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   28篇
  免费   2篇
化学   2篇
数学   5篇
物理学   23篇
  2018年   1篇
  2014年   1篇
  2013年   1篇
  2011年   1篇
  2009年   1篇
  2008年   1篇
  2004年   2篇
  2003年   1篇
  2002年   1篇
  2000年   1篇
  1999年   2篇
  1996年   1篇
  1994年   1篇
  1992年   3篇
  1990年   1篇
  1986年   2篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
排序方式: 共有30条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Surface photovoltage spectroscopy, Auger electron spectroscopy, LEED, X-ray and ultraviolet photoemission measurements are reported for (112̄0) CdSe under a variety of ultrahigh vacuum conditions. As with CdS, all surface electronic features can be related to chemical contamination, Ar+ bombardment-induced lattice defects, or bulk trap states. Oxygen adsorption on CdSe and CdS produce qualitatively different electronic features which are attributed to different bonding at surface vacancy sites. Changes in surface atomic order show no direct effect on measured electronic features. Furthermore, CdSe exhibits no intrinsic surface state features which can account for its Schottky barrier formation with metals.  相似文献   
5.
Energy loss spectra of low energy electrons (ELS) have been obtained for thin solid films of tetracyanoquinodimethane (TCNQ), tetrathiafulvalene (TTF), and the charge transfer salt TTF-TCNQ as a function of incident energy (20 to 100 eV). The incident energy dependence of energy loss features allows the identification of triplet and symmetry forbidden excitations in TCNQ and TTF. The ELS spectrum of TTF-TCNQ is compared with high energy electron loss data to show that the surface of evaporated films of TTF-TCNQ contains 20–50% neutral TCNQ molecules.  相似文献   
6.
Semi-insulating Gallium nitride was irradiated by fast and thermal neutrons with fluences from 1014 to 1016 n/cm2. Depth-resolved cathodoluminescence spectroscopy was used to determine defects changes before and after irradiation. The results revealed two kinds of defects affected near-band emission recombination from two opposite directions. One was attributed to irradiation-induced N vacancies that contribute to near-band emission recombination. Another was attributed to irradiation-induced deep level defects that contribute to sub-band gap recombination and thus decrease the near-band emission recombination.  相似文献   
7.
8.
9.
A new diiodine substituted IDA derivative, 2,4-diiodine-6-methyl IDA (DIIODIDA) was synthesized and labeled with99mTc. It was established that99mTc-DIIODIDA had high radiochemical purity. Biodistribution and influence of bilirubin on99mTc-DIIODIDA biokinetics has been studied in rats and compared to the corresponding results for99mTc-SOLCOIODIDA. Related to99mTc-SOLCOIODIDA,99mTc-DIIODIDA has much better biliary exretion (55.18 versus 43.63%). No change of99mTc-DIIODIDA biokinetics, under influence of bilirubin was noticed. Biliary excretion of99mTc-SOLCOIODIDA has been reduced for about 60%. The protein binding of99mTc-DIIODIDA and99mTc-SOLCOIODIDA were also determined, using in vitro method of precipitation. These results showed that99mTc-DIIODIDA hepatobiliary imaging agent is superior to the presently used99mTc-monoiodine IDA derivatives.  相似文献   
10.
章新友  L.J. Li  黄永畅 《物理学报》2014,63(19):190301-190301
本文获得了有各种相互作用的一般n阶特征量泛函,其耦合系数反映了不同特征量泛函之间的耦合强度.依据定量因果原理,导出了一般n阶特征量泛函的变分原理,获得了一般n阶特征量泛函的Euler-Lagrange方程,它的不同系数可拟合不同的物理现实,如从线性到任意n阶非线性物理系统,使复杂难解的任意n阶非线性物理系统变得具体可解.并获得了该对称变换下不变的m个的守恒量,以及它们之间的关系和统一描述.依据定量因果原理导出了相对性原理,证明了绝对加速参考系、牵连参考系和相对参考系的力都有来自加速度和质量变化的贡献.利用定量因果原理自然导出了广义牛顿第一定律和广义牛顿第二定律,而且还导出了一个新定律,即广义牛顿第三定律,亦即平移不变性系统合力为零定理.进而将研究结论应用于对银河系的修正引力势、分子势、夸克禁闭势等,且其结果与物理实验一致.  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