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21.
M. V. Kirichkov A. A. Guda A. P. Budnyk T. A. Lastovina A. L. Bugaev V. V. Shapovalov Yu. V. Rusalev A. V. Chernyshev A. V. Soldatov 《Journal of Structural Chemistry》2017,58(7):1403-1410
A colloidal solution of gold nanoparticles is synthesized with the use of sodium tetrachloroaurate(III) as a precursor, oleylamine as a reducer and surfactant, and 1-octadecene as a solvent. Reaction stages are analyzed in situ by optical (UV-vis) absorption spectroscopy with a simultaneous analysis of particle sizes by dynamic light scattering and X-ray absorption near edge spectroscopy for the analysis of the gold oxidation state. After the synthesis the size of obtained nanoparticles is determined by transmission electron microscopy. The analysis of the obtained experimental data reveals the presence of three main steps in the reduction reaction mechanism, corresponding to Au3+, Au+, Au0, which enables the construction of the reaction model. The reaction mechanism involves the formation of gold(I) complexes with oleylamine, followed by polymerization and the formation of gold nanoclusters coated with oleylamine. 相似文献
22.
Bruno Therrien Julien Freudenreich Sergey S. Shapovalov Laurent Plasseraud 《Journal of organometallic chemistry》2010,695(3):409-1919
A series of neutral, anionic and cationic arene ruthenium complexes containing the trichlorostannyl ligand have been synthesised from SnCl2 and the corresponding arene ruthenium dichloride dimers [(η6-arene)Ru(μ2-Cl)Cl]2 (arene = C6H6, PriC6H4Me). While the reaction with triphenylphosphine and stannous chloride only gives the neutral mono(trichlorostannyl) complexes [(η6-C6H6)Ru(PPh3)(SnCl3)Cl] (1) and [(η6-PriC6H4Me)Ru(PPh3)(SnCl3)Cl] (2), the neutral di(trichlorostannyl) complex [(η6-PriC6H4Me)Ru(NCPh)(SnCl3)2] (3) could be obtained for the para-cymene derivative with benzonitrile as additional ligand. By contrast, the analogous reaction with the benzene derivative leads to a salt composed of the cationic mono(trichlorostannyl) complex [(η6-C6H6)Ru(NCPh)2(SnCl3)]+ (5) and of the anionic tris(trichlorostannyl) complex [(η6-C6H6)Ru(SnCl3)3]− (6). On the other hand, [(η6-PriC6H4Me)Ru(μ2-Cl)Cl]2 reacts with SnCl2 and hexamethylenetetramine hydrochloride or 18-crown-6 to give the anionic di(trichlorostannyl) complex [(η6-PriC6H4Me)Ru(SnCl3)2Cl]− (4), isolated as the hexamethylenetetrammonium salt or the chloro-tin 18-crown-6 salt. The single-crystal X-ray structure analyses of 1, 2, [(CH2)6N4H][4], [(18-crown-6)SnCl][4] and [5][6] reveal for all complexes a pseudo-tetrahedral piano-stool geometry with ruthenium-tin bonds ranging from 2.56 (anionic complexes) to 2.60 Å (cationic complex). 相似文献
23.
R. N. Nurmukhametov A. V. Shapovalov A. M. Sergeev N. S. Kushakova I. A. Khotina 《Journal of Applied Spectroscopy》2011,78(1):31-37
A branched oligophenylene has been synthesized based on 1,3,5-tri(4′-bromophenyl)benzene. Absorption and fluorescence spectra
were studied and fluorescence quantum yields and lifetimes were measured for the compound in solution. It is demonstrated
that the absorption spectrum is a superposition of p-quaterphenyl, p-terphenyl, and biphenyl chromophore absorption bands
in a 1:2:1 ratio. The oligomer fluorescence spectrum is found to depend on the excitation wavelength. It is shown that the
oligomer fluorescence is determined by two fluorochromic groups, namely fragments with branched p-terphenyl and p-quaterphenyl
units. The main fluorescence maxima for these fluorochromic groups coincide with each other and lie in the vicinity of λ =
360 nm. A very weak fluorescence band found in the region 380–440 nm is excited by light with a wavelength lying beyond the
oligomer self-absorption region. The reasons for a decrease in fluorescence quantum yields of branched models and the studied
oligophenylene as compared with those of linear p-polyphenylene chromophores are discussed. 相似文献
24.
R. N. Nurmukhametov A. V. Shapovalov A. M. Sergeev A. I. Kovalev N. S. Kushakova I. A. Khotina 《Journal of Applied Spectroscopy》2011,78(3):344-351
Absorption spectra and fluorescence parameters (spectra, quantum yields, and lifetimes) were obtained for a number of branched
oligophenylenes (OPh) with long-wavelength chromophores such as p-quaterphenyl (OPh4-2), p-pentaphenyl (OPh5), and p-hexaphenyl (OPh6) and for oligofluorenylphenylenes (OFl) in solutions and films. It is demonstrated that the absorption spectrum
of OPh4-2 is a superposition of p-quaterphenyl, p-terphenyl, and diphenyl absorption bands taken in a ∼3:2:2 ratio. The obtained OPh5 and OPh6 absorption and fluorescence
spectra are shown to be determined mainly by the longest-wavelength chromophores, p-pentaphenyl and p-hexaphenyl, respectively. It is demonstrated that the obtained compounds contain traces of impurities with fluorescence at
longer wavelengths than that of the base material. The branched oligomers exhibit high fluorescence quantum yields in solutions,
those for OPh5 and OPh6 reaching 1. Transparent fluorescent films were produced from all of the synthesized oligomers. 相似文献
25.
All the subalgebras of first-order symmetry operators for the d'Alembert equation, generating the bases of solutions in the
method of noncommutative integration of linear differential equations, which cannot be constructed in the method of separation
of variables, are found. These bases themselves are then given in explicit form. The complete systems of solutions of the
d'Alembert equation, determined by noncommutative sets of first-order symmetry operators, are thereby classified.
Tomsk State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 25–30, June, 1998. 相似文献
26.
A. A. Pasynskii S. S. Shapovalov I. V. Skabitskii O. G. Tikhonova 《Russian Journal of Coordination Chemistry》2017,43(12):837-842
Syntheses and molecular structures of the heterometallic complexes of nickel cyclopentadienyl triphenylphosphine tellurophenolate with tungsten carbonyls (II and III) (CIF files CCDC nos. 1559733 and 1559734, respectively) are described. 相似文献
27.
V. M. Shapovalov S. V. Lapshina 《Journal of Applied Mechanics and Technical Physics》2004,45(1):45-53
Equations of spatial motion of a curved finitelength rod in a viscous fluid flow are derived. Analytical solutions of problems on the motion of a straight rod under conditions of pure shear, simple shear, and uniaxial extension of the fluid are obtained. Longitudinal stability of the straight rod during its spatial motion is considered. Effective viscosity of a suspension filled by rigid straight rods is evaluated. 相似文献
28.
The tendency of anions of sulfophthaleine dyes to heteroassociation was studied in aqueous solutions of phenol red, cresol
red, thymol blue, and non-substituted phenol red. It was spectrophotometrically determined that single (HAn−) and doubly charged anions (An2−) of sulfophthaleines can form stable heteroassociates of the composition Ct+ · HAn− and (Ct+)2 · An2− with cations (Ct+) of polymethine dyes, pinacyanol, and quinaldine red. The values of enthalpy formation of ions of dyes and heteroassociates
were calculated semi-empirically and compared with experimentally determined values of the equilibrium association constants. 相似文献
29.
A. M. Valenkov I. V. Gofman K. S. Nosov V. M. Shapovalov V. E. Yudin 《Russian Journal of Applied Chemistry》2011,84(5):735-750
Most widely occurring classes of carbon nanoparticles used to create polymeric composite systems are considered. The possibility
is demonstrated of using “polymer-carbon nanoparticles” composites for raising the level of mechanical properties of polymeric
materials, creating friction units with improved tribological characteristics, developing new electrochemical, microelectronic,
and optical devices, and modifying barrier properties of polymeric membranes. Methods for treatment of nanoparticles to provide
their compatibility with polymeric matrices and preclude their aggregation are discussed. 相似文献
30.
A classification is performed of massless gauge fields admitting one first-order symmetry operator of special type for the Dirac equation in Minkowski space. The gauge group is chosen to be SU(3). The factors multiplying the derivatives of the symmetry operator do not contain generators of the gauge group, which allows us to classify the fields according to symmetry operators of the free Dirac equation.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 22–21, June, 1989. 相似文献