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   13625篇
  免费   1307篇
  国内免费   776篇
化学   8867篇
晶体学   190篇
力学   719篇
综合类   72篇
数学   1671篇
物理学   4189篇
  2023年   174篇
  2022年   305篇
  2021年   351篇
  2020年   459篇
  2019年   436篇
  2018年   424篇
  2017年   406篇
  2016年   556篇
  2015年   441篇
  2014年   637篇
  2013年   837篇
  2012年   833篇
  2011年   909篇
  2010年   646篇
  2009年   578篇
  2008年   677篇
  2007年   614篇
  2006年   527篇
  2005年   435篇
  2004年   338篇
  2003年   347篇
  2002年   303篇
  2001年   226篇
  2000年   236篇
  1999年   211篇
  1998年   189篇
  1997年   191篇
  1996年   198篇
  1995年   204篇
  1994年   213篇
  1993年   171篇
  1992年   137篇
  1991年   152篇
  1990年   159篇
  1989年   126篇
  1988年   111篇
  1987年   116篇
  1986年   103篇
  1985年   113篇
  1984年   138篇
  1983年   89篇
  1982年   107篇
  1981年   84篇
  1980年   81篇
  1979年   117篇
  1978年   103篇
  1977年   107篇
  1976年   115篇
  1975年   97篇
  1973年   85篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Doklady Physics - This work is devoted to analysis and generalization of the kinetic criteria of vitrification using the model of delocalized atoms. The generalized criterion of a...  相似文献   
2.
Russian Physics Journal - The process of radiative decay of a Higgs boson into a fermion-antifermion pair $$ H\Rightarrow \overline{ff}\upgamma . $$ is investigated within the framework of the...  相似文献   
3.
4.
Russian Physics Journal - The paper shows that the values of zero-point energy and vibrations of atoms in a crystal determined by the uncertainty principle, depend on the dynamic response of atoms....  相似文献   
5.
Novel pyrene‐fused unsymmetrical phthalocyanine derivatives 2,3,9,10,16,17‐hexakis(2,6‐dimethylphenoxy)‐22,25‐diaza(2,7‐di‐tert‐butylpyrene)[4,5]phthalocyaninato zinc complex Zn[Pc(Pz‐pyrene)(OC8H9)6] ( 1 ) and 2,3,9,10‐tra(2,6‐dimethylphenoxy)‐15,18,22,25‐traza(2,7‐di‐tert‐butylpyrene)[4,5]phthalocyaninato zinc compound Zn[Pc(Pz‐pyrene)2(OC8H9)4] ( 2 ) were isolated for the first time. These unsymmetrical pyrene‐fused phthalocyanine derivatives have been characterized by a wide range of spectroscopic and electrochemical methods. In particular, the pyrene‐fused phthalocyanine structure was unambiguously revealed on the basis of single crystal X‐ray diffraction analysis of 1 , representing the first structurally characterized phthalocyanine derivative fused with an aromatic moiety larger than benzene.  相似文献   
6.
7.
8.
Three‐dimensional (3D) nanometal films serving as current collectors have attracted much interest recently owing to their promising application in high‐performance supercapacitors. In the process of the electrochemical reaction, the 3D structure can provide a short diffusion path for fast ion transport, and the highly conductive nanometal may serve as a backbone for facile electron transfer. In this work, a novel polypyrrole (PPy) shell@3D‐Ni‐core composite is developed to enhance the electrochemical performance of conventional PPy. With the introduction of a Ni metal core, the as‐prepared material exhibits a high specific capacitance (726 F g?1 at a charge/discharge rate of 1 A g?1), good rate capability (a decay of 33 % in Csp with charge/discharge rates increasing from 1 to 20 A g?1), and high cycle stability (only a small decrease of 4.2 % in Csp after 1000 cycles at a scan rate of 100 mV s?1). Furthermore, an aqueous symmetric supercapacitor device is fabricated by using the as‐prepared composite as electrodes; the device demonstrates a high energy density (≈21.2 Wh kg?1) and superior long‐term cycle ability (only 4.4 % and 18.6 % loss in Csp after 2000 and 5000 cycles, respectively).  相似文献   
9.
The design and exploration of efficient, stable and environmentally compatible organic emitters for an electrochemiluminescence (ECL) sensor is a promising topic. Herein, a novel environmentally-friendly luminophore, ZnBCBTP@MWCNTs, were fabricated via self-assembly of porphyrin molecules (ZnBCBTP) onto multi-walled carbon nanotubes (MWCNTs). The resulting luminophore ZnBCBTP@MWCNTs displayed not only the highly ECL property and but also the good accelerated electron mobility. Then, a label-free ECL biosensor based ZnBCBTP@MWCNTs was constructed for the ultrasensitive detection of uric acid. Excitingly, this proposed ECL biosensor performed a good linear relationship in the range of 0–300 μM with a low detection limit of 1.4 μM, thus offering another reliable and feasible sensing platform for clinical bioanalysis with good selectivity, stability, and repeatability.  相似文献   
10.
Ding  Hao  Wang  Jin-Ting  Lu  Li-Qiao  Pan  Jian-Wen 《Nonlinear dynamics》2021,104(4):3365-3384
Nonlinear Dynamics - Conventional tuned liquid column dampers (TLCDs) are deficient in multidirectionality. In contrast, toroidal TLCDs are designed to extend the application to multidirectional...  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