为提高酶催化过程中pH值的控制精度,采用了具有参数自适应及Hammerstein模型2种相结合的控制策略方法,利用递推最小二乘进行参数估算,在控制器里颠倒静态非线性特性来对过程非线性部分进行补偿。此方式用于酶催化过程中的pH值过程控制,...为提高酶催化过程中pH值的控制精度,采用了具有参数自适应及Hammerstein模型2种相结合的控制策略方法,利用递推最小二乘进行参数估算,在控制器里颠倒静态非线性特性来对过程非线性部分进行补偿。此方式用于酶催化过程中的pH值过程控制,其试验结果不仅可使pH值高度非线性控制转换成一个近似的线性控制,并自动地改变控制器的整定参数,从而解决pH中和过程的高度非线性控制难点,还可达到提高酶催化过程中pH值的控制精度、提高酶的催化响应效果的目的。pH中和过程的计算机仿真结果表明,该控制算法比比例积分微分(proportion integral differential,PID)控制具有更好的控制品质。由于该控制主要是针对pH值的控制,有较强的通用性,具有典型应用价值和推广意义。展开更多
This essay studies various family-related factors that influence a child’s academic achievement in school in P.R. China. The factors are illustrated under three categories: the family’s social class and education, e...This essay studies various family-related factors that influence a child’s academic achievement in school in P.R. China. The factors are illustrated under three categories: the family’s social class and education, early home environment and family material condition. The author discusses the relevant factors by way of relating the knowledge of social environment to his own experiences as a student and then teacher in China. The essay closes with a discussion directing the public’s attention to the concern about home-related factors influencing a child’s academic achievements in school.展开更多
文摘为提高酶催化过程中pH值的控制精度,采用了具有参数自适应及Hammerstein模型2种相结合的控制策略方法,利用递推最小二乘进行参数估算,在控制器里颠倒静态非线性特性来对过程非线性部分进行补偿。此方式用于酶催化过程中的pH值过程控制,其试验结果不仅可使pH值高度非线性控制转换成一个近似的线性控制,并自动地改变控制器的整定参数,从而解决pH中和过程的高度非线性控制难点,还可达到提高酶催化过程中pH值的控制精度、提高酶的催化响应效果的目的。pH中和过程的计算机仿真结果表明,该控制算法比比例积分微分(proportion integral differential,PID)控制具有更好的控制品质。由于该控制主要是针对pH值的控制,有较强的通用性,具有典型应用价值和推广意义。
文摘This essay studies various family-related factors that influence a child’s academic achievement in school in P.R. China. The factors are illustrated under three categories: the family’s social class and education, early home environment and family material condition. The author discusses the relevant factors by way of relating the knowledge of social environment to his own experiences as a student and then teacher in China. The essay closes with a discussion directing the public’s attention to the concern about home-related factors influencing a child’s academic achievements in school.
