全文获取类型
收费全文 | 146篇 |
免费 | 0篇 |
专业分类
化学 | 126篇 |
晶体学 | 3篇 |
力学 | 1篇 |
数学 | 9篇 |
物理学 | 7篇 |
出版年
2022年 | 2篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 2篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2011年 | 7篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2007年 | 3篇 |
2006年 | 2篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1998年 | 6篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1983年 | 3篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1970年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有146条查询结果,搜索用时 484 毫秒
1.
A. I. Kolesnikov I. A. Kaplunov I. V. Talyzin S. A. Tret’yakov O. V. Gritsunova E. Yu. Vorontsova 《Crystallography Reports》2008,53(7):1144-1149
A computer simulation and measurements of the light transmittance of germanium and paratellurite crystals of different thickness
were used to show that, at scattering probabilities of photons comparable to their absorption probabilities, the standard
methods for calculating light extinction coefficients on the basis of the Bouguer law lead to rough errors in estimation of
the optical quality of a material. 相似文献
2.
M. M. Krayushkin M. A. Kalik L. G. Vorontsova E. Yu. Zvezdina M. G. Kurella 《Russian Chemical Bulletin》1993,42(7):1204-1208
9-Methyl-3,3a,4,5-tetrahydro-6H-thieno[2,3-b]thiocino[4,5-c]isoxazole and 9-hydroxyimino-2-methyl-7-methylene-6, 7,8,9-tetrahydro-5H-thieno[2,3-b]thiocine have been prepared for the first time by the oxidation of 2--alkenylthio-3-thiophenecarbaldoximes with NaOCl. X-ray structural investigations of thieno[2,3-b]thiocine and 2-homomethallylthio-5-methyl-3-thiophenecarbaldoxime have been carried out.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1262–1266, July, 1993. 相似文献
3.
Krayushkin M. M. Shirinian V. Z. Belen"kii L. I. Shadronov A. Yu. Vorontsova L. G. Starikova Z. A. 《Russian Chemical Bulletin》2002,51(8):1510-1514
The conditions for acylation of 2,5-dimethylthiophene with squaric acid dichloride were optimized, and 3,4-bis(2,5-dimethylthiophen-3-yl)cyclobut-3-ene-1,2-dione was obtained in good yield. X-ray diffraction analysis demonstrated that the by-product has the structure of 1a,1b-dichloro-5-(2,5-dimethylthiophen-3-yl)-3-hydroxy-4,5a-dimethyl-1b,4a,5,5a-tetrahydro-1aH-1-thiacyclopropa[a]pentalen-2-one. 相似文献
4.
M. G. Kurella L. G. Vorontsova S. V. Baranin A. Dib V. A. Dorokhov 《Russian Chemical Bulletin》1991,40(1):156-160
X-ray diffraction has been used to establish the crystalline and molecular structure of the intracomplex 2-[(dibutylboryloxy)(butyl)borylamino]4-methylpyridine. In the crystal, the molecule forms weak intermolecular N(H)...O hydrogen bonds. The bicyclic portion of the molecule is nearly planar. From the bond lengths in the ring, which incorporates boron atoms of differing hybridization (sp3 and sp2), it follows that delocalization of electron density extends only over the amidine fragment. Quantum chemical calculations (MO LCAO, version CNINDO/2) show that the electron density at the endocyclic nitrogen of the aminopyridine system coordinated with boron is lower than that at the endocyclic nitrogen of the aminopyridine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 173–177, January, 1991. 相似文献
5.
The molecular and crystal structures of diphenylboron chelates of acetylketeneN-benzoylaminal and 2-(N-benzoyl)diaminomethylene-4-dimethylaminomethylenecyclohexane-1,3-dione and the structure of the difluoroboron complex of diacetylketeneN-benzoylaminal were established. It was found that the aminovinylcarbonyl fragment of the ligand is involved in the formation of a boron-containing ring. A delocalized -electron system over the NCCCO fragment of the chelate ring is characteristic of the molecules studied both in crystals and solutions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2541–2546, October, 1996. 相似文献
6.
Tashkhodzhaev B. Vorontsova L. G . Alashev F . D. 《Journal of Structural Chemistry》1977,18(2):316-318
Journal of Structural Chemistry - 相似文献
7.
M. M. Krayushkin L. G. Vorontsova M. G. Kurella M. A. Kalik E. Yu. Zvezdina 《Russian Chemical Bulletin》1994,43(10):1700-1702
The crystal and molecular structure of a novel heterocyclic system, 8-methyl-3,3a,4,5-tetrahydrothieno[3,2:6,7]thiepino[4,5-c]isoxazole, has been determined by X-ray analysis. The seven-membered ring has the boat conformation (B), while the isoxazoline cycle has the flat chair conformation (3E). There are strong steric strains between the vicinal protons at the C(3a), C(3), and C(4) atoms.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1795–1797, October, 1994. 相似文献
8.
V. A. Dorokhoy L. G. Vorontsova M. G. Kurella L. I. Parfenova 《Russian Chemical Bulletin》1996,45(11):2592-2594
A bis-diphenylboron chelate has been synthesized from 3-(diaminomethylene)pentane-2,4-dione through the action of (butylthio)diphenylborane and its molecular and crystal structures have been determined. The two boron -containing rings have the same six-membered skeleton but differ substantially in conformation and geometric parameters.Translated fromlzvestiva Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2733–2735, November, 1996, 相似文献
9.
Rozenberg V. I. Sergeeva E. V. Kharitonov V. G. Vorontsova N. V. Vorontsov E. V. Mikul'shina V. V. 《Russian Chemical Bulletin》1994,43(6):1018-1023
The cross-coupling reactions of 4-bromo[2.2]paracyclophane withp-tolylmagnesium bromide in the presence of various palladium and nickel complexes have been studied. It was found that [1,1 -bis(diphenylphosphinoferrocene)]palladium dichloride (PdCl2 · dppf) shows the highest catalitic activity in this reaction. A series of new mono- and diaryl [2.2]paracyclophane derivatives with various substituents in the arene ring have been synthesized using this catalyst. It was shown that it is possible to cross-couple organozinc [2.2]paracyclophane derivatives with aromatic bromides. The composition and structure of the compounds obtained have been established on the basis of elemental analysis and spectral data. Some correlations between the structure and spectral parameters of mono- and diarylsubstituted [2.2]paracyclophanes have been found.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1081–1085, June, 1994.The present work was financially supported by the Russian Foundation for Basic Research (Project No. 93-03-5246).The authors wish to express their gratitude to Prof. N. A. Bumagin for his scientific interest and helpful discussions. 相似文献
10.
Natalia V. Vorontsova Galina S. Bystrova Dmitrii Yu. Antonov Anna V. Vologzhanina Ivan A. Godovikov Michail M. Il’in 《Tetrahedron: Asymmetry》2010,21(6):731-738
New planar-chiral hydroxycarbonyl [2.2]paracyclophane derivatives, 4-acetyl-13-bromo-5-hydroxy[2.2]paracyclophane (Br-АНРС, 63%) and 4-benzoyl-13-bromo-5-hydroxy[2.2]paracyclophane (Br-BHPC, 53%), were synthesized and reacted with the enantiomers of α-phenylethylamine to form corresponding Schiff bases, 12-bromo-4-hydroxy-5[1-(1-phenyl-ethylimino)-ethyl]-[2.2]paracyclophane and 12-bromo-4-hydroxy-5[1-(1-phenyl-ethylimino)-(phenyl)methylen-[2.2]paracyclophane. The diastereomers of the imines were resolved and their absolute configurations and consequently the corresponding configurations of the enantiomers of Br-АНРС were determined by X-ray diffraction. Enantiomerically pure Schiff bases were applied as ligands to form catalysts for the enantioselective addition reaction of diethylzinc with benzaldehyde where 1-phenylpropanol was obtained with 77–91% ee. 相似文献