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   70篇
  免费   3篇
  国内免费   1篇
化学   55篇
数学   4篇
综合类   15篇
  2021年   2篇
  2016年   2篇
  2015年   4篇
  2014年   4篇
  2010年   1篇
  2009年   2篇
  2008年   6篇
  2007年   1篇
  2006年   18篇
  2005年   21篇
  2004年   2篇
  2003年   2篇
  2002年   1篇
  2001年   1篇
  2000年   2篇
  1999年   3篇
  1997年   1篇
  1996年   1篇
排序方式: 共有74条查询结果,搜索用时 15 毫秒
1.
1 INTRODUCTION donor due to the presence of the protonated carboxyl group; (d) it can form short bridges via one car- Coordination polymers are of great interest due to boxylato end or long bridges via the benzene ring[7]. their physical properties and potential applications in We believe that coordination functionality of isoph- functional materials[1~3]. Aromatic polycarboxylic acids thalate can lead to interesting structures. In this com- such as 1,2,4,5-benzenetetracarboxylic acid[4],…  相似文献   
2.
1 INTRODUCTION The construction and characterizations of low dimensional inorganic/organic hybrid materials have increasingly attracted the interest of chemists duo to their unusual topologies and relevance in a wide range of applications in materials science including transport, magnetic materials, catalysts, and lumi- nescent materials[1]. Among the various families of hybrid functional materials, the family of metal halides is an important one. As a branch of the metal halides, silver(…  相似文献   
3.
1 INTRODUCTION Recently, the organic-inorganic hybrid Ⅳa groupmetal halides with low-dimensional structure haveattracted much attention of chemists and physicistsdue to their particular properties and applications.For example, they are akin to “natural quantum-well”architectures and have tunable excitonic propertiesusually governed by the inorganic substructure andorganic component[1]; they have been applied assome technologically important materials, such assemiconductor materials in …  相似文献   
4.
1 INTRODUCTION Recently, the low-spin square-planar nickel(II) complexes and high-spin octahedral nickel(II) complexes with Schiff base ligands have received much attention in optical materials[1~3]. Some nic- kel(II) complexes are widely used as lubricating oil, rubber industry additives, a fire-resistant additive and fungicide for leather[4~7]. Also, their adducts with nitrogen have attracted broad attention due to their potential applications as organic conductors and magnetic mate…  相似文献   
5.
1 INTRODUCTION The picoloylhydrazide compounds are close to thebiologic environment and can react with microele-ments in organism so as to have antitubercular andantineoplastic activities. However, owing to the exis-tence of amino group, this kind of compounds aretoxic to some extent[1]. In order to decrease theirtoxicity, hydrazone or hydrazide compounds synthe-sized by the condensation reaction of amino and car-bonyl groups have been well studied in recentyears[1~7]. Herein we report t…  相似文献   
6.
ZHANG Yu① 《结构化学》2005,24(4):462-466
1 INTRODUCTION AIDS, in other words, Acquired Immunodefici-encysyndrome, is a viral contagious disease withhigh death rate. However, effective treatment againstit has not appeared so far. At present, about 100kinds of natural compounds that could be extractedfrom natural products or artificially synthesized havebeen found to have anti-HIV activities to some ex-tent. They belong to flavonoid, terpenoid, steroid, cou-marin, peptide, alkaloid etc., respectively. Previousstudies show that…  相似文献   
7.
海底电缆(ocean bottom cable,OBC)地震勘探是浅海石油地震勘探的主要勘探方法。首先,分析了当前OBC地震勘探作业采用的导航系统存在的问题,并提出了一种新的不仅包含放缆导航作业、电缆定位及野外地震资料采集能力,还满足安全管理需要的系统总体设计和多船分布式设计方案。阐明了系统应包含的中央集中控制和远程控制,地震同步采集控制等主要功能。通过野外应用表明:研制完成的新系统提高了野外作业同步采集精度,实现了船队内部的数据共享和可视化管理,满足了统一生产指挥及安全管理的需要。  相似文献   
8.
1 INTRODUCTION Since the introduction of QSAR by Hansch and Fujita in 1964, Deutsch and Hansch have quickly used it in the study of nitrophenylamine sweet reagents. They found good correlation between their distribution coefficients in octanol/water system and sweetness degree. Subsequently, they detected that vibration of aroma-substituent compounds has so- mething to do with sweetness. Henceforth, statistic correlations between structure and sweetness ofseries compounds have been inv…  相似文献   
9.
1 INTRODUCTION After Guo[1] synthesized and detected C60-nBn and C70-nBn by mass spectra, investigations on fullerenes doped by other atoms became more and more interesting. Andreoni[2] studied the impurity states of the doped fullerenes C59B; Dong[3] calculated the structural and electronic properties of C59B; Wang[4] assessed the stability of heterohedral fullerenes C60-xBx. Lamparth[5] prepared C59N and C69N , and put forward the possible structures for C59N . Sahoo[6] obtained…  相似文献   
10.
The title Schiff base compound 4-bromo-2-[(3-methylpyridin-2-ylimino)methyl]phenol was prepared and structurally characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal belongs to monoclinic, space group P2 1/n, with a = 4.4870(9), b = 19.953(4), c = 13.860(3)A, β = 93.13(3)°, V = 1239.0(4)A3 Z = 4, Dc = 1.561 g/cm3, C13H11BrN2O2 , Mr = 291.15, p = 3.302 mm-1 and F(000) = 584. The final refinement gave R = 0.0608 and wR = 0.1377 for 1329 observed reflections with I 〉 2σ(I). X-ray diffraction reveals that the non-hydrogen atoms in the compound are nearly coplanar, with the mean deviation of 0.0197A from the plane. The molecule adopts an E configuration about the central C=N functional bond. The compound possesses moderate antimicrobial property.  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