A scanning and uniform array architecture with large spacing,low complexity and high scalability is presented for high integration massive array applications.It is constructed by offset phase center elements arranged ...A scanning and uniform array architecture with large spacing,low complexity and high scalability is presented for high integration massive array applications.It is constructed by offset phase center elements arranged in a uniform and regular way,but its spacing can be larger than that of traditional arrays.An ideal model of the offset phase center element is established and its far-field distribution is derived.To suppress grating lobes,the phase center of any element is designed to be movable without changing its physical position.Using genetic algorithm(GA),a new constraint condition limiting the number of phase center changes is proposed to solve the objective function of the minimum values of grating lobes(GLs)and side lobes(SLs).It is shown that the optimal results can be achieved by two changes of phase centers.A multimode circular patch is developed and designed,and characteristics of the offset phase center are analyzed and verified.A prototype array of 12×12 offset phase center elements is implemented based on multi-mode circular patches.Full wave simulation results of radiation patterns show that the level of grating lobes is suppressed at least 7dB with 1.12λ spacing,while the scanning angle is 20°.展开更多
In the present work,cyclic voltammetry(CV),square wave voltammetry(SWV)and chronopotentiometry(CP)were used to investigate the electrochemical coreduction behaviors of La(Ⅲ)and Mg(Ⅱ)as well as La(Ⅲ),Mg(Ⅱ)and Mn(Ⅱ...In the present work,cyclic voltammetry(CV),square wave voltammetry(SWV)and chronopotentiometry(CP)were used to investigate the electrochemical coreduction behaviors of La(Ⅲ)and Mg(Ⅱ)as well as La(Ⅲ),Mg(Ⅱ)and Mn(Ⅱ)on Mo electrode in LiCl+KCl molten salts.CV and SWV results exhibit that the coreduction mechanism of La(Ⅲ)and Mg(Ⅱ)on Mo electrode is that La(Ⅲ)is reduced and Mg-La intermetallic compound is formed,leading to the deposition potential of La(Ⅲ)shifting to more positive one.The electrochemical signals pertaining to the formation of metallic La,Mg and Mn as well as Mg-La intermetallic compound are also observed by coreduction of La(Ⅲ),Mg(Ⅱ),and Mn(Ⅱ)in LiCl+KCl molten salt on the inert Mo electrode.However,the electrochemical signals associated with the formation of La-Mn and Mg-Mn alloys are not observed,which means that the depolarization effect of La(Ⅲ)and Mg(Ⅱ)does not occur on pre-deposited Mn electrode.The Mg-La-Mn alloys were formed by co-deposition of La(Ⅲ),Mg(Ⅱ),and Mn(Ⅱ)on Mo electrode at various concentration ratios of La(Ⅲ)and Mg(Ⅱ).The results of scanning electron microscopy equipped with energy dispersive spectroscopy and X-ray diffraction displays that the Mg-La-Mn alloys are comprised of La-Mg compound Mg_(17)La_(2),Mg and Mn phases.The concentration ratio of La(Ⅲ)and Mn(Ⅱ)has few effects on the alloy composition.展开更多
基金This work was supported by National Natural Science Foundation of China(No.U19B2028).
文摘A scanning and uniform array architecture with large spacing,low complexity and high scalability is presented for high integration massive array applications.It is constructed by offset phase center elements arranged in a uniform and regular way,but its spacing can be larger than that of traditional arrays.An ideal model of the offset phase center element is established and its far-field distribution is derived.To suppress grating lobes,the phase center of any element is designed to be movable without changing its physical position.Using genetic algorithm(GA),a new constraint condition limiting the number of phase center changes is proposed to solve the objective function of the minimum values of grating lobes(GLs)and side lobes(SLs).It is shown that the optimal results can be achieved by two changes of phase centers.A multimode circular patch is developed and designed,and characteristics of the offset phase center are analyzed and verified.A prototype array of 12×12 offset phase center elements is implemented based on multi-mode circular patches.Full wave simulation results of radiation patterns show that the level of grating lobes is suppressed at least 7dB with 1.12λ spacing,while the scanning angle is 20°.
基金Project supported by the National Natural Science Foundation of China(21790373,21876034,11875116,11675044,11575047)。
文摘In the present work,cyclic voltammetry(CV),square wave voltammetry(SWV)and chronopotentiometry(CP)were used to investigate the electrochemical coreduction behaviors of La(Ⅲ)and Mg(Ⅱ)as well as La(Ⅲ),Mg(Ⅱ)and Mn(Ⅱ)on Mo electrode in LiCl+KCl molten salts.CV and SWV results exhibit that the coreduction mechanism of La(Ⅲ)and Mg(Ⅱ)on Mo electrode is that La(Ⅲ)is reduced and Mg-La intermetallic compound is formed,leading to the deposition potential of La(Ⅲ)shifting to more positive one.The electrochemical signals pertaining to the formation of metallic La,Mg and Mn as well as Mg-La intermetallic compound are also observed by coreduction of La(Ⅲ),Mg(Ⅱ),and Mn(Ⅱ)in LiCl+KCl molten salt on the inert Mo electrode.However,the electrochemical signals associated with the formation of La-Mn and Mg-Mn alloys are not observed,which means that the depolarization effect of La(Ⅲ)and Mg(Ⅱ)does not occur on pre-deposited Mn electrode.The Mg-La-Mn alloys were formed by co-deposition of La(Ⅲ),Mg(Ⅱ),and Mn(Ⅱ)on Mo electrode at various concentration ratios of La(Ⅲ)and Mg(Ⅱ).The results of scanning electron microscopy equipped with energy dispersive spectroscopy and X-ray diffraction displays that the Mg-La-Mn alloys are comprised of La-Mg compound Mg_(17)La_(2),Mg and Mn phases.The concentration ratio of La(Ⅲ)and Mn(Ⅱ)has few effects on the alloy composition.
