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101.
M. Yu. Antipin Yu. T. Struchkov I. F. Shishkov A. V. Golubinskii T. L. El'fimova L. V. Vilkov A. A. Bredikhin A. N. Vereshchagin S. M. Ignatov V. F. Rudchenko R. G. Kostyanovskii 《Russian Chemical Bulletin》1986,35(10):2040-2046
Conclusions It has been established by the methods of x-ray diffraction analysis and electron diffraction analysis and measurements of the dipole moments and the birefringence that in the crystalline and gaseous phases, as well as in solution, N,N-dimethoxyamine has a gauche-gauche conformation, which is stipulated by a stabilizing nO-N-O* orbital interaction. The geometric parameters of the molecule have been determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2235–2242, October, 1986. 相似文献
102.
L.S. Khaikin A.V. Belyakov G.S. Koptev A.V. Golubinskii L.V. Vilkov N.V. Girbasova E.T. Bogoradovskii V.S. Zavgorodnii 《Journal of Molecular Structure》1980
The geometrical parameters of tris(trimethylstannyl)amine have been determined by gas-phase electron diffraction. The a structure has been refined using mean amplitude values calculated from the force fields of a number of tin derivatives.The experimental data are consistent with a planar bond configuration at the nitrogen in N(SnMe3)3. The final set of geometrical parameters is as follows (average bond distances, rg , in Å, angles in degrees): SnC 2.166(5), SnN 2.038(3), CH 1.117(17). NSnC 108.5(1.5), SnCH 112.1(1.6). Mean amplitude values have been varied for those distances which give considerable contributions to scattering.The results obtained fill a gap in the knowledge of structures of Group IV element μ-nitrido derivatives. They confirm the conclusion that lowering of ligand MRn electro-negativity weakens the tendency to deviation from planarity in the central fragment NM3. This tendency may be considered as a manifestation of the second-order Jahn-Teller effect. 相似文献
103.
N. I. Popik M. V. Popik V. S. Mastryukov A. L. Detistova L. V. Vilkov A. Almenningen J. Brunvoll 《Journal of Structural Chemistry》1989,30(5):843-844
Chemistry Faculty, M. V. Lomonosov Moscow State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 5, pp. 172–173, September–October, 1989. 相似文献
104.
The experimental and quantum-chemical values of dihedral angles are analyzed for mono- and bicyclic molecules. Correlations have been found for the bond and dihedral angles. 相似文献
105.
E. G. Atavin A. V. Golubinskii M. V. Popik V. V. Kuznetsov N. N. Makhova L. V. Vilkov 《Journal of Structural Chemistry》2003,44(5):779-783
Gas-phase electron diffraction using quantum-chemical calculations was employed to study the molecular structure for 6,6'-bis(1,5-diazabicyclo[3.1.0]hexane). The conformation of the bicyclic fragment is boat or anti relative to the exocyclic bond. 相似文献
106.
E. G. Atavin A. V. Golubinskii A. N. Kravchenko O. V. Lebedev L. V. Vilkov 《Journal of Structural Chemistry》2005,46(3):417-421
The structure of the mebicar molecule has been studied by gas-phase electron-diffractometry using quantum chemical calculations. An eclipsed conformation along the C-C bond (torsion angle ?(H-C-C-H) = 10°) and flattened semi-chair conformations of cyclic fragments have been found. The bond lengths (r g ) and angles (∠α) show the following average values: r(C-C) 1.576(3) Å, r(C-N) 1.460(3) Å, r(C(O)-N) 1.390(4) Å, r(C=O) 1.211(5) Å, r(C-H) 1.090(5) Å, ∠CCN 103.0(5)°, ∠CNC(O) 112.2(1)°, ∠CNC 122.4(1)°. The dihedral angle between the cyclic fragments is 116.6°. 相似文献
107.
Geometric parameters of dimethylphenylphosphine molecule were determined by gas-phase electron diffraction using a dynamic model in which the rotation of the PMe2 group is treated as large-amplitude motion. Refinement of the structural parameters and parameters of the potential function was performed taking into account the geometry relaxation on the basis of HF/6-311++G** calculations. The internal rotation potential has a single minimum at 0° ( is the angle between the bisector of the MePMe angle and the phenyl ring plane) and may be described by the function of the form V() = 0.5V
2(1 - cos2), where V
2 = 0.38±0.36 kcal mol-
1. The data obtained are compared with those for related molecules. Steric effects affect the geometry of the phenylphosphine molecule more significantly than does p- interaction. 相似文献
108.
Khaikin L. S. Grikina O. E. Zhilinskaya E. A. Zhilinskii B. I. Vilkov L. V. 《Russian Chemical Bulletin》2002,51(11):2014-2025
Geometric parameters and the force fields of the molecule of 2-chloro-1,3-dimethyl-2,3-dihydro-1H-1,3,2-benzodiazaphosphole, C6H4(NMe)2PCl (1), and the 1,3-dimethyl-2,3-dihydro-1H-1,3,2-benzodiazaphospholium cation, C6H4(NMe)2P+ (2), containing a dicoordinated P atom were calculated by the restricted Hartree—Fock (RHF) method using the 6-31G* and 6-311G** basis sets. Vibrational characteristics of the internuclear distances in molecule 1 were calculated using the a priori scaled force field. Structural analysis of the gas-phase electron diffraction data for this molecule was performed with inclusion of nonlinear kinematic effects at the first-order level of perturbation theory. Substantial lengthening of the P—Cl bond and conformational peculiarities of the phosphole fragment of molecule 1 are consistent with the expected manifestations of the anomeric effect. The type of partial localization of the -bonds in the benzene fragment (relative weights of two resonance Kekule structures, or the Mills—Nixon effect) changes on going from covalent to ionized state of the P atom in the annelated five-membered ring. 相似文献
109.
L. S. Khaikin O. E. Grikina V. A. Shlyapochnikov L. V. Vilkov C. W. Bock 《Russian Chemical Bulletin》1995,44(11):2039-2052
Ab initio geometries and vibrational spectra have been calculated for the amine structures of dinitramine and methyldinitramine, HN(NO2)2 and CH3N(NO2)2. It is shown at the RHF and MP2 levels with the use of the 6-31G* and 6-31G** basis sets that these molecules have different symmetries in their equilibrium states,C
sandC
1 respectively. The quantum chemical RHF/6-31G* force fields were scaled with the set of transferable factors previously obtained by the authors to assign the available experimental vibrational bands and predict the positions of bands for the unmeasured spectral regions. Some common patterns of the geometrical parameters, vibrational spectra, and force fields of the simplest nitramines are discussed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2135–2147, November, 1995.The authors are grateful to the Russian Foundation for Basic Research (Project No. 93-03-4410) and to the International Science Foundation (Grant No. MQXOOO) for financial support of works fulfilled at the Department of Chemistry, M. V. Lomonosov Moscow State University. The authors also acknowledge the support of the Scientific Technical Program Universities of Russia. 相似文献
110.
G. S. Grebenyuk M. V. Gomoyunova O. Yu. Vilkov B. V. Sen’kovskii I. I. Pronin 《Physics of the Solid State》2016,58(10):2135-2140
The silicon intercalation under single-layer graphene formed on the surface of an epitaxial Co(0001) film was investigated. The experiments were performed under conditions of ultra-high vacuum. The thickness of silicon films was varied within the range of up to 1 nm, and the temperature of their annealing was 500°C. The characterization of the samples was carried out in situ by the methods of low-energy electron diffraction, high-energy-resolution photoelectron spectroscopy using synchrotron radiation, and magnetic linear dichroism in photoemission of Co 3p electrons. New data were obtained on the evolution of the atomic and electronic structure, as well as on the magnetic properties of the system with an increase in the amount of intercalated silicon. It was shown that the intercalation under a graphene layer is accompanied by the synthesis of surface silicide Co2Si and a solid solution of silicon in cobalt. 相似文献