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141.
Inside Back Cover: Copper–Organic Framework Fabricated with CuS Nanoparticles: Synthesis,Electrical Conductivity,and Electrocatalytic Activities for Oxygen Reduction Reaction (Angew. Chem. Int. Ed. 49/2016) 下载免费PDF全文
Keumnam Cho Prof. Sung‐Hwan Han Prof. Myunghyun Paik Suh 《Angewandte Chemie (International ed. in English)》2016,55(49):15443-15443
142.
Min Jeong Hyun Mi Shin Yong Jin Kim Young-Woong Suh 《Research on Chemical Intermediates》2016,42(1):57-70
In catalytic decomposition of dimethylhexane-1,6-dicarbamate (HDC) into hexamethylene-1,6-diisocyanate (HDI), Zn-containing homogeneous (i.e., zinc acetate) and heterogeneous (i.e., ZnO) catalysts were active among a number of catalysts tested, due to the great electron withdrawing ability of Zn ions. Particularly, when polyethylene glycol dimethyl ether was used as a solvent, ZnO was found to be relatively robust, because the catalytic performance was maintained up to the third use (HDC conversion of 93 % and HDI yield of 67 % at 180 °C for 1 h). Through investigation of a HDC/ZnO mixture at elevated temperatures by IR spectroscopy, a possible reaction scheme of ZnO-catalyzed decomposition of HDC was proposed. The H atom is removed from the N–H group of HDC by hydrogen bonding with an O site on the ZnO surface, followed by coordination of an O–C=O group in monodentate mode to a Zn site. The C–O group in the O–C=O linkage is then cleaved yielding the isocyanate and surface methoxide species. Finally, methanol is released from ZnO by a reaction between the surface methoxide and the hydroxyl species. 相似文献
143.
The object of the present paper is to study weakly cyclic Z symmetric spacetimes. At first we prove that a weakly cyclic Z symmetric spacetime is a quasi Einstein spacetime. Then we study \({{(WCZS)}_{4}}\) spacetimes satisfying the condition div \({C=0}\). Next we consider conformally flat \({{(WCZS)}_{4}}\) spacetimes. Finally, we characterise dust fluid and viscous fluid \({{(WCZS)}_{4}}\) spacetimes. 相似文献
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146.
A 3D porous metal-organic framework [Zn3(ntb)2(EtOH)2]n.4nEtOH (1) that generates 1D channels of honeycomb aperture has been prepared by the solvothermal reaction of Zn(NO3)(2).6 H2O and 4,4',4'-nitrilotrisbenzoic acid (H3NTB) in EtOH at 110 degrees C. Framework 1 exhibits reversible single-crystal-to-single-crystal transformations upon removal and rebinding of the coordinating EtOH as well as the EtOH guest molecules, which give rise to desolvated crystal [Zn3(ntb)2]n (1') and resolvated crystal [Zn3(ntb)2-(EtOH)2]n.4nEtOH (1'). The X-ray structures indicate that 3D host framework is retained during the transformations from 1 to 1' and from 1' to 1', but the coordination geometry of ZnII ions changes from/to trigonal bipyramid to/from tetrahedron, concomitant with the rotational rearrangement of a carboxylate plane of the NTB3- relative to its associated phenyl ring. To retain the single crystal integrity, extensive cooperative motions must exist between the molecular components throughout the crystal. Framework 1' exhibits permanent porosity, thermal stability up to 400 degrees C, and blue luminescence, and high storage capabilities for N2, H2, CO2, and CH4. 相似文献
147.
Seo SY Jung JW Jung JK Kim NJ Chin YW Kim J Suh YG 《The Journal of organic chemistry》2007,72(2):666-668
Rodgersinol was synthesized via seven linear steps in 31% overall yield, and the absolute configuration of the C-10 stereogenic center was elucidated. The key feature of the synthesis involves the efficient Cu(II)-mediated coupling of two aromatic moieties for the diaryl ether intermediate and the enantioselective construction of the hydroxypropyl substituent by a regio- and stereoselective methyl addition to the chiral aryloxiranes in an inversion manner. 相似文献
148.
Novel fully π‐conjugated poly(arylene ethynylene)s 1 and 2 having diphenylmaleimides in the backbone were prepared utilizing a Pd(0)‐Cu(I) catalyzed coupling reaction (Sonogashira method) of N‐alkyl substituted 1,2‐di(4‐bromophenyl) maleimides ( 5 and 6 ) with 1,4‐diethynylbenzene. Whereas polymer 1 with an N‐hexyl side chain showed low solubility, 2 having an N‐ dodecyl group was completely soluble in common organic solvents. Determined by GPC, M̄w of 2 was 45 800 Da with a polydispersity index of 2.5. Polymer 2 showed UV‐visible absorption maxima at 330 nm and 413 nm and greenish yellow fluorescence with a maximum of 530 nm. 相似文献
149.
Jung‐Bae Jun Jin‐Woong Kim Joon‐Woo Lee Kyung‐Do Suh 《Macromolecular rapid communications》2001,22(12):937-940
A new method to synthesize uniform polyaniline‐coated composite microparticles was contrived considering the surface reactivity and porous structure of substrate polymer particles. It was found that the pore diameter together with the epoxy functional group plays a crucial role in controlling the structure of polyaniline shell. The polyaniline composite particles produced in this study are believed to find great applicability in piezoelectronics and as electro‐rheological fluids. 相似文献
150.
Sang‐Wook Park Seung‐Hyeun Park Wonho Kim Dong‐Soo Suh In‐Joe Sohn 《Journal of polymer science. Part A, Polymer chemistry》2000,38(19):3543-3549
The phase‐transfer catalyzed graft copolymerization of methyl methacrylate onto polychloroprene was carried out using tricaprylylmethylammonium chloride as a phase‐transfer catalyst in a two‐phase system of an aqueous Na2S2O8 solution and toluene at 55 °C under a nitrogen atmosphere. The initial rate of graft copolymerization was expressed as the combined terms of quaternary onium cation and peroxydisulfate anion in the aqueous phase rather than the fed concentrations of catalyst and Na2S2O8. The observed initial rate of graft copolymerization was used to analyze the graft copolymerization mechanism with a cycle phase‐transfer initiation step in the heterogeneous liquid–liquid system. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3543–3549, 2000 相似文献