Anderson localization of phonons is a kind of phonon wave effect,which has been proved to occur in many structures with disorders.In this work,we introduced aperiodicity to boron nitride/carbon nanotube superlattices(...Anderson localization of phonons is a kind of phonon wave effect,which has been proved to occur in many structures with disorders.In this work,we introduced aperiodicity to boron nitride/carbon nanotube superlattices(BN/C NT SLs),and used molecular dynamics to calculate the thermal conductivity and the phonon transmission spectrum of the models.The existence of phonon Anderson localization was proved in this quasi one-dimensional structure by analyzing the phonon transmission spectra.Moreover,we introduced interfacial mixing to the aperiodic BN/C NT SLs and found that the coexistence of the two disorder entities(aperiodicity and interfacial mixing)can further decrease the thermal conductivity.In addition,we also showed that anharmonicity can destroy phonon localization at high temperatures.This work provides a reference for designing thermoelectric materials with low thermal conductivity by taking advantage of phonon localization.展开更多
In this paper, we consider the continuous parabolic Anderson model with a logcorrelated Gaussian field, and obtain the precise quenched long-time asymptotics and spatial asymptotics. To overcome the difficulties arisi...In this paper, we consider the continuous parabolic Anderson model with a logcorrelated Gaussian field, and obtain the precise quenched long-time asymptotics and spatial asymptotics. To overcome the difficulties arising from the log-correlated Gaussian field in the proof of the lower bound of the spatial asymptotics, we first establish the relation between quenched long-time asymptotics and spatial asymptotics, and then get the lower bound of the spatial asymptotics through the lower bound of the quenched long-time asymptotics.展开更多
Based on the algebraic equation of motion(AEOM)approach,we have studied the single-impurity Anderson model by analytically solving the AEOM of the f-electron one-particle Green function in the Kondo limit.The related ...Based on the algebraic equation of motion(AEOM)approach,we have studied the single-impurity Anderson model by analytically solving the AEOM of the f-electron one-particle Green function in the Kondo limit.The related spectral function satisfies the sum rule and shows that there is a well-known three-peak structure at zero temperature.In the low energy limit,we obtain the analytical formula of the Kondo temperature that is the same as the exact solution in form except for a prefactor.We also show that the shape of the Kondo resonance is the Lorentzian form and the corresponding weight is proportional to the spin-flip correlation function.展开更多
A new kind of Anderson type chromium molybdates containing the rare earth elements are synthesized, which have the general molecular formula of (NH4)6[CrMo5Ln(OH2)2O24H6]·xH2O (Ln=La,Ce,Pr,Nd,Sm,Gd and Yb). The c...A new kind of Anderson type chromium molybdates containing the rare earth elements are synthesized, which have the general molecular formula of (NH4)6[CrMo5Ln(OH2)2O24H6]·xH2O (Ln=La,Ce,Pr,Nd,Sm,Gd and Yb). The components of theseheteropoly complexes are determined by chemical elemental analysis, ICP and TG DTA. And IR, UV, ESR,XPS and 1H NMR are also applied to characterize the complexes as well. The results indicate that the structures of these complexes are Anderson B type and the rare earth elements are in the inner sphere of the heteropoly salts. The thermal stabilities of these complexes studied by TG DTA show that the range of pyrolysis temperature is between 490℃and 500℃.展开更多
文摘Anderson localization of phonons is a kind of phonon wave effect,which has been proved to occur in many structures with disorders.In this work,we introduced aperiodicity to boron nitride/carbon nanotube superlattices(BN/C NT SLs),and used molecular dynamics to calculate the thermal conductivity and the phonon transmission spectrum of the models.The existence of phonon Anderson localization was proved in this quasi one-dimensional structure by analyzing the phonon transmission spectra.Moreover,we introduced interfacial mixing to the aperiodic BN/C NT SLs and found that the coexistence of the two disorder entities(aperiodicity and interfacial mixing)can further decrease the thermal conductivity.In addition,we also showed that anharmonicity can destroy phonon localization at high temperatures.This work provides a reference for designing thermoelectric materials with low thermal conductivity by taking advantage of phonon localization.
基金supported by the National Natural Science Foundation of China (12201282)the Institute of Meteorological Big Data-Digital Fujian and the Fujian Key Laboratory of Data Science and Statistics (2020L0705)the Education Department of Fujian Province (JAT200325)。
文摘In this paper, we consider the continuous parabolic Anderson model with a logcorrelated Gaussian field, and obtain the precise quenched long-time asymptotics and spatial asymptotics. To overcome the difficulties arising from the log-correlated Gaussian field in the proof of the lower bound of the spatial asymptotics, we first establish the relation between quenched long-time asymptotics and spatial asymptotics, and then get the lower bound of the spatial asymptotics through the lower bound of the quenched long-time asymptotics.
基金Project supported by the National Natural Science Foundation of China(Grant No.11974420)。
文摘Based on the algebraic equation of motion(AEOM)approach,we have studied the single-impurity Anderson model by analytically solving the AEOM of the f-electron one-particle Green function in the Kondo limit.The related spectral function satisfies the sum rule and shows that there is a well-known three-peak structure at zero temperature.In the low energy limit,we obtain the analytical formula of the Kondo temperature that is the same as the exact solution in form except for a prefactor.We also show that the shape of the Kondo resonance is the Lorentzian form and the corresponding weight is proportional to the spin-flip correlation function.
文摘A new kind of Anderson type chromium molybdates containing the rare earth elements are synthesized, which have the general molecular formula of (NH4)6[CrMo5Ln(OH2)2O24H6]·xH2O (Ln=La,Ce,Pr,Nd,Sm,Gd and Yb). The components of theseheteropoly complexes are determined by chemical elemental analysis, ICP and TG DTA. And IR, UV, ESR,XPS and 1H NMR are also applied to characterize the complexes as well. The results indicate that the structures of these complexes are Anderson B type and the rare earth elements are in the inner sphere of the heteropoly salts. The thermal stabilities of these complexes studied by TG DTA show that the range of pyrolysis temperature is between 490℃and 500℃.
