全文获取类型
收费全文 | 329篇 |
免费 | 3篇 |
国内免费 | 1篇 |
专业分类
化学 | 248篇 |
力学 | 2篇 |
数学 | 34篇 |
物理学 | 49篇 |
出版年
2020年 | 5篇 |
2019年 | 10篇 |
2018年 | 8篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 5篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 14篇 |
2010年 | 11篇 |
2009年 | 14篇 |
2008年 | 6篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 5篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 15篇 |
2000年 | 9篇 |
1999年 | 7篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 14篇 |
1989年 | 7篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1981年 | 4篇 |
1980年 | 3篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 6篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 2篇 |
排序方式: 共有333条查询结果,搜索用时 31 毫秒
61.
A. R. Tuktarov V. V. Korolev L. M. Khalilov A. G. Ibragimov Yu. M. Dzhemilev 《Russian Journal of Organic Chemistry》2009,45(11):1594-1597
The selective cyclopropanation of C60-fullerene with diazomethane was performed under the catalysis with Pd(acac)2, and individual 5,6-open and 6,6-closed cycloadducts were obtained. 相似文献
62.
A model of a degenerate ideal gas of nucleons and electrons in a superstrong magnetic field is used to describe the state of matter in the central region of a strongly magnetized neutron star. The influence of a constant uniform superstrong magnetic field on the equilibrium conditions and the equation of state for the degenerate gas of neutrons, protons, and electrons is investigated in the framework of this model. The contribution determined by the interaction of the anomalous magnetic moments of the fermions with the magnetic field is taken into account. The influence of the superstrong magnetic field on the process of gravitational collapse of a magnetized neutron star is discussed under the assumption that the central region of the star consists mostly of degenerate neutrons. We show that if the densities of electrons, protons, and neutrons are relatively low depending on the field strength, the fermion gases in a superstrong uniform magnetic field become totally polarized with respect to the spin. We discuss the possibility of spontaneous magnetization occurring in a system of degenerate neutrons where the exchange interaction effects are taken into account. 相似文献
63.
V. R. Khalilov 《Theoretical and Mathematical Physics》2000,122(3):312-322
The creation of electron-positron pairs from a vacuum by an external Coulomb field is examined within (2+1)-dimensional quantum
electrodynamics. If the electromagnetic coupling constant exceeds 0.62 (Z= 85), then in a simple model with a finite-size
nucleus, the lower electron level crosses the boundary of the negative-energy continuum (i.e., Dirac sea), and a hole (i.e.,
positively charged fermion) appears in the negative-energy continuum. An equation is obtained that describes the levels of
the ground and excited electron states in a strong Coulomb field of the nucleus. The critical nucleus charge is found for
a few lowest electron states. The critical charge in 2+1 dimensions is significantly smaller than in 3+1 dimensions. The problem
is reduced to the case of a bounded Coulomb field in 1+1 dimensions without a magnetic field. The interaction of a fermion
and an external scalar field in 2+1 and 1+1 dimensions is investigated.
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol 122, No. 3, pp. 372–384, March, 2000 相似文献
64.
V. R. Khalilov 《Theoretical and Mathematical Physics》2000,125(1):1413-1430
The Green's function of the Dirac equation with an external stationary homogeneous magnetic field in the (2+1)-dimensional
quantum electrodynamics (QED
2+1) with a nonzero fermion density is constructed. An expression for the polarization operator in an external stationary homogenous
magnetic field with a nonzero chemical potential is derived in the one-loopQED
2+1 approximation. The contribution of the induced Chern—Simons term to the polarization operator and the effective Lagrangian
for the fermion density corresponding to the occupation of n relativistic Landau levels in an external magnetic field are
calculated. An expression of the induced Chern—Simons term in a magnetic field for the case of a finite temperature and a
nonzero chemical potential is obtained.
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 125, No. 1, pp. 132–151, October, 2000. 相似文献
65.
The np 3 P 0, 1, 2 states of Cd I in the range n=15–60 were studied by three-stage laser excitation and electric-field ionization for the measurement of kinetics of cadmium evaporation. The saturated vapor pressure and the evaporation heat of cadmium in a temperature range of 300–535 K were determined. 相似文献
66.
Kuramshina A. E. Khalikov R. A. Kataev V. A. Tyumkina T. V. Meshcheryakova E. S. Khalilov L. M. Kuznetsov V. V. 《Russian Journal of Organic Chemistry》2020,56(10):1764-1769
Russian Journal of Organic Chemistry - The structure of 5-methyl-2,2-diphenyl-1,3-dioxane has been studied by1H and 13C NMR spectroscopy and X-ray analysis. Its molecules in crystal, as well as in... 相似文献
67.
68.
A. G. Mustafin I. N. Khalilov E. V. Tal'vinskii I. B. Abdrakhmanov L. V. Spirikhin G. A. Tolstikov 《Chemistry of Natural Compounds》1992,28(5):479-483
A convenient method is proposed for the synthesis of the alkaloid ellipticine, which possesses a pronounced antitumoral activity.
The interaction of 3-bromocyclohexene (1 equiv.) and 2,5-xylylidine (4 equiv., 150°C, 5 h) gave a mixture of hexa- and tetrahydrocarbazoles
which was dehydrogenated in the presence of Pd/C to the key synthon 1,4-dimethylcarbazole. The formylation of the carbazole
by the Vilsmeier-Haack reaction, interaction with 2,2-diethoxyethylamine, and reduction of the imine formed over Raney nickel
led to 3-(2,2-diethoxyethylaminomethyl)-1,4-dimethylcarbazole, the boiling of the N-tosylate of which gave ellipticine in
high yield.
Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, Ufa. Translated from Khimiya Prirodnykh Soedinenii,
No. 5, pp. 549–554, September–October, 1992. 相似文献
69.
Viktor N. Odinokov Olga S. Kukovinets Leonard M. Khalilov Genrikh A. Tolstikov Alexander Yu. Kosnikov Sergei V. Lindeman Yury T. Struchkov 《Tetrahedron letters》1985,26(47):5843-5844
The formation of the product of intramolecular interaction of a zwitterion and a methoxycarbonyl group was observed in the process of ozonating dimethyl ester of endo,cis-bicyclo [2,2,1]hept-5-en-2,3-dicarbonic acid in diethyl ether. The structure of racemic endo,cis-4-methoxy-5-methoxycarbonyl-6-formyl-1,4-epoxy-2,3-dioxacyclopenta[2,3-δ] cyclohexane was established by an X-ray structure analysis. 相似文献
70.
R. R. Muslukhov L. M. Khalilov A. G. Ibragimov A. P. Zolotarev U. M. Dzhemilev 《Russian Chemical Bulletin》1992,41(12):2172-2179
The13C NMR spectra of a new class of tri- and tetracyclic organoaluminum and organosulfur bridge-type compounds, containing five-membered heterocycles with anexo-orientation, are discussed. The assignment of the signals and determination of the isomerism of the compounds studied were performed using the spectra of their hydrocarbon analogs, additive calculations, and an analysis of the spectra of products of deuteration and hydrolysis of organoaluminum compounds.For previous communication, see [1].Institute of Organic Chemistry, Urals Branch, Russian Academy of Sciences, 450054 Ufa, Bashkortostan, Russia. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 12, pp. 2742–2750, December, 1992. 相似文献