation with a photon energy exceeding the half-width of the direct band gap of crystal but lower than its width has been considered. It is shown that, in the case of singlephoton resonance at transitions between two conduction bands, even at radiation intensities j ??105?C106 W/cm2, there is a range of j values where the optical absorption and concentration of nonequilibrium electron-hole pairs sharply increase with an increase in j. The transition of the material between states with different optical and electric properties occurs for few nanoseconds. 相似文献
1000.
Danov KD Stoyanov SD Vitanov NK Ivanov IB 《Journal of colloid and interface science》2012,368(1):342-355
Here we present the exact solution of two approaching spherical droplets problem, at small Reynolds and Peclet numbers, taking into account surface shear and dilatational viscosities, Gibbs elasticity, surface and bulk diffusivities due to the presence of surfactant in both disperse and continuous phases. For large interparticle distances, the drag force coefficient, f, increases only about 50% from fully mobile to tangentially immobile interfaces, while at small distances, f can differ several orders of magnitude. There is significant influence of the degree of surface coverage, θ, on hydrodynamic resistance β for insoluble surfactant monolayers. When the surfactant is soluble only in the continuous phase the bulk diffusion suppresses the Marangoni effect only for very low values of θ, while in reverse situation, the bulk diffusion from the drop phase is more efficient and the hydrodynamic resistance is lower. Surfactants with low value of the critical micelle concentration (CMC) make the interfaces tangentially immobile, while large CMC surfactants cannot suppress interfacial mobility, which lowers the hydrodynamic resistance between drops. For micron-sized droplets the interfacial viscosities practically block the surface mobility and they approach each other as solid spheres with high values of the drag coefficient. 相似文献