全文获取类型
收费全文 | 136篇 |
免费 | 5篇 |
国内免费 | 3篇 |
学科分类
数理化 | 144篇 |
出版年
2023年 | 1篇 |
2021年 | 4篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 6篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 12篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 7篇 |
2009年 | 9篇 |
2008年 | 13篇 |
2007年 | 3篇 |
2006年 | 4篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 2篇 |
排序方式: 共有144条查询结果,搜索用时 0 毫秒
141.
Mir Ghasem Hosseini Masoud Faraji Mohamad Mohsen Momeni Sohrab Ershad 《Mikrochimica acta》2011,172(1-2):103-108
Catalytic nanotubes made from titanium dioxide (TiO2-NTs) and covered with gold nanoparticles (Au-NPs) were prepared via galvanic deposition of the Au-NPs on the TiO2-NTs. The morphology and surface characteristics of the resulting electrodes were investigated using scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results indicated that the Au-NPs were homogeneously deposited on the surface of TiO2-NTs which consist of individual tubes of about 40?C80?nm in diameter. The AuNPs with a size of 80?C100?nm are well-dispersed on the surface of the TiO2-NTs. The electro-catalytic activity of the electrodes towards the electro-oxidation of levodopa was studied by cyclic voltammetry, differential puls voltammetry. The results showed that the electrodes exhibit a considerably higher activity toward the oxidation of levodopa. The oxidation peak current linearly depends on the concentration of levodopa in the 10 to 70???M concentration range. Levodopa was determined by the method in pharmaceutical preparations, and results were found to be satisfactory. Figure
Comparison of cyclic voltammograms of Au?\TiO2?\NTs/Ti and a flat gold electrode for determination levodopa. 相似文献
142.
We have derived analytic expressions for the deflection as well as transmitted fraction of monochromatic neutrons forward
diffracted by a single crystal prism. In the vicinity of a Bragg reflection, the neutron deflection deviates sharply from
that for an amorphous prism, exhibiting three orders of magnitude greater sensitivity to the incidence angle. We have measured
the variation of neutron deflection and transmission across a Bragg reflection, for several single crystal prisms. The results
agree well with theory.
相似文献
143.
Gerd W. Rabe Sohrab Kheradmandan Louise M. Liable-Sands Ilia A. Guzei Arnold L. Rheingold 《Angewandte Chemie (International ed. in English)》1998,37(10):1404-1407
A coordination environment reminiscent of a paddle-wheel is exhibited by aryl groups about one of the two cesium ions in CsP(H)Dmp (Dmp=2,6-dimesitylphenyl; structure depicted on the right), which has now been synthesized and is found to exhibit Cs+{Cs2[P(H)Dmp]3}− contact ion pairs in the solid state. In contrast, the analogous rubidium compound displays a Rb4P4 cube as the central structural motif. 相似文献
144.
We consider the Cauchy problem for the Schrödinger maps evolution when the domain is the hyperbolic plane. An interesting feature of this problem compared to the more widely studied case on the Euclidean plane is the existence of a rich new family of finite energy harmonic maps. These are stationary solutions, and thus play an important role in the dynamics of Schrödinger maps. The main result of this article is the asymptotic stability of (some of) such harmonic maps under the Schrödinger maps evolution. More precisely, we prove the nonlinear asymptotic stability of a finite energy equivariant harmonic map under the Schrödinger maps evolution with respect to non-equivariant perturbations, provided obeys a suitable linearized stability condition. This condition is known to hold for all equivariant harmonic maps with values in the hyperbolic plane and for a subset of those maps taking values in the sphere. One of the main technical ingredients in the paper is a global-in-time local smoothing and Strichartz estimate for the operator obtained by linearization around a harmonic map, proved in the companion paper [36]. © 2021 Wiley Periodicals LLC. 相似文献