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   438篇
  免费   3篇
  国内免费   1篇
化学   358篇
晶体学   7篇
力学   7篇
数学   12篇
物理学   58篇
  2022年   2篇
  2021年   3篇
  2020年   3篇
  2019年   8篇
  2018年   6篇
  2017年   1篇
  2016年   4篇
  2015年   3篇
  2014年   9篇
  2013年   16篇
  2012年   23篇
  2011年   36篇
  2010年   16篇
  2009年   20篇
  2008年   27篇
  2007年   35篇
  2006年   35篇
  2005年   22篇
  2004年   24篇
  2003年   24篇
  2002年   19篇
  2001年   3篇
  2000年   2篇
  1999年   9篇
  1998年   5篇
  1997年   4篇
  1996年   7篇
  1995年   4篇
  1994年   6篇
  1993年   5篇
  1992年   4篇
  1991年   6篇
  1990年   5篇
  1989年   8篇
  1988年   6篇
  1987年   1篇
  1986年   4篇
  1985年   6篇
  1984年   6篇
  1983年   2篇
  1982年   2篇
  1981年   3篇
  1980年   2篇
  1979年   1篇
  1977年   1篇
  1975年   2篇
  1971年   1篇
  1966年   1篇
排序方式: 共有442条查询结果,搜索用时 31 毫秒
111.
Applied Biochemistry and Biotechnology - Among forty strains of marine cyanobacteria isolated in our laboratory, five strains had 1–3 different plasmids. The unicellular marine...  相似文献   
112.
This communication describes a new molecular recognition chip using a semi-wet microenvironment provided by a self-assembled hydrogel. On the basis of the evidence that the molecular recognition capability of artificial chemosensors are practically retained even in the hydrogel compared to those in aqueous solution, we miniaturized the functionalized hydrogel to produce an unprecedented molecular recognition chip. We believe that the present noncovalent immobilization method is generally applicable to many chemosensors, which leads to a unique semi-wet sensor chip suitable to convenient and high-throughput assay to plural analytes.  相似文献   
113.
Bi-galactose-branched cyclodextrins (Bi-Gal-CDs)(1–6) having different spacer arm lengths between two terminal galactoses were foundto have the optimum length for association with PNA lectin. Also, the inclusioninteraction of the drug depended on the length of the spacer arms. The dual association of thesecompounds was quantitatively evaluated by SPR and compared to the other oligosaccharide-branchedCDs (Scheme 1). The number and the length of the spacer arm are important for theassociation both with the lectin and drug for the purpose of targeting drug-delivery systems.The association constants K of bi-Gal-CD (2) with rat liver cells showed a 60 timeshigher association than with PNA. Direct evidence of the association between PNA andbi-Gal-CD (2) was characterized by AFM observations. The results obtained strongly suggested a method to find a new design for the targeting drug carrier. In order toincrease the association with the cell, a sufficient spacer arm length is necessary for the effectivedual recognition of the oligosaccharide-CDs. In order to increase the inclusion of thedrug, the CD structure of a multi-saccharide branch is necessary.  相似文献   
114.
Optical Review - The correlation between electrical properties and surface plasmon resonance (SPR) wavelength was discussed using ITO grating coupler. ITO films were prepared on SiO $$_{2}$$ /Si...  相似文献   
115.
Abstract

Photoluminescence of TCNQ-amino adducts was studied to evaluate solid state samples of photoluminescence quantum yields. High PL quantum yields suggests that TCNQ-amino adducts should be an excellent organic light emitter. Electroluminescence of TCNQ-amino adducts was demonstrated for the first time.  相似文献   
116.
117.
The Ramanujan Journal - We give a new method to prove in a uniform and easy way various transformation formulas for Gauss hypergeometric functions. The key is Jacobi’s canonical form of the...  相似文献   
118.
119.
We propose a one-dimensional array of superconducting quantum interference devices (SQUIDs) composed of three asymmetrically positioned Josephson junctions to realize a discrete double sine-Gordon (DSG) model. Two fluxons in this SQUID array attract each other and form bound states with internal oscillation modes. We conduct numerical simulations of a discrete DSG equation, and show that the period of the internal oscillation of a moving fluxon pair exhibits relativistic time dilation except near the speed of light. We also show that driving with a pure alternating current causes progressive motion of the bound fluxon pair even in the presence of dissipation.  相似文献   
120.
Chemical investigations of the MeOH-CH2Cl2 extract of Pseudopterogorgia elisabethae specimens collected in the islands of San Andrés and Providencia, Colombian Caribbean, yielded four new diterpenes (1, 3, 5, 7) along with seco-pseudopterosin J (8), and amphilectosins A (9) and B (10). The structures of the new compounds were established through spectral studies as an elisabethatriene analog named elisabethatrienol (1), 10-acetoxy-9-hydroxy- and 9-acetoxy-10-hydroxy-amphilecta-8,10,12,14-tetraenes (isolated as an interconverting mixture) (3), amphilecta-8(13),11,14-triene-9,10-dione (5), and a seco-pseudopterosin 7-O-α-l-fucopyranoside named seco-pseudopterosin K (7). Elisabethatrienol can be regarded as a biosynthetic intermediate leading to erogorgiaene.  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