全文获取类型
收费全文 | 138篇 |
免费 | 7篇 |
国内免费 | 9篇 |
专业分类
化学 | 5篇 |
力学 | 28篇 |
综合类 | 1篇 |
数学 | 67篇 |
物理学 | 19篇 |
无线电 | 34篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2020年 | 2篇 |
2019年 | 9篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 7篇 |
2013年 | 7篇 |
2012年 | 8篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 8篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 8篇 |
2005年 | 11篇 |
2004年 | 3篇 |
2003年 | 12篇 |
2002年 | 7篇 |
2000年 | 7篇 |
1999年 | 1篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1992年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有154条查询结果,搜索用时 15 毫秒
1.
2.
Silver halide (AgX) microcrystal was used as template to synthesize hollow polyelectrolyte capsules. These hollow capsules were characterized by laser light scattering (LLS) used to measure the size of the capsules in solution. The ratio of hydrodynamic radius (Rh) from dynamic LLS to the radius of gyration (Rg) from static LLS is almost unity, revealing that the entities are hollow in solution. The results suggest that the LLS method can be regarded as a good complement to the confocal laser scanning microscopy (CLSM) method for the characterization of small hollow capsules, and it possesses the advantage of not needing fluorescence labeling. 相似文献
3.
4.
We consider the q-hypergeometric equation with q
N = 1 and , , . We solve this equation on the space of functions given by a power series multiplied by a power of the logarithmic function. We prove that the subspace of solutions is two-dimensional over the field of quasi-constants. We get a basis for this space explicitly. In terms of this basis, we represent the q-hypergeometric function of the Barnes type constructed by Nishizawa and Ueno. Then we see that this function has logarithmic singularity at the origin. This is a difference between the q-hypergeometric functions with 0 < |q| < 1 and at |q| = 1. 相似文献
5.
A new group (linear) representation of the propagation of waves in properly and naturally gyrotropic crystals in the general case where the nonreciprocity effect takes place has been developed. Simple expressions of the dependence of ray (group) velocities and polarization vectors of isonormal waves on the complex vector of principal velocities dual to the unitary tensor by which the optical properties of crystals are directly characterized have been obtained. The relationship between gyrotropy and anisotropy and the dipole moment and displacement current induced by the radiation in the crystal has been established. It is shown that the presence of gyrotropy and nonlinear polarization of radiation together with the elimination of conical points entails a phase ambiguity of the ray velocity of the quantummechanical type and a smearing and layering of the wave surface, as well as a discreteness of the spectrum of velocity values of isonormal waves. 相似文献
6.
We define a set of cell modules for the extended affine Hecke algebra of type A which are parametrised by SLn()-conjugacy classes of pairs (s, N), where s SLn() is semisimple and N is a nilpotent element of the Lie algebra which has at most two Jordan blocks and satisfies Ad(s)·N=q
2
N. When q
2–1, each of these has irreducible head, and the irreducible representations of the affine Hecke algebra so obtained are precisely those which factor through its Temperley–Lieb quotient. When q
2=–1, the above remarks apply to a subset of the cell modules. Using our work on the cellular nature of those quotients, we are able to obtain complete information on the decomposition of the cell modules in all cases, even when q is a root of unity. They turn out to be multiplicity free, and the composition factors may be precisely described in terms of a partial order on the pairs (s, N). These results give explicit formulae for the dimensions of the irreducibles. Assuming our modules are identified with the standard modules earlier defined by Bernstein–Zelevinski, Kazhdan–Lusztig and others, our results may be interpreted as the determination of certain Kazhdan–Lusztig polynomials. [This has now been proved and will appear in a subsequent work of the authors.]The second author thanks the Australian Research Council and the Alexander von Humboldt Stiftung for support and the Universität Bielefeld for hospitality during the preparation of this work. 相似文献
7.
8.
爱因斯坦坚持场纲领的原因 总被引:5,自引:0,他引:5
探讨了爱因斯坦坚持场纲领的物理学认识基础和思想发展过程,分析了其坚持场纲领的目的及未获成功的原因。 相似文献
9.
In this Letter we show the existence of bidifferential structures on finite Hopf algebras, which arise from quantum groups at roots of unity. 相似文献
10.
T. P. Fries 《国际流体数值方法杂志》2009,60(4):437-471
In two‐fluid flows, jumps and/or kinks along the interfaces are present in the resulting velocity and pressure fields. Standard methods require mesh manipulations with the aim that either element edges align with the interfaces or that the mesh is sufficiently refined near the interfaces. In contrast, enriched methods, such as the extended finite element method (XFEM), enable the representation of arbitrary jumps and kinks inside elements. Thereby, optimal convergence can be achieved for two‐fluid flows with meshes that remain fixed throughout the simulation. In the intrinsic XFEM, in contrast to other enriched methods, no more unknowns are present in the approximation than in a standard finite element approximation. In this work, the intrinsic XFEM is employed for the simulation of incompressible two‐fluid flows. Numerical results are shown for a number of test cases and prove the success of the method. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献