全文获取类型
收费全文 | 13065篇 |
免费 | 1139篇 |
国内免费 | 831篇 |
出版年
2024年 | 18篇 |
2023年 | 158篇 |
2022年 | 336篇 |
2021年 | 630篇 |
2020年 | 437篇 |
2019年 | 476篇 |
2018年 | 473篇 |
2017年 | 354篇 |
2016年 | 517篇 |
2015年 | 753篇 |
2014年 | 943篇 |
2013年 | 971篇 |
2012年 | 1169篇 |
2011年 | 1038篇 |
2010年 | 721篇 |
2009年 | 598篇 |
2008年 | 701篇 |
2007年 | 724篇 |
2006年 | 607篇 |
2005年 | 539篇 |
2004年 | 503篇 |
2003年 | 398篇 |
2002年 | 377篇 |
2001年 | 228篇 |
2000年 | 187篇 |
1999年 | 185篇 |
1998年 | 106篇 |
1997年 | 95篇 |
1996年 | 90篇 |
1995年 | 75篇 |
1994年 | 74篇 |
1993年 | 65篇 |
1992年 | 82篇 |
1991年 | 69篇 |
1990年 | 48篇 |
1989年 | 57篇 |
1988年 | 38篇 |
1987年 | 37篇 |
1986年 | 29篇 |
1985年 | 34篇 |
1984年 | 13篇 |
1983年 | 22篇 |
1982年 | 15篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1973年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 156 毫秒
1.
2.
3.
4.
Xiuyun Ye Shigeru Yoshida T. B. Ng 《The international journal of biochemistry & cell biology》2000,32(11-12)
A mild and rapid method is described for isolating various milk proteins from bovine rennet whey. β-Lactoglobulin from bovine rennet whey was easily adsorbed on and desorbed from a weak anion exchanger, diethylaminoethyl-Toyopearl. However, α-lactalbumin could not be adsorbed onto the resin. α-Lactalbumin and β-lactoglobulin from rennet whey could also be adsorbed and separated using a strong anion exchanger, quaternary aminoethyl-Toyopearl. The rennet whey was passed through a strong cation exchanger, sulphopropyl-Toyopearl, to separate lactoperoxidase and lactoferrin. α-Lactalbumin and β-lactoglobulin were adsorbed onto quaternary aminoethyl-Toyopearl. α-Lactalbumin was eluted using a linear (0–0.15 M) concentration gradient of NaCl in 0.05 M Tris–HCl buffer (pH 8.5). Subsequently, β-lactoglobulin B and β-lactoglobulin A were eluted from the column with 0.05 M Tris–HCl (pH 6.8), using a linear (0.1–0.25 M) concentration gradient of NaCl. The yields were 1260 mg α-lactalbumin, 1290 mg β-lactoglobulin B and 2280 mg β-lactoglobulin A from 1 l rennet whey. 相似文献
5.
6.
Yang Su-Rong Sun Huan-Xin Hu Zhen-Zhen Wang Si-Heng Sun Hui Xue Yin-Jia Ye Chen-Bo 《Sleep and biological rhythms》2017,15(1):57-65
Sleep and Biological Rhythms - Chronic sleep deprivation (SD) is an overwhelming problem in young students. Firstly, we investigated whether different levels of pre-training SD had effects on... 相似文献
7.
Ye. P. Dulepova V. A. Nadtochii L. L. Budnikova 《Russian Journal of Marine Biology》2008,34(7):472-481
The trophic structure of benthic communities in the Sea of Okhotsk and Bering Sea was analyzed based on the results of macrobenthic
survey catches conducted in the Far Eastern seas in the 2000s. The production of trophic levels and entire communities was
determined. It was shown that production of benthic communities is still at a high level and has almost not changed since
the 1980s. The arrangement of the communities of some shelf areas by productivity characteristics was made. 相似文献
8.
In tumor metastasis, the margination and adhesion of tumor cells are two critical and closely related steps, which may determine the destination where the tumor cells extravasate to. We performed a direct three-dimensional simulation on the behaviors of the tumor cells in a real microvascular network, by a hybrid method of the smoothed dissipative particle dynamics and immersed boundary method (SDPD-IBM). The tumor cells are found to adhere at the microvascular bifurcations more frequently, and there is a positive correlation between the adhesion of the tumor cells and the wall-directed force from the surrounding red blood cells (RBCs). The larger the wall-directed force is, the closer the tumor cells are marginated towards the wall, and the higher the probability of adhesion behavior happen is. A relatively low or high hematocrit can help to prevent the adhesion of tumor cells, and similarly, increasing the shear rate of blood flow can serve the same purpose. These results suggest that the tumor cells may be more likely to extravasate at the microvascular bifurcations if the blood flow is slow and the hematocrit is moderate. 相似文献
9.
10.