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951.
G. Jeremy Leong Maxwell C. Schulze Matthew B Strand David Maloney Sarah L. Frisco Huyen N. Dinh Bryan Pivovar Ryan M. Richards 《应用有机金属化学》2014,28(1):1-17
Platinum‐based catalytic materials have received significant attention, particularly in the shape and size control of faceted materials for catalysis. More recently, there has been a rapid increase in the number of reports of successful preparations in this field; however, a fundamental understanding of controlled growth towards catalytic material design is essential for future implementation and broad application. In this review, we provide an overview of the recent findings reported since 2009, focusing on methods for shape control as well as the effects of exposed surface facets on select catalytic reactions. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
952.
953.
Prof. Richard D. Adams Dr. Poonam Dhull Matthew Pennachio Prof. Marina A. Petrukhina Dr. Mark D. Smith 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(16):4234-4239
The reaction of Re2(CO)8(μ-C6H5)(μ-H), 1 with corannulene (C20H10) yielded the product Re2(CO)8(μ-H)(μ-η2-1,2-C20H9), 2 (65 % yield) containing a Re2 metalated corannulene ligand formed by loss of benzene from 1 and the activation of one of the CH bonds of the nonplanar corannulene molecule by an oxidative-addition to 1 . The corannulenyl ligand has adopted a bridging η2-σ+π coordination to the Re2(CO)8 grouping. Compound 2 reacts with a second equivalent of 1 to yield three isomeric doubly metalated corannulene products: Re2(CO)8(μ-H)(μ-η2-1,2-μ-η2-10,11-C20H8)Re2(CO)8(μ-H), 3 (35 % yield), Re2(CO)8(μ-H)(μ-η2-2,1-μ-η2-10,11-C20H8)Re2(CO)8(μ-H), 4 (12 % yield), and Re2(CO)8(μ-H)(μ-η2-1,2-μ-η2-11,10-C20H8)Re2(CO)8(μ-H), 5 (12 % yield), by a second CH activation on a second rim double bond on the corannulene molecule. The isomers differ by the relative orientations of the coordinated Re2(CO)8(μ-H) groupings. All new products were characterized structurally by single crystal X-ray diffraction analysis. 相似文献
954.
955.
Dr. James Jennings Dr. Erik J. Cornel Dr. Matthew J. Derry Dr. Deborah L. Beattie Dr. Matthew J. Rymaruk Oliver J. Deane Prof. Anthony J. Ryan Prof. Steven P. Armes 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(27):10940-10945
Polymerization-induced self-assembly (PISA) enables the scalable synthesis of functional block copolymer nanoparticles with various morphologies. Herein we exploit this versatile technique to produce so-called “high χ–low N” diblock copolymers that undergo nanoscale phase separation in the solid state to produce sub-10 nm surface features. By varying the degree of polymerization of the stabilizer and core-forming blocks, PISA provides rapid access to a wide range of diblock copolymers, and enables fundamental thermodynamic parameters to be determined. In addition, the pre-organization of copolymer chains within sterically-stabilized nanoparticles that occurs during PISA leads to enhanced phase separation relative to that achieved using solution-cast molecularly-dissolved copolymer chains. 相似文献
956.
Dr. Jin Lu Hesam Mazidi Tianben Ding Oumeng Zhang Prof. Matthew D. Lew 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(40):17725-17732
In soft matter, thermal energy causes molecules to continuously translate and rotate, even in crowded environments, thereby impacting the spatial organization and function of most molecular assemblies, such as lipid membranes. Directly measuring the orientation and spatial organization of large collections (>3000 molecules μm−2) of single molecules with nanoscale resolution remains elusive. In this paper, we utilize SMOLM, single-molecule orientation localization microscopy, to directly measure the orientation spectra (3D orientation plus “wobble”) of lipophilic probes transiently bound to lipid membranes, revealing that Nile red's (NR) orientation spectra are extremely sensitive to membrane chemical composition. SMOLM images resolve nanodomains and enzyme-induced compositional heterogeneity within membranes, where NR within liquid-ordered vs. liquid-disordered domains shows a ≈4° difference in polar angle and a ≈0.3π sr difference in wobble angle. As a new type of imaging spectroscopy, SMOLM exposes the organizational and functional dynamics of lipid-lipid, lipid-protein, and lipid-dye interactions with single-molecule, nanoscale resolution. 相似文献
957.
958.
Toward Functional Type III [Fe]‐Hydrogenase Biomimics for H2 Activation: Insights from Computation
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Kevin A. Murray Dr. Matthew D. Wodrich Prof. Dr. Xile Hu Prof. Dr. Clémence Corminboeuf 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(10):3987-3996
The chemistry of [Fe]‐hydrogenase has attracted significant interest due to its ability to activate molecular hydrogen. The intriguing properties of this enzyme have prompted the synthesis of numerous small molecule mimics aimed at activating H2. Despite considerable effort, a majority of these compounds remain nonfunctional for hydrogenation reactions. By using a recently synthesized model as an entry point, seven biomimetic complexes have been examined through DFT computations to probe the influence of ligand environment on the ability of a mimic to bind and split H2. One mimic, featuring a bidentate diphosphine group incorporating an internal nitrogen base, was found to have particularly attractive energetics, prompting a study of the role played by the proton/hydride acceptor necessary to complete the catalytic cycle. Computations revealed an experimentally accessible energetic pathway involving a benzaldehyde proton/hydride acceptor and the most promising catalyst. 相似文献
959.
Tristan Butler Sasha E. Alden Madeleine Taylor Stephen Deese David A. Rider Matthew Laskoski 《Journal of polymer science. Part A, Polymer chemistry》2018,56(23):2630-2640
Blended resins were prepared from the resorcinol-based PEEK-like oligomeric phthalonitrile resin (RES) and tetrakis(phenylethynyl)benzene (TPEB), a high char yield arylacetylene resin. Initial probing of curing properties using differential scanning calorimetry, indicated that TPEB and RES co-cure when heated. Characterization of thermal properties using thermogravimetric analysis indicated that a 1:1 TPEB-RES blend (by weight) exhibited a char yield of 80% which was 6% larger compared to pure RES (74%). According to FTIR characterization, the enhanced thermal properties of TPEB-RES were the result of increased crosslinking density. Rheological studies of TPEB, RES, and TPEB-RES blends indicated that blended systems exhibit similar processing characteristics as RES resin. For example, resins display ideal viscosities and relatively large processing windows when cured at 175 °C. Alternatively, pure TPEB resin exhibits low viscosities when melted, which are not suitable for preparing composite materials. This study indicates that preparing TPEB-RES blends is an effect strategy for improving thermal performance of potential RES composites while still maintaining the required processability for fabrication of dense polymer composites. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 2630–2640 相似文献
960.
We leverage the results of the prequel [8], in combination with a theorem of D. Orlov to create a categorical covering picture for factorizations. As applications, we provide a conjectural geometric framework to further understand M. Kontsevich's Homological Mirror Symmetry conjecture and obtain new cases of a conjecture of Orlov concerning the Rouquier dimension of the bounded derived category of coherent sheaves on a smooth variety. 相似文献