With the rapid advancement of technology,not only do we need to acquire a clear in-verse synthetic aperture radar(ISAR)image,but also the real size of the target on the imaging plane,so it’s particularly important fo...With the rapid advancement of technology,not only do we need to acquire a clear in-verse synthetic aperture radar(ISAR)image,but also the real size of the target on the imaging plane,so it’s particularly important for the ISAR to rescale the images.That is,the ISAR image which is in the range-Doppler domain is converted into the range-azimuth domain.Actually,the key point to solving the problem is to estimate the rotation parameters.In this paper,a new scheme to rescale the images is proposed.For the sake of solving the problem of two-dimensional image blur and target high-speed,the instantaneous range instantaneous Doppler(IRID)method is used to obtain ISAR images,and the rotation parameters are estimated by comparing the rotation correlation of the two images.Using this method,the error of the estimated rotation parameters is greatly reduced,so that the target can be rescaled accurately.The simulation results verify the ef-fectiveness of the proposed algorithm.展开更多
Metal oxide semiconductor heterojunctions(MOSHs)can enhance the performance of ethanol gas sen-sors substantially.Ethanol gas sensors based on MOSHs are cost-effective and have excellent sensing response,good selectiv...Metal oxide semiconductor heterojunctions(MOSHs)can enhance the performance of ethanol gas sen-sors substantially.Ethanol gas sensors based on MOSHs are cost-effective and have excellent sensing response,good selectivity,fast response and recovery,long-term stability or repeatability,a low operating temperature,a facile fabrica-tion process,and versatile applications.This paper reviews the recent advances in gas sensors that are based on MOSHs and the advantages of using them to detect ethanol gas.According to the literature,compared with ethanol gas sen-sors that use single-component sensing materials,the MOSHs exhibit superior performance due to the synergy between the different components,which can amplify the reception and transduction components of the sensor signals.To the best of our knowledge,heterojunctions can be grouped into four main categories as metal oxide/metal oxide,metal oxide/metal sulfide,metal oxide/noble metal,and metal oxide/other materials,including rare-earth metals,g-C_(3)N_(4),and graphene,heterojunctions.The future trends and challenges that would be faced in the development of ethanol gas sensors based on MOSHs are discussed in detail.Finally,critical ideas and thinking regarding the future progress of MOSH-based gas sensors are presented.展开更多
We obtain the enhanced stimulated Brillouin scattering(SBS)by adding the optimized Bragg grating to an As_(2)S_(3) chalcogenide half suspended-core rectangle waveguide.The half suspended-core waveguide grating is char...We obtain the enhanced stimulated Brillouin scattering(SBS)by adding the optimized Bragg grating to an As_(2)S_(3) chalcogenide half suspended-core rectangle waveguide.The half suspended-core waveguide grating is characterized by the period of 344.67 nm and the refractive index modulation depth of 0.0001.Through simulation experiments,the obtained Brillouin gain is 58.5 dB and the 3 dB bandwidth can reduce to 7.8 MHz.The half suspended-core waveguide structure can decrease the size of the chip while the periodic structure can enhance the slow light effect,so we have improved the integration of the waveguide and enhanced SBS by combining these two advantages.展开更多
基金supported in part by the National Natural Sci-ence Foundation of China(No.61875070)in part by the Science and Technology Development Plan of Jilin Province(No.20180201032GX)+1 种基金in part by the Science and Techno-logy Project of Education Department of Jilin Province(No.JJKH20190110KJ)in part by the Graduate In-novation Fund of Jilin University(No.101832020CX171).
文摘With the rapid advancement of technology,not only do we need to acquire a clear in-verse synthetic aperture radar(ISAR)image,but also the real size of the target on the imaging plane,so it’s particularly important for the ISAR to rescale the images.That is,the ISAR image which is in the range-Doppler domain is converted into the range-azimuth domain.Actually,the key point to solving the problem is to estimate the rotation parameters.In this paper,a new scheme to rescale the images is proposed.For the sake of solving the problem of two-dimensional image blur and target high-speed,the instantaneous range instantaneous Doppler(IRID)method is used to obtain ISAR images,and the rotation parameters are estimated by comparing the rotation correlation of the two images.Using this method,the error of the estimated rotation parameters is greatly reduced,so that the target can be rescaled accurately.The simulation results verify the ef-fectiveness of the proposed algorithm.
基金financially supported by Brain Pool program funded by the Ministry of Science and ICT through the National Research Foundation of Korea (No.2021H1D3A2A01100019)the National Natural Science Foundation of China (No.62074057)+2 种基金Projects of Science and Technology Commission of Shanghai Municipality (Nos.19ZR1473800 and 18DZ2270800)the Open Research Projects of Zhejiang Lab (No.2021MCOAB06)the Postdoctoral Scientific Research Foundation of Qingdao
文摘Metal oxide semiconductor heterojunctions(MOSHs)can enhance the performance of ethanol gas sen-sors substantially.Ethanol gas sensors based on MOSHs are cost-effective and have excellent sensing response,good selectivity,fast response and recovery,long-term stability or repeatability,a low operating temperature,a facile fabrica-tion process,and versatile applications.This paper reviews the recent advances in gas sensors that are based on MOSHs and the advantages of using them to detect ethanol gas.According to the literature,compared with ethanol gas sen-sors that use single-component sensing materials,the MOSHs exhibit superior performance due to the synergy between the different components,which can amplify the reception and transduction components of the sensor signals.To the best of our knowledge,heterojunctions can be grouped into four main categories as metal oxide/metal oxide,metal oxide/metal sulfide,metal oxide/noble metal,and metal oxide/other materials,including rare-earth metals,g-C_(3)N_(4),and graphene,heterojunctions.The future trends and challenges that would be faced in the development of ethanol gas sensors based on MOSHs are discussed in detail.Finally,critical ideas and thinking regarding the future progress of MOSH-based gas sensors are presented.
基金supported by the National Natural Science Foundation of China(No.61875070)the Science and Technology Development Plan of Jilin Province(No.20180201032GX)the Science and Technology Project of Education Department of Jilin Province(No.JJKH20190110KJ)。
文摘We obtain the enhanced stimulated Brillouin scattering(SBS)by adding the optimized Bragg grating to an As_(2)S_(3) chalcogenide half suspended-core rectangle waveguide.The half suspended-core waveguide grating is characterized by the period of 344.67 nm and the refractive index modulation depth of 0.0001.Through simulation experiments,the obtained Brillouin gain is 58.5 dB and the 3 dB bandwidth can reduce to 7.8 MHz.The half suspended-core waveguide structure can decrease the size of the chip while the periodic structure can enhance the slow light effect,so we have improved the integration of the waveguide and enhanced SBS by combining these two advantages.
