首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   79392篇
  免费   16715篇
  国内免费   7684篇
化学   72271篇
晶体学   989篇
力学   3103篇
综合类   548篇
数学   7277篇
物理学   19603篇
  2024年   105篇
  2023年   917篇
  2022年   1423篇
  2021年   1739篇
  2020年   2980篇
  2019年   4166篇
  2018年   2502篇
  2017年   2208篇
  2016年   5297篇
  2015年   5461篇
  2014年   5881篇
  2013年   7191篇
  2012年   6941篇
  2011年   6315篇
  2010年   5808篇
  2009年   5678篇
  2008年   5395篇
  2007年   4626篇
  2006年   4127篇
  2005年   3759篇
  2004年   3037篇
  2003年   2683篇
  2002年   3255篇
  2001年   2454篇
  2000年   2274篇
  1999年   1409篇
  1998年   844篇
  1997年   744篇
  1996年   689篇
  1995年   636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   157篇
  1985年   113篇
  1984年   53篇
  1983年   57篇
  1982年   56篇
  1981年   27篇
  1980年   14篇
  1979年   12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 46 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.
Zhu  Jie-Xiang 《Potential Analysis》2021,55(1):167-188
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.
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.
Li  Mingjun  Zhu  Li 《应用数学和力学(英文版)》2021,42(8):1171-1182
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.
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.
Cao  Xiangyang  Zhang  Chenghui  Zhao  Daduan  Li  Yan 《Nonlinear dynamics》2022,107(4):3557-3572
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   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号