全文获取类型
收费全文 | 254篇 |
免费 | 6篇 |
专业分类
化学 | 96篇 |
晶体学 | 1篇 |
力学 | 1篇 |
数学 | 43篇 |
物理学 | 119篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 3篇 |
2018年 | 3篇 |
2017年 | 8篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 9篇 |
2011年 | 11篇 |
2010年 | 11篇 |
2009年 | 15篇 |
2008年 | 11篇 |
2007年 | 15篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 9篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有260条查询结果,搜索用时 421 毫秒
81.
82.
A. M. Belonogov N. M. Mikhailov V. M. Lisitsyn V. V. Larionov L. S. Derevyagina L. M. Butkevich A. M. Nemchenko V. A. Lukin A. A. Solov'ev V. V. Tikhomirov V. V. Kisel'nik A. I. Toryanik N. A. Dolinin N. D. Tokarev A. A. Zhaksylykova A. N. Kravets I. Ya. Melik-Gaikazyan A. P. Savitskii I. S. Chukhlantseva Yu. P. Bulatov S. I. Masharov N. M. Rybalko A. G. Vaisburd D. I. Vaisburd I. D. Grigor'eva A. I. Fedosov A. S. Tonkoshkur N. I. Zimin Yu. L. Pivovarov 《Russian Physics Journal》1977,20(10):1390-1397
83.
84.
S. V. Alekseenko V. M. Dulin M. P. Tokarev D. M. Markovich 《Thermophysics and Aeromechanics》2016,23(2):301-304
The paper reports on shape of a three-dimensional coherent structure in a velocity field of a high-swirl turbulent jet with the bubble-type vortex breakdown. A set of the 3D instantenous velocity fields was measured by using the tomographic particle image velocimetry (tomographic PIV) technique and processed by the proper orthogonal decomposition (POD) method. The detected intensive coherent velocity component corresponded to a helical vortex core of the swirling jet and two secondary spiral vortices. The entire coherent structure was rotating around the jet axis in compliance with the direction of the flow swirl. From the 3D data it is concluded that the dynamics of the strsucture can be described by a traveling wave equation: Re[A(y, r)·e i(mθ + ky - ωt)] with the number of the spiral mode m = +1 for positively defined k and ω. 相似文献
85.
Liubov V. Sokolenko Yurii L. Yagupolskii Liliia S. Kumanetska Jérôme Marrot Emmanuel Magnier Volodimir O. Lipetskij Ihor V. Kalinin 《Tetrahedron letters》2017,58(13):1308-1311
Methyl 3-(dimethylamino) acrylates containing trifluoromethylsulfenyl-, trifluoromethylsulfinyl-, and trifluoromethylsulfonyl groups were synthesized and their utility demonstrated by reactions with aliphatic and aromatic amidines to produce 2,5-substituted 4(3H)-pyrimidones. Cyclization reactions of enaminones with urea or thiourea led to 5-substituted uracil or 2-thiouracil derivatives, respectively. 相似文献
86.
Ihor Studenyak Yuriy Neimet Csaba Cserháti Sándor K?kényesi Edvardas Kazakevi?ius Tomas ?alkus Algimantas Ke?ionis Antanas Orliukas 《Central European Journal of Physics》2012,10(1):206-209
Structural studies of (Ag3AsS3)
x
(As2S3)1−x
chalcogenide superionic glasses in the compositional range x = 0.3–0.9 were performed by scanning electron microscopy. Temperature and compositional dependences of transmission coefficient,
electrical conductivity, and activation energy were investigated 相似文献
87.
Self-similarity in high-energy multiparticle production processes is discussed. A parton shower and hadronization are assumed to give rise to a set of particle with a fractal structure. It is noted that the box counting (BC) and P-adic coverage (PaC) methods determine the fractal dimension with permissible 1/k ranges. A new method of systems of equations of P-adic coverages (SePaC) is proposed that extends the PaC method to fractals with permissible m/k ranges. The SePaC method is shown to determine the fractal dimension of a shower with a prescribed accuracy, the number of fractal levels, the type of the cascade (random or regular), and its structure. 相似文献
88.
Yu. V. Tokarev 《Radiophysics and Quantum Electronics》2009,52(1):1-12
We derived analytical expressions for the Stokes parameters of the “Sura” facility radiation. Results of the first experiments
on studying the linearly polarized components of the facility radiation on oblique paths by the method of reception of signals
on remote spacecraft are presented. The dominant contribution of the plasmasphere into the rotation measure of the radio-wave
polarization plane in near-Earth space is noted.
Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 52, No. 1, pp. 1–13, January 2009. 相似文献
89.
The average particle multiplicity density dN
ch/dη is the dynamical quantity that reflects some regularities of particle production in the low-p
T
range. The quantity is an important ingredient of z scaling. Experimental results on charged particle density are available for pp, pA, and AA collisions, while experimental properties of the jet density are still an open question. The goal of this work is to find
the variable that will reflect the main features of the jet production in a low transverse energy range and play the role
of the scale factor for the scaling function ψ(z) and variable z in data z-presentation. The appropriate candidate is the variable we called “scaled jet energy density.” The scaled jet energy density
is the probability of having a jet with defined E
T
in defined x
T
and pseudorapidity regions. The PYTHIA6.2 Monte Carlo generator is used for calculation of the scaled jet energy density
in proton-proton collisions over a high energy range
and at η = 0. The properties of the new variable are discussed and sensitivity to “physical scenarios” applied in the standard
Monte Carlo generator is noted. The results of the calculations of scaled jet energy density at LHC energies are presented
and compared with predictions based on z scaling.
The text was submitted by the authors in English. 相似文献
90.
Svetlana Ushcats Mykhailo Ushcats Leonid Bulavin Oksana Svechnikova Ihor Mykheliev 《Pramana》2018,90(3):31
In this article, a simple autonomous transiently chaotic flow with cubic nonlinearities is proposed. This system represents some unusual features such as having a surface of equilibria. We shall describe some dynamical properties and behaviours of this system in terms of eigenvalue structures, bifurcation diagrams, time series, and phase portraits. Various behaviours of this system such as periodic and transiently chaotic dynamics can be shown by setting special parameters in proper values. Our system belongs to a newly introduced category of transiently chaotic systems: systems with hidden attractors. Transiently chaotic behaviour of our proposed system has been implemented and tested by the OrCAD-PSpise software. We have found a proper qualitative similarity between circuit and simulation results. 相似文献