大容量机组圆形烟道设计特点

针对大容量机组的烟道形式问题,结合顺德德胜电厂的烟道设计,对比了圆形和矩形两种烟道的特点和用料量,介绍了圆烟道的设计参数及加固肋设置情况,可供设计人员参考。     

Application of electrolyzed functional water on producing mung bean sprouts

Electrolyzed functional water possesses a wide variety of antimicrobial activities. Electrolyzed functional water, which used to take place of tap water in producing mung bean sprouts, was studied in this paper. The results showed that electrolyzed water can not only reduce the quantity of microorganism on the surface of mung bean sprouts, but also promote the growth of sprouts. Further research showed that electrolyte leakage rate of mung bean soaked in electrolyzed water was the lowest, while the catalase’s activity of mung bean soaked in electrolyzed water was the highest. All of these contribute to the high activity of mung bean.     

A Novel Method for Calculation of Eigenmodes of Gyrotron Resonators

A new method for calculating the eigenmodes of gyrotron resonators is presented. With this method, the resonant frequency, Q-factor and field profiles of the eigenmodes are determined through finding the minimum value of a function of two variables, namely the resonant frequency and the Q-factor. Compared with the traditional calculation method, the new method predicts a significantly higher Q-factor of the eigenmodes.     

Effect of Electromagnetic Stirring on Solidification Structure of Incoloy 825 Superalloy

Superalloy Inconel 825 has been extensively used in chemical industry and transportation industry due to its excellent creep rupture strength and prominent corrosion resistant properties under various circumstances.However,the mass production of this alloy by continuous casting method is restricted because of the serious macrosegregation and coarse grains in the billet.In current,a linear travelling magnetic field was introduced in the solidification process of Inconel 825 with the aim of changing the fmal microstructure by electromagnetic stirring(EMS)force.The results have indicated that the dendrite structure of Incoloy 825 is refined obviously with applying EMS,and the mechanism of dendrite refinement is presumed to the introduction of a forced convection within the solidifying melt.Moreover,The number and the size of precipitated phases including carbide and nitride were found to be significantly reduced with EMS,a phenomenon on the reduction of interdendritic segregation of titanium and molybdenum was simultaneously observed,which demonstrated that he release of interdendritic segregation by EMS inhibits the growth dynamic of carbide and nitride from the melt.     

A DCT-based multipoint video composition scheme

针对视频会议应用中传统的像素域多路视频混合方法存在运算复杂度高、画面质量损伤的问题,提出了一种基于压缩域的替代方法,并给出了详细的码流映射算法步骤.该方法按照混合后多画面的空间位置关系,通过对输入的多路码流中宏块编码次序的重排和语法元素的映射,在码流级别将多路视频合成到同一画面中,并采取提前量化策略消除可能出现的二次量化失真,从而可兼具处理速度快和高保真的双重优点.以H.263为例验证了此方法的有效性.实验结果表明,与编解码器级联的方法相比,此方法的峰值信噪比(PSNR)平均提高2dB,运算效率提高百倍以上.此研究工作有望为正在制定的国际视频编码标准H.265贡献一种视频混合解决方案.     

纳米磁性Mn3O4粉末的溶剂热法合成及表征

以MnO2为主要原料,应用溶剂热法合成了纳米磁性Mn3O4粉体.研究和讨论了反应温度、填充度、溶剂种类、降温速率对产物性能的影响,得到溶剂热法制备纳米磁性Mn3O4的最佳条件.产物经XRD表征为单一相Mn3O4,经粒度分析仪及透射电镜(TEM)检测,为四方晶型,平均粒径为55nm.     

纳米二氧化钛等离子体放电催化杀菌的试验研究

论文提出了纳米二氧化钛等离子体放电催化灭菌消毒的新方法,介绍了纳米二氧化钛等离子体放电催化的原理和装置,进行了杀灭芽孢杆菌的试验研究.试验证明,纳米二氧化钛等离子体放电催化具有很强的灭菌能力,一分钟内即可将105数量级的芽孢杆菌百分之百杀灭.     

采用一种优化编码方法的光学相关器在目标识别中的应用

VanderLugt相关器在纪录目标图形的傅里叶变换复振幅谱时,通常需要引入一个离轴的参考光波来纪录复振幅信息.本文利用计算机制匹配滤波器,对四级迂回相位编码方法进行了优化,事先生成不同目标的匹配滤波器进行目标识别,从而大大简化了实验方案,保证了VanderLugt相关器工作的实时性.实验结果显示了该方法的可行性.     

CLTC: a cluster-based topology control for ad hoc networks

The topology of an ad hoc network has a significant impact on its performance in that a dense topology may induce high interference and low capacity, while a sparse topology is vulnerable to link failure and network partitioning. Topology control aims to maintain a topology that optimizes network performance while minimizing energy consumption. Existing topology control algorithms utilize either a purely centralized or a purely distributed approach. A centralized approach, although able to achieve strong connectivity (k-connectivity for k /spl ges/ 2), suffers from scalability problems. In contrast, a distributed approach, although scalable, lacks strong connectivity guarantees. We propose a hybrid topology control framework, cluster-based topology control (CLTC) that achieves both scalability and strong connectivity. By varying the algorithms utilized in each of the three phases of the framework, a variety of optimization objectives and topological properties can be achieved. In this paper, we present the CLTC framework; describe topology control algorithms based on CLTC and prove that k-connectivity is achieved using those algorithms; analyze the message complexity of an implementation of CLTC, namely, CLTC-A, and present simulation studies that evaluate the effectiveness of CLTC-A for a range of networks.     

SnSe薄膜的两步法制备与光电性能研究

采用电子束蒸镀预制层,再对预制层进行硒化的两步法工艺,通过调节硒化温度和退火时间,在玻璃基底上成功制备了SnSe薄膜。利用X射线衍射、拉曼光谱、扫描电子显微镜、紫外可见近红外分光光度计等研究了SnSe薄膜的物相、微观形貌和光学性能。结果表明,在450℃下硒化退火60min可制备出纯相的多晶SnSe薄膜,其带隙为0.93eV。在功率为200mW/cm²的980nm激光照射下,对SnSe薄膜进行了光电响应特性测试,通过曲线模拟得出所制薄膜的响应时间和恢复时间分别为62和80ms。