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   1816篇
  免费   307篇
  国内免费   168篇
化学   1412篇
晶体学   16篇
力学   100篇
综合类   5篇
数学   146篇
物理学   612篇
  2024年   3篇
  2023年   39篇
  2022年   28篇
  2021年   74篇
  2020年   70篇
  2019年   74篇
  2018年   69篇
  2017年   51篇
  2016年   86篇
  2015年   91篇
  2014年   96篇
  2013年   118篇
  2012年   178篇
  2011年   184篇
  2010年   108篇
  2009年   93篇
  2008年   130篇
  2007年   121篇
  2006年   105篇
  2005年   106篇
  2004年   67篇
  2003年   38篇
  2002年   48篇
  2001年   29篇
  2000年   31篇
  1999年   35篇
  1998年   21篇
  1997年   26篇
  1996年   21篇
  1995年   23篇
  1994年   19篇
  1993年   12篇
  1992年   16篇
  1991年   22篇
  1990年   16篇
  1989年   4篇
  1988年   5篇
  1987年   7篇
  1986年   2篇
  1985年   5篇
  1983年   5篇
  1982年   1篇
  1981年   2篇
  1980年   4篇
  1979年   1篇
  1978年   1篇
  1976年   2篇
  1974年   1篇
  1947年   1篇
  1946年   1篇
排序方式: 共有2291条查询结果,搜索用时 15 毫秒
1.
Annals of Global Analysis and Geometry - We study harmonic maps from a 3-manifold with boundary to $$\mathbb {S}^1$$ and prove a special case of Gromov dihedral rigidity of three-dimensional cubes...  相似文献   
2.
Journal of Solid State Electrochemistry - In this work, nanorods like bimetallic Zn/Mn metal–organic-frameworks (MOFs) are proposed as the precursor for preparing MnxOy/porous carbon...  相似文献   
3.
The coordination chemistry of f-block elements (lanthanide and actinide) in molten salts has become a resounding topic in view of its great importance to the research and development (R&D) of molten salt reactors and pyroprocessing. In this Review article, a general overview of the coordination chemistry of f-block elements in molten salts is provided including past achievements and recent advances. Particular emphases are placed on the oxidation state, speciation, and solution structure of f-block metal ions in molten salts, as well as their relationships with the salt composition. Furthermore, this review briefly discusses the spectroscopic and theoretical methods that complement each other in revealing the coordination properties.  相似文献   
4.
5.
The hierarchical assembly of well‐organized submoieties could lead to more complicated superstructures with intriguing properties. We describe herein an unprecedented polyrotaxane polythreading framework containing a two‐fold nested super‐polyrotaxane substructure, which was synthesized through a uranyl‐directed hierarchical polythreading assembly of one‐dimensional polyrotaxane chains and two‐dimensional polyrotaxane networks. This special assembly mode actually affords a new way of supramolecular chemistry instead of covalently linked bulky stoppers to construct stable interlocked rotaxane moieties. An investigation of the synthesis condition shows that sulfate can assume a vital role in mediating the formation of different uranyl species, especially the unique trinuclear uranyl moiety [(UO2)3O(OH)2]2+, involving a notable bent [O=U=O] bond with a bond angle of 172.0(9)°. Detailed analysis of the coordination features, the thermal stability as well as a fluorescence, and electrochemical characterization demonstrate that the uniqueness of this super‐polyrotaxane structure is mainly closely related to the trinuclear uranyl moiety, which is confirmed by quantum chemical calculations.  相似文献   
6.
7.
The requirement for nitric oxide (NO) of lysosomes has motivated the development of a sophisticated fluorescent probe to monitor the distribution of this important biomolecule at the subcellular level in living cells. A near‐infrared (NIR) fluorescent Si‐rhodamine (SiRB)‐NO probe was designed based on the NO‐induced ring‐opening process of Si‐rhodamine. The probe exhibits fast chromogenic and fluorogenic responses, and high sensitivity and selectivity toward trace amounts of NO. Significantly, the spirolactam in Si‐rhodamine exhibits very good tolerance to H+, which in turn brings extremely low background fluorescence not only in the physiological environment but also under acidic conditions. The stability of the highly fluorescent product in acidic solution provides persistent fluorescence emission for long‐term imaging experiments. To achieve targeted imaging with improved spatial resolution and sensitivity, an efficient lysosome‐targeting moiety was conjugated to a SiRB‐NO probe, affording a tailored lysosome‐targeting NIR fluorescent Lyso‐SiRB‐NO probe. Inheriting the key advantages of its parent SiRB‐NO probe, Lyso‐SiRB‐NO is a functional probe that is suited for monitoring lysosomal NO with excellent lysosome compatibility. Imaging experiments demonstrated the monitoring of both exogenous and endogenous NO in real time by using the Lyso‐SiRB‐NO probe.  相似文献   
8.
9.
10.
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