Effective improvement of high-k Hf-silicate/silicon interface with thermal nitridation

The electrical properties of polysilicon gate MOS capacitors with hafnium silicate (HfSiO) dielectric, with and without NH/sub 3/ nitridation, were investigated. The results show that with NH/sub 3/ nitridation prior to deposition of HfSiO can effectively tune the flatband voltage close to that of conventional oxide and significantly improve the leakage properties over SiO/sub 2/ (three orders reduction). Furthermore, the excellent interface quality has been evidenced by the result of immunity against soft breakdown with NH/sub 3/ nitridation.     

基于动态贝叶斯网络的手势识别

研究了动态手势的识别技术,实现人机交互。采用HSV空间的肤色模型实现手势定位,光流场算法进行手势追踪,具有较好的快速性、准确性和鲁棒性。提出应用链码描述手势运动矢量,双手相对位置标量以及双手与脸的相对位置标量,将多条链码作为动态手势的特征进行提取。建立了一个动态手势识别的动态贝叶斯网络模型,将一部分手势链码作为训练样本,通过对DBNs的推理学习实现手势识别。实验构建动态手势识别系统,可应用于多媒体、智能电器或幻灯片控制之中。     

Diamond K-250射频气体激光调制器的设计

采用TL494、SN75172等元件组成了Diamond K-250射频气体激光调制器，调制频率、占空比和调制度单儿可调。分析了电路的工作原理，给出了调制频率，占空比所对应的激光输出功率曲线。     

基于GPRS的服务质量(QOS)控制

在GPRS协议体系中,不仅定义了高层的分组数据传输协议,它也尝试提供对数据流的服务质量保证。GPRS定义了一些系列的QOS参数和服务等级,但是没有对QOS控制和过程进行详细描述。在这篇论文中,将讨论多种QOS服务保证机制,它们包括:接入控制、资源预留、整形和队列管理。按照它们对应的GPRS网络的组件和协议等级的不同,分别对他们进行详细的描述。     

信息社会的理念与发展

首先介绍了信息社会的基本特征，并围绕信息的接入、信息的发布、知识产权、隐私权、信息安全和文化多元性等阐述了信息伦理的内容和概念。最后介绍了信息对人类生活的影响，主要包括交往方式、信息处理方式、学习方式、商业运作方式、医疗方式、产品设计方式、科研方式和政府工作方式等。     

Pd-Ru/C催化剂的制备及其甲酸氧化活性研究

利用微波辅助有机溶胶法成功制备了Pd3Ru/C纳米电催化剂。相比传统的高压有机溶胶法,该法大大降低了有机溶剂的使用量并缩减了反应时间,是一种环境友好和资源节约的新型方法。采用XRD,TEM,XPS和电化学测试等手段对其结构和电化学性能进行了表征和评价。XRD和TEM结果表明微波辅助制备的Pd3Ru/C催化剂其粒径只有约3.0 nm,分散性也较Pd/C得到显著改善;XPS谱图证实催化剂活性组分Pd和Ru的原子比约为3.13∶1,Pd和Ru两种元素间发生了相互作用。与同条件制备的Pd/C催化剂相比,Pd3Ru/C催化剂在电极上发生甲酸氧化反应的主要峰电位负移了约100 mV,峰电流密度增大了2/3左右,其甲酸电氧化活性得到明显提高。     

垂直腔面发射激光器的TO封装工艺操作误差分析

采用FRESNEL光学软件和MATLAB编程,详细分析了垂直腔面发射激光器的TO封装工艺操作误差对耦合效率的影响.发现在芯片横向偏移、芯片倾斜和管帽倾斜这三种操作误差中,管帽倾斜对封装组件的耦合效率影响最大.     

Optimal Block Design for Asynchronous Wake-Up Schedules and Its Applications in Multihop Wireless Networks

In this paper, we consider the problem of designing optimal asynchronous wake-up schedules to facilitate distributed power management and neighbor discovery in multihop wireless networks. We first formulate it as a block design problem and derive the fundamental trade-offs between wake-up latency and the average duty cycle of a node. After the theoretical foundation is laid, we then devise a neighbor discovery and schedule bookkeeping protocol that can operate on the optimal wake-up schedule derived. To demonstrate the usefulness of asynchronous wake-up, we investigate the efficiency of neighbor discovery and the application of on-demand power management, which overlays a desirable communication schedule over the wake-up schedule mandated by the asynchronous wake-up mechanism. Simulation studies demonstrate that the proposed asynchronous wake-up protocol has short discovery time which scales with the density of the network; it can accommodate various traffic characteristics and loads to achieve an energy savings that can be as high as 70 percent, while the packet delivery ratio is comparable to that without power management.     

掺杂室沉积本征微晶硅材料及其在太阳能电池中的应用

在掺杂P室采用甚高频等离子体增强化学气相沉积（VHF—PECVD）技术,制备了不同硅烷浓度条件下的本征微晶硅薄膜．对薄膜电学特性和结构特性的测试结果分析表明：随硅烷浓度的增加,材料的光敏性先略微降低后提高,而晶化率的变化趋势与之相反;X射线衍射（xRD）测试表明材料具有（220）择优晶向．在P腔室中用VHF—PECVD方法制备单结微晶硅太阳能电池的i层和p层,其光电转换效率为4．7％,非晶硅／微晶硅叠层电池（底电池的p层和i层在P室沉积）的效率达8．5％．     

Authentic delay bounded event detection in heterogeneous wireless sensor networks

When using wireless sensor networks for real-time event alarming, it is critical to ensure event notification in a timely manner. Additionally, it is extremely important to ensure the alarms generated by the sensors propagate securely through the network to the sink. Another important factor to consider is energy, as it is a limited resource in wireless sensor networks. Accordingly, maximizing network lifetime is always an optimization goal. To address the aforementioned concerns, in this paper we present the Authentic Delay Bounded Event Detection System (ADBEDS). ADBEDS works in rounds, and in each round an event detection tree is responsible for simultaneously detecting events, routing packets to a gateway node, and detecting injection of false packets. The ADBEDS can support k-watching composite events to allow event detection in a redundant manner. Additionally, the corresponding event alarm can be delivered within a user-specified bounded delay. The use of energy-based keying allows smaller, more efficient keys as input to security mechanisms, allowing further reduction in energy consumption of the ADBEDS. We evaluate the energy efficiency and reliability of ADBEDS using theoretical analysis and simulation.