基于GSM之SMS的中央空调系统设计与实现

本文介绍了一个基于GSM的中央空调控制系统的设计与实现技术，内容包括该系统的系统结构、软件系统功能设计以及相关的关键技术。该系统已经得到实际应用，效果良好。     

Educational progression of second-generation immigrants and immigrant children

This paper provides important new insights into the reasons for the observed gap in educational attainment between children of immigrants and natives in Denmark using a dynamic discrete model of educational choices to determine at what stages of their educational careers children of immigrants face barriers to educational progression and how background characteristics affect educational choices at different points in the educational system. The main findings of the paper are that dropout rates from vocational upper secondary education are much higher among children of immigrants and that strengthening family characteristics reduces the dropout rates. However, behavioral differences and/or differences in constraints and institutional factors are also important barriers and thus determinants of the observed educational gaps as is age at immigration.     

具有监控数据远程传输功能的35KV变电所工程改造

变电所实现无人值守并具备遥测、遥信、遥控、遥调四遥功能,是推进技术进步,加强电网现代化管理,提高电网自动化水平,实现减人增效的重要手段,也是提高供电质量和可靠性,保证安全经济运行的迫切要求.     

On the control of solutions of a viscoelastic equation

In this paper we consider the semilinear viscoelastic equation

     

Demokratisches Prinzip, Gleichheitsgrundsatz, Hochschülerschaft, Organbestellung, Selbstverwaltung, Verhältniswahl

Dem Gesetzgeber kommt in der Frage, "in welcher Weise die demokratische Legitimation jener Selbstverwaltungsorgane, denen 'entscheidungswichtige Aufgaben' übertragen sind, sichergestellt werden kann, ein weiter rechtspolitischer Gestaltungsspielraum zu". Insoferne besteehen gegen die durch die angefochtenen gesetzlichen Bestimmungen vorgesehene indirekte Organbestellung als solche weder unter dem Aspekt des demokratischen Prinzips noch im Hinblick auf den Gleichheitsgrundsatz verfassungsrechtliche Bedenken.     

基于TC35i的GSM座机设计

介绍了一种使用普通电话座机连接西门子TC35i通信模块的方法,可实现电话呼出和接入功能。该系统使用STC单片机作为主控芯片,外接CM8880芯片作为按键式电话机的DTMF解码电路,同时采用NY3P065AP8语音芯片对按键及来电号码播报。系统通过两个RJ45接头与电话机及手柄相连,使用手机SIM卡通话,对大脑辐射很小。     

先进制造封装中Sb掺杂64Sn-35Bi-1Ag钎焊腐蚀和电化学迁移

采用动电位扫描结合SEM和XRD等技术研究先进电子制造封装过程中Sb掺杂对64Sn-35Bi-1Ag钎焊料在3%（wt.）NaCl溶液中腐蚀和电化学迁移行为影响。结果显示：Sb掺杂前后腐蚀电流密度（Icorr）随着Sb含量增加而有较显著的变化。其中当Sb含量小于1%时,随着Sb含量增加,其腐蚀电流密度（Icorr）减小。当Sb含量大于1%时,其腐蚀电流密度（Icorr）随着Sb含量的增大而增大;不论掺杂多少量,Sb掺杂后,钎料的腐蚀速率显著的增大,说明Sb掺杂后64Sn-35Bi-1Ag更易被腐蚀。电化学迁移结果显示,Sb掺杂前后,枝晶生长的速率显著不同,且枝晶成份有较大差异,掺杂后大于掺杂前,说明Sb掺杂不利于先进电子制造和封装技术。     

Trajectory tracking for a quadrotor under wind perturbations: sliding mode control with state-dependent gains

The problem of position tracking of a mini drone subject to wind perturbations is investigated. The solution is based on a detailed unmanned aerial vehicle (UAV) model, with aerodynamic coefficients and external disturbance components, which is introduced in order to better represent the impact of the wind field. Then, upper bounds of wind-induced disturbances are characterized, which allow a sliding mode control (SMC) technique to be applied with guaranteed convergence properties. The peculiarity of the considered case is that the disturbance upper bounds depend on the control amplitude itself (i.e. the system is nonlinear in control), which leads to a new procedure for the control tuning presented in the paper. The last part of the paper is dedicated to the analysis and reduction of chattering effects, as well as investigation of rotor dynamics issues. Conventional SMC with constant gains, proposed first order SMC, and proposed quasi-continuous SMC are compared. Nonlinear UAV simulator, validated through in-door experiments, is used to demonstrate the effectiveness of the proposed controls.