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   170篇
  免费   2篇
化学   60篇
力学   6篇
数学   32篇
物理学   74篇
  2022年   1篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   6篇
  2016年   2篇
  2015年   3篇
  2014年   4篇
  2013年   4篇
  2012年   7篇
  2011年   8篇
  2010年   3篇
  2009年   6篇
  2008年   6篇
  2007年   3篇
  2006年   4篇
  2005年   5篇
  2004年   3篇
  2003年   1篇
  2002年   7篇
  2001年   4篇
  2000年   10篇
  1999年   8篇
  1998年   5篇
  1997年   2篇
  1996年   12篇
  1995年   3篇
  1994年   10篇
  1993年   6篇
  1992年   5篇
  1989年   3篇
  1988年   1篇
  1987年   3篇
  1986年   1篇
  1985年   3篇
  1984年   3篇
  1982年   4篇
  1981年   4篇
  1980年   4篇
  1979年   2篇
  1973年   1篇
  1969年   1篇
排序方式: 共有172条查询结果,搜索用时 265 毫秒
1.
2.
3.
4.
5.
6.
7.
8.
Titration microcalorimetry is used to study the influences of iodide, bromide, and chloride counterions on the aggregation of vesicle-forming 1-methyl-4-(2-pentylheptyl)pyridinium halide surfactants. Formation of vesicles by these surfactants was characterised using transmission electron microscopy. When the counterion is changed at 303 K through the series iodide, bromide, to chloride, the critical vesicular concentration (cvc) increases and the enthalpy of vesicle formation changes from exo- to endothermic. With increase in temperature to 333 K, vesicle formation becomes strongly exothermic. Increasing the temperature leads to a decrease in enthalpy and entropy of vesicle formation for all three surfactants. However the standard Gibbs energy for vesicle formation is, perhaps surprisingly, largely unaffected by an increase in temperature, as a consequence of a compensating change in both standard entropy and standard enthalpy of vesicle formation. Interestingly, standard isobaric heat capacities of vesicle formation are negative, large in magnitude but not strikingly dependent on the counterion. We conclude that the driving force for vesicle formation can be understood in terms of overlap of the thermally labile hydrophobic hydration shells of the alkyl chains. Copyright 2000 Academic Press.  相似文献   
9.
The effects exhibited by adsorbed conducting polyaniline on the redox process on a molybdenum oxide surface were studied. Thermogravimetric results indicate a 4% polyaniline deposition. Cyclic voltammograms of the adsorbed polymer on MoO3 show that polyaniline exerts remarkable effects on the molybdenum blue oxidation-reduction process, with oxidation and reduction potentials of 0.33 and 0.18 V, respectively. This effect strongly enhances the electrode response, and can be used as an important tool in qualitative and/or quantitative determinations of molybdenum in solution as well as in any substrate. Copyright 1999 Academic Press.  相似文献   
10.
Measuring the metabolome: current analytical technologies   总被引:44,自引:0,他引:44  
Dunn WB  Bailey NJ  Johnson HE 《The Analyst》2005,130(5):606-625
The post-genomics era has brought with it ever increasing demands to observe and characterise variation within biological systems. This variation has been studied at the genomic (gene function), proteomic (protein regulation) and the metabolomic (small molecular weight metabolite) levels. Whilst genomics and proteomics are generally studied using microarrays (genomics) and 2D-gels or mass spectrometry (proteomics), the technique of choice is less obvious in the area of metabolomics. Much work has been published employing mass spectrometry, NMR spectroscopy and vibrational spectroscopic techniques, amongst others, for the study of variations within the metabolome in many animal, plant and microbial systems. This review discusses the advantages and disadvantages of each technique, putting the current status of the field of metabolomics in context, and providing examples of applications for each technique employed.  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