【摘要】 考虑在渗流阈值附近弱非线性正常导体与绝缘体所构成的无规网络在任意d维空间的非线性渡越行为.系统由正常导体浓度为p,且满足弱非线性电流密度(J)电场(E)关系:J=σ1E+χ1|E|βE和浓度为1-p的绝缘体(σ2=0)构成.在略高于正常导体渗流阈值pc时,复合系统的有效响应可表示为〈J〉=σe〈E〉+χe|〈E〉|β〈E〉,当线性响应与非线性响应两者可相互比较时,此时的电流密度和电场强度被分别称为渡越电流密度|Jc|和渡越电场|Ec|,且发现略高于渗流阈值pc时具有幂指数关系:|Ec|～(p-pc)M(β)和|Jc|～(p-pc)N(β).利用电极结点键与相对涨落关系的方法详细地研究了渡越指数M(β),N(β)随非线性指数β及维数d的变化规律更多还原

【Abstract】 The effective nonlinear response in d \|dimensional percolating weakly nonlinear normal conductor( N ) insulator( I) random network near the percolation threshold is studied.The network is composed of two kinds of elements:the normal conductor ( N ) which has a concentration p and obeys weakly nonlinear current density (J) electric field (E) characristics (J=σ 1E+χ 1｜E｜ βE),and the insulator ( I ) which has a concentration ( 1-p ) and σ 2=0. Above the percolation threshold p c of the normal conductors,the effective response of the network can be represented by更多还原