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971.
高强IF钢析出物的析出特征   总被引:3,自引:0,他引:3  
王作成  朱学刚 《钢铁》1995,30(2):63-68
高强IF钢是汽车用深冲钢板中深冲性能最好的高强度钢板。目前,国际上对该钢种的研究十分活跃。本文在实验条件下,通过对高强IF钢析出物的观察研究了高强IF钢析出物的析出特征,发现了新的析出相TiFeP,并对磷对深冲性能影响的作用机制,进行了探讨。  相似文献   
972.
无间隙原子钢的微观结构特征和塑性应变比   总被引:1,自引:0,他引:1  
何崇智  温熙宇 《钢铁》1995,30(3):53-57
采用X射线衍射的ODF和LP分析技术,SEM电子通道花样和蚀坑技术观测,研究了超深冲无间隙原子钢板的微观结构特征。结果表明:控制化学成分、保证基体纯净、优选工艺参数,促进强的γ-〈111〉∥N.D纤维织构的形成是获得优异成型性的关键。用CMTP方法,由ODF织构数据从理论计算了塑性应变比(r),表明rm值高达3.18。文中讨论了再结晶织构形成机制。  相似文献   
973.
详细介绍了一种新颖、快速响应的金属-绝缘层-半导体构成的MIS型单晶硅液晶光阀的结构、工作机理、制作工艺和性能参数测试。液晶采用45°扭曲向列型混合场效应工作模式。所得到的光阀的极限分辨率为40lp/mm,口径40mm,最大对比度>100:1,在930nm(△λ=40nm)写入光灵敏度为20μW/cm2,响应时间为15ms。报道了该光阀在大屏幕投影显示中的应用。  相似文献   
974.
A multiresolution analysis of digital gray-level images is presented. A gray-level multi-scale framework is determined from two main assumptions: the gray scale is binary at the finest spatial resolution, and the gray levels of composed regions are obtained additively. In order to interrelate the gray-level histograms of the same image at different resolutions, probabilistic linear models are developed, which are then applied for estimation. Linear-optimization theory is used as a way of constructing such models. A general procedure for image processing is sketched, based on gray-level estimation. A versatile algorithm for nonlinear filtering is derived. Some examples of prospective applications are given.This work was partially supported by grant TIC91-646 from the DGYCIT of the Spanish Government.  相似文献   
975.
The growth of nominally undoped GaSb layers by atmospheric pressure metalorganic vapor phase epitaxy on GaSb and GaAs substrates is studied. Trimethylgallium and trimethylantimony are used as precursors for the growth at 600°C in a horizontal reactor. The effect of carrier gas flow, V/III-ratio, and trimethylgallium partial pressure on surface morphology, electrical properties and photoluminescence is investigated. The optimum values for the growth parameters are established. The carrier gas flow is shown to have a significant effect on the surface morphology. The optimum growth rate is found to be 3–8 μm/ h, which is higher than previously reported. The 2.5 μm thick GaSb layers on GaAs are p-type, having at optimized growth conditions room-temperature hole mobility and hole concentration of 800 cm2 V−1 s−1 and 3·1016 cm-3, respectively. The homoepitaxial GaSb layer grown with the same parameters has mirror-like surface and the photoluminescence spectrum is dominated by strong excitonic lines.  相似文献   
976.
用于X光激光实验的反射式线聚焦光学系统的设计和分析   总被引:1,自引:1,他引:0  
冯国英  吕百达 《激光技术》1995,19(3):164-170
基于三维光线追迹的象差计算,对卢瑟福实验室用离轴球面反射线聚焦系统作了分析。然后,首次提出了用于X光激光实验的两类新的反射式线聚焦构型,即反射式光楔列阵和光锥列阵系统,并作了计算。最后,对所得结果作了比较和讨论。  相似文献   
977.
Epitaxial CdTe layers were grown using organometallic vapor phase epitaxy on Si substrates with a Ge buffer layer. Ge layer was grown in the same reactor using germane gas and the reaction of germane gas with the native Si surface is studied in detail at low temperature. It is shown that germane gas can be used to “clean” the Si surface oxide prior to CdTe growth by first reducing the thin native oxide that may be present on Si. When Ge layer was grown on Si using germane gas, an induction period was observed before the continuous layer of Ge growth starts. This induction period is a function of the thickness of the native oxide present on Si and possible reasons for this behavior are outlined. Secondary ion mass spectrometry (SIMS) data show negligible outdiffusion and cross contamination of Ge in CdTe.  相似文献   
978.
铯原子激光共振电离   总被引:1,自引:0,他引:1  
用Nd:YAG及其泵浦的染料激光进行铯原子三步共振电离。求解了非饱和共振过程速率方程,计算出基态和激发态共振吸收截面,给出电离效率分别与激发电离速率以及作用时间的变化关系,得到饱和激发电离的流量条件和通量条件。  相似文献   
979.
GalnSb alloys as well as the constituent binaries InSb and GaSb have been grown by organometallic vapor phase epitaxy using the new antimony precursor trisdimethylaminoantimony (TDMASb) combined with conventional group III precursors trimethylindium (TMIn) and trimethylgallium (TMGa). InSb layers were grown at temperatures between 275 and 425°C. The low values of V/III ratio required to obtain good morphologies at the lowest temperatures indicate that the pyrolysis temperature is low for TDMASb. In fact, at the lowest temperatures, the InSb growth efficiency is higher than for other antimony precursors, indicating the TDMASb pyrolysis products assist with TMIn pyrolysis. A similar, but less pronounced trend is observed for GaSb growth at temperatures of less than 500°C. No excess carbon contamination is observed for either the InSb or GaSb layers. Ga1-xInxSb layers with excellent morphologies with values of x between 0 and 0.5 were grown on GaSb substrates without the use of graded layers. The growth temperature was 525°C and the values of V/III ratio, optimized for each value of x, ranged between 1.25 and 1.38. Strong photoluminescence (PL) was observed for values of x of less than 0.3, with values of halfwidth ranging from 13 to 16 meV, somewhat smaller than previous reports for layers grown using conventional precursors without the use of graded layers at the interface. The PL intensity was observed to decrease significantly for higher values of x. The PL peak energies were found to track the band gap energy; thus, the luminescence is due to band edge processes. The layers were all p-type with carrier concentrations of approximately 1017 cm3. Transmission electron diffraction studies indicate that the Ga0.5In0.5 Sb layers are ordered. Two variants of the Cu-Pt structure are observed with nearly the same diffracted intensities. This is the first report of ordering in GalnSb alloys.  相似文献   
980.
GaP:(N)的背景光谱和发光尖峰   总被引:1,自引:0,他引:1  
获得高分辨GaP(N)光致发光光谱,观察到等电子陷陆束缚激子发光中LO和loc多声子发射,其强度分布答合泊松分布。将声子伴带区分为直接光跃迁和间接光跃迁,并进行了相应讨论,还观察到局域声子效应--光谱相似定律和相当显著的背景光谱。  相似文献   
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