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Distributed collaborative complete coverage path planning based on hybrid strategy

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Journal of Systems Engineering and Electronics 2024年第2期35卷 463-472页

作者： ZHANG Jia DU xin DONG Qichen xin Bin School of Automation Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Autonomous Intelligent Unmanned Systems Beijing Institute of TechnologyBeijing 100081China

Collaborative coverage path planning(CCPP) refers to obtaining the shortest paths passing over all places except obstacles in a certain area or space. A multi-unmanned aerial vehicle(UAV) collaborative CCPP algorithm is proposed for the urban rescue search or military search in outdoor *** to flexible control of small UAVs, it can be considered that all UAVs fly at the same altitude, that is, they perform search tasks on a two-dimensional plane. Based on the agents’ motion characteristics and environmental information, a mathematical model of CCPP problem is established. The minimum time for UAVs to complete the CCPP is the objective function, and complete coverage constraint, no-fly constraint, collision avoidance constraint, and communication constraint are considered. Four motion strategies and two communication strategies are designed. Then a distributed CCPP algorithm is designed based on hybrid strategies. Simulation results compared with patternbased genetic algorithm(PBGA) and random search method show that the proposed method has stronger real-time performance and better scalability and can complete the complete CCPP task more efficiently and stably.

关键词： multi-agent cooperation unmanned aerial vehicles(UAV) distributed algorithm complete coverage path planning(CCPP)

GPa-level pressure-induced enhanced corrosion resistance in TiZrTaNbSn biomedical high-entropy alloy

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China Foundry 2024年第3期21卷 265-275页

作者： Xiao-hong Wang Yu-lei Deng Qiao-yu Li Zhi-xin Xu Teng-fei Ma xing Yang Duo Dong Dong-dong Zhu Xiao-hong Yang Key Laboratory of Air-driven Equipment Technology of Zhejiang Province Quzhou UniversityQuzhou 324000ZhejiangChina School of Materials Science and Engineering Taizhou UniversityTaizhou 318000ZhejiangChina

TiZrTaNb-based high-entropy alloys(HEAs)are research frontier of biomedical materials due to their high hardness,good yield strength,excellent wear resistance and corrosion ***,as an essential trace element in the human body that plays a significant role in physiological *** has stable chemical properties and a low elastic *** this study,a new material,TiZrTaNbSn HEAs,was proposed as a potential biomedical *** Ti_(35)Zr_(25)Ta_(15)Nb_(15)Sn_(10)biomedical high-entropy alloys(BHEAs)were successfully prepared through an arc melting furnace and then remelted using a German high-temperature and high-pressure apparatus under GPa-level(4 GPa and 7 GPa).The precipitation behavior of the needle-like HCP-Zr_(5)Sn_(3)phase that precipitates discontinuously at the grain boundary was successfully *** phase constitution,microstructure,and corrosion resistance of the alloy were *** results show that the needle-like HCP-Zr_(5)Sn_(3)phase is eliminated and the(Zr,Sn)-rich nano-precipitated phase is precipitated in the microstructure under high pressure,which leads to the narrowing of grain boundaries and consequently improves the corrosion resistance of the *** addition,the formation mechanisms of(Zr,Sn)-rich nanoprecipitates in BHEAs were *** Zr and Sn dissolve in the matrix due to the effect of high pressure,during the cooling process,they precipitate to form a(Zr,Sn)-rich nano-precipitated phase.

关键词： biomedical HEAs precipitation grain boundary corrosion resistance TiZrTaNbSn

Effect of brazing temperature on microstructure and tensile strength ofγ-TiAl joint vacuum brazed with micro-nano Ti−Cu−Ni−Nb−Al−Hf filler

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Transactions of Nonferrous Metals Society of China 2024年第8期34卷 2563-2574页

作者： Li LI Yu-tong CHEN lei-xin YUAN Fen LUO Zhi-xue FENG Xiao-qiang LI School of Materials Science and Engineering East China Jiaotong UniversityNanchang 330013China State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang 330013China National Engineering Research Center of Near-net-shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510640China

A novel micro-nano Ti−10Cu−10Ni−8Al−8Nb−4Zr−1.5Hf filler was used to vacuum braze Ti−47Al−2Nb−2Cr−0.15B alloy at 1160−1220°C for 30 *** interfacial microstructure and formation mechanism of TiAl joints and the relationships among brazing temperature,interfacial microstructure and joint strength were emphatically *** show that the TiAl joints brazed at 1160 and 1180°C possess three interfacial layers and mainly consist ofα2-Ti3Al,τ3-Al3NiTi2 and Ti2Ni,but the brazing seams are no longer layered and Ti2Ni is completely replaced by the uniformly distributedτ3-Al3NiTi2 at 1200 and 1220°C due to the destruction ofα2-Ti3Al barrier *** transformation at 1200°C obviously improves the tensile strength of the joint and obtains a maximum of 343 ***,the outward diffusion of Al atoms from the dissolution of TiAl substrate dominates the microstructure evolution and tensile strength of the TiAl joint at different brazing temperatures.

关键词： γ-TiAl alloy micro-nano filler vacuum brazing interfacial microstructure tensile strength

TL1A Promotes Fibrogenesis in Colonic Fibroblasts via the TGF-β1/Smad3 Signaling Pathway

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Current Medical Science 2024年第3期44卷 519-528页

作者： Jia SONG Dong-lei SUN Chen-yang LI Yu-xin LUO Qian LIU Yue YAO Hong ZHANG Ting-ting YANG Mei SONG xin-li BAI Xiao-lan ZHANG Department of Gastroenterology The Second Hospital of Hebei Medical UniversityHebei Key Laboratory of GastroenterologyHebei Institute of GastroenterologyHebei Clinical Research Center for Digestive DiseasesShijiazhuang050000China Department of Pediatrics The Second Hospital of Hebei Medical UniversityShijiazhuang050000China

Objective Intestinal fibrosis is a refractory complication of inflammatory bowel disease(IBD).Tumor necrosis factor ligand-related molecule-1A(TL1A)is important for IBD-related intestinal fibrosis in a dextran sodium sulfate(DSS)-induced experimental colitis *** study aimed to explore the effects of TL1A on human colonic *** A trinitrobenzene sulfonic acid(TNBS)-induced experimental colitis model of LCK-CD2-TL1A-GFP transgenic(Tg)or wild-type(WT)mice was established to determine the effect and mechanism of TL1A on intestinal *** human colonic fibroblast CCD-18Co cell line was treated concurrently with TL1A and human peripheral blood mononuclear cell(PBMC)*** proliferation and activation of CCD-18Co cells were detected by BrdU assays,flow cytometry,immunocytochemistry and Western *** metabolism was tested by Western blotting and real-time quantitative polymerase chain reaction(RT-qPCR).Results The level of collagen metabolism in the TNBS+ethyl alcohol(EtOH)/Tg group was greater than that in the TNBS+EtOH/WT *** growth factor-β1(TGF-β1)and p-Smad3 in the TNBS+EtOH/Tg group were upregulated as compared with those in the TNBS+EtOH/WT *** proliferation of CCD-18Co cells was promoted by the addition of human PBMC supernatant supplemented with 20 ng/mL TL1A,and the addition of human PBMC supernatant and TL1A increased CCD-18Co proliferation by 24.4%at 24 ***1A promoted cell activation and increased the levels of COL1A2,COL3A1,and TIMP-1 in CCD-18Co *** of CCD-18Co cells with TL1A increased the expression of TGF-β1 and *** TL1A promotes TGF-β1-mediated intestinal fibroblast activation,proliferation,and collagen deposition and is likely related to an increase in the TGF-β1/Smad3 signaling pathway.

关键词： tumor necrosis factor ligand-related molecule-1A fibrosis inflammatory bowel disease myofibroblasts transforming growth factor-β1

Mechanochemical route to fabricate an efficient nitrate reduction electrocatalyst

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Nano Research 2024年第6期17卷 4889-4897页

作者： Yunliang Liu Zhiyu Zheng Sobia Jabeen Naiyun Liu Yixian Liu Yuanyuan Cheng Yaxi Li Jingwen Yu xin Wu Nina Yan lei Xu Haitao Li Institute for Energy Research School of Energy and Power EngineeringJiangsu UniversityZhenjiang 212013China Jiangsu Engineering Technology Research Center of Biomass Composites and Addictive Manufacturing Institute of Agricultural Facilities and EquipmentJiangsu Academy of Agricultural SciencesNanjing 210014China Key Laboratory for Protected Agricultural Engineering in the Middle and Lower Reaches of Yangtze River Ministry of Agriculture and Rural AffairsNanjing 210014China

The electrochemical nitrate reduction reaction(NO_(3)RR)to ammonia under ambient conditions is a promising approach for addressing elevated nitrate levels in water bodies,but the progress of this reaction is impeded by the complex series of chemical reactions involving electron and proton transfer and competing hydrogen evolution ***,it becomes imperative to develop an electro-catalyst that exhibits exceptional efficiency and remarkable selectivity for ammonia synthesis while maintaining long-term *** the magnetic biochar(Fe-C)has been synthesized by a two-step mechanochemical route after a pyrolysis treatment(450,700,and 1000℃),which not only significantly decreases the particle size,but also exposes more oxygen-rich functional groups on the surface,promoting the adsorption of nitrate and water and accelerating electron transfer to convert it into *** showed that the catalyst(Fe-C-700)has an impressive NH_(3)production rate of 3.5 mol·h^(−1)·gcat^(−1),high Faradaic efficiency of 88%,and current density of 0.37 A·cm^(−2)at 0.8 V *** hydrogen electrode(RHE).In-situ Fourier transform infrared spectroscopy(FTIR)is used to investigate the reaction intermediate and to monitor the *** oxygen functionalities on the catalyst surface activate nitrate ions to form various intermediates(NO_(2),NO,NH_(2)OH,and NH_(2))and reduce the rate determining step energy barrier(*NO_(3)→*NO_(2)).This study presents a novel approach for the use of magnetic biochar as an electro-catalyst in NO_(3)RR and opens the road for solving environmental and energy challenges.

关键词： mechanochemical route magnetic biochar electron transfer nitrate ammonia

Clinical efficacy of endovascular revascularization combined with vacuum-assisted closure for the treatment of diabetic foot

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World Journal of Diabetes 2024年第7期15卷 1499-1508页

作者： Feng-Rui lei Xiao-Fei Shen Chuang Zhang xin-Qing Li Hao Zhuang Hong-Fei Sang Department of Vascular Surgery The Second Affiliated Hospital of Soochow UniversitySuzhou 215004Jiangsu ProvinceChina

BACKGROUND The diabetic foot is a common cause of disability and death,and comorbid foot infections usually lead to prolonged hospitalization,high healthcare costs,and a significant increase in amputation *** most diabetic foot trauma is complicated by lower extremity arteriopathy,which becomes an independent risk factor for major amputation in diabetic foot *** To establish the efficacy and safety of endovascular revascularization(ER)combined with vacuum-assisted closure(VAC)for the treatment of diabetic *** Clinical data were collected from 40 patients with diabetic foot admitted to the Second Affiliated Hospital of Soochow University from April 2018 to April *** foot lesions were graded according to Wagner’s classification,and blood flow to the lower extremity was evaluated using the ankle-brachial index test and computerized tomography angiography of the lower extremity *** subcutaneous insulin infusion pumps were used to achieve glycemic *** limb revascularization was facilitated by percutaneous transluminal balloon angioplasty(BA)or *** were cleaned by nibbling *** granulation tissue growth was induced by VAC,and wound repair was performed by skin grafting or skin flap *** Of the 35 cases treated with lower limb revascularization,34 were successful with a revascularization success rate of 97%.Of these,6 cases underwent stenting after BA of the superficial femoral artery,and 1 received popliteal artery stent *** the 25 cases treated with infrapopliteal artery revascularization,39 arteries were reconstructed,7 of which were treated by drug-coated BA and the remaining 32 with plain old *** was performed in 32 ***-four cases of skin grafting and 2 cases of skin flap transplantation were *** patients underwent major amputations,whereas 17 had minor amputations,accounting for a success limb salvage rate of 95%.CONCLUSION ER in

关键词： Diabetic foot Revascularization Vacuum-assisted closure Balloon angioplasty Wound repair

Controllable nucleation and deformation of skyrmions on surface of magnetic nanotubular monolayer

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Rare Metals 2024年第7期43卷 3250-3259页

作者： xin-xin Zhang Chen-Yu Zhang Yi-xin xing Chao Man Jiao Liu Yong Hu Department of Physics College of SciencesNortheastern UniversityShenyang 110819China School of Materials and Mineral Resources Engineering Universiti Sains MalaysiaEngineering Campus14300 Nibong TebalPenangMalaysia State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China

Magnetic skyrmions emerge when the energy of ferromagnetic exchange interaction promoting parallel alignment of spins enters in competition with energies favoring non-collinear alignment of spins such as Dzy aloshinskii-Moriya interaction(DMI),long-rang dipole-dipole interaction(DDI),or higher-order exchange *** perform an unbiased Monte Carlo simulation to study the DMI-based skyrmion nucleation and stabilization on the surface of magnetic nanotubular monolayer controlled by tuning constants of DDI(g) and next-nearest-neighbor antiferromagnetic exchange interaction(j') with appropriate *** g and j',the loosely distributed skyrmions initially nucleate on the surface of nanotube approaching to the magnetic field(h) direction with increasing h in the intermediate ***,the skyrmion size,shape,density,distribution and crystal structure,as well as its driven field range,are tailored by g and j'.This work demonstrates the skyrmion nucleation mechanisms in three-dimensional magnetic nanostructures with curvature effect and multiple interactions,serving as a benchmark for a guide to experimentalists for preparation of samples in magnetic skyrmion states.

关键词： Magnetic nanotube Magnetic skyrmion Dzyaloshinskii-Moriya interaction Dipole-dipole interaction Monte Carlo simulation

Simulation and evaluation study of atmospheric aerosol nonsphericity as a function of particle size

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Particuology 2024年第7期90卷 281-291页

作者： Qianjun Mao xin Nie School of Urban Construction Wuhan University of Science and TechnologyWuhan430065China College of New Energy and Materials Northeast Petroleum UniversityDaqing163318China

Aerosol nonsphericity causes great uncertainty in radiative forcing assessments and climate *** considerable studies have attempted to quantify this uncertainty,the relationship between aerosol nonsphericity and particle size is usually not considered,thus reducing the accuracy of the *** this study,a coupled inversion algorithm combining an improved stochastic particle swarm optimization algorithm and angular light scattering is used for the nonparametric estimation of aerosol nonsphericity variation with particle size,and the optimal sample selection method is employed to screen the *** on the verification of inversion accuracy,the variation of aerosol aspect ratio with particle size based on the ellipsoidal model in global regions has been obtained from Aerosol Robotic Network(AERONET)data,and the effect of nonsphericity on radiative forcing and dry deposition has been *** results show that the aspect ratio increases with particle size in all regions,with the maximum ranging from 1.4 to 1.8 in the desert,reflecting the differences in aerosol composition at different particle *** radiation calculations,considering aerosol nonsphericity makes the aerosol cooling effect weaker and surface radiative fluxes increase,but hardly changes the aerosol absorption,with maximum differences of 9.22%and 22.12%at the bottom and top of the atmosphere,***,the differences in radiative forcing between aspect ratios as a function of particle size and not varying with particle size are not significant,averaging less than 2%.Besides,the aspect ratio not varying with particle size underestimates the deposition velocity of small particles and overestimates that of large particles compared to that as a function of particle size,with maximum differences of 7%and 4%,respectively.

关键词： Aerosol nonsphericity Inversion Aspect ratio Radiative forcing Dry deposition velocity

Dominant woody plant species recognition with a hierarchical model based on multimodal geospatial data for subtropical forests

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Journal of Forestry Research 2024年第3期35卷 111-130页

作者： xin Chen Yujun Sun State Forestry&Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry UniversityBeijing 100083People's Republic of China

Since the launch of the Google Earth Engine(GEE)cloud platform in 2010,it has been widely used,leading to a wealth of valuable ***,the potential of GEE for forest resource management has not been fully *** extract dominant woody plant species,GEE combined Sen-tinel-1(S1)and Sentinel-2(S2)data with the addition of the National Forest Resources Inventory(NFRI)and topographic data,resulting in a 10 m resolution multimodal geospatial dataset for subtropical forests in southeast *** and texture features,red-edge bands,and vegetation indices of S1 and S2 data were computed.A hierarchical model obtained information on forest distribution and area and the dominant woody plant *** results suggest that combining data sources from the S1 winter and S2 yearly ranges enhances accuracy in forest distribution and area extraction compared to using either data source ***,for dominant woody species recognition,using S1 winter and S2 data across all four seasons was *** terrain factors and removing spatial correlation from NFRI sample points further improved the recognition *** optimal forest extraction achieved an overall accuracy(OA)of 97.4%and a maplevel image classification efficacy(MICE)of 96.7%.OA and MICE were 83.6%and 80.7%for dominant species extraction,*** high accuracy and efficacy values indicate that the hierarchical recognition model based on multimodal remote sensing data performed extremely well for extracting information about dominant woody plant *** the results using the GEE application allows for an intuitive display of forest and species distribution,offering significant convenience for forest resource monitoring.

关键词： Google Earth Engine Sentinel Forest resource inventory data Dominant woody plant species Subtropics Model performance