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   795339篇
  免费   23832篇
  国内免费   11913篇
化学   415580篇
晶体学   11041篇
力学   42622篇
综合类   554篇
数学   110146篇
物理学   251141篇
  2022年   7651篇
  2021年   9291篇
  2020年   10299篇
  2019年   10976篇
  2018年   16755篇
  2017年   16930篇
  2016年   20106篇
  2015年   12491篇
  2014年   17888篇
  2013年   36402篇
  2012年   33715篇
  2011年   43032篇
  2010年   29851篇
  2009年   29546篇
  2008年   37207篇
  2007年   38440篇
  2006年   28521篇
  2005年   28468篇
  2004年   24160篇
  2003年   21807篇
  2002年   20258篇
  2001年   20296篇
  2000年   16103篇
  1999年   13023篇
  1998年   11182篇
  1997年   10859篇
  1996年   10647篇
  1995年   9346篇
  1994年   9211篇
  1993年   8615篇
  1992年   9088篇
  1991年   9476篇
  1990年   8797篇
  1989年   8486篇
  1988年   8218篇
  1987年   7939篇
  1986年   7622篇
  1985年   9784篇
  1984年   10027篇
  1983年   8328篇
  1982年   8743篇
  1981年   8140篇
  1980年   7819篇
  1979年   8226篇
  1978年   8504篇
  1977年   8298篇
  1976年   8300篇
  1975年   7959篇
  1974年   7744篇
  1973年   8102篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Journal of Applied Mechanics and Technical Physics - Turbulent mixing at interfaces of three-layer gas systems after shock-wave passage has been studied. The influence of the initial roughness of...  相似文献   
102.
Radiophysics and Quantum Electronics - We find self-consistent stationary distributions of the electric field and plasma density in the process of ionization self-channeling of quasielectrostatic...  相似文献   
103.
Melnikov  A.  Aksentyev  A.  Senichev  Y. 《Physics of Atomic Nuclei》2021,84(11):1871-1873
Physics of Atomic Nuclei - We have investigated the robustness of the spin-navigator based method for manipulating the beam polarization to bend magnet installation errors. Toward that end,...  相似文献   
104.
Acridone as a new kind of visible light photocatalyst has been developed to catalyze metal free atom transfer radical polymerization (ATRP). The photocatalyst possess low excited state potential as can undergo an oxidative quenching pathway to initiate ATRP of vinyl monomers. Kinetic study and light on/off reaction demonstrate the “living”/controlled nature of the polymerization by light. Block copolymers can be achieved by using PMMA as macroinitiator to reinitiate polymerization of other vinyl monomers, which shows highly preserved Br chain-end functionality in the synthesized polymers. Moreover, the polymerization can be conducted under air atmosphere as most photocatalysts need anaerobic condition, which may give inspiration of further application of this kind of photocatalyst.  相似文献   
105.
Crystallography Reports - The orientation of grains and the special boundaries formed by them in multicrystalline silicon has been studied by electron backscattered diffraction. It is found that...  相似文献   
106.
Crystallography Reports - Some questions related to the establishment, development, and prospects of physical studies using inelastic thermal-neutron scattering are briefly reviewed. The directions...  相似文献   
107.
Theoretical and Mathematical Physics - The fractional derivative method is used to take wave dispersion into account in the wave equation when describing the propagation of gravitational soliton...  相似文献   
108.
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   
109.
Crystallography Reports - Methods of coherent X-ray diffraction imaging of the spatial structure of noncrystalline objects and nanocrystals (nanostructures) are considered. Particular attention is...  相似文献   
110.
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