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   6415篇
  免费   1249篇
  国内免费   937篇
化学   4482篇
晶体学   158篇
力学   408篇
综合类   106篇
数学   752篇
物理学   2695篇
  2024年   3篇
  2023年   110篇
  2022年   172篇
  2021年   238篇
  2020年   319篇
  2019年   352篇
  2018年   273篇
  2017年   324篇
  2016年   349篇
  2015年   392篇
  2014年   450篇
  2013年   607篇
  2012年   697篇
  2011年   655篇
  2010年   518篇
  2009年   519篇
  2008年   512篇
  2007年   417篇
  2006年   336篇
  2005年   292篇
  2004年   227篇
  2003年   159篇
  2002年   138篇
  2001年   108篇
  2000年   80篇
  1999年   75篇
  1998年   32篇
  1997年   42篇
  1996年   46篇
  1995年   46篇
  1994年   20篇
  1993年   23篇
  1992年   14篇
  1991年   14篇
  1990年   11篇
  1989年   10篇
  1988年   1篇
  1987年   2篇
  1986年   2篇
  1985年   5篇
  1984年   2篇
  1983年   2篇
  1982年   3篇
  1980年   2篇
  1936年   2篇
排序方式: 共有8601条查询结果,搜索用时 15 毫秒
1.
International Journal of Theoretical Physics - We investigate the monogamy relations related to the concurrence, the entanglement of formation, convex-roof extended negativity, Tsallis-q...  相似文献   
2.

We study the Bell nonlocality of high dimensional quantum systems based on quantum entanglement. A quantitative relationship between the maximal expectation value B of Bell operators and the quantum entanglement concurrence C is obtained for even dimension pure states, with the upper and lower bounds of B governed by C.

  相似文献   
3.
Journal of Radioanalytical and Nuclear Chemistry - To analyze the effect of scintillator detectors on the fast neutron multiplicity, this paper uses Geant4 and Matlab to simulate and study three...  相似文献   
4.
Liu  Jingze  Fei  Qingguo  Wu  Shaoqing  Tang  Zhenhuan  Zhang  Dahai 《Nonlinear dynamics》2021,106(3):1869-1890
Nonlinear Dynamics - Rolling bearing and squeeze film damper will introduce structural nonlinearity into the dynamic model of aeroengine. Rubbing will occur due to the clearance reduction design of...  相似文献   
5.
Liu  Qingrong  Li  Hanfeng  Zhu  Fei  Zhang  Xianfu 《Nonlinear dynamics》2021,103(3):2659-2669
Nonlinear Dynamics - This paper proposes an output feedback control strategy to achieve the global regulation of a class of large-scale feedforward nonlinear systems with discrete and distributed...  相似文献   
6.
International Journal of Theoretical Physics - Quantifying the quantumness of ensembles is a vital and practical task in quantum information theory. In this paper, we quantify the quantumness of...  相似文献   
7.
Wan  Qiuzhen  Yan  Zidie  Li  Fei  Liu  Jiong  Chen  Simiao 《Nonlinear dynamics》2022,109(3):2085-2101
Nonlinear Dynamics - This paper investigates a Hopfield neural network under the simulation of external electromagnetic radiation and dual bias currents, in which the fluctuation of magnetic flux...  相似文献   
8.
The collisional dynamics of two symmetric droplets with equal intraspecies scattering lengths and particle number density for each component is studied by solving the corresponding extended Gross−Pitaevskii equation in two dimensions by including a logarithmic correction term in the usual contact interaction. We find the merging droplet after collision experiences a quadrupole oscillation in its shape and the oscillation period is found to be independent of the incidental momentum for small droplets. With increasing collision momentum the colliding droplets may separate into two, or even more, and finally into small pieces of droplets. For these dynamical phases we manage to present boundaries determined by the remnant particle number in the central area and the damped oscillation of the quadrupole mode. A stability peak for the existence of droplets emerges at the critical particle numberNc ≃ 48 for the quasi-Gaussian and flat-top shapes of the droplets.  相似文献   
9.
Yi  Lanhua  Hu  You  Fei  Junjie  Li  Juan  Yang  Chunguang  Wang  Xianyou 《Journal of Solid State Electrochemistry》2019,23(6):1739-1748
Journal of Solid State Electrochemistry - Pd/C and Pd-Co/C nanocatalysts are prepared via a simple and environmentally friendly method and are used as anodic catalyst for direct...  相似文献   
10.
The majority of natural product biosynthetic gene clusters in bacteria are silent under standard laboratory growth conditions, making it challenging to uncover any antibiotics that they may encode. Herein, bioactivity assays are combined with high‐throughput elicitor screening (HiTES) to access cryptic, bioactive metabolites. Application of this strategy in Saccharopolyspora cebuensis, with inhibition of Escherichia coli growth as a read‐out, led to the identification of a novel lanthipeptide, cebulantin. Extensive NMR spectroscopic analysis allowed the elucidation of the structure of cebulantin. Subsequent bioactivity assays revealed it to be an antibiotic selective for Gram‐negative bacteria, especially against Vibrio species. This approach, referred to as bioactivity‐HiTES, has the potential to uncover cryptic metabolites with desired biological activities that are hidden in microbial genomes.  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