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   1495060篇
  免费   32074篇
  国内免费   8171篇
化学   647196篇
晶体学   20091篇
力学   73963篇
综合类   102篇
数学   238452篇
物理学   360557篇
无线电   194944篇
  2021年   14701篇
  2020年   17327篇
  2019年   17476篇
  2016年   29276篇
  2015年   21639篇
  2014年   32665篇
  2013年   78447篇
  2012年   38198篇
  2011年   33422篇
  2010年   38557篇
  2009年   43824篇
  2008年   37432篇
  2007年   33991篇
  2006年   41804篇
  2005年   33531篇
  2004年   35341篇
  2003年   33620篇
  2002年   34889篇
  2001年   34159篇
  2000年   30680篇
  1999年   28548篇
  1998年   27195篇
  1997年   27128篇
  1996年   26760篇
  1995年   24555篇
  1994年   24047篇
  1993年   23367篇
  1992年   23238篇
  1991年   23375篇
  1990年   22161篇
  1989年   21824篇
  1988年   21027篇
  1987年   19807篇
  1986年   18575篇
  1985年   25144篇
  1984年   26274篇
  1983年   22228篇
  1982年   23626篇
  1981年   22797篇
  1980年   22073篇
  1979年   21994篇
  1978年   23214篇
  1977年   22837篇
  1976年   22399篇
  1975年   21055篇
  1974年   20659篇
  1973年   21123篇
  1972年   15336篇
  1968年   13129篇
  1967年   13203篇
排序方式: 共有10000条查询结果,搜索用时 62 毫秒
191.
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   
192.
Kirovskaya  I. A.  Filatova  T. N.  Nor  P. E. 《Semiconductors》2021,55(2):228-233
Semiconductors - According to developed methods, in the fields of the mutual solubility of initial binary compounds (InP, InSb, and CdS), solid solutions of the InP–CdS and InSb–CdS...  相似文献   
193.
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   
194.
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   
195.
Physics of the Solid State - The external factors which influence the ferromagnetic resonance (FMR) line width in bilayer (ferromagnet/antiferromagnet) exchange-biased systems are studied. The...  相似文献   
196.
Antimony triselenide (Sb2Se3) nanoflake-based nitrogen dioxide (NO2) sensors exhibit a progressive bifunctional gas-sensing performance, with a rapid alarm for hazardous highly concentrated gases, and an advanced memory-type function for low-concentration (<1 ppm) monitoring repeated under potentially fatal exposure. Rectangular and cuboid shaped Sb2Se3 nanoflakes, comprising van der Waals planes with large surface areas and covalent bond planes with small areas, can rapidly detect a wide range of NO2 gas concentrations from 0.1 to 100 ppm. These Sb2Se3 nanoflakes are found to be suitable for physisorption-based gas sensing owing to their anisotropic quasi-2D crystal structure with extremely enlarged van der Waals planes, where they are humidity-insensitive and consequently exhibit an extremely stable baseline current. The Sb2Se3 nanoflake sensor exhibits a room-temperature/low-voltage operation, which is noticeable owing to its low energy consumption and rapid response even under a NO2 gas flow of only 1 ppm. As a result, the Sb2Se3 nanoflake sensor is suitable for the development of a rapid alarm system. Furthermore, the persistent gas-sensing conductivity of the sensor with a slow decaying current can enable the development of a progressive memory-type sensor that retains the previous signal under irregular gas injection at low concentrations.  相似文献   
197.
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   
198.
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   
199.
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   
200.
Crystallography Reports - The specific features of the formation of crystallites in gallium arsenide crystals grown by the Czochralski method have been investigated. The crystallites are found to...  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