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   67299篇
  免费   10029篇
  国内免费   6548篇
化学   45189篇
晶体学   638篇
力学   4540篇
综合类   515篇
数学   8410篇
物理学   24584篇
  2024年   59篇
  2023年   1355篇
  2022年   1351篇
  2021年   1979篇
  2020年   2491篇
  2019年   2383篇
  2018年   2127篇
  2017年   1880篇
  2016年   2882篇
  2015年   2947篇
  2014年   3507篇
  2013年   4702篇
  2012年   5796篇
  2011年   6014篇
  2010年   4079篇
  2009年   4018篇
  2008年   4191篇
  2007年   3787篇
  2006年   3567篇
  2005年   3092篇
  2004年   2473篇
  2003年   1868篇
  2002年   1574篇
  2001年   1457篇
  2000年   1328篇
  1999年   1481篇
  1998年   1278篇
  1997年   1117篇
  1996年   1170篇
  1995年   1060篇
  1994年   1000篇
  1993年   859篇
  1992年   757篇
  1991年   661篇
  1990年   549篇
  1989年   481篇
  1988年   363篇
  1987年   346篇
  1986年   295篇
  1985年   300篇
  1984年   201篇
  1983年   174篇
  1982年   145篇
  1981年   112篇
  1980年   82篇
  1978年   56篇
  1977年   52篇
  1976年   50篇
  1975年   57篇
  1973年   57篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Journal of Theoretical Probability - This work aims to extend the existing results on the Hausdorff dimension of the classical thick point sets to a more general class of exceptional sets of a...  相似文献   
22.
Huang  Renpei  Chen  Li  Yuan  Xiaoru 《显形杂志》2021,24(2):317-330
Journal of Visualization - Forecast calibration methods based on historical similar atmospheric state are effective means weather forecast accuracy. Conventional approaches search similar forecasts...  相似文献   
23.
Niu  Mu-Qing  Chen  Li-Qun 《Nonlinear dynamics》2021,103(3):2227-2240
Nonlinear Dynamics - Nonlinear vibration isolation provides with an effective way for vibration reduction with broad band and high efficiency. This investigation focuses on the dynamic effects of a...  相似文献   
24.
International Journal of Theoretical Physics - In this work, we give an analytical derivation of the reduced density matrix between two qubits in a cavity field, which is described by the quantum...  相似文献   
25.
We report theoretical studies of electron impact triple differential cross sections of two bio-molecules,pyrimidine and tetrahydrofurfuryl alcohol,in the coplanar asymmetric kinematic conditions with the impact energy of 250 eV and ejected electron energy of 20 eV at three scattering angles of-5°,-10°,and-15°.Present multi-center distorted-wave method well describes the experimental data,which was obtained by performing(e,2e)experiment.The calculations show that the secondary electron produced by the primary impact electron is strongly influenced by the molecular ionic multi-center potential,which must be considered when the low energy electron interacts with DNA analogues.  相似文献   
26.
Chen  Liang  Zhu  Junyuan  Zhao  Xinyuan 《中国科学 数学(英文版)》2022,65(11):2397-2422
Science China Mathematics - In this paper, we accomplish the unified convergence analysis of a second-order method of multipliers (i.e., a second-order augmented Lagrangian method) for solving the...  相似文献   
27.
Chen  R. J.  Chen  W.  Kong  F. L. 《Analysis Mathematica》2022,48(1):19-28

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   
28.
Ferroptosis triggered by hemin is regarded as a primary factor accounting for neuronal death secondary to intracerebral hemorrhage. Thus, compounds with inhibitory effect on hemin-induced ferroptosis might be potential medicines to prevent neuronal death caused by intracerebral hemorrhage. Herein, we investigate whether maltol could alleviate hemin-induced SH-SY5Y cell ferroptosis and its potential mechanisms. It is found that maltol effectively prevents hemin-induced SH-SY5Y cell ferroptosis via three pathways. The first one is inhibiting intracellular iron increase via preventing upregulation of transferrin receptor, the second one is alleviating lipid peroxidation via attenuating H2O2 generation by NOX4 and promoting H2O2 clearance by catalase, and the third one is to reduce peroxidized lipids via maintaining GPX4/GSH pathway. Therefore, maltol is a novel agent preventing hemin-induced SH-SY5Y cell ferroptosis.  相似文献   
29.
Methodology and Computing in Applied Probability - This paper is devoted to the study of an optimal investment and risk control problem for an insurer. The risky asset process and the insurance...  相似文献   
30.
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   
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