Determining the Instantaneous Effective Energy of x-Ray Tube Bremsstrahlung

A method is described for determining the instantaneous effective energy of x-ray tube brehmsstrahlung by means of two semiconductor detectors employing epitaxial GaAs structures and a measurement circuit, which together determine the effective energy with an error of 5% in the range 20–80 keV in the presence of nonlinearity in the detector response.     

阜阳地区石炭-二叠系煤系烃源岩特征

阜阳地区石炭-二叠系煤系地层发育，但由于勘探程度较低，对该区煤系地层烃源岩的生烃潜力认识不清，严重制约了该区的油气勘探。在已有资料的基础上，通过有机地球化学和有机岩石学方法并结合模拟实验，探讨了该区煤系烃源岩的生烃潜力。研究结果表明阜阳地区石炭-二叠系煤系烃源岩有机质丰度达到中等-好烃源岩标准，有机质类型以腐殖型为主，盆地模拟结果显示阜阳地区石炭-二叠系煤系地层油资源量为（30.47~152.33）×10⁶t，气资源量为（266.7～1333.7）×10⁸m³，展示阜阳地区石炭-二叠系煤系地层具有较好的生油气潜力。     

半导体量子点中极化子的有效质量

研究了半导体量子点中极化子的有效质量.采用改进的线性组合算符方法,导出在电子-体纵光学声子(LO)强耦合时抛物量子点中极化子的振动频率、相互作用能和有效质量随受限强度和电子-声子耦合强度的变化.对RbCl晶体量子点进行了数值计算,结果表明,量子点受限越强,半导体量子点中强耦合极化子的振动频率和有效质量就越大;极化子的相互作用能随受限强度的增加先急剧增加,当达到极值后,随受限强度的增加而急剧减少     

WPAN/WLAN应用环境下基于PER的链路自适应算法

本文重点研究基于包错误率测量的链路自适应算法，分析了包错误率与信道参数的关系，提出了一种有别于固定门限值方案的优化门限值方案。仿真结果表明，优化门限值方案的网络吞吐量要大于固定门限值方案和基于信干比估计的链路自适应算法，最大增幅可达12Mbit/s。在系统引入重传机制后，网络吞吐量将有所损失，但最大不超过1Mbit/s，相比较服务质量的提高是值得的。需指出的是，虽然分析和仿真均以HIPERLAN／2为例，但不失一般性，它们同样适合于WPAN/WLAN等类似系统。     

区域分割法辅助计算复杂图像面积

介绍计算具有复杂边缘轮廓的图像面积的区域分割法。采用鼠标多边形作图法近似圈定待处理的图像区域。本文由格林定理出发得到有限连续边界与其包围区域面积之间的函数关系,并且应用这一函数关系得出多边形与其包围区域面积的数学关系,近似得到图像区域面积。文中以烟幕图像为例对上述结论进行了验证。文章最后给出了在VC++环境下实现多边形分割的部分源代码。     

Design Methodology and Area Sensitivity Analysis of Horizontal Subsurface Flow Constructed Wetlands

An approach is presented to satisfy the demand for simple criteria, guidelines and models for the preliminary sizing of horizontal subsurface flow (SF) constructed wetland systems. This approach eliminates time-consuming calculations and iterations by providing graphical solutions for wetland system sizing. Therefore, it can be used for the preliminary assessment of new or performance evaluation of existing subsurface flow constructed wetland systems. The validity of this methodology is checked with data from existing systems and is found to be quite satisfactory. This methodology is combined with simple equations predicting the maximum wetland capacity in summer, so as to assist designers in sizing installations in tourist areas with increased summer populations. Furthermore, based on this methodology, a sensitivity analysis is performed of the area requirements for wastewaters of various strengths and various design conditions and performance criteria. The results provide a useful overview to engineers and further simplify the design methodology of new subsurface flow constructed wetland systems.     

基于小波变换的不同融合规则的图像融合研究

图像融合是一种重要的增强图像信息的方法。提出了一种基于多尺度分解的像素图像融合方法。利用小波变换按照不同融合规则及融合算子构造融合图像对应的小波系数。通过对可见光图像与红外图像进行融合的实验比较表明，以像素的局部能量为准则的融合效果更好，既可避免传统融合规则的信息损失，又提高了融合图像的空间分辨率和清晰度，融合图像更符合人的视觉特性，也有利于机器视觉。     

塔里木盆地雅—轮地区断层封堵性研究

塔里木盆地雅—轮地区大部分圈闭及油气藏的形成与断裂作用密切相关,对断层封堵性的综合研究已成为该地区油气勘探的重要因素。应用地质定性分析、Allen剖面分析及断层涂抹量计算等方法,通过对研究区4个典型断层封堵油气藏的系统解剖研究,建立雅—轮地区断裂封堵性评价标准,对雅—轮地区断层的封堵性进行综合评价。雅—轮地区断层整体封堵效果良好,断层在圈闭形成和油气聚集过程中起着重要的控制作用,形成一系列沿断层带状分布的油气藏。亚南断裂的封堵效果东部要优于西部,下部要优于上部。轮台断裂在不同部位、不同深度均存在着不同的封堵性能,封堵非均质性明显,总体显示断裂东部地区(也根附近)的封堵性要好于西部雅南地区。      

Chemische Zusammensetzung und Mikrostruktur polymerabgeleiteter Gläser und Keramiken im System Si–C–O. Teil 2: Charakterisierung der Gefügeausbildung mittels hochauflösender Durchstrahlungselektronenmikroskopie und Feinbereichsbeugung

Chemical Composition and Microstructure of Polymer‐Derived Glasses and Ceramics in the Si–C–O System. Part 2: Characterization of microstructure formation by means of high‐resolution transmission electron microscopy and selected area diffraction Liquid or solid silicone resins represent the economically most interesting class of organic precursors for the pyrolytic production of glass and ceramics materials on silicon basis. As dense, dimensionally stable components can be cost‐effectively achieved by admixing reactive filler powders, chemical composition and microstructure development of the polymer‐derived residues must be exactly known during thermal decomposition. Thus, in the present work, glasses and ceramics produced by pyrolysis of the model precursor polymethylsiloxane at temperatures from 525 to 1550 °C are investigated. In part 1, by means of analytical electron microscopy, the bonding state of silicon was determined on a nanometre scale and the phase separation of the metastable Si–C–O matrix into SiO₂, C and SiC was proved. The in‐situ crystallization could be considerably accelerated by adding fine‐grained powder of inert fillers, such as Al₂O₃ or SiC, which permits effective process control. In part 2, the microstructure is characterized by high‐resolution transmission electron microscopy and selected area diffraction. Turbostratic carbon and cubic β‐SiC precipitate as crystallization products. Theses phases are embedded in an amorphous matrix. Inert fillers reduce the crystallization temperature by several hundred °C. In this case, the polymer‐derived Si–C–O material acts as a binding agent between the powder particles. Reaction layer formation does not occur. On the investigated pyrolysis conditions, no crystallization of SiO₂ was observed.     

无线局域网安全问题研究

为了提供相当于有线局域网的数据安全,IEEE802.11定义了有线等价保密(WEP)协议。然而,最近的研究发现WEP存在严重的缺陷。介绍了无线局域网存在的安全隐患,分析了WEP的结构以及WEP协议的缺陷以及可能遭受的攻击,并探讨了改进方案。