排序方式: 共有28条查询结果,搜索用时 15 毫秒
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分析了金阴极微通道板在X射线段(0.1~10 keV)的能谱响应,从阴极量子效率,X射线在通道材料中的衰减,微通道壁的铅层的光电效应,微通道板通道增益等多个方面进行综合计算,结果表明:得出较完善的阴极型微通道板能谱响应理论公式及其数值模拟曲线.在只考虑一个通道,增益值为1时,微通道板的能谱响应完全取决于金阴极的量子效率,若考虑多通道效应,微通道板的能谱响应受通道材料元素吸收边的影响发生突变,且通道数目越多,影响越显著;能谱响应随电压增大呈增长趋势,但会受到微通道板饱和电流的限制.实验给出了微通道板能谱响应与入射角的关系曲线,确定了能获得增益的最小入射角. 相似文献
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对ICF实验中条纹相机的重要组件变像管的工作过程进行了介绍,建立了其内部电子光学系统模型,对其静态电子光学特性进行了数值模拟。模拟软件采用ANSYS,数值计算基于有限元数值计算方法,并利用哈密顿原理求解泛函,在控制计算精度的基础上,得出了该电子光学系统的内部静电场分布和轴上电位分布,同时对静态条件下的电子轨迹进行了模拟计算。结果显示了与理论解析结果很好的相似性,同时初步探索了电极尺寸及电压参数对成像的影响。结果表明,电压参数的改变对光电子成像的影响要更大一些。 相似文献
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Influence of Concentration of Vanadium in Zinc Oxide on Structural and Optical Properties with Lower Concentration 下载免费PDF全文
ZnO films doped with different vanadium concentrations are deposited onto glass substrates by dc reactive magnetron sputtering using a zinc target doped with vanadium. The vanadium concentrations are examined by energy dispersive spectroscopy (EDS) and the charge state of vanadium in ZnO thin films is characterized by x-ray photoelectron spectroscopy. The results of x-ray diffraction (XRD) show that all the films have a wurtzite structure and grow mainly in the c-axis orientation. The grain size and residual stress in the deposited films are estimated by fitting the XRD results. The optical properties of the films are studied by measuring the transmittance. The optical constants (refractive index and extinction coefficient) and the film thickness are obtained by fitting the transmittance. All the results are discussed in relation with the doping of the vanadium. 相似文献
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本文通过建立有机工质/DMF混合工质相平衡计算模型,对比了纯R245fa和其与DMF的混合物二者对有机朗肯循环中膨胀机做功的影响。其结果表明,在膨胀机进出口压比受限的情况下,利用R245fa/DMF的特殊物性,改变R245fa的液相摩尔分数,可在获得高蒸气温度的同时降低相平衡压力,并在同压比条件下获得更高的膨胀机进出口焓差,当R245fa的液相摩尔分数为0.64,温度为403 K时,焓差较纯质时由19.2 kJ/kg增大至22.84 kJ/kg;此外采用混合工质时的热效率较同压比时的纯工质高06%~1.3%。 相似文献
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耦合吸附吸收制冷系统设计及性能预测 总被引:1,自引:0,他引:1
耦合吸附吸收制冷系统(ADAB)具有运行压力接近常压的优点。本文针对以往的耦合系统设计中存在的问题, 设计了新型的耦合吸附吸收制冷系统。本文系统充分考虑了氨水溶液由吸收状态向发生状态切换时的显热损失问题,通过发生器和吸收器的分离设计,部分避免了由于切换时氨水溶液显热损失导致的系统制冷量减少甚至无冷量问题。本文对此新型系统的运行特性进行了理论研究,对其制冷性能进行了分析预测。分析结果表明该系统在蒸发温度5℃的空调工况下,系统性能系数GOP为0.18;若吸附制冷循环能够在40 min内完成,则新型系统的比吸附剂制冷量SGP为40.8 W/kg。 相似文献
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Simultaneous determination of trap depth and the ratio of the rate of recombination to that of capture from thermo-luminescence 下载免费PDF全文
Thermo-luminescence (TL) is a kind of luminescence decay measured with
varying temperature. In the process of TL the decay parameter itself
involves the temperature effect of traps. Thus the trap depth is inseparable
from the decay parameter. There are two separate peaks in the TL curve of
ZnS:Cu,Co if the measurement starts from liquid nitrogen temperature. In the
experiment we started from zero Celsius temperature to isolate the deeper
traps. We have proposed and realized three methods for simultaneous
determination of trap depth and decay parameter based on the
quasi-equilibrium model and experimental data. If we treat the case of
kinetic order \alpha =1 as \alpha =2, the error might be as large as
100%. 相似文献