毫米波LTCC组件中的波导-微带转换

介绍了Ka波段LTCC(低温共烧陶瓷)组件中矩形波导-微带的一种新型转换结构。这种转换结构通过波导和微带间的开槽耦合以及在LTCC多层布线基板中用金属填充通孔阵列等效替换波导壁而实现。此类型波导到微带的转换无需将安装在波导内的LTCC基板加工成特殊形状,便于加工,而且转换对LTCC基板和波导的机械安装公差要求较低。     

密码学在产品数据管理领域的应用

人类进入了网络时代,企业为了提升竞争力,纷纷上马ERP,MIS,PDM等应用系统,而这些系统也渐渐从局域网扩展到互联网.网络安全,数据安全正受到日益关注.文章就计算机密码学在企业PDM（产品数据管理）中的应用作一探讨.     

Mesoporous TiO2 nano-spheres: Electrospray combined sol-gel fabrication and application to organic phosphorus degradation

In this work, electrospray technique combined sol-gel method was used to prepare porous TiO2 film. X-ray Photoelectron Spectroscopy (XPS), X-Ray Diffraction (XRD), and Scanning Electron Microscope (SEM) analyses were conducted to examine the chemical composition, phase structure, and surface morphology of the sprayed TiO2 film. After calcined at 450℃ in air atmosphere for 2 h, mesoporous TiO2 nano-spheres clusters were formed on the surface of silicon wafer and the average size of nano-spheres was 250 nm. Ti presented as Ti 4+ oxidation state in TiO2 film, and the TiO2 film exhibited the anatase phase. The sprayed porous TiO2 films were employed as photocatalyst to degrade organic phosphorus in water samples. Compared with the TiO2 film prepared by Sol-Gel spin-coating method, the porous TiO2 film deposited by electrospray combined sol-gel method showed higher photocatalytic activity.     

Experiment and analysis of the effect of fine tracking system on the unstable platform in laser communication

Atmospheric turbulence and platform vibration in the space optical communication can cause the offset and jitter of beam, which further result in the fluctuations of received optical power. To resist this effect, a communication system with fine tracking systems in the receiver and transmitter is designed. The system is used in the experiment of laser communication between high-rise buildings over a distance of 3.5 km. After adding a vibration source to the transmitter, the centroids of spots captured by the camera of the transmitter and the optical power of receiver are recorded for the purpose of analysis. When the vibration source works at the designated frequency, a peak appears at the corresponding frequency in the spectrum of the spot centroids and the optical power of receiver. Then the peak disappears once the fine tracking system begins to work. Compared with the condition without the fine tracking system, the minimum value of the optical power of receiver is increased by 5 dB, and the standard deviation is decreased by 30%.     

基于TDLAS的非均匀流场温度分布的测量

基于可调谐半导体激光吸收光谱（TDLAS）温度测量技术,使用多条谱线能够实现非均匀流场的气体温度分布的测量,主要有剖面拟合和温度离散两种方法。对剖面拟合方法进行理论分析和仿真,并且假设电炉上方0.5 cm处的温度分布为二次函数ax2+bx+c,采用剖面拟合方法进行测量,与热电偶测量的温度进行对比,温度最大波动为49 K。     

Home Health Gateway Based Healthcare Services Through U-Health Platform

The Ubiquitous Health, or u-Health, service is an IT health care service using the ubiquitous computing environment. U-Health provides customized medical services. As it is a service that has developed from the current hospital visiting medical system, the u-Health service provides a patient with healthcare anywhere and anytime. In this paper, we propose a home health gateway based healthcare services through the u-Health platform. Using home health gateway, u-Health can provide health monitoring, diet, and exercise services using the healthcare decision support module in the ubiquitous environment. This approach would offer specialized services using an external content provider of DB. In addition, a doctor can provide advice to patients using the monitoring service. The proposed u-Health platform provides effective services using home health gateway in ubiquitous environments to customers, which will improve the health of chronic patients.     

Cryptanalysis of two password authenticated key exchange protocols based on RSA

In 2002, Zhu et al. proposed a password-based authenticated key exchange protocol based on RSA. Many researchers pointed out that Zhu et al.'s protocol is vulnerable to off-line dictionary attack. In 2003, Yeh et al. proposed an improved protocol. Recently, Lo and Yang-Wang pointed out that Yeh et al.'s improved protocol is also vulnerable to offline dictionary attack. To avoid this weakness existed in Yeh et al.'s protocol, Lo and Yang-Wang proposed two improved protocols. However, in this letter, we show that the Lo protocol is vulnerable to an active off-line dictionary attack and the Yang-Wang protocol is vulnerable to a passive off-line dictionary attack.     

浅析集中化的收入管控系统规划及应用

首先介绍了运营商收入现状,然后针对目前收入系统中存在的问题进行了说明,分析了目前存在的问题,并提出了相应的解决方案,主要是从收入源头进行管控,重点管崆套餐业务和融合业务所涉及的分摊操作,以及业务收入向财务收入转换的业会转换环节。     

Transient luminescence in organic light-emitting diodes explained by trap-assisted recombination of stored charges

We show that after voltage turn-off the recombination of the charges which are stored in the on-state may follow a trap-assisted mechanism instead of the Langevin formula in organic light-emitting diodes. A microscopic model based on this form of recombination is introduced, which not only fits the transient electroluminescence very well in the whole range of the off-state but also provides parameters quantitatively characterizing the stored charges in the on-state. In the last part, we briefly compare the work by Weichsel et al. [1] and our model, trying to constitute a comprehensive picture of the stored charges in OLEDs. As an OLED model system we have chosen a host/guest system co-doped with red and green phosphorescent emitters.     

二维谐振子调制势中光束传输特性研究

运用自相似方法,求出了二维谐振子调制势下光束的传输方程的精确解析解,并对光束在传输距离一定时其传输特性随量子数的变化规律进行了数值分析.结果表明,在谐振子势调制下,光束传播的波函数解为厄米特函数,且在能量峰值上表现出类似于亮孤子的中间能量高于外围能量的特性,在几何分布上形成矩阵或方阵式波包.波包总数受x、y方向的量子数取值影响,波包能量幅值沿x、y轴的正负向均逐渐增大且关于矩阵的对角线或x、y轴对称。