全文获取类型
收费全文 | 496篇 |
免费 | 4篇 |
专业分类
化学 | 387篇 |
力学 | 10篇 |
数学 | 35篇 |
物理学 | 68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 | 9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 | 6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500条查询结果,搜索用时 46 毫秒
11.
E. V. Tretyakov S. E. Tolstikov G. V. Romanenko Yu. G. Shvedenkov R. Z. Sagdeev V. I. Ovcharenko 《Russian Chemical Bulletin》2005,54(9):2169-2181
A new approach to the synthesis of polyfunctional pyrazolyl-substituted nitronyl nitroxides was developed based on the presynthesized
pyrazole derivatives prepared by 1,3-dipolar cycloaddition. The structures of the resulting mono-and biradicals were confirmed
by X-ray diffraction.
Dedicated to Academician A. L. Buchachenko on the occasion of his 70th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 2105–2116, September, 2005. 相似文献
12.
Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 1, pp. 93–99, January–February, 1992. 相似文献
13.
2-Chloro-3-formylquinoxaline was synthesized from 2-chloro-3-methylquinoxaline by the Kröhnke method, and the properties of its phenylhydrazone were studied. It was found that 2-Y-3-formylquinoxalines display an anomalously low reactivity as compared with 2-Y-benzoylquinoxalines (Y=H, OH, Cl) in the synthesis of pyrazolo[3,4-b]quinoxalines.See [1] for communication IV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 852–856, June, 1973. 相似文献
14.
A way to determine the form of an analytical signal without accounting of the base line is described. It is based on subtraction of two peaks. The validity of correction of the base line inclination with the help of a linear function is indicated. The ability to determine the true form of the analytical signal in case of overlapping signals is proved. The approach was applied to define the degree of non-additivity of the analytical signal and the character of change of the peak shape as a function of concentration. 相似文献
15.
Quantum chemical study of the appearance of the “α-effect” in35Cl NQR spectra of chloromethylsilanes
We consider the connection between the electron distribution in ClCH2MX1X2X3 molecules (M = C, Si) calculated by the CNDO/2 method and the experimental35Cl NQR frequencies. We show that the ratio of the NQR frequencies for chloromethylsilanes and their organic analogs can be explained on the basis of ideas concerning the totality of induction and conjugation effects influencing the population of the orbital of the chlorine atom which participates in formation of the C-Cl bond.Translated from Teoreticheskaya i Eksperimental'naya Khimiya, Vol. 26, No. 2, pp. 241–244, March–April, 1990. 相似文献
16.
Tretyakov E. V. Romanenko G. V. Shvedenkov Yu. G. Ovcharenko V. I. Sagdeev R. Z. 《Russian Chemical Bulletin》2004,53(6):1301-1304
Esters of 4,5-dihydro-1H-imidazole-1-oxyl-3-oxide-carboximidic acid were synthesized. Their structures and magnetic properties were investigated. 相似文献
17.
S. V. Fokin G. V. Romanenko M. Baumgarten V. I. Ovcharenko 《Journal of Structural Chemistry》2003,44(5):864-869
The organomercury biradical HgL2 (L is deprotonated 4,4,5,5-tetramethyl-2-imidazoline-3-oxide-1-oxyl) is capable of performing the bridging function for design of multinuclear heterospin systems. This paper describes synthesis and crystal structure of HgL2 and the first multinuclear complexes of Cu(hfac)2 with HgL2. 相似文献
18.
Rudzevich VL Gornitzka H Romanenko VD Bertrand G 《Chemical communications (Cambridge, England)》2001,(17):1634-1635
Addition of an excess of BunLi to the bis(borano)phosphide complex [Ar*PH(BH3)2]-Li+ 1 (Ar* = 2,4,6-tri-tert-butylphenyl) and subsequent treatment with BH3, gives the anionic complex [Ar*P(BH3)(mu-BH2)2H]-Li+ 2 instead of the expected tris(borano)phosphide dilithium, [Ar*P(BH3)3]2-2Li+ 3. 相似文献
19.
G. N. Il’inich A. V. Romanenko R. I. Kvon V. B. Fenelonov V. I. Zaikovskii A. V. Ishchenko 《Kinetics and Catalysis》2007,48(1):103-115
Nitrogen-containing catalytic filamentous carbon (N-CFC) of chemical composition NC18-NC104 has been synthesized by the decomposition of pyridine (Py) from gaseous mixtures with argon or H2 at 550–800°C on Ni/Al2O3 (Ni) and Ni-Cu/Al2O3 (Ni-Cu) high-percentage catalysts. The activity of the Ni-Cu catalyst in Py decomposition in mixtures with H2 is about one order of magnitude higher than its activity in Py/Ar mixtures (more than 70 g N-CFC per metal gram in 4.5 h at 750°C), which is interpreted as arising from the nickel-catalyzed hydrogenation of Py. The formation and growth of carbon fibers occurs through the decomposition of Py (from Ar/Py mixtures) and/or Py hydrodenitrification products (from H2/Py mixtures). The carbon material has been characterized by elemental analysis, low-temperature nitrogen adsorption, high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS). The effect of the noncatalytic reactions of Py and its transformation products on the composition and texture of N-CFC is discussed. 相似文献
20.
S. A. Gromilov I. A. Baidina P. A. Stabnikov G. V. Romanenko 《Journal of Structural Chemistry》2004,45(3):476-481
An X-ray diffraction investigation has performed for copper(II) bis-hexafluoroacetylacetonate (Bruker AXS P4 automatic diffractometer, MoK
radiation, t = –25°C). Crystal data for C10H2CuF12O4: a = 5.530(1) Å, b = 6.038(1) Å, c = 11.266(2) Å, = 95.948(3)°, = 101.743(3)°, = 92.298(3)°, space group; P1, V = 365.6(1) Å3, Z = 1, d
calc = 2.169 g/cm3. The square-planar environment of the copper atom (Cu-Oav 1.912 Å, O-Cu-Oav 93°) is completed to bipyramidal by two fluorine atoms of the neighboring molecules, Cu...F 2.71 Å and 2.75 Å.Original Russian Text Copyright © 2004 by S. A. Gromilov, I. A. Baidina, P. A. Stabnikov, and G. V. RomanenkoTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 502–507, May–June 2004. 相似文献