Background Generally speaking. Chinese college graduates in the fifties and sixties took Russian as their second language, and those who graduated in the seventies had no second language to speak of. Now, in the years...Background Generally speaking. Chinese college graduates in the fifties and sixties took Russian as their second language, and those who graduated in the seventies had no second language to speak of. Now, in the years of our Open Door Policy, they find they have to learn some English and learn it quickly. They try to learn from radio and TV and many take English courses of 4 to 6 months, with varying degree of success. Their chief stumbling blocks展开更多
This article deals with the reflective function of the differential systems. The results are applied to discussion of the existence and stability of the periodic solutions of these systems.
In order to establish the sufficient and necessary condition that arbitrarily reliable systems can not be constructed with function elements under interference sources, it is very important to expand set of interferen...In order to establish the sufficient and necessary condition that arbitrarily reliable systems can not be constructed with function elements under interference sources, it is very important to expand set of interference sources with the above property. In this paper, the models of two types of interference sources are raised respectively: interference source possessing real input vectors and constant reliable interference source. We study the reliability of the systems effected by the interference sources, and the lower bound of the reliability is presented. The results show that it is impossible that arbitrarily reliable systems can not be constructed with the elements effected by above interference sources.展开更多
文摘Background Generally speaking. Chinese college graduates in the fifties and sixties took Russian as their second language, and those who graduated in the seventies had no second language to speak of. Now, in the years of our Open Door Policy, they find they have to learn some English and learn it quickly. They try to learn from radio and TV and many take English courses of 4 to 6 months, with varying degree of success. Their chief stumbling blocks
文摘This article deals with the reflective function of the differential systems. The results are applied to discussion of the existence and stability of the periodic solutions of these systems.
基金Tsinghua University Research Foundation(JC2000025)
文摘In order to establish the sufficient and necessary condition that arbitrarily reliable systems can not be constructed with function elements under interference sources, it is very important to expand set of interference sources with the above property. In this paper, the models of two types of interference sources are raised respectively: interference source possessing real input vectors and constant reliable interference source. We study the reliability of the systems effected by the interference sources, and the lower bound of the reliability is presented. The results show that it is impossible that arbitrarily reliable systems can not be constructed with the elements effected by above interference sources.
