排序方式: 共有139条查询结果,搜索用时 15 毫秒
21.
22.
23.
ZnO nanorods prepared by a solution-phase method are annealed at different temperatures in oxygen ambient.The luminescence properties of the samples are investigated.In the same excitation condition,the photoluminescence(PL) spectra of all samples show an ultraviolet(UV) emission and a broad strong visible emission band.The asymmetric visible emis-sion band of annealed samples has a red-shift as the annealing temperature increasing from 200 ℃ to 600 ℃ and it can be deconvoluted into two subband emissions centered at 535 nm(green emission) and 611 nm(orange-red emission) by Gaussian-fitting analysis.Analyses of PL excitation(PLE) spectra and PL spectra at different excitation wavelengths reveal that the green emission and the orange-red emission have a uniform initial state,which can be attributed to the electron transition from Zn interstitial(Zni) to oxygen vacancy(Vo) and oxygen interstitial(Oi),respectively. 相似文献
24.
以大面积喷淋式平板电极甚高频等离子体增强化学气相沉积(VHF-PECVD)反应室为研究对象,利用FlexPDE和CFD-ACE+商业软件,对反应室电极间的电场和流场分布进行了数值模拟。根据数值模拟结果可知:对于大面积喷淋式平板电极VHF-PECVD反应室,电极间气体流速分布呈现管流特征,而气压分布和电场分布具有类似的分布规律,即在大面积电极中央区域电场较强气压较高,而电极边缘区域电场较弱气压较低;另外,反应室采用喷淋式平板电极进行反应气体馈入,气体总流量、工作气压和电极间距是调节电极间气压分布均匀性的重要参量,采用大电极间距、高工作气压,以及小的气体总流量有助于获得均匀的气压分布。 相似文献
25.
采用自制静电探头测量经60Co伽玛线辐射源辐射的聚萘二甲酸丁二醇酯(PBN)试样的表面电荷密度,分析辐射量对试样表面电荷特性的影响。实验结果表明,随着施加负直流电压时间的延长,试样表面电荷平均密度增大;随着辐射量的增加,表面电荷平均密度降低。认为伽玛线辐射引起的交联反应使表面态密度降低,是造成PBN带电能力下降的主要原因。 相似文献
26.
提出一种拟合模态法进行动力学建模,把大型有限元分析软件计算得出的模态拟合成为多项式的形式,得到曲线梁的近似解析表达式,从而大大简化了建模与计算的过程.以某型号卫星抛面天线为例,验证了方法的可行性与准确型. 相似文献
27.
28.
29.
The aim of this study was to obtain a better understanding of the range of organic molecular weight(MW)causing membrane fouling through the comparison between direct UF and in-line coagulation(without settling)/UF process.The experimental results indicated that,when raw water with organics was treated and the MW of more than half of the organics was less than 1 kDa,membrane fouling was rather serious by only UF and coagulation could improve the fouling for the treatment of raw water.Besides,coagulation/UF could remove organics in each region,and organics with MW greater than 30 kDa were the most possible matters causing membrane fouling,while organics with MW less than 1 kDa were impossibly responsible for membrane fouling due to few organics removed.Therefore,organics with MW greater than 30 kDa were the major factor of membrane fouling. 相似文献
30.
半导体生产线是目前世界上公认的最复杂的制造系统,刻蚀设备是半导体晶圆制造过程中最复杂的系统,刻蚀设备的调度算法是系统生产管理控制的核心功能。目前国内大多数的研究都是针对于fab级别的任务调度,而针对单独的刻蚀设备的优化算法的研究很少。在此,笔者提出了一种基于规则的实时晶圆调度算法,力求实现生产周期缩短、提高设备产能的目标。 相似文献