<正> This paper focuses on studying a Hojman conserved quantity directly derived from a Lie symmetry fora Birkhoffian system in the event space.The Birkhoffian
<正> Using an excitonic basis, we investigate the intraband polarization, optical absorption spectra, and terahertzemission of semiconductor superlattice with t
<正>This paper is based on the relations between projection Riccati equations and Weierstrass elliptic equation, combined with the Groebner bases in the symboli
<正> Based on the tortuous-expanding path/channel model,a micro-mechanism model for porous media is developed.The proposed model is expressed as a function of t