检索结果-南通市图书馆

Elliptical encirclement control capable of reinforcing performances for UAVs around a dynamic target

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 104-119页

作者： Fei Zhang Xingling shao Yi xia Wendong Zhang National Key Laboratory for Electronic Measurement Technology School of Instrument and ElectronicsNorth University of ChinaTaiyuan030051China

Most researches associated with target encircling control are focused on moving along a circular orbit under an ideal environment free from external ***,elliptical encirclement with a time-varying observation radius,may permit a more flexible and high-efficacy enclosing solution,whilst the non-orthogonal property between axial and tangential speed components,non-ignorable environmental perturbations,and strict assignment requirements empower elliptical encircling control to be more challenging,and the relevant investigations are still *** this line,an appointed-time elliptical encircling control rule capable of reinforcing circumnavigation performances is developed to enable Unmanned Aerial Vehicles(UAVs)to move along a specified elliptical path within a predetermined reaching *** remarkable merits of the designed strategy are that the relative distance controlling error can be guaranteed to evolve within specified regions with a designer-specified convergence ***,wind perturbations can be online counteracted based on an unknown system dynamics estimator(USDE)with only one regulating parameter and high computational *** tool demonstrates that all involved error variables are ultimately limited,and simulations are implemented to confirm the usability of the suggested control algorithm.

关键词： Elliptical encirclement Reinforced performances Wind perturbations UAVs

An M-VCUT level set-based data-driven model of microstructures and optimization of two-scale structures

在线全文

学校读者我要写书评

暂无评论

Frontiers of Mechanical Engineering 2024年第4期19卷 73-86页

作者： Minjie shao Tielin SHI Qi xia State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

The optimization of two-scale structures can adapt to the different needs of materials in various regions by reasonably arranging different microstructures at the macro scale,thereby considerably improving structural ***,a multiple variable cutting(M-VCUT)level set-based data-driven model of microstructures is presented,and a method based on this model is proposed for the optimal design of two-scale *** geometry of the microstructure is described using the M-VCUT level set method,and the effective mechanical properties of microstructures are computed by the homogenization ***,a database of microstructures containing their geometric and mechanical parameters is *** two sets of parameters are adopted as input and output datasets,and a mapping relationship between the two datasets is established to build the data-driven model of *** the optimization of two-scale structures,the data-driven model is used for macroscale finite element and sensitivity *** efficiency of the analysis and optimization of two-scale structures is improved because the computational costs of invoking such a data-driven model are much smaller than those of homogenization.

关键词： two-scale structure structural optimization M-VCUT level set homogenization radial basis function data-driven

Trotter–Kato Approximations of Impulsive Neutral SPDEs in Hilbert Spaces

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第5期40卷 1229-1243页

作者： Ming LIU xia ZHANG ling Fei DAI School of Mathematical Sciences Tiangong UniversityTianjin 300387P.R.China

This paper studies a class of impulsive neutral stochastic partial differential equations in real Hilbert *** main goal here is to consider the Trotter-Kato approximations of mild solutions of such equations in the pth-mean(p≥2).As an application,a classical limit theorem on the dependence of such equations on a parameter is *** novelty of this paper is that the combination of this approximating system and such equations has not been considered before.

关键词： Impulsive neutral stochastic partial diferential equation Trotter-Kato approximations classical limit theorem

Joint Optimization of Trajectory and Task Offloading for Cellular-Connected Multi-UAV Mobile Edge Computing

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第3期33卷 823-832页

作者： Jingming xia Yufeng LIU ling TAN School of Artificial Intelligence Nanjing University of Information Science and Technology Engineering Research Center of Digital Forensics Ministry of Education Nanjing University of Information Science and Technology

Since the computing capacity and battery energy of unmanned aerial vehicle(UAV) are constrained,UAV as aerial user is hard to handle the high computational complexity and time-sensitive *** paper investigates a cellular-connected multi-UAV network supported by mobile edge *** UAVs carrying tasks fly from a given initial position to a termination position within a specified *** handle the large number of tasks carried by UAVs,we propose a energy cost of all UAVs based problem to determine how many tasks should be offloaded to high-altitude balloons(HABs) for computing,where UAV-HAB association,the trajectory of UAV,and calculation task splitting are jointly ***,the formulated problem has nonconvex ***,an efficient iterative algorithm by applying successive convex approximation and the block coordinate descent methods is put ***,in each iteration,the UAV-HAB association,calculation task splitting,and UAV trajectory are alternately ***,for the nonconvex UAV trajectory optimization problem,an approximate convex optimization problem is *** numerical results indicate that the scheme of this paper proposed is guaranteed to converge and also significantly reduces the entire power consumption of all UAVs compared to the benchmark schemes.

关键词： Energy consumption Multi-access edge computing Costs Power demand Autonomous aerial vehicles Iterative algorithms Convex functions

Differences in insomnia-related self-reported outcomes among elderly hospitalized patients

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

World Journal of Psychiatry 2024年第5期14卷 686-694页

作者： xia Ding ling-xia Qi Dong-Yun Sun Department of Gangzha General Medical Center The Affiliated Hospital of Nantong UniversityNantong 226000Jiangsu ProvinceChina Department of Anesthesiology and Surgery The Affiliated Hospital of Nantong UniversityNantong 226000Jiangsu ProvinceChina Department of Ophthalmic Surgery Room The Affiliated Hospital of Nantong UniversityNantong 226000Jiangsu ProvinceChina

Insomnia is among the most common sleep disorders *** in older adults is a social and public health *** affects the physical and mental health of elderly hospitalized patients and can aggravate or induce physical *** subjective feelings and providing reasonable and standardized care for elderly hospitalized patients with insomnia are urgent *** To explore the differences in self-reported outcomes associated with insomnia among elderly hospitalized *** One hundred patients admitted to the geriatric unit of our hospital between June 2021 and December 2021 were included in this ***-reported symptoms were assessed using the Athens Insomnia Scale(AIS),Generalized Anxiety Disorder Scale-7(GAD-7),Geriatric Depression Scale-15(GDS-15),Memorial University of Newfoundland Scale of Happiness(MUNSH),Barthel Index Evaluation(BI),Morse Fall Scale(MFS),Mini-Mental State Examination,and the Short Form 36 Health Survey Questionnaire(SF-36).Correlation coefficients were used to analyze the correlation between sleep quality and self-reported *** of insomnia was analyzed using Logistic regression *** Nineteen patients with AIS≥6 were included in the insomnia group,and the incidence of insomnia was 19%(19/100).The remaining 81 patients were assigned to the non-insomnia *** were significant differences between the two groups in the GDA-7,GDS-15,MUNSH,BI,MFS,and SF-36 items(Pling(P<0.05).Subjective well-being and quality of life were poorer in the insomnia group than in the control *** AIS scores positively correlated with the GAD-7,GDS-15,and MFS scores in elderly hospitalized patients with insomnia(P<0.05).Logistic regression analysis showed that GDS-15≥5 was an independent risk factor for ins

关键词： Elderly hospitalized patients Insomnia Self-reported outcomes Symptoms Subjective feelings Correlation

Recent Advance in Electrocatalytic Water Splitting for Hydrogen Production by Layered Double Hydroxides

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2024年第4期40卷 577-589页

作者： xia Tian REN Qinghui YANG Jiangrong LI Zhenhua shao Mingfei DUAN Xue State Key Laboratory of Chemical Resource Engineering College of ChemistryBeijing University of Chemical TechnologyBeijing100029P.R.China Quzhou Institute for Innovation in Resource Chemical Engineering Quzhou324000P.R.China

Collecting green hydrogen(H2)from water splitting driven by renewable energy is a new competition to implement the construction of H2 energy industry and promote new economic growth for global *** common strategy to enhance the efficiency of H2 production is to reduce the potential of electrolytic cell that is the mainstream way to prepare efficient *** double hydroxides(LDHs)are one of the most active electrocatalysts with adjustable active sites in contemporary *** this review,we discuss the recent advanced progress of LDHs for hydrogen evolution reaction(HER)on cathode and oxygen evolution reaction(OER)or organic oxidation on anode and emphasize the influence of LDHs structure regulation in water electrolysis process(HER/OER)as well as the current development status of organic oxidation catalyzed by active oxygen species on ***,we propose the current challenges of LDHs in electrocatalysis and prospect their developing tendency and further application.

关键词： Layered double hydroxide Hydrogen production Hydrogen evolution reaction(HER) Oxygen evolution reaction(OER) Electrocatalytic organic oxidation

Enhancement of low-temperature toughness of Fe-Mn-C-Al alloy by rare earth Ce-modified inclusions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第1期31卷 157-173页

作者： Guang-kai Yang Chang-ling Zhuang Yi-zhuang Li Chen Hu shao-bo Li College of Materials and Metallurgy Guizhou UniversityGuiyang550025GuizhouChina Department of Mechanical Engineering University of Hong KongHong Kong999077China The State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Public Big Data Guizhou UniversityGuiyang550025GuizhouChina

Fe-Mn-C-Al alloys have been recognized as promising materials for certain low-temperature applications due to their exceptional mechanical properties and ***,their limited low-temperature toughness restricts their large-scale applications in specific *** influence of trace amounts of rare earth cerium(Ce)on the low-temperature toughness of Fe-18Mn-0.6C-1.8Al alloys was *** addition of Ce effectively alters the inclu-sions in the alloy,transforming large-sized irregular inclusions into fine ellipsoidal rare earth *** leads to a significant reduction in both the proportion and average size of the inclusions,resulting in their effective dispersion throughout the matrix and improved cryogenic *** presence of Ce-containing inclusions within the matrix reduces stress concentration,thereby inhibiting microcrack formation and improving impact absorption ***-cally,the addition of rare earth Ce alters the fracture behavior of the material at room temperature and low temperature,changing from brittle cleavage fracture to a more ductile failure *** impact toughness of the Fe-Mn-C-Al alloy is significantly improved by the addition of 0.0048 wt.%Ce,particularly at-196℃where the impact toughness reaches 103.6 J/cm^(2),representing an impressive improvement of 87.3%.

关键词： Fe-Mn-C-Al alloy Rare earth Low-temperature toughness Inclusion Fracture

Tilapia Head Glycolipid Alleviates Indomethacin-Induced Gastric Ulcer via Regulating Oxidative Stress and Inflammation Through COX/PGE2 Signaling Pathway in Adult Rats

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2024年第3期23卷 743-754页

作者： WANG Bohui WU Haixing shao Mingyang JIANG Mengqi SU Ruiheng GAO xia xia Guanghua SHI Haohao SHEN Xuanri Hainan Engineering Research Center of Aquatic Resources Efficient Utilization in South China Sea College of Food Science and TechnologyHainan UniversityHaikou 570228China Collaborative Innovation Center of Marine Food Deep Processing Dalian Polytechnic UniversityDalian 116000China College of Food and Engineering Hainan Tropical Ocean UniversitySanya 572022China

The aim of this experiment was to investigate the ameliorative effect and molecular mechanism of tilapia head glycolipid(TH-GL)on indomethacin(IDM)-induced gastric ulcer in male Sprague Dawley(SD)*** gastric ulcer model was established by oral administration of 30mgkg^(-1) IDM after 7 days of TH-GL or omeprazole(OME)administration in *** the macroscopic gastric injury symptoms,gastric mucosa protective factor cyclooxygenase 1(COX-1),cyclooxygenase 2(COX-2),prostaglandin E_(2)(PGE_(2)),the levels of oxidative stress,and inflammatory cytokine expression levels in the rats were *** experimental results showed that multiple ulcers appeared on the gastric surface of the rats in the model *** to the model group,TH-GL significantly alleviated gastric ulcers and reduced the gastric damage index in *** addition,TH-GL significantly promoted the expression of constitutive enzyme COX-1 while inhibited the expression of inducible enzyme COX-2,and make PGE2 maintain at normal ***-GL also inhibited oxidative stress and inflammatory responses,increased superoxide dismutase(SOD)activity and glutathione(GSH)content,decreased the level of malondialdehyde(MDA)and the content of pro-inflammatory *** conclusion,these results suggested that TH-GL could maintain the expression levels of COX-1 and PGE2 while inhibit the expression of COX-2 in the gastric of rat and then prevent IDM-induced gastric ulcer,which may be related to the regulation of oxidative stress and inflammatory ***,TH-GL might be a new option for the prevention of gastric diseases induced by IDM.

关键词： tilapia head glycolipid indomethacin gastric ulcer oxidative stress inflammation

In^(3+)-doped Sr_(2)Fe_(1.5)Mo_(0.5)O_(6−δ)cathode with improved performance for an intermediate-temperature solid oxide fuel cell

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第1期17卷 407-415页

作者： Yumei Ma Lijie Zhang Kang Zhu Binze Zhang Ranran Peng Changrong xia ling Huang State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources College of ChemistryXinjiang UniversityUrumqi 830046China Department of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China

Promoting the oxygen reduction reaction(ORR)is critical for commercialization of intermediate-temperature solid oxide fuel cells(IT-SOFCs),where Sr_(2)Fe_(1.5)Mo_(0.5)O_(6)−δ(SFM)is a promising cathode by working as a mixed ionic and electronic *** this work,doping of In^(3+)greatly increases the oxygen vacancy concentration and the content of adsorbed oxygen species in Sr_(2)Fe_(1.5)Mo_(0.5−x)InxO_(6−δ)(SFMInx),and thus effectively promotes the ORR *** a typical example,SFMIn_(0.1)reduces the polarization resistance(R_(p))from 0.089 to 0.046Ω∙cm^(2)at 800°C,which is superior to those doped with other metal *** addition,SFMIn0.1 increases the peak power density from 0.92 to 1.47 W∙cm^(−2)at 800°C with humidified H_(2)as the fuel,indicating that In3+doping at the Mo site can effectively improve the performance of SOFC cathode material.

关键词： solid oxide fuel cell cathode In3+doping oxygen reduction reaction(ORR) Sr_(2)Fe_(1.5)Mo_(0.5)O_(6-δ)