一种基于PDA的掌上控制器的通信软件设计与实现

串口通信广泛应用于工业控制领域,PDA利用自身串口通信功能和使用方便的特点,使得以它制作的线控掌上控制器具有广泛的应用范围和良好的应用前景.介绍了利用EVC实现PDA和VxWorks通信软件的关键技术.     

基于中国剩余定理的入侵容忍CA方案

在介绍和分析了中国剩余定理和t-out-of-n秘密共享方案的基础上,提出了一个基于中国剩余定理的门限数字签名方案和一个基于离散对数的零知识证明方法.设计了一个具有入侵容忍功能的认证机构,并将中国剩余定理与RSA结合实现签字运算.此系统不仅有效地解决了私钥的秘密共享,而且减少了系统的计算量,提高了系统的运算效率.     

Multistep impregnation method for incorporation of high amount of titania into SBA-15

A multistep impregnation method was employed to incorporate high amount of titania into the mesoporous SBA-15 silica. No damage to the SBA-15 silica mesostructures was caused by the loading of titania in every cycle. The existence of titania small nanodomains were confirmed to be present by Raman spectra and UV–vis DRS measurements. High dispersion of them was realized via this method according to the results of low-angle X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and N₂ sorption measurements. Importantly, no blockage of mesostructures was acknowledged with titania content up to 24.4 wt.%. In comparison, normally used one-step impregnation method led to serious blockage of mesopores as the results of formation of bulk titania particles in the mesochannels. Photo-activity test for the removal of oestrogen showed the superiority of the materials synthesized by multistep impregnation method to one-step impregnation method.     

Semiconductor/porous silica glass nanocomposites via the single-source precursor approach

The utilization of single-source molecular precursor approach to obtain II–VI and IV–VI semiconductors encapsulated in porous Vycor glass (PVG) is described. The procedure is based on the impregnation of cadmium and lead(II) diethyl-dithiocarbamate complexes, Cd(S₂CNEt₂)₂ and Pb(S₂CNEt₂)₂, inside the porous environment of PVG followed by a thermal treatment of the glass. The pyrolysis of the impregnated precursor gives rise to binary semiconductors CdS and PbS, respectively. The impregnation step is driven by interactions between the precursors and active sites located at glass pore surfaces. After completing the impregnation–decomposition cycle, it was found that the active glass sites were regenerated, making new cycles possible. The amount of encapsulated semiconductor increases linearly as a function of the number of cycles. Nanocomposites obtained after 1–10 cycles were prepared and characterized by optical spectroscopy, X-ray diffraction powder and transmission electron microscopy.     

Formation of lanthanum beryllate real structure under different crystallization conditions

The aim of this paper is to characterize the major structural defects of lanthanum beryllate single crystals grown by the Czochralski method, including those doped with rare-earth elements, and to reveal their relationship to specific properties of the crystal structure of La₂Be₂O₅ and with their crystallization conditions. As a basic method for research, we used transmission X-ray topography. It was established that the defect state of La₂Be₂O₅ crystals prepared by this method can be caused by different types of dislocations and their ordered assemblies, solid-phase inclusions of crucible metal and eutectically co-crystallizing phases, as well as by face growth sectors with elevated content of dopant. We show a possibility for growing single crystals of doped lanthanum beryllate having a minimum quantity of structural defects that could be suitable for manufacture of high quality laser rods.     

Influence of CuO addition to BaSm2Ti4O12 microwave ceramics on sintering behavior and dielectric properties

Microwave dielectric ceramics of tungsten–bronze-type BaSm₂Ti₄O₁₂ were prepared by doping CuO (up to 2 wt.%) as the liquid-phase sintering aid. The effects of CuO additive on the densification, micro structure and dielectric properties were investigated. Due to the liquid-phase effect, the sintering temperature of BaSm₂Ti₄O₁₂ ceramics with 1 wt.% CuO addition can be effectively reduced to 1160 °C, about 200 °C lower than that of pure BaSm₂Ti₄O₁₂ ceramics, while good microwave dielectric properties of ɛ_r = 75.8, Q*f = 4914.6 GHz and τ_f = −7.65 ppm/°C were still achieved.     

Lithium solubility limit in ZnGa2O4:Bi0.0013+,Li+ phosphor

The lithium solubility limit, photoluminescence (PL) and photoluminescence excitation (PLE) properties of lithium ion co-activated ZnGa₂O₄:Bi³⁺,Li⁺ phosphor have been investigated. A LiGaO₂ second phase began to appear from 3 mol% Li⁺ ion co-activated ZnGa₂O₄:Bi³⁺,Li⁺ phosphor. The enhanced brightness of blue (λ_ex = 254 nm) and white (λ_ex = 315 nm) colors of bismuth ions doped ZnGa₂O₄:Bi³⁺,Li⁺ phosphor was assigned to the formation of LiGaO₂. Bi³⁺ activated lithium zinc gallate phosphor showed a more enhanced PLE peak around 315 nm than that of lithium zinc gallate phosphor when λ_em = 520 nm. Thus, we observed that the PL intensity of ZnGa₂O₄:Bi³⁺,Li⁺ phosphor with λ_em = 520 nm was much greater than that of ZnGa₂O₄:Li⁺ phosphor. Also, ZnGa₂O₄:Bi³⁺,Li⁺ phosphor exhibited a shorter decay time than that of ZnGa₂O₄:Li⁺ phosphor by about a factor of about 2.     

基于Volterra泛函级数的非线性系统的鲁棒辨识

针对弱非线性系统的鲁棒建模问题, 基于Volterra泛函级数, 结合集员辨识理论, 提出了广义频率响应函数的鲁棒辨识方法, 形成了一套较完整的弱非线性系统的鲁棒建模方法, 仿真结果表明该方法是行之有效的.     

A New Grade Carbon Black Produced by Thermal Plasma Process

This paper presents a new route about producing carbon black,by wich the natural gas cracking is carried out in the absence of oxygen thanks to an electric energy supply externally given by a plasma jet.The carbon black produced by this process has a narrow size distribution and a small average diameter of 38nm as well as a highly branched aggregate.The higher DBP value of 1.40ml/g shows it should be a high structure carbon black.The FTIR spectra shows that there are lots of aromatic c-c bonds and a large amount of nitrogen-coutaining functional groups on the carbon blacks surface,such as-NH,-CN as we3ll as -CH,-OH,-COOH groups.     

基于量测数据相关性的电力系统不良数据检测和辨识新方法

电力系统量测数据的质量是影响电力系统状态估计效率和结果的重要因素,而量测数据中客观地存在少量不良数据,检测和辨识这些不良数据是电力系统状态估计的重要组成部分。文章分析了量测数据协方差矩阵中的元素值在量测数据中含有白噪声、突变量和不良数据时的变化规律,提出了通过量测数据协方差矩阵中元素的变化规律检测和辨识不良数据的新方法,在IEEE14节点系统上的仿真试验验证了该方法的正确性。