The ligand ttd(ttd=1,4,8,9-Tetraaza-triphenylene-2,3-dicarbonitrile) and a novel spin crossover complex [Fe(ttd)2(NCS)2]·H2O were synthesized, and charac terized by elemental analysis, IR, MS, and UV-vis spectros...The ligand ttd(ttd=1,4,8,9-Tetraaza-triphenylene-2,3-dicarbonitrile) and a novel spin crossover complex [Fe(ttd)2(NCS)2]·H2O were synthesized, and charac terized by elemental analysis, IR, MS, and UV-vis spectroscopy. The temperature dependence of magnetic susceptibility shows that there are a little break betwe en 150～190K and an unusual step transition with a 50K width between 190～240K. Compared with the other complexes with the resemble structure, it can be found t hat the influence of ligand is very notable.展开更多
The true-time delay(TTD)units are critical for solving beam squint and frequency selective fading inWideband Large-Scale Antenna Systems(LSASs).In this work,we propose a TTD array architecture for wideband multi-beam ...The true-time delay(TTD)units are critical for solving beam squint and frequency selective fading inWideband Large-Scale Antenna Systems(LSASs).In this work,we propose a TTD array architecture for wideband multi-beam tracking that eliminates the beam squint phenomenon and filters out interference signals by applying a spatial filter and time delay estimations(TDEs).The paper presents a novel approach to spatial filter design by introducing a transformation matrix that can optimize the beam response in a specific direction and at a specific frequency.Using the variable fractional delay(VFD)filters,we propose a TDE algorithm with a Newton-Raphson iteration update process that corrects the arrival time delay difference between sensors.Simulations and examples have demonstrated that the proposed architecture can achieve beam tracking within 10 ms at the low signalto-noise ratio(SNR)and demodulation loss is less than 0.5 dB in wideband multi-beam scenarios.展开更多
文摘The ligand ttd(ttd=1,4,8,9-Tetraaza-triphenylene-2,3-dicarbonitrile) and a novel spin crossover complex [Fe(ttd)2(NCS)2]·H2O were synthesized, and charac terized by elemental analysis, IR, MS, and UV-vis spectroscopy. The temperature dependence of magnetic susceptibility shows that there are a little break betwe en 150～190K and an unusual step transition with a 50K width between 190～240K. Compared with the other complexes with the resemble structure, it can be found t hat the influence of ligand is very notable.
基金supported by the foundation of National Key Laboratory of Electromagnetic Environment(Grant No.202103012).
文摘The true-time delay(TTD)units are critical for solving beam squint and frequency selective fading inWideband Large-Scale Antenna Systems(LSASs).In this work,we propose a TTD array architecture for wideband multi-beam tracking that eliminates the beam squint phenomenon and filters out interference signals by applying a spatial filter and time delay estimations(TDEs).The paper presents a novel approach to spatial filter design by introducing a transformation matrix that can optimize the beam response in a specific direction and at a specific frequency.Using the variable fractional delay(VFD)filters,we propose a TDE algorithm with a Newton-Raphson iteration update process that corrects the arrival time delay difference between sensors.Simulations and examples have demonstrated that the proposed architecture can achieve beam tracking within 10 ms at the low signalto-noise ratio(SNR)and demodulation loss is less than 0.5 dB in wideband multi-beam scenarios.
