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121.
122.
Qijun Meng Biaobiao Zhang Lizhou Fan Haidong Liu Mario Valvo Kristina Edstrm Maria Cuartero Roland de Marco Gaston A. Crespo Licheng Sun 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(52):19203-19209
Water‐splitting photoanodes based on semiconductor materials typically require a dopant in the structure and co‐catalysts on the surface to overcome the problems of charge recombination and high catalytic barrier. Unlike these conventional strategies, a simple treatment is reported that involves soaking a sample of pristine BiVO4 in a borate buffer solution. This modifies the catalytic local environment of BiVO4 by the introduction of a borate moiety at the molecular level. The self‐anchored borate plays the role of a passivator in reducing the surface charge recombination as well as that of a ligand in modifying the catalytic site to facilitate faster water oxidation. The modified BiVO4 photoanode, without typical doping or catalyst modification, achieved a photocurrent density of 3.5 mA cm?2 at 1.23 V and a cathodically shifted onset potential of 250 mV. This work provides an extremely simple method to improve the intrinsic photoelectrochemical performance of BiVO4 photoanodes. 相似文献
123.
Recent Approaches to Design Electrocatalysts Based on Metal–Organic Frameworks and Their Derivatives
Juan Liu Shujin Hou Weijin Li Aliaksandr S. Bandarenka Roland A. Fischer 《化学:亚洲杂志》2019,14(20):3474-3501
Rational design and synthesis of efficient electrocatalysts are important constituents in addressing the currently growing provision issues. Typical reactions, which are important to catalyze in this respect, include CO2 reduction, the hydrogen and oxygen evolution reactions as well as the oxygen reduction reaction. The most efficient catalysts known up‐to‐date for these processes usually contain expensive and scarce elements, substantially impeding implementation of such electrocatalysts at a larger scale. Metal‐organic frameworks (MOFs) and their derivatives containing affordable components and building blocks, as an emerging class of porous functional materials, have been recently attracting a great attention thanks to their tunable structure and composition together with high surface area, just to name a few. Up to now, several MOFs and MOF‐derivatives have been reported as electrode materials for the energy‐related electrocatalytic application. In this review article, we summarize and analyze current approaches to design such materials. The design strategies to improve the Faradaic efficiency and selectivity of these catalysts are discussed. Last but not least, we discuss some novel strategies to enhance the conductivity, chemical stability and efficiency of MOF‐derived electrocatalysts. 相似文献
124.
Corentin Boilleau Nicolas Suaud Roland Bastardis Nathalie Guihéry Jean Paul Malrieu 《Theoretical chemistry accounts》2010,126(3-4):231-241
DFT calculations are performed on a model mixed-valence system presenting a double exchange phenomenon. Due to the intrinsic multireference character of the lowest Ms components of the spin states, it is shown that the interactions involved in the double-exchange model cannot be simply extracted from the DFT energies as it is sometimes done. It is, however, possible to extract from different DFT single determinant energies the interactions of a generalized Hubbard Hamiltonian, from which, in a second step, the double-exchange spectrum may be evaluated. The problems generated by the charge and spin polarization are discussed in both symmetric and non symmetric geometries, and the sensitivity of the results to the choice of the density functional is illustrated. 相似文献
125.
126.
Günter Reck Roland Becker 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(3):m134-m136
Bis(N,N‐di‐n‐butyldithiocarbamato‐κ2S,S′)(1,10‐phenanthroline‐κ2N,N′)zinc(II) ethanol hemisolvate, [Zn(C9H18NS2)2(C12H8N2)]·0.5C2H6O, (I), and bis(N,N‐di‐n‐hexyldithiocarbamato‐κ2S,S′)bis(1,10‐phenanthroline‐κ2N,N′)calcium(II), [Ca(C13H26NS2)2(C12H8N2)2], (II), are mixed‐ligand complexes. In the first compound, the Zn atom has a distorted octahedral coordination, while in the second compound, the Ca atom is eight‐coordinate, with four S and four N atoms forming a highly distorted cube. 相似文献
127.
C. Malla Reddy Ashwini Nangia Ram K. R. Jetti Roland Boese 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):o331-o333
The crystal structure of the title compound, alternatively called 1,2,3‐triiodo‐5‐(triphenylmethyl)benzene, C25H17I3, is analysed in terms of I⋯I and I⋯π interactions and the herring‐bone T motif between phenyl groups. There are two molecules in the asymmetric unit, denoted A and B. Inversion‐related A molecules are connected via an I⋯π interaction (3.641 Å, to a C—C bond mid‐point) to form an I⋯π dimer, and these dimers are connected through symmetry‐independent B molecules via I⋯I [3.5571 (15) Å] and I⋯π (3.561 Å, to a C—C bond mid‐point) interactions. 相似文献
128.
Winter B Ivanco J Netzer FP Ramsey MG Salzmann I Resel R 《Langmuir : the ACS journal of surfaces and colloids》2004,20(18):7512-7516
A combination of in situ surface sensitive-techniques, UV photoemission and low energy electron diffraction, with ex situ bulk sensitive X-ray diffraction reveals the formation of epitaxial thin films of sexiphenyl on Al(111) starting from the first monolayer. For room temperature growth, highly ordered films are formed with a unique alignment of the sexiphenyl molecules with the long axes of all molecules aligned parallel to both the surface and the <10> azimuthal directions of Al(111). This is related to a densely packed highly commensurate first monolayer, which acts as a template for the unique (21) crystallite orientation observed. 相似文献
129.
Hill M Erker G Kehr G Fröhlich R Kataeva O 《Journal of the American Chemical Society》2004,126(35):11046-11057
The dimethylsilanediyl-bridged ansa-zirconocene dichloride 1, that contains a pendent allyl substituent at a Cp-ring, adds HB(C(6)F(5))(2) to the vinyl group to yield the bifunctional zirconocene/borane complex 2. Substituted benzimidazoles were added to the strongly electrophilic borane moiety as protective groups, which allowed subsequent chloride versus -CH(2)SiMe(3) exchange at zirconium to take place by treatment with the respective alkyllithium reagent. Alternatively, the introduction of active sigma-ligands at zirconium is carried out first, followed by the hydroboration reaction. This route was followed for the synthesis of the diphenyl-ansa-zirconocene/borane complex 12. Complex 12 reacts slowly in solution by intramolecular electrophilic attack of the borane at its adjacent Cp-ring, followed by deprotonation using a [Zr]-Ph group to yield the zwitterionic complex 14 featuring a borata-tetrahydroindenyl moiety as part of the ansa-metallocene framework. Complex 14 was characterized by X-ray diffraction. It adds PMe(3) at zirconium to yield 15. Thermolysis of 12 with excess PMe(3) leads to the formation of the (aryne)zirconocene complex 18, which is stabilized by PMe(3) coordination to zirconium and PMe(3) addition to boron. N-Methylbenzimidazole adds to the -B(C(6)F(5))(2) unit of 12 to give the 1:1 adduct 19. Thermolysis of 19 at 80 degrees C in benzene solution in the presence of one additional equivalent of N-methylbenzimidazole results in deprotonation of the substrate to yield the sigma-N-methylbenzimidazolyl zirconium complex 20 (as a mixture of two diastereoisomers). An additional N-methylbenzimidazole ligand is bonded to the B(C(6)F(5))(2) unit in this product. 相似文献
130.