基于史密斯圆图分析射频放大器的设计

分析了史密斯圆图与射频放大器的基本理论，研究了将史密斯圆图应用于射频放大器电路的设计．着重对提高电路稳定度和线性度、降低噪声系数和改善输入输出特性进行了分析研究．通过实例分析可得该放大器的增益为20dB，噪声系数最小为2dB，电压驻波比为1．7：1．仿真结果表明该放大器的设计方法具有良好的可行性和实用性。     

Prediction of chaotic systems with multidimensional recurrent least squares support vector machines

In this paper, we propose a multidimensional version of recurrent least squares support vector machines （MDRLS- SVM） to solve the problem about the prediction of chaotic system. To acquire better prediction performance, the high-dimensional space, which provides more information on the system than the scalar time series, is first reconstructed utilizing Takens＇s embedding theorem. Then the MDRLS-SVM instead of traditional RLS-SVM is used in the high- dimensional space, and the prediction performance can be improved from the point of view of reconstructed embedding phase space. In addition, the MDRLS-SVM algorithm is analysed in the context of noise, and we also find that the MDRLS-SVM has lower sensitivity to noise than the RLS-SVM.     

新显色剂咪唑偶氮对甲苯的合成及其与钴的显色反应

合成了一种新的杂环偶氮类显色试剂 2 - ( 2′-咪唑偶氮 ) - 4-甲基苯 ( IAP-4M) ,进行了结构鉴定和光度性质测试。研究了该试剂与钴的显色反应的适宜条件 ,并应用于维生素 B12 、水样中微量钴的测定 ,络合物的摩尔吸光系数为 1 .1 6× 1 0 5L·mol-1· cm-1。