全文获取类型
收费全文 | 494篇 |
免费 | 4篇 |
专业分类
化学 | 386篇 |
力学 | 10篇 |
数学 | 35篇 |
物理学 | 67篇 |
出版年
2022年 | 10篇 |
2021年 | 6篇 |
2020年 | 8篇 |
2019年 | 6篇 |
2018年 | 3篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 4篇 |
2014年 | 14篇 |
2013年 | 26篇 |
2012年 | 10篇 |
2011年 | 18篇 |
2010年 | 8篇 |
2009年 | 11篇 |
2008年 | 23篇 |
2007年 | 24篇 |
2006年 | 21篇 |
2005年 | 16篇 |
2004年 | 15篇 |
2003年 | 12篇 |
2002年 | 19篇 |
2001年 | 26篇 |
2000年 | 13篇 |
1999年 | 14篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 12篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 8篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1973年 | 7篇 |
1967年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有498条查询结果,搜索用时 15 毫秒
1.
Romanenko G. V. Fokin S. V. Bogomyakov A. S. Zueva E. M. Ovcharenko V. I. 《Journal of Structural Chemistry》2022,63(3):441-450
Journal of Structural Chemistry - The structures of Ni(II), Cu(II), and Zn(II) complexes with anions of 2,5-pyrrolyl-disubstituted nitronyl nitroxide (L1) and iminonitroxide (L2) diradicals (HL1 is... 相似文献
2.
Romanenko G. V. Letyagin G. A. Maryunina K. Yu. Bogomyakov A. S. Nishihara S. Inoue K. Ovcharenko V. I. 《Russian Chemical Bulletin》2020,69(8):1530-1536
Russian Chemical Bulletin - The study is concerned with structural rearrangements in the crystals of heterospin complexes Cu(hfac)2 with nitroxide radicals LR (hfac is hexafluoroacetylacetonate, LR... 相似文献
3.
4.
Sokolova N. P. Varand V. L. Romanenko G. V. Lisoivan V. I. Fadeeva V. P. Sheludyakova L. A. 《Russian Journal of Coordination Chemistry》2003,29(5):362-368
Two isomers with empirical formula C6H6F9O9Tb are synthesized and their structures are studied. Isomerism was found to arise due to different positions of a proton. Crystals of two isomers are isostructural and form continuous series of solid solutions with C6H6F9O9Eu. 相似文献
5.
6.
An anomaly is found in the vicinity of Tmax 560$ K on electric resistance versus temperature curves for yttrium hightemperature superconductors of the 123 phase. Xray phase analysis suggests a structural phase transition in the vicinity of Tmax due to oxygen redistribution in the mobile sublattice of this compound. Investigation of samples with Y partially replaced by Ca has shown that the structural phase transition does not depend on carrier concentration in the conduction band. 相似文献
7.
V. M. Cherkasov G. Ya. Remennikov A. A. Kisilenko E. A. Romanenko 《Chemistry of Heterocyclic Compounds》1980,16(2):179-182
The corresponding σ complexes of the Meisenheimer type, viz., anions of the potassium salts of 6H-5-nitro-6-acetonylpyrimidines,
were obtained and isolated in the reaction of 5-nitro-, 5-nitro-4-methoxy-, 5-nitro-2-methoxy-, and 5-nitro-2,4-dimethoxypyrimidines
with acetone in the presence of potassium hydroxide. The structures of the complexes were proved by means of the PMR, IR,
and UV spectra. It is shown that the acetone anion in all cases adds to the methoxy-unsubstituted position of the pyrimidine
ring, whereas nucleophilic attack takes place at the C4 atom when the 2 and 4 positions are free.
See [1] for communication 1.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 239–242, February, 1980. 相似文献
8.
The crystal structure was found for the Ni(II) complex with the nitroxyl radical derivative of 3-imidazoline L=C10H13N2O2F3 and 1-butanol C4H9OH with the formula NiL2(n-C4H9OH)2 (a=10.907(2), b=16.769(5), c=12.321(3) Å, =96.33(2), =120.36(1), =106.3(2)o, V = 1780.7(7) Å3, dcalc=1.32 g/cm3, space group P1, Z=2, R=0.072). The structure was molecular in nature. Octahedral coordination of the nickel ion was found with the oxygen and nitrogen atoms of two bidentate L in the equatorial plane [Ni–O, 2.13 Å (av.); Ni–N, 1.99 Å (av.)] and the oxygen atoms [Ni–OOH, 2.13 Å (av.)] of the OH groups of the alcohol molecules in the axial positions. The rather strong hydrogen bonds between the coordinated OH groups of the alcohol and oxygen atoms of the
groups of the adjacent complex molecules (O...O, 2.78–2.84 Å) delineate layers, in which the distances between the paramagnetic sites of adjacent molecules Ni... are shorter than the intramolecular distances and much shorter than the analogous distances between adjacent layers. On the whole, this structure is similar to those of analogous compexes with other alcohols previously studied.Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 119–125, March–April, 1993. 相似文献
9.
E. V. Tretyakov A. S. Bogomyakov E. Yu. Fursova G. V. Romanenko V. N. Ikorskii V. I. Ovcharenkoa 《Russian Chemical Bulletin》2006,55(3):457-463
The molecular and crystal structures of porphyrexides, viz., 4-amino-2-imino-(1) and (Z)-2-amino-4-bromoimino-5,5-dimethyl-4,5-dihydro-1H-imidazole 1-oxyls (7), and their diamagnetic precursors were determined. Compound 1 is kinetically unstable because it is oxidized with atmospheric oxygen to form (E)-1,2-bis[1-amino-1-(cyanoimino)-2-methyl-propan-2-yl]diazene 1,2-dioxide.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 441–447, March, 2006. 相似文献
10.
Kiskin M. A. Shvedenkov Y. G. Ikorskii V. N. Romanenko G. V. Ovcharenko V. I. 《Russian Chemical Bulletin》2003,52(1):265-266
The reaction of FeII and FeIII salts with tetrabutylammonium squarate in an aqueous solution gives rise to a new molecular magnet (T
c = 8.6 K). 相似文献