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   97篇
  免费   3篇
  国内免费   3篇
化学   88篇
晶体学   2篇
力学   1篇
数学   5篇
物理学   7篇
  2022年   5篇
  2021年   3篇
  2020年   5篇
  2019年   4篇
  2018年   5篇
  2017年   3篇
  2016年   3篇
  2015年   6篇
  2014年   12篇
  2013年   23篇
  2012年   14篇
  2011年   8篇
  2010年   2篇
  2009年   3篇
  2008年   4篇
  2007年   3篇
排序方式: 共有103条查询结果,搜索用时 15 毫秒
51.
52.
53.
54.
Salbutamol, which increases the muscle mass and decreases the adipose tissue, is misused as nutrient repartitioning agent in the livestock. The novelty of this work is the determination of salbutamol in the livestock meat via new bonded-phases bearing eight derivatives of p-tert-calix[4]arene in partial-cone conformation. The new synthesized bonded-phases were characterized and optimized. The bonding interactions of solute and stationary-phases were examined and the main interactions were reported. The salbutamol levels in six samples of livestock meat were analyzed and the results reveal that for the best bonded-phases, the limit of detection(LOD) and limit of quantitation (LOQ) were 0.02 and 0.06 μg/mL, respectively.  相似文献   
55.
Dariush Souri  Kobra Shomalian 《Journal of Non》2009,355(31-33):1597-1601
Glasses with compositions (60?x) V2O5–40TeO2xSb2O3 with 0 ? x ? 10 (in mol%) have been prepared using usual melt quenching method. The position of the absorption edge and hence the values of the optical band gap was found to depend on the glass composition. Using the Tauc model, the absorption spectrum fitting method (ASF) was employed to obtain the optical band gap. This method requires only the measurement of the absorbance spectrum of the sample. For each sample, the width of the band tail was determined. Also, the density and glass transition temperature values indicate that the rigidity and packing of the samples increase with increase in Sb2O3 concentration.  相似文献   
56.
57.
Research on Chemical Intermediates - A novel copper(II)–salen complex was immobilized on the surface of magnetite nanoparticles using chitosan as a linker. This system exhibits superior...  相似文献   
58.
N‐(benzothiazol‐2‐yl)‐2‐(piperidin‐1‐yl)acetamide derivatives ( 1‐24 ) were obtained by the reaction of 2‐chloro‐N‐(benzothiazole‐2‐yl)acetamides with piperidine derivatives. The structures of the compounds were elucidated by 1H‐NMR and mass spectral data and elemental analysis. The compounds were screened for their antimicrobial activities against pathogenic bacteria and Candida species. The compounds were also investigated for their cytotoxic properties using MTT assay. The microbiological results revealed that the compounds were more effective against fungi than bacteria. Among Candida species, C. utilis was the most susceptible fungus to compounds 7 and 11 . It is apparent that 2,6‐dimethylpiperidine group and chloro and methyl substituents on benzothiazole ring have an important impact on anticandidal activity. MTT assay indicated that the effective doses of these derivatives were lower than their cytotoxic doses.  相似文献   
59.
A mild and efficient method for the oxidative deprotection of 1,3-oxathiolanes with Fe(NO33·9H2O and Cu(NO32·3H2O in the absence of solvent is reported.  相似文献   
60.
Three nano‐baskets of p‐tert‐butylcalix[4]arene‐1,2‐crown‐3 were synthesized and their binding abilities towards alkali and alkaline earth metals as well as some lanthanides were studied using differential pulse voltammetry. The novelty of this study was the investigation of macrocyclic complexes by voltammetric behaviors of two acidic moieties in each scaffold. Their voltammetric behaviors were closely related to the complex formation by entrapment of cation into crown ether cavity and ion‐dipole interaction between cation and acidic moieties in calixcrowns. The results revealed that the sulfur atom in the crown ring as well as the position of crown‐3 ether in 1,2‐alternate instead of cone conformer changed the binding ability of the scaffold to more cations.  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