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

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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.Savkin Wei Ni The Department of Aeronautical and Aviation 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 vehicle(UAv),a typical unmanned aerial system(UAS),transmits confidential data to a moving ground target in the presence of multiple *** friendly reconfigurable intelligent surfaces(RISs) help to secure the UAv-target communication and improve 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 achievable secrecy rate at the target is over a given *** present an online planning method following the framework of model predictive control(MPC) to jointly optimize the motion of the UAv and the configurations of the *** effectiveness of the proposed method is validated via computer simulations.

关键词： Unmanned aerial systems(UASs) Unmanned aerial vehicle(UAv) Communication security Eaves-dropping Reconfigurable intelligent surfaces(RIS) Autonomous navigation and placement Path planning Model predictive control

Juvenile survival curves in a solitary ground squirrel with a prolonged hibernation:effects of individual characteristics,environment,and maternal investment

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Current Zoology 2024年第1期70卷 13-23页

作者： Nina A.vasilieva Liudmila E Savinetskaya andrey v.Tchabovsky A.N.Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscow 119071Russia

Juvenile survival is a key life-history influence on population dynamics and adaptive *** analyzed the effects of individual chara-cteristics,early environment,and maternal investment on juvenile survival in a large solitary hibernating rodent-yellow ground squirrel Spermophilus fulvus using Cox mixed-effects *** 48%of weaned pups survived to dispersal and 17%survived to *** life expectancy was primarily determined by individual characteristics and,to a lesser extent,by the early *** strongest and pos-itive predictor of juvenile survival was body mass which crucially affected mortality immediately after *** suffered higher mortality than females after the onset of dispersal;however,the overall difference between sexes was partly masked by high rates of mortality in the first days after emergence in both *** emerged juveniles had lower life expectancy than the earliest *** overall effect of local juvenile density was *** lactation did not enhance juvenile survival:Pups nursed longer survived shorter than the young nursed for a shorter *** findings support the hypothesis that females of *** cannot effectively regulate maternal expenditures to mitigate the effects of unfavorable conditions on their *** strategy to deal with seasonal time constraints on life history in female *** suggests an early termination of maternal care at the cost of juvenile quality and *** female reproductive strategy corresponds to a"fast-solitary"life of folivorous desert-dwelling *** and other solitary ground squirrels with prolonged hibernation.

关键词： early-life conditions ground squirrels hibernation juvenile mortality maternal investment survival curves

Exploring van der Waals materials with high anisotropy:geometrical and optical approaches

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Light(Science & Applications) 2024年第4期13卷 645-653页

作者： Aleksandr S.Slavich Georgy A.Ermolaev Mikhail K.Tatmyshevskiy Adilet N.Toksumakov Olga G.Matveeva Dmitriy v.Grudinin Kirill v.voronin Arslan Mazitov Konstantin v.Kravtsov Alexander v.Syuy Dmitry M.Tsymbarenko Mikhail S.Mironov Sergey M.Novikov Ivan Kruglov Davit A.Ghazaryan andrey A.vyshnevyy Aleksey v.Arsenin valentyn S.volkov Kostya S.Novoselov Moscow Center for Advanced Studies Kulakova str.20Moscow 123592Russia. Emerging Technologies Research Center XPANCEOInternet CityEmmay TowerDubaiUnited Arab Emirates. Donostia International Physics Center(DIPC) Donostia/San-Sebastián 20018Spain. Institute of Materials Ecole Polytechnique Federale de Lausanne1015 LausanneSwitzerland. Department of Chemistry Lomonosov Moscow State UniversityMoscow 119991Russia. Laboratory of Advanced Functional Materials Yerevan State UniversityYerevan 0025Armenia. National Graphene Institute(NGI) University of ManchesterManchester M139PLUK. Department of Materials Science and Engineering National University of SingaporeSingapore 03-09 EASingapore. Institute for Functional Intelligent Materials National University of Singapore117544 SingaporeSingapore

The emergence of van der Waals(vdW)materials resulted in the discovery of their high optical,mechanical,and electronic anisotropic properties,immediately enabling countless novel phenomena and *** success inspired an intensive search for the highest possible anisotropic properties among vdW ***,the identification of the most promising among the huge family of vdW materials is a challenging quest requiring innovative ***,we suggest an easy-to-use method for such a survey based on the crystallographic geometrical perspective of vdW materials followed by their optical *** our approach,we found As2S3 as a highly anisotropic vdW *** demonstrates high in-plane optical anisotropy that is~20%larger than for rutile and over two times as large as calcite,high refractive index,and transparency in the visible range,overcoming the century-long record set by *** these benefits,As2S3 opens a pathway towards nextgeneration nanophotonics as demonstrated by an ultrathin true zero-order quarter-wave plate that combines classical and the Fabry–Pérot optical phase ***,our approach provides an effective and easy-to-use method to find vdW materials with the utmost anisotropic properties.

关键词： anisotropy anisotropic high

Autonomous UAv 3D trajectory optimization and transmission scheduling for sensor data collection on uneven terrains

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Defence Technology（防务技术） 2023年第12期30卷 154-160页

作者： andrey v.Savkin Satish C.verma Wei Ni School of Electrical Engineering and Telecommunications University of New South WalesSydneyAustralia Data61 CSIROCanberraACT2601Australia

This paper considers a time-constrained data collection problem from a network of ground sensors located on uneven terrain by an Unmanned Aerial vehicle(UAv),a typical Unmanned Aerial System(UAS).The ground sensors harvest renewable energy and are equipped with batteries and data *** ground sensor model takes into account sensor data buffer and battery *** asymptotically globally optimal method of joint UAv 3D trajectory optimization and data transmission schedule is *** developed method maximizes the amount of data transmitted to the UAv without losses and too long delays and minimizes the propulsion energy of the *** developed algorithm of optimal trajectory optimization and transmission scheduling is based on dynamic *** simulations demonstrate the effectiveness of the proposed algorithm.

关键词： Unmanned aerial system UAS Unmanned aerial vehicle UAv Wireless sensor networks UAS-Assisted data collection 3D trajectory optimization Data transmission scheduling

Substituted diamides of dipicolinic acid as extractants and ionophores for rare earth metals

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Journal of Rare Earths 2023年第8期41卷 1234-1241,I0005页

作者： Yingchao Ren valery A.Polukeev Ekaterina v.Kenf Liudmila I.Tkachenko Mikhail Yu Alyapyshev vasily A.Babain andrey v.Nechaev andrey v.Legin Dmitry O.Kirsanov Institute of Chemistry Saint-Petersburg UniversityPeterhofUniversitetsky Prospect 26198504Saint-PetersburgRussia JSvC vekton Ul.2-oy Luch 9192019Saint-PetersburgRussia Khlopin Radium Institute 194021282nd Murinsky avRussia ThreeArc Mining LLC Pr.Narodnogo Opolchenia 10198216Saint-PetersburgRussia Rusredmet Vosstanovleniya str.15bl.3198320St.PeterburgKrasnoe seloRussia

The variety of newly synthesized diamides of dipicolinic acid(DPA)bearing methyl-and oxymethyl substituents in various positions of phenyl ring was investigated as potential ligands for liquid-liquid extraction of rare earth metal ions and as membrane active compounds in plasticized polymeric membranes of potentiometric *** is found that scandium is extracted with 2,6-pyridinedicarboxylic acid diamides similarly to heavy lanthanides,while yttrium is extracted together with light group *** shows high selectivity for the separation of cadmium/zinc,lead/nickel or copper/nickel *** four out of six studied ligands demonstrate significant potentiometric sensitivity towards scandium,yttrium and lanthanides in 10^(-7)-10^(-3)mol/L concentration range in nitric acid *** trends in sensitivity values vary depending on a ligand structure and the highest values are observed for Sc^(3+)and heavy *** to the evaluated selectivity Sm^(3+)is the most preferred ion,while La^(3+)is the most *** differences in sensor behavior in rare earth metal solutions assume that such devices can be applied in sensor arrays for potentiometric analysis of lanthanide mixtures.

关键词： Dipicolini cacid diamides Scandium Yttrium Lanthanides Extraction Potentiometric sensors

Neuromorphic nanocluster networks:Critical role of the substrate in nano-link formation

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Nano Research 2023年第7期16卷 10500-10506页

作者： Wenkai Wu Alexey v.verkhovtsev Theodoros Pavloudis andrey v.Solov’yov Richard E.Palmer Nanomaterials Lab Faculty of Science and EngineeringSwansea UniversityBay CampusFabian WaySA18ENSwanseaUK MBN Research Center Altenhöferallee 360438 Frankfurt am MainGermany School of Physics Faculty of SciencesAristotle University of ThessalonikiGR-54124 ThessalonikiGreece

Atomic cluster-based networks represent a promising architecture for the realization of neuromorphic computing systems,which may overcome some of the limitations of the current computing *** formation and breakage of links between the clusters are of utmost importance for the functioning of these computing *** paper reports the results of molecular dynamics simulations of synapse(bridge)formation at elevated temperature and thermal breaking processes between 2.8 nmsized Au1415 clusters deposited on a carbon substrate,a model ***,we find that the bridge formation process is driven by the diffusion of gold atoms along the substrate,no matter how small the gap between the clusters *** complementary simulations of the bridge breaking process reveal the existence of a threshold bias voltage to activate bridge rupture via Joule *** results provide an atomistic-level understanding of the fundamental dynamical processes occurring in neuromorphic cluster arrays.

关键词： atomic-switch network nanoclusters nanoparticles(NPs) clusters on surfaces synapse neuromorphics molecular dynamics(MD)

Efficient passivation of DY center in CH_(3)NH_(3)PbBr_(3) by chlorine:Quantum molecular dynamics

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Nano Research 2022年第3期15卷 2112-2122页

作者： Ran Shi Wei-Hai Fang andrey S.vasenko Run Long Oleg v.Prezhdo College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing 100875China National Research University Higher School of Economics(HSE)University 101000 MoscowRussia Donostia International Physics Center(DIPC) Paseo Manuel de Lardizabal 4San Sebastián/Donostia20018 Basque CountrySpain Department of Chemistry University of Southern CaliforniaLos AngelesCA 90089USA

MAPbBr_(3)(MA=CH_(3)NH_(3)^(+))doping with bismuth increases electric conductivity,charge carrier density and photostability,reduces toxicity,and expands light ***,Bi doping shortens excited-state lifetimes due to formation of DY−charge recombination *** nonadiabatic molecular dynamics and time-domain density functional theory,we demonstrate that the DY−center forms a deep,highly localized hole trap,which accelerates nonradiative relaxation ten-fold and is responsible for 90%of carrier *** trapping occurs by coupling between the valence band and the trap state,facilitated by the Br atoms surrounding the Bi *** of the DY−center with chlorines heals the local geometry distortion,eliminates the trap state,and makes the carrier lifetimes longer than even in pristine MAPbBr_(3).The decreased charge recombination arises from reduced nonadiabatic coupling and shortened coherence time,due to diminished electron–hole overlap around the passivated *** study demonstrates accelerated nonradiative recombination in Bi-doped MAPbBr_(3),suggests a strategy for defect passivation and reduction of nonradiative energy losses,and provides atomistic insights into unusual defect properties of metal halide perovskites needed for rational design of high-performance perovskite solar cells and optoelectronic devices.

关键词： Hybrid organic-inorganic perovskite DY−center and Cl passivation charge trapping and recombination nonadiabatic molecular dynamics time-domain density functional theory.

Evolution of metabolic scaling among the tetrapod:effect of phylogeny,the geologic time of class formation,and uniformity of species within a class

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Integrative Zoology 2022年第5期17卷 904-917页

作者： valery M.GAvRILOv Tatiana B.GOLUBEvA andrey v.BUSHUEv Department of vertebrate Zoology M.V.Lomonosov Moscow State UniversityMoscowRussia Zvenigorod Biological Station M.V.Lomonosov Moscow State UniversityMoscowRussia

The metabolic scaling in the animal has been discussed for over 90 years,but no consensus has been *** analysis of 2126 species of vertebrates reveals a signiﬁcant allometric exponent *** show that classes of terrestrial vertebrates exhibit the evolution of metabolic *** the allometric coefﬁcient“a”and the allometric exponent“b”change naturally,but differently depending on the geological time of group *** allometric coefﬁcient“a”shows the measure of the evolutionary development of systems that forms resting metabolism in *** classes,such as birds and mammals,have a metabolic rate that is in an order of magnitude higher than that in ectothermic classes,including amphibians and *** the terrestrial vertebrate phylogeny,weﬁnd that the metabolic scaling is characterized by 3 main allometric exponent values:b=3/4(mammals),b>3/4(ectotherms,such as amphibians and reptiles),and bvolution of *** scaling factor decreases depending on both the external design and the size(birds vs mammals)of the *** metabolic rate and uniformity of species within a class increase as the geological start date of for-mation of the class approaches the present *** higher the mass-speciﬁc standard metabolic rate in the class,the slower metabolic rate grows with increasing body size in this *** results lay the groundwork for further exploration of the evolutionary and ecological aspects of the development of metabolic scaling in animals.

关键词： geological time metabolic rate scaling

Highly efficient transient stimulated Raman scattering on secondary vibrational mode of BaWO_(4) crystal due to its constructive interference with self-phase modulation

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Chinese Optics Letters 2023年第3期21卷 113-117页

作者： Igor Kinyaevskiy valeri Kovalev Pavel Danilov Nikita Smirnov Sergey Kudryashov andrey Koribut andrey Ionin P.N.Lebedev Physical Institute of the Russian Academy of Sciences Moscow 119991Russia

An exceptionally high stimulated Raman scattering[SRS]conversion efficiency to the first Stokes component associated with the secondary[low-frequency and low intensity]vibrational mode v2[~330 cm^[-1]]was observed in a BaWO4 crystal in a highly transient regime of *** effect takes place in the range of pump pulse energy from~0.1 to~0.5μJ with maximum energy conversion efficiency up to 35%at 0.2μ*** nature of the observed effects is explained by interference of SRS and self-phase modulation,where the latter is related to a noninstantaneous orientational Kerr nonlinearity in the BaWO4 crystal.

关键词： stimulated Raman scattering secondary vibrational mode self-phase modulation ultrashort laser pulses transient phenomena