A novel metasurface antenna consisting of 5×5 rectangular patch elements is presented.Thestructure with and without the central element are both analyzed by the Characteristic Mode Theory(CMT).The developed mutua...A novel metasurface antenna consisting of 5×5 rectangular patch elements is presented.Thestructure with and without the central element are both analyzed by the Characteristic Mode Theory(CMT).The developed mutually orthogonal principal modes of the optimized periodic patch structure areexcited by a center-feed dipole.A differential feeding network is employed to realize impedance matching.Prototype with profile height of 0.07λ_(0)(λ_(0)is the wavelength in free space at the lowest operatingfrequency)is fabricated and assembled to verify the simulation results.The measured results show that thereflectance coefficient of proposed matesurface antenna is less than-10 dB in the whole operating bandrange from 4.2 GHz to 5.5 GHz,a relative bandwidth of 26.8%is achieved,and the maximummeasured realized gain is more than 9 dBi with a maximum radiation efficiency of 90%.The designprovides a guideline on the application of characteristic modes(CMs)to radiation problems.展开更多
The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-m...The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-mechanical problem for saturated porous deep-sea sediments subject to the vibration of the mining vehicle is investigated.Based on the Green-Lindsay(G-L)generalized thermoelastic theory and Darcy’s law,the model of thermo-hydro-mechanical dynamic responses for saturated porous deep-sea sediments under the vibration of the mining vehicle is established.We obtain the analytical solutions of non-dimensional vertical displacement,excess pore water pressure,vertical stress,temperature,and change in the volume fraction field with the normal mode analysis method,and depict them graphically.The normal mode analysis method uses the canonical coordinate transformation to solve the equation,which can quickly decouple the equation by ignoring the modal coupling effect on the basis of the canonical mode.The results indicate that the vibration frequency has obvious influence on the vertical displacement,excess pore water pressure,vertical stress,and change in volume fraction field.The loading amplitude has a great effect on the physical quantities in the foundation,and the changes of the physical quantities increase with the increase in loading amplitude.展开更多
From the view of the physical model,structure and function characteristics,the material basis and clinical application of Yin-Yang theory,analysing and thinking combined with modern medical theory,this paper finds tha...From the view of the physical model,structure and function characteristics,the material basis and clinical application of Yin-Yang theory,analysing and thinking combined with modern medical theory,this paper finds that as one of the most basic and important theory of traditional Chinese medicine(TCM),Yin-Yang theory reveals the understanding of human physiology in TCM,which has many consensuses with modern medicine,so it is worth studying further.展开更多
文摘A novel metasurface antenna consisting of 5×5 rectangular patch elements is presented.Thestructure with and without the central element are both analyzed by the Characteristic Mode Theory(CMT).The developed mutually orthogonal principal modes of the optimized periodic patch structure areexcited by a center-feed dipole.A differential feeding network is employed to realize impedance matching.Prototype with profile height of 0.07λ_(0)(λ_(0)is the wavelength in free space at the lowest operatingfrequency)is fabricated and assembled to verify the simulation results.The measured results show that thereflectance coefficient of proposed matesurface antenna is less than-10 dB in the whole operating bandrange from 4.2 GHz to 5.5 GHz,a relative bandwidth of 26.8%is achieved,and the maximummeasured realized gain is more than 9 dBi with a maximum radiation efficiency of 90%.The designprovides a guideline on the application of characteristic modes(CMs)to radiation problems.
基金the National Natural Science Foundation of China(No.12072309)the Youth Fund Foundation of Education Bureau of Hunan Province of China(No.19B546)the High-Level Talent Gathering Project in Hunan Province of China(No.2019RS1059)。
文摘The excessive deformation of deep-sea sediments caused by the vibration of the mining machine will adversely affect the efficiency and safety of mining.Combined with the deep-sea environment,the coupled thermo-hydro-mechanical problem for saturated porous deep-sea sediments subject to the vibration of the mining vehicle is investigated.Based on the Green-Lindsay(G-L)generalized thermoelastic theory and Darcy’s law,the model of thermo-hydro-mechanical dynamic responses for saturated porous deep-sea sediments under the vibration of the mining vehicle is established.We obtain the analytical solutions of non-dimensional vertical displacement,excess pore water pressure,vertical stress,temperature,and change in the volume fraction field with the normal mode analysis method,and depict them graphically.The normal mode analysis method uses the canonical coordinate transformation to solve the equation,which can quickly decouple the equation by ignoring the modal coupling effect on the basis of the canonical mode.The results indicate that the vibration frequency has obvious influence on the vertical displacement,excess pore water pressure,vertical stress,and change in volume fraction field.The loading amplitude has a great effect on the physical quantities in the foundation,and the changes of the physical quantities increase with the increase in loading amplitude.
文摘From the view of the physical model,structure and function characteristics,the material basis and clinical application of Yin-Yang theory,analysing and thinking combined with modern medical theory,this paper finds that as one of the most basic and important theory of traditional Chinese medicine(TCM),Yin-Yang theory reveals the understanding of human physiology in TCM,which has many consensuses with modern medicine,so it is worth studying further.
