Zn diffusion of In0.5Ga0.5P investigated by photoluminescence measurements

Zn diffusion of an In_0.5Ga_0.5P layer grown on semi-insulating GaAs substrate by the liquid phase epitaxy technique has been investigated using photoluminescence (PL) measurements. The PL spectrum shows a characteristic emission peak of In_0.5Ga_0.5P at 1.934 eV after diffusion. From temperature-dependent studies of this peak and depth profiling of this luminescence, it was found that this peak behaves like D-A (donor-acceptor) pair recombination and is associated with the interstitial Zn donor to substitutional Zn acceptor band transition. Also it was found that recombination due to interstitial Zn donor is dominant near the surface and decreases with increasing depth. The calculated activation energy of substitutional acceptor was found to be 47 meV.     

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川东高陡构造由于层速度在横向上的剧变，通常的时问偏移处理不能使反射正确归位，得不到正确的构追形态和高点位置。文章针对川东陡构造的地质及地球物理特征，对时间偏移，Geodepth软件叠前和叠后波动方程深度偏移，以及叠后射线变速深度偏移等方法做适用性研究后发现：对于川东这种地表高差大、地腹构追形态复杂导致层速度变化剧烈的地区，深度偏移明显比时间偏移校正能力强，所得到的构造形态和高点位置更准确，并且在速度校正方面叠前比叠后深度偏移好。但是，叠前与叠后深度偏移在成像上相当，在运算速度上后者比前者快10倍。由此，总结出了适合川东高陡构造深度偏移的方法及一套叠前、叠后深度偏移处理流程。通过对温泉井、沙坪场、黄泥堂、南门场等构造的实际应用，获得了良好的钻探符合率及钻探成功率，这表明深度偏移具有明显效果。对于高陡复杂构造的偏移处理具有参考价值。     

Dielectric reference coatings for the evaluation of thin film characterization techniques

Thin film technology has an increasing demand for industrial reliable characterization techniques. A precise absolute determination of layer thickness, interface width and the quantification of depth profiles in dependence on resolution limits of the measurement are required. Certified reference materials, certified reference coatings (CRCs) and non-destructive evaluation techniques can meet these requirements. Dielectric reference coatings (SiO₂, Si₃N₄) were used for metallographic preparation (e.g. bevelled cross-sections), optical characterization techniques (e.g. spectroscopic ellipsometry (SE)), and films of SiO₂, Si₃N₄ and Al₂O₃ were applied to reference measurements in depth profiling of layer stacks (e.g. radio frequency glow discharge optical emission spectroscopy). Thickness and refractive index of these dielectric single-and multilayer coatings on different substrate materials are accurately determined in advance by means of SE. These values are subsequently used for precise angle determination of bevelled cross-sections, for reference and re-calibration purposes in thin film characterization (system reproducibility) and in surface analysis (determination of sputter and erosion rates, depth profiles). Examples are discussed for different applications and the calculated data are compared with experimental results. It is shown that reproducible commercial coatings are also of importance for use as CRCs.     

用~(19)F(p,αγ)共振核反应测深度分布非共振产额的影响

用~(19)F(p,αγ)共振核反应测量浓度深度分布是一个应用广泛的方法,发表了大量的文章。因为出射的α粒子能量低,不容易探测,所以几乎无例外的都是测γ射线。其中不少文章认为,测得的样品激发函数与靶核浓度深度分布形状是非常相似的,二者之间只差一个比例因子。实际上,这只在薄靶情况下是对的,对于厚靶,二者并不相似。     

Experiments on the thermal stratification in the branch of NPP

The thermal stratification phenomena, frequently occurring in the component of nuclear power plant system such as pressurizer surge line, steam generator inlet nozzle, safety injection system (SIS), and chemical and volume control system (CVCS), can cause through-wall cracks, thermal fatigue, unexpected piping displacement and dislocation, and pipe support damage. The phenomenon is one of the unaccounted load in the design stage. However, the load have been found to be serious as nuclear power plant operation experience accumulates. In particular, the thermal stratification by the turbulent penetration or valve leak in the SIS and SCS pipe line can lead these safety systems to failure by the thermal fatigue. Therefore in this study an l/lO scaledowned experimental rig had been designed and installed. And a series of experimental works had been executed to measure the temperature distribution (thermal stratification) in these systems by the turbulent penetration, valve leak, and heat transfer through valve. The results provide very valuable informations such as turbulent penetration depth, the possibility of thermal stratification by the heat transfer through valve, etc. Also the results are expected to be useful to understand the thermal stratification in these systems, establish the thermal stratification criteria and validate the calculation results by CFD Codes such as Fluent, Phenix, CFX.     

终端保护开关在斜井提升机中的应用

矿井提升机为保证安全运行均装没有提升过卷保护装置，一般过卷保护工作原理为：深度指示器在提升过程中指示提升容器的位置，在容器接近终端位置时发出减速信号，在提升过卷时，切断安全回路，进行安全制动。     

宁德滩涂软土工程特性研究

宁德海域分布深厚淤泥。通过多种勘探手段对宁德滩涂淤泥的研究,查明了该地层的岩土工程特性,探寻了测取其各种地质参数的最佳试验方法和组合,通过对力学参数与深度的规律性研究,总结了采用静力触探推算宁德滩涂淤泥不排水抗剪强度的经验公式,验证了原位测试手段在查找岩土规律性方面的优势,对今后宁德海积软土区域的综合勘探和工程建设有指导意义。     

Adaptive depth truncation filter for MVC based compressed depth image

In multiview video plus depth (MVD) format, virtual views are generated from decoded texture videos with corresponding decoded depth images through depth image based rendering (DIBR). 3DV-ATM is a reference model for the H.264/AVC based multiview video coding (MVC) and aims at achieving high coding efficiency for 3D video in MVD format. Depth images are first downsampled then coded by 3DV-ATM. However, sharp object boundary characteristic of depth images does not well match with the transform coding based nature of H.264/AVC in 3DV-ATM. Depth boundaries are often blurred with ringing artifacts in the decoded depth images that result in noticeable artifacts in synthesized virtual views. This paper presents a low complexity adaptive depth truncation filter to recover the sharp object boundaries of the depth images using adaptive block repositioning and expansion for increasing the depth values refinement accuracy. This new approach is very efficient and can avoid false depth boundary refinement when block boundaries lie around the depth edge regions and ensure sufficient information within the processing block for depth layers classification. Experimental results demonstrate that the sharp depth edges can be recovered using the proposed filter and boundary artifacts in the synthesized views can be removed. The proposed method can provide improvement up to 3.25 dB in the depth map enhancement and bitrate reduction of 3.06% in the synthesized views.     

深度图实时提取系统中后处理的设计与实现

基于硬件的深度图实时提取系统可实现深度图的实时提取,但由于硬件结构的局限性不能像软件那样实现较复杂的匹配算法,会产生较多误匹配。在深度图实时提取系统上设计和实现深度图后处理功能,先对视差结果进行匹配唯一性检测,再根据需要针对左右视图对应的视差结果分别设计两种左右一致性检测方案,最后利用正确的深度值进行空洞填充。实验表明该设计和实现的后处理功能可与深度图的提取在同一系统上实时地进行,并能得到质量较好的深度图。     

An amplitude-preserved adaptive focused beam seismic migration method

Gaussian beam migration (GBM) is an effective and robust depth seismic imaging method, which overcomes the disadvantage of Kirchhoff migration in imaging multiple arrivals and has no steep-dip limitation of one-way wave equation migration. However, its imaging quality depends on the initial beam parameters, which can make the beam width increase and wave-front spread with the propagation of the central ray, resulting in poor migration accuracy at depth, especially for exploration areas with complex geological structures. To address this problem, we present an adaptive focused beam method for shot-domain prestack depth migration. Using the information of the input smooth velocity field, we first derive an adaptive focused parameter, which makes a seismic beam focused along the whole central ray to enhance the wavefield construction accuracy in both the shallow and deep regions. Then we introduce this parameter into the GBM, which not only improves imaging quality of deep reflectors but also makes the shallow small-scale geological structures well-defined. As well, using the amplitude-preserved extrapolation operator and deconvolution imaging condition, the concept of amplitude-preserved imaging has been included in our method. Typical numerical examples and the field data processing results demonstrate the validity and adaptability of our method.