全文获取类型
收费全文 | 327篇 |
免费 | 7篇 |
专业分类
化学 | 304篇 |
晶体学 | 1篇 |
物理学 | 29篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2019年 | 15篇 |
2018年 | 10篇 |
2017年 | 1篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 3篇 |
2013年 | 19篇 |
2012年 | 13篇 |
2011年 | 16篇 |
2010年 | 9篇 |
2009年 | 32篇 |
2008年 | 23篇 |
2007年 | 20篇 |
2006年 | 26篇 |
2005年 | 24篇 |
2004年 | 23篇 |
2003年 | 17篇 |
2002年 | 13篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 2篇 |
1998年 | 7篇 |
1997年 | 3篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1941年 | 1篇 |
排序方式: 共有334条查询结果,搜索用时 368 毫秒
91.
92.
A. V. Samet K. A. Kislyi V. N. Marshalkin Yu. A. Strelenko Yu. V. Nelyubina K. A. Lyssenko V. V. Semenova 《Russian Chemical Bulletin》2007,56(10):2089-2093
1,3-Dinitro[b, f][1,4]dibenzoxazepin-11(10H)-one enters nucleophilic substitution reactions with N-nucleophiles, azide ion preferably replacing the nitro group in position
3, whereas amines the one in position 1. Structures of the substitution products were confirmed by X-ray diffraction and 1H NMR NOE spectroscopy. The selectivity observed in the reaction with amines was supposed to be caused by the stabilization
of the intermediate σ-complex with the NH…O intramolecular hydrogen bond.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2018–2022, October, 2007. 相似文献
93.
94.
95.
A. B. Zachernyuk A. P. Pleshkova K. A. Lyssenko M. V. Nevezhin A. M. Muzafarov 《Russian Chemical Bulletin》2010,59(2):374-381
A difunctional dendron composed of three spiro-linked cyclosiloxane fragments was synthesized by a convergent way. This is of interest for the preparation of cylindrical and spherical dendritic molecules with the inorganic siloxane core and peripheral organic layer. The structures of the dendron synthesized and intermediates containing the Si-Cl, Si-H, Si-OH groups were confirmed by data from mass-spectrometry and X-ray diffraction. 相似文献
96.
Berestovitskaya V. M. Makarenko S. V. Bushmarinov I. S. Lyssenko K. A. Smirnov A. S. Stukan’ E. V. 《Russian Chemical Bulletin》2009,58(5):1023-1033
A two-step method was developed for the synthesis of new polyfunctional aziridines involving the addition of aromatic amines
to 1-bromo-3,3,3-trichloro-1-nitropropene and the dehydrobromination of the resulting adducts. The 1H and 13C NMR spectroscopic and X-ray diffraction studies showed that 1-aryl-2-nitro-3-trichloromethylaziridines are stereohomogeneous
and have the geometry, such that the nitro and aryl substituents are in the trans positions with respect to the trichloromethyl group. The chemical bonding in the crystal and the gas phase was investigated
based on high-resolution X-ray diffraction analysis of the electron density distribution and quantum chemical calculations. 相似文献
97.
Gazieva G._A. Nelyubina Yu. V. Kravchenko A. N. Sigachev A. S. Glukhov I. V. Struchkova M. I. Lyssenko K. A. Makhova N. N. 《Russian Chemical Bulletin》2009,58(9):1945-1954
α-Thioureidoalkylation of urea heteroanalogs such as thiosemicarbazide, amino-guanidine, sulfamide, and sulfonamides with
4,5-dihydroxyimidazolidine-2-thiones has been studied. Previously unknown 4,5-bis[thiosemicarbazido(guanidinoamino)]imidazolidine-2-thiones,
5,7-dialkylperhydroimidazo[4,5- e][1,2,4]triazine-3,6-dithiones, 4,6-diethyl-5(3H)-thioxotetrahydro-1 H-imidazo[4,5- c][1,2,5]thiadiazole 2,2-dioxide, and 1,3-dialkyl-4-[guanidinoimino(arylsulfonylimino)]imidazolidine-2-thiones have been synthesized. 相似文献
98.
Ya. Z. Voloshin E. G. Lebed S. Yu. Erdyakov I. G. Makarenko K. A. Lyssenko Z. A. Starikova M. E. Gurskii Yu. N. Bubnova 《Russian Chemical Bulletin》2006,55(11):1971-1981
Template condensation on the iron(II) ion matrix of three cyclohexanedione-1,2-dioxime molecules with esters of 1,4-pentadienylboronic acids afforded apically functionalized bis(diolefin)-containing clathrochelates, which are new potential monomers for the preparation of functionalized carbochain polymers. The complexes were characterized by the data of elemental analysis, UV-Vis spectroscopy, 1H, 11B, and 13C NMR spectroscopy, 57Fe Mössbauer spectroscopy, IR spectroscopy, and MALDI-TOF mass spectrometry. The molecular and crystal structures of the clathrochelates synthesized and the electron density distribution on a molecule of one of them were determined by X-ray diffraction analysis. 相似文献
99.
Lyssenko KA Korlyukov AA Golovanov DG Ketkov SY Antipin MY 《The journal of physical chemistry. A》2006,110(20):6545-6551
The high-resolution X-ray diffraction analysis of the electron density distribution and plane-wave density functional theory has been applied to estimate the lattice energy and barrier to rotation of a benzene ring in the crystal of (eta(6)-C(6)H(6))(2)Cr. Experimental data made it possible to perform analysis of the metal-(pi-ligand) bond and estimate the nature and energy of weak H...H and H...C intermolecular interactions in the crystal. Summation of the intermolecular H...H and H...C interaction energies makes it possible to reproduce the experimental sublimation enthalpy value with high accuracy. 相似文献
100.
S. Z. Vatsadze A. V. Dolganov A. V. Yakimanskii M. Ya. Goikhman I. V. Podeshvo K. A. Lyssenko A. L. Maksimov T. V. Magdesieva 《Russian Chemical Bulletin》2010,59(4):724-732
The newly synthesized complex (2) of copper(I) chloride with di-n-hexyl 2,2′-biquinoline-4,4′-dicarboxylate (L) was spectroscopically and electrochemically characterized. The X-ray diffraction
study showed that the crystals of complex 2 consist of the dinuclear moieties [L2Cu1
2(μ-Cl)2] containing Cu2(μ-Cl)2 clusters. Spectrophotometric studies and ESI-mass spec-trometric measurements showed that after the dissolution of complex
2 in acetonitrile (AN) and N-methyl-2-pyrrolidone (NMP), the solution contained not only the dinuclear complexes [L2Cu1
2(μ-Cl)2] but also [L2Cu1]Cl, [LCu1Cl(Sol)], and [Cu1Cl(Sol)] (Sol is the solvent). The electrochemical data also confirm the conclusion that bridged dinuclear chloride complex
2 dissociates both in NMP and AN to form the tetrahedral bis-biquinoline complex [L2Cu1]Cl. In solutions of complex 2 in alcohols and N,N-dimethylformamide (DMF), only [L2Cu1]Cl and [Cu1Cl(Sol)] are present. In EtOH, AN, and DMF, [Cu1Cl(Sol)] undergoes disproportionation to [Cu11Cl(Sol)] and Cu0. 相似文献