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   58279篇
  免费   853篇
  国内免费   291篇
化学   26947篇
晶体学   864篇
力学   3170篇
综合类   8篇
数学   4656篇
物理学   23778篇
  2022年   421篇
  2021年   453篇
  2020年   447篇
  2019年   425篇
  2018年   571篇
  2017年   496篇
  2016年   899篇
  2015年   636篇
  2014年   993篇
  2013年   2505篇
  2012年   2342篇
  2011年   3021篇
  2010年   2129篇
  2009年   2179篇
  2008年   2755篇
  2007年   2602篇
  2006年   2469篇
  2005年   2189篇
  2004年   1995篇
  2003年   1749篇
  2002年   1566篇
  2001年   2971篇
  2000年   2077篇
  1999年   1485篇
  1998年   1026篇
  1997年   1001篇
  1996年   813篇
  1995年   767篇
  1994年   695篇
  1993年   604篇
  1992年   941篇
  1991年   932篇
  1990年   844篇
  1989年   736篇
  1988年   729篇
  1987年   793篇
  1986年   650篇
  1985年   877篇
  1984年   824篇
  1983年   562篇
  1982年   563篇
  1981年   536篇
  1980年   497篇
  1979年   620篇
  1978年   647篇
  1977年   663篇
  1976年   579篇
  1975年   481篇
  1974年   527篇
  1973年   453篇
排序方式: 共有10000条查询结果,搜索用时 515 毫秒
1.
Kobayashi  M.  Zhang  Y.  Ishikawa  H.  Sun  J.  Oddershede  J.  Juul Jensen  D.  Miura  H. 《Experimental Mechanics》2021,61(5):817-828
Experimental Mechanics - The internal strain distribution developing during plastic deformation is important for understanding the mechanical properties of polycrystalline materials. Such...  相似文献   
2.
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   
3.
Crystallography Reports - The review describes the application of small-angle scattering (SAS) of neutrons and complementary methods to study the structures of biomacromolecules. Here we cover SAS...  相似文献   
4.
Russian Physics Journal - Connection of Pauli’s principle with the nontrivial structure of the fermion supertime is shown. When supersymmetry is localized as supergravitation, fields of...  相似文献   
5.
Chen  C. Y.  Kao  C. L.  Huang  S. T.  Kuo  C. E.  Song  P. L.  Li  W. J.  Hsu  L. T.  Li  H. T. 《Chemistry of Natural Compounds》2022,58(1):107-109
Chemistry of Natural Compounds -  相似文献   
6.
Doklady Physical Chemistry - The rheological behavior of a 1 wt % suspension of highly porous chitosan particles in polydimethylsiloxane in a high electric field has been studied as a function of...  相似文献   
7.
Spin-crossover complexes with multistep transitions attract much attention due to their potential applications as multi-switches and for data storage. A four-step spin crossover is observed in the new iron(II)-based cyanometallic guest-free framework compound Fe(2-ethoxypyrazine)2{Ag(CN)2}2 during the transition from the low-spin to the high-spin state. A reverse process occurs in three steps. Crystallographic studies reveal an associated stepwise evolution of the crystal structures. Multiple transitions in the reported complex originate from distinct FeII sites which exist due to the packing of the ligand with a bulky substituent.  相似文献   
8.
Circularly polarized luminescence (CPL) has attracted attention as a next-generation light signal because of its carrying more information compared with normal and linearly polarized lights as well as its potential wide application in information fields. Recently, much attention has been paid to small organic molecules-based CPL emitters because of easy synthesis, fine structural modification at molecular level, and tunable wide range emission wavelength. This review highlights the development of small organic molecules-based CPL emitters in the past 5 years (2017–2021). The progress suggests that small organic molecules-based CPL emitters provide a simple and efficient way to generate CPL.  相似文献   
9.
Covalent functionalization of 2D materials provides a tailored approach towards tuning of their chemical, optical, and electronic properties making the search for new ways to graft small molecules important. Herein, the reaction with (3,5-bis(trifluoromethyl)phenyl)iodonium salt is revealed as an effective strategy for functionalization of MoTe2 thin films. Upon decomposition of the salt, the generated radicals graft covalently as aryl-(CF3)2 groups at the surface of both metallic (1T’) and semiconducting (2H) polymorphs of MoTe2. Remarkably, the reactivity of the salt is governed by the electronic structure of the given polymorph. While the functionalization of the metallic MoTe2 occurs spontaneously, the semiconducting MoTe2 requires activation by light. The reaction proceeds with the elimination of oxide from the original films yielding the functionalized products that remain protected in ambient conditions, presenting a viable solution to the ageing of MoTe2 in air.  相似文献   
10.
Structural Chemistry - Quantum chemical calculations have been performed at the M06–2X/6–31G(d,p) level of theory to investigate the strength and nature of interactions between the...  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