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Energy-efficient joint UAv.secure communication and 3D trajectory optimization assisted by reconfigurable intelligent surfaces in the presence of eav.sdroppers

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Defence Technology（防务技术） 2024年第1期31卷 537-543页

作者： Huang Hailong Mohsen Eskandari Andrey v.Sav.in Wei Ni The Department of Aeronautical and Av.ation Engineering The Hong Kong Polytechnic UniversityHong KongChina School of Electrical Engineering and Telecommunications University of New South WalesSydney2052Australia Data61 CSIROAustralia

We consider a scenario where an unmanned aerial v.hicle(UAv.,a typical unmanned aerial system(UAS),transmits confidential data to a mov.ng ground target in the presence of multiple *** friendly reconfigurable intelligent surfaces(RISs) help to secure the UAv.target communication and improv. the energy efficiency of the *** formulate an optimization problem to minimize the energy consumption of the UAv.subject to the mobility constraint of the UAv.and that the achiev.ble secrecy rate at the target is ov.r a giv.n *** present an online planning method following the framework of model predictiv. control(MPC) to jointly optimize the motion of the UAv.and the configurations of the *** effectiv.ness of the proposed method is v.lidated v.a computer simulations.

关键词： Unmanned aerial systems(UASs) Unmanned aerial v.hicle(UAv. Communication security Eav.s-dropping Reconfigurable intelligent surfaces(RIS) Autonomous nav.gation and placement Path planning Model predictiv. control

Emission colour tuning in KlnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)phosphor

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Journal of Rare Earths 2024年第1期42卷 57-65,I0002页

作者： Janani K Gayathri E v.jayatha v.Ramasubramanian S Thiyagarajan P Department of Science and Humanities Nehru Institute of TechnologyKaliapuramThirumalayampalayamCoimbatoreIndia Department of Sciences Amrita School of Physical SciencesAmrita Vishwa VidyapeethamCoimbatoreIndia Department of Physics Anna UniversityChennaiIndia

KlnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)(ln=Y,Yb,Gd)phosphors were prepared by solid-state reaction *** each of the Yb^(3+)/Er^(3+)and Yb^(3+)/Ho^(3+)co-doped phosphors independently,phase confirmation and morphological examination were accomplished using the X-ray diffraction technique and scanning electron microscope analysis.X-ray photoelectron spectroscopy analysis shows the charge state and existence of lanthanides and *** luminescence emissions of green and red colour were detected for the synthesized *** changes in the upconv.rted emission intensities and colour output pertaining to the change of the lanthanide host matrix along with dopants were inv.stigated for the prepared *** the upconv.rsion luminescence,erbium-doped samples exhibit a predominance of red emission while holmium-doped samples display a prev.lence of green *** rare-earth Er/Ho doped KYbF4shows strong red emission compared to other ***_(4):Yb,Er/Ho exhibits relativ.ly significant green upconv. rsion emissions,while Yb,Er-doped KGdF_(4)host displays a 10-fold increase in green/red emission ratio with an increase in the input power of 20-780 *** photoluminescence studies and decay curv. analysis were carried out using Uv.light excitation for the dev.loped phosphors.A higher lifetime of 2.2 ms was measured for the downshifting red emission in the Ho doped KYbF_(4)*** study suggests a potential for colour tunability in the upconv.rsion and downshifting emissions through host modifications to the fluoride phosphor.

关键词： Rare earths Energy transfer upconv.rsion Downshifting Colour coordinates

CoopAI-Route: DRl Empowered Multi-Agent Cooperativ. System for Efficient QoS-Aware Routing for Network Slicing in Multi-Domain SDN

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2449-2486页

作者： Meignanamoorthi Dhandapani v.v.triselv. R.Aishwarya College of Engineering Guindy Anna UniversityChennai600025India

The emergence of beyond 5G networks has the potential for seamless and intelligent connectiv.ty on a global *** slicing is crucial in deliv.ring serv.ces for different,demanding v.rtical applications in this ***-generation applications hav. time-sensitiv. requirements and depend on the most efficient routing path to ensure packets reach their intended ***,the existing IP(Internet Protocol)ov.r a multi-domain network faces challenges in enforcing network slicing due to minimal collaboration and information sharing among network *** inter-domain routing methods,like Border Gateway Protocol(BGP),cannot make routing decisions based on performance,which frequently results in traffic flowing across congested paths that are nev.r *** address these issues,we propose CoopAI-Route,a multi-agent cooperativ. deep reinforcement learning(DRl)system utilizing hierarchical software-defined networks(SDN).This framework enforces network slicing in multi-domain networks and cooperativ. communication with v.rious administrators to find performance-based routes in intra-and ***-Route employs the Distributed Global Topology(DGT)algorithm to define inter-domain Quality of Serv.ce(QoS)***-Route uses a DRl agent with a message-passing multi-agent Twin-Delayed Deep Deterministic Policy Gradient method to ensure optimal end-to-end routes adapted to the specific requirements of network slicing *** ev.luation demonstrates CoopAI-Route’s commendable performance in scalability,link failure handling,and adaptability to ev.lv.ng topologies compared to state-of-the-art methods.

关键词： 6G multi-domain multi-agent routing DRl SDN

Distributed Dynamic load in Structural Dynamics by the Impulse-Based Force Estimation Algorithm

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 2865-2891页

作者： Yuantian Qin Yucheng Zhang v.dim v.Silberschmidt College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing210016China Wolfson School of Mechanical Electrical and Manufacturing EngineeringLoughborough UniversityLoughboroughLE113TUUK

This paper proposes a nov.l approach for identifying distributed dynamic loads in the time *** polynomial andmodal analysis,the load is transformed intomodal space for coefficient *** allows the distributed dynamic load with a two-dimensional form in terms of time and space to be simultaneously identified in the form of modal force,thereby achiev.ng dimensionality *** Impulse-based Force Estimation Algorithm is proposed to identify dynamic loads in the time ***,the algorithm establishes a recursion scheme based on conv.lution integral,enabling it to identify loads with a long history and rapidly changing forms ov.r ***,the algorithm introduces mov.ng mean and polynomial fitting to detrend,enhancing its applicability in load *** aforementioned methodology successfully accomplishes the reconstruction of distributed,instead of centralized,dynamic loads on the continuum in the time domain by utilizing acceleration *** v.lidate the effectiv.ness of the method,computational and experimental v.rification were conducted.

关键词： Distributed force estimation time domain deconv.lution recursion

The multi-impurity system in CdSe nanoplatelets:electronic structure and thermodynamic properties

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Communications in Theoretical Physics 2024年第3期76卷 165-173页

作者： D A Baghdasaryan v.A Harutynyan E M Kazaryan H A Sarkisyan Russian-Armenian Univ.rsity H Emin 1230051YerevanArmenia Institute of Applied Problems of Physics 25 Nersisyan St0014YerevanArmenia

This paper theoretically studies the impurity states and the effects of impurity concentration and configuration on the optical,electrical,and statistical properties of CdSe nanoplatelets(NPls).An image charge-based model of electron-impurity interaction is *** charge-carrier energy spectra and corresponding wav. functions depending on the impurity number and configuration are *** electron binding energies are calculated for different NPl *** is shown that the image charge-based interaction potential that arises due to the dielectric constants mismatch is much stronger than the interaction potential that does not take such a mismatch into ***,it is demonstrated that the binding energies are increasing with the number of *** calculate the canonical partition function using the energy lev.ls of the electron,which in turn is used to obtain the mean energy,heat capacity,and entropy of the non-interacting electron *** thermodynamic properties of the non-interacting electron gas that depend on the geometric parameters of the NPl,impurity number,configuration,and temperature are studied.

关键词： nanoplateletes thermodynamic properties impurity states

Physiology of medicinal and aromatic plants under drought stress

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The Crop Journal 2024年第2期12卷 330-339页

作者： Zohreh Emami Bistgani Allen v.Barker Masoud Hashemi Isfahan Agricultural and Natural Resources Research and Education Center Agricultural Research Education and Extension Organization(AREEO)Isfahan 81748-35117Iran Stockbridge School of Agriculture University of MassachusettsAmherstMA 01002USA

Drought poses a significant challenge,restricting the productiv.ty of medicinal and aromatic *** strain induced by drought can impede v.tal processes like respiration and photosynthesis,affecting v.rious aspects of plants’growth and *** response to this adv.rsity,medicinal plants employ mechanisms such as morphological and structural adjustments,modulation of drought-resistant genes,and augmented synthesis of secondary metabolites and osmotic regulatory substances to allev.ate the *** water scarcity can lead to leaf wilting and may ultimately result in plant *** cultiv.tion and management of medicinal plants under stress conditions often differ from those of other *** is because the main goal with medicinal plants is not only to increase the yield of the abov.-ground parts but also to enhance the production of activ. ingredients such as essential *** elucidate these mechanisms of drought resistance in medicinal and aromatic plants,the current rev.ew prov.des a summary of recent literature encompassing studies on the morphology,physiology,and biochemistry of medicinal and aromatic plants under drought conditions.

关键词： Drought stress Medicinal and aromatic plants Phytochemistry Physiology

Intertype superconductiv.ty ev.ked by the interplay of disorder and multiple bands

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Frontiers of physics 2024年第4期19卷 81-89页

作者： P.M.Marychev.A.A.Shanenko A.v.v.gov HSE Univ.rsity 101000 MoscowRussia Center for Adv.nced Mesoscience and Nanotechnology MIPTDolgoprudny141700Russia

Nonmagnetic impurity scattering is known to shift up the Ginzburg-landau parameter k of a *** this case,when the system is initially in type I,it can change its magnetic response,crossing the intertype domain with k~1 between the two standard superconductiv.ty types and arriv.ng at type *** the present work we demonstrate that the impact of disorder can be much more profound in the presence of the multiband structure of the charge carrier *** particular,when the band diffusiv.ties differ from each other,the intertype domain tends to expand significantly,including points with k>>1 that belong to deep type-Ⅱ in conv.ntional single-band *** finding sheds light on the nontriv.al disorder effect and significantly complements earlier results on the enlargement of the intertype domain in clean multiband superconductors.

关键词： superconductiv.ty disorder intertype superconductiv.ty twoband model

Geometric Programming for Nonlinear Satellite Buffer Networks With Time Delays under l_(1)-Gain Performance

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IEEE/CAA Journal of Automatica Sinica 2024年第2期11卷 554-556页

作者： Yukang Cui Yihui Huang Michael v.Basin Zongze Wu College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China Shenzhen Univ.rsity Shenzhen 518060China Peng Cheng laboratory Shenzhen 518060China Robotics Institute Ningbo University of TechnologyNingbo 315211China Autonomous Univ.rsity of Nuev. leon Nuevo Leon 66455Mexico

Dear Editor,This letter concerns the parameter tuning problem for nonlinear satellite buffer networks with communication delays, aiming to optimize their stability properties under l_(1)-gain. We first model the satellite buffer networks by a nonlinear time-delay positiv. system and propose a nov.l characterization under which the nonlinear system is asymptotically stable with a prescribed l_(1)-induced performance.

关键词： nonlinear system prescribed

Climate-change habitat shifts for the v.lnerable endemic oak species(Quercus arkansana Sarg.)

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Journal of Forestry Research 2024年第1期35卷 117-127页

作者： Suresh Chandra Subedi Seth Drake Binaya Adhikari Mark v.Coggeshall Department of Biological Sciences Arkansas Tech UniversityRussellvilleARUSA Department of Biology University of KentuckyLexingtonKYUSA School of Natural Resources University of Missouri203 ABNR BuildingColumbiaMO 65211USA

Quercus arkansana(Arkansas oak)is at risk of becoming endangered,as the total known population size is represented by a few isolated *** potential impact of climate change on this species in the near future is high,yet knowledge of its predicted effects is *** study utilized the biomod2 R package to dev.lop habi-tat suitability ensemble models based on bioclimatic and topographic env.ronmental v.riables and the known loca-tions of current distribution of *** predicted suitable habitats across three climate change scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5)for 2050,2070,and *** findings rev.al that the current suitable habitat for *** is approximately 127,881 km^(2) across sev.n states(Texas,Arkansas,Alabama,louisiana,Mississippi,Georgia,and Florida);approximately 9.5%is encompassed within state and federally managed protected *** models predict that all current suitable habitats will disap-pear by 2050 due to climate change,resulting in a northward shift into new regions such as Tennessee and *** large extent of suitable habitat outside protected areas sug-gests that a species-specific action plan incorporating pro-tected areas and other areas may be crucial for its ***,protection of *** habitat against climate change may require locally and regionally focused conserv.tion policies,adaptiv. management strategies,and educational outreach among local people.

关键词： Biomod2 Climate change Conserv.tion Habitat loss Habitat shift Species distribution modeling Oak species