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   1361496篇
  免费   30474篇
  国内免费   8524篇
化学   682645篇
晶体学   20635篇
力学   75448篇
综合类   166篇
数学   243566篇
物理学   378034篇
  2021年   13574篇
  2020年   16018篇
  2019年   16110篇
  2018年   14067篇
  2016年   28505篇
  2015年   21084篇
  2014年   30599篇
  2013年   74659篇
  2012年   39378篇
  2011年   37644篇
  2010年   38603篇
  2009年   40869篇
  2008年   36575篇
  2007年   32676篇
  2006年   36903篇
  2005年   30692篇
  2004年   31042篇
  2003年   29009篇
  2002年   29713篇
  2001年   28853篇
  2000年   25001篇
  1999年   22588篇
  1998年   21068篇
  1997年   21050篇
  1996年   21172篇
  1995年   19234篇
  1994年   18684篇
  1993年   18233篇
  1992年   18200篇
  1991年   18438篇
  1990年   17637篇
  1989年   17677篇
  1988年   17252篇
  1987年   17245篇
  1986年   16217篇
  1985年   22632篇
  1984年   23856篇
  1983年   20009篇
  1982年   21698篇
  1981年   20891篇
  1980年   20272篇
  1979年   20434篇
  1978年   21737篇
  1977年   21342篇
  1976年   21075篇
  1975年   19730篇
  1974年   19409篇
  1973年   19866篇
  1972年   14365篇
  1967年   12553篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
Nonlinear Dynamics - In this paper, we analyze the effect which the choice of a friction model has on tippe top inversion in the case where the resulting action of all dissipative forces is...  相似文献   
132.
Fomenko  T. N. 《Mathematical Notes》2021,110(3-4):583-591
Mathematical Notes - The notion of a $$\lambda$$ -generalized-search multivalued functional on an $$f$$ -quasimetric space is introduced. An existence theorem for zeros of such functionals is...  相似文献   
133.
Theoretical and Mathematical Physics - We present a one-line closed-form expression for the three-parameter breather of the nonlinear Schrödinger equation. This provides an analytic proof of...  相似文献   
134.
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   
135.
Ukrainian Mathematical Journal - We establish new criteria of compatibility for a linear system of equations (equivalent to the Kronecker–Capelli theorem) or inequalities (equivalent to the...  相似文献   
136.
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   
137.
Journal of Fourier Analysis and Applications - We develop a theory of Sobolev orthogonal polynomials on the Sierpiński gasket ( $$SG$$ ), which is a fractal set that can be viewed as a limit...  相似文献   
138.
A temperature control unit was implemented to vary the temperature of samples studied on a commercial Mobile Universal Surface Explorer nuclear magnetic resonance (MOUSE-NMR) apparatus. The device was miniaturized to fit the maximum MOUSE sampling depth (25 mm). It was constituted by a sample holder sandwiched between two heat exchangers placed below and above the sample. Air was chosen as the fluid to control the temperature at the bottom of the sample, at the interface between the NMR probe and the sample holder, in order to gain space. The upper surface of the sample was regulated by the circulation of water inside a second heat exchanger placed above the sample holder. The feasibility of using such a device was demonstrated first on pure water and then on several samples of bread dough with different water contents. For this, T1 relaxation times were measured at various temperatures and depths and were then compared with those acquired with a conventional compact closed-magnet spectrometer. Discussion of results was based on biochemical transformations in bread dough (starch gelatinization and gluten heat denaturation). It was demonstrated that, within a certain water level range, and because of the low magnetic field strength of the MOUSE, a linear relationship could be established between T1 relaxation times and the local temperature in the dough sample.  相似文献   
139.
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   
140.
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   
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