基于Kalman滤波的多尺度融合估计新算法

将信号的多尺度分析方法与多传感器数据融合技术相结合，基于某一尺度上给定的状态模型和在不同尺度上拥有不同采样率的多传感器分布式动态系统，提出了一种新的基于Kalman滤波的多尺度融合估计算法；在最细尺度上获得了基于全局信息的融合估计值；计算机仿真验证了算法的有效性。     

VPN 技术及其在无线局域网安全中的应用

本文对VPN网络安全技术进行了阐述,简单分析了VPN技术的原理 ,并对VPN技术在无线局域网中的应用提出了参考组网方式.     

柱形装药自由场水中爆炸气泡的射流特性

为研究柱形装药水中爆炸气泡射流特性,采用高速摄影方法在实验水箱中对PETN药柱进行水中爆炸实验,初步获得了有关柱形装药自由场水中爆炸气泡运动的数据资料.研究结果表明:柱形装药自由场水中爆炸形成气泡的运动与球形装药的存在差别,药柱放置方式的变化也会导致水中爆炸气泡产生性质迥异的运动.当药柱水平放置时,气泡表面的运动呈非对...     

酵母耐高温分子机制的研究进展

耐高温是酵母在工业生产中的重要特性之一.近年来,人们对耐高温酵母的应用研究日益重视并取得较大的进展,但其耐高温分子机制尚未明确.目前的研究结果表明,酵母耐高温机制涉及代谢网络调控、信号转导途径及多基因/蛋白共同作用等方面.本文从代谢途径、基因表达、酶活特性和蛋白质相互作用等4个方面综述当前酵母耐高温分子机制的研究进展,...     

EPON和GPON的比较

本文简要介绍了PON的历史和发展,并针对现今的两种主要的PON技术--EPON和GPON,从其技术特性方面和产品应用方面做了客观的比较和分析.并对于今后两者的发展做了展望.     

Cold atom space clock with counter-propagating atoms

<正>We discuss the feasibility of realizing a cold atom space clock with counter-propagating cold atoms in microgravity.The design of the space clock is based on an atomic beam clock with Ramsey cavity,except that magneto-optical trap(MOT) is placed at each side.Cold atoms are launched simultaneously from the MOTs at both sides of the clock and they move at the counter-direction towards each other.The velocity of the launched atoms is precisely controlled to Ramsauer-Townsend resonance so that no additional collision frequency shift takes place.Such configuration can efficiently cancel the frequency shift resulting from cavity phase shift and increase the signal-to-noise ratio(SNR).     

安徽畲族民歌的发展困境与传承路径

安徽省宣城市宁国市云梯畲族乡是安徽省唯一的民族乡,畲族民歌经历了五个发展时期,在安徽云梯畲族乡传承了百年,孕育了独特的闽皖调特色。安徽畲族民歌分为史歌、情歌、婚俗歌、叙事歌、哀歌等五种类型。随着城市化和现代化进程加快,安徽畲族民歌面临诸多发展困境,包括传承人群老龄化与断层、畲族语言应用氛围减弱和缺乏资金支持等。安徽畲族民歌的传承路径主要包括学校教育功能发挥、传承人引领示范、新媒体传播和文旅融合发展等。     

Miniaturized optical system for atomic fountain clock

Using modularized components, we have built a miniaturized optical system for 87Rb atomic fountain clock that is fitted on an 80 cm × 60 cm optical breadboard. Compared with the conventional optical setup on the table, our system is more compact, more robust and miniaturized. Taking advantage of this system, laser beams are transmitted through eight optical fibre patch cords from the optical breadboard to an ultra high vacuum system. This optical setup has operated for five months in our fountain system and required no alignment.     

Numerical simulation of trajectory and deformation of bubble in tip vortex

According to the behaviors of a bubble in the ship wake flow,the numerical simulation is divided into two stages,quasi-spherical motion and non-spherical motion,based on whether the bubble is captured by the vortex or not.The one-way coupled particle tracking method(PTM) and the boundary element method(BEM) are adopted to simulate these two stages,respectively.Meanwhile,the initial condition of the second stage is taken as the output of the first one,and the entire simulation is connected and completed.Based on the numerical results and the published experimental data,the cavitation inception is studied,and the wake bubble is tracked.Besides,the split of the bubble captured by the vortex and the following sub-bubbles are simulated,including motion,deformation,and collapse.The results provide some insights into the control on wake bubbles and optimization of the wake flow.     

基于 UML 的战士档案管理系统的分析与设计

本文对基于B/S架构的战士档案管理系统进行了分析,运用UML 建模方法对系统进行了可视化建模,并对系统模型进行了概括论证.