How Does van der Waals Confinement Enhance Phonon Transport?

We study the mechanism of van der Waals(vdW)interactions on phonon transport in atomic scale,which would boost developments in heat management and energy conversion.Commonly,the vdW interactions are regarded as a hindrance in phonon transport.Here we propose that the vdW confinement can enhance phonon transport.Through molecular dynamics simulations,it is realized that the vdW confinement is able to make more than two-fold enhancement on thermal conductivity of both polyethylene single chain and graphene nanoribbon.The quantitative analyses of morphology,local vdW potential energy and dynamical properties are carried out to reveal the underlying physical mechanism.It is found that the confined vdW potential barriers reduce the atomic thermal displacement magnitudes,leading to less phonon scattering and facilitating thermal transport.Our study offers a new strategy to modulate the phonon transport.     

一种新型吡啶鎓盐的合成、结构及光学性质（英文）

通过吡啶盐与3,4-二甲氧基苯甲醛在甲醇中反应,得到高氯酸4-[(3',4'-二甲氧基)苯乙烯基]-N-甲基吡啶鎓,分子式为C_(16)H_(18)ClNO_6。化合物的结构通过红外、元素分析、氢谱、电喷雾质谱和X-单晶衍射仪进行分析与表征。结果表明,该化合物属正交晶系,空间群Pbca,晶胞参数a=13. 5897(11) nm,b=13. 9126(11) nm,c=17. 3485(14) nm,α=90°,β=90°,γ=90°,M_r=355. 76,V=3280. 0(5) nm~3,Z=8,F(000)=1488,D_c=1. 181g/cm~3,μ=0. 265mm~(-1)。同时还研究了该化合物的光学性质。     

一种新型吡啶鎓盐的合成、结构及光学性质

通过吡啶盐与3，4-二甲氧基苯甲醛在甲醇中反应，得到了一种新型的化合物，即4-[（3"，4"-二甲氧基)苯乙烯基]-N-甲基吡啶高氯酸盐，分子式为C16H18ClNO6。化合物的结构通过红外、元素分析、氢谱、电喷雾质谱和X-单晶衍射仪进行分析与表征。结果表明：该化合物属正交晶系，空间群Pbca，晶胞参数a = 13.5897(11) nm, b = 13.9126(11) nm, c = 17.3485(14) nm, α = 90 °, β = 90 °, γ = 90 °, Mr = 355.76, V = 3280.0(5) nm3, Z = 8, F(000) = 1488, Dc = 1.181 g/cm3, μ = 0.265 mm?1。而且还研究了该化合物的光学性质。