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51.
The transitions of relativistic electrons in a magnetic field with the emission of an antineutrino-neutrino pair are considered. Probabilities are obtained for electron transitions to the ground state and weakly excited states. It is shown that in the case of an ultrastrong magnetic field (HHo=m2c3/e=4.41·1013 G) such transitions made a considerable contribution to the total probability of the process.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 110–114, March, 1978.In conclusion, the authors express their profound gratitude to A. A. Sokolov for his attention to our work. 相似文献
52.
A. A. Vilisov V. P. Germogenov N. K. Maksimova L. E. Épiktetova 《Russian Physics Journal》1980,23(4):284-289
A calculation is made of the dependences of the coefficient of the tellurium distribution KTe and the electron concentration n in AlxGa1–xSb on the composition of the solid solution and the growth temperature. It is shown that KTe must decrease with increasing x. The dependence of KTe on the temperature is also determined by x. Experimental results were obtained on AlxGa1–x Sb (0 x 0.74) films grown by liquid epitaxy. The electron concentration in the films was measured through the thermoelectric power and the capacitance-voltage characteristics of Schottky barriers. Satisfactory agreement with the results of the calculation was obtained.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 19–25, April, 1980.We thank G. K. Arbuzov for assistance in preparing the surface-barrier structures. 相似文献
53.
Érika Pinto Marinho A. G. Souza Danniely S. de Melo Iêda M. G. Santos Dulce M. A. Melo Walquíria J. da Silva 《Journal of Thermal Analysis and Calorimetry》2007,87(3):801-804
Because
of their electrical, magnetic and catalytic properties rare earth and transition
metal mixed oxides are important compounds. Lanthanum chromites have been
extensively used as solid oxide fuel cell (SOFC) interconnect materials. In
this work, lanthanum chromites partially substituted by alkaline earth metals
were synthesized by the urea combustion process. TG and DSC techniques were
used to evaluate the presence of the organic material in the powder after
reaction on the hot plate. The powders were calcinated at 900°C and characterized
by XRD and SEM. The results show that the particles have nanometric dimensions
and the perovskite structure was formed. 相似文献
54.
Within the Born-Oppenheimer adiabatic perturbation theory, an equation was obtained for the intensity of fast electron scattering
by polyatomic molecules. All of its parameters are explicitly defined by vibronic interaction in a molecule; due to this,
quantum chemical calculations are fully applicable to electron diffraction studies of molecular geometries.
Engels Anti-Aircraft Missile Higher Military School. Translated fromZhurmal Strukturnoi Khimii, Vol. 35, No. 2, pp. 40–45, March–April, 1994.
Translated by L. Smolina 相似文献
55.
Yu. B. Vysotskii V. V. Volodarets É. G. Éilazyan L. S. Gutyrya 《Theoretical and Experimental Chemistry》1995,31(4):184-188
A MINDO/3 calculation based on the Hartree—Fock perturbation theory gave the atom—atom self- and mutual polarizabilities of a series of hydrocarbons. A study was carried out on the effect of the perturbation-induced distortion of the electron—electron interaction and molecular relaxation on the calculated values.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 31, No. 4, pp. 227–231, July–August, 1995. 相似文献
56.
B. A. Arbuzov O. Éxsner A. P. Timosheva V. E. Kataev S. G. Vul'fson A. N. Vereshchagin 《Russian Chemical Bulletin》1976,25(6):1206-1212
1. | The dipole moments of the two kinds of C-O bonds in acetals and their analogs are not identical. |
2. | In formal molecules and the dimethylketal of acetone the C-O-C-O -C chains have gauche-gauche conformation, with the methyl groups lying on different sides of the O-C-O plane. |
3. | The dimethylketal of tetrachlorocyclopentadienone is represented by a mixture of trans-gauche and gauche-gauche conformers. |
57.
N. V. Bausk S. B. Érenburg L. G. Lavrenova L. N. Mazalov 《Journal of Structural Chemistry》1995,36(6):925-931
EXAFS spectroscopy is used to investigate the characteristic features of the spatial and electronic structure of the polynuclear Fe(II) complexes Fe(ATR)3A2 (where A is the NO 3 ? , BF 4 ? , Br?, or ClO 4 ? anion and ATR is 4-amino-1,2,4-triazole) and their magnetically diluted phases FexZn1?x(ATR)3(NO3)2. The absolute distances from Fe and Zn to the surrounding atoms are determined at temperatures higher and lower than the spin transition point. In all complexes, the spin transition is accompanied by significant changes in the local environment of Fe atoms, while in the magnetically diluted phases the surrounding of zinc remains unchanged. It is shown that addition of Zn atoms distorts the triazole rings in the low-spin state of the complexes. No localized anions were revealed within 3.3 Å from the Fe and Zn atoms. It is shown that a decrease in the spin transition temperature correlates with an increase in Fe?N distances in the low-spin complexes due to magnetic dilution and substitution of anions in the series NO 3 ? , BF 4 ? , Br?, ClO 4 ? of ATR-containing complexes. 相似文献
58.
F. FRÉZARD A. GARNIER-SUILLEROT C. DEMICHELI 《Journal of inclusion phenomena and macrocyclic chemistry》1997,28(1):51-62
The recent discovery that mithramycin(MTR) in aqueous solution forms a high affinity[Ca(MTR)4]2- complex led us to the idea thatCa2+-loaded liposomes might be able to accumulateMTR in their aqueous internal compartment. Wetherefore investigated the uptake of MTR into largeunilamellar vesicles (LUV) containing NaCl orCaCl2. Our data show that MTR was efficientlyaccumulated within LUV made fromdipalmitoylphosphatidylcholine and cholesterol, onlywhen the liposomes contained Ca2+ and wereresuspended in a Ca2+-free medium. A drugencapsulation efficiency as high as 60% was achieved,at a drug to lipid molar ratio of 1/18. The circulardichroism and fluorescence excitation spectra ofliposome-encapsulated MTR (LMTR) displayed strongsimilarities with those of the [Ca(MTR)4]2-complex. LMTR was found to be stable, when submittedto conditions that destabilized the[Ca(MTR)4]2- complex. Upon dilution andincubation for 24 h at 37 °C, MTR-containingliposomes did not release a significant amount of MTR.These properties were attributed to the formation ofa high affinity complex between MTR and Ca2+inthe aqueous compartment of liposomes. 相似文献
59.
N. S. Prostakov I. V. Shendrik B. N. Anisimov A. V. Varlamov A. A. Fomichev S. Lavani-Édogiaverie 《Chemistry of Heterocyclic Compounds》1982,18(10):1085-1088
It was demonstrated by PMR spectroscopy that mixtures of N-oxides of 6- and 7-nitro derivatives are formed in the nitration of the N-oxides of 3-methyl-2- and 4-azafluorenes. The products were deoxygenated to give nitro derivatives of 2- and 4-azafluorenes. The N-oxides of nitro-substituted azafluorenes were converted to salts of the aci forms by the action of alkali.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1396–1399, October, 1982.The authors thank K. F. Turchin for his assistance in recording the spectrum of nitration product VI at 200 MHz. 相似文献
60.
Glucose utilization by lysine-producing fluoroacetate-sensitive mutants ofCorynebacterium glutamicum
A fluoroacetate-sensitive mutant was isolated fromCorynebacterium glutamicum, ATCC 21513, following mutagenesis with NTG. Batch fermentations show that in terms of growth kinetics, glucose utilization,
and lysine formation, there are significant differences between the mutant and the parent. The mutant’s specific growth rate
(0.22/h) is lower than that for the parent (0.34/h). Also, the yield expressed as lysine/glucose consumed does not alter as
a function of the glucose concentration for the mutant, and is about 0.22, whereas for the parent, this coefficient decreases
with increasing glucose concentration. The maximum specific rate of lysine production for the mutant is 1.3 g/L/h that is
about two-fold higher than that for the parent. 相似文献