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71.
分别用连续波1.319μm激光和10.6μm激光辐照PC型HgCdTe红外探测器时,得到了不同辐照光功率密度下,探测器输出的一系列实验结果。给出了在波长为1.319μm的波段内激光辐照下PC型HgCdTe探测器的饱和阈值;用波长为10.6μm的波段外CO2激光辐照探测器时,发现了一些与波段内激光辐照探测器时大不相同的实验现象;对实验结果进行了分析。简要总结了PC型HgCdTe探测器对于波段内和波段外激光辐照的响应机制。 相似文献
72.
用射频磁控共溅射法制备了Cu体积分数分别为 10 % ,15 % ,2 0 %和 3 0 %的Cu MgF2 复合金属陶瓷薄膜 .用x射线衍射、x射线光电子能谱和变温四引线技术对薄膜的微结构、组分及电导特性进行了测试分析 .微结构分析表明 :制备的Cu MgF2 复合薄膜由fcc Cu晶态纳米微粒镶嵌于主要为非晶态的MgF2 陶瓷基体中构成 ,Cu晶粒的平均晶粒尺寸随组分增加从 11 9nm增至 17 8nm .5 0— 3 0 0K温度范围内的电导测试结果表明 :当Cu体积分数qM 由 15 %增加到 2 0 %时 ,Cu MgF2 复合薄膜的电阻减小了 8个量级 ,得出制备的复合薄膜渗透阈qCM 应处于 15 %和 2 0 %之间 .qM 在 10 %和 15 %之间的薄膜呈介质导电状态 ,而在 2 0 %和 3 0 %之间的薄膜则呈金属导电状态 .从理论上讨论了复合薄膜中杂质电导和本征电导的激活能及其对电导的贡献 ,并讨论了Cu MgF2 复合纳米金属陶瓷薄膜的渗透阈 ,得到了和实验一致的结果 相似文献
73.
An alternative discretization of pressure‐correction equations within pressure‐correction schemes for the solution of the incompressible Navier–Stokes equations is introduced, which improves the convergence and robustness properties of such schemes for non‐orthogonal grids. As against standard approaches, where the non‐orthogonal terms usually are just neglected, the approach allows for a simplification of the pressure‐correction equation to correspond to 5‐point or 7‐point computational molecules in two or three dimensions, respectively, but still incorporates the effects of non‐orthogonality. As a result a wide range (including rather high values) of underrelaxation factors can be used, resulting in an increased overall performance of the underlying pressure‐correction schemes. Within this context, a second issue of the paper is the investigation of the accuracy to which the pressure‐correction equation should be solved in each pressure‐correction iteration. The scheme is investigated for standard test cases and, in order to show its applicability to practical flow problems, for a more complex configuration of a micro heat exchanger. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
74.
Chung-Cherng Lin 《Journal of Physics and Chemistry of Solids》2004,65(5):913-921
The phase transition of a synthetic clinoenstatite in a diamond-anvil cell has been studied by using Raman spectroscopy at various pressures and room temperature. The phenomena observed in clinoenstatite have been compared with that observed in orthoenstatite. It is found that the pressure-induced phase transitions in the two enstatites are reversible, but with different transition pressures and transition behavior. An analysis of Raman spectra has revealed that the two enstatites have different high-pressure polymorphs. This result suggests that the space group of the high-pressure polymorph of orthoenstatite is not of C2/c, and that orthoenstatite and orthoferrosilite have different transition routes at room temperature and high pressure. The compressional behavior of the high-PC2/c enstatite is also discussed according to the pressure dependences of Raman frequencies. 相似文献
75.
由于腔模与激子对压力的依赖关系不同,所以可以选择不同的压力使激子和光场处于不同的耦合状态,从而实现对耦合的调谐。利用这种办法,我们观测到了代表激子与光场强耦合作用的Rabi分裂。由于在我们现有样品结构中压力对激子本征行为的影响很小,与以前报道的温度、电场等调谐方式相比,这种调谐方法不仅可以有效地调谐半导体微腔内激子与腔模的耦合程度,而且能够保持激子的本征性质在整个调谐过程中基本不变。这有助于研究在强耦合过程中激子极化激元的本征性质。将实验结果与压力下激子与腔模耦合理论进行拟合,得出了正确的Rabi分裂值。 相似文献
76.
77.
This paper describes a new capacitive structure of pressure sensor to increase simultaneously the sensitivity and the linearity of the transducer. This structure contains two capacitors which change in response to pressure, but in opposite senses. To increase even more the sensitivity of each capacitor, the pressure sensitive diaphragm carries a central boss. The optimal position and the length of the boss are also calculated. To cite this article: A. Ettouhami et al., C. R. Mecanique 332 (2004). 相似文献
78.
Summary The potential of liquid chromatography-mass spectrometry (LC-MS) has been studied for the simultaneous determination of sixteen carbamate and organophosphorus pesticides in honeybees using a traditional sample preparation protocol based on acetone extraction and dichloromethane partitioning. The performances of both atmospheric pressure chemical ionization (APCI) and electrospray (ES) interfaces were compared. APCI offered better sensitivity and specificity for a higher range of pesticides. Limits of quantification were from 0.01 to 0.17 mg kg–1, at which recoveries obtained were between 64 and 93%, except for pirimicarb that was at 13%, with relative standard deviations ranging from 7 to 20%. Fenitrothion, fenoxycarb, methiocarb and phoxim were found in bees from Valencian Community beehives at concentrations between 0.03 and 3.75 mg kg–1. 相似文献
79.
80.
本文用超声相比较方法测定了高Tc超导体La1.85Sr0.15CuO4,La2CuO4和YBa2Cu3O7的纵波和横波声速,进而导出了它们的纵向模量、切变模量、杨氏模量、泊松比、德拜温度及定体比热。在La1.85Sr0.15CuO4样品上,还进行了压力实验,发现所有弹性模量都是随压强增加而增加。定体比热cV和泊松比σ在高压下则略有下降。德拜温度是随压强增加而增加的。 相似文献