In this study, author investigated the spectral response of EM （electromagnetic） energy absorption in a colloidal system of Fe3O4 nanoparticles with an average size of 9.50 nm immersed in a 2% aqueous solution of S...In this study, author investigated the spectral response of EM （electromagnetic） energy absorption in a colloidal system of Fe3O4 nanoparticles with an average size of 9.50 nm immersed in a 2% aqueous solution of SDS （sodium dodeci[ sulfate）. The temperature of the nanoparticles and the SDS solution was evaluated by a novel method based on measuring the Q-factor （quality-factor） of a resonant circuit. The Q-factor of the investigated system as a function of the frequency of the EM field was obtained. The nanoparticles-SDS liquid system exhibited a resonance-like behavior of the absorption, where the resonance frequency was about 170 MHz, and the absorption rise up to the resonance frequency was rather slow. The observed absorption of EM energy was accompanied by a small temperature increasing of the system. Measurements of the ESR （electron spin resonance） spectrum of the Fe3O4 nanoparticles have presented a slightly asymmetric singlet with the proportionality factor g = 2 and a line-width of the magnetic field strength △H = 0.1 mT. It was shown that the observed absorption spectrum corresponds to paramagnetic behavior of the investigated nanoparticles.展开更多
In this article,under the assumption of weak anisotropy and weak attenuation, we present approximate solutions of anisotropic complex velocities and quality-factors for Kelvin visco-elastic transverse isotropy（KEL-VT...In this article,under the assumption of weak anisotropy and weak attenuation, we present approximate solutions of anisotropic complex velocities and quality-factors for Kelvin visco-elastic transverse isotropy（KEL-VTI） media,based on the complex physical parameter matrix.Also,combined with the KEL-VTI media model,the propagation characteristics of the qP-,qS V-,and qSH-wave phases and energies are discussed.Further, we build a typical KEL-VTI media model of the Huainan coal mine to model the wave propagation.The numerical simulation results show that the PP- and PSV-wave theoretical wave-fields are close to the wave-fields of three-component P- and converted-waves acquired in the work area.This result proves that the KEL-VTI media model gives a good approximation to this typical coalfield seismic-geologic conditions and is helpful to the study of attenuation compensation of multi-component seismic data.展开更多
The phenomenon of induced transparency,characterized by a high quality(Q)factor,holds significant importance in the fields of high-precision sensing,energy storage and wave manipulation.Conventional transparency syste...The phenomenon of induced transparency,characterized by a high quality(Q)factor,holds significant importance in the fields of high-precision sensing,energy storage and wave manipulation.Conventional transparency systems are often constrained by the limited experimentally accessible parameter space and the lack of independent control over intrinsic parameters,thereby hindering advanced research on high-Q effects.Here we propose a virtualized coupled-oscillator system that enables reconfigurable induced transparency in the reflection spectrum.By virtually incorporating a pair of coupled oscillators into an individual acoustic meta-atom,we achieve the manipulation of induced transparency in a decoupled,wide-ranging,and elaborate manner.Exploiting the diverse evolutions across the intrinsic parameter space,we show experimentally a counter-intuitive increase in the Q-factor of the transparency window,which is attributed to the enhanced dissipation of the bright oscillator.Meanwhile,a constant group delay at the center frequency is observed accompanying this evolution.Our work demonstrates an intriguing platform as well as a novel strategy to engineer high-Q induced transparency phenomenon,and paves the way towards applications in programmable acoustic sensors,filters and slow-wave devices.展开更多
文摘In this study, author investigated the spectral response of EM （electromagnetic） energy absorption in a colloidal system of Fe3O4 nanoparticles with an average size of 9.50 nm immersed in a 2% aqueous solution of SDS （sodium dodeci[ sulfate）. The temperature of the nanoparticles and the SDS solution was evaluated by a novel method based on measuring the Q-factor （quality-factor） of a resonant circuit. The Q-factor of the investigated system as a function of the frequency of the EM field was obtained. The nanoparticles-SDS liquid system exhibited a resonance-like behavior of the absorption, where the resonance frequency was about 170 MHz, and the absorption rise up to the resonance frequency was rather slow. The observed absorption of EM energy was accompanied by a small temperature increasing of the system. Measurements of the ESR （electron spin resonance） spectrum of the Fe3O4 nanoparticles have presented a slightly asymmetric singlet with the proportionality factor g = 2 and a line-width of the magnetic field strength △H = 0.1 mT. It was shown that the observed absorption spectrum corresponds to paramagnetic behavior of the investigated nanoparticles.
基金the National 973 Program(Grant No.2006CB202207)Special Fund(Grant Nos. 2008ZX05035-001-003,2008ZX05035-003-004,and 2008ZX05008-006-004).
文摘In this article,under the assumption of weak anisotropy and weak attenuation, we present approximate solutions of anisotropic complex velocities and quality-factors for Kelvin visco-elastic transverse isotropy（KEL-VTI） media,based on the complex physical parameter matrix.Also,combined with the KEL-VTI media model,the propagation characteristics of the qP-,qS V-,and qSH-wave phases and energies are discussed.Further, we build a typical KEL-VTI media model of the Huainan coal mine to model the wave propagation.The numerical simulation results show that the PP- and PSV-wave theoretical wave-fields are close to the wave-fields of three-component P- and converted-waves acquired in the work area.This result proves that the KEL-VTI media model gives a good approximation to this typical coalfield seismic-geologic conditions and is helpful to the study of attenuation compensation of multi-component seismic data.
基金supported by the National Natural Science Foundation of China(Grant Nos.12104480 and 12104383)the National Natural Science Foundation of Beijing(Grant No.L233037)the IACAS Frontier Exploration Project(Grant No.QYTS202110)。
文摘The phenomenon of induced transparency,characterized by a high quality(Q)factor,holds significant importance in the fields of high-precision sensing,energy storage and wave manipulation.Conventional transparency systems are often constrained by the limited experimentally accessible parameter space and the lack of independent control over intrinsic parameters,thereby hindering advanced research on high-Q effects.Here we propose a virtualized coupled-oscillator system that enables reconfigurable induced transparency in the reflection spectrum.By virtually incorporating a pair of coupled oscillators into an individual acoustic meta-atom,we achieve the manipulation of induced transparency in a decoupled,wide-ranging,and elaborate manner.Exploiting the diverse evolutions across the intrinsic parameter space,we show experimentally a counter-intuitive increase in the Q-factor of the transparency window,which is attributed to the enhanced dissipation of the bright oscillator.Meanwhile,a constant group delay at the center frequency is observed accompanying this evolution.Our work demonstrates an intriguing platform as well as a novel strategy to engineer high-Q induced transparency phenomenon,and paves the way towards applications in programmable acoustic sensors,filters and slow-wave devices.
