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881.
The dispersion characteristics of a plasma in a pump field ??(t) = ?? sub ω0t + ??1 sin ω1t are considered. Firstly we assume, that the second wave is weak (|??1| ? |??0|) and the frequency ω1 is near sω0(ω1 = sω0 + Ω,Ω ? ω0). We obtain the dispersion equation, describing the parametric coupling of the waves driven by the strong field ??0 sin ω0t under the resonance condition ω0 ≈ ωLe/P and derive the expressions for the growth rates (ωLe is the electron LANGMUIR frequency; s, p are integers). In the second part it is shown, that a strong field ??1 with a frequency ω1 much larger than ω Le(ω Le ≈ pω0) stabilizes the plasma; the growth rates are reduced and the frequency region of the parametric instability is contracted. 相似文献
882.
L. V. Sereda Ya. Yu. Aliev I. B. Romanova E. F. Litvin 《Chemistry of Heterocyclic Compounds》1971,4(5):603-605
A method has been elaborated for the quantitative gas-chromatographic analysis of a mixture of piperidine, N-formylpiperidine, and pyridine on polyethylene glycol-4400 applied onto a chromosorb and NaCl, and apezon L, applied onto NaCl. The relative retentive volumes and heats of solution of the components of the mixture were calculated. 相似文献
883.
M.R. Aliev 《Journal of Molecular Spectroscopy》1974,52(2):171-176
Expressions in terms of molecular parameters are obtained for the sextic centrifugal distortion constants HJ, HJK, HKJ, and HK of axially symmetric molecules. A numerical example for the NH3 molecule is given which shows that the sextic distortion of NH3 is normal. It is emphasized that the observed sextic distortion constants provide additional information on the cubic anharmonic potential coefficients. 相似文献
884.
A. G. Gamzatov A. M. Aliev Sh. B. Abdulvagidov A. B. Batdalov O. Yu. Gorbenko 《Russian Physics Journal》2007,50(4):383-386
Temperature dependences (77–300 K) of the thermal capacity, diffusion, and conductivity are investigated for the Nd
0.5
Sr
0.5
MnO
3 and Nd
0.55
Sr
0.45
MnO
3 polycrystalline samples. The examined characteristics show anomalous behavior in the magnetic phase transition and transition
to the charge-ordered state. It is demonstrated that the main reason for a sharp decrease in the thermal conductivity during
Nd
0.5
Sr
0.5
MnO
3 transition into the antiferromagnetic charge-ordered state is a change in the phonon spectrum caused by the lattice compression.
A temperature dependence of the free phonon path is calculated for the examined temperature interval based on the thermal
diffusion obtained and the literature data on the sound propagation velocity.
__________
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 72–75, April, 2007. 相似文献
885.
V. Sh. Aliev V. N. Votentsev A. K. Gutakovskii S. M. Maroshina D. V. Shcheglov 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2007,1(4):454-461
Morphological transformations of amorphous vanadium oxide films obtained by the sol-gel method and polycrystalline V2O5 films are studied during their low-temperature (295–623 K) reduction in a hydrogen electron cyclotron resonance plasma. The morphology of films is analyzed using atomic force microscopy and high-resolution electron microscopy. It is found that a homogeneous amorphous film during the reduction process transforms to an island film and then bulk amorphous islands of a regular shape appear. These islands resemble microcrystals, and their concentration depends on the temperature and the reduction time. The low-temperature reduction of polycrystalline V2O5 films leads to their amorphization; however, the microcrystals in the polycrystalline film do not change their shape in this process. A mechanism of the reduction process is proposed. This mechanism explains the regularities of morphological transformations in amorphous sol-gel films of vanadium oxides based on the suggestion of a competition between the ion-stimulated nucleation and growth of nuclei of the crystalline phase and the amorphization of the growing nuclei. 相似文献
886.
T.M. Aliev K. Azizi A. Ozpineci 《The European Physical Journal C - Particles and Fields》2007,51(3):593-599
Using three point QCD sum rule methods, the form factors relevant to semileptonic Bs→DsJ(2460)ℓν decay are calculated. The q2 dependences of these form factors are evaluated and compared with the heavy quark effective theory predictions. The dependence
of the asymmetry parameter α, characterizing the polarization of the DsJ meson, on q2 is studied. The branching ratio of this decay is also estimated, and it is shown that it can easily be detected at LHC. 相似文献
887.
N. B. Babanly I. I. Aliev G. A. Azizov M. B. Babanly 《Russian Journal of Inorganic Chemistry》2007,52(1):126-128
The quasi-ternary system Tl2Se-AgTlSe-TlBiSe (A) has been investigated by DTA, X-ray powder diffraction, microstructural analysis, and microhardness measurements. Polythermal sections AgTlSe-TlBiSe2, AgTlSe-Tl9BiSe6, [Ag0.5Tl1.5Se]-TlBiSe2, Tl2Se-AgBiSe2 (0–50 mol % AgBiSe2), an isothermal section at 500 K, and the projection of the liquidus surface of system A have been constructed. It has been shown that the quasi-binary join AgTlSe-Tl9BiSe6 divides system A into two subordinate triangles, namely, Tl2Se-Tl9BiSe6-AgTlSe (B) and AgTlSe-Tl9BiSe6-TlBiSe2 (C). The phase diagram of subsystem B involves a univariant eutectic equilibrium while subsystem C involves an invariant eutectic equilibrium. The ternary eutectic has the coordinates 650 K, 10 mol % TlBiSe2, and 61 mol % AgTlSe. A continuous series of solid solutions (0–12 mol % AgTlSe) has been found along the Tl2Se-Tl9BiSe6 bordering system. The homogeneity region of TlBiSe2 extends to 5 mol %. 相似文献
888.
N. L. Racheva S. N. Shurov Z. G. Aliev A. N. Maslivets 《Russian Journal of Organic Chemistry》2007,43(1):108-116
3-Aroyl-2,4-dihydro-1H-pyrrolo[2,1-c][1,4]benzoxazine-1,2,4-triones react with N-unsubstituted and N-substituted 3-amino-5,5-dimethylcyclohex-2-en-1-ones to give 3′-aroyl-4′-hydroxy-1′-(o-hydroxy-phenyl)-6,6-dimethyl-6,7-dihydrospiro[indole-3,2′-pyrrole]-2,4,5′(1H,1′H,5H)-triones. The molecular and crystalline structure of the 1-cyclohexyl-substituted derivative was studied by X-ray analysis. 相似文献
889.
N. Yu. Lisovenko A. N. Maslivets Z. G. Aliev 《Russian Journal of Organic Chemistry》2007,43(1):117-120
Aroyl(quinoxalinyl)ketenes generated by thermolysis of 5-aryl-4-(quinoxalin-2-yl)-2,3-dihydrofuran-2,3-diones react with N-benzylideneanilines and N,N’-dicyclohexylcarbodiimide according to the [4+2]-cycloaddition pattern where the aroylketene acts as diene, and C=N component, as dienophile, to give 3-aryl-2-(2,3,6-triaryl- and 6-aryl-3-cyclohexyl-2-cyclohexylimino-4-oxo-3,4-dihydro-2H-1,3-oxazin-5-yl)quinoxalines. The structure of two cycloaddition products was proved by X-ray analysis. 相似文献
890.
The results of the ring conformational analysis of L-proline, N-acetyl-L-proline, and trans-4-hydroxy-L-proline by NMR combined with calculations using density functional theory (DFT) and molecular dynamics (MD) are reported. Accurate values of 1H-1H J-couplings in water and other solvents have been determined. Using a two-site equilibrium model, the Cgamma-endo conformer of L-proline in water has been identified as intermediate between gammaTdelta [twist(Cgamma-endo, Cdelta-exo)] and gammaE [envelope(Cgamma-endo)] and the Cgamma-exo conformer as betaTgamma. Both conformers were equally populated at room temperature. The N-acetyl [cis-rotamer gammaTbeta(80%)/gammaE(20%) and trans-rotamer gammaTbeta(61%)/gammaE(39%)] and 4-hydroxy (gammaEpsilon) derivatives showed significant changes in both the population and the geometries of the preferred ring conformers. The combination of NMR predicted populations with the DFT B3LYP/6-311+G(2d,p)/IEFPCM calculations proved successful, resulting in fairly accurate predictions of J-couplings. Simulations using MD were mostly in favor of the two-site equilibrium model between Cgamma-endo and Cgamma-exo conformers, similar to that used for the analysis of NMR J-couplings. Various force fields examined for MD simulations failed to reproduce the ring conformational geometries and populations of L-proline in water accurately, while significantly better agreement with NMR was found for trans-N-acetyl-L-proline using GROMOS and AMBER force fields. 相似文献