Si衬底上横向外延GaN材料的微结构和光学性质的研究

用氢化物气相外延 (HVPE)方法在Si(III)衬底上成功横向外延生长出晶体质量较好的GaN薄膜材料。透射电子显微镜 (TEM )的研究结果表明 ,横向外延区域GaN的位错密度明显减小。由于SiO2 掩膜腐蚀角的不同 (分别为 90°和 6 6°) ,导致了横向外延GaN材料一些独特的微观形貌。微区拉曼光谱由数百条拉曼散射曲线组成 ,每一条曲线有三个振动模 ,分别对应Si振动模式 (5 2 0cm- 1) ,E2 模式 (5 6 6cm- 1)和E1(LO)模式(732cm- 1)。在垂直条纹方向 ,峰位和峰宽没有明显的变化 ,而峰强约 5 μm会发生周期性变化     

Localized audio watermarking technique robust against time-scale modification

Synchronization attacks like random cropping and time-scale modification are very challenging problems to audio watermarking techniques. To combat these attacks, a novel content-dependent localized robust audio watermarking scheme is proposed. The basic idea is to first select steady high-energy local regions that represent music edges like note attacks, transitions or drum sounds by using different methods, then embed the watermark in these regions. Such regions are of great importance to the understanding of music and will not be changed much for maintaining high auditory quality. In this way, the embedded watermark has the potential to escape all kinds of distortions. Experimental results show strong robustness against common audio signal processing, time-domain synchronization attacks, and most distortions introduced in Stirmark for Audio.     

高压水射流粉碎原盐

高压水射流粉碎技术是近年发展起来的一项新型粉碎技术。文中介绍了水射流粉碎机理和新研制的后混合靶式水射流粉碎装置 ,并通过原盐粉碎实验证明 ,水射流粉碎具有效率高、工艺简单、产品粒度可调等特点 ,是一项具有良好发展前景的粉碎技术。     

全密封变压器用波纹油箱的波纹高计算

介绍了全密封变压器所用的液纹油相的波纹筋高的计算方法，并用试验进行了验证。     

酒泉盆地青西油田快速钻井技术

酒泉盆地青西地区油层储藏深 ,地层可钻性差 ,钻井过程中存在机械钻速低、井斜不易控制、刺断钻具频繁等问题。为此 ,在近年的钻井实践中 ,采取了优化钻具组合、优选钻头、应用 PDC钻头、强化钻具管理等措施 ,使该区块的钻井速度不断提高 ,钻井周期缩短 ,钻头用量减少 ,从而形成了一套适合该区块的快速钻井技术。     

自干扰抵消盲空时DS-CDMA信号检测技术

针对传统单用户检测器存在远近效应和性能下界问题,近年来提出的一系列最大SINR准则盲空时RAKE接收机,可以较好地合并期望用户的多径分量,同时抑制多址干扰用户能量.本文对这类接收机进行了进一步的研究,提出了一种自干扰抵消方法,更有效地克服了单用户检测器存在的性能下界以及远近效应问题.仿真结果验证了本文方法的有效性.     

In—situ Composite Based on Poly （ethylene terephthalate）,Polyamide and Polyethylene with Microfibres Formed through Extrusion and Hot Stretching

In-situ composites based on dispersed poly (ethylene terephthalate) (PET) or polyamide (PA),and continuous Polyethylene (PE) were prepared through a single screw extruder of Haake rheometer system with a rod-die relatively small in diameter.The extrudate was drawn at a drawing ratio of 3.1,and then quickly cooled in cold water.The specimens were obtained by injection molding at processing temperatures less than 190℃，far below the melting temperature of PET (265℃) and PA (230℃),which can maintain the solid state of PET and PA microfiber phase in the composites.Morphological observation with scanning electron microscopy (SEM) indicated that PET and PA can more or less form in-situ microfibers at compositions studied (0-20 wt pct PET or PA),and especially,PET and PA were almost deformed into fibers at the concentration of 15wt pct.Eensile strength and especially.PET and PA were almost deformed into fibers at the concentration of 15wt pct.Tensile strength and modulus of the blends reinforced by PET or PA microfibers showed to be increased from the tensile test results.The most noticeable improvement of the tensile properties occurred at 15wt pct of PET in PET/PE system,corresponding to the highest microfiber content,where the tensile strength reached 32.5 MPa,whereas only 19.5 MPa for the pure PE.     

国有股减持、政府隐性担保与投资者行为

国有股减持导致股票市场的大幅下跌，其咎不在以市场价减持国有股的减持方案．政府对股票市场的隐性担保造成投资者对市场走势的某种“理性的”稳定预期和信念．在此基础之上，政府和投资者塑造各自的心理和行为模式、国有股减持的信号含义就是政府要解除对市场的隐性担保．这个信号引发投资者固有的预期模式和行为模式的转变以及股票市场的信心危机。进而导致股票市场的“非理性反应”—市场以大幅下跌拒绝政府国有股减持和解除担保关系的行为、政府被迫停止国有股减持行为，但停止国有股减持并没有阻止股市的持续下跌，因为减持虽然停止，自减持发出的解除隐性担保的信号仍然有效。     

混合集成型光学拾音器的设计与制作

通过混合集成型结构光学拾音器的光学设计和芯片设计，制作了包含微光学棱镜，光电探测器和信号放大电路的混合集成型光学拾音器。经过测试，发现有较好的信号输出特性，表明混合集成型光学拾音器已基本研制成功。