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   8篇
  免费   4篇
  国内免费   1篇
数学   3篇
物理学   10篇
  2005年   1篇
  2004年   5篇
  2003年   4篇
  2000年   1篇
  1995年   2篇
排序方式: 共有13条查询结果,搜索用时 437 毫秒
1.
新型噁二唑有机电致发光小分子光电性质研究   总被引:2,自引:2,他引:0  
通过升降温差热分析(DSC)曲线、偏光显微镜、紫外吸收光谱、电化学行为曲线以及多层器件等,研究了噁二唑衍生物小分子的电学和光学性质,发现其同时具有液晶性、电子和空穴传输性、发光性等优良性能.引进R-OXD(En)层后的多层器件在低于3 V时就能得到可见光发射,在7 V时可以得到光亮度为1000 cdm-2.此系列小分子可降低有机电致发光器件开启电压,提高发光亮度和发光效率,是一种非常具有吸引力的有机电致发光小分子.  相似文献   
2.
数学教学开放的教学模式是世界数学教学的新趋势.1998年8月,在韩国召开的第一届东亚国际数学教育大会上,有许多专家提到“开放题”(open—endedproblem)和“开放教学方法”(open—endedteachingapproach).本文就这两个问题谈点看法.1 数学开放题对数学开放题的传统认识只有结论开放一类.随着各国数学教育工作者对数学开放题的认识逐步加深,现已发展为结论开放、条件开放、推理开放及问题本身开放几大类.1.1 结论开放题,即指没有唯一确定答案的问题.例如,日本横滨国立大学教授桥本吉彦设计的“水槽问题”是值得我们多加体会的.这个问题是这…  相似文献   
3.
Room-temperature Raman and PL spectra, photocurrent (PC) and thermally stimulated current (TSC) were measured to investigate the mid-gap defects in diamonds grown by using a hot-filament chemical vapour deposition (CVD) technique. The [Si-V]^0 centres caused by the Si-C bonds in diamond grains and at grain boundaries are located at 1.68eV. We firstly detect the level 1.55eV by using PL and it is tentatively attributed to the zero-phonon luminescence line or vibronic band of the [Si-V]^0 induced by the Si-O bonds. The 2.7-3.2eV and 1.9-2.1 eV PC peaks were detected and discussed. The IN-V] complex may be attributed to these defect levels.Some shallow energy levels lower than 1.0eV were also observed in the CVD diamond.  相似文献   
4.
遵循教学规律 突破立体几何入门教学的关键张明龙(江苏吴江师范215200)立体几何是研究空间图形的性质、画法、计算以及它们的应用的学科,立体几何课虽是在初中平面几何的基础上开设,然由于多种原因,初学立体几何的学生往往感到不适应,困难较大,如何在教学过...  相似文献   
5.
Diamond films with [100] texture were prepared by a hot-silament chemical vapour deposition technique to fabricate particale detectors.the response of detectors to 5.5MeV^241 am particles is studied.The photocurrent increases linearly and then levels off with voltage,and 7nA is obtained at bias voltage of 100V.The timedependent photocurrent initially increases rapidly and then tends to reach saturation.Furthermore,a little increase of the dark-current after irradiation can be accounted for by the release of the charges captured by the trapping centres at low energy levels during irradiation.An obvious peak of the pulse height distribution can be observed,associated with the energy of 5.5MeV.  相似文献   
6.
Spectroscopic ellipsometric measurements in infrared region (2.5 - 12.5 μm) are carried out to characterize the structure and quality of diamond films grown by microwave plasma chemical vapor deposition (MPCVD) and hot filament chemical vapor deposition (HFCVD), respectively. It is found that the establishment of appropriate models has the strongest influence on the fit of ellipsometric spectra. The best fit is achieved for MPCVD film with a 77.5-nm middle layer of SiO2, and for HFCVD film with an 879-nm rough surface layer included by Bruggeman effective medium approtimation (EMA). Finally the refractive index and the extinction coefficient are calculated for both films, the results show that the film grown by MPCVD is optically much better than that grown by HFCVD at infrared wavelengths.  相似文献   
7.
微条气体室(Micro-strip Gas Chamber,MSGC)探测器最严重的问题是电荷积累效应,通过选择合适的衬底材料可以有效的避免.为此,D263玻璃上沉积类金刚石(Diamond-like Carbon,DLC)膜来进行表面改性,从而制备DLC膜D/263玻璃双层结构作为MSGC衬底.拉曼光谱说明DLC膜是由sp3(σ键)和sp2(π键)杂化碳原子组成,属于电子导电型材料,并且沉积出的是一种高质量的DLC膜;I V曲线表明DLC膜改性后的样品具有非常稳定和理想的电阻率,其值在109—1012Ω·cm间;C-F曲线显示改性后样品具有小而稳定的电容.DLC膜D/263玻璃的优良性能正是MSGC衬底的最佳要求,这种新型材料用作衬底将有效克服电荷积累效应和衬底不稳定性.  相似文献   
8.
生长条件和退火对金刚石薄膜光学性质的影响   总被引:2,自引:1,他引:1  
提出一种分析微波等离子体化学气相沉积工艺条件对金刚石薄膜的组成和光学性质影响的方法。采用红外椭圆偏振光谱仪来分析Si衬底上金刚石薄膜的组成和光学性质,研究微波等离子体化学气相沉积法生长条件和退火工艺对金刚石薄膜的消光系数和折射率的影响。实验表明金刚石薄膜中存在C—H、C=C、O—H和C=O键,生长条件对薄膜中C—H和C=C键的含量及薄膜的折射率影响较大;薄膜经过退火后薄膜的光学性质得到明显改善。  相似文献   
9.
Study for infrared spectroscopic ellipsometric properties of diamond films   总被引:1,自引:0,他引:1  
Spectroscopic ellipsometric measurements in infrared region (2.5 - 12.5 μm) are carried out to characterize the structure and quality of diamond films grown by microwave plasma chemical vapor deposition (MPCVD) and hot filament chemical vapor deposition (HFCVD), respectively. It is found that the establishment of appropriate models has the strongest influence on the fit of ellipsometric spectra. The best fit is achieved for MPCVD film with a 77.5-nm middle layer of SiO2, and for HFCVD film with an 879-nm rough surface layer included by Bruggeman effective medium approtimation (EMA). Finally the refractive index and the extinction coefficient are calculated for both films, the results show that the film grown by MPCVD is optically much better than that grown by HFCVD at infrared wavelengths.  相似文献   
10.
金刚石薄膜的红外椭圆偏振光谱研究   总被引:3,自引:0,他引:3       下载免费PDF全文
采用红外椭圆偏振光谱对微波等离子体化学气相沉积法(MPCVD)和热丝化学气相沉积法(H-FCVD)制备的金刚石薄膜在红外波长范围(2.5—12.5μm)的光学参数进行了测量.建立了不同的光学模型,且在模型中采用Bruggeman有效介质近似方法综合考虑了薄膜表面和界面的椭偏效应.结果表明,MPCVD金刚石膜的椭偏数据在模型引入了厚度为77.5nm的硅表面氧化层、HFCVD金刚石膜引入879nm粗糙层之后能得到很好的拟合.最后对两种模型下金刚石薄膜的折射率和消光系数进行了计算,表明MPCVD金刚石薄膜的红外 关键词: 金刚石薄膜 红外椭圆偏振光谱 光学参数 有效介质近似  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