全文获取类型
收费全文 | 327篇 |
免费 | 118篇 |
国内免费 | 29篇 |
专业分类
化学 | 53篇 |
晶体学 | 3篇 |
力学 | 34篇 |
综合类 | 2篇 |
数学 | 29篇 |
物理学 | 353篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 13篇 |
2021年 | 6篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 15篇 |
2016年 | 15篇 |
2015年 | 18篇 |
2014年 | 18篇 |
2013年 | 23篇 |
2012年 | 17篇 |
2011年 | 19篇 |
2010年 | 18篇 |
2009年 | 18篇 |
2008年 | 19篇 |
2007年 | 18篇 |
2006年 | 19篇 |
2005年 | 24篇 |
2004年 | 16篇 |
2003年 | 17篇 |
2002年 | 17篇 |
2001年 | 9篇 |
2000年 | 18篇 |
1999年 | 13篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1984年 | 3篇 |
1982年 | 3篇 |
1979年 | 1篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
排序方式: 共有474条查询结果,搜索用时 15 毫秒
301.
Characteristics of anomalous Hall effect in spin-polarized two-dimensional electron gases in the presence of both intrinsic, extrinsic, and external electric-field induced spin-orbit couplings 下载免费PDF全文
The various competing contributions to the anomalous Hall effect in spin-polarized two-dimensional electron gases in the presence of both intrinsic,extrinsic and external electric-field induced spin-orbit coupling were investigated theoretically.Based on a unified semiclassical theoretical approach,it is shown that the total anomalous Hall conductivity can be expressed as the sum of three distinct contributions in the presence of these competing spin-orbit interactions,namely an intrinsic contribution determined by the Berry curvature in the momentum space,an extrinsic contribution determined by the modified Bloch band group velocity and an extrinsic contribution determined by spin-orbit-dependent impurity scattering.The characteristics of these competing contributions are discussed in detail in the paper. 相似文献
302.
Francis Bern Michael Ziese Kathrin Dörr Andreas Herklotz Ionela Vrejoiu 《固体物理学:研究快报》2013,7(3):204-206
High quality orthorhombic and tetragonal SrRuO3 thin films were grown by pulsed laser deposition on SrTiO3(001) and Ba0.75Sr0.25TiO3 buffered LaAlO3(001) substrates. Resistivity vs. temperature curves showed a slope change at a Curie temperature of 147.5 ± 2 K for 40 nm thick films irrespective of crystalline symmetry. The Hall resistivity of both films contained an anomalous Hall contribution. The anomalous Hall coefficient was positive throughout the whole temperature range for the tetragonal film, whereas it showed a sign change at 143 K for the orthorhombic film. This is a strong indication that the Berry‐phase mechanism is the dominant anomalous Hall effect mechanism in SrRuO3. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
303.
This work deals with the determination of the various azeotropies in radical terpolymerization: unitary azeotropy (mi = Mi); binary azeotropy (mi/mj. = Mi/Mj), and ternary or true azeotropy (Mj = mj for j = 1, 2, 3). General analytical solutions are given which are easily handled by a computer. In addition, these calculations show the existence of pseudo-azeotropy where the deviation between polymer and monomer feed compositions is very small, not only at the beginning of the reaction, but also with increasing conversion. 相似文献
304.
305.
<正>The program OASIS4.0 has been released.Apart from the improved single-wavelength anomalous diffraction (SAD) phasing algorithm described in a separate paper,an important new feature in this version is the automation of the iterative phasing and model-building process in solving protein structures.A new graphical user's interface(GUI) is provided for controlling and real-time monitoring the dual-space iterative process.The GUI is discussed in detail in the present paper. 相似文献
306.
A study of intermittency of target associated fragments produced in the interactions of ~(16)O- AgBr at 4.5 AGeV/c with nuclear emulsion using the method of factorial moments, F_q,has been performed. The dependence of the moments on the number of bins M is found to follow a power law behavior for the experimental data in terms of new scaled variableχ(z)suggested by Bialas and Gazdzicki.The anomalous dimensions, d_q,increase linearly with the order of moments,q.This observation indicates the association of multifractility with production mechanism of target associated fragments. 相似文献
307.
利用激光脉冲在光纤光栅中传播时所遵守的相干耦合非线性薛定谔方程,研究了激光脉冲在局部高斯变迹布拉格光纤光栅中传输时,在反常色散区和正常色散区所产生的调制不稳定性。结果表明在反常色散区和正常色散区都能产生调制不稳定性;在反常色散区,当输入功率达到一定数值、传输距离一定时,当f=-1禁带之上能带底时,调制不稳定性增益的强度最强、宽度最窄;当远离能带底时强度减弱、宽度变宽;在正常色散区,在产生调制不稳定性功率区域,调制不稳定性存在并从给定值一直持续到无穷;并且,在反常色散区和在正常色散区,增益谱都受到局部高斯变迹函数的制约。 相似文献
308.
Exact Solutions of a Generalized Multi-Fractional Nonlinear Diffusion Equation in Radical Symmetry 总被引:1,自引:0,他引:1
This paper is devoted to investigating exact solutions of a generalized fractional nonlinear anomalous diffusion equation in radical symmetry. The presence of external force and absorption is also considered. We first investigate the nonlinear anomalous diffusion equations with one-fractional derivative and then multi-fractional ones. In both situations, we obtain the corresponding exact solutions, and the solutions found here can have a compact behavior or a long tailed behavior. 相似文献
309.
The extrinsic mechanism for anomalous Hall effect in ferromagnets is extended to include the contributions both from spin-orbit-dependent impurity scattering and from the spin-orbit coupling induced by external electric fields. The results obtained suggest that, within the framework of the extrinsic mechanisms, the anomalous Hall current in a ferromagnet may also contain a substantial amount of dissipationless contribution independent of impurity scattering. After the contribution from the spin-orbit coupling induced by external electric fields is included, the total anomalous Hall conductivity is about two times larger than that due to soin-orbit dependent impurity scatterings. 相似文献
310.
In modelling complex systems as real diffusion processes it is common to analyse its diffusive regime through the study of approximating sequences of random walks. For the partial sums one considers the approximating sequence of processes . Then, under sufficient smoothness requirements we have the convergence to the desired diffusion, . A key assumption usually presumed is the finiteness of the second moment, and, hence the validity of the Central Limit Theorem. Under anomalous diffusive regime the asymptotic behavior of S
n may well be non-Gaussian and . Such random walks have been referred by physicists as Lévy motions or Lévy flights. In this work, we introduce an alternative notion to classify these regimes, the diffusion index . For some properly chosen let . Relationship between , the infinitesimal diffusion coefficients and the diffusion constant will be explored. Illustrative examples as well as estimates, based on extreme order statistics, for will also be presented. 相似文献