全文获取类型
收费全文 | 106712篇 |
免费 | 21906篇 |
国内免费 | 11487篇 |
专业分类
化学 | 89859篇 |
晶体学 | 1397篇 |
力学 | 5307篇 |
综合类 | 719篇 |
数学 | 10865篇 |
物理学 | 31958篇 |
出版年
2024年 | 168篇 |
2023年 | 1396篇 |
2022年 | 2010篇 |
2021年 | 2664篇 |
2020年 | 3956篇 |
2019年 | 5129篇 |
2018年 | 3426篇 |
2017年 | 3116篇 |
2016年 | 6479篇 |
2015年 | 6760篇 |
2014年 | 7509篇 |
2013年 | 9338篇 |
2012年 | 9450篇 |
2011年 | 9044篇 |
2010年 | 7675篇 |
2009年 | 7634篇 |
2008年 | 7573篇 |
2007年 | 6263篇 |
2006年 | 5784篇 |
2005年 | 5028篇 |
2004年 | 4133篇 |
2003年 | 3495篇 |
2002年 | 4146篇 |
2001年 | 3110篇 |
2000年 | 2868篇 |
1999年 | 1851篇 |
1998年 | 1302篇 |
1997年 | 1219篇 |
1996年 | 1155篇 |
1995年 | 986篇 |
1994年 | 917篇 |
1993年 | 723篇 |
1992年 | 643篇 |
1991年 | 516篇 |
1990年 | 489篇 |
1989年 | 364篇 |
1988年 | 306篇 |
1987年 | 251篇 |
1986年 | 246篇 |
1985年 | 226篇 |
1984年 | 150篇 |
1983年 | 115篇 |
1982年 | 82篇 |
1981年 | 63篇 |
1980年 | 40篇 |
1979年 | 39篇 |
1978年 | 29篇 |
1977年 | 23篇 |
1976年 | 18篇 |
1974年 | 17篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
Miao Xiu-feng Xu Yao-qun Yao Feng-ge 《International Journal of Theoretical Physics》2021,60(7):2604-2612
International Journal of Theoretical Physics - This paper mainly studied the observer design of Lipschitz stochastic discrete system. For the first time, generalized Lipschitz conditions are... 相似文献
13.
Nonlinear Dynamics - The classical Kuramoto model serves as a useful tool for studying synchronization transitions in coupled oscillators that is limited to the sinusoidal and pairwise... 相似文献
14.
A numerical model was developed and validated to investigate the fluid–structure interactions between fully developed pipe flow and core–shell-structured microcapsule in a microchannel. Different flow rates and microcapsule shell thicknesses were considered. A sixth-order rotational symmetric distribution of von Mises stress over the microcapsule shell can be observed on the microcapsule with a thinner shell configuration, especially at higher flow rate conditions. It is also observed that when being carried along in a fully developed pipe flow, the microcapsule with a thinner shell tends to accumulate stress at a higher rate compared to that with a thicker shell. In general, for the same microcapsule configuration, higher flow velocity would induce a higher stress level over the microcapsule shell. The deformation gradient was used to capture the microcapsule's deformation in the present study. The effect of Young's modulus on the microcapsule shell on the microcapsule deformation was investigated as well. Our findings will shed light on the understanding of the stability of core–shell-structured microcapsule when subjected to flow-induced shear stress in a microfluidic system, enabling a more exquisite control over the breakup dynamics of drug-loaded microcapsule for biomedical applications. 相似文献
15.
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
16.
Yi-Tong Xu Tian-Yang Zhang Zheng Li Xiang-Nan Liu Yuan-Cheng Zhu Wei-Wei Zhao Hong-Yuan Chen Jing-Juan Xu 《Electroanalysis》2022,34(6):947-955
Photoelectrochemical (PEC) cytosensors, a combination of the PEC process and the living-cell assay, have emerged as a powerful tool in the analytical and biological science. This mini review provides a brief introduction of this arena and summaries the key steps about the development of PEC cytosensors with representative examples, followed by future prospects based on our own opinions. 相似文献
17.
Li Jun Zheng Dayong Wei Ning Sun Yunfeng Liu Li Yuan Yuan Jiang Qinghua 《Chemistry of Natural Compounds》2022,58(4):650-652
Chemistry of Natural Compounds - A new quassinoid, dehydrobruceantinol B (1), was isolated from the seeds of Brucea javanica, together with two known compounds, bruceantinol (2) and bruceine A (3).... 相似文献
18.
Wei Yuting Wang Qihua Liu Wei 《Annals of the Institute of Statistical Mathematics》2021,73(3):535-553
Annals of the Institute of Statistical Mathematics - In this paper, a model averaging approach is developed for the linear regression models with response missing at random. It is shown that the... 相似文献
19.
Xu Mengtao Li Changyou Sun Yang Yang Tianzhi Zhang Hongzhuang Liu Zhendong Liu Haiyang Li Zhenyuan Zhang Yimin 《Nonlinear dynamics》2021,105(4):3061-3092
Nonlinear Dynamics - Investigation of the dynamic characteristics of linear guideway is essential for enhancing structural performance of machine tools. However, few mechanical models are... 相似文献
20.
Interactions of the vector breathers for the coupled Hirota system with $$4\times 4$$ 4 × 4 Lax pair
Nonlinear Dynamics - In this paper, we investigate the interactions of the vector breathers for the coupled Hirota system with $$4\times 4$$ Lax pair. Firstly, we give the first-order breather... 相似文献