我对早年搞控制的一些回忆

近100年中国的历史可以称得上是沧桑巨变的历史,提起四五十年前的事,对于年轻人说来—陌生而又遥远,但对我们曾经经历过的人说来虽恍如隔世,但却仍有很多总也抹不去的回忆,有些是美好的但不少是苦涩的.国际自控联(IFAC)是1960年正式成立的,中国是发起国之一,第一次IFAC大会在莫斯科召开,中国派了一个代表团.北京大学由一个搞流体力学的老师参加,因为他当时是数力系的科研秘书.代表团团长是自动化所的领导武汝扬,他在大会致辞中提到中国要坚定地高举总路线、大跃进、人民公社三面红旗前进,将政治口号带进了国际学术会议.后来传达会议的人讲这使会议参加者感到震动,因此收到了很好的政治效果.     

THE RELATIONSHIP BETWEEN THE STABILITY AND THE OPTIMALITY OF LINEAR SYSTEMS(Ⅱ)

Different from the inverse problem put forward by R.E.Kalman, another kind ofinverse problem of linear optimal control is proposed and discussed in[1] as follows:Givenan asymptotically stable linear constant system and a nonnegative quadratic performanceindex, when can a state-feedback be separated from the stable system so that this state-feedback control law is optimal for the given index? In this paper this problem is extended.Similar conclusions are obtained for linear discrete systems and linear time-variablesystems. According to these conclusions we can say that the correspondence between theasymptotically stable system and the optimal feedback system is the inherent character ofall kinds of linear systems.     

Rapid detection of chlorpheniramine maleate by an electrochemical sensor based on metal-organic frameworks CHP@Cu3（BTC）2 /MWCNTsEI北大核心CSCD

Copper hydroxyphosphate@metal-organic frameworks/multi-wall carbon nanotube composites （CHP@Cu3 （BTC）2 /MWCNTs）were prepared by a new in-situ template method and then an electrochemical sensor was developed based on the composites. The crystal structure and morphology of the material were characterized by X-ray diffraction and scanning electron microscope. Cyclic voltammetry and linear sweep voltammetry were used to study the electrochemical catalytic performance，and the determination conditions were optimized. The rapid and sensitive detection of chlorphenamine maleate was realized. There was a good linear relationship between the oxidation peak current and concentration of chlorphenamine maleate in the ranges from 5 to 100 µμmol/L and from 150 to 800 µμmol/L，and the linear equations were as Ipa （µμA）=0.1559c（µμmol/L）-0.3533 （R2 =0.9973）and Ipa （µμA）=0.02328c（µμmol/L）+16.63（R2 =0.9594），and the detection limit was 1.67 µμmol/L. The recoveries of the actual drug ranged from 91.0% to 109.1%. © 2023, Youke Publishing Co.,Ltd. All rights reserved.