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81.
O. Yu. Ovsitser Z. G. Osipova V. D. Sokolovskii 《Reaction Kinetics and Catalysis Letters》1989,38(1):91-94
The catalytic activities in ammoxidation of cyclohexane to adiponitrile (ADN) was compared with the phase compositions of Ti–Sb–O catalysts. It was shown that the reaction is limited by the step of ADN desorption from the catalyst.
Ti–Sb–O (). , .相似文献
82.
O. A. Petrov G. V. Osipova B. D. Berezin O. I. Nikolaeva 《Russian Journal of Coordination Chemistry》2005,31(11):809-813
The acid-base interaction of octa(p-bromophenyl)tetraazaporphine with nitrogen-containing organic bases in benzene-DMSO system is studied. The structures of the proton-transfer complexes formed in the reaction are suggested. The reaction rate, activation parameters, and mechanism of intermolecular transfer of protons of the NH groups of octa(p-bromophenyl)tetraazaporphine to a base were shown to be determined by the nature of the proton-acceptor molecules. The dielectric permeability of a binary solvent was found to significantly affect the kinetic parameters of the process. 相似文献
83.
Nadezhda V. Vasilieva Irina G. Irtegova Nina P. Gritsan Anton V. Lonchakov Alexander Yu. Makarov Leonid A. Shundrin Andrey V. Zibarev 《Journal of Physical Organic Chemistry》2010,23(6):536-543
In comparison with 2,1,3‐benzothia(selena)diazoles, electrochemical oxidation and reduction of their 4,5,6,7‐tetrafluoro derivatives and a number of related compounds were studied by cyclic voltammetry. For nine examples of this class, the first reduction peaks are reversible and corresponding radical anions (RAs) are long‐lived at 295 K in MeCN and especially in DMF. The oxidation peaks were irreversible and corresponding radical cations were not observed. Electrochemically generated RAs were characterized by EPR measurements and DFT calculations at the UB3LYP/6‐31+G(d) level. The spin density distribution in the RAs is analyzed in connection with effects of S substitution by Se and/or H by F. The prospects of the studied RAs in the design and synthesis of magnetically active materials are discussed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
84.
Maxim V. Shugaev Nadezhda M. Bulgakova 《Applied Physics A: Materials Science & Processing》2010,98(1):103-109
On the basis of a two-temperature model taking into account the laser-generated stress waves, we have performed an analysis
of heating and melting dynamics in different metallic films (Au, Zn, Cr) irradiated by femtosecond laser pulses for the experimental
conditions on laser-induced forward transfer. The modeling results have allowed puzzling out why, even within the same family
of materials, substances can be transferred in the different phase states under rather similar laser-irradiation conditions. 相似文献
85.
Olga A. Bulgakova Nadezhda M. Bulgakova Vladimir P. Zhukov 《Applied Physics A: Materials Science & Processing》2010,101(1):53-59
We report a model of nanosecond laser ablation of compound semiconductors taking into account stoichiometry loss as a result
of different volatilities of the material components. The model is based on the heat-flow equation for the bulk material and
the diffusion equation for its atomic constituents and takes into account variations of material properties as functions of
temperature and composition. Changing the optical response which results from stoichiometry violation is described within
the concept of an effective medium and a multi-layer reflection model is applied. For cadmium telluride, as an example, the
processes of ablation, melting, and resolidification under the action of a KrF laser have been studied in dynamics for particular
experimental conditions in a wide range of laser fluences from the ablation threshold to the plasma shielding regimes described
by the effective plasma plume representation. Multi-shot irradiation regimes have been investigated and the mechanism of the
irradiation-controlled stoichiometry reversal has been elucidated. 相似文献
86.
Chechina Nataliia V. Kolos Nadezhda N. Omelchenko Irina V. 《Chemistry of Heterocyclic Compounds》2019,55(12):1190-1196
Chemistry of Heterocyclic Compounds - A series of novel fused pyrrole derivatives was synthesized by one-pot three-component reaction of β-enaminoketones, derived from cyclohexane-1,3-dione or... 相似文献
87.
Timur M. Galiullin Nadezhda V. Pokhvishcheva Andrey V. Kalinichev Maria A. Peshkova 《Electroanalysis》2019,31(9):1708-1718
In this paper we report on the novel polymeric membranes for the liquid junction‐free reference electrodes. The membranes contain the ionic liquids (ILs) based on the amino acid anions, namely valine‐, leucine‐, lysine‐ and histidine‐anions, and 1‐butyl‐3‐methylimidazolium cation. Addition of the ILs, and especially of the valine‐based one, to the polymeric plasticized membranes allows significant stabilization of the electrode potential and makes it insensitive to the solution composition. A simple criterion based on the calculated lipophilicities of the cation and anion of the IL is proposed for a priori estimation of its applicability for potential stabilization. The addition of the IL as a microcomponent is found to be advantageous over plasticizing the membrane with the IL due to better potential stability, higher dissociation degree and mobility of the species. The resistance of the novel reference membranes can be tuned by addition of the lipophilic membrane electrolytes, e. g. ETH500. The applicability of the developed reference electrodes is verified in the potentiometric calibration of the indicator K+‐ and Ca2+‐selective electrodes. Implementation of the amino acid‐based ionic liquids with low environmental toxicity can make a significant contribution to the development of nature‐friendly potentiometry. 相似文献
88.
89.
Mesomorphic properties and structures of two mix-substituted lipophilic phthalocyanine derivatives of the A3B type, with a different ratio of electron-donating (hexadecyloxy-) and electron-withdrawing (Cl-) substituents on the isoindol fragments ‘A’ and ‘B’, correspondingly, were studied by polarising optical microscopy, differential scanning calorimetry and small-angle X-ray scattering. Both compounds display columnar mesophases, and the type of organisation of the columns in the mesomorphic state was found to strongly depend on the number of peripheral chlorine substituents in the molecule. The di-chloro-substituted phthalocyanine forms a solid pasty lamellar phase at room temperature, which on heating undergoes successive transitions to two large-lattice columnar mesophases (2D-Colh and 3D-MCol) arising from the aggregation of several phthalocyanine-containing piles. On the contrary, aggregation of columns does not occur for the tetra-chloro-substituted phthalocyanine, which forms a nematic columnar mesophase of single phthalocyanine piles (1D-NCol). While the di-chloro-compound partly crystallises on cooling, the nematic phase of the tetra-chloro-compound freezes at room temperature. The reasons for this different self-organisation behaviour are not yet fully understood, but some hints may be deduced from the proposed supramolecular models. 相似文献
90.