全文获取类型
收费全文 | 1959篇 |
免费 | 89篇 |
国内免费 | 26篇 |
专业分类
化学 | 1465篇 |
晶体学 | 25篇 |
力学 | 71篇 |
数学 | 205篇 |
物理学 | 308篇 |
出版年
2024年 | 15篇 |
2023年 | 30篇 |
2022年 | 150篇 |
2021年 | 116篇 |
2020年 | 76篇 |
2019年 | 74篇 |
2018年 | 73篇 |
2017年 | 52篇 |
2016年 | 104篇 |
2015年 | 58篇 |
2014年 | 70篇 |
2013年 | 107篇 |
2012年 | 133篇 |
2011年 | 148篇 |
2010年 | 94篇 |
2009年 | 93篇 |
2008年 | 85篇 |
2007年 | 81篇 |
2006年 | 67篇 |
2005年 | 64篇 |
2004年 | 45篇 |
2003年 | 29篇 |
2002年 | 34篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 9篇 |
1997年 | 17篇 |
1996年 | 17篇 |
1995年 | 14篇 |
1994年 | 5篇 |
1993年 | 20篇 |
1992年 | 7篇 |
1991年 | 10篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 17篇 |
1983年 | 6篇 |
1982年 | 10篇 |
1981年 | 6篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 8篇 |
1976年 | 7篇 |
1975年 | 7篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1965年 | 4篇 |
排序方式: 共有2074条查询结果,搜索用时 15 毫秒
971.
972.
Chromatographia - Herein we report two sensitive and accurate UHPLC and TLC-densitometric methods for the simultaneous determination of amprolium HCl, ethopabate, and sulfaquinoxaline-Na. A UHPLC... 相似文献
973.
The dynamic response of fully premixed flames stabilized in strongly swirled flows undergoing vortex breakdown is investigated with axisymmetric unsteady RANS simulations. The analysis relies on the well known Helmholtz-Hodge decomposition of the velocity field into its irrotational and rotational components. A novel methodology based on the linearization of the progress variable transport equation is developed to determine the separate contribution of these velocity components to the Flame Transfer Function (FTF). Due to the phase delay between the convected tangential velocity and instantaneously propagating axial velocity perturbations, a non-monotonic frequency dependence of the swirl number amplitude downstream the swirl generator is detected. In line with experimental observations, such non-monotonic frequency dependence is found also for the amplitude and phase of the FTF. This behaviour is associated here with rotational velocity perturbations generated by the Central Recirculation Zone (CRZ) generated by the phenomenon of vortex breakdown which, responding in a fashion totally similar to the swirl number perturbation, produces flame surface area fluctuations with the same distribution versus frequency. 相似文献
974.
975.
976.
977.
978.
Gökhan Sahin Fabe Idrissa Barro Moustapha Sané Prince Abdoul Aziz Honadia Adem Kocyigit Genber Kerimli 《Chinese Journal of Physics (Taipei)》2017,55(1):203-210
This paper investigates theoretically the performance of conversion efficiency of a bifacial silicon solar cell with particle irradiation. The bifaciality coefficient and the conversion efficiency are calculated for various rear side illumination conditions and electron fluence, taking into account the diffusion length related damage coefficient. The main purpose of the work is to show that irradiation could significantly degrade both the bifaciality coefficient and then the conversion efficiency of the bifacial solar cell and to exhibit the role of the fluence and rear side illumination condition level in the performance of the bifacial silicon solar cell. 相似文献
979.
980.
The synthesis is reported of new meta‐substituted quaterphenyls and several related dimers as dopants for nematic mixtures with flexoelectric properties. The number and nature of the terminal substituents is varied from apolar with a small dipole moment to polar with a strong dipole moment. The number of methylene units in the flexible aliphatic spacer between the polyfluorinated aromatic groups of the dimers is also varied. Dimers capable of banana‐shaped conformers induce an increase in the flexoelectric coefficients of mixtures containing them and reduce the clearing point to a small extent. 相似文献