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   1362篇
  免费   228篇
  国内免费   151篇
化学   911篇
晶体学   27篇
力学   339篇
综合类   7篇
数学   127篇
物理学   330篇
  2024年   3篇
  2023年   17篇
  2022年   48篇
  2021年   54篇
  2020年   76篇
  2019年   58篇
  2018年   41篇
  2017年   70篇
  2016年   114篇
  2015年   84篇
  2014年   78篇
  2013年   109篇
  2012年   89篇
  2011年   110篇
  2010年   74篇
  2009年   77篇
  2008年   74篇
  2007年   61篇
  2006年   69篇
  2005年   37篇
  2004年   41篇
  2003年   56篇
  2002年   40篇
  2001年   34篇
  2000年   24篇
  1999年   42篇
  1998年   29篇
  1997年   16篇
  1996年   13篇
  1995年   17篇
  1994年   9篇
  1993年   14篇
  1992年   9篇
  1991年   6篇
  1990年   4篇
  1989年   8篇
  1988年   8篇
  1987年   2篇
  1986年   4篇
  1985年   8篇
  1984年   4篇
  1983年   1篇
  1981年   2篇
  1978年   1篇
  1971年   1篇
  1957年   4篇
  1936年   1篇
排序方式: 共有1741条查询结果,搜索用时 15 毫秒
31.
(C6H5)3MX2 (M = As, Sb; X = OCOCF3 and M = Sb, Bi; X = SO3F, SO3CF3) compounds prepared by the interaction of triphenylmetal(V) substrates with (CF3CO)2O, (CF3SO2)2O and (FSO2)2O have been characterized by molecular weight determination, elemental and spectroscopic (IR, 1H and 19F NMR, mass) analyses.  相似文献   
32.
We present a computational protocol which uses the known three-dimensional structure of a target enzyme to identify possible ligands from databases of compounds with low molecular weight. This is accomplished by first mapping the essential interactions in the binding site with the program GRID. The resulting regions of favorable interaction between target and ligand are translated into a database query, and with UNITY a flexible 3D database search is performed. The feasibility of this approach is calibrated with thrombin as the target. Our results show that the resulting hit lists are enriched with thrombin inhibitors compared to the total database.  相似文献   
33.
新型有序结构分子聚集体的构筑   总被引:4,自引:0,他引:4       下载免费PDF全文
本文概述了近年来我们在新型有序结构分子聚集体构筑方面取得的一些主要成绩,并展望了今后进一步的研究和发展方向。  相似文献   
34.
The template function of cationic particle monolayers bearing quaternary ammonium groups on their surfaces towards anionic colloids was investigated in this paper. Monodispersed cationic polymer particles having quaternary ammonium groups were self-organized on octadecylated glass plates through hydrophobic interaction. The morphology of the resulting particle monolayers was changed by tuning hydrophilic–hydrophobic balance of particles to fabricate aggregated type and dispersed type of particle monolayers. Gold and silver colloids were selectively deposited onto the particle monolayers through electrostatic interaction. The deposited gold and silver colloids on particle monolayers showed plasmon absorbance. Fluorescent silica colloids were also selectively deposited on particle monolayers to permit fluorescence labeling of the particle monolayers. Cationic particle monolayers fabricated on hydrophobic solid octadecylated were found to effectively work as templates for the deposition of above mentioned inorganic colloids.  相似文献   
35.
《Mendeleev Communications》2021,31(5):726-727
Low-temperature XRD measurements were performed to confirm the phase composition and structural parameters of the electrochemically deposited Cu2ZnSnSe4 thin films on flexible metal substrates.  相似文献   
36.
《Electroanalysis》2018,30(2):345-352
We reported here three simple, low cost and easy to accomplish strategies for the fabrication of microelectrodes and other conductive patterns using ordinary office laser‐printers. In this work, toner patterns were directly printed onto the flexible substrate, acting as a mask to create the intended conductive design. To highlight the versatility of such technology, toner‐printed patterns were employed in two diverse ways: one in which the patterned toner had the exact design of the electrode and other employing a reverse toner‐printed pattern. The first one was used for the adaptation of the well‐known printed circuit board (PCB) fabrication technique, but using direct toner printing (DTP) in an already conductive flexible substrate. The second was employed for the two remaining strategies: one based on the deposition of conductive film, followed by lift‐off process; and another based on drop‐casting of a conductive ink into the formed toner cavities, followed by thermal cure. As proof‐of‐concept, all three DTP strategies were used for the fabrication of miniaturized gold electrodes in polyimide substrate, and electrochemical performance of each obtained electrode was evaluated by cyclic voltammetry. Insights about DTP technology, alignment issues, advantages, limitations and resolution of each presented approach were provided. Finally, direct toner printing showed to be a simple, affordable and quite promising technology for the fabrication of low cost point‐of‐care electrochemical devices using flexible platforms.  相似文献   
37.
Quadruply BN-fused tetrathia[8]circulenes were synthesized through four-fold electrophilic borylation. The single-crystal X-ray diffraction analysis revealed that the BN-fused tetrathia[8]circulene with peripheral phenyl groups exhibits crystal polymorphism, in which the circulene core adopts both planar and saddle conformations in the solid state. The experimental and theoretical studies revealed that the weaker aromaticity of azaborine compared with benzene renders the flexibility of the BN-fused tetrathia[8]circulenes.  相似文献   
38.
Room temperature and low temperature (120 °C) laser-assisted glass frit bonding of soda-lime glass substrates are accomplished in this work. The locally laser melted bonding showed hermeticity with helium leak rate of <5×10−8 atm cm3 s−1, maintaining its leak rate even after standard climatic cycle tests. Small size devices were bonded at room temperature while larger areas were sealed at the process temperature of 120 °C. The sealing parameters were optimized through response surface methodology that makes the process capable for further development regardless of device size.  相似文献   
39.
40.
Owing to their remarkable properties, single-walled carbon nanotube thin-film transistors (SWCNT-TFTs) are expected to be used in various flexible electronics applications. To fabricate SWCNT channel layers for TFTs, solution-based film formation on a self-assembled monolayer (SAM) covered with amino groups is commonly used. However, this method uses highly oxidized surfaces, which is not suitable for flexible polymeric substrates. In this work, a solution-based SWCNT film fabrication using methoxycarbonyl polyallylamine (Moc-PAA) is reported. The NH2-terminated surface of the cross-linked Moc-PAA layer enables the formation of highly dense and uniform SWCNT networks on both rigid and flexible substrates. TFTs that use the fabricated SWCNT thin film exhibited excellent performance with small variations. The presented simple method to access SWCNT thin film accelerates the realization of flexible nanoelectronics.  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