The spectral character of X-ray emitted from laser-irradiated gold disk is studied by using the one-dimensional non-LTE multigroup radiation transport hydrodynamics code RDMG. The applicability of the “three-temperat...The spectral character of X-ray emitted from laser-irradiated gold disk is studied by using the one-dimensional non-LTE multigroup radiation transport hydrodynamics code RDMG. The applicability of the “three-temperature” model in which the radiation is described with thermal conduction approximation is checked. The simulation results show that the X-ray emitted from the laser-produced gold plasma is in non-LTE, and that the atom model has significant effect on the structure of X-ray spectrum. However, the plasma states, laser absorption efficiency and X-ray conversion efficiency, which are calculated with the “three-temperature” model, are almost the same as those with non-LTE multigroup radiation transport model. This fact indicates that the “three-temperature” model can be used to study plasma states and the energy distributions produced by a laser-irradiated high-Z target. This is meaningful to the 2-D or 3-D simulation.展开更多
The advancement of flexible electronics demands improved components,necessitating heat dissipation membranes(HDMs)to exhibit high thermal conductivity while maintaining structural integrity and performance stability e...The advancement of flexible electronics demands improved components,necessitating heat dissipation membranes(HDMs)to exhibit high thermal conductivity while maintaining structural integrity and performance stability even after extensive deformation.Herein,we have devised a laser-modulated reduction technique for graphene oxide(GO),enabling the fabrication of high-quality,large-scale,lowdefect graphene,which yields high-performance HDMs after orderly deposition.The work underscores the crucial role of the laser wavelength and dispersion liquid's coupling intensity in influencing the morphology and properties of graphene.Optimal coupling effect and energy conversion are realized when a laser of 1064 nm wavelength irradiates a triethylene glycol(TEG)/N,N-Dimethylformamide(DMF)dispersion.This unique synergy generates high transient energy,which facilitates the deprotonation process and ensures a swift,comprehensive GO reduction.In contrast to conventional water-based laser reduction methods,the accelerated reaction magnifies the size of the graphene sheets by mitigating the ablation effect.After membrane construction with an ordered structure,the corresponding membrane exhibits a high thermal conductivity of 1632 W m^(-1)K^(-1),requiring only~1/10 of the total preparation time required by other reported methods.Remarkably,the resulting HDM demonstrates superior resilience against creasing and folding,maintaining excellent smoothness and negligible reduction in thermal conductivity after violent rubbing.The combination of exceptional flexibility and thermal conductivity in HDMs paves the way for long-term practical use in the flexible electronics industry.展开更多
It has been a challenge to fully understand the structural characteristics of laser-irradiation induced amorphous(L-a) Ge2Sb2Te5(GST) alloy due to the difficulties of collecting diffraction data from high purity speci...It has been a challenge to fully understand the structural characteristics of laser-irradiation induced amorphous(L-a) Ge2Sb2Te5(GST) alloy due to the difficulties of collecting diffraction data from high purity specimens. In this paper,by fabricating GST thin films on different substrates,we exhibit an effective way of preparing L-a GST dots in submicron scale on various types of specially designed transmission electron microscope(TEM) grids. The structural characteristics of L-a GST in the form of pair distribution functions(PDF) can be achieved on single dots of L-a GST via selected area electron diffraction(SAED) . This general approach would be convenient for precisely producing laser-irradiation induced materials in submicron scale for structural investigation.展开更多
文摘The spectral character of X-ray emitted from laser-irradiated gold disk is studied by using the one-dimensional non-LTE multigroup radiation transport hydrodynamics code RDMG. The applicability of the “three-temperature” model in which the radiation is described with thermal conduction approximation is checked. The simulation results show that the X-ray emitted from the laser-produced gold plasma is in non-LTE, and that the atom model has significant effect on the structure of X-ray spectrum. However, the plasma states, laser absorption efficiency and X-ray conversion efficiency, which are calculated with the “three-temperature” model, are almost the same as those with non-LTE multigroup radiation transport model. This fact indicates that the “three-temperature” model can be used to study plasma states and the energy distributions produced by a laser-irradiated high-Z target. This is meaningful to the 2-D or 3-D simulation.
基金supported by the National Science Foundation of Jiangsu Province(BK20210861)the National Natural Science Foundation of China(62101374)the open research fund of Key Laboratory of MEMS of Ministry of Education,Southeast University。
文摘The advancement of flexible electronics demands improved components,necessitating heat dissipation membranes(HDMs)to exhibit high thermal conductivity while maintaining structural integrity and performance stability even after extensive deformation.Herein,we have devised a laser-modulated reduction technique for graphene oxide(GO),enabling the fabrication of high-quality,large-scale,lowdefect graphene,which yields high-performance HDMs after orderly deposition.The work underscores the crucial role of the laser wavelength and dispersion liquid's coupling intensity in influencing the morphology and properties of graphene.Optimal coupling effect and energy conversion are realized when a laser of 1064 nm wavelength irradiates a triethylene glycol(TEG)/N,N-Dimethylformamide(DMF)dispersion.This unique synergy generates high transient energy,which facilitates the deprotonation process and ensures a swift,comprehensive GO reduction.In contrast to conventional water-based laser reduction methods,the accelerated reaction magnifies the size of the graphene sheets by mitigating the ablation effect.After membrane construction with an ordered structure,the corresponding membrane exhibits a high thermal conductivity of 1632 W m^(-1)K^(-1),requiring only~1/10 of the total preparation time required by other reported methods.Remarkably,the resulting HDM demonstrates superior resilience against creasing and folding,maintaining excellent smoothness and negligible reduction in thermal conductivity after violent rubbing.The combination of exceptional flexibility and thermal conductivity in HDMs paves the way for long-term practical use in the flexible electronics industry.
基金supported by the National Basic Research Program of China (Grant Nos.2007CB935400 and 2009CB623700)
文摘It has been a challenge to fully understand the structural characteristics of laser-irradiation induced amorphous(L-a) Ge2Sb2Te5(GST) alloy due to the difficulties of collecting diffraction data from high purity specimens. In this paper,by fabricating GST thin films on different substrates,we exhibit an effective way of preparing L-a GST dots in submicron scale on various types of specially designed transmission electron microscope(TEM) grids. The structural characteristics of L-a GST in the form of pair distribution functions(PDF) can be achieved on single dots of L-a GST via selected area electron diffraction(SAED) . This general approach would be convenient for precisely producing laser-irradiation induced materials in submicron scale for structural investigation.
