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991.
V. M. Yakovlev D. V. Ovchinnikov I. G. Fokeeva 《Russian Journal of Applied Chemistry》2005,78(2):336-338
The dissociation energy of heteronuclear diatomic molecules with polar covalent bonds was calculated by the modified Pauling procedure taking into account the presence of an unpaired electron on one of the atoms.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 2, 2005, pp. 341–343.Original Russian Text Copyright © 2005 by Yakovlev, Ovchinnikov, Fokeeva. 相似文献
992.
A linear model is discussed to describe the phosphorus pentoxide content in the product of phosphate beneficiated by calcination, as a function of the impurities in the product. Relationships were found between the concentrations of the impurity variables in the raw material and in the product. These relationships were used to amend the model permitting prediction of the phosphorus pentoxide content in the product as a function of the composition of the raw material. 相似文献
993.
The 60 MHz room temperature pmr data of some α-nitro-β-arylstyrenes are used to assign the stereochemical configuration. The variable temperature pmr spectra exclude the presence of a rotational isomerism. The preferred conformation are then established by analysis of the chemical shifts of the heterocyclic protons. 相似文献
994.
Contributions to the Chemical Transport of Metal Oxides. V. Transport of Ternary and Quaternary Mixed Ferrites by their Chlorides The transport by means of HCl as transporting gas in a closed system in the case of the ternary mixed ferrites (Ni0,8Fe2,2O4, Mn0,75Fe2,25O4, Mn1,286Fe1,714O4) and the quaternary mixed ferrites (Mg0,5Mn0,5Fe2O4, Mg0,75Mn0,536Fe1,714O4, Mg0,281Mn0,469Fe2,25O4, Mn0,5Zn0,5Fe2O4, Mn0,5Zn0,45Fe2,05O4, Ni0,5Zn0,5Fe2O4) between T2 = 1100?1000°C and T1 = 1000?800°C was investigated. Transported crystals were characterized by chemical analysis and the saturation magnetization, the transport rate has been checked. In the case of Mn0,5Zn0,45Fe2,05O4 two phases were transported. By discussing the phase diagram an explanation is given. 相似文献
995.
The fragmentation of 4-styrylquinoline (I), 4-(p-nitrostyryl)-quinoline (II), 4-(p-chlorostyryl)-quinoline (III), 4-(p-hydroxystyryl)-quinoline (IV), 4-(p-methoxystyryl)-quinoline (V), 4-(p-dimethylaminostyryl)-quinoline (VI) and 4-(p-cyanostyryl)-quinoline (VII) under electron-impact in the mass spectrometer is reported. The role and the influence of substituents on the fragmentation scheme is discussed. The loss of the substituents from the molecular ion is correlated with LCAOMO quantities. 相似文献
996.
The synthesis, characterization, and incorporation in volatile metal-organic chemical vapor deposition (MOCVD) precursors of a new class of linked beta-ketoiminate-polyether-beta-ketoiminate ligands is presented. These ligands are designed to encapsulate alkaline-earth cations having low charges and large ionic radii. Barium complexes having the general formula Ba[(RCOCHC(R')N)2(R")] (R = tert-butyl or CF3; R' = tert-butyl, methyl, or CF3; R" = -(CH2CH2O)4CH2CH2- or -(CH2CH2O)5CH2CH2)-) were prepared and characterized by 1H and 13C NMR spectroscopy, elemental analysis, and mass spectrometry. Single-crystal X-ray diffraction analysis of 2,2,5,25,28,28-hexamethyl-9,12,15,18,21-pentaoxa-4,25-diene-6,24- diimino-3,27-pentacosadionatobarium(II) reveals a monomeric, nine-coordinate, tricapped trigonal prismatic coordination geometry. Single-crystal X-ray structural analysis of 1,1,1,24,24,24-hexafluoro-4,21-ditrifluoromethyl-8,11,14,17- tetraoxa-3,21-diene-5,20-diimino-2,23-tetracosadionatobarium(II).2DMSO reveals a monomeric, ten-coordinate, distorted tetracapped trigonal prismatic coordination geometry. Volatility data are presented for these barium complexes, demonstrating viability as MOCVD precursors. In addition, it is demonstrated that thin epitaxial films of BaTiO3 can be grown on (001) MgO by low-pressure MOCVD techniques using one of these barium complexes and Ti(dipivaloylmethanate)2(isopropoxide)2 as precursors. 相似文献
997.
We have developed a simple and physically clear picture of adiabatic rapid passage (ARP) in molecules in solution by careful examination of all the conditions needed for ARP. The relaxation effects were considered in the framework of the Landau-Zener model for random crossing of levels. The model enables us to include into consideration non-Markovian Gaussian-correlated noise. It explains all the numerical results obtained in the first paper of the series [B. D. Fainberg and V. A. Gorbunov, J. Chem. Phys. 117, 7222 (2002)], in particular, that for positive chirp pulse excitation relaxation favors more efficient population transfer with respect to the relaxation-free system with frozen nuclear motion. We also relate parameters of non-Markovian Gaussian-correlated noise with irreversible dephasing time of an optical transition by calculating the photon echo signal attenuation. 相似文献
998.
It was shown that 3-(2-oxoalkyl)-2-benzoxazolones with phenylhydrazine in the presence of polyphosphoric acid form the corresponding 2-alkyl-3-(2-benzoxazolon-3-yl)-indoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1086–1087, August, 1984. 相似文献
999.
V. D. Dyachenko S. G. Krivokolysko V. N. Nesterov V. P. Litvinov 《Chemistry of Heterocyclic Compounds》1996,32(9):1066-1074
By the condensation of an aromatic aldehyde, the anilide of acetoacetic acid, cyanothioacetamide, and Nmethylmorpholine, substituted N-methylmorpholinium 1,4-dihydropyridine-2-thiolates have been synthesized and subsequently used in the synthesis of the corresponding thiones, 2-alkylthiopyridines, thieno[2, 3b]pyridines, and disulfides. X-ray diffraction has been used to establish the structure of 2-allylthio-6-methyl-5phenylcarbamoyl-4-(2-chlorophenyl)-3-cyano-1, 4-dihydropyridine.T. G. Shevchenko Lugansk State Pedagogical Institute, Lugansk 348011. A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, Moscow 117813. N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1243–1251, September, 1996. Original article submitted May 13, 1996. 相似文献
1000.
S type Gaussian bond functions are optimized for HF, H2O, NH3, and CH4. The optimization is carried out with respect to the exponent and position in the H-X bond. The position is found to correlate
well with the electronegativity of Pauling and Allred-Rochow. 相似文献