全文获取类型
收费全文 | 383篇 |
免费 | 0篇 |
专业分类
化学 | 177篇 |
晶体学 | 14篇 |
力学 | 21篇 |
数学 | 25篇 |
物理学 | 146篇 |
出版年
2022年 | 5篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 5篇 |
2014年 | 4篇 |
2013年 | 15篇 |
2012年 | 12篇 |
2011年 | 19篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 25篇 |
2007年 | 9篇 |
2006年 | 18篇 |
2005年 | 18篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 17篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1995年 | 9篇 |
1994年 | 3篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1983年 | 10篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 6篇 |
1969年 | 2篇 |
1966年 | 1篇 |
排序方式: 共有383条查询结果,搜索用时 11 毫秒
131.
132.
V. P. Kozhevnikov V. E. Troitskii S. V. Trubnikov Yu. M. Shirokov 《Theoretical and Mathematical Physics》1972,10(1):30-37
Conclusions The present paper has been devoted primarily to kinematics. In the next paper the results we have obtained will be used for a realistic calculation of the form factors of the bound state of the n-p system-the deuteron.Two results are of independent interest. First, the inequality of the initial, , and final, , masses of the n-p system and the parametrization (28) result in the appearance of the transition form factor f21 (–), which, generally speaking, makes a contribution to the matrix element pn|j|pn and also to the electrosplitting of the deuteron [15]. Secondly, we have found an admixture of the magnetic form factors of the proton and neutron in the charge form factor of the n-p system. This admixture will also be retained in the charge form factor of the deuteron. This mixing is due to the relativistic spin rotation and may be important in the solution of the problem that is the inverse of that we have been considering-the determination of information about the electromagnetic form factors of the neutron from the known form factors of the deuteron and proton. Since the experimental charge form factor of the neutron is small in magnitude, the calculated value of GEp is very sensitive to theoretical and experimental corrections (see, for example, [16]).M. V. Lomonosov Moscow State University. V. A. Steklov Mathematics Institute, Academy of Sciences of the USSR. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 10, No. 1, pp. 45–57, January, 1972. 相似文献
133.
E. S. Fradkin A. A. Kozhevnikov M. Ya. Palchik A. A. Pomeransky 《Communications in Mathematical Physics》1983,91(4):529-541
We consider a conformal invariant formulation of quantum electrodynamics. Conformal invariance is achieved with a specific mathematical construction based on the indecomposable representations of the conformal group associated with the electromagnetic potential and current. As a corollary of this construction modified expressions for the 3-point Green functions are obtained which both contain transverse parts. They make it possible to formulate a conformal invariant skeleton perturbation theory. It is also shown that the Euclidean Maxwell equations in conformal electrodynamics are manifestations of its kinematical structure: in the case of the 3-point Green functions these equations follow (up to constants) from the conformal invariance while in the case of higher Green functions they are equivalent to the equality of the kernels of the partial wave expansions. This is the manifestation of the mathematical fact of a (partial) equivalence of the representations associated with the potential, current and the field tensor. 相似文献
134.
S. V. Kozhevnikov V. D. Zhaketov A. V. Petrenko M. V. Bulavin A. Ye. Verkhoglyadov S. A. Kulikov Ye. P. Shabalin 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2016,10(1):1-9
Examples of the application of a cryogenic moderator in the REMUR time-of-flight neutron reflectometer of the IBR-2 pulsed reactor (Dubna) are given. The results of two experiments are presented: spatial beam splitting upon reflection from a magnetically noncollinear film and the recording of a microbeam formed by a layered waveguide. A conclusion concerning the efficiency of the cryogenic moderator for experiments of this type is made. 相似文献
135.
I. A. Leonidov E. I. Konstantinova M. V. Patrakeev V. L. Kozhevnikov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2016,90(11):2123-2128
The chemical potential of oxygen ΔμO relative to its standard state in the gas phase was calculated from the experimental dependences of the oxygen content in various polymorphic modifications of Ca0.9Pr0.1MnO3–δ on the partial pressure and temperature. The partial molar enthalpy \(\Delta {\overline H _O}\) and entropy \(\Delta {\overline S _O}\) of oxygen were obtained from the linear temperature dependences of ΔμO. Based on the ideal solution approximation, \(\Delta {\overline H _O}\) and \(\Delta {\overline S _O}\) were correlated with the enthalpies and entropies of the defect formation reactions, the concentrations of manganese cations, and the oxygen nonstoichiometry. The thermal excitation of Mn4+ cations was shown to substantially affect the thermodynamic functions of oxygen. 相似文献
136.
V. M. Zainullina M. A. Korotin V. L. Kozhevnikov 《Russian Journal of Electrochemistry》2007,43(5):570-575
Using the first-principle nonempirical linear muffin-tin orbital method in the tight-binding approximation (TB-LMTO) to the LSDA + U approximation, the electronic and magnetic structures and defect formation in strontium ferrite Sr3Fe2O6 are studied. It is found that Sr3Fe2O6 is a G type antiferromagnetic with the semiconductor electronic structure. The calculated band gap of 1.82 eV agrees well with experimental value (~2 eV). The ferrite spectrum corresponds to that of a semiconductor with a band gap of charge transfer. Iron ions in Sr3Fe2O6 are in a high-spin state and have configuration t 2g ↑3 e g ↑2 e g ↓1 . The calculated local magnetic moment on the iron ions is 3.9 μB. The presence of iron ions with a magnetic moment approaching 4 μB in Sr3Fe2O6 is explained by strong hybridization of 3d orbitals of iron and 2p orbitals of oxygen. The high-spin state of iron ions is described by d 5 + d 6 L states with predominant contribution d 6L, where L is a hole on oxygen. Based on ab initio LSDA + U calculations, various types and configurations of defects in the oxygen sublattice (oxygen vacancies, anti-Frenkel defects) are studied and a model for ionic transport in Sr3Fe2O6 is proposed. 相似文献
137.
New functionalized phenylpyridine ligands and their derived heteroleptic cyclometalated Ir(III) complexes have been synthesized. The complexes possess a combination of important properties: (i) blue emission, (ii) good photoluminescence quantum yields, and (iii) good solubility in organic solvents, making them very attractive as phosphorescent dopant emitters for solution-processable light-emitting devices. 相似文献
138.
Mikhail V. Patrakeev Ilia A. Leonidov Victor L. Kozhevnikov 《Journal of Solid State Electrochemistry》2011,15(5):931-954
This article gives a brief overview of the modern methods for in situ studying of oxygen non-stoichiometry in oxides. The
emphasis is on the techniques that are based on the use of transport properties of solid electrolytes with unipolar oxygen
ion conductivity, as well as on the experimental implementation of coulometric titration. The possible sources of experimental
errors are considered, and methods are discussed of their accounting and minimization. Several examples are given of the using
of the data on non-stoichiometry for the determination of thermodynamic properties and defect structure in oxides. 相似文献
139.
Neutron waveguides are three-layer thin-film structures which transform part of a collimated (with an angular divergence of
0.01°) and relatively wide (0.1 mm) incident neutron beam into a narrow (0.1 μm wide) and divergent (0.1°) beam at the output.
This submicron beam (which cannot be obtained using conventional focusing elements) is promising for studying nanostructures.
We propose a combination of a polarized-neutron reflectometer and a nonmagnetic (independent of the neutron spin) waveguide
for experiments employing polarized neutron beams with a submicron spatial resolution. This scheme can be applied, for example,
for position-sensitive studies of magnetic nanostructures. 相似文献
140.
P. A. Kozhevnikov 《代数通讯》2013,41(7):2628-2644
For every sufficiently large odd p, we present a continual set of nonfinitely based varieties of groups of exponent p. The properties of these varieties make it possible to answer some open questions on varieties of groups. 相似文献