全文获取类型
收费全文 | 535篇 |
免费 | 55篇 |
国内免费 | 91篇 |
专业分类
化学 | 546篇 |
力学 | 21篇 |
综合类 | 5篇 |
数学 | 40篇 |
物理学 | 69篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 6篇 |
2018年 | 6篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2014年 | 32篇 |
2013年 | 46篇 |
2012年 | 45篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 22篇 |
2007年 | 21篇 |
2006年 | 16篇 |
2005年 | 19篇 |
2004年 | 31篇 |
2003年 | 38篇 |
2002年 | 88篇 |
2001年 | 197篇 |
2000年 | 35篇 |
1999年 | 24篇 |
1998年 | 11篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1990年 | 2篇 |
1988年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有681条查询结果,搜索用时 15 毫秒
1.
Jing Lin CHEN Gang Qiang YIN Zhong Ning CHEN* State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Fuzhou 《中国化学快报》2003,(5)
Great attention is currently paid to the synthesis of polynuclear transition metal complexes as well as their photochemical, photophysical, and electrochemical properties. The design of multicomponent systems capable of performing useful light- and/or redox-induced function is of special interest1. The oxo-centered carboxylate-bridge trinuclear ruthenium clusters have been investigated extensively during recent decades because they have remarkable electron-transfer properties, intense visibl… 相似文献
2.
Jing Ping WANG Qiang WU Jing Yang NIU* School of Chemistry Chemical Engineering Henan University Kaifeng 《中国化学快报》2002,13(9):915-918
It is becoming a focus to synthesize and assemble organic-inorganic materials, especially, to synthesize charge-transfer complexes formed by polyoxometalate and organic donors. They have attracted much attention because such complexes are active in their electric, magnetic and optic properties1-4, many investigations about them have been done and some crystal structures of them were reported5-6. But, the disadvantage of these crystals is instability at room temperature. According to the view… 相似文献
3.
Chun Chun ZHANG Wei ZENG Jian Zhang LI Sheng Ying QIN* Department of Chemistry Sichuan University Chengdu 《中国化学快报》2003,(6)
It is well known that the study on biomimetic oxygen carriers not only has important theoretic significance to discover the mechanism of reversible bonding, activating oxygen as well as the oxidation reaction in organism, but also has potential application in separating oxygen from air and realizing the high efficiency and selectivity of catalytic oxidation reaction under a mild condition1. Metal- porphyrin and metal- phthalol- gaunine have been extensively used as biomimetic oxygen carriers u… 相似文献
4.
You Liang ZHAO Chuan Fu CHEN Fu XI* State Key Laboratory of Polymer Physics Chemistry Center for Molecular Science Institute of Chemistry Chinese Academy of Sciences Beijing 《中国化学快报》2002,13(5):420-421
Much effort has been dedicated to the molecular design and synthesis of model proteins to define protein folding interactions and to develop protein-based materials. Among them, the ring-opening polymerization of -amino acid-N-carboxyanhy- drides (NCAs) has drawn much attention because the resulting artificial polypeptides have wide applications in biotechnology, biomineralization and diagnostics1, 2. It is well known that dendrimers are hyperbranched macromolecules possessing a very high co… 相似文献
5.
Nan Yan FU Mei Li PANG Yao Feng YUAN Ji Tao WANG* Department of Chemistry National Key Laboratory of Elemento-organic Chemistry Nankai University Tianjin 《中国化学快报》2002,13(10)
A highly efficient catalyst indium (III) tribromide is used to synthesize 5-alkoxy- carbonyl-4-hydrocarbyl-3,4-dihydropyrimidin-2(1H)-ones by a three-component coupling of β-keto ester, aldehydes and urea through improved Biginelli reaction. 相似文献
6.
Yi Xin ZHAO Shu Guang WANG* School of Chemistry Chemical Technology Shanghai Jiaotong University Shanghai 《中国化学快报》2005,(11)
The increasing demand to produce enantio-pure pharmaceuticals, flavors, and other fine chemicals has advanced the field of asymmetry catalytic technologies. Among all asymmetry catalytic methods, catalytic enantioselective hydrogenation of unsaturated bonds such as olefins, ketones, and imines, which employs dihydrogen and small amounts of transition-metal complexes modified intrinsically by chiral ligands, is now recognized as being the most promising strategy for the synthesis of large amount… 相似文献
7.
Qing LI Hui LI Bin SU Xiang Bao MENG Meng Shen CAI Zhong Jun LI* Department of Chemical Biology School of Pharmaceutical Sciences National Research Laboratory of Natural Biomimetic Drugs Peking University Beijing 《中国化学快报》2002,13(4):303-305
Our previous paper1,2reported the results of selective synthesis of mannose type glycosides and their dimers in our attempt to synthesize derivatives of N-acetyllacto- samine, which could have potential activity of anti-metastasis3. Further studies on the glycosylation of the accepters exploiting glycosyl nitrate instead of the acetate as donor showed interesting chemoselectivity between the two kinds of donor, namely, the glucose type and the mannose type. The reactivity difference of the t… 相似文献
8.
在JP10和煤油点火特性激波管实验的基础上,实验研究了硅烷对这两种典型高碳数碳氢燃
料点火特性的影响. 在预加热到70 C的激波管上,采用缝合运行条件获得了近7ms
的实验时间,将实验延伸至低温区. 采用气相色谱分析和高精度真空仪直接测定压力相结合
的方法,确定了燃料气相浓度,解决了高碳数碳氢燃料点火激波管实验时由于管壁吸附影响
燃料气相浓度确定的困难. 实验记录了点火过程中OH自由基发射强度变化,并作为判断点
火发生的标志. 实验温度范围880~1800K, 压力范
围0.16~0.53\,MPa. 当硅烷加入量约为燃料的10%~15%(摩尔比),
质量比为2%~3%, 观测到明显的点火促进作用. 该研究对超燃研究中发动机设计、
燃料选择等方面具有直接的工程意义,也可用于检验燃烧化学动力学模型的合理性. 相似文献
9.
对于中国学术界出版英文学术期刊现在是没有人反对的,而且一般地讲大家都会赞成要把它办好。但是对于在中国出版英文期刊的目的和作用,对于这些刊物和刊物论文的评价尺度、以及对于办刊的回报预期,从论文作者到读者,从出版社到相关的主管机构(如中国科学技术协会及其下属学会、国家自然 相似文献
10.
Kun Guo YANG Rui Mao HUA* Hai WANG Bo Qing XU* Department of Chemistry Tsinghua University Key Laboratory of Organic Optoelectronics & Molecular Engineering of Ministry of Education Beijing Department of Chemistry Chemical Engineering Guangxi Normal University Guilin 《中国化学快报》2005,16(4)
Diphenylmethane and substituted diphenylmethane are important compounds forsynthesis chemistry as well as industrial chemistry. These compounds are easilysynthesized by the benzylation of aromatic compounds with benzyl chloride or benzylalcohol catalyzed by homogeneous acid catalysts, such as AlCl3, FeCl3, H2SO4, HF andBF3. However, these catalytic systems are highly corrosive, and usually proceed withlow selectivity. In addition, they are less satisfactory from the environmen… 相似文献