Time-modulated array(TMA)antennas,introduce the dimension of time into antenna design to control the radiation patterns and frequency spectral characteristics,thus improve the reconfigurability of array antennas and p...Time-modulated array(TMA)antennas,introduce the dimension of time into antenna design to control the radiation patterns and frequency spectral characteristics,thus improve the reconfigurability of array antennas and provide multiple functional-ities.They have great application potential in military and civilian fields,such as precision guidance and mobile communication,and are currently a hot spot of academic research.This article provides a review on the fundamentals and applications of TMAs.First,the basic theory and mathematical formulations of TMAs are introduced.Second,the most important applications of TMAs,namely time-modulated phased arrays(TMPA),are discussed from the perspectives of harmonic suppression and harmonic utiliza-tion,which are used for single-beam and multibeam radiation.Then,we survey the combination of TMA with various types of novel antenna arrays,such as single-channel digital beamforming(DBF)arrays,frequency diverse arrays(FDAs),and retrodirective arrays,to create new hardware implementation methods and enhance their performance.Next,recent advances in dedicated integrated chips for TMA,which have played a significant role in driving the progress of TMAs from academic research to practical applications,are presented.Finally,the challenges and prospects for TMAs are discussed,including new research directions and emerging applica-tion scenarios.展开更多
Summary of main observation and conclusion A vible light driven Cu()-catalyzed intermolecular oxyamination of electron-deficient olefins has been achieved by using O-benzoylhydroxylamines as donors both for amine and ...Summary of main observation and conclusion A vible light driven Cu()-catalyzed intermolecular oxyamination of electron-deficient olefins has been achieved by using O-benzoylhydroxylamines as donors both for amine and oxygen.The transformation properties afford mild conditions and a wide substrate scope,providing access to ester derivatives of 6-amino alcohols with good yields and high regioselectivity.展开更多
A series of novel P-stereogenic monophosphorus ligands (Xie-phos) were synthesized via the hydrophosphinylation of alkynes with secondary phosphine oxides by palladium catalysis and the following basemediated cyclizat...A series of novel P-stereogenic monophosphorus ligands (Xie-phos) were synthesized via the hydrophosphinylation of alkynes with secondary phosphine oxides by palladium catalysis and the following basemediated cyclization. They are easily synthesized and modified. Their utility was demonstrated in catalyticasymmetric reactions, including α-arylation of amides and the domino Heck/Suzuki reaction with moderate enantioselectivity.展开更多
The authors discuss the normality concerning holomorphic functions and get the following result. Let F be a family of functions holomorphic on a domain D C, all of whose zeros have multiplicity at least k, where k ≥...The authors discuss the normality concerning holomorphic functions and get the following result. Let F be a family of functions holomorphic on a domain D C, all of whose zeros have multiplicity at least k, where k ≥ 2 is an integer. Let h（z） ≠ 0 and oo be a meromorphic function on D. Assume that the following two conditions hold for every f C Dr ： （a） f（z） = 0 =→ ｜f（k）（z）｜ 〈｜h（z）｜. （b） f（k）（z） ≠ h（z）. Then F is normal on D.展开更多
We take up a new method to prove a Picard type theorem. Let f be a meromorphic function in the complex plane, whose zeros are multiple, and let R be a MSbius transformation. If limr→∞T（r,f）/r^2= ∞, then f＇（z） ...We take up a new method to prove a Picard type theorem. Let f be a meromorphic function in the complex plane, whose zeros are multiple, and let R be a MSbius transformation. If limr→∞T（r,f）/r^2= ∞, then f＇（z） = R（ez） has infinitely many solutions in the complex plane.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.62101258,62071235 and 62271260)the Jiangsu Province Science&Technology Department(Grant No.BE2021017).
文摘Time-modulated array(TMA)antennas,introduce the dimension of time into antenna design to control the radiation patterns and frequency spectral characteristics,thus improve the reconfigurability of array antennas and provide multiple functional-ities.They have great application potential in military and civilian fields,such as precision guidance and mobile communication,and are currently a hot spot of academic research.This article provides a review on the fundamentals and applications of TMAs.First,the basic theory and mathematical formulations of TMAs are introduced.Second,the most important applications of TMAs,namely time-modulated phased arrays(TMPA),are discussed from the perspectives of harmonic suppression and harmonic utiliza-tion,which are used for single-beam and multibeam radiation.Then,we survey the combination of TMA with various types of novel antenna arrays,such as single-channel digital beamforming(DBF)arrays,frequency diverse arrays(FDAs),and retrodirective arrays,to create new hardware implementation methods and enhance their performance.Next,recent advances in dedicated integrated chips for TMA,which have played a significant role in driving the progress of TMAs from academic research to practical applications,are presented.Finally,the challenges and prospects for TMAs are discussed,including new research directions and emerging applica-tion scenarios.
基金We are grateful to the Shanghai Sailing Program(No.16YF1402800)the 973 programs(No.2015CB856600)the National Natural Science Foundation of China(No.21425205)。
文摘Summary of main observation and conclusion A vible light driven Cu()-catalyzed intermolecular oxyamination of electron-deficient olefins has been achieved by using O-benzoylhydroxylamines as donors both for amine and oxygen.The transformation properties afford mild conditions and a wide substrate scope,providing access to ester derivatives of 6-amino alcohols with good yields and high regioselectivity.
基金funding support of the NSFC(22031004,21921003,and 21901043),STCSM(21ZR1445900)Shanghai Municipal Education Commission(20212308).
文摘A series of novel P-stereogenic monophosphorus ligands (Xie-phos) were synthesized via the hydrophosphinylation of alkynes with secondary phosphine oxides by palladium catalysis and the following basemediated cyclization. They are easily synthesized and modified. Their utility was demonstrated in catalyticasymmetric reactions, including α-arylation of amides and the domino Heck/Suzuki reaction with moderate enantioselectivity.
基金Project supported by the National Natural Science Foundation of China(No.11071074)the Outstanding Youth Foundation of Shanghai(No.slg10015)
文摘The authors discuss the normality concerning holomorphic functions and get the following result. Let F be a family of functions holomorphic on a domain D C, all of whose zeros have multiplicity at least k, where k ≥ 2 is an integer. Let h（z） ≠ 0 and oo be a meromorphic function on D. Assume that the following two conditions hold for every f C Dr ： （a） f（z） = 0 =→ ｜f（k）（z）｜ 〈｜h（z）｜. （b） f（k）（z） ≠ h（z）. Then F is normal on D.
基金This work was supported by the National Natural Science Foundation of China （Grant Nos. 11501367, 11671191）
文摘We take up a new method to prove a Picard type theorem. Let f be a meromorphic function in the complex plane, whose zeros are multiple, and let R be a MSbius transformation. If limr→∞T（r,f）/r^2= ∞, then f＇（z） = R（ez） has infinitely many solutions in the complex plane.
