A novel dimesitylboron-substituted indolo[3,2-b]carbazole derivative: Synthesis,electrochemical, photoluminescent and electroluminescent properties

A novel indolo[3,2-b]carbazole derivative containing B(Mes)₂ groups, 5,11-dibutyl-2,8-bis(dimesitylboryl) indolo[3,2-b]carbazole (DBDMBICZ), was synthesized and structurally characterized by elemental analysis, NMR, MS. The thermal, electrochemical and photophysical properties of DBDMBICZ were characterized by thermogravimetric analysis, electrochemical methods, UV–vis absorption spectroscopy and fluorescence spectroscopy. DBDMBICZ exhibited high fluorescence quantum yields (Φ_max = 0.76) in solution and excellent thermal stability (T_d = 290 °C, T_g = 170 °C) and electrochemical stability. The multi-layered OLEDs devices with the configuration of ITO/NPB/CBP/light-emitting layer/Bphen/LiF/Al are fabricated by using DBDMBICZ as light-emitting layer. The devices show the same pure blue emissions at different voltages and relative good electroluminescent performances. The results indicate that DBDMBICZ has potential applications as an excellent optoelectronic material in optical field.     

Novel approach of distributed & adaptive trust metrics for MANET

It is known to all that mobile ad hoc network (MANET) is more vulnerable to all sorts of malicious attacks which affects the reliability of data transmission because the network has the characteristics of wireless, multi-hop, etc. We put forward novel approach of distributed & adaptive trust metrics for MANET in this paper. Firstly, the method calculates the communication trust by using the number of data packets between nodes, and predicts the trust based on the trend of this value, and calculates the comprehensive trust by considering the history trust with the predict value; then calculates the energy trust based on the residual energy of nodes and the direct trust based on the communication trust and energy trust. Secondly, the method calculates the recommendation trust based on the recommendation reliability and the recommendation familiarity; adopts the adaptive weighting, and calculates the integrate direct trust by considering the direct trust with recommendation trust. Thirdly, according to the integrate direct trust, considering the factor of trust propagation distance, the indirect trust between nodes is calculated. The feature of the proposed method is its ability to discover malicious nodes which can partition the network by falsely reporting other nodes as misbehaving and then proceeds to protect the network. Simulation experiments and tests of the practical applications of MANET show that the proposed approach can effectively avoid the attacks of malicious nodes, besides, the calculated direct trust and indirect trust about normal nodes are more conformable to the actual situation.

     

快速傅里叶变换的硬件实现

随着数字电子技术的发展,数字信号处理的理论和技术以及高密度,高集成度的FPGA得到广泛的应用。根据快速傅里叶变换(FFT)的特点,采用现场可编程逻辑器件(FPGA)并采用移位存储器存储旋转因子的方法来实现FFT的高速和实时性,采用XILINX公司的Virtex系列的芯片做验证。实验结果表明:该方法与一般的方法相比大大地提高了FFT的运算速度,满足了人们对实时性的要求。     

基于以太网的电力调度信息传输的开发

针对电力调度系统远程通信实时性传输的要求,分析了当前传统的电力调度通信系统的传输方法,以及以太网通信协议在信息远程传输的应用,重点结合电力系统应用的实际要求,给出了以太网在电力调度信息传输系统中的应用,从以太网应用模式、以太网通信模块设计以及数据传输机制三个方面进行了分析研究,对于进一步提高电力调度系统信息传输的实时性具有一定借鉴意义。     

基于ARM和FPGA的视频监控系统设计

设计并实现了一种基于ARM+FPGA的视频监控系统,以ARM9处理器为主控制器,FPGA为协处理器,构造ARM与FPGA间的高速数据传输通道和基于Linux的轻量级的图形驱动,完成实时视频采集和显示。实验结果表明,该设计能够流畅播放PAL/NTSC两种制式视频信号,具有良好的扩展性、稳定性和较快的响应速度。     

航电系统内部的电磁兼容性分析与测量

通过实际测试详细研究了航电系统内部的电磁干扰问题,说明了其典型的干扰途径,包括传导干扰、接地干扰、辐射干扰以及综合电磁环境干扰等四种,分析了传导干扰与辐射干扰的测试方法及主要的干扰特征,并讨论了降低干扰的一些具体途径.     

基于流量负载的改进型几何抽样算法

为了解决在流量高峰时期网络节点由于超负荷工作导致报文丢失的问题,在几何抽样的基础上,设计了一种能自动适应流量负载变化的抽样算法.该算法在流量高峰时会根据负载情况动态地计算最佳的抽样概率来匹配节点的处理能力从而降低节点丢失的报文数,在流量负载轻时会自动地提高抽样概率以充分利用节点的处理性能.通过真实网络流量数据的实验分析表明,改进后的几何抽样算法不仅能有效降低节点丢弃的报文数,同时还提高了网络测量的精度,证明了该改进算法对流量负载具有良好的适应性.     

基于AdaBoost的组合网络流量分类方法

针对单一分类方法在训练样本不足的情况下对于小样本网络流分类效果差的特点,通过自适应增强(Adaptive Boosting,AdaBoost)算法进行流量分类。算法首先使用CFS(Correlation-based Feature Selection)特征选择方法从大量网络流特征中提取出少量高效的分类特征,在此基础上,通过AdaBoost算法组合决策树、关联规则和贝叶斯等5种单一分类方法实现流量分类。实际网络流量数据测试表明,基于AdaBoost的组合分类方法的准确率在所选的几种算法中是最高的,其能够达到98192%,且相对于单一的分类算法,组合流量分类方法对于小样本网络流的分类效果具有明显提升。     

基质固相分散-高效液相色谱法测定食物中痕量异丙威和溴氰菊酯

本文研究了应用基质固相分散(MSPD)处理复杂样品技术与高效液相色谱法相结合测定食物中痕量异丙威和溴氰菊酯残留物的新方法。介绍了MSPD技术进行前处理的实验条件并讨论了与传统残留分析的区别。本文将MSPD技术用于水果、粮食等食物中异丙威和溴氰菊酯残留物的高效液相色谱分析,并对定量检测条件作了详细的研究。     

南通市区无障碍环境建设现状分析和对策研究

详细地阐述了南通市无障碍环境建设的现状,系统的对南通无障碍环境建设中存在的问题进行了分析,并结合南通的实地情况提出了循序渐进的进行无障碍环境建设,加强无障碍环境设施的维护和管理,对无障碍设施产品的开发、经营实施奖惩制度等可行性的对策。