In this work, we review the developing progress of two-dimensional terahertz time-domain spectroscopy（THz-TDS） and its diverse applications, including analyzing the polarization of THz radiation from a laser-induced...In this work, we review the developing progress of two-dimensional terahertz time-domain spectroscopy（THz-TDS） and its diverse applications, including analyzing the polarization of THz radiation from a laser-induced plasma source and studying the corresponding physical mechanism, and characterizing the optical properties of crystals, etc.展开更多
Using the axial symmetry results of marker and cell (MAC) method as initial value in this paper, two numerical calculating methods are presented for the late wavemaking response induced by explosion in harbour. One of...Using the axial symmetry results of marker and cell (MAC) method as initial value in this paper, two numerical calculating methods are presented for the late wavemaking response induced by explosion in harbour. One of the methods is the superposition method of the vibration mode based on fluid slosh in container. Another one is the joining method of the MAC results with the shallow wave theory calculation in time domain. As a practical example, it is conducted to the numerical calculation about 1000 ton TNT equivalent explosion within touch of water surface. The results show that it can be rationally described with the methods to the wavemaking progress and character. The numerical results are identical with the observed scene on the spot experiment. The methods are simple and applicable in the engineering design.展开更多
The electromagnetically induced reflection(EIR)effect of graphene metamaterials has been investigated by finite difference time domain(FDTD)method.In this study,a metamaterial sandwich structure composed of silica(SiO...The electromagnetically induced reflection(EIR)effect of graphene metamaterials has been investigated by finite difference time domain(FDTD)method.In this study,a metamaterial sandwich structure composed of silica(SiO2),gold and graphene on terahertz band is designed.By changing the width of the two ribbons of graphene length and the incident angle of electromagnetic wave,the EIR effect of the structure is discussed,and it can be found that SiO2 is a kind of excellent dielectric material.The simulation results show that graphene metamaterial is not sensitive to polarized incident electromagnetic wave.Therefore,such EIR phenomena as insensitive polarization and large incident angle can be applied to optical communication filters and terahertz devices.展开更多
The wind-induced responses of a large-scale membrane structure, Expo Boulevard, are evaluated in this study. To obtain the wind pressure distribution on the roof surface, a wind tunnel test is performed. A brief analy...The wind-induced responses of a large-scale membrane structure, Expo Boulevard, are evaluated in this study. To obtain the wind pressure distribution on the roof surface, a wind tunnel test is performed. A brief analysis of wind pressure on the membrane roof is conducted first and then an analysis of the wind-induced responses of the structure is carried out using a numerical integral method in the time domain. In the process of calculation, the geometrical nonlinearity is taken into account. Results indicate that mean, RSM and peak values of the structure responses increase nonlinearly while the approaching flow velocity increases. Strong nonlinear characteristics are observed in the displacement responses, whereas the responses of nodal stress and cable axial force show minimal nonlinear properties when the membrane structure is subjected to wind loads. Different values of the damping ratio only have a minimal impact on the RSM response of the structure because the background component is a dominant part of the total dynamic response and the resonant component is too small. As the damping ratio increases from 0.02 to 0.05, the RMS responses of vertical displacement, nodal stress and cable axial force decrease by 8.1%, 6.7% and 17.9%, respectively. Since the mean component plays a significant role in the wind-induced response, the values of the gust response factor are not high for Expo Boulevard.展开更多
基金supported by the National Basic Research Program of China under Grant No.2014CB339802,No.2011CB808100the National Natural Science Foundation of China under Grant No.11174156
文摘In this work, we review the developing progress of two-dimensional terahertz time-domain spectroscopy（THz-TDS） and its diverse applications, including analyzing the polarization of THz radiation from a laser-induced plasma source and studying the corresponding physical mechanism, and characterizing the optical properties of crystals, etc.
基金Subsidized subject financially supported by the National Natural Science Foundation of China
文摘Using the axial symmetry results of marker and cell (MAC) method as initial value in this paper, two numerical calculating methods are presented for the late wavemaking response induced by explosion in harbour. One of the methods is the superposition method of the vibration mode based on fluid slosh in container. Another one is the joining method of the MAC results with the shallow wave theory calculation in time domain. As a practical example, it is conducted to the numerical calculation about 1000 ton TNT equivalent explosion within touch of water surface. The results show that it can be rationally described with the methods to the wavemaking progress and character. The numerical results are identical with the observed scene on the spot experiment. The methods are simple and applicable in the engineering design.
基金Research Project of Anhui Province Education Department(No.KJ2020A0684)Innovation and Entrepreneurship Training Program for College Students(Nos.S201910375072,201910375050,201910375052,202010375030)。
文摘The electromagnetically induced reflection(EIR)effect of graphene metamaterials has been investigated by finite difference time domain(FDTD)method.In this study,a metamaterial sandwich structure composed of silica(SiO2),gold and graphene on terahertz band is designed.By changing the width of the two ribbons of graphene length and the incident angle of electromagnetic wave,the EIR effect of the structure is discussed,and it can be found that SiO2 is a kind of excellent dielectric material.The simulation results show that graphene metamaterial is not sensitive to polarized incident electromagnetic wave.Therefore,such EIR phenomena as insensitive polarization and large incident angle can be applied to optical communication filters and terahertz devices.
基金National Natural Science Foundation under Grant No. 51278368the Fundamental Research Funds for the Central Universities
文摘The wind-induced responses of a large-scale membrane structure, Expo Boulevard, are evaluated in this study. To obtain the wind pressure distribution on the roof surface, a wind tunnel test is performed. A brief analysis of wind pressure on the membrane roof is conducted first and then an analysis of the wind-induced responses of the structure is carried out using a numerical integral method in the time domain. In the process of calculation, the geometrical nonlinearity is taken into account. Results indicate that mean, RSM and peak values of the structure responses increase nonlinearly while the approaching flow velocity increases. Strong nonlinear characteristics are observed in the displacement responses, whereas the responses of nodal stress and cable axial force show minimal nonlinear properties when the membrane structure is subjected to wind loads. Different values of the damping ratio only have a minimal impact on the RSM response of the structure because the background component is a dominant part of the total dynamic response and the resonant component is too small. As the damping ratio increases from 0.02 to 0.05, the RMS responses of vertical displacement, nodal stress and cable axial force decrease by 8.1%, 6.7% and 17.9%, respectively. Since the mean component plays a significant role in the wind-induced response, the values of the gust response factor are not high for Expo Boulevard.
