微拉曼光谱法检测非制冷红外焦平面阵列残余应力

实验所采用的非制冷红外焦平面阵列由Si O2薄膜和硅基底组成,具有MEMS微结构。热氧化生成Si O2薄膜过程中会因热失配和晶格失配而产生很大的残余应力,其大小影响微元件的整个性能,对其检测至关重要。利用微拉曼光谱法对两个Si O2薄膜/硅基微结构的进行了残余应力检测。实验结果表明,硅层横截面上残余应力随着深度的增大而递减,近似成二次曲线分布,并结合力平衡概念和微积分方法,计算出两个试样的薄膜残余应力大小分别为3.3 GPa和2.2 GPa。对薄膜微小单元体进行应力分析,得出薄膜残余应力为压应力。在应力释放过程中,达到GPa量级的残余应力会使薄膜皱曲、弯曲,产生鼓峰,甚至会造成膜层的破坏失效。     

企业货币资金内部控制的重点与方法

以西南油气田分公司为例探讨企业货币资金内部控制的重点和方法。认为:货币资金内部控制,其重点就是实行收支两条线的集中管理方法,即把住收入源,控制支出关,管好“四个点”。企业货币资金内部控制的方法主要有3种,即不相容职务相分离控制、授权批准制度和货币资金收支两条线管理方法。     

Secondary radiation in transmission-type X-ray tubes: Simulation, practical issues and solution in the context of X-ray microtomography

In laboratory-based X-ray radiography and computed tomography, the X-rays are assumed to originate from one single focal spot with a finite spot size, which is generated by focussing accelerated electrons on the target material. However, apart from this focal spot, X-rays can also be produced elsewhere in the tube system. A major contribution of this parasitic radiation originates from electrons that are backscattered from the target material, into the X-ray tube system, where they can produce so-called off-focus or secondary X-rays. This phenomenon has been widely studied for rotating anode X-ray tubes in medical imaging systems, but not for transmission-type microfocus X-ray tubes. This paper presents a study on the origin of secondary radiation in this kind of X-ray tubes, which is performed by Monte Carlo simulations and by experimental measurements. The impact of this phenomenon on the imaging process is studied, and two correction methods are proposed, both on the hardware and on the software levels.     

应用Talbot效应和莫尔技术测量长焦距

给出测量透镜长焦距的一个方法，该方法的原理是Ｔａｌｂｏｔ干涉。在测量中，根据莫尔条纹的斜角确定正、负透镜的焦距。方法简单，灵敏度可调。     

非制冷红外焦平面CMOS读出电路设计

在过去的10年里红外焦平面阵列成像技术逐渐进入了成熟期,从红外焦平面的发展背景出发,简要介绍了一种新颖的非制冷焦平面成像技术,论述了读出电路在红外焦平面信号传输中的作用并介绍了其基本框图,分析了国内外焦平面读出电路的现状,最后提出了一些在红外焦平面阵列读出电路设计中所需要注意的问题。     

球面波通过透镜-光阑分离系统的焦移

用Collins公式研究了均匀球面波通过透镜-光阑分离系统的轴上光强分布。经推导得出焦移解析表达式。在这类光学系统中,光束的焦移可能大于,等于或小于零。分析表明,焦移的大小与菲涅尔数、透镜-光阑的分离程度以及入射波波面曲率半径等因素有关,并得出了消除焦移的条件。     

感光材料分辨力测定实验研究

使用ＰＩ－Ｃ感光材料分辨力测定仪,测定了感光材料分辨力。测定试验不仅证明感光材料分辨力测定仪器操作稳定可靠、重复性好,而且测定实验加深了对感光材料的感光影象特性的研究。实验表明,最佳焦面实际集中在各种胶片乳剂层表层。     

Colour names and focal colours on electronic displays

This study identified the colours that were perceived as being the best examples (focal colours) of 10 common colour names when viewed on an electronic display. A total of 204 colours derived from a reflective surface colour measurement system (Munsell) were converted to the Commission Internationale de l'Eclairage (CIE) 1976 system and presented on a cathode ray tube (CRT). Forty subjects chose what was perceived as the best examples for each of the following colour terms: purple, blue, aqua, green, yellow, orange, red, pink, grey, and white. Results show that focal colours on a CRT do not always correspond to the typical colours used or to the best examples for reflective surface colours. The display designer should consider these differences when selecting colours for a display.     

Software for slip-tendency analysis in 3D: A plug-in for Coulomb

Slip-tendency analysis is a valuable tool in fault reactivation evaluation and seismic hazard assessment as it provides a means of quantifying the slip potential on mapped or suspected faults in a known or inferred stress field. We developed an interactive graphic tool to perform slip-tendency analysis. The application is written in MATLAB in the form of plug-ins for COULOMB, a graphic-rich deformation and stress change open-source software. In addition to identifying the faults most prone to reactivation, we compute and plot synthetic focal mechanisms from the direction and sense of likely slip. This allows compatibility between focal mechanisms and geological structures to be verified. Both individual faults and fault networks can be considered in three dimensions. The potential for slip depends on the prevailing stress field, the fault surface orientation and the coefficient of friction. These parameters are given interactively in a Windows environment. The application thus offers an easy-to-use graphical interface with the possibility of fast parameter modification and 3D visualization of the results.     

Optimization of scale and parametrization for terrain segmentation: An application to soil-landscape modeling

This paper presents a procedure to optimize parametrization and scale for terrain-based environmental modeling. The workflow was exemplified on crop yield data, which is assumed to represent a proxy for soil productivity. Focal mean statistics were used to generate different scale levels of terrain derivatives by increasing the neighborhood size in calculation. The degree of association between each terrain derivative and crop yield values was established iteratively for all scale levels through correlation analysis. The first peak of correlation indicated the scale level to be further retained. To select the best combination of terrain parameters that explains the variation of crop yield, we ran stepwise multiple regressions with appropriately scaled terrain parameters as independent variables. These techniques proved that the mean curvature, filtered over a neighborhood of 55 m, together with slope, made up the optimal combination to account for patterns of soil productivity.To illustrate the importance of scale, we compared the regression results of unfiltered and filtered mean curvature vs. crop yield. The comparison shows an improvement of R² from a value of 0.01 when the curvature was not filtered, to 0.16 when the curvature was filtered within 55×55 m neighborhood size.The results were further used in an object-based image analysis environment to create terrain objects containing aggregated values of both terrain derivatives and crop yield. Hence, we introduce terrain segmentation as an alternative method for generating scale levels in terrain-based environmental modeling, besides existing per-cell methods. At the level of segments, R² improved up to a value of 0.47.