全文获取类型
收费全文 | 49281篇 |
免费 | 8087篇 |
国内免费 | 6533篇 |
专业分类
化学 | 36084篇 |
晶体学 | 705篇 |
力学 | 2726篇 |
综合类 | 526篇 |
数学 | 5573篇 |
物理学 | 18287篇 |
出版年
2024年 | 165篇 |
2023年 | 953篇 |
2022年 | 1678篇 |
2021年 | 1728篇 |
2020年 | 1950篇 |
2019年 | 1963篇 |
2018年 | 1648篇 |
2017年 | 1662篇 |
2016年 | 2300篇 |
2015年 | 2307篇 |
2014年 | 2882篇 |
2013年 | 3633篇 |
2012年 | 4408篇 |
2011年 | 4462篇 |
2010年 | 3258篇 |
2009年 | 3124篇 |
2008年 | 3380篇 |
2007年 | 3121篇 |
2006年 | 2932篇 |
2005年 | 2374篇 |
2004年 | 1806篇 |
2003年 | 1471篇 |
2002年 | 1335篇 |
2001年 | 1143篇 |
2000年 | 1042篇 |
1999年 | 1055篇 |
1998年 | 822篇 |
1997年 | 723篇 |
1996年 | 689篇 |
1995年 | 635篇 |
1994年 | 573篇 |
1993年 | 487篇 |
1992年 | 407篇 |
1991年 | 357篇 |
1990年 | 344篇 |
1989年 | 242篇 |
1988年 | 183篇 |
1987年 | 135篇 |
1986年 | 158篇 |
1985年 | 113篇 |
1984年 | 54篇 |
1983年 | 57篇 |
1982年 | 56篇 |
1981年 | 27篇 |
1980年 | 15篇 |
1979年 | 14篇 |
1978年 | 3篇 |
1971年 | 4篇 |
1957年 | 8篇 |
1936年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 406 毫秒
1.
2.
Lin Yu Wu Yeyu Tan Xuecai Wu Jiawen Huang Kejing Mi Yan Ou Panpan Wei Fucun 《Journal of Solid State Electrochemistry》2022,26(4):959-971
Journal of Solid State Electrochemistry - An ultrasensitive “signal-off–on” electrochemiluminescence (ECL) biosensor is constructed based on f1-TiO2/g-C3N4/PDA for thrombin... 相似文献
3.
Potential Analysis - We establish some exact asymptotic results for a matching problem with respect to a family of beta distributions. Let X1,…,Xn be independent random variables with common... 相似文献
4.
Gürbüzbalaban Mert Ruszczyński Andrzej Zhu Landi 《Journal of Optimization Theory and Applications》2022,194(3):1014-1041
Journal of Optimization Theory and Applications - We consider a distributionally robust formulation of stochastic optimization problems arising in statistical learning, where robustness is with... 相似文献
5.
Hua Saixiang Zhu Huichao Wang Xiao Wu Mingyuan Wu Qingyun Liu Jiuyi Yang Jianjun Zhang Jianan 《Cellulose (London, England)》2022,29(13):7465-7475
Cellulose - Ultraviolet (UV) protective cotton fabric is a convenient and reliable way to protect human body from sunlight. Herein, a polymerizable UV-absorber,... 相似文献
6.
7.
This study is to numerically test the interfacial instability of ferrofluid flow under the presence of a vacuum magnetic field. The ferrofluid parabolized stability equations(PSEs) are derived from the ferrofluid stability equations and the Rosensweig equations, and the characteristic values of the ferrofluid PSEs are given to describe the ellipticity of ferrofluid flow. Three numerical models representing specific cases considering with/without a vacuum magnetic field or viscosity are created to mathematically examine the interfacial instability by the computation of characteristic values. Numerical investigation shows strong dependence of the basic characteristic of ferrofluid Rayleigh-Taylor instability(RTI) on viscosity of ferrofluid and independence of the vacuum magnetic field.For the shock wave striking helium bubble, the magnetic field is not able to trigger the symmetry breaking of bubble but change the speed of the bubble movement. In the process of droplet formation from a submerged orifice, the collision between the droplet and the liquid surface causes symmetry breaking. Both the viscosity and the magnetic field exacerbate symmetry breaking. The computational results agree with the published experimental results. 相似文献
8.
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
9.
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
10.
Nonlinear Dynamics - This paper investigates the guaranteed cost positive consensus for linear multi-agent systems (MASs) with multiple time-varying delays and switching topologies. First,... 相似文献