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基于碳涂层硫化锂阴极和电沉积硅基阳极的锂离子硫电池

外文数据库

93 用于无人机控制的头盔式显示器

An experiment was performed to assess the effect of using a Helmet Mounted Display (HMD) versus a conventional computer monitor and joystick to perform an Unmanned Aerial Vehicle (UAV) sensor operator target search task. Eight subjects were evaluated on objective performance measures including their target detection accuracy and responses, in addition to subjective measures including workload, fatigue, situational awareness, and simulator sickness in both experimental conditions. Subjects were flown through a virtual world and asked to identify objects as targets, non-targets, or distractors. Results for objective measures indicated no difference in the operators' ability to accurately classify targets and non-targets. The subjects' ability to place the cursor on a target of interset (targeting accuracy), was, however, significantly better in the computer monitor condition than the HMD. The distance at which subjects could classify an object's identity was also significantly better in the computer monitor condition. Subjective measures showed no overall differences for sel-reported fatigue, workload, and situational awareness. A significant disadvantage, however, was found for the HMD with respect to self-reported nausea, disorientation, and oculomotor strain. Results are discussed in terms of their implications for the incorporation of HMDs into UAV ground control station operations.""

外文数据库

基于图形切割的铅酸蓄电池自动分组系统

Theinconsistentparametersofdifferentlead-acidbatteriesinthesamebatterypackwillresultinthereductionofbatterypackcapacityandlife.Itisdifficulttofundamentallysolvetheinconsistentparametersproblemoflead-acidbatteries.Batterygroupingisasimpleandeffectiveapproachforsolvingtheperformanceinconsistencyproblembypackingbatterieswithclosecharacteristicparameters.Thetraditionalmanualgroupingmethodislaborintensiveandpronetoerrorsinmeasurementthatwillresultinwronggrouping.Inthisarticle,anovellead-acidbatteryautomaticgroupingsystemisdevelopedbasedongraphcuts.ThissystemconsistsofaPCserverend,awirelessrouter,andseveralportablegroupingdevices.Basedonembeddedreal-timeoperating,theproposedsystemrealizesbatteryparameterscharacterization,datauploading,andautomaticgroupingprocesses.Usingthisbatteryautomaticgroupingsystem,batterieswithclosechargeanddischargecharacteristicswillbegroupedintothesamebatterypack.Experimentalresultsdemonstratethattheproposedapproachcanprovidesuperiorperformanceovertraditionalmanualmethods.

外文数据库

使用全驱动无人机对排气管和烟囱进行自主物理检查

Multirotor UAVs are being widely employed for periodic inspections of large-scale industrial facilities to protect workers from hazardous conditions such as precarious heights and toxic chemicals. The government apparatus that ushered in the era of nuclear weapons and energy combines and compounds those hazards into enormous buildings and very high-consequence materials, many now reaching end-of-life. The decontamination and decommissioning of such structures sometimes requires inspection for low-levels of high- and low-energy radioactive materials and other toxic components. This often requires physical interaction for sampling or cleaning operations. However, manual control of physical interaction with UAVs requires experienced operators, induces fatigue, and the radio communication is often impeded by thick, reinforced walls that shield the materials. In this paper, an autonomous physical interaction control strategy to interact with the inside walls of exhaust shafts using fully-actuated UAV is proposed. In this method, the physical interaction is achieved by approaching normal to the surface, which is a precursor to establish a steady contact using hybrid physical interaction control. Estimating the local surface normal using the indoor positioning systems is limited by the low illumination and geometrical symmetry. Therefore, we estimate the local surface normal using the on-board 2D lidar and autonomously control the yaw orientation, along with planar position, in the approach phase. For mechanical simplicity, a rigid arm is attached to the fully-actuated UAV to perform contact-intensive tasks on the inside walls. Experiments were carried in laboratory and mock-up shaft of Dept. of Energy, to show the effectiveness in performing a contact-intensive task inside shafts.

外文数据库

生成良好且混乱的理想

We show that if the real line is the disjoint union of kappa meager sets such that every meager set is contained in a countable union of them, then kappa = omega_1. This answers a question addressed by J. Cichon. We also prove two theorems saying roughly that any attempt to produce the isomorphism type of the meager ideal in the Cohen real and the random real extensions must fail. All our results hold for "meager" replaced by "null", as well.

外文数据库

无人机侦察任务规划的混合优化框架

Applying unmanned aerial vehicles (UAVs) in military reconnaissance missions arises in recent years. It refers to using finite UAVs to reconnoiter some enemy targets with limited battery power, aiming at collecting valuable information as much as possible. While existing methods like heuristics and intelligent optimization methods have been widely applied, their performance on large-scale reconnaissance mission planning problems (RMPPs) is still unsatisfactory. This study proposes a hybrid optimization framework, namely, EA-DRL, to improve the optimization effect based on a problem decomposition strategy. In detail, the RMPP is decomposed into a target selection subproblem and a path planning subproblem. An evolutionary algorithm and a deep reinforcement learning method are proposed to solve them, respectively. Updating solutions to these two subproblems iteratively eventually completes the optimization of the given RMPP. Experimental results on different types of RMPP instances show great effectiveness and strong generalization ability of the proposed framework EA-DRL.

外文数据库

航测应用无人机自动驾驶系统开发

The Autopilot of Unmanned Aerial Vehicle (UAV) is a system with the capability of controlling roll, pitch, and yaw of UAV. It also capable to maintain the altitude of UAV automatically. Moreover, it assists UAV travel according to the waypoints and take-off/landing automatically. The features of Autopilot become important to support UAV tasks such as aerial mapping activities, territorial monitoring, and tourism documentation. The paper presents development of GPS-based UAV autopilot system that has several flying modes: (1) stabilize (user manually controls the movement of the aircraft using remote controller, the balance of the aircraft is automatically maintained by the autopilot), (2) automatic (the aircraft automatically flies along the waypoint), (3) take-off/landing (the plane lands and takeoff automatically). The proposed system is developed using Arduino Mega 2560 as the main controller to acquire sensor data, control the roll, pitch, and yaw of the plane, calculate the heading of the plane, and obtain the signal control to the servo motors. The sensors consist of an Inertial Measurement Unit (IMU) of MPU 6050 type, ultrasonic, barometer sensor of BMP 180, magnetometer, and GPS. The system uses Proportional Integral Derivative (PID) controller to maintain the position of the plane (roll, pitch, and yaw) and the altitude. Landing mode uses ultrasonic sensors to measure the altitude of the aircraft when the altitude is less than 3 meters. The proposed system has been successfully implemented and tested. The maximum error during waypoint mode is 50 meters.

外文数据库

电池驱动的火车为更清洁的世界提供了具有成本效益的乘车体验

Abatterysystemcouldpoweratrainforhundredsofkilometresbeforeneedingachargeofrenewableenergy.

外文数据库

基于大气压辉光放电激发源的电池式水性砷原子发射分析仪

Inthispaper,asensitiveatomicemissionspectrometer(AES)basedonanewlowpowerandlowargonconsumption(<8W,100mLmin–1)miniaturedirectcurrent(dc)atmosphericpressureglowdischarge(APGD)plasma(3mm×5mm)excitationsourcewasdevelopedforthedeterminationofarsenicinwatersamples.Inthismethod,arsenicinwaterwasreducedtoAsH3byhydridegeneration(HG),whichwasthentransportedtotheAPGDsourceforexcitationanddetectedbyacompactCCD(charge-coupleddevice)microspectrometer.DifferentparametersaffectingtheAPGDandthehydridegenerationreactionswereinvestigated.ThedetectionlimitforarsenicwiththeproposedAPGD-AESwas0.25μgL–1,andthecalibrationcurveswerefoundtobelinearupto3ordersofmagnitude.Theproposedmethodwassuccessfullyappliedtothedeterminationofcertifiedreferencematerial(GBW08605),tapwater,pondwater,groundwater,andhotspringsamples.MeasurementsfromtheAPGDanalyzershowedgoodagreementwiththecertifiedvalue/valuesobtainedwithwell-establishedhydridegenerationatomicfluorescencespectrometry(HG-AFS).Theseresultssuggestthatthedevelopedrobust,cost-effective,andfastanalyzercanbeusedforfieldbasedarsenicdeterminationandmayprovideanimportanttoolforarseniccontaminationandremediationprograms.

外文数据库

基于模糊控制器的耦合电感SEPIC变换器优化电池充电过程

Populationofhumanisgrowthupbutfossilenergyasmainfuelforgenerateelectricitysourcesbecomelessandless,soit'sneededrenewableenergysuchassolarenergyissuitableinIndonesia'sclimate.Solarenergyasasourceofelectricalenergycanbedoneusingphotovoltaic.Photovoltaiccanbeuseddirectlyorindirectly.Resultenergyfromindirectlyphotovoltaicisstoredfirstinthebattery.Ontheotherhand,outputvoltageofphotovoltaicisnotstable,ifusedforchargingabattery,itwillnotreachthesetpointcharging.TostabilizetheoutputvoltageofaphotovoltaiccanuseconvertersuchasSEPICConverterwithCoupledInductor.SimulationtheSEPICConverterwithcoupledinductorasaBatteryChargerusingFuzzyLogicControlcanstabilizetheoutputvoltagesothatthebatterychargingrunswell.FuzzylogiccontrolisusedtocontrolthegenerationofPWMtoproduceaconstantoutputvoltage.

外文数据库

用于无人机通信的 5G 地面网络部署性能

With the recent decrease in their size and cost, unmanned aerial vehicles (UAVs) have become more accessible for general-purpose applications. A natural way of providing network access to UAVs is to use terrestrial fifth generation (5G) deployments. In this paper, we assess 5G air-to-ground (A2G) links of low-height UAVs in suburban scenarios with system-level simulations. In order to obtain realistic results, we utilized a propagation channel model extracted from actual A2G measurements. We characterized the performance of the communication system by means of throughput results. We also showed the importance of the feedback delay optimization when the UAV flight speed is high, not only for the achievable throughput, but also for the end-to-end transmission delay, which may be crucial in critical communications (e.g., safety-related ones).

外文数据库

用于实际应用的电动汽车电池组的热分析和优化

Batterypacksareextensivelyusedinelectricalvehicles(EV)toavoidenvironmentalpollution.Thesafety,agingandlifeofbatterypackaresignificantlyrelatedtoitsthermalbehavior.ThisworkconcernswiththermalanalysisandoptimizationofanEVbatterypackforrealengineeringapplications.TheBernardi'sheatgenerationmodelwiththeconsiderationofreversibleheatisusedandvalidatedbytestsandnumericalsimulationonbatterycells.ThenthevalidatedcellmodelisappliedtoanEVbatterypackwithcoolingsystemunderneathforthestudyofthermalbehaviorattwoextremeoperationconditions,andnumericalresultsareingoodagreementwiththetestresults.Severalkeyfactorsimportanttothethermalbehaviorofbatterypacksarestudiedbyperformingsensitivityanalysisatthesetwooperationconditions,anditisfoundthattheinlettemperatureandtheinletflowarethetwomostsignificantfactors.ForbetterthermalperformanceoftheEVbatterypack,optimizationanalysisattwoextremeoperationconditionsisconductedtodeterminetheoptimalparametersfortheinlettemperatureandtheinletflow,andthisoptimizationprocessprovidesameanstofindoutthebestinputparametersforrealengineeringproblems."

外文数据库

一种新型层状水钠锰矿型钼酸钠作为双离子电极用于高容量电池

Abirnessite-typeNa1/3MoO2?H2Owithalargeinterlayerdistancehasbeensynthesizedbysolid-statereactionandwatertreatmentforthefirsttime.TheobtainedNa1/3MoO2?H2Oisphase-pureandwell-crystallizedasdeterminedbyX-raystructurerefinementandpresentsatypicalplate-likemicrostructure.Surprisingly,theNa1/3MoO2?H2OcanbeusedasbothanodeandcathodeelectrodesforLi-ionbatteries(LIBs),whichshowslongcyclelife((anode,500cycles~650mAhg?1),andhighcapacityof300mAhg?1(cathode).ThishighperformanceisascribedtothePF6?intercalationmechanismofNa1/3MoO2?H2Obasedonthedensityfunctionaltheory(DFT)calculations.ThisworkoffersanefficientwayforthedesignofelectrodematerialsandshedslightontheapplicationoftheNa1/3MoO2?H2Oforhighcapacitydual-ionbatteries(DIBs)."

外文数据库

电池汽车燃料电池增程器的多模电源处理接口

Uninhabitedelectricvehicletypicallyutilizebatteriesasanexclusivepowersource.Inordertoremedythelimitedenergydensityandthusoperationtimeofthebattery-poweredunmannedvehicles,fuelbasedrangeextendersareoftenutilized.Theoperationstrategyfortherangeextenderistomaximizethemissionendurancethereforeitshouldoperateatminimumspecificfuelconsumptionpoint.Furthermore,thesourceandloadvoltagelevelmaydiffer,hencenon-invertingBuck-Boostconverter(NBC)isconjointthemwhilekeepingthedesireoperationpoint.Thispaperproposesafuelcell(FC)basedrangeextender,interfacedtothemainpowerbusbycascadeoutputpowerregulationstrategyforNBC.TheNBCisbasedonuniquemodulatorthatproducesswitchingsequenceforbothconverterlegs.Themodulatorreceivesinglecontrolinputfromthedualloopregulator,innerinductorcurrentloopandouteroutputpowerloop,whichiscommonforenergymanagementstrategiesofhybridenergysources.SystemdesigncommenceswithregulatordesignbasedonsmallsignalanalysisofNBC,andthenitisshownthatthesuggestedcontrolarchitectureallowstightoutputpowercontrolthroughouttheentireoperatingrangedespitevariousplants.Finallyacasestudyispresented,inwhichtheconverteroperatesaspowerprocessinginterfaceofafuelcell,operatingasrangeextenderinanall-electricalaircraft.Therevealedfindingsarewell-supportedbysimulationandexperimentalresults.

外文数据库

锂离子电池行业会效仿太阳能光伏吗？

外文数据库

钠离子电池用原子层沉积氧化物纳米胶

外文数据库

监测马尔可夫源的版本创新时代和错误版本时代

In this paper, we propose two new performance metrics, coined the Version Innovation Age (VIA) and the Age of Incorrect Version (AoIV) for real-time monitoring of a two-state Markov process over an unreliable channel. We analyze their performance under the change-aware, semantics-aware, and randomized stationary sampling and transmission policies. We derive closed-form expressions for the distribution and the average of VIA, AoIV, and AoII for these policies. We then formulate and solve an optimization problem to minimize the average VIA, subject to constraints on the time-averaged sampling cost and time-averaged reconstruction error. Finally, we compare the performance of various sampling and transmission policies and identify the conditions under which each policy outperforms the others in optimizing the proposed metrics.

外文数据库

基于CLF的饱和约束无人机运动模型跟踪控制

This paper considers the trajectory tracking problem for unmanned air vehicles (UAVs). We assume that the UAV is equipped with an autopilot which reduces the twelve degree-of-freedom (DOF) model to a six DOF model with altitude, heading, and velocity command inputs. In this paper we restrict our attention to planar motion. One of the novel features of our approach is that we explicitly account for heading and velocity input constraints. For a fixed wing UAV, the velocity is constrained to lie between two positive constants, and therefore presents particular challenges for the control design. We propose a control Lyapunov function (CLF) approach. We first introduce a CLF for the input constrained case, and then construct the set of all constrained inputs that render the CLF negative. The control input is then selected from this ""feasible"" set. The proposed approach is then applied to a simulation scenario, where a UAV is assigned to transition through several targets in the presence of multiple dynamic threats.

外文数据库

一种基于循环一致性退化趋势的可转移锂离子电池剩余使用寿命预测方法

PredictingRemainingUsefulLife(RUL)oflithium-ionbatteriesplaysanimportantroleinbatteryhealthmanagement.TheexistingmethodshavesomelimitationsinbatteryRULprediction,includingtheproblemoferroraccumulationandtheinapplicabilityofRULmodelsunderdifferentworkingconditions.Foronebattery,theexistingpredictionmethodshavetheproblemoferroraccumulation;forbatteriesunderdifferentworkingconditions,thecorrespondinglifetimedistributionsarediscrete,somodelscannotbegeneralized.Toaddressaboveproblems,AtransferableRULpredictionmethodforlithium-ionbatteriesisproposed.Firstly,anEncodingNetthatcanextractglobaldegradationtendencyinformationisconstructedtomapthebatterydegradationdataintotherepresentationsubspace.Cycle-consistencylearningisusedtotraintheEncodingNetsothatpointswiththesamedegradationlevelbetweendifferentbatteriesarealignedwitheachother.Basedonalignedfeatures,anewRULpredictionmethod,consistingofoptimaldecisionofalignmentratioandintegratedpredictionusingBayesianmodelaveraging(BMA),isestablished.TheexperimentalresultsshowthattheproposedmethodcanachievehighpredictionaccuracyandalsoprovideanewperspectiveforRULprediction.

外文数据库

一种新的浆料概念，用于制备具有有益性能的锂离子电池电极

•WepresentanewslurryconceptbasedoncapillarysuspensionsforLi-ionelectrodes.•Theslurryviscosityinthelowshearregionistunableinawiderangewithoutfurtheradditives.•Theslurryviscosityinthehighshearregionremainsunchangedwhichisdesirableduringcoating.•Storagestabilityandshapeaccuracyduringcoatingareimprovedsignificantly.•Goodmechanicalandelectrochemicalpropertiesofthenovelelectrodesareshown.

外文数据库

智能铁路 IRS 辅助无人机网络轨迹优化和相移设计

The recent trend towards the smart transportation system has spurred the development of the smart railway. However, enabling trains with seamless wireless connectivity using the roadside units (RSUs) is extremely challenging, mostly due to the lack of line of sight link. To address this issue, we propose a novel framework that uses intelligent reflecting surfaces (IRS)-enabled unmanned aerial vehicle (UAV) to provide line of sight communication to the smart railway system. First, we formulate the optimization problem where the objective is to maximize the minimum achievable rate of trains by jointly optimizing the trajectory of UAV and the phase-shift of IRS. Due to the non-convex nature of the formulated problem, it is decomposed into two subproblems: IRS phase-shift problem and UAV trajectory optimization problem. Next, a Binary Integer Linear Programming (BILP) and a Soft Actor-Critic (SAC) are constructed in order to solve our decomposed problems. Finally, comprehensive numerical results are provided in order to show the effectiveness of our proposed framework.

外文数据库

电池应用粘合剂

外文数据库

使用美国国立卫生研究院工具箱电池评估弥漫性脑胶质瘤患者的认知、情绪和运动领域

Patientswithbraintumorsareknowntohavedeficitsincognitive,motor,andemotionaldomains.Comprehensiveevaluationofthepatientwithbraintumorincludestakingintoaccountallthesedomainsatbaselineandthroughouttreatment.Standardneuropsychologicalassessmentmethods,however,arelengthy,expensive,andoftenarevariable.Theauthorsappraisedthefeasibilityofusingabrief,inexpensive,comprehensive,andstandardizedneuropsychologicalbattery,theNationalInstitutesofHealth(NIH)Toolbox,toassessthesedomainsinpatientswithdiffuseglioma.MethodsEighteenpatientswererecruitedandcompletedtheNIHToolboxCognitiveBattery,2motortests(GripStrengthandGroovedPegboard),andtheNIHToolboxEmotionalBattery.FullycorrectedTscoresarereported,aswellascompositescoresoffluidandcrystallizedcognition.Follow-upcognitive(n=13)andmotorassessment(n=12)wereperformedat1monthaftersurgery.ResultsThetotaltimetocompletethebatterywasapproximately60minutes.Atotalof78%ofpatientsdemonstratedsignificantimpairmentononeormorecognitivetest,whereas37%hadimpairedfluidcognition.Crystallizedandoverallcompositecognitivescoreswererelativelyintact,with16%ofpatientsshowingsignificantimpairment.Atotalof22%ofpatientshadimpairedstrengthinthelefthand,and22%hadimpaireddexterityinbothhands.Inaddition,50%ofpatientsshowedimpairmentinoneormoreemotionaldomain.At1monthaftersurgery,asignificantdecreaseincrystallizedcognitionwasobserved.ConclusionsTheNIHToolboxrepresentsafeasiblealternativetocurrentneuropsychologicalbatteriesintheassessmentofneurosurgicalpatients.Itcanbeadministeredquickly,inexpensively,andwillgivetheneurosurgicalcommunityacommoncurrencywhenreportingneuropsychologicalresults.

外文数据库

独立的混合光伏、燃料电池和电池系统：以巴西托坎廷斯为例

Abstract:Thispaperaimedtoevaluatetheuseofaphotovoltaic-fuelcell-batterysystemtosupplyelectricpowerinanisolatedcommunityintheAmazonregion.Thestudyfocusedontechnicalandcostissuesofapilot-projectsetupinanenvironmentalprotectionarea,locatedinthestateofTocantins,Brazil.AcomparativeanalysisofthecostsofthehybridsystemafteroptimizationwasmadewiththeaidoftheHOMER?(HybridOptimizationModelforElectricRenewables)program.Theanalysisshowsthattheoptimalsystem'sinitialcost,netpresentcost,andelectricitycostwiththehydrogenstoragesystemisUS$87,138;US$102,323;andUS$1.351/kWh,respectively.Componentsarecostly(fuelcellandelectrolyzer),withthephotovoltaicmodulesandtheelectrolyzerpresentingthemaincostofsystem.Basedontheresults,thestudyconfirmedthatthebestoptionforstoringenergyfromphotovoltaicsystemsisstilltheuseofbatteries.Intheshortterm,implementationofhybridphotovoltaic-fuelcell-batterysystemintheregionremainsprohibitiveduetothehighcostofitscomponents.

外文数据库

扩大无人机系统

外文数据库

提出使用 YIN 基频估计器和音调声音进行水下推进器故障分类的多级极限机器学习框架

Unmanned underwater vehicles (UUV) have been used for many ocean related applications such as scientific exploration, surveillance, marine development, marine engineering and military purposes. However, the risk of damage or loss of property for unmanned underwater vehicle is often a major concern and thruster had been found to be the most common source of faults. Based on the audio recordings using a hydrophone on different thruster's state such as broken propeller fin and propeller entangled with seaweed, fundamental frequency (by YIN fundamental frequency estimator), pitch and root-mean squared (RMS) are extracted for multi-level extreme learning machine (ELM) to perform classification of thruster's faults. However, multi-level machine learning is often built on binary classification for each level with same parameters for each level may not be the most optimal to build a multi-level machine learning. In this paper, a new framework for multi-level ELM is developed using chi-square value that can obtain the optimal parameters from the list of inputs at each level using least number of parameters. Based on this framework, ELM can achieve a 100% accuracy and a comparison to different machine learning algorithms such as Decision Tree and Support Vector Machine using the same parameters show similar accuracy.

外文数据库

先进的中温氯化钠铜电池

•TheconductivityoftheNaClbufferedEMIC:AlCl3meltis0.247Scm−1at150°C.•TheNa/CuCl2cellusingNaClbufferedEMIC:AlCl3meltcanbeoperatedat150°C.•TheNa/CuCl2cellexhibitsanenergydensityashighas750mWhg−1.•ThefirstcoulombicefficiencyoftheNa/CuCl2cellisashighas99.8%.

外文数据库

LiCoO2锂离子电池阴极的模拟退火重建与表征

Wereconstructthethree-dimensionalmicrostructureofacathodefromacommercialLiCoO2Lithium-ionbatterywithanadaptedsimulatedannealingapproach.TherealsizedistributioncurveofLiCoO2particlesisappliedtoregulatethereconstructionprocess.Bydiscretizinga40μm×40μm×40μmcathodevolumewith8000000numericalcubes,thecathodeinvolvingthreeindividualphases:(1)LiCoO2asactivematerial,(2)poresorelectrolyte,and(3)additives(polyvinylidenefluoride+carbonblack)isreconstructed.Characterizationofthereconstructedcathodegivesimportantstructuralandtransportpropertiesincludingvolume-specificsurfaceareabetweenphases,tortuosityandgeometricalconnectivityofindividualphase.

外文数据库

多无人机网络环境感知的无人机协同部署和任务分配

This paper investigates the collaborative unmanned aerial vehicle (UAV) sensing in multi-UAV networks. By equipping sensors, communication units and computation units on UAVs, they can sense the environment by executing surveillance tasks and computation tasks. UAVs execute surveillance tasks by mon-itoring the environment and computation tasks by processing the sensing information offloaded from ground terminal nodes. We formulate the collaborative multi-DAV sensing problem as a joint optimization problem of UAV deployment and task allocation. The goal is to maximize the sensing utility, which is defined as the weighted sum of utility for executing surveillance and computation tasks. Note that UAV deployment and task allocation are highly coupled, we divide the joint optimization problem into two sub-problems and then propose an iterative mechanism by optimizing two sub-problems iteratively. UAV deployment optimization problem is non-convex, and thus we utilize a differential evolution (DE) algorithm to solve it with high efficiency and simple implementation. Task allocation optimization problem is proven to be NP-hard, and thus we propose a particle swarm optimization method with greedy-based reconstruction (PSOGR) to solve this complex combinatorial optimization problem efficiently. Simulation results demonstrate the benefits of our proposed method compared with existing algorithms for different system parameters.

外文数据库

活动星系核中心磁层致密云大小的物理约束

The range of microphysical and global dynamical timescales in the central regions of Active Galactic Nuclei (AGN) is sufficiently wide to permit the existence of multiphase structure. In particular, very dense, cool clouds can coexist with a hot, magnetically-dominated medium and can thereby efficiently reprocess the continuum radiation generated in this primary source region. The strong dynamical forces in this central magnetosphere can give rise to extremely small clouds. Microphysical processes then determine whether such clouds can indeed survive, in spite of their extremely contrasting properties relative to the surrounding environment, for long enough to produce potentially observable thermal reprocessing signatures. We examine specific physical constraints on the thicknesses of such reprocessing clouds. Our results are plotted to show the range of conditions that is representative of the central regions of AGN. We find a parameter subspace in the extreme high density regime for which the effects of microphysical diffusion processes can be overcome and for which cool gas can maintain pressure equilibrium with the ambient magnetosphere.

外文数据库

国防部签署猎户座无人机供货合同

The Russian Defense Ministry and the Kronstadt company have signed the first series contract for the supply of Orion unmanned aerial vehicles (UAVs), said Nikolai Dolzhenkov, general designer of the "Kronstadt". "The contract with the Russian Defense Ministry for series deliveries of the Orion UAV has been signed - I cannot disclose the details of the agreement," he said. Mr. Dolzhenkov noted that, following the results of the experimental military operation of the Orion, the military department asked to modify this UAV - to add "a number of additional capabilities....

外文数据库

用根轨迹法分析和综合无人机控制系统 - IEEE 会议出版物

The basic principles and capabilities of the root locus method in the study of control systems for unmanned aerial vehicles are considered.

外文数据库

电沉积Co-Fe作为析氧反应电催化剂的组分效应

CobaltandFewereco-electrodepositedassinglecrystal,facetedparticlesontocarbonpapertoproduceCo/Fe-oxyhydroxideoxygenevolutionreaction(OER)catalystswithvariousCo/Feratios.ElectronmicroscopyandAugerelectronspectroscopywereusedtoinvestigatethemorphologyandcompositionoftheelectrodeposits.IroncontentinthedepositsincreasedwithincreasingFeconcentrationintheelectrolyteandFesegregatedtotheparticlesurfaces.ElectrochemicaltestsdemonstratedthatthedepositCo/FeratioinfluencesOERactivitybyalteringtheelectrochemicallyactivesurfacearea(ECSA)andchargetransferresistance.TheOERactivityincreasedwithincreasingFecontentupto?65?at%Fe,withaminimumoverpotentialof0.33?V?at10?mA?cm?2in1?MKOH.ThefabricatedOERcatalystswereassembledintoaZn-airbatteryfordischarge-chargecyclingtestsandshowedlowerchargepotentialscomparedwithbarecarbonpaper.

外文数据库

层状 Co 掺杂 MnO2 具有丰富的氧缺陷以促进水性锌离子存储

ZincManganeseoxide(Zn/MnO2)-basedaqueousbatteryisfavoredduetotheirhighspecificcapacity,securityandcostperformance.Nevertheless,theyusuallyproblemsofunstablecyclicstructureandslowdiffusionkinetics,restrictingtheirpracticalapplication.Here,wehavesuccessfullysynthesizedaCodopedMnO2cathodematerialwithabundantdefectsonacarbonclothsubstrate.Throughasimplehydrothermalmethod,theCoelementcanbelightlyintercalatedinthetwo-dimensional(2D)layeredα-MnO2nanowires,inhibitingthestructuraltransformationduringthecycleandimprovethestabilityofthematerial.Meanwhile,plasmatechnologyfacilitatestheformationofoxygenvacanciesintheelectrodematerial,whichnotonlyaccelerateelectrondiffusionbutalsoimprovetheconductivity.Therefore,Zn/Co-MnO2batterycanreachaspecificcapacityof511mAhg?1at0.5Ag?1andtheretentionrateaccomplish98%athighcurrentdensity.Thisresearchputsforwardastrategyofelementdopingandphysicalpreparationofoxygenvacancies,whichprovidesthepossibilitytodevelopreversibleZn/MnO2-basedaqueousbatterycathodematerialswithhigh-performance.

外文数据库

汽车锂离子电池生命周期中材料生产、装配和寿命终止阶段的材料和能量流

外文数据库

复合非线性扩展态观测器及其在无人地面车辆中的应用

In this paper, a disturbance-observer-based control strategy is proposed for longitudinal control and lateral control of unmanned ground vehicles. A composite nonlinear extended state observer is put forward to estimate the total disturbance. A longitudinal dead-zone model is developed with actual constraints and rapidity requirements for unmanned ground vehicles. The disturbance-observer-based feedback controller is presented to improve the robustness of the closed-loop system by incorporating the composite nonlinear extended state observer. Numerical and experimental results are given to verify the effectiveness of the proposed control strategy.

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基于部分增量容量和支持向量回归的锂离子电池健康状态估计新方法

外文数据库

黎曼泛函和算术群的变分问题

In this paper we introduce a new approach to variational problems on the space Riem(M^n) of Riemannian structures (i.e. isometry classes of Riemannan metrics) on any fixed compact manifold M^n of dimension n >= 5. This approach often enables one to replace the considered variational problem on Riem(M^n) (or on some subset of Riem(M^n)) by the same problem but on spaces Riem(N^n) for every manifold N^n from a class of compact manifolds of the same dimension and with the same homology as M^n but with the following two useful properties: (1) If \nu is any Riemannian structure on any manifold N^n from this class such that Ric_(N^n,\nu) >= -(n-1), then the volume of (N^n,\nu) is greater than one; and (2) Manifolds from this class do not admit Riemannian metrics of non-negative scalar curvature. As a first application we prove a theorem which can be informally explained as follows: Let M be any compact connected smooth manifold of dimension greater than four, M et(M) be the space of isometry classes of compact metric spaces homeomorphic to M endowed with the Gromov-Hausdorff topology, Riem_1(M) in M et(M ) be the space of Riemannian structures on M such that the absolute values of sectional curvature do not exceed one, and R_1(M) denote the closure of Riem_1(M) in M et(M ). Then diameter regarded as a functional on R_1(M) has infinitely many "very deep" local minima.

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高面积容量锂离子电池超稳定阳极用氮掺杂焦糖护套双向混合氧化物纳米阵列的设计形成

Nanoarrayshavearousedgreatconcerninboostingthecyclicstabilityoflithium-ionbatteriesbecauseoftheirprominentsuperioritiesinshorteningdiffusionpathofLi+ions,andresolvingdisadvantagesofpooranchorabilityofactivematerials.Herein,bilateralnanoarraysself-supportingelectrodecomposedofCoca-Cola-basedN-dopedcaramelsheathedNiCo2O4/Co3O4/Al2O3in-situanchoredonNifoamsubstratewassynthesizedviamicrowave-assistedmethod.ThemorphologiesoftheinnerandoutersidesofNifoamsubstratearedifferent.Thein-situformationofbilateralnanoarraysnotonlycausesdissolutionofinterlayertoingeniouslyformNiCo2O4,butalsoreinforcesadhesion.Coca-Cola-baseduniqueN-dopedmicro-mesoporouscaramelisusedforthefirsttimetoboostelectrochemicalperformance.Specifically,thecarbon/binderfreebilateralnanoarrayselectrodecomposedofCoca-Cola-basedcaramelsheathedNiCo2O4/Co3O4/Al2O3possessahighreversiblecapacity(1.28?mA?h?cm?2at0.5?mA?cm?2for200cycles),exhibitultra-stableandhighratecyclicstability(0.27?mA?h?cm?2at4?mA?cm?2over2500cycles,and0.25?mA?h?cm?2atahighrateof6?mA?cm?2over1500cycles).Thisworkproposesarationalstrategytoenhanceelectrochemicalperformanceforhybridoxidesself-supportingelectrode."

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寻找“矮子”Seyfert Nuclei。III、宿主星系的光谱参数和性质

We have completed an optical spectroscopic survey of the nuclear regions (r < 200 pc) of a large sample of nearby galaxies. Although the main objectives of the survey are to search for low-luminosity active galactic nuclei and to quantify their luminosity function, the database can be used for a variety of other purposes. This paper presents measurements of the spectroscopic parameters for the 418 emission-line nuclei, along with a compilation of the global properties of all 486 galaxies in the survey. Stellar absorption generally poses a serious obstacle to obtaining accurate measurement of emission lines in nearby galactic nuclei. We describe a procedure for removing the starlight from the observed spectra in an efficient and objective manner. The main parameters of the emission lines (intensity ratios, fluxes, profile widths, equivalent widths) are measured and tabulated, as are several stellar absorption-line and continuum indices useful for studying the stellar population. Using standard nebular diagnostics, we determine the probable ionization mechanisms of the emission-line objects. The resulting spectral classifications provide extensive information on the demographics of emission-line nuclei in the local universe. This new catalog contains over 200 objects showing spectroscopic evidence for recent star formation and an equally large number of active galactic nuclei, including 46 which show broad H-alpha emission. These samples will serve as the basis of future studies of nuclear activity in nearby galaxies.

外文数据库

完全布尔代数上的序列拓扑

We investigate the sequential topology $\tau_s$ on a complete Boolean algebra $B$ determined by algebraically convergent sequences in $B$. We show the role of weak distributivity of $B$ in separation axioms for the sequential topology. The main result is that a necessary and sufficient condition for $B$ to carry a strictly positive Maharam submeasure is that $B$ is ccc and that the space $(B,\tau_s)$ is Hausdorff. We also characterize sequential cardinals.

外文数据库

串联和并联锂离子电池模块的电池性能和不一致性演变研究

Lithium-ionbatterycellsareusuallyconnectedinseriesorparalleltoformmodulestomeetpowerandenergyrequirementsforspecificapplications.Inconsistencyofthecells’performance,i.e.,capacityandinternalresistance,isinitiallyformedduringproduction.Thentheinconsistencyevolvesinthelifespan.Herein,theperformanceandinconsistencyevolutionoftheseriesandparallelmodulesforthedesignandmanagementguideareinvestigated.Aquantitativeanalysisoftheperformanceandinconsistencyismade.Theperformanceandinconsistencyevolutionareinvestigatedexperimentally.Basedonit,thetrendjudgmentoftheinconsistencyevolutionisderived.Itisfoundthatthecellperformanceinseriesmodulesisself-divergent,especiallyinthelaterstageoftheagingprocess.Andthedivergencebecomesmoreseverewithanunreasonableequalization,suchasthetraditionalcellvoltageequalization.Equalizationofthecellperformanceisneededtocutofftheviciouscircle.Fortheparallelmodule,self-convergenceoftheperformanceexists.Thebetter-performingcellsinthemodulewithstandalargercurrent,makingtheirperformancedecayfasterandfinallybecomingconsistentwiththecellswithworseinitialperformance.Meanwhile,theparallelmoduleperformancealsodecayssignificantly.Therefore,maintainingthecells’consistencyisstillnecessaryfortheparallelmodules.

外文数据库

分流电流对电池效率的影响研究？钒氧化还原液流电池的堆温

Invanadiumredoxflowbatteries(VFB),thepowerofthebatteryisdeterminedbythenumberofcellsinthestack.Serialandparallellayoutsarecommonlyadoptedinteractivelytosuitthedesignedpowerdemand.Thebipolarstackdesigninevitablyintroducesshuntcurrentsbypassingintothecommonmanifoldsinthestackandtherebyresultinginaparasiticlossofpowerandenergy.Duringstandby,shuntcurrentanditsassociatedinternaldischargereactionscangenerateheatandincreasestacktemperature,potentiallyleadingtothermalprecipitationinthepositivehalf-cell.Thisstudyaimstoinvestigatetheeffectofshuntcurrentonstackefficiencyandtemperaturevariationduringstandbyperiodsfora40-cell?stack.Dynamicmodelsbasedonmassbalance,energybalanceandelectricalcircuitaredevelopedforsimulationsandtheresultsprovideaninsightintostackperformancethatwillaidinoptimisingstackdesignandsuitablecoolingstrategiesfortheVFB.

外文数据库

生物质衍生的三维分级氮掺杂多孔碳锚定磷化钴铁纳米点作为LiO2电池的双功能电催化剂

Developinglithium-oxygenbatterieswithhighreversibilityandlongcyclabilityrequiresanelectrocatalystwithsuperiorcatalyticactivityandexcellentstabilitytoachieveanefficientcathode.Herein,athree-dimensionalhierarchicallyporouscarbonframeworkembeddedwithcobalt-iron-phosphidenanodotsnanocompositeisfabricatedviaalyophilization-pyrolysis-phosphorizationprocess.Thesyntheticcatalystdisplaysexcellentperformancestowardsboththeoxygenreductionreactionandtheoxygenevolutionreaction.Withouroptimalsample,thehalf-wavepotentialfortheoxygenreductionreactionisupto0.83?Vversusreversiblehydrogenelectrode,anditspotentialfortheoxygenevolutionreactionatacurrentdensityof10?mA?cm?2isaslowas1.53?Vin0.1?MKOHsolution.Thecatalystalsoexhibitsimprovedelectrochemicalperformancesinarechargeablelithium-oxygenbattery,includingahighspecificcapacity(11969?mAhg?1at100?mA?g?1)andalongcyclelife(141cyclesatacut-offcapacityof1000?mAhg?1).Alloftheseresultsmakeourcatalystapromisingcandidateforthedevelopmentofhighlyefficientelectrocatalystsfortherechargeablelithium-oxygenbatteries.

外文数据库

基于无人机的网络化机载计算的动态编码分布式卷积

A single unmanned aerial vehicle (UAV) has limited computing resources and battery capacity, making it difficult to handle computationally intensive tasks such as the convolution operations in many deep learning applications. UAV-based networked airborne computing (NAC) is a promising technique to address this challenge. It allows UAVs within a range to share resources among each other via UAV-to-UAV communication links and carry out computation-intensive tasks in a collaborative manner. This paper investigates the vector convolution problem over the NAC architecture. A novel dynamic coded convolution strategy with privacy awareness is developed to address the unique features of UAV-based NAC, including node heterogeneity, frequently changing network typologies, time-varying communication and computation resources. Simulation results show its high efficiency and resilience to uncertain stragglers.

外文数据库

带氰基的两性离子改善锂离子二次电池用寡醚电解质的充放电性能

Zwitterionswithacyanogrouponthesidechain(CZ)weresynthesized.AlthoughtheadditionofCZcausedaslightlynegativeeffectonviscosity,ionicconductivity,limitingcurrentdensity,andlithiumtransferencenumber,theoxidationlimitofPEGDME/lithiumbis(trifluoromethylsulfonyl)amide(LiTFSA)compositeswasimprovedtoover5 V.Forcharge/dischargetestingusingLi|electrolyte|LiCoO2cells,thecyclestabilityofPEGDME/LiTFSAwithCZinthevoltagerangeof3.0–4.6 VwasmuchhigherthanthatofPEGDME/LiTFSA.IncorporatingasmallmolefractionofCZintoPEGDME-basedelectrolytespreventedanincreaseintheinterfaceresistancebetweentheelectrolyteandcathodewithincreasingnumbersofthecycle.

外文数据库

基于改进样本熵的锂离子电池组串多故障诊断方法

Theconventionalfault-diagnosismethodsaredifficulttodetectthebatteryfaultsintheearlystageswithoutobviousbatteryabnormalitybecauselithium-ionbatteriesarecomplexnonlineartime-varyingsystemswithabsolutecellinconsistency.Therefore,thispaperproposesareal-timemulti-faultdiagnosismethodfortheearlybatteryfailurebasedonmodifiedSampleEntropy.BydetectingthemodifiedSampleEntropyofthecell-voltagesequencesinamovingwindow,theproposeddiagnosismethodcandiagnoseandpredictdifferentearlybatteryfaults,includingshort-circuitandopen-circuitfaults,andcanalsopredictthetimeofthefaultsoccurring.Theexperimentalresultsandthecomparisonwiththeconventionalmethodsverifythevalidityoftheproposedsolutionwithstrongrobustness,highreliabilityandlowcomputationalcost,andwithouttheneedofaprecisemodel.Insummary,theproposedmulti-faultdiagnosisapproachisfeasibleandpromisinginrealelectricvehicleapplications."

外文数据库

局域群的X射线晕及其对微波和软X射线背景的影响

Since recent X-ray observations have revealed that most clusters of galaxies are surrounded by an X-ray emitting gaseous halo, it is reasonable to expect that the Local Group of galaxies has its own X-ray halo. We show that such a halo, with temperature $\sim 1$keV and column density $\sim O(10^{21}) {\rm cm}^{-2}$, is a possible source for the excess low-energy component in the X-ray background. The halo should also generate temperature anisotropies in the microwave background via the Sunyaev-Zel'dovich effect. Assuming an isothermal spherical halo with the above temperature and density, the amplitude of the induced quadrupole turns out to be comparable to the COBE data without violating the upper limit on the $y$-parameter. The induced dipole is negligible compared to the peculiar velocity of the Local Group, and multipoles higher than quadrupole are generally much smaller than the observed ones. However non-sphericity and/or clumpiness of the halo will produce a stronger effect. Therefore the gaseous halo of the Local Group, if it exists, will affect the estimate of the primordial spectral index $n$ and the amplitude of the density fluctuations deduced from the {\sl COBE} data.

外文数据库

氯化铵辅助空气氯化从废铅酸电池火法渣中回收锡

Tin-containingslagfrompyrometallurgicalrecoveryprocessofspentlead-acidbatteryisavaluablesecondarySnresource.However,thelowcontentofSn(~4wt%)inthisslagwithcompleximpurities(Fe,Al,Pb,Zn,andCu,etc.)makesitchallengingforefficienttinseparation.Inthisstudy,alow-temperaturechlorinatingprocessisproposedfortinrecoveryfromthetin-containingslagbyusingammoniumchlorideasthechlorinatingreagent.Undertheoptimizedchlorinatingconditions,tinvolatilizationratiosofabove96%underbothairandvacuumatmospherescouldbeachieved.However,thediscrepancybetweenthetemperaturesoftinchlorinatingandimpuritymetalchlorinatingismoredramaticundertheairatmospherethanthatundervacuum,whichfacilitatestheseparationofimpurities.Meanwhile,thedecompositionrateofNH4Clinairismuchlowerthanthatundervacuumatmosphere,resultinginlessconsumptionofNH4Cl.Theobtainedchlorinatedcondensationproductinairissubjectedtoasubsequentwaterleaching-alkalismelting-leaching-crystallizationprocesstoeffectivelyseparateFeimpurityandobtainthefinalsodiumstannateproductwithatotaltinrecoveryratioof94%.Thisstudyprovidesapromisingstrategyfortherecoveryoftin,andsignificantenvironmentalbenefitcouldbegeneratedsimultaneouslywithsolidwasterecycling.

外文数据库

水系锌电池锰基材料的反应机理及优化策略

Aqueousrechargeablebatterieshavebeenconsideredaspromisingcandidatestoachievetherequirementsforthestationaryenergystoragesystem.Inrecentyears,numerousstudieshavefocusedonaqueousrechargeablezincbatteries(ARZBs)duetotheirmeritsoflow-cost,materialabundance,acceptableenergydensity,andenvironmentalfriendliness.Thefundamentaladvancesinenergystorageofbatteriesarelargelydependentontheelectrodematerials.FocusingontherecentadvancesofARZBs,inthisreview,thereactionmechanisms,electrochemicalperformances,andchallengesaboutMn-basedmaterialsforARZBsaresystematicallyintroduced.Meanwhile,theoptimizationstrategiesforhigh-performanceMn-basedmaterialswithdifferentnanostructures,morphologies,andcompositionsforARZBsarediscussedaswell.ThispapercombiningreviewsandperspectivesofMn-basedelectrodesmayshedlightonthedevelopmentofadvancedaqueouszincbatteries.

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