Electromechanical carbon nanothermometers are devices that work based on the interactions and relative mo- tions of double-walled carbon nanotubes （DWCNTs）. In this paper, the mechanics of carbon nanotubes （CNTs） ...Electromechanical carbon nanothermometers are devices that work based on the interactions and relative mo- tions of double-walled carbon nanotubes （DWCNTs）. In this paper, the mechanics of carbon nanotubes （CNTs） con- stituting two welt-known configurations for nanothermome- ter, namely shuttle configuration and telescope configuration are fully investigated. Lennard-Jones （LJ） potential func- tion along with the continuum approximation is employed to investigate van der Waals （vdW） interactions between the in- teracting entities. Accordingly, semi-analytical expressions in terms of single integrals are obtained for vdW interactions. Acceptance condition and suction energy are studied for the shuttle configuration. In addition, a universal potential en- ergy is presented for the shuttle configuration consisting of two finite CNTs. Also, for the telescope configuration, ex- tensive studies are performed on the distributions of potential energy and interaction force for various radii and lengths of CNTs. It is found that these geometrical parameters have a considerable effect on the potential energy.展开更多
Spherical bubble oscillations are widely used to model cavitation phenomena in biomedical and naval hydrodynamic systems.During collapse,a sudden increase in surrounding pressure initiates the collapse of a cavitation...Spherical bubble oscillations are widely used to model cavitation phenomena in biomedical and naval hydrodynamic systems.During collapse,a sudden increase in surrounding pressure initiates the collapse of a cavitation bubble,followed by a rebound driven by the high internal gas pressure.While the ideal gas equation of state(EOS)is commonly used to describe the internal pressure and temperature of the bubble,it is limited in its capacity to capture molecular-level effects under highly compressed conditions.In the present study,we employ non-ideal EOS for the gas(the van der Waals EOS and its volume-limited case)to investigate bubble oscillations with a focus on energy redistribution.Bubble oscillation is modeled in two phases:collapse,described by the Keller−Miksis formulation,and rebound,where peak shock pressure is estimated using similitude-based relations.To assess the role of EOS in energy redistribution,we introduce a framework that quantifies energy components in the bubble−liquid system while conserving total energy,tailored to each EOS.Using this framework,we evaluate energy concentration,acoustic radiation,and shock propagation and statistically analyze their dependence on both the driving pressure and the EOS of gas.We statistically derive scaling relations of key bubble dynamics quantities,energy concentration and radiation,and shock pressure using the driving pressure ratio.This work provides a generalizable framework and set of scaling relations for predicting bubble dynamics and energy transfer,with potential applications in evaluating the impacts of cavitation phenomena in complex practical systems.展开更多
Understanding the bending behaviour of a crystal onto a flexible platform is crucial for flexibleelectronics.The Young’s modulus,a measure of how easily a material deforms,plays a critical role inthe coupled deformat...Understanding the bending behaviour of a crystal onto a flexible platform is crucial for flexibleelectronics.The Young’s modulus,a measure of how easily a material deforms,plays a critical role inthe coupled deformation of a crystal on a flexible substrate,as well as the transfer of strain from thesubstrate onto the layer.Here,we report on the bending behaviour of gallium selenide(GaSe),a van derWaals semiconductor with a small Young’s modulus and strain-dependent electronic band structure.A controllable,reproducible uniaxial strain,ϵ,is applied to nanometer-thick GaSe layers via theirbending on a mica substrate.The spectral shiftΔE of the room temperature photoluminescenceemission with increasing strain has a large associated strain coefficientΔE/ϵ.This is accompanied bycoupled electronic and vibrational states under strain-induced resonant excitation conditions,asprobed by Raman spectroscopy.展开更多
文摘Electromechanical carbon nanothermometers are devices that work based on the interactions and relative mo- tions of double-walled carbon nanotubes （DWCNTs）. In this paper, the mechanics of carbon nanotubes （CNTs） con- stituting two welt-known configurations for nanothermome- ter, namely shuttle configuration and telescope configuration are fully investigated. Lennard-Jones （LJ） potential func- tion along with the continuum approximation is employed to investigate van der Waals （vdW） interactions between the in- teracting entities. Accordingly, semi-analytical expressions in terms of single integrals are obtained for vdW interactions. Acceptance condition and suction energy are studied for the shuttle configuration. In addition, a universal potential en- ergy is presented for the shuttle configuration consisting of two finite CNTs. Also, for the telescope configuration, ex- tensive studies are performed on the distributions of potential energy and interaction force for various radii and lengths of CNTs. It is found that these geometrical parameters have a considerable effect on the potential energy.
基金supported by Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.RS-2022-00155966Artificial Intelligence Convergence Innovation Human Resources Development(EwhaWomans University)).
文摘Spherical bubble oscillations are widely used to model cavitation phenomena in biomedical and naval hydrodynamic systems.During collapse,a sudden increase in surrounding pressure initiates the collapse of a cavitation bubble,followed by a rebound driven by the high internal gas pressure.While the ideal gas equation of state(EOS)is commonly used to describe the internal pressure and temperature of the bubble,it is limited in its capacity to capture molecular-level effects under highly compressed conditions.In the present study,we employ non-ideal EOS for the gas(the van der Waals EOS and its volume-limited case)to investigate bubble oscillations with a focus on energy redistribution.Bubble oscillation is modeled in two phases:collapse,described by the Keller−Miksis formulation,and rebound,where peak shock pressure is estimated using similitude-based relations.To assess the role of EOS in energy redistribution,we introduce a framework that quantifies energy components in the bubble−liquid system while conserving total energy,tailored to each EOS.Using this framework,we evaluate energy concentration,acoustic radiation,and shock propagation and statistically analyze their dependence on both the driving pressure and the EOS of gas.We statistically derive scaling relations of key bubble dynamics quantities,energy concentration and radiation,and shock pressure using the driving pressure ratio.This work provides a generalizable framework and set of scaling relations for predicting bubble dynamics and energy transfer,with potential applications in evaluating the impacts of cavitation phenomena in complex practical systems.
基金supported by the Engineering and Physical Sciences Research Council(Grant Nos.EP/T019018/1)。
文摘Understanding the bending behaviour of a crystal onto a flexible platform is crucial for flexibleelectronics.The Young’s modulus,a measure of how easily a material deforms,plays a critical role inthe coupled deformation of a crystal on a flexible substrate,as well as the transfer of strain from thesubstrate onto the layer.Here,we report on the bending behaviour of gallium selenide(GaSe),a van derWaals semiconductor with a small Young’s modulus and strain-dependent electronic band structure.A controllable,reproducible uniaxial strain,ϵ,is applied to nanometer-thick GaSe layers via theirbending on a mica substrate.The spectral shiftΔE of the room temperature photoluminescenceemission with increasing strain has a large associated strain coefficientΔE/ϵ.This is accompanied bycoupled electronic and vibrational states under strain-induced resonant excitation conditions,asprobed by Raman spectroscopy.
