全文获取类型
收费全文 | 306篇 |
免费 | 2篇 |
专业分类
化学 | 268篇 |
数学 | 2篇 |
物理学 | 38篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2015年 | 4篇 |
2014年 | 4篇 |
2013年 | 9篇 |
2012年 | 9篇 |
2011年 | 18篇 |
2010年 | 17篇 |
2009年 | 24篇 |
2008年 | 23篇 |
2007年 | 26篇 |
2006年 | 19篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 6篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 3篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 12篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1976年 | 3篇 |
1973年 | 1篇 |
排序方式: 共有308条查询结果,搜索用时 15 毫秒
1.
I. V. Ukrainets S. G. Taran O. V. Gorokhova P. A. Bezuglyi A. V. Turov 《Chemistry of Heterocyclic Compounds》1994,30(2):204-207
In a solution of DMF, 2-carbethoxymethyl-4H-3,1-benzoxazin-4-one reacts with primarily aromatic amines basically with the formation of the corresponding 2-carbethoxymetlzyl-3-arylquinazolin-4(3H)-ones. Possible mechanisms of these chemical transformations are reported and discussed.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 225–228, February, 1994. Original article submitted June 28, 1993. 相似文献
2.
Structural characterisation of such bio-objects as fibrinogen solution, yeast cells, wheat seeds and bone tissues has been done using two versions of cryoporometry based on the integral Gibbs-Thomson (IGT) equation for freezing point depression of pore liquids and the measurements by 1H NMR spectroscopy (180-200 < T < 273 K) and the thermally stimulated depolarisation current (TSDC) method (90 < T < 273 K) of structured water. The IGT equation was solved using a self-consisting regularization procedure including the maximum entropy principle applied to the distribution function of pore size (PSD). Both methods give clear pictures of changes in the structural characteristics caused, e.g., by hydration and swelling of wheat seeds and yeast cells, coagulation and interaction of fibrinogen with solid nanoparticles in the aqueous media, and the human bone tissue disease. 相似文献
3.
Purely antiferromagnetic intrinsic oscillations of magnetic ions in a tetragonal ferrimagnet are considered. The magnetic ions occupy two double positions (forming four magnetic sublattices) so that the center of symmetry for each position is not a closed element. Not involving the total magnetization vector, the oscillations are not excited by the magnetic field; however, the oscillations can be excited by an alternating electric field or by a combination of a constant electric field and the alternating magnetic field of a certain frequency. This phenomenon is a dynamic manifestation of the magnetoelectric interaction. These oscillations, representing a new special type of spin waves (magnons), were called antimagnons. The intrinsic frequencies of antimagnons, as well as the corresponding susceptibilities, were determined. Quantitative estimates were obtained for a Mn2Sb-based ferrimagnetic phase in both easy-axis and easy-plane orientation states. 相似文献
4.
V. P. Nekhoroshev Yu. P. Turov A. V. Nekhorosheva V. D. Ogorodnikov K. N. Gaevoi 《Russian Journal of Applied Chemistry》2006,79(5):833-840
The composition and structure of low-molecular-weight products of thermal oxidative degradation of atactic polypropylene were studied. 相似文献
5.
M. I. Kurkin V. V. Leskovets V. V. Nikolaev E. A. Turov L. V. Turov 《Physics of the Solid State》2003,45(4):685-690
The possibility of excitation of NMR signals by an ac electric field in magnetically ordered crystals is discussed. Such signals can be recorded using the time-dependent component of the electric polarization vector. It is assumed that the electric and magnetic characteristics are coupled to each other through magnetoelectric and antiferroelectric interactions. Several types of magnetic structures are analyzed in which these interactions are not forbidden by symmetry. Such structures include two-sublattice single-position ferro-and antiferromagnetic phases in centrosymmetrical crystals, two-sublattice magnetic crystals without a center of symmetry (such as KNiPO4), and four-sublattice antiferromagnetic crystals with three types of antiferromagnetism vectors (such as Cr2O3 and α-Fe2O3). 相似文献
6.
S. V. Nekhoroshev Yu. P. Turov V. P. Nekhoroshev A. K. Golovko 《Russian Journal of Applied Chemistry》2006,79(7):1191-1195
A method for identification of explosive-containing commercial articles is suggested. The method is based on chromatographic analysis of petroleum products present in the articles as process admixtures and structural components. 相似文献
7.
The 2-meter liquid-hydrogen bubble chamber is exposed to a separated beam of α particles from the ITEP synchrotron. The momentum of the incident 4He nuclei, averaged over the fiducial volume of the chamber, is 5 GeV/c (the kinetic energy of initial protons in the nucleus rest frame is T
p
=620 MeV). The spectral functions of decays α→tp and α→τn) are extracted in the 4π geometry (the latter is extracted for the first time) from the exclusive reactions αp→tpp and αp→τpn in the spectator momentum region 0<q<0.3 GeV/c. The pole dominance criteria are carefully checked. Extrapolation of the nuclear vertex function to the pole gives a lower
bound on the nuclear vertex constant. Our experimental data are compared with the results of other studies and with theoretical
calculations.
Pis’ma Zh. éksp. Teor. Fiz. 66, No. 2, 69–74 (25 July 1997)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
8.
The reaction of N-R-substituted amides of 2-carboxymalonanilic acid with the equimolar amount of o-phenylenediamine was studied under conditions of thermolysis. It was established that the main products of this reaction are the corresponding amides of benzimidazolyl-2-acetic acid and 1H-2-oxo-3-(benzimidazolyl-2)-4-hydroxyquinoline. Mechanisms of the indicated chemical conversions are discussed. The data on the study of the anticonvulsive activity of the compounds synthesized are presented.For Communication 15, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1105–1108, August, 1993. 相似文献
9.
R. I. Vas’kevich P. V. Savitskii Yu. L. Zborovskii V. I. Staninets A. V. Turov A. N. Chernega 《Russian Journal of Organic Chemistry》2006,42(9):1396-1402
Reactions of substituted 1-(thieno[2,3-d]pyrimidin-2-yl)-4-arylthiosemicarbazides with methyl iodide led to the formation of fused triazolothienopyrimidine derivatives. 相似文献
10.
I. V. Ukrainets P. A. Bezuglyi V. I. Treskach A. V. Turov 《Chemistry of Heterocyclic Compounds》1992,28(2):198-200
3-(2-Benzimidazolyl)-4-hydroxy-2-quinolone was unexpectedly obtained as the principal reaction product on fusion of 2-carbethoxymethyl-4H-3,1-benzoxazin-4-one with o-phenylenediamine. A possible mechanism of its formation is presented.For Communication 2 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 239–241, February, 1992. 相似文献