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971.
Qihong Chen Delin Chu Roger C.E. Tan 《Nonlinear Analysis: Real World Applications》2011,12(3):1459-1474
This paper is devoted to the state-constrained optimal control problem of evolutionary variational inequality. In this paper, the control domain is not necessarily convex. Moreover, since our state constraint is quite general and, in many cases, it requires pointwise behavior of the state, the framework of the partial differential equation (instead of the abstract framework) is used. Some optimality conditions (in the form of Pontryagin’s principle) for optimal controls are established. 相似文献
972.
973.
974.
Feriel Necibi Saida Ben Salah Julien Roger Jean-Cyrille Hierso Taoufik Boubaker 《国际化学动力学杂志》2020,52(10):669-680
The kinetics of the reactions of 4-nitrobenzofurazane 1a , 4-nitrobenzothiadiazole 1b , and 4-nitrobenzoselenadiazole 1c with a series of 4-Y-substituted phenoxide anions 2a-e (Y = OMe, Me, H, Cl, and CN) in aqueous solution at 20°C were investigated photometrically. The derived second-order rate constants (k2) have been combined with the nucleophilicity parameters values of these series of anions 2a-e to determine the electrophilicity parameters E of electrophiles 1a-c according to the linear free-energy relationship (log k2)/s versus N. General reactivity of these electrophiles 1a-c is found to be fairly similar with E values ranging in −10.77 ± 0.61 < E < −7.53 ± 0.29. The comparison with structurally related neutral electron-deficient heteroaromatic and aromatic compounds revealed that 1a - c are more reactive than 1,3,5-trinitrobenzene, as benchmark aromatic electrophile used in nucleophilic addition or substitution processes. The rate constants for the reactions of 4-nitrobenzochalcogenadiazoles 1a-c with some other nucleophiles were measured and found to agree with those calculated from Mayr's equation. Finally, analysis of the rate data in terms of the Brønsted approach reveals that 1a-c exhibits especially low intrinsic reactivity in σ-adducts 3 forming reactions. 相似文献
975.
976.
Roeland De Borger Alain Collas Roger Dommisse Frank Blockhuys 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(1):o50-o54
Three substituted triphenyl(phenylimino)phosphoranes, namely (4‐cyanophenylimino)triphenylphosphorane, C25H19N2P, (I), (4‐nitrophenylimino)triphenylphosphorane, C24H19N2O2P, (II), and (3‐nitrophenylimino)triphenylphosphorane, C24H19N2O2P, (III), were synthesized as precursors for the preparation of substituted diphenylcarbodiimides. All three compounds display a supramolecular arrangement in which the substituted benzene rings are organized in an antiparallel fashion. The nitro group on the ring participates in C—H...O and O...π interactions, forming intermolecular dimers. Compound (III) shows disorder which involves the rotation of one of the phenyl rings of the triphenylphosphine group. 相似文献
977.
978.
Charles Ng Xiangju Kong Dr. Dongxia Wu Dr. Min Song Dr. Xiaohong Shi Xiaochun Xu Wei‐Han OuYang Rongxian He Prof. Xing‐Zhong Zhao Tom Lee Prof. F. Charles Brunicardi Dr. Mitch André Garcia Prof. Antoni Ribas Prof. Roger S. Lo Prof. Hsian‐Rong Tseng 《Angewandte Chemie (International ed. in English)》2013,52(12):3379-3383
979.
Synthesis,structural and chemosensitivity studies of arene d6 metal complexes having N‐phenyl‐N´‐(pyridyl/pyrimidyl)thiourea derivatives
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Sanjay Adhikari Omar Hussain Roger M. Phillips Werner Kaminsky Mohan Rao Kollipara 《应用有机金属化学》2018,32(6)
The d6 metal complexes of thiourea derivatives were synthesized to investigate its cytotoxicity. Treatment of various N‐phenyl‐N´ pyridyl/pyrimidyl thiourea ligands with half‐sandwich d6 metal precursors yielded a series of cationic complexes. Reactions of ligand (L1‐L3) with [(p‐cymene)RuCl2]2 and [Cp*MCl2]2 (M = Rh/Ir) led to the formation of a series of cationic complexes bearing general formula [(arene)M(L1)к2(N,S)Cl]+, [(arene)M(L2)к2(N,S)Cl]+ and [(arene)M(L3)к2(N,S)Cl]+ [arene = p‐cymene, M = Ru ( 1 , 4 , 7 ); Cp*, M = Rh ( 2 , 5 , 8 ); Cp*, Ir ( 3 , 6 , 9 )]. These compounds were isolated as their chloride salts. X‐ray crystallographic studies of the complexes revealed the coordination of the ligands to the metal in a bidentate chelating N,S‐ manner. Further the cytotoxicity studies of the thiourea derivatives and its complexes evaluated against HCT‐116 (human colorectal cancer), MIA‐PaCa‐2 (human pancreatic cancer) and ARPE‐19 (non‐cancer retinal epithelium) cancer cell lines showed that the thiourea ligands displayed no activity. Upon complexation however, the metal compounds possesses cytotoxicity and whilst potency is less than cisplatin, several complexes exhibited greater selectivity for HCT‐116 or MIA‐PaCa‐2 cells compared to ARPE‐19 cells than cisplatin in vitro. Rhodium complexes of thiourea derivatives were found to be more potent as compared to ruthenium and iridium complexes. 相似文献
980.
Guy Guerch Jean-Francois Labarre Roger Lahana Gaston Levy Francois Sournies 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-3):333-336
Abstract Aziridinocyclophosphazenes N3P3Az6 (code name MYKO 63), N4P4Az8 (code name MYKO 83) and relatives constituted the first generation of anticancer drugs whose efficiency on several rodent neoplasms was made conspicuous in a quantitative manner from 1976 to 1978 both in our Laboratory and by EORTC Screening Pharmacology Groups1. MYKO 63 appeared at that time as a promising drug for industrial development owing to its wide spectrum of activity and its very low mutagenicity2. However, this hope failed as a consequence of a cumulative toxicity which occurs upon heavy polyinjections schedules. In other words, MYKO 63 exhibits an uncomfortable kinetics of action on the tumor - and, consequently, of excretion - presumably due (it was our assumption) to a too high chemical stability of the molecule. 相似文献