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   10696篇
  免费   1453篇
  国内免费   1580篇
化学   5653篇
晶体学   101篇
力学   679篇
综合类   65篇
数学   2851篇
物理学   4380篇
  2024年   15篇
  2023年   370篇
  2022年   352篇
  2021年   465篇
  2020年   451篇
  2019年   466篇
  2018年   435篇
  2017年   467篇
  2016年   462篇
  2015年   581篇
  2014年   745篇
  2013年   987篇
  2012年   1007篇
  2011年   1042篇
  2010年   810篇
  2009年   773篇
  2008年   680篇
  2007年   680篇
  2006年   671篇
  2005年   373篇
  2004年   306篇
  2003年   228篇
  2002年   204篇
  2001年   210篇
  2000年   145篇
  1999年   171篇
  1998年   88篇
  1997年   66篇
  1996年   60篇
  1995年   50篇
  1994年   53篇
  1993年   40篇
  1992年   44篇
  1991年   40篇
  1990年   32篇
  1989年   30篇
  1988年   21篇
  1987年   28篇
  1986年   22篇
  1985年   14篇
  1984年   12篇
  1983年   9篇
  1982年   13篇
  1981年   5篇
  1979年   1篇
  1976年   2篇
  1957年   2篇
  1936年   1篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Zhong  Weizhou  Zhang  Zexiong  Chen  Xiaowei  Wei  Qiang  Chen  Gang  Huang  Xicheng 《Acta Mechanica Sinica》2021,37(7):1136-1151
Acta Mechanica Sinica - Multi-scale finite element method is adopted to simulate wood compression behavior under axial and transverse loading. Representative volume elements (RVE) of wood...  相似文献   
2.
Zhu  Min  Li  Jun-ping  Liu  De-zhi 《应用数学学报(英文版)》2021,37(3):617-627
Acta Mathematicae Applicatae Sinica, English Series - So far there have been few results presented on the exponential stability for time-changed stochastic differential equations. The main aim of...  相似文献   
3.
International Journal of Theoretical Physics - In this paper, we investigate Einstein-Podolsky-Rosen steering, Bell non-locality, first-order coherence and concurrence in the spin- $\frac {1}{2}$...  相似文献   
4.
The chiral phase transition and equation of state are studied within a novel self-consistent mean-field approximation of the two-flavor Nambu-Jona-Lasinio model. In this newly developed model, modifications to the chemical μ and chiral chemical \begin{document}$\mu_5$\end{document} potentials are naturally included by introducing vector and axial-vector channels from Fierz-transformed Lagrangian to the standard Lagrangian. In the proper-time scheme, the chiral phase transition is a crossover in the \begin{document}$T-\mu$\end{document} plane. However, when \begin{document}$\mu_5$\end{document} is incorporated, our study demonstrates that a first order phase transition may emerge. Furthermore, the chiral imbalance will soften the equation of state of quark matter. The mass-radius relationship and tidal deformability of quark stars are calculated. The maximum mass and radius decrease as \begin{document}$\mu_5$\end{document} increases. Our study also indicates that the vector and axial-vector channels exhibit an opposite influence on the equation of state.  相似文献   
5.
Song  Zi-Long  Zhu  Yun  Liu  Jing-Rui  Guo  Shu-Ke  Gu  Yu-Cheng  Han  Xinya  Dong  Hong-Qiang  Sun  Qi  Zhang  Wei-Hua  Zhang  Ming-Zhi 《Molecular diversity》2021,25(1):205-221
Molecular Diversity - Based on the strategy of diversity-oriented synthesis and the structures of natural product pimprinine and streptochlorin, two series of novel pimprinine derivatives...  相似文献   
6.
This paper is concerned with the Cauchy problem on the Boltzmann equation without angular cutoff assumption for hard potential in the whole space. When the initial data is a small perturbation of a global Maxwellian, the global existence of solution to this problem is proved in unweighted Sobolev spaces HN(Rx,v6) with N2. But if we want to obtain the optimal temporal decay estimates, we need to add the velocity weight function, in this case the global existence and the optimal temporal decay estimate of the Boltzmann equation are all established. Meanwhile, we further gain a more accurate energy estimate, which can guarantee the validity of the assumption in Chen et al. (0000).  相似文献   
7.

The dependence structure of the life statuses plays an important role in the valuation of life insurance products involving multiple lives. Although the mortality of individuals is well studied in the literature, their dependence remains a challenging field. In this paper, the main objective is to introduce a new approach for analyzing the mortality dependence between two individuals in a couple. It is intended to describe in a dynamic framework the joint mortality of married couples in terms of marginal mortality rates. The proposed framework is general and aims to capture, by adjusting some parametric form, the desired effect such as the “broken-heart syndrome”. To this end, we use a well-suited multiplicative decomposition, which will serve as a building block for the framework to relate the dependence structure and the marginals, and we make the link with existing practice of affine mortality models. Finally, given that the framework is general, we propose some illustrative examples and show how the underlying model captures the main stylized facts of bivariate mortality dynamics.

  相似文献   
8.
9.
10.
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