全文获取类型
收费全文 | 508篇 |
免费 | 60篇 |
国内免费 | 75篇 |
专业分类
化学 | 529篇 |
力学 | 8篇 |
综合类 | 5篇 |
数学 | 20篇 |
物理学 | 81篇 |
出版年
2022年 | 1篇 |
2019年 | 2篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2014年 | 30篇 |
2013年 | 47篇 |
2012年 | 43篇 |
2011年 | 7篇 |
2010年 | 1篇 |
2009年 | 3篇 |
2008年 | 20篇 |
2007年 | 19篇 |
2006年 | 18篇 |
2005年 | 18篇 |
2004年 | 28篇 |
2003年 | 38篇 |
2002年 | 90篇 |
2001年 | 194篇 |
2000年 | 34篇 |
1999年 | 24篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 1篇 |
1995年 | 3篇 |
排序方式: 共有643条查询结果,搜索用时 46 毫秒
111.
Jian Liang YE Xing Wang ZHOU Zhong CHEN* Zhi Wei CHEN Pei Qiang HUANG* Department of Chemistry Department of Biology Xiamen University Xiamen 《中国化学快报》2001,(11)
K3[VO(O2)2(C2O4)]2H2O, (abbr. BpV (ox)) pertains to peroxovanadium (abbr. pV) complexes, which have been attracted considerable attention nowadays, since they are inhibitors of tyrosine phosphatase and may be developed into a new kind of drugs for the treatment of diabetes1. According to the evidence on water-biperoxovanadium, the molecular mechanism of insulin-like effects of pV involves in irreversibly oxidizing the catalytic cysteine at the active site of the target enzyme2,3. However… 相似文献
112.
Recently, the studies on the interaction of DNA with small molecules have been attracting much interest1-6. These researches not only gave the important information about thermodynamics and kinetics, but also can prompt the combination between the electrode substances and biomacromolecule with super catalysis and sensor character. It is of great significance in understanding energy conversion and metabolism in live body, biomolecular structure, various physical and chemical characters for e… 相似文献
113.
Neng Dong WANG Liu Min CHEN Sheng JIN= Xiu ZHANG Jia Hua CHEN* The Key Lab of Bioorganic Chemistry Molecular Engineering Ministry of Education China College of Chemistry Molecular Engineering Peking University Beijing 《中国化学快报》2001,(10)
The drug overdose and addiction is a serious international problem. Therefore developing a rapid, accurate, convenient and cheap method for detecting morphine in urea is useful and necessary, especially for investigation of epidemiology, identification of medical jurisprudence and determination of drug addict etc. There are many compounds that are similar to morphine in chemical structure and tend to have cross-reaction with the anti-morphine antibody. In order to reduce the cross reaction a… 相似文献
114.
Jian Guo DENG Xiao Bin DING Yu Xing PENG* Albert S. C. CHAN* Chengdu Institute of Organic Chemistry Chinese Academy of Sciences Chengdu Open Laboratory of Chirotechnology Department of Applied Biology Chemical Technology 《中国化学快报》2001,(11)
Among various conducting polymers, polyaniline (PANI) is a unique and promising candidate for practical applications because it is not only highly stable in air and in some solvents, but also exhibits dramatic changes in its electronic structure and physical properties in protoactivate state1,2,3. The carbon nanotubes (CNTs) have been proven to possess exotic properties, such as high mechanical strength, flexibility and electric conductivity. The study of carbon-based nanostructures and ma… 相似文献
115.
Jian Feng GE Li Fen ZHANG Zong Xuan SHEN Ya Wen ZHANG* Department of Chemistry Chemical Engineering Suzhou University Suzhou Department of Material Engineering Suzhou University Suzhou 《中国化学快报》2001,(7)
Mercaptoalcohols are a rare class of natural products. Some optically active mercaptoalcohols have been used as catalysts in asymmetric reduction of prochiral Ketone1,2. In this letter, we report the synthesis of a new optically active (-mercaptoalcohols, (R)-1,1-diphenyl-2-mercapto-3-methyl-1-butanol 7, from L- valine.Our first attempt is showed in Scheme 1. According to literature's method L-valine was converted to (S)-2-Hydroxy-3-methylbutanoic acid 21,2. 2 was treated with MeOH/SOCl2… 相似文献
116.
Sai Jing ZHENG Xiang Qin LIN* Department of Chemistry University of Science Technology of China Hefei 《中国化学快报》2001,(7)
Interactions of DNA with various molecules are interesting because of its importance in gene expression process of living cells. Several models for the interaction between DNA and some small molecules have been proposed1-4. We are interested in the possibility of the interaction between DNA/RNA and neurotransmitters, such as dopamine and epinephrine, because these species are very important substances for keeping normal physiological functions of brain and neuro system. However, no report… 相似文献
117.
Qing Yan CHENG Wei LI Ying ZHOU Ming Hui ZHANG Nai Jia GUAN Ke Yi TAO* Department of Material Chemistry Nankai University Tianjin 《中国化学快报》2001,(12)
The various distillation of petroleum contains arenes. For environmental protection, the hydrogenation of arenes becomes important. The amorphous alloy is a new class of material with special catalytic properties for reduction arenes1-4. In this paper, we prepared the Ni-B/TiO2 and Ni-B/Al2O3 amorphous catalysts by impregnation and reduction by KBH4 solution. Their catalytic activities for hydrogenation arenes were tested by the hydrogenation of 1,3,5-trimethylbenzene (TMB) in the co… 相似文献
118.
Guang Xing WANG Jing Xin ZHANG Shu Feng CHEN Xiao Tian LIANG* Institute of Materia Medica Chinese Academy of Medical Sciences Peking Union Medical College Beijing 《中国化学快报》2001,(3)
Chrysotricine 1 was isolated from the Chinese herb medicine Hedyotis Chrysotricha and was shown to possess antitumor activity1. Its structure has been elucidated as a novel zwitterionic (-carboline alkaloid containing a 2,2,5-trisubstituted tetrahydrofuranyl group. The (-carboline compounds have attracted considerable attraction in recent years because of their promising and intriguing biological activities2. Recently, we have established the absolute configuration of chrysotricine by the fir… 相似文献
119.
Baker's Yeast Mediated Reduction of Optically Active Diketone 总被引:1,自引:0,他引:1
Xiao Lei GAO Gang ZHOU Yu Kun GUAN Wei Dong LI Yu Lin LI* National Laboratory of Applied Organic Chemistry Institute of Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2001,(4)
Baker's yeast (BY) mediated reduction of synthetic substrate is a useful method for preparing chiral intermediate in synthesis chemistry1,2, because it is readily available and inexpensive. The selectivity is generally predicted by Prelog rule3, that is, a hydride is transferred to the re face of the prochiral ketone.The baker's yeast mediated reduction of bicyclic diketones was previously reported by several groups4-6, but to our knowledge, no application of this reduction to sesquiter-pene-… 相似文献
120.
Cheng Feng YE Ze Fu ZHANG Wei Min LIU* State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou 《中国化学快报》2001,(4)
In recent years, many efforts were focused on the preparation and characterization of phosphazene which contained a framework of alternating phosphorous and nitrogen atoms with two substituent groups attached to each phosphorous atom1. It is noticeable that cyclophosphazene, especially hexaaryloxyphosphazene and perfluoroaryloxyphosphazene exhibit excellent thermal and chemical stability which can be used as fireproof materials, high temperature lubricants, vacuum pump oils and hard disk surfac… 相似文献