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   207篇
  免费   9篇
  国内免费   1篇
儿科学   1篇
妇产科学   2篇
基础医学   36篇
口腔科学   5篇
临床医学   22篇
内科学   26篇
皮肤病学   2篇
神经病学   15篇
特种医学   4篇
外科学   17篇
综合类   3篇
预防医学   55篇
眼科学   2篇
药学   20篇
肿瘤学   7篇
  2024年   1篇
  2023年   1篇
  2022年   5篇
  2021年   23篇
  2020年   3篇
  2019年   6篇
  2018年   8篇
  2017年   5篇
  2016年   11篇
  2015年   3篇
  2014年   7篇
  2013年   8篇
  2012年   17篇
  2011年   26篇
  2010年   10篇
  2009年   11篇
  2008年   9篇
  2007年   12篇
  2006年   12篇
  2005年   8篇
  2004年   5篇
  2003年   7篇
  2002年   10篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1991年   1篇
  1985年   1篇
  1984年   1篇
  1979年   1篇
  1976年   1篇
排序方式: 共有217条查询结果,搜索用时 765 毫秒
1.
Genetic diversity was characterized in 20 isolates of Grapevine fanleaf virus (GFLV) recovered from naturally infected grapevine plants (Vitis vinifera) in the North of Tunisia. Viral RNAs were isolated by oligoprobe capture, and a 605 bp fragment containing a part of the viral coat protein gene was amplified by RT-PCR. Sequence variation among isolates was characterized by restriction fragment length polymorphism (RFLP) analysis and confirmed by sequencing. The GFLV infections are found as a complex mixture of closely related genomes. In further studies, RFLP analyses of virus isolates using AluI showed that GFLV populations in Tunisian vineyards consist of two restrictotypes corresponding to distinct sub-populations Sp1 and Sp2. The relative field distribution of these sub-populations showed that Sp2 was more abundant. Individual genomes were recovered by cloning the RT-PCR products. The sequences were found to vary from each other by as much as 11%. Cloning from mixed infections showed that Sp2 are also predominant.  相似文献   
2.
International Urology and Nephrology - Biomarkers for the diagnosis and monitoring treatment response of kidney cancer are urgently needed. Neutrophil gelatinase-associated lipocalin (NGAL) is a...  相似文献   
3.
4.
5.
6.
7.
8.
9.
10.
This work is devoted to the synthesis and study of the different properties of ZnO nanoparticles (NPs) doped with the Ni element. We have used a simple co-precipitation technique for the synthesis of our samples and various structural, morphological and optical techniques for their analysis. Energy-Dispersive X-ray spectroscopy (EDX) confirms the stoichiometry of the samples. The X-Ray Diffraction (XRD) patterns reveal the hexagonal wurtzite phase of polycrystalline ZnO with a P63mc space group. Debye Scherrer and Williamson–Hall methods show that the average size of crystallites is around 40 nm. Transmission electron microscopy (TEM) images confirm the XRD results. The optical spectrum of Zn0.95Ni0.5O shows the presence of near-band-edge (NBE) ultraviolet emission. The absorption defect bands appearing near the blue–green region and near infrared emission are attributed to the Ni2+ intra-3d luminescence. The electronic structure of the Ni2+ doped ZnO NPs confirms the Td site symmetry of Ni2+ in the ZnO host crystal and leads to a perfect correlation between calculated and experimental energy levels.

This work is devoted to the synthesis and study of the different properties of ZnO nanoparticles (NPs) doped with the Ni element.  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