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181.
Kira J. Weissman Cameron J. Smith Ulf Hanefeld Ranjana Aggarwal Matthew Bycroft James Staunton Peter F. Leadlay 《Angewandte Chemie (International ed. in English)》1998,37(10):1437-1440
The production of genetically engineered polyketides depends critically on thioesterase activity for product release. In vitro studies with the thioesterase from the erythromycin polyketide synthase (PKS) have demonstrated that the ability of this enzyme to act as a universal decoupler is limited, but stereochemical variation is readily tolerated. Synthetic analogues with all four stereochemical configurations of the natural substrate's 2-methyl-3-hydroxy substitution pattern ( 1 – 4 ; X=p-nitrophenoxy) were substrates for the enzyme. 相似文献
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Modular Bidentate Hybrid NHC‐Thioether Ligands for the Stabilization of Palladium Nanoparticles in Various Solvents 下载免费PDF全文
Andreas Rühling Kira Schaepe Lena Rakers Benjamin Vonhören Patricia Tegeder Prof. Dr. Bart Jan Ravoo Prof. Dr. Frank Glorius 《Angewandte Chemie (International ed. in English)》2016,55(19):5856-5860
The synthesis of four different bidentate hybrid NHC‐thioether ligands is presented. The corresponding palladium nanoparticles are stable in various solvents, depending on the ligand used, and show high chemoselectivity in the hydrogenation of olefins. The solubility of the nanoparticles can be switched multiple times depending on the pH value of the solvent. XPS analysis (which shows a subtle shift in the binding energy) was identified as a convenient tool to establish the binding mode of NHC ligands. 相似文献
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Dr. Liliang Wang Jian Xu Prof. Mitsuo Kira Liping Yan Dr. Xu-Qiong Xiao Prof. Zhifang Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(5):1996-2000
A cyclic (R2SnAu)3 anion ( 3− , R2Sn=2,2,5,5-tetrakis(trimethylsilyl)-1-stannacyclopentane-1,1-diyl) has been synthesized as a stable blue salt with K+(THF)6 through the reaction of stable dialkylstannylene 1 with R′3PAuCl (R′=Et, Ph) followed by the reduction with KC8. Crystallographic and NMR analysis shows that the six-membered (SnAu)3 ring of 3− is planar and highly symmetric with an equal distance of six Au−Sn bonds. A UV/Vis spectrum of 3− in hexane reveals an intense absorption maximum at 598 nm. While cyclic Au3− with four valence electrons is known as unstable anti-aromatic anion, 3− with three divalent tin ligands is stable σ aromatic anion with an unprecedented Möbius orbital array as predicted by the perturbation MO and CCSD analysis of 3− . 相似文献
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Xavier Fradera Andreas Verras Yuan Hu Deping Wang Hongwu Wang James I. Fells Kira A. Armacost Alejandro Crespo Brad Sherborne Huijun Wang Zhengwei Peng Ying-Duo Gao 《Journal of computer-aided molecular design》2018,32(1):113-127
We describe the performance of multiple pose prediction methods for the D3R 2016 Grand Challenge. The pose prediction challenge includes 36 ligands, which represent 4 chemotypes and some miscellaneous structures against the FXR ligand binding domain. In this study we use a mix of fully automated methods as well as human-guided methods with considerations of both the challenge data and publicly available data. The methods include ensemble docking, colony entropy pose prediction, target selection by molecular similarity, molecular dynamics guided pose refinement, and pose selection by visual inspection. We evaluated the success of our predictions by method, chemotype, and relevance of publicly available data. For the overall data set, ensemble docking, visual inspection, and molecular dynamics guided pose prediction performed the best with overall mean RMSDs of 2.4, 2.2, and 2.2 Å respectively. For several individual challenge molecules, the best performing method is evaluated in light of that particular ligand. We also describe the protein, ligand, and public information data preparations that are typical of our binding mode prediction workflow. 相似文献
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Ramona Abele Liga Zvejniece Edgars Abele Kira Rubina Pavel Arsenyan Marina Vandish Olga Pudova Maija Dambrova Ilona Domracheva Irina Shestakova Juris Popelis Edmunds Lukevics 《应用有机金属化学》2004,18(4):181-186
New silicon derivatives of hetaryl propargyl sulfides and propargyl alcohols were synthesized using phase‐transfer catalytic and organometallic methods. These compounds were tested for acute toxicity and neurotropic activity in the pentylenetetrazole test, and for phenamine hypothermia, phenamine hyperactivity and passive avoidance response tests. We have found that the silyl propargyl alcohols and sulfides are low toxicity compounds, the LD50 being 700–1300 mg kg?1. In the PAR test, the synthesized compounds exerted some memory‐improving activity. For di‐1‐(3‐methyl‐3‐hydroxybutyn‐1‐yl)methyl(3‐iodopropyl)silane ( 16 ) the effect was statistically significant and amounted to 250% of the control level. In the pentylenetetrazole test, all compounds possessed anticonvulsant activity, the most active compounds being 3‐(benzoxazolylthio)‐1‐propynyl(trimethyl)silane ( 6 ) and di‐[2‐(1‐hydroxycyclohexyl)ethynyl]methyl(3‐iodopropyl)silane ( 17 ). The phenamine‐induced hyperactivity was significantly elevated after treatment with (3‐trimethylsilyl‐2‐propynyl)thiobenzene ( 1 ) or di‐[1‐(3‐methyl‐3‐hydroxybutyn‐1‐yl)diphenylsilane ( 12 ). Our data show that these silicon derivatives of hetaryl propargyl sulfides and propargyl alcohols possess certain memory improving and anticonvulsant activity that should be studied in detail to evaluate the receptor systems involved. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献