全文获取类型
收费全文 | 154篇 |
免费 | 0篇 |
国内免费 | 1篇 |
专业分类
化学 | 50篇 |
力学 | 3篇 |
数学 | 24篇 |
物理学 | 78篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 4篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 4篇 |
2012年 | 3篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 4篇 |
2008年 | 5篇 |
2007年 | 8篇 |
2006年 | 5篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 3篇 |
2002年 | 5篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1998年 | 1篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 10篇 |
1994年 | 7篇 |
1993年 | 10篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 8篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有155条查询结果,搜索用时 140 毫秒
71.
72.
The investigation of strain-rate effects on the mechanical response and characteristics of thin free-standing films is crucial for the design and fabrication of more reliable MEMS devices. It is also of high interest from the scientific and materials engineering views. In this paper we present a novel apparatus and a procedure for tensile testing of thin free-standing films under a wide range of strain rates from quasistatic to high, almost comparable with those obtained in Hopkinson bar tests. To provide this capability, a unique displacement measurement method is applied and a micro device which meets several strict requirements is implemented. We describe recent results of quasistatic experiments performed on pure aluminum free-standing thin films. A high rate experiment which demonstrates the setup capabilities is also presented. The micro-device measured properties are compared with finite element analysis results. 相似文献
73.
Quan-Quan Zhou You-Quan Zou Yehoshoa Ben-David Prof. David Milstein 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(67):15487-15490
Liquid organic hydrogen carriers (LOHCs) are powerful systems for the efficient unloading and loading molecular hydrogen. Herein, a liquid-to-liquid organic hydrogen carrier system based on reversible dehydrogenative coupling of ethylene glycol (EG) with ethanol catalysed by ruthenium pincer complexes is reported. Noticeable advantages of the current LOHC system is that both reactants (hydrogen-rich components) and the produced esters (hydrogen-lean components) are liquids at room temperature, and the dehydrogenation process can be performed under solvent and base-free conditions. Moreover, the hydrogenation reaction proceeds under low hydrogen pressure (5 bar), and the LOHC system has a relatively high theoretical gravimetric hydrogen storage capacity (HSC>5.0 wt %), presenting an attractive hydrogen storage system. 相似文献
74.
Ben-David Makhluf S Qasem R Rubinstein S Gedanken A Breitbart H 《Langmuir : the ACS journal of surfaces and colloids》2006,22(23):9480-9482
The spontaneous loading of magnetite nanoparticles into sperm cell was carried out by mixing an aqueous colloidal solution of Fe3O4-PVA with sperm cells (10(8) cells/ml) for 2 h at 37 degrees C suspended in glucose-free modified Tyrode solution. The penetration of the magnetite nanoparticles into the sperm cells was monitored by conventional analytical chemistry. We have demonstrated that the motility and the ability to undergo the acrosome reaction (i.e., the ability to fertilize the egg) were not affected by the presence of the magnetite nanoparticles. 相似文献
75.
Shai Ben-David 《Israel Journal of Mathematics》1978,31(3-4):394-394
76.
77.
This paper entails the development of bound equations on the number of minimized fuzzy switching functions. A triangular matrix representing the transitivity between fundamental fuzzy phrases is discussed and applied in the enumeration process. Improved upper and lower bounds have been developed by use of the transitivity matrix. In addition, an algorithm is described to calculate the number of distinct fuzzy switching functions for any number of variables. 相似文献
78.
Using heuristic arguments and numerical simulations it is argued that the critical exponent nu describing the localization length divergence at the integer quantum-Hall transition is modified in the presence of spin-orbit scattering with short-range correlations. The exponent is very close to nu=4/3, the percolation correlation length exponent, consistent with the prediction of a semiclassical argument. In addition, a band of weakly localized states is conjectured. 相似文献
79.
Kondo tunneling reveals hidden SO(n) dynamical symmetries of evenly occupied quantum dots. As is exemplified for an experimentally realizable triple quantum dot in parallel geometry, the possible values n=3,4,5,7 can be easily tuned by gate voltages. Following construction of the corresponding o(n) algebras, scaling equations are derived and Kondo temperatures are calculated. The symmetry group for a magnetic field induced anisotropic Kondo tunneling is SU(2) or SO(4). 相似文献
80.
When an asymmetric double dot is hybridized with itinerant electrons, its singlet ground state and lowly excited triplet state cross, leading to a competition between the Zhang-Rice mechanism of singlet-triplet splitting in a confined cluster and the Kondo effect (which accompanies the tunneling through quantum dot under a Coulomb blockade restriction). The rich physics of an underscreened S = 1 Kondo impurity in the presence of low-lying triplet-singlet excitations is exposed and estimates of the magnetic susceptibility and the electric conductance are presented, together with applications for molecule chemisorption on metallic substrates. 相似文献