全文获取类型
收费全文 | 413078篇 |
免费 | 4570篇 |
国内免费 | 1269篇 |
专业分类
化学 | 205752篇 |
晶体学 | 5937篇 |
力学 | 19501篇 |
综合类 | 13篇 |
数学 | 59662篇 |
物理学 | 128052篇 |
出版年
2020年 | 2066篇 |
2019年 | 2025篇 |
2018年 | 11029篇 |
2017年 | 11911篇 |
2016年 | 7985篇 |
2015年 | 4245篇 |
2014年 | 4650篇 |
2013年 | 14221篇 |
2012年 | 15181篇 |
2011年 | 25796篇 |
2010年 | 15625篇 |
2009年 | 15533篇 |
2008年 | 22819篇 |
2007年 | 26382篇 |
2006年 | 12468篇 |
2005年 | 18332篇 |
2004年 | 13631篇 |
2003年 | 12201篇 |
2002年 | 10075篇 |
2001年 | 10268篇 |
2000年 | 8004篇 |
1999年 | 6178篇 |
1998年 | 4967篇 |
1997年 | 4765篇 |
1996年 | 4938篇 |
1995年 | 4466篇 |
1994年 | 4207篇 |
1993年 | 4009篇 |
1992年 | 4498篇 |
1991年 | 4363篇 |
1990年 | 4083篇 |
1989年 | 3898篇 |
1988年 | 4201篇 |
1987年 | 3867篇 |
1986年 | 3745篇 |
1985年 | 5396篇 |
1984年 | 5485篇 |
1983年 | 4452篇 |
1982年 | 4825篇 |
1981年 | 4867篇 |
1980年 | 4621篇 |
1979年 | 4751篇 |
1978年 | 4763篇 |
1977年 | 4670篇 |
1976年 | 4651篇 |
1975年 | 4553篇 |
1974年 | 4399篇 |
1973年 | 4603篇 |
1972年 | 2594篇 |
1971年 | 1896篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Yang T. L. Kao C. L. Kuo C. E. Yeh H. C. Li W. J. Li H. T. Chen C. Y. 《Chemistry of Natural Compounds》2022,58(5):825-827
Chemistry of Natural Compounds - A novel bibenzyl derivative, hydrangchinenin (1), was isolated from the stems of Hydrangea chinensis Maxim. (Hydrangeaceae). Its structure was determined on the... 相似文献
2.
Experimental Mechanics - Temperature gradients significantly affect the material fatigue process. A reliable and robust test procedure is needed for quantifying the effects of temperature gradients... 相似文献
3.
Machado J. A. Tenreiro Rocha-Neves J. M. Azevedo Filipe Andrade J. P. 《Nonlinear dynamics》2021,106(2):1525-1555
Nonlinear Dynamics - Given a data-set of Ribonucleic acid (RNA) sequences we can infer the phylogenetics of the samples and tackle the information for scientific purposes. Based on current data and... 相似文献
4.
Kobayashi M. Zhang Y. Ishikawa H. Sun J. Oddershede J. Juul Jensen D. Miura H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such... 相似文献
5.
Laguel Yassine Pillutla Krishna Malick Jérôme Harchaoui Zaid 《Set-Valued and Variational Analysis》2021,29(4):967-996
Set-Valued and Variational Analysis - R. Tyrell Rockafellar and his collaborators introduced, in a series of works, new regression modeling methods based on the notion of superquantile (or... 相似文献
6.
7.
Li Y. Shi W. H. Dong L. M. Xu S. X. Huang H. J. Yin J. R. 《Journal of Applied Spectroscopy》2022,89(3):534-541
Journal of Applied Spectroscopy - Sr3B2O6:Dy3+, Eu3+ single-matrix white-light-emitting materials are prepared using the high-temperature solid-state method. The microstructure, emission spectrum,... 相似文献
8.
9.
Hongjin Wang Tengfei Long Hao Zhang Meng Li Qi Sun Xin Zhai Lixin Sun 《Biomedical chromatography : BMC》2022,36(4):e5301
3,4-Difluorobenzyl(1-ethyl-5-(4-((4-hydroxypiperidin-1-yl)-methyl)thiazol-2-yl)-1H-indol-3-yl)carbamate (NAI59), a small molecule with outstanding therapeutic effectiveness to anti-pulmonary fibrosis, was developed as an autotaxin inhibitor candidate compound. To evaluate the pharmacokinetics and plasma protein binding of NAI59, a UPLC–MS/MS method was developed to quantify NAI59 in plasma and phosphate-buffered saline. The calibration curve linearity ranged from 9.95 to 1990.00 ng/mL in plasma. The accuracy was −6.8 to 5.9%, and the intra- and inter-day precision was within 15%. The matrix effect and recovery, as well as dilution integrity, were within the criteria. The chromatographic and mass spectrometric conditions were also feasible to determine phosphate-buffered saline samples, and it has been proved that this method exhibits good precision and accuracy in the range of 9.95–497.50 ng/mL in phosphate-buffered saline. This study is the first to determine the pharmacokinetics, absolute bioavailability, and plasma protein binding of NAI59 in rats using this established method. Therefore, the pharmacokinetic profiles of NAI59 showed a dose-dependent relationship after oral administration, and the absolute bioavailability in rats was 6.3%. In addition, the results of protein binding showed that the combining capacity of NAI59 with plasma protein attained 90% and increased with the increase in drug concentration. 相似文献
10.
Restricted testing conditions were considered recently. For the maximal operator, Hytönen, Li and Sawyer [8] first obtained parental testing condition. Later, they [9] showed that it suffices to restrict testing to doubling cubes. Chen and Lacey [3] gave a similar restricted testing condition. In our paper, we discuss a version of the latter in the multilinear setting.
相似文献