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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

Juv.nile surv.v.l curv.s in a solitary ground squirrel with a prolonged hibernation:effects of indiv.dual characteristics,env.ronment,and maternal inv.stment

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Current Zoology 2024年第1期70卷 13-23页

作者： Nina A.v.siliev. Liudmila E Sav.netskaya andrey v.Tchabov.ky A.N.Sev.rtsov.Institute of Ecology and Ev.lution Russian Academy of SciencesMoscow 119071Russia

Juv.nile surv.v.l is a key life-history influence on population dynamics and adaptiv. *** analyzed the effects of indiv.dual chara-cteristics,early env.ronment,and maternal inv.stment on juv.nile surv.v.l in a large solitary hibernating rodent-yellow ground squirrel Spermophilus fulv.s using Cox mixed-effects *** 48%of weaned pups surv.v.d to dispersal and 17%surv.v.d to *** life expectancy was primarily determined by indiv.dual characteristics and,to a lesser extent,by the early *** strongest and pos-itiv. predictor of juv.nile surv.v.l was body mass which crucially affected mortality immediately after *** suffered higher mortality than females after the onset of dispersal;howev.r,the ov.rall difference between sexes was partly masked by high rates of mortality in the first days after emergence in both *** emerged juv.niles had lower life expectancy than the earliest *** ov.rall effect of local juv.nile density was *** lactation did not enhance juv.nile surv.v.l:Pups nursed longer surv.v.d shorter than the young nursed for a shorter *** findings support the hypothesis that females of *** cannot effectiv.ly regulate maternal expenditures to mitigate the effects of unfav.rable 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 juv.nile quality and *** female reproductiv. strategy corresponds to a"fast-solitary"life of foliv.rous desert-dwelling *** and other solitary ground squirrels with prolonged hibernation.

关键词： early-life conditions ground squirrels hibernation juv.nile mortality maternal inv.stment surv.v.l curv.s

Exploring v.n 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.Slav.ch Georgy A.Ermolaev.Mikhail K.Tatmyshev.kiy Adilet N.Toksumakov.Olga G.Matv.ev. Dmitriy v.Grudinin Kirill v.v.ronin Arslan Mazitov.Konstantin v.Krav.sov.Alexander v.Syuy Dmitry M.Tsymbarenko Mikhail S.Mironov.Sergey M.Nov.kov.Iv.n Kruglov.Dav.t A.Ghazaryan andrey A.v.shnev.y Aleksey v.Arsenin v.lentyn S.v.lkov.Kostya S.Nov.selov Moscow Center for Adv.nced 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 Adv.nced 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 v.n der Waals(v.W)materials resulted in the discov.ry of their high optical,mechanical,and electronic anisotropic properties,immediately enabling countless nov.l phenomena and *** success inspired an intensiv. search for the highest possible anisotropic properties among v.W ***,the identification of the most promising among the huge family of v.W materials is a challenging quest requiring innov.tiv. ***,we suggest an easy-to-use method for such a surv.y based on the crystallographic geometrical perspectiv. of v.W materials followed by their optical *** our approach,we found As2S3 as a highly anisotropic v.W *** demonstrates high in-plane optical anisotropy that is~20%larger than for rutile and ov.r two times as large as calcite,high refractiv. index,and transparency in the v.sible range,ov.rcoming the century-long record set by *** these benefits,As2S3 opens a pathway towards nextgeneration nanophotonics as demonstrated by an ultrathin true zero-order quarter-wav. plate that combines classical and the Fabry–Pérot optical phase ***,our approach prov.des an effectiv. and easy-to-use method to find v.W materials with the utmost anisotropic properties.

关键词： anisotropy anisotropic high

Studies of ultrasonic dehydration efficiency

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Journal of Zhejiang Univ.rsity-Science A(Applied Physics & Engineering) 2011年第4期12卷 247-254页

作者： v.adimir N. KHMELEv.andrey v. SHALUNOv.Roman v. BARSUKOv.Denis S. ABRAMENKO andrey N. LEBEDEv Biysk Technological Institute (Branch) Altai State Technical Univ.rsity

The aim of this inv.stigation was to define the effectiv.ness of non-contact drying using ultrasonic v.brations. Disk radiators were used for carrying out experiments, and a special drying chamber was designed to prov.de resonant amplification of ultrasonic v.brations (from 130 to 150 dB). Drying of ginseng and other v.getables demonstrated that the application of ultrasonic v.brations reduced power inputs by 20% in comparison with conv.ctiv. drying. It also led to a decrease of 6% in final moisture content, if the duration of drying was constant. The lev.l of intensification of ultrasonic drying was high (up to 50 g for 1 kg of drying material), which helped to lower the temperature of the drying agent and improv. the quality of the dried products.

关键词： Drying Ultrasound v.bration system Drying chamber Processing (treatment) of agricultural products

Age of maturation and behav.oral tactics in male yellow ground squirrel Spermophilus fulv.s during mating season

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Current Zoology 2014年第6期60卷 700-711页

作者： Nina A. v.SILIEv. Ekaterina v. PAv.Ov. Sergey v. NAIDENKO andrey v.TCHABOv.KY A.N. Sev.rtsov.Institute of Ecology and Ev.lution Russian Academy of Sciences 33 Leninsky pr. Moscow 119071 Russia

Life-history theory predicts that in hibemators age of maturation is related positiv.ly to body size and negativ.ly to the duration of activ. season abov.ground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observ.tions of marked indiv.duals to determine the age of maturation in males through analysis of age-dependent v.riation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behav.or during the mating season. Yearling males were smaller, lighter, had lower lev.l of fecal testosterone, emerged later and had smaller home ranges than older males. Social activ.ty and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters v.ried with age. Cluster analysis rev.aled two behav.oral tactics：＂activ.＂ males （adults only） emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heav.er than ＂passiv.＂ males （both yearling and adult）. Thus, males of S. fulv.s reached adult size and matured after two hibernations, which is relativ.ly fast for such a big species with short activ. period. Indirect ev.dence for copulations and high v.riation among yearlings in all parameters suggest that some of them might successfully compete with adults. Activ. tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passiv. tactic of residing is energy sav.ng and good for adults in poor condition and for yearlings that are continuing to grow.

关键词： Age of maturation Mating system Reproductiv. tactics Ground squirrel Spermophilusfulv.s

Microperforation of the human nail plate by radiation of erbium lasers

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Frontiers of Optoelectronics 2017年第3期10卷 299-307页

作者： andrey v. BELIKOv.andrey N. SERGEEv.Sergey N. SMIRNOv.Anastasia D. TAv.LINSKAYA Department of Laser Technologies and Systems Saint-Petersburg National Research University of Information Technologies Mechanics and Optics (ITMO University) Saint Petersburg 197101 Russia

The nail plate forms a barrier that limits the effectiv.ness of drug deliv.ry in the treatment of nail diseases and prev.nts the outflow of fluid in the case of subungual hematoma formation. Microperforation of the nail plate through laser radiation can increase the effectiv.ness of drug deliv.ry and ensure the possibility of blood outflow. This study detected and identified the type and threshold of effects that arise from exposing the nail plate to Yb,Er： Glass （λ = 1.54 μm） and Er：YLF （λ= 2.81 μm） laser radiation. The rate and efficiency of nail plate ablation by the radiation of these lasers were studied. The effect of the storage time of a freshly extracted nail plate in open air on its ablation rate by Er：YLF （ λ=2.81 μm） laser radiation was also inv.stigated. The impact of the Yb,Er：Glass and Er：YLF laser pulses on the nail plate caused bleaching, carbonization, ablation with microcrater formation, and microperforation. The laser energy densities WE （thresholds） required for these effects were determined. The maximum ablation rate for Yb,Er：Glass laser radiation was 8 μm/pulse at WE = 91 ±2 J/cm2, whereas that for Er：YLF laser radiation was 12 μm/ pulse at WE= 10.5＋0.5 J/cm2. The maximum ablation efficiency for Yb,Er：Glass laser radiation was 0.1 μm/mJ at Ws = 10.5±0.5 J/cm2, whereas that for Er：YLF laser radiation was 4.6 μm/mJ at WE = 5.3±0.3 J/cm2. The laser ablation rate depends on the storage time and conditions of the freshly extracted nail plate. For example, when exposed to Er：YLF laser radiation, the laser ablation rate decreased by half from the initial maximum v.lue in 96 h of air storage and returned to the initial v.lue after 1 h of storage in distilled water.

关键词： Yb Er:Glass laser Er:YLF laser nail plate microperforation ablation rate ablation efficiency dehydration

Nucleation of methane hydrate and ice in emulsions of water in crude oils and decane under non-isothermal conditions

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Chinese Journal of Chemical Engineering 2019年第3期27卷 668-676页

作者： andrey S. Stoporev.Lidiya I. Sv.rov.kaya Larisa A. Strelets Lubov. K. Altunina Galina v. v.llev.ld Tamara D. Karpov. Tatyana v. Rodionov. andrey Yu. Manakov Nikolaev.Institute of Inorganic Chemistry SB RAS Nov.sibirsk State Univ.rsity Institute of Petroleum Chemistry

Achiev.ble supercooling for the formation of methane hydrate from water emulsions was studied in sev.n different crude oils and in decane. The experiments were performed under constant rate cooling from + 20 to-15 °C and a pressure of methane of 12 MPa. It was demonstrated that the shapes and positions of the resulting surv.v.l curv.s depend on the density, v.scosity and dispersiv. power of oil samples used in the experiments, as well as on the degree of oil oxidation. In addition, results of the experiments on ice freezing under the same emulsions are presented. The results obtained in the work allowed us to discuss the possibility and features of primary and secondary nucleation of the hydrate and ice in the systems under consideration.

关键词： Methane hydrate Crude oil Oil dispersiv. system Nucleation

Bistable lasing in parity-time symmetric coupled fiber rings

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Photonics Research 2018年第4期6卷 I0018-I0022页

作者： SERGEY v. SMIRNOv.MAXIM O. MAKARENKO SERGEY v. SUCHKOv.DMITRY CHURKIN andrey A. SUKHORUKOv Nov.sibirsk State Univ.rsity 2 Pirogova Street Novosibirsk 630090 Russia Nonlinear Physics Centre Research School of Physics and Engineering Australian National University Canberra ACT 2601 Australia

We propose a parity-time(PT) symmetric fiber laser composed of two coupled ring cav.ties with gains and losses,which operates both in PT-symmetric and symmetry-broken regimes depending on the static phase shifts. We perform analytical and numerical analysis by the transfer matrix method taking into account gain saturation and predict laser bistability in the PT-symmetric regime in contrast to a symmetry-broken single-mode *** the PT-broken regime, the generation power counterintuitiv.ly increases with an increase of the cav.ty losses.

关键词：光纤激光器奇偶时间激光双稳态通讯技术

Synthesis of cyclic carbonates from epoxides or olefins and CO_2 catalyzed by metal-organic frameworks and quaternary ammonium salts

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Journal of Energy Chemistry 2013年第1期22卷 130-135页

作者： Olga v. Zalomaev. Nataliya v. Maksimchuk andrey M. Chibiryaev.Konstantin A. Kov.lenko v.adimir P. Fedin Bair S. Balzhinimaev Boreskov.Institute of Catalysis pr. Akademika Lavrentieva 5 v.rozhtsov.Nov.sibirsk Institute of Organic Chemistry pr Akademika Lavrentieva 9 Nikolaev.Institute of Inorganic Chemistry pr. Akademika Lavrentieva 3

Catalytic properties of the metal-organic framework Cr-MIL-101 in solv.nt-free cycloaddition of CO2 to epoxides to produce cyclic carbon- ates using tetrabutylammonium bromide as co-catalyst hav. been explored under mild reaction conditions （8 bar CO2, 25 ~C）. Styrene and propylene carbonates were formed with high yields （95% and 82%, respectiv.ly）. Catalytic performance of Cr-MIL-101 was compared with other MOFs： Fe-MIL-101, Zn-MOF-5 and HKUST-1, The catalytic properties of different quaternary ammonium bromides, Cr-MIL-101 as well as PW12/Cr-MIL-101 composite material hav. been assessed in oxidativ. carboxylation of styrene in the presence of both tert-butyl hydroperoxide and H202 as oxidants at 8-100bar CO2 and 25-80 ~C with selectiv.ty to styrene carbonate up to 44% at 57% substrate conv.rsion.

关键词： carbon dioxide cyclic carbonates cycloaddition heterogeneous catalysis metal-organic framework oxidativ. carboxylation quaternary am-monium salts