College of Electrical Engineering and Automation, Henan Polytechnic University, Jiaozuo 454000, China;
College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
College of Electrical Engineering, Zhejiang University, Hangzhou 310027, China;
chaos; passive control; the Newton-Leipnik equation attractor;