Pulse-Width Pulse-Frequency Based Optimal Controller Design for Kinetic Kill Vehicle Attitude Tracking Control

The attitude control problem of the kinetic kill vehicle is studied in this work. A new mathematical model of the kinetic kill vehicle is proposed, the linear quadratic regulator technique is used to design the optimal attitude controller, and the pulse-width pulse-frequency modulator is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the reaction thrusters. The methods to select the appropriate parameters of pulse-width pulse-frequency are presented in detail. Numerical simulations show that the performance of the LQR/PWPF approach can achieve good control performance such as pseudo-linear operation, high accuracy, and fast enough tracking speed.

Simulations of NBI fast ion loss in the presence of toroidal field ripple on EAST

NBI fast ion losses in the presence of the toroidal field ripple on EAST have been investigated by using the orbit code GYCAVA and the NBI code TGCO.The ripple effect was included in the upgraded version of the GYCAVA code.It is found that loss regions of NBI fast ions are mainly on the low field side near the edge in the presence of ripple.For co-current NBIs,the synergy effect of ripple and Coulomb collision on fast ion losses is dominant,and fast trapped ions located on the low field side are easily lost.The ripple well loss and the ripple stochastic loss of fast ions have been identified from the heat loads of co-current NBI fast ions.The ripple stochastic loss and the collisioninduced loss are much larger than the ripple well loss.Heat loads of lost fast ions are mainly localized on the right side of the radio frequency wave antennas from the inside view toward the first wall.For counter-current NBIs,the first orbit loss due to the magnetic drift is the dominant loss channel.In addition,fast ion loss fraction with ripple and collision for each NBI linearly increases with the effective charge number,which is related to the pitch angle scattering effect.

Orthogonally polarized RF optical single sideband generation with integrated ring resonators

We review recent work on narrowband orthogonally polarized optical RF single sideband generators as well as dualchannel equalization,both based on high-Q integrated ring resonators.The devices operate in the optical telecommunications C-band and enable RF operation over a range of either fixed or thermally tuneable frequencies.They operate via TE/TM mode birefringence in the resonator.We achieve a very large dynamic tuning range of over 55 dB for both the optical carrier-to-sideband ratio and the dual-channel RF equalization for both the fixed and tunable devices.

Simulations of first-orbit losses of neutral beam injection(NBI)fast ions on EAST

Simulations of first-orbit losses of neutral beam injection(NBI)fast ions in the EAST tokamak have been studied in detail by using the orbit-following code GYCAVA and the NBI code TGCO.Beam ion losses with the wall boundary are smaller than those with the last closed flux surface boundary.In contrast to heat loads on the wall without radio frequency wave(RFW)antennas,heat loads on the wall with RFW antennas are distributed more locally near the RFW antennas.The direction of the toroidal magnetic field dramatically affects the final positions of lost fast ions,which is related to the magnetic drift.The numerical results on heat loads of beam ions corresponding to different toroidal magnetic fields are qualitatively consistent with the experimental results.Beam ion losses increase with the beam energy for the co-current NBIs and the counter-perpendicular NBI.We have studied the behavior of fast ions produced by a small section neutral beam(beamlet)by using the numerical tool NBIT.The distributions of the loss fraction of beamlet fast ions peaked near the edge of the beam section for the counter-current NBIs,and they are related to the injection angle.This indicates that the first-orbit losses can be reduced by changing the shape of beam cross section.

Photonic radio frequency channelizers based on Kerr optical micro-combs

We review recent work on broadband RF channelizers based on integrated optical frequency Kerr micro-combs combined with passive micro-ring resonator filters,with microcombs having channel spacings of 200 and 49 GHz.This approach to realizing RF channelizers offers reduced complexity,size,and potential cost for a wide range of applications to microwave signal detection.

Photonic microwave true time delays for phased array antennas using a 49 GHz FSR integrated optical micro-comb source[Invited]

We demonstrate significantly improved performance of a microwave true time delay line based on an integrated optical frequency comb source. The broadband micro-comb(over 100 nm wide) features a record low free spectral range(FSR) of 49 GHz, resulting in an unprecedented record high channel number(81 over the C band)—the highest number of channels for an integrated comb source used for microwave signal processing. We theoretically analyze the performance of a phased array antenna and show that this large channel count results in a high angular resolution and wide beam-steering tunable range. This demonstrates the feasibility of our approach as a competitive solution toward implementing integrated photonic true time delays in radar and communications systems.

The AKT-independent MET–V-ATPase–MTOR axis suppresses liver cancer vaccination

Despite recent progress in hepatitis treatment,there have been no significant advances in the development of liver cancer vaccines in recent years.In this study,we investigated the regulatory effect and potential mechanism of hepatocyte growth factor receptor(MET,also known as HGFR)on tumor vaccinations for liver cancer in mice.Herein,we demonstrate that MET expression is significantly associated with the immunogenicity of liver cancer in mice and humans,and that MET depletion dramatically enhances the protective efficacy of chemotherapy-based anti-liver cancer vaccination.Mechanistically,MET repressed liver cancer immunogenicity independent of the traditional PI3K–AKT cascade,and MET interacted with vacuolar ATP synthase(V-ATPase)and mediated the activation of mammalian target of rapamycin(MTOR),thus suppressing liver cancer immunogenicity.The efficacy of chemotherapy-based liver cancer vaccination was markedly enhanced by targeting the MET–V-ATPase–MTOR axis,highlighting a translational strategy for identifying MET-associated drug candidates for cancer prevention.