Anti-Jamming Null Space Projection Beamforming Based on Symbiotic Radio

With the development of information technology,more and more devices are connected to the Internet through wireless communication to complete data interconnection.Due to the broadcast characteristics ofwireless channels,wireless networks have suffered more and more malicious attacks.Physical layer security has received extensive attention from industry and academia.MIMO is considered to be one of the most important technologies related to physical layer security.Through beamforming technology,messages can be transmitted to legitimate users in an offset direction that is as orthogonal as possible to the interference channel to ensure the reception SINR by legitimate users.Combining the symbiotic radio(SR)technology,this paper considers a symbiotic radio antijamming MIMO system equipped with a multi-antenna system at the main base station.In order to avoid the interference signal and improve the SINR of the signal received by the user.The base station is equipped with a uniform rectangular antenna array,and using Null Space Projection(NSP)Beamforming,Intelligent Reflecting Surface(IRS)can assist in changing the beam’s angle.The simulation results show that NSP Beamforming could make a better use of the null space of interference,which can effectively improve the received SINR of users under directional interference,and improve the utilization efficiency of signal energy.

Castleman病的临床病理特征及可能的发病机制

Castleman病(Castleman disease,CD)是一类高度临床异质性和特征病理反应性淋巴结增生性疾病,较为少见,目前病因及发病机制尚未明确。单中心型(unicentric CD,UCD)的致病机制很可能是由肿瘤间质细胞克隆性增殖及获得性突变引起的。特发性多中心型(idiopathic multicentric CD,iMCD)在临床表现和病理特征上与多种疾病相交叉,已发现的较常见的致病因素有自身免疫性因素、副肿瘤综合征、病毒感染性因素以及炎症因子的失调。iMCD的致病机制很可能由多种病因综合作用引起免疫调节失调和细胞因子增加的共同途径产生。本文总结近年来CD最新病因及发病机制,旨在加深对该疾病的认识。

On-chip terahertz orbital angular momentum demultiplexer

The terahertz regime is widely recognized as a fundamental domain with significant potential to address the demands of next-generation wireless communications.In parallel,mode division multiplexing based on orbital angular momentum(OAM)shows promise in enhancing bandwidth utilization,thereby expanding the overall communication channel capacity.In this study,we present both theoretical and experimental demonstrations of an on-chip terahertz OAM demultiplexer.This device effectively couples and steers seven incident terahertz vortex beams into distinct high-quality focusing surface plasmonic beams,and the focusing directions can be arbitrarily designated.The proposed design strategy integrates space-to-chip mode conversion,OAM recognition,and on-chip routing in a compact space with subwavelength thickness,exhibiting versatility and superior performance.

Generating superposed terahertz perfect vortices via a spin-multiplexed all-dielectric metasurface

Perfect optical vortices(POVs),characterized as a ring radius independent of topological charge(TC),possess extensive application in particle manipulation and optical communication.At present,the complex and bulky optical device for generating POVs has been miniaturized by leveraging the metasurface,and either spindependent or spin-independent POV conversions have been further accomplished.Nevertheless,it is still challenging to generate superposed POVs for incidences with orthogonal circular polarization.Here,a spinmultiplexed all-dielectric metasurface method for generating superposed POVs in the terahertz frequency range is proposed and demonstrated.By using the multiple meta-atom comprised structure as the basic unit,the complex amplitude of two superposed POVs is modulated,decoupled,and subsequently encoded to left-and righthanded circular polarization incidences.Furthermore,two kinds of metasurfaces are fabricated and characterized to validate this controlling method.It is demonstrated that the measured intensity and phase distributions match well with the calculation of the Rayleigh–Sommerfeld diffraction integral,and the radius of superposed POVs is independent of TCs.This work provides promising opportunities for developing ultracompact terahertz functional devices applied to complex structured light generation and terahertz communication,and exploring sophisticated spin angular momentum and orbital angular momentum interactions like the photonic spin-Hall effect.

Combined insertion of basic and non-basic amino acids at hemagglutinin cleavage site of highly pathogenic H7N9 virus promotes replication and pathogenicity in chickens and mice

Since mid-2016,the low pathogenic H7N9 influenza virus has evolved into a highly pathogenic(HP)phenotype in China,raising many concerns about public health and poultry industry.The insertion of a“KRTA”motif at hemagglutinin cleavage site(HACS)occurred in the early stage of HP H7N9 variants.During the co-circulation,the HACS of HP-H7N9 variants were more polymorphic in birds and humans.Although HP-H7N9 variants,unlike the H5 subtype virus,exhibited the insertions of basic and non-basic amino acids,the underlying function of those insertions and substitutions remains unclear.The results of bioinformatics analysis indicated that the PEVPKRKRTAR/G motif of HACS had become the dominant motif in China.Then,we generated six H7N9 viruses bearing the PEIPKGR/G,PEVPKGR/G,PEVPKRKRTAR/G,PEVPKGKRTAR/G,PEVPKGKRIAR/G,and PEVPKRKRR/G motifs.Interestingly,after the deletion of threonine and alanine(TA)at HACS,the H7N9 viruses manifested decreased thermostability and virulence in mice,and the PEVPKRKRTAR/G-motif virus is prevalent in birds and humans probably due to its increased transmissibility and moderate virulence.By contrast,the insertion of non-basic amino acid isoleucine and alanine(IA)decreased the transmissibility in chickens and virulence in mice.Remarkably,the I335V substitution of H7N9 virus enhanced infectivity and transmission in chickens,suggesting that the combination of mutations and insertions of amino acids at the HACS promoted replication and pathogenicity in chickens and mice.The ongoing evolution of H7N9 increasingly threatens public health and poultry industry,so,its comprehensive surveillance and prevention of H7N9 viruses should be pursued.