中文摘要：

在三维紧束缚模型下,采用传递矩阵的方法研究了不同界面耦合对DNA分子电荷输运性质的影响.结果表明：界面耦合理想时,透射率和电子定域长度都很大,分子呈现出良好的导电性;反之,透射率和电子定域长度减小,分子呈现出较差的导电性.当分子与金属电极之间理想耦合时,从伏安特性上可以看出,poly（dG）-poly（dC）DNA分子的开启电压小于poly（dA）-poly（dT）DNA分子的开启电压,并且在相同的偏压下前者的电流值要大于后者.因此,poly（dG）-poly（dC）DNA分子的导电性优于poly（dA）-poly（dT）DNA分子的导电性.

英文摘要：

Using the three-dimensional tight-binding model and the matrix transfer method,effects of interfacial couplings on the charge transport properties of DNA molecule have been studied.The results indicate that when the interfacial couplings are ideal,both transmission coefficient and localization length of electrons are larger,the molecule shows higher conductivity,while the case is the contrary when the interfacial couplings are unideal.When the molecule and the metallic electrodes couple ideally,through voltage-current characteristic,it is found that the onset voltage of poly（dG）-poly（dC） DNA is lower than that for the poly（dA）-poly（dT） counterpart,and the current of the former is larger than that of the latter under the same bias voltage,so the conductivity of poly（dG）-poly（dC） DNA is higher than that of the poly（dA）-poly（dT） counterpart.