全文获取类型
收费全文 | 177篇 |
免费 | 6篇 |
国内免费 | 2篇 |
专业分类
化学 | 119篇 |
晶体学 | 3篇 |
力学 | 3篇 |
数学 | 35篇 |
物理学 | 25篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 6篇 |
2017年 | 12篇 |
2016年 | 10篇 |
2015年 | 7篇 |
2014年 | 8篇 |
2013年 | 10篇 |
2012年 | 18篇 |
2011年 | 11篇 |
2010年 | 8篇 |
2009年 | 6篇 |
2008年 | 14篇 |
2007年 | 9篇 |
2006年 | 7篇 |
2005年 | 7篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 6篇 |
2000年 | 2篇 |
1998年 | 1篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1938年 | 1篇 |
排序方式: 共有185条查询结果,搜索用时 171 毫秒
181.
182.
183.
Yavuz Kysal amil Ik Emine DogÜda Birsen Tozkoparan Mevlüt Ertan 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(5):o356-o357
The title compound, C25H17F2N3OS, was synthesized from 6‐(benzylidene)thiazolo[3,2‐b][1,2,4]triazol‐5(6H)‐one. The fused thiazolo[3,2‐b][1,2,4]triazole system is essentially planar, and bifurcated C—H⋯O, C—H⋯N and C—H⋯F interactions are present between molecules. 相似文献
184.
We theoretically investigate the electronic properties of p-type δ-doped GaAs inserted into a quantum well under the electric field, at T = 0 K. We will investigate the influence of the electric field on the δ-doping concentration for a uniform distribution. The depth of confining potential, the density profile, the Fermi level, the subband energies and the subband populations calculate by solving the Schrodinger and Poisson equations self consistently. It is found that the changes of the electronic properties are quite sensitive to the applied electric field and the doping concentration. As different from single n-type δ-doped structure, we see a replace between the ground light-hole (lh1 ) subband and the first excited heavy-hole (hh2) subband whenever the external electric field reaches a critical value. We find the abrupt changing of the subband energies and the subband populations whenever the applied electric field reaches a certain value. Also, it is found that the heavy-hole subbands contain many more energy states than the light-hole ones, the population of the heavy-hole levels represent approximately 91% of all the carriers. 相似文献
185.
We have developed a novel approach to obtain high metal sorption capacity utilizing a membrane containing chitosan and an immobilized reactive dye (i.e. Reactive Yellow-2). The composite membrane was characterized by SEM, FT-IR, swelling test, and elemental analysis. The membrane has uniform small pores distribution and the pore dimensions are between 5 and 10 μm, and the HEMA:chitosan ratio was 50:1. The reactive dye immobilized composite membrane was used in the removal of heavy metal ions [i.e., Pb(II), Hg(II) and Cd(II)] from aqueous medium containing different amounts of these ions (5-600 mg l−1) and at different pH values (2.0-7.0). The maximum adsorption capacities of heavy metal ions onto the composite membrane under non-competitive conditions were 64.3 mmol m−2 for Pb(II), 52.7 mmol m−2 for Hg(II), 39.6 mmol m−2 for Cd(II) and the affinity order was Pb(II) > Hg(II)>Cd(II). 相似文献