The scattering centers(SCs)of low-detectable targets(LDTs)have a low scattering intensity.It is difficult to build the SC model of an LDT using the existing methods because these methods mainly concern dominant SCs wi...The scattering centers(SCs)of low-detectable targets(LDTs)have a low scattering intensity.It is difficult to build the SC model of an LDT using the existing methods because these methods mainly concern dominant SCs with strong scattering contributions.This paper presents an SC modeling approach to acquire the weak SCs of LDTs.We employ the induced currents at the LDT to search SCs,and the joint time-frequency transform together with the Hough transform to separate the scattering contributions of different SCs.Particle swarm optimization(PSO)is applied to improve the estimation results of SCs.The accuracy of the SC model built by this approach is verified by a full-wave numerical method.The validation results show that the SC model of the LDT can precisely simulate the signatures of high-resolution images,such as high-resolution range profile and inverse synthetic aperture radar(ISAR)images.展开更多
To realize highly selective relay recognition of Fe3＋ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor （L） was designed and synthesized. Sensor L displays rapid, highly selective, and sensitiv...To realize highly selective relay recognition of Fe3＋ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor （L） was designed and synthesized. Sensor L displays rapid, highly selective, and sensitive recognition to Fe^3＋ in H2O/DMSO （1：1, v/v） solutions. The in stitu-generated L-Fe^3＋ complex solution exhibits a fast response and high selectivity toward dihydrogen phosphate anion via the Fe^3＋ displacement approach. The detection limits of sensor L to Fe^3＋ and L-Fe^3＋complex to H2PO4 anion were estimated to be 1.0 × 10^-9 mol/L. Notably, the sensor was retrievable to indicate dihydrogen phosphate an- ions with Fe^3＋, and HePO4 , in turn, increased. This successive recognition feature of sensor L makes it a potential utility for Fe^3＋ and H2PO4 anion detection in aqueous media.展开更多
基金This work was supported by the National Key R&D Program of China(2017YFB0202500)the National Natural Science Foundation of China(61771052).
文摘The scattering centers(SCs)of low-detectable targets(LDTs)have a low scattering intensity.It is difficult to build the SC model of an LDT using the existing methods because these methods mainly concern dominant SCs with strong scattering contributions.This paper presents an SC modeling approach to acquire the weak SCs of LDTs.We employ the induced currents at the LDT to search SCs,and the joint time-frequency transform together with the Hough transform to separate the scattering contributions of different SCs.Particle swarm optimization(PSO)is applied to improve the estimation results of SCs.The accuracy of the SC model built by this approach is verified by a full-wave numerical method.The validation results show that the SC model of the LDT can precisely simulate the signatures of high-resolution images,such as high-resolution range profile and inverse synthetic aperture radar(ISAR)images.
基金supported by the National Natural Science Foundation of China(21064006,21161018,21262032)the Natural Science Foundation of Gansu Province(1010RJZA018)+1 种基金the Program for Changjiang ScholarsInnovative Research Teams in Universities of the Ministry of Education of China(IRT1177)
文摘To realize highly selective relay recognition of Fe3＋ and H2PO4^- ions, a simple benzimidazole-based fluorescent chemosensor （L） was designed and synthesized. Sensor L displays rapid, highly selective, and sensitive recognition to Fe^3＋ in H2O/DMSO （1：1, v/v） solutions. The in stitu-generated L-Fe^3＋ complex solution exhibits a fast response and high selectivity toward dihydrogen phosphate anion via the Fe^3＋ displacement approach. The detection limits of sensor L to Fe^3＋ and L-Fe^3＋complex to H2PO4 anion were estimated to be 1.0 × 10^-9 mol/L. Notably, the sensor was retrievable to indicate dihydrogen phosphate an- ions with Fe^3＋, and HePO4 , in turn, increased. This successive recognition feature of sensor L makes it a potential utility for Fe^3＋ and H2PO4 anion detection in aqueous media.
