1.3 /spl mu/m InGaAsN vertical cavity surface emitting lasers grown by MOCVD

The first InGaAsN VCSELs grown by MOCVD with CW lasing wavelength longer than 1.3 /spl mu/m are reported. The devices were of conventional p-i-n structure with doped DBR mirrors. CW lasing up to 65/spl deg/C was observed, with a maximum output power at room temperature of 0.8 mW for multimode devices and nearly 0.3 mW for single-mode devices.     

基于飞艇的反舰导弹过靶实况空中摄录系统的方案设计

本设计在对摄录平台及任务设备研究分析的基础上,给出了以系留和有动力飞艇相结合实现反舰导弹过靶实况摄录系统的初步方案和可行性分析.分析表明,反舰导弹过靶实况空中摄录系统建设是提高靶场可视化水平的重要途径之一,对提高靶标综合保障能力有重要意义.     

基于三维地理信息系统技术的空爆冲击波对大规模城市建筑群毁伤效应模型研究

为了在三维地理信息系统中实现空爆核武器对城市建筑群毁伤效应的可视化,对核爆相关理论和已有经验公式进行了研究,归纳得出空爆炸冲击波对城市建筑物毁伤效应的数学模型;以地理信息系统技术为基础,以离散拟合思想为依据,提出了空爆冲击波对大规模城市建筑群毁伤效应的物理模型;提出利用四面体剖分模型对毁伤后的建筑物进行表达。文中提出的模型为空爆核武器对城市毁伤效应的科学可视化提供了技术支持。     

云计算数据库的测试技术研究与应用

介绍了基于云计算的数据库产品的架构,针对云计算数据库在电信企业业务类型负载下的表现,重点分析了云计算数据库的测试技术标准,详细阐述了云计算数据库处理能力的衡量和评估方法。     

An efficient approach for power delivery network design with closed-form expressions for parasitic interconnect inductances

Investigation of a dc power delivery network, consisting of a multilayer PCB using area fills for power and return, involves the distributed behavior of the power/ground planes and the parasitics associated with the lumped components mounted on it. Full-wave methods are often employed to study the power integrity problem. While full-wave methods can be accurate, they are time and memory consuming. The cavity model of a rectangular structure has previously been employed to efficiently analyze the simultaneous switching noise (SSN) in the power distribution network. However, a large number of modes in the cavity model are needed to accurately simulate the impedance associated with the vias, leading to computational inefficiency. A fast approach is detailed herein to accelerate calculation of the summation associated with the higher-order modes. Closed-form expressions for the parasitics associated with the interconnects of the decoupling capacitors are also introduced. Combining the fast calculation of the cavity models of regularly shaped planar circuits, a segmentation method, and closed-form expressions for the parasitics, an efficient approach is proposed herein to analyze an arbitrary shaped power distribution network. While it may take many hours for a full-wave method to do a single simulation, the proposed method can generally perform the simulation with good accuracy in several minutes. Another advantage of the proposed method is that a SPICE equivalent circuit of the power distribution network can be derived. This allows both frequency and transient responses to be done with SPICE simulation.     

Thoughts on using scientific system engineering method todevelop quantum computer

As the traditional semiconductor complementary metal oxide semiconductor(CMOS) integrated circuit technology gradually approaches the limit of Moore’s Law, quantum computing, as a new system computing technology, with the potential for higher computing speed and lower power consumption, is getting more and more attention from governments and research institutions around the world. For instance, the United States(US) government is adopting a bunch of bills to deploy new quantum information proces...     

基于快速鲁棒性特征匹配的目标识别

针对基于特征匹配的目标识别算法复杂度高、难以实时处理的问题,提出基于快速鲁棒性特征(SURF)的快速特征匹配算法.通过应用双阈值顺序聚类算法对特征点进行聚类,并对每一个聚类建立k-d搜索树,采用优先搜索算法匹配模板与图像的特征点,提高了算法实时性.采用RANSAC鲁棒估计算法消除错误匹配点对,计算模板与图像平面之间的单应矩阵,进而实现对目标的准确识别定位.仿真实验证明了算法的有效性和实用性.     

Spontaneous Directional Self-Cleaning on the Feathers of the Aquatic Bird Anser cygnoides domesticus Induced by a Transient Superhydrophilicity

In nature, the feathers of the goose Anser cygnoides domesticus stay superhydrophobic over a long term, thought as the main reason for keeping the surface clean. However, contaminants, especially those that are oleophilic or trapped within textures, cannot be removed off the superhydrophobic feathers spontaneously. Here, a different self-cleaning strategy based on superhydrophilic feathers is revealed that is imparted by self-coating of the amphiphilic saliva, which enables removing away low-surface-tension and/or small-size contaminants by forming directional water sheeting depending on their unique anisotropic microstructures. Particularly, the surface superhydrophilicity is switchable to superhydrophobicity upon exposure to air for maintaining a clean surface for a long time, which is further enhanced by coating with self-secreted preening oil. By alternate switching between a transient superhydrophilicity and a long-term stable superhydrophobicity, the goose feathers exhibit an integrated smart self-cleaning strategy, which is also shared by other aquatic birds. An attractive point is the re-entrant structure of the feathers, which facilitates not only liquid spreading on superhydrophilic feathers, but also long-term stability of the cleaned surface by shedding water droplets off the superhydrophobicity feathers. Thus, artificial self-cleaning microtextures are developed. The result renews the common knowledge on the self-cleaning of aquatic bird feathers, offering inspiration for developing bioinspired self-cleaning microtextures and coatings.     

Thin,Millimeter Scale Fingernail Sensors for Thermal Characterization of Nail Bed Tissue

Thin, flexible, body‐worn technologies that allow precise, quantitative monitoring of physiological status are of broad current interest due to their potential to improve the cost and effectiveness of healthcare. Although the surface of the skin represents one of the most widely explored points of integration, recently developed millimeter scale wireless sensor platforms allow deployment on alternative surfaces of the body, such as the finger/toenails and the teeth. The work described here introduces a collection of ideas in materials science, device engineering and computational techniques that enables precise characterization of the thermal transport characteristics of the nail bed tissue from measurements on the surface of the nail. Systematic in vitro studies demonstrate the underlying measurement principles, the theoretical models for optimized sensor design and the associated experimental procedures for determining the thermal conductivity of the tissue. Measurements performed on human subjects highlight capabilities in tracking changes in perfusion of the nail bed tissues in response to various external stimuli.