“电气工程基础”教学理念与方法研究

"电气工程基础"是电气学科大类中的一门重要专业基础课程,是承接基础课教学与专业课教学的关键环节.围绕"电气工程基础"课程在学科大类中的专业定位,本文从教学理念的层面和教学过程的设计方面进行了深入的探讨.结合课程组多年的教学实践,总结了本课程在教学方法以及现代教育技术应用方面的一些经验和体会.     

径流中长期预报模糊识别优化模型及应用

对水文中长期预报模糊识别方法进一步研究,基于模糊环境下的目标函数,提出了具有主观监督因子和稳定系数的模糊识别预报模型.根据已知样本的最优模糊划分建立预报模型,利用已知样本的指标和样本的最优模糊划分计算预报模型的参数,给定模型的稳定系数,再通过调整主观监督因子对预报模型参数进行优化.径流中长期预报实例的模型检验平均相对误差为7.84%.     

移动话务网管系统的改进方案

为了中国移动"集中监控、集中维护、集中管理"的集中化运维模式可靠实施,本文提出了在现运行网管平台基础上,采取话务网管系统硬软件双备份技术改造方案.     

通信局(站)电源、空调及环境集中监控管理系统标准的探讨

本文介绍了通信局(站)电源、空调及环境集中监控管理系统的热点问题和行业标准的修订情况.     

软件第三方定型测评与质量保证

软件第三方定型测评是装备配套软件研发过程中的重要环节,对软件质量保证至关重要。加强对软件第三方测评的质量监控,能够提高软件可靠性,从而大大提高装备效能。文中介绍了软件第三方测评的相关知识、软件质量保证的方法以及二者之间的关系,并以典型电子信息系统软件的定型测评为例进行了验证。验证结果表明,软件第三方定型测评可以使该系统软件质量得到保证和提高。     

基于神经网络的洪水水位预测算法

鉴于洪水变化难以预料,及其给社会和人民群众带来的危害,提出一种新的洪水水位变化的预测算法.利用神经网络能以任意精度逼近非线性函数的特点,采用神经网络的有监督式学习,并将预测误差作为反馈来调整水位预测网络中的权值分布,以达到学习的目的.通过程序编程对此算法进行调试,得到了较理想的预测效果.     

提高话务承载能力与载频收益的综合优化方案

基于对广西联通GSM网络现状的分析,通过专题优化项目的实践验证,总结出一套全面、系统的资源优化流程:通过综合运用各种操作性较强的非资本性优化手段,可有效地缓解网络拥塞,提高整网的话务承载能力与载频收益。     

基于以太网的数字电视复用器远程监控以及数据插入方案的研究和设计

首先介绍基于NIOSⅡ的数字电视复用器的设计原理,在此基础上提出一种基于网络控制芯片LAN91C111的复用器远程监控和EPG信息插入的方案,并将它与现有各种方案进行比较,该方案的优势在于:将系统监控和EPG信息插入在同一控制软件中实现,并且使用一台主机可以控制多台复用器,系统集成度高、成本低,有很强的实用性,最后详细说明该方案的实现原理。     

Highly stereoselective synthesis of (Z)-3-methoxy-1-methyleneisoindoles via DMAP catalyzed cyclization of methyl 2-alkynylbenzimidates

A DMAP (4-dimethylaminopyridine) catalyzed cyclization of methyl 2-alkynylbenzimidates has been developed, which affords 3-methoxy-1-methyleneisoindoles with excellent Z-stereoselectivity under mild and transition-metal-free conditions. The (Z)-3-methoxy-1-methyleneisoindole products can be converted to corresponding 3-amino-1-methyleneisoindoles, 3-methoxy-isoindoles, 3-methyleneisoindolinones and isoindolinones with high efficiency.     

Benchmarking the accuracy of coverage-dependent models: adsorption and desorption of benzene on Pt (1 1 1) and Pt3Sn (1 1 1) from first principles

Bimetallic catalysts have demonstrated properties favorable for upgrading biofuel through catalytic hydrodeoxygenation. However, the design and optimization of such bimetallic catalysts requires the ability to construct accurate, predictive models of these systems. To generate a model that predicts the kinetic behavior of benzene adsorbed on Pt (1 1 1) and a Pt₃Sn (1 1 1) surface alloy (Pt₃Sn (1 1 1)), the adsorption of benzene was studied for a wide range of benzene coverages on both surfaces using density functional theory (DFT) calculations. The adsorption energy of benzene was found to correlate linearly with benzene coverage on Pt (1 1 1) and Pt₃Sn (1 1 1); both surfaces exhibited net repulsive lateral interactions. Through an analysis of the d-band properties of the metal surface, it was determined that the coverage dependence is a consequence of the electronic interactions between benzene and the surface. The linear coverage dependence of the adsorption energy allowed us to quantify the influence of the lateral interactions on the heat of adsorption and temperature programmed desorption (TPD) spectra using a mean-field model. A comparison of our simulated TPD to experiment showed that this mean-field model adequately reproduces the desorption behavior of benzene on Pt (1 1 1) and Pt₃Sn (1 1 1). In particular, the TPD correctly exhibits a broadening desorption peak as the initial coverage of benzene increases on Pt (1 1 1) and a low temperature desorption peak on Pt₃Sn (1 1 1). However, due to the sensitivity of the TPD peak temperature to the desorption energy, precise alignment of experimental and theoretical TPD spectra demands an accurate calculation of the adsorption energy. Therefore, an analysis of the effect of the exchange-correlation functional on TPD modeling is presented. Through this work, we show the necessity of incorporating lateral interactions into theoretical models in order to correctly predict experimental behavior.