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Joint Active and Passive Beamforming Design in Intelligent Reflecting Surface(IRS)-Assisted Covert Communications:A Multi-Agent DRL Approach

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China Communications 2024年第9期21卷 11-26页

作者： Gao ang Ren xiaoyu Deng Bin Sun Xinshun z.ang Jiankang School of Electronic Information Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Near Ground Detection and Perception Technology Wuxi 214035China Department of Computing and Informatics Bournemouth UniversityUK

Intelligent Reflecting Surface(IRS),with the potential capability to reconstruct the electromagnetic propagation environment,evolves a new IRSassisted covert communications paradigm to eliminate the negligible detection of malicious eavesdroppers by coherently beaming the scattered signals and suppressing the signals ***,when multiple IRSs are involved,accurate channel estimation is still a challenge due to the extra hardware complexity and communication *** the crossinterference caused by massive reflecting paths,it is hard to obtain the close-formed solution for the optimization of covert *** this basis,the paper improves a heterogeneous multi-agent deep deterministic policy gradient(MADDPG)approach for the joint active and passive beamforming(Joint A&P BF)optimization without the channel estimation,where the base station(BS)and multiple IRSs are taken as different types of agents and learn to enhance the covert spectrum efficiency(CSE)*** to the‘centralized training and distributed execution’feature of MADDPG,each agent can execute the active or passive beamforming independently based on its partial observation without referring to *** results demonstrate that the proposed deep reinforcement learning(DRL)approach could not only obtain a preferable CSE of legitimate users and a low detection of probability(LPD)of warden,but also alleviate the communication overhead and simplify the IRSs deployment.

关键词： covert communications deep reinforcement learning intelligent reflecting surface

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AWells-Riley/based COVID-19 infectiousrisk assessment model combining both short rangeandroom scale effects

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Building Simulation 2024年第1期17卷 93-111页

作者： Yinshuai Feng Yifan Fan xiaoyu Luo Jian Ge College of Civil Engineering and Architecture Zhejiang UniversityHangzhouChina Center for Balance Architecture Zhejiang UniversityHangzhouChina International Research Center for Green Building and Low-Carbon City International CampusZhejiang UniversityHainingChina

There is growing evidence of the high transmission potential of COVID-19 through virus-laden *** aerosols are inhaled in various concentrations,an overall assessment of transmission risks at different indoor scales is ***,a comprehensive risk assessment method that evaluates the direct link between short-range and room-scale zones is stl *** this paper,a risk assessment model combining both short-range and room-scale effects is developed to obtain effective reproduction number in confined indoor environments,called Turbulent Jet Wells Riley(TJWR)*** with the viral load data and aerosol generation data of different human respiratory activities,the Monte Carlo simulation method is applied to calculate the quanta emission rate,which further provides the input parameters of the TJWR *** known outbreaks(Hangzhou banquet hall X,Guangzhou restaurant Y,and Hong Kong restaurant z,China)are chosen to validate the TJWR *** show that the TJWR model is more efficient than the original Wells-Riley *** average relative error of the TJWR model ranges between 9%and 44%,while for the Wells-Riley model,it ranges between 57%and 78%.The TJWR model also proves that infection risk assessments using the well-mixed assumption can systematically underestimate the transmission risk for those close to the ***,there is a significant positive linear correlation between the total number of exposed individuals at the short-range and the effective reproduction *** newly developed TJWR model has great potential for rapid and real-time overall airborne transmission risk assessment in buildings and cities.

关键词： COVID-19 airborne transmission infection risk Wells-Riley model Monte Carlo simulation

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Characteristics and close-range exploration methods of near- Earth asteroid 2016HO_(3)

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Astronomical Techniques and Instruments 2024年第1期1卷 42-51页

作者： He z.ang Fei Li Linzhi Meng Fuming zeng xiaoyu Jia Yu’ang Liu Beijing Institute of Spacecraft System Engineering Beijing 100094China

The characteristics of asteroids are vital parameters for planning asteroid exploration *** characteristics have been explored in close range for some typical asteroids,and are summarized in the *** allows estimates of the characteristics of asteroid 2016HO_(3),the target of the first Chinese asteroid exploration mission,Tianwen *** obtain 80 characteristic parameters in 9 categories and analyze their impacts on the *** comparing three close-range exploration modes,we provide advantages and disadvantages of each,and propose suitable methods for the exploration of 2016HO_(3).Owing to the weak gravity and small size of 2016HO_(3),a combination of multiple hovering positions and active orbiting is recommended for scientific exploration.

关键词： Near-Earth asteroid 2016HO_(3) Tianwen 2 Close-range exploration Characteristics

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Mechanism of high-preload support based on the NPR anchor cable in layered soft rock tunnels

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Journal of Mountain Science 2024年第4期21卷 1403-1418页

作者： SUI Qiru HE Manchao SHI Mengfan TAO zhigang zHAO Feifei z.ang xiaoyu State Key Laboratory for Tunnel Engineering China University of Mining and Technology(Beijing)Beijing 100083China School of Mechanics and Civil Engineering China University of Mining and Technology(Beijing)Beijing 100083China

The control of large deformation problems in layered soft rock tunnels needs to solve *** roof problem is particularly severe among the deformation issues in *** study first analyzes the asymmetric deformation modes in layered soft rock tunnels with large ***,we construct a mechanical model under ideal conditions for controlling the roof of layered soft rock tunnels through high preload with the support of NPR anchor *** prominent roles of long and short NPR anchor cables in the support system are also *** results indicate the significance of high preload in controlling the roof of layered soft rock *** short NPR anchor cables effectively improve the integrity of the stratified soft rock layers,while the long NPR anchor cables effectively mobilize the self-bearing capacity of deep-stable rock ***,the high-preload support method with NPR anchor cables is validated to have a good effect on controlling large deformations in layered soft rock tunnels through field monitoring data.

关键词： Tunnel engineering Soft rock High-preload support NPR anchor cables

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Uncertainty quantification of inverse analysis for geomaterials using probabilistic programming

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 895-908页

作者： Hongbo zhao Shaojun Li xiaoyu zang Xinyi Liu Lin z.ang Jiaolong Ren School of Civil Engineering and Geomatics Shandong University of TechnologyZibo255000China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China

Uncertainty is an essentially challenging for safe construction and long-term stability of geotechnical *** inverse analysis is commonly utilized to determine the physico-mechanical ***,conventional inverse analysis cannot deal with uncertainty in geotechnical and geological *** this study,a framework was developed to evaluate and quantify uncertainty in inverse analysis based on the reduced-order model(ROM)and probabilistic *** ROM was utilized to capture the mechanical and deformation properties of surrounding rock mass in geomechanical *** programming was employed to evaluate uncertainty during construction in geotechnical engineering.A circular tunnel was then used to illustrate the proposed framework using analytical and numerical *** results show that the geomechanical parameters and associated uncertainty can be properly obtained and the proposed framework can capture the mechanical behaviors under ***,a slope case was employed to demonstrate the performance of the developed *** results prove that the proposed framework provides a scientific,feasible,and effective tool to characterize the properties and physical mechanism of geomaterials under uncertainty in geotechnical engineering problems.

关键词： Geological engineering Geotechnical engineering Inverse analysis Uncertainty quantification Probabilistic programming

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Exploring the Mechanism,Advancements,and Application of Thermogalvanic Effect in Hydrogels

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Chinese Journal of Chemistry 2024年第5期42卷 543-556页

作者： xiaoyu Yang Peng Wang Xiaolong Wu Yongli Liao Senyun Liu Wei Duan Ying Yue School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBaodingHebei071000 China Hebei Key Laboratory of Electric Machinery Health Maintenance & Failure Prevention North China Electric Power UniversityBaodingHebei071003 China Electric Power Research Institute China South Power GridGuangzhouGuangdong510000 China Key Laboratory of Icing and Anti/De-icing China Aerodynamics Research and Development CenterMianyangSichuan621000 China

The issue of energy consumption has garnered significant interest due to its excessive ***,thermoelectric devices have been getting increased attention,as they can harness waste heat from various sources,such as solar radiation,human body,and industrial ***,the recovery of low-grade heat has been a challenge,resulting in unsustainable energy use and significant *** considerable advances have been made in thermoelectric materials in recent decades,the majority of these devices still primarily employ ***,the emergence of quasi-solid-state thermoelectric materials represents a novel development with profound promise for the environment and *** materials offer several advantages,such as improved energy conversion capacities,cost-effectiveness,versatility,and scalability,to support increased ***,this review explores the application of thermoelectric materials in self-powered sensors,integrated modules,and heat harvesting ***,the potential of high-performance thermocouples based on thermogalvanic effects is assessed,along with the challenges that must be overcome to realize this goal.

关键词： Hydrogel Thermogalvanic effect Thermochemistry Electrolytes Flexible electronics

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Anti-lymphangiogenesis for boosting drug accumulation in tumors

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Signal Transduction and Targeted Therapy 2024年第5期9卷 2161-2175页

作者： Chunling Wang Junchao Xu xiaoyu Cheng Ge Sun Fenfen Li Guangjun Nie Yinlong z.ang CAS Key Laboratory for Biomedical Effects of Nanomaterials&Nanosafety CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China Sino-Danish College University of Chinese Academy of SciencesBeijing 100190China Sino-Danish Center for Education and Research Beijing 100190China Department of Bioengineering University of PennsylvaniaPhiladelphiaPA 19104USA School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing 100049China

The inadequate tumor accumulation of anti-cancer agents is a major shortcoming of current therapeutic drugs and remains an even more significant concern in the clinical prospects for *** strategies aiming at regulating the intratumoral permeability of therapeutic drugs have been explored in preclinical studies,with a primary focus on vascular regulation and stromal ***,these methods may trigger or facilitate tumor metastasis as a ***,there is an urgent need for innovative strategies that boost intratumoral drug accumulation without compromising treatment *** another important factor affecting drug tumor accumulation besides vasculature and stroma,the impact of tumor-associated lymphatic vessels(LVs)has not been widely *** the current research,we verified that anlotinib,a tyrosine kinase inhibitor with anti-lymphangiogenesis activity,and SAR131675,a selective VEGFR-3 inhibitor,effectively decreased the density of tumor lymphatic vessels in mouse cancer models,further enhancing drug accumulation in tumor *** combining anlotinib with therapeutic drugs,including doxorubicin(Dox),liposomal doxorubicin(Lip-Dox),and anti-PD-L1 antibody,we observed improved anti-tumor efficacy in comparison with monotherapy ***,this strategy significantly reduced tumor metastasis and elicited stronger anti-tumor immune *** work describes a new,clinically transferrable approach to augmenting intratumoral drug accumulation,which shows great potential to address the current,unsatisfactory efficacies of therapeutic drugs without introducing metastatic risk.

关键词： drugs angiogenesis metastasis

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Interface catalytic reduction of alumina by nickle for the aluminum nanowire growth: Dynamics observed by in situ TEM

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Nano Research 2024年第3期17卷 1225-1231页

作者： zichun Wang Dan Wang ang Li Lizhuo Wang Xiaodong Han Yijiao Jiang Jianfeng Chen Jun Huang Beijing Advanced Innovation Center for Soft Matter Science and Engineering State Key Laboratory of Organic–Inorganic CompositesBeijing University of Chemical TechnologyBeijing 100029China Laboratory for Catalysis Engineering School of Chemical and Biomolecular EngineeringThe University of SydneyNew South Wales 2006Australia Beijing Key Laboratory of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100024China Department of Engineering Macquarie UniversitySydneyNew South Wales 2109Australia

Metal nanowires show promise in a broad range of applications and can be fabricated via a number of methods,such as vapor–liquid–solid process and template-based ***,the synthesis of Al nanowires(NWs)is still challenging from the stable alumina *** this work,the Ni-catalyzed fabrication of Al NWs has been realized using various Al_(2)O_(3) *** growth dynamics of Al NWs on Ni/Al_(2)O_(3) was studied using in situ transmission electron microscopy(TEM).The effect of alumina structures,compositions,and growth temperature were *** growth of Al NWs correlates with the Na addition to the alumina *** no eutectic mixture of nickel aluminide was formed,a mechanism of Ni-catalyzed reduction of Al_(2)O_(3) for Al NWs growth has been proposed instead of the vapor–liquid–solid *** key insights reported here are not restricted to Ni-catalyzed Al NWs growth but can be extended to understanding the dynamic change and catalytic performance of Ni/Al_(2)O_(3) under working conditions.

关键词： in situ transmission electron microscopy(TEM) Al nanowires alumina reduction nanowire growth

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X-ray excited Mn^(2+)-doped persistent luminescence materials with biological window emission for in vivo bioimaging

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Journal of Rare Earths 2024年第1期42卷 28-35,I0001页

作者： Hanrun zheng Lin Liu Yi’ang Li Rui Rong Liang Song Junpeng Shi Jing Teng Xia Sun Yun z.ang State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou350002China University of the Chinese Academy of Sciences Beijing100049China Xiamen Hospital of Traditional Chinese Medicine Xiamen361015China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou350108China

In recent years,persistent luminescence materials(PLMs)excited by X-rays and emitting in biological windows have received extensive attention in the field of high-sensitivity *** metal Mn^(2+)is an ideal emission center,but few studies focus on Mn^(2+)-doped PLMs with X-ray excitation and biological window ***,we report a Mn^(2+)-doped PLM,LiYGeO_(4):Mn^(2+)(LYGM),with excellent biological window persistent luminescence *** excitation by UV,LYGM produces a durable biological window of persistent luminescence emission at 660 nm for up to 20 *** *** can be repeatedly excited by X-rays,resulting in long-term biological window persistent luminescence *** addition,we obtain LYGM around 200 nm in diameter by ball milling and centrifugation and improve its biocompatibility by surface modification to apply it to in vivo imaging in *** LYGM are injected into mice through the tail vein,in situ excitation of X-rays can be *** the persistent luminescence decays,LYGM can be re-excited for repeated ***,LYGM shows potential prospects for in vivo deep tissue and long-term bioimaging.

关键词： Persistent luminescence X-ray Biological window In vivo imaging Rare earths

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Reconstructing cell lineage trees with genomic barcoding:approaches and applications

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Journal of Genetics and Genomics 2024年第1期51卷 35-47页

作者： ziz.ang Li Wenjing Yang Peng Wu Yuyan Shan xiaoyu z.ang Feng Chen Junnan Yang Jian-Rong Yang Advanced Medical Technology Center The First Affiliated HospitalZhongshan School of MedicineSun Yat-sen UniversityGuangzhouGuangdong 510080China Department of Genetics and Biomedical Informatics Zhongshan School of MedicineSun Yat-sen UniversityGuangzhouGuangdong 510080China Key Laboratory of Tropical Disease Control Ministry of EducationSun Yat-sen UniversityGuangzhouGuangdong 510080China

In multicellular organisms,developmental history of cell divisions and functional annotation of terminal cells can be organized into a cell lineage tree(CLT).The reconstruction of the CLT has long been a major goal in developmental biology and other related *** technological advancements,especially those in editable genomic barcodes and single-cell high-throughput sequencing,have sparked a new wave of experimental methods for reconstructing *** we review the existing experimental approaches to the reconstruction of CLT,which are broadly categorized as either image-based or DNA barcode-based *** addition,we present a summary of the related literature based on the biological insight pro-vided by the obtained ***,we discuss the challenges that will arise as more and better CLT data become available in the near *** barcoding-based CLT reconstructions and analyses,due to their wide applicability and high scalability,offer the potential for novel biological discoveries,especially those related to general and systemic properties of the developmental process.

关键词： Cell lineage tree Developmental regulation Biotechnology Computational biology

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