Influence of lattice constant on transmission,negative refractive index (NRI) and FOM of left-handed materials was studied.It shows that lower-order transmission peak of left-handed materials increases unusually with lattice constant decreased,due to impedance matching.And center frequency of NRI of left-handed materials is blue-shifted with decreased lattice constant,which is consistent with theoretical results.As lattice constant decreased to a certain value,perfect impedance matching is achieved which leads to higher FOM.

Suppression of spiral waves and spatiotemporal chaos in cardiac tissues described by LuoRudy 91 model are studied.We suggest a control strategy which applys calcium channel agonist to enlarge maximum conductivity of calcium current,and applys potassium channel blocker to reduce maximum conductivity of potassium current,for suppression of spiral waves and spatiotemporal chaos.It shows that the method can effectively suppress spiral waves and spatiotemporal chaos even if there exist defects without function of diffusion in a medium.The control mechanism is analyzed.