This work uses the molecular dynamics approach to study the effects of functionalization of carbon nanotubes(CNTs)on the mechanical properties of Cu64Zr36 metallic glass(MG).Three types of functional groups,carboxylic...This work uses the molecular dynamics approach to study the effects of functionalization of carbon nanotubes(CNTs)on the mechanical properties of Cu64Zr36 metallic glass(MG).Three types of functional groups,carboxylic,vinyl and ester were used.The effect of CNT volume fraction(Vf)and the number of functional groups attached to CNT,on the mechanical properties and thermal conductivity of CNT-MG composites was analysed using Biovia Materials Studio.At lower values of Vf(from 0 to 5%),the percentage increase in Young’s modulus was approximately 66%.As the value of Vf was increased further(from 5 to 12%),the rate of increase in Young’s modulus was reduced to 16%.The thermal conductivity was found to increase from 1.52 W/mK at Vf?0%to 5.88 W/mK at Vf?12%,thus giving an increase of approximately 286%.Functionalization of SWCNT reduced the thermal conductivity of the SWCNT-MG composites.展开更多
Porous materials can be found in a variety of geophysical and engineering applications.The existence of thermal contact resistance at the interface between bilayered saturated porous strata would result in a significa...Porous materials can be found in a variety of geophysical and engineering applications.The existence of thermal contact resistance at the interface between bilayered saturated porous strata would result in a significant temperature difference at the interface.An attempt is made to study the thermo-hydro-mechanical coupling dynamic response of bilayered saturated porous strata with thermal contact resistance and elastic wave impedance.The corresponding analytical solutions for the dynamic response of bilayered saturated porous strata under a harmonic thermal load are derived by the operator decomposition method,and their rationality is verified by comparing them with existing solutions.The influences of thermal contact resistance,thermal conductivity ratio,and porosity ratio on the dynamic response of bilayered saturated porous strata are systematically investigated.Outcomes disclose that with the increase of thermal contact resistance,the displacement,pore water pressure and stress decrease gradually,and the temperature jump at the interface between two saturated porous strata increases.展开更多
随着特高压输电技术的快速发展和大容量电力传输需求的不断增加,绝缘纸在极端环境下的电气性能、机械强度及热稳定性面临着更为严峻的挑战。该文提出纳米SiO_(2)粒子掺杂与等离子体氟化协同改性策略,系统研究协同改性前后绝缘纸的电气...随着特高压输电技术的快速发展和大容量电力传输需求的不断增加,绝缘纸在极端环境下的电气性能、机械强度及热稳定性面临着更为严峻的挑战。该文提出纳米SiO_(2)粒子掺杂与等离子体氟化协同改性策略,系统研究协同改性前后绝缘纸的电气性能、机械性能、疏水性能及热老化性能的演变规律,通过扫描电子显微镜(scanning electron microscope,SEM)和能量色散X射线光谱仪(energy dispersive spectrometer,EDS)表征氟化处理后绝缘纸表面形貌与元素分布变化。基于分子动力学模拟,揭示纳米粒子掺杂和含氟基团介质的协同增强机制。结果表明:纳米SiO_(2)粒子掺杂协同等离子体氟化改性可有效限制载流子的运动,显著提升了绝缘纸的绝缘性能。与未改性相比,绝缘纸的击穿场强和体积电阻率分别提高109.2%和134.9%。协同改性处理后,绝缘纸表面接枝了大量含氟基团,显著提升其表面疏水性;同时,含氟基团与纳米SiO_(2)间形成的氢键强化了纳米SiO_(2)与绝缘纸的桥接作用,进而可有效提升绝缘纸的热老化性能。展开更多
文摘This work uses the molecular dynamics approach to study the effects of functionalization of carbon nanotubes(CNTs)on the mechanical properties of Cu64Zr36 metallic glass(MG).Three types of functional groups,carboxylic,vinyl and ester were used.The effect of CNT volume fraction(Vf)and the number of functional groups attached to CNT,on the mechanical properties and thermal conductivity of CNT-MG composites was analysed using Biovia Materials Studio.At lower values of Vf(from 0 to 5%),the percentage increase in Young’s modulus was approximately 66%.As the value of Vf was increased further(from 5 to 12%),the rate of increase in Young’s modulus was reduced to 16%.The thermal conductivity was found to increase from 1.52 W/mK at Vf?0%to 5.88 W/mK at Vf?12%,thus giving an increase of approximately 286%.Functionalization of SWCNT reduced the thermal conductivity of the SWCNT-MG composites.
基金Projects(52108347,52178371)supported by the National Natural Science Foundation of ChinaProject(LQ22E080010)supported by the Exploring Youth Project of Zhejiang Natural Science Foundation,China。
文摘Porous materials can be found in a variety of geophysical and engineering applications.The existence of thermal contact resistance at the interface between bilayered saturated porous strata would result in a significant temperature difference at the interface.An attempt is made to study the thermo-hydro-mechanical coupling dynamic response of bilayered saturated porous strata with thermal contact resistance and elastic wave impedance.The corresponding analytical solutions for the dynamic response of bilayered saturated porous strata under a harmonic thermal load are derived by the operator decomposition method,and their rationality is verified by comparing them with existing solutions.The influences of thermal contact resistance,thermal conductivity ratio,and porosity ratio on the dynamic response of bilayered saturated porous strata are systematically investigated.Outcomes disclose that with the increase of thermal contact resistance,the displacement,pore water pressure and stress decrease gradually,and the temperature jump at the interface between two saturated porous strata increases.
文摘随着特高压输电技术的快速发展和大容量电力传输需求的不断增加,绝缘纸在极端环境下的电气性能、机械强度及热稳定性面临着更为严峻的挑战。该文提出纳米SiO_(2)粒子掺杂与等离子体氟化协同改性策略,系统研究协同改性前后绝缘纸的电气性能、机械性能、疏水性能及热老化性能的演变规律,通过扫描电子显微镜(scanning electron microscope,SEM)和能量色散X射线光谱仪(energy dispersive spectrometer,EDS)表征氟化处理后绝缘纸表面形貌与元素分布变化。基于分子动力学模拟,揭示纳米粒子掺杂和含氟基团介质的协同增强机制。结果表明:纳米SiO_(2)粒子掺杂协同等离子体氟化改性可有效限制载流子的运动,显著提升了绝缘纸的绝缘性能。与未改性相比,绝缘纸的击穿场强和体积电阻率分别提高109.2%和134.9%。协同改性处理后,绝缘纸表面接枝了大量含氟基团,显著提升其表面疏水性;同时,含氟基团与纳米SiO_(2)间形成的氢键强化了纳米SiO_(2)与绝缘纸的桥接作用,进而可有效提升绝缘纸的热老化性能。
