使用HTTP Tunneling技术实现穿透网络防火墙的通信

近年来,防火墙在网络中得到了广泛的应用.它能够比较有效地防范病毒与黑客的攻击,保护网络的安全.但是也带来了一些不利影响,使一些需要进行网络通信的应用软件系统不能正常工作.介绍一个解决方案,并且重点介绍通过HTTP Tunneling技术使用基于文本的HTTP协议传送二进制数据的方法.     

浅议各类数据的备份与归档管理

本文从各类数据在计算机中存在的状态以及在存储过程中的安全问题,对数据的安全性和保护性进行了论证。     

基于ATmega 128单片机的数字化地下管线定位仪

地下管线被视为城市的生命线。分析了地下管线定位仪的基本原理,并在此基础上详细介绍了基于ATmega 128单片机的数字化地下管线定位仪的硬件实现和软件实现,重点分析了基于磁保持继电器的分时供电电源电路。ATmega 128单片机实现了地下管线定位仪的数字化,使得定位仪能快速、准确地对地下管线进行水平定位和垂直定深。     

A piecewise analysis method to stability analysis of linear continuous/discrete systems with time‐varying delay

The delay‐dependent stability problem of linear continuous/discrete systems with time‐varying delay is investigated based on a piecewise analysis method (PAM). In the method, the variation interval of the time delay is firstly divided into several subintervals. By checking the variation of the Lyapunov functional in every subinterval, some new delay‐dependent stability criteria are derived. Several numerical examples show that our method can lead to much less conservative results than those in the existing references. Moreover, when the number of the divided subintervals increases, the corresponding criteria can provide an improvement on the results. Copyright © 2008 John Wiley & Sons, Ltd.     

基于投影匹配的钢坯端面字符快速识别方法

由于高温及复杂光照的干扰等成像环境的影响,钢坯端面字符自动识别存在很多困难,其实时自动识别难度大。现存的字符识别方法难以适应实际生产现场的需求。文章提出了一种基于投影匹配的快速识别方法,通过将图象二值化后进行垂直投影,直接将一维投影结果进行模板匹配,降低运算维数。大量的现场实验证明,该方法可有效的减少识别时间,提高生产效率,字符的拒识率和误识率较低,可满足生产线的实时要求。     

曼彻斯特编码技术在测井数据传输中的应用研究

基于曼彻斯特码编码技术文章提出一种适用于石油测井下行数据传输链路的设计方案。采用Verilog HDL设计的曼彻斯特编、译码器,在ALTERA公司的QuartusⅡ6．0软件平台上完成了仿真,并在FPGA器件上实现了硬件测试．最后下行数据传输链路的发送端和接收端在6km的电缆模拟器上完成了系统测试。通过计算机仿真和工程实现验证了该设计方法的正确性和实用性。     

大气湍流图像像素偏差机理分析

对大气湍流导致图像畸变和像素偏差的因素进行了深入分析,对大气湍流状态下激光发射远距离光束的光束漂移均方值进行仿真,分析光束漂移均方值曲线,为后续对图像畸变、像素偏差校正及克服湍流影响提供有效的理论依据。     

基于IP网络门禁控制系统通信模块的设计与开发

对基于IP网络的门禁控制系统整体设计方案及原理进行了简要的分析,提出了在系统框架上将B／S模式和C／S模式相结合的设计思想,同时通过引入通信模块,在管理软件和控制器之间架起了专用的TCP通道,给出了一种实现TCP／IP通信的新方法,并加入门禁控制器主动通信方式,测试证明该通信平台运行稳定,能够提高门禁控制系统的工作效率。     

In Situ Polymerizing Internal Encapsulation Strategy Enables Stable Perovskite Solar Cells toward Lead Leakage Suppression

Despite the outstanding power conversion efficiency (PCE) of perovskite solar cells (PSCs) achieved over the years, unsatisfactory stability and lead toxicity remain obstacles that limit their competitiveness and large-scale practical deployment. In this study, in situ polymerizing internal encapsulation (IPIE) is developed as a holistic approach to overcome these challenges. The uniform polymer internal package layer constructed by thermally triggered cross-linkable monomers not only solidifies the ionic perovskite crystalline by strong electron-withdrawing/donating chemical sites, but also acts as a water penetration and ion migration barrier to prolong shelf life under harsh environments. The optimized MAPbI₃ and FAPbI₃ devices with IPIE treatment yield impressive efficiencies of 22.29% and 24.12%, respectively, accompanied by remarkably enhanced environmental and mechanical stabilities. In addition, toxic water-soluble lead leakage is minimized by the synergetic effect of the physical encapsulation wall and chemical chelation conferred by the IPIE. Hence, this strategy provides a feasible route for preparing efficient, stable, and eco-friendly PSCs.