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Dr. Volodymyr Sashuk Dr. Oksana Danylyuk 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(19):6528-6531
A ruthenium carbene complex bearing azobenzene functionality is reported. The complex exists in the form of two isomers differing by the size of the chelate ring. Both isomers were isolated by applying kinetic or thermodynamic control during the synthesis and characterized by X‐ray diffraction analysis. The isomerization of the complex was studied by UV/Vis spectroscopy. The stable isomer was tested as a catalyst in olefin metathesis. The complex was activated at about 100 °C to promote ring‐closing and ring‐opening polymerization metathesis reactions. The activation took place also at room temperature under middle ultraviolet radiation. 相似文献
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The dynamic Hartree-Fock theory with point-like interaction is used to calculate the speed of sound and damping factor of a zero-sound wave propagating in a degenerate Fermi gas. This wave propagates slower than Fermi velocity. It is shown, that if the interaction is weak and density is small, then the damping of such a wave can be small. A possibility of discovering such waves in ultracold Fermi gases is discussed. 相似文献
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Andrij Stetskiv Beata Rozdzynska‐Kielbik Volodymyr Pavlyuk 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(7):683-688
A new ternary dithulium hexacobalt icosastannide, Tm2.22Co6Sn20, and a new quaternary thulium dilithium hexacobalt icosastannide, TmLi2Co6Sn20, crystallize as disordered variants of the binary cubic Cr23C6 structure type (cF116). 48 Sn atoms occupy sites of m.m2 symmetry, 32 Sn atoms sites of .3m symmetry, 24 Co atoms sites of 4m.m symmetry, eight Li (or Tm in the case of the ternary phase) atoms sites of symmetry and four Tm atoms sites of symmetry. The environment of one Tm atom is an 18‐vertex polyhedron and that of the second Tm (or Li) atom is a 16‐vertex polyhedron. Tetragonal antiprismatic coordination is observed for the Co atoms. Two Sn atoms are enclosed in a heavily deformed bicapped hexagonal prism and a monocapped hexagonal prism, respectively, and the environment of the third Sn atom is a 12‐vertex polyhedron. The electronic structures of both title compounds were calculated using the tight‐binding linear muffin‐tin orbital method in the atomic spheres approximation (TB–LMTO–ASA). Metallic bonding is dominant in these compounds, but the presence of Sn—Sn covalent dumbbells is also observed. 相似文献
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Iryna Chepurna Valentyn Kanibolotsky Volodymyr Strelko 《Journal of Sol-Gel Science and Technology》2013,68(3):500-508
Hydrated zirconium dioxide samples were synthesized via original sol–gel route by two-step neutralization of zirconium oxychloride. Spherical granules of zirconia materials were prepared using a well-known “oil-drop” method. By the use of low temperature nitrogen adsorption, it is shown that surface fractal dimension of synthesized xerogels strongly depends on synthesis conditions, chemical and hydrothermal treatments. It is established that the change of synthesis conditions allows to obtain zirconium containing materials with developed porous structure: BET surface area—250–450 m2/g, pore diameter—2.0–4.2 nm, surface fractal dimension—2.28–2.63. It is shown that surface fractal dimension is an important parameter allowing to control the final properties of synthesized material and to determine the reasons of non-reproducibility of adsorptive, catalytic and other physical and chemical properties of zirconium containing oxides from synthesis to synthesis. 相似文献
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Obernikhina Nataliya V. Kachaeva Maryna V. Kachkovsky Oleksiy D. Brovarets Volodymyr S. 《Chemistry of Heterocyclic Compounds》2022,58(8-9):412-420
Chemistry of Heterocyclic Compounds - For the estimation of the biological affinity of nitrogen-containing π-conjugated heterocyclic systems toward amino acid residues in proteins, the... 相似文献
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Volodymyr Babizhetskyy Volodymyr Levytskyi Régis Jardin Josef Bauer Roland Guérin Régis Gautier Bruno Fontaine Jean-François Halet 《无机化学与普通化学杂志》2020,646(14):1168-1175
Two novel ternary borosilicides R9Si15–xB3 (R = Tb, x = 1.80, R = Yb, x = 1.17) were synthesized from the initial elements using tin flux method. Their crystal structures were determined by means of X-ray single crystal diffraction. Both refer to space group R32, Z = 1: a = 6.668(2) Å, c = 12.405(4) Å [R1 = 0.027, wR2 = 0.031 for 1832 reflections with Io > 2σ (Io)] for Tb9Si15–xB3, and a = 6.5796(3) Å, c = 12.2599(5) Å [RF = 0.052, wR = 0.090 for 1369 reflections with Io > 2σ (Io)] for Yb9Si15–xB3. The structures represent a new structure type, derived from that of AlB2, with ordering in the metalloid sublattice resulting in distorted [Si5B] hexagons. The presence or absence of boron in this ordered structure is discussed on the basis of difference Fourier syntheses, interatomic distances, structural analysis, and theoretical calculations in relation with the parent structures of the binaries AlB2 and Yb3Si5 (Th3Pd5 type of structure). Theoretical calculations show substantial covalent interactions between the metal and nonmetal elements. The small percentage of silicon atoms, which are missing in these nonstoichiometric compounds, probably allows strengthening boron-metal and boron-silicon bonding. 相似文献
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