全文获取类型
收费全文 | 5599篇 |
免费 | 467篇 |
国内免费 | 341篇 |
出版年
2023年 | 61篇 |
2022年 | 62篇 |
2021年 | 255篇 |
2020年 | 202篇 |
2019年 | 230篇 |
2018年 | 220篇 |
2017年 | 188篇 |
2016年 | 278篇 |
2015年 | 360篇 |
2014年 | 443篇 |
2013年 | 452篇 |
2012年 | 479篇 |
2011年 | 429篇 |
2010年 | 263篇 |
2009年 | 232篇 |
2008年 | 276篇 |
2007年 | 233篇 |
2006年 | 172篇 |
2005年 | 129篇 |
2004年 | 138篇 |
2003年 | 124篇 |
2002年 | 113篇 |
2001年 | 101篇 |
2000年 | 89篇 |
1999年 | 98篇 |
1998年 | 71篇 |
1997年 | 63篇 |
1996年 | 42篇 |
1995年 | 55篇 |
1994年 | 57篇 |
1993年 | 56篇 |
1992年 | 69篇 |
1991年 | 54篇 |
1990年 | 39篇 |
1989年 | 31篇 |
1988年 | 30篇 |
1987年 | 21篇 |
1986年 | 18篇 |
1985年 | 26篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 20篇 |
1978年 | 11篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 7篇 |
1971年 | 5篇 |
排序方式: 共有6407条查询结果,搜索用时 15 毫秒
1.
Ji Guo Su Xiao Ming Han Xiao Zhang Yan Xue Hou Jian Zhuo Zhu Yi Dong Wu 《Journal of biomolecular structure & dynamics》2016,34(3):560-571
Protein collective motions play a critical role in many biochemical processes. How to predict the functional motions and the related key residue interactions in proteins is important for our understanding in the mechanism of the biochemical processes. Normal mode analysis (NMA) of the elastic network model (ENM) is one of the effective approaches to investigate the structure-encoded motions in proteins. However, the motion modes revealed by the conventional NMA approach do not necessarily correspond to a specific function of protein. In the present work, a new analysis method was proposed to identify the motion modes responsible for a specific function of proteins and then predict the key residue interactions involved in the functional motions by using a perturbation approach. In our method, an internal coordinate that accounts for the specific function was introduced, and the Cartesian coordinate space was transformed into the internal/Cartesian space by using linear approximation, where the introduced internal coordinate serves as one of the axes of the coordinate space. NMA of ENM in this internal/Cartesian space was performed and the function-relevant motion modes were identified according to their contributions to the specific function of proteins. Then the key residue interactions important for the functional motions of the protein were predicted as the interactions whose perturbation largely influences the fluctuation along the internal coordinate. Using our proposed methods, the maltose transporter (MalFGK2) from E. Coli was studied. The functional motions and the key residue interactions that are related to the channel-gating function of this protein were successfully identified. 相似文献
2.
3.
Phenotypes of inter-alpha-trypsin-inhibitor (ITI) have been determined by isoelectric focusing on polyacrylamide gels followed by immunofixation. The phenotype frequencies of ITI in the Han population in Chengdu, P. R. China have been investigated using this method. In addition, family studies have been conducted in 21 families. The results show that ITI is polymorphic in the Han population in Chengdu, China. The allele frequencies are as follows: ITI*1 = 0.5763. ITI*2 = 0.4107, ITI*3 = 0.0130. ITI is thus a new and promising genetic marker that can be used in the field of forensic haematogenetics. 相似文献
4.
5.
6.
7.
Shu Ge Fukun Shi Guiyao Zhou Songhao Liu Zhiyun Hou Lu Peng 《Plasmonics (Norwell, Mass.)》2016,11(5):1307-1312
A surface plasmon resonance sensor based on a U-shaped photonic crystal fiber with a rectangular lattice has been designed through finite element method. The U-shaped fiber exhibits not only stronger mechanical strength but also better sensor performance than our previous scheme. The upper detection limit extends to higher analyze refractive index, 1.384, for phase interrogation. We introduce a ratio to evaluate the impact of higher order plasmonic mode. For wavelength modulation scheme, the parameter to describe the performance of a sensor is chosen to be the figure of merit, which can be up to 533.8[RIU?1] around complete coupling condition. 相似文献
8.
Plant and Soil - Seeds are involved in the transmission of microorganisms from one plant generation to the next, acting as initial inoculum for the plant microbiome, therefore provide a key source... 相似文献
9.
10.