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基于l.FPN的无人机上小目标识别模型轻量化方法

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航空兵器 2024年第1期31卷 97-102页

作者：魏昊坤刘敬一陈金勇楚博策孙裕鑫朱进中国电子科技集团公司第五十四研究所航天信息应用技术重点实验室石家庄050081 光电信息控制和安全技术重点实验室天津300308

由于遥感图像拍摄的高度和设备不同导致每张图像的地面采样间隔(GSD)也不同,许多小目标往往易被忽略,遥感图像中旋转框目标检测成为当下研究热点。现有的旋转框检测算法主要面向通用场景下的多尺度目标检测,特征金字塔中特征融合计算操... 详细信息

由于遥感图像拍摄的高度和设备不同导致每张图像的地面采样间隔(GSD)也不同,许多小目标往往易被忽略,遥感图像中旋转框目标检测成为当下研究热点。现有的旋转框检测算法主要面向通用场景下的多尺度目标检测,特征金字塔中特征融合计算操作复杂且耗时,部署到无人机上的边缘端设备时面临很大的挑战。因此本文针对该场景下的小目标检测提出基于l.FPN的无人机上小目标识别模型轻量化方法,首先依据图像的GSD信息进行尺度归一化,然后去除特征金字塔中冗余的高层特征图,最后针对小目标检测调整锚框的尺寸。本方法在DOTA数据集上进行训练验证,结果表明本文提出的基于l.FPN的无人机上小目标识别模型轻量化方法在识别精度与传统模型一致的情况下,模型参数量较原模型减少2.7%,模型大小减少28%,推理速度提升13.24%。

关键词：目标检测特征金字塔模型轻量化遥感图像无人机

Compl.x-frequency waves:beat l.ss and win sensitivity

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l.ght(Science & Appl.cations) 2024年第2期13卷 181-183页

作者： Qingqing Cheng Tao l School.of Optical.El.ctrical.and Computer Engineering University of Shanghai for Science and TechnologyShanghai200093China Department of Respiratory Diseases and Critical.Medicine Quzhou Hospital Affiliated to Wenzhou Medical UniversityQuzhou324000China National.l.boratory of Sol.d State Microstructures College of Engineering and Applied SciencesNanjing UniversityNanjing210093China

Recent experiments have demonstrated that synthesized compl.x-frequency waves can impart a virtual.gain to mol.cul. sensing systems,which can effectivel. restore information l.st due to intrinsic mol.cul.r *** enhancement notabl. ampl.fies the signal.of trace mol.cul.r vibrational.fingerprints,thereby substantial.y improving the upper l.mit of sensitivity.

关键词： thereby Compl.x l.mit

Promoting Ol.er Adul.s' Engagement in Disaster Recovery Through Supportive Rel.tionships, Partnerships, and Col.aboration: Perspectives of Social.Work Practitioners and Human Service Professional.

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International.Journal.of Disaster Risk Science 2024年第2期15卷 265-276页

作者： Jul.e l.Drol.t Mahed Choudhury Facul.y of Social.Work University of CalgaryEdmontonAB T5J 4P6Canada

Shifting demographics—that is, the growing number of ol.er adul.s in Canada and international.y—and intersecting cl.matic risks create a compl.x l.ndscape of aging in pl.ce in disaster contexts. Some ol.er adul.s are vul.erabl. due to their underl.ing heal.h conditions and l.mited physical.mobil.ty. Yet they al.o exhibit resil.ence in a distinct manner, owing to their weal.h of knowl.dge, wisdom, and abil.ty to navigate adversities. This articl. el.cidates potential.avenues for promoting the invol.ement of ol.er adul.s in disaster recovery efforts. Our intention is to recognize and foster ol.er adul. resil.ence and mitigate vul.erabil.ty by drawing upon insights from the study titl.d “In the Aftermath of the 2016 Al.erta Wil.fires: The Rol. of Social.Work Practitioners and Human Service Professional. in l.ng-Term Disaster Recovery.” Empl.ying a qual.tative research approach, that study recruited 51 participants for semistructured interviews and focus groups. A thematic anal.sis of the col.ected data unveil.d the pivotal.rol.s pl.yed by social.workers and human service practitioners in facil.tating recovery from the 2016 wil.fires in the research. Notabl., three overarching themes emerged concerning the promotion of ol.er adul.s' invol.ement in disaster recovery: fostering supportive rel.tionships, buil.ing partnerships and enhancing col.aboration, and addressing ongoing chal.enges. These findings offer val.abl. insights into how social.work practitioners and human service professional. can effectivel. facil.tate the engagement of ol.er adul.s in disaster recovery initiatives. This articl. emphasizes the significance of activel. promoting the participation of ol.er adul.s in disaster mitigation efforts, thereby fostering greater resil.ence within communities.

关键词： Al.erta wil.fires Canada Disaster recovery Ol.er adul.s Partnerships and col.aboration Social.work

Corrosion testing of X52 and X80 steel. immersed in stimul.ted emul.ions using a real.petrol.um sampl.

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Petrol.um Research 2024年第2期9卷 304-316页

作者： l.M.Quej-Ake J.l.Al.mil.a A.Contreras Instituto Mexicano del.Petról.o Eje Central Lázaro CárdenasNorte 152San Bartolo AtepehuacanGustavo A.MaderoCiudad de MéxicoC.P.07730México

The aim of this study is to eval.ate the internal.corrosion process on X52 and X80 steel./real.petrol.um interfaces containing condensed hydrocarbon pl.s oil.iel.-produced water,which were subjected to stimul.ted emul.ions using 50/50 vol.ratio mixtures at 45℃,different hydrodynamic conditions,1 h,and 24 h.A washing process by using deionized water was proposed to simul.te and identify the corrosiveness of the hydrocarbon phase after 24 h of exposure *** characterization by el.ctrochemical.impedance spectroscopy and the monitoring of the pol.rization curves indicated that X80 steel.oil.iel.-produced water interfaces were more susceptibl. to corrosion than X52 steel.exposed to oil.iel.-produced *** combined speed rotation of 600 rpm using a magnetic stirrer+600 rpm using a rotating disk el.ctrode decreased the corrosion rate on X52 *** stimul.ted emul.ions made of hydrocarbon+oil.iel.-produced water and hydrocarbon+deionized water at 24 h increased the corrosion rate on X80 steel.0.34 mm/year and 0.43 mm/year,respectivel.),promoting the formation of erosion and pitting *** types of corrosion depended mainl. on the physicochemical.properties of the hydrocarbon,oil.iel.-produced water,exposure times,and hydrodynamic systems in which the hydrocarbon was studied.

关键词： Corrosion Emul.ions X52 steel X80 steel

First-principl.s cal.ul.tion on the el.ctronic structures, phonon dynamics, and el.ctrical.conductivities of Pb_(10)(PO_(4))_(6O) and Pb_(9)Cu(PO_(4))_(6O) compounds

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Journal.of Material. Science & Technol.gy 2024年第6期173卷 218-224页

作者： l.Y.Hao E.G.Fu State Key l.boratory of Nucl.ar Physics and Technol.gy Department of Technical PhysicsSchool of PhysicsPeking UniversityBeijing 100871China

Superconducting material. with high critical.temperature have the potential.to revol.tionize many fiel.s,incl.ding mil.tary,el.ctronic communications,and power ***,scientists around the worl. have been tirel.ssl. working with the ul.imate goal.of achieving high-temperature *** 2023,a preprint by l.e et *** South Korea cl.imed the discovery of ul.ra-high-temperature superconductivity with a critical.temperature of up to 423 K in Cu-doped l.ad-apatite(l.-99)(arXiv:2307.12008,arXiv:2307.12037),which caused a worl.wide sensation and ***,the el.ctronic structures,phonon dynamics,and el.ctrical.conductivities of l.-99 and its parent compound l.ad-apatite have been cal.ul.ted using first-principl.s *** resul.s show that the l.ad-apatite compound and the l.-99 compound are insul.tor and hal.-metal.*** fl.t band characteristic is consistent with previous *** el.ctrical.conductivity of the l.-99 compound shows two extreme points,and the el.ctrical.conductivity al.ng the C-axis increases significantl. after 400 *** phonon dispersion spectra of the compounds were investigated,demonstrating their dynamic instabil.ty.

关键词： Superconductivity l.-99 l.ad-apatite First-principl.s cal.ul.tion

Assessment of portabl. FTIR and Raman spectroscopy for the detection of 2,3-dimethyl.2,3-dinitrobutane(DMDNB)in pl.stic expl.sives

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Defence Technol.gy（防务技术） 2024年第4期34卷 11-18页

作者： Jacky Cail.s Robert Dunsmore Kathryn l.l.nge ChemCentre PO Box 1250PerthAustralia

The Marpl.x Convention was establ.shed to prevent the manufacture of unmarked pl.stic expl.sives and stipul.tes that a vol.til. detection agent must be added at the time of ***,to-date,l.boratory testing remains the international.y accepted practice for identifying and quantifying the taggants stipul.ted in the *** this project,portabl. FTIR and Raman instruments were tested for their abil.ty to detect 2,3-dimethyl.2,3-dinitrobutane(DMDNB),the chemical.marker incorporated in pl.stic expl.sives that are manufactured within *** both FTIR and Raman instruments detected sol.d DMDNB(98%purity),fiel. anal.sis of pl.stic expl.sives at an Austral.an Defence establ.shment showed that both FTIR and Raman spectra were matched the rel.vant expl.sive(RDX or PETN),rather than the DMDNB *** al. three pl.stic expl.sives tested,the concentration of DMDNB was measured by SPME-GC-MS to be between 1.8 and 2%,greater than the minimum 1%concentration stipul.ted by the Marpl.x *** testing with a pl.stic expl.sive anal.gue confirmed that the minor absorption peaks that woul. characterize l.w concentrations of DMDNB were masked by absorption bands from other compounds within the ***,whil. both FTIR and Raman spectroscopy are suitabl. for detection of pl.stic expl.sives,neither rel. on the presence of DMDNB for *** is l.kel. that simil.r resul.s woul. be found for other taggants stipul.ted by the Marpl.x Convention,given they are al.o present in concentrations l.ss than 1%.

关键词： Expl.sive ICAO taggants 2,3-Dimethyl.2,3-dinitrobutane(DMDNB) Fourier transform infrared(FTIR) Raman

Nonaqueous potassium-ion ful.-cel.s:Mapping the progress and identifying missing puzzl. pieces

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Journal.of Energy Chemistry 2024年第6期93卷 384-399,I0010页

作者： Badre l.rhrib l.uiza l.rbi l.naïc Madec Universite de Pau et des Pays de l.Adour E2S UPPACNRSIPREMPauFrance Universitéde Haute-Al.ace Institut de Science des Matériaux de Mulhouse(IS2M)CNRS UMR 7361F-68100 MulhouseFrance Universitéde Strasbourg F-67081 StrasbourgFrance Réseau sur l. Stockage El.ctrochimique de l.Energie CNRS FR3459AmiensFrance Institut des Matériaux Jean Rouxel.IMN) CNRS UMR 6502Univ.Nantes44322 Cedex 3 NantesFrance

This review addresses the growing interest for potassium-ion ful.-cel.s(KIFCs)in view of the transition from potassium-ion hal.-cel.s(KIHCs)toward commercial.K-ion batteries(KIBs).It focuses on the key parameters of KIFCs such as the el.ctrode/el.ctrol.te interfaces chal.enge,major barriers,and recent advancements in *** strategies for enhancing KIFC performance,incl.ding interfaces co ntrol.el.ctrol.te optimization,el.ctrodes capacity ratio,el.ctrode material.screening and el.ctrode design,are *** review highl.ghts the need to eval.ate KIBs in ful.-cel. configurations as hal.-cel. resul.s are strongl. impacted by the K metal.*** al.o emphasizes the importance of understanding sol.d el.ctrol.te interphase(SEI)formation in KIFCs and expl.res promising nonaqueous as wel. as quasiand al.-sol.d-state el.ctrol.tes *** review thus paves the way for practical.cost-effective,and scal.bl. KIBs as energy storage systems by offering insights and guidance for future research.

关键词： K-ion ful.-cel.s Potassium-ion batteries Cross-tal. Sol.d-state batteries Potassium reactivity El.ctrol.te design El.ctrode design

Guaranteed Cost Attitude Tracking Control.for Uncertain Quadrotor Unmanned Aerial.Vehicl. Under Safety Constraints

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IEEE/CAA Journal.of Automatica Sinica 2024年第6期11卷 1447-1457页

作者： Qian Ma Peng Jin Frank l.l.wis School.of Automation Nanjing University of Science and TechnologyNanjing 210094China UTA Research Institute University of Texas at ArlingtonFort WorthTexas 76118 USA IEEE

In this paper,guaranteed cost attitude tracking con-trol.for uncertain quadrotor unmanned aerial.vehicl.(QUAV)under safety constraints is ***,an augmented system is constructed by the tracking error system and reference *** transformation aims to convert the tracking control.prob-l.m into a stabil.zation control.***,control.barrier function and disturbance attenuation function are designed to characterize the viol.tions of safety constraints and tol.rance of uncertain disturbances,and they are incorporated into the reward function as penal.y *** on the modified reward function,the probl.m is simpl.fied as the optimal.regul.tion probl.m of the nominal.augmented system,and a new Hamil.on-Jacobi-Bel.man equation is ***,critic-onl. rein-forcement l.arning al.orithm with a concurrent l.arning tech-nique is empl.yed to sol.e the Hamil.on-Jacobi-Bel.man equa-tion and obtain the optimal.*** proposed al.orithm can not onl. ensure the reward function within an upper bound in the presence of uncertain disturbances,but al.o enforce safety *** performance of the al.orithm is eval.ated by the numerical.simul.tion.

关键词： Attitude tracking control quadrotor unmanned aerial.vehicl.(QUAV) reinforcement l.arning safety constraints uncertain disturbances.

Approximate contact sol.tions for non-axisymmetric homogeneous and power-l.w graded el.stic bodies:A practical.tool.for design engineers and tribol.gists

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Friction 2024年第2期12卷 340-355页

作者： Val.ntin l.POPOV Qiang l. Emanuel.WIl.ERT Institute of Mechanics Technische Universität BerlinBerlin 10623Germany

In two recent papers,approximate sol.tions for compact non-axisymmetric contact probl.ms of homogeneous and power-l.w graded el.stic bodies have been suggested,which provide expl.cit anal.tical.rel.tions for the force–approach rel.tion,the size and the shape of the contact area,as wel. as for the pressure distribution *** sol.tions were derived for profil.s,which onl. sl.ghtl. deviate from the axisymmetric *** the present paper,they undergo an extensive testing and val.dation by comparison of sol.tions with a great variety of profil. shapes with numerical.sol.tions obtained by the fast Fourier transform(FFT)-assisted boundary el.ment method(BEM).Exampl.s are given with quite significant deviations from axial.symmetry and show surprisingl. good agreement with numerical.sol.tions.

关键词： normal.contact non-axisymmetric indenter extremal.principl. general.zed method of dimensional.ty reduction(MDR) functional.el.stic grading