全文获取类型
收费全文 | 155篇 |
免费 | 31篇 |
国内免费 | 7篇 |
专业分类
化学 | 25篇 |
力学 | 1篇 |
数学 | 1篇 |
物理学 | 148篇 |
综合类 | 18篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 12篇 |
2019年 | 18篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 13篇 |
2015年 | 10篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 7篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 2篇 |
2007年 | 1篇 |
2006年 | 8篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 1篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有193条查询结果,搜索用时 31 毫秒
21.
22.
We study the topological properties of a one-dimensional (1D) hardcore Bose-Fermi mixture using the exact diagonalization method. We firstly add a hardcore boson to a fermionic system and by examining the edge states we find that the quasi-particle manifests the topological properties of the system. Then we study a mixture with 7 fermions and 1 boson. We find that the mixture also exhibits topological properties and its behaviors are similar to that of the corresponding fermionic system. We present a qualitative explanation to understand such behaviors using the mapping between a hardcore boson and a spinless fermion. These results show the existence of topological properties in a 1D hardcore Bose-Fermi mixture and may be realized using cold atoms trapped in optical lattices experimentally. 相似文献
23.
李成德 《中南民族大学学报(自然科学版)》2014,(4):70-77
介绍了拓扑绝缘体与量子霍尔效应"家族"的关系和由来,并且从轴子模型的起源角度探讨了三维拓扑绝缘体的磁电耦合效应与冷暗物质轴子模型的联系与区别.结果表明:它们的联系在于材料的电子能带结构和QCD真空结构在拓扑特性上相似,因而有相似的电磁响应;但二者的物理起源不同,有关提议的用磁性拓扑绝缘体(TMI)测暗物质轴子的实验探测的轴子应该是外来的而非TMI产生的. 相似文献
24.
An exciton gas on a lattice is analysed in terms of a convergent hopping expansion. For a given chemical potential, our calculation provides a sufficient condition for the hopping rate to obtain an exponential decay of the exciton correlation function. This result indicates the existence of a Mott phase in which strong fluctuations destroy the long range correlations in the exciton gas at any temperature, either by thermal or by quantum fluctuations. 相似文献
25.
A. Milekhin N.P. Stepina A.I. Yakimov A.I. Nikiforov S. Schulze D.R.T. Zahn 《The European Physical Journal B - Condensed Matter and Complex Systems》2000,16(2):355-359
Self-organised Ge dot superlattices grown by molecular beam epitaxy of Ge and Si layers utilizing Stranski-Krastanov growth
mode were investigated by Raman spectroscopy. An average size of Ge quantum dots was obtained from transmission electron microscopy
measurements. The strain and interdiffusion of Ge and Si atoms in Ge quantum dots were estimated from the analysis of frequency
positions of optical phonons observed in the Raman spectra. Raman scattering by folded longitudinal acoustic phonons in the
Ge dot superlattices was observed and explained using of elastic continuum theory.
Received 25 January 2000 相似文献
26.
Conventional design of radiation detectors uses sintered ceramic insulating modules. The major drawback of these ceramic components
is their inherent brittleness. Ion chambers, in which these ceramic spacers are replaced by metallic components with plasma
spray coated alumina, have been developed in our Research Centre. These components act as thin spacers that have good mechanical
strength as well as high electrical insulation and replace alumina insulators with the same dimensions. As a result, the design
of the beam loss monitor ion chamber for CAT could be simplified by coating the outer surface of the HT electrode with alumina.
One of the chambers developed for isotope calibrator for brachytherapy gamma sources has its outer aluminium electrode (60
mm dia × 220 mm long) coated with 250 μ thick alumina (97%) + titania (3%).
In view of potential applications in neutron-sensitive ion chambers used in reactor control instrumentation, studies were
carried out on alumina 100 μ to 500 μ thick coatings on copper, aluminium and SS components. The electrical insulation varied
from 108 ohms to 1012 ohms for coating thicknesses above 200 μ. The porosity in the coating resulted in some fall in electrical insulation due
to moisture absorption. An improvement could be achieved by providing the ceramic surface with moisture-repellent silicone
oil coating. Irradiation at Apsara reactor core location showed that the coating on aluminium was found to be unaffected after
exposure to 1017 nvt fluence. 相似文献
27.
过渡金属碳化物和氮化物也被称为MXenes材料,是一类具有独特性质的新型二维材料.经第一性原理计算发现,二维Ta4C3O2的电子结构可能具有拓扑性质,而Ta4C3已被成功制备,Ta4C3O2可通过表面功能化实现制备.这些结果将为研究MXenes材料的拓扑性质提供有利借鉴,也为今后的实际应用奠定基础. 相似文献
28.
29.
纤维增强复合材料具有轻质、高强、耐蚀、绝缘、环保等性能,在电力行业输配电网络中已有广泛应用。综述了纤维增强复合材料在电网中的应用,主要包括复合绝缘子、复合材料杆塔、复合材料电力金具、碳纤维复合材料芯导线及复合材料电力安全工器具等。分析表明,纤维增强复合材料性能优良,能够满足现行环保节能新要求,未来具有巨大发展潜力。 相似文献
30.
We review the recent experimental progress towards observing quantum spin Hall effect in inverted InAs/GaSb quantum wells (QWs). Low temperature transport measurements in the hybridization gap show bulk conductivity of a non-trivial origin, while the length and width dependence of conductance in this regime show strong evidence for the existence of helical edge modes proposed by Liu et al. [Phys. Rev. Lett., 2008, 100: 236601]. Surprisingly, edge modes persist in spite of comparable bulk conduction and show only weak dependence on magnetic field. We elucidate that seeming independence of edge on bulk transport comes due to the disparity in Fermi-wave vectors between the bulk and the edge, leading to a total internal reflection of the edge modes. 相似文献