检索结果-南通市图书馆

Design and Experimental Verification of a Roll Control Strategy for Large Wingspan Flapping-Wing Aerial Vehicle

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic Engineering 2024年第4期21卷 1644-1661页

作者： Rui Meng Bifeng Song Jianlin xuan xiaojun Yang Dong xue School of Aeronautics Northwestern Polytechnical UniversityXi’an710072China Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen518057China Yangtze River Delta Research Institute of Northwestern Polytechnical University Taicang215400China

Most flapping-wing aircraft wings use a single degree of freedom to generate lift and thrust by flapping up and down,while relying on the tail control surfaces to manage ***,these aircraft have certain limitations,such as poor accuracy in attitude control and inadequate roll control *** paper presents a design for an active torsional mechanism at the wing's trailing edge,which enables differential variations in the pitch angle of the left and right wings during *** simple mechanical form significantly enhances the aircraft's roll control *** experimental verification of this mechanism was conducted in a wind tunnel using the RoboEagle flapping-wing aerial vehicle that we *** study investigated the effects of the control strategy on lift,thrust,and roll moment during flapping ***,the impact of roll control on roll moment was examined under various wind speeds,flapping frequencies,angles of attack,and wing ***,several rolling maneuver flight tests were performed to evaluate the agility of RoboEagle,utilizing both the elevon control strategy and the new roll control *** results demonstrated that the new roll control strategy effectively enhances the roll control capability,thereby improving the attitude control capabilities of the flapping-wing aircraft in complex wind field *** conclusion is supported by a comparison of the control time,maximum roll angle,average roll angular velocity,and other relevant parameters between the two control strategies under identical roll control input.

关键词： Roll control Bio-inspired Roll moment Flapping wing aerial vehicle

Coordination of distinctive pesticide adjuvants and atomization nozzles on droplet spectrum evolution for spatial drift reduction

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第2期66卷 250-262页

作者： Shidong xue Jingkun Han xi xi Zhong Lan Rongfu Wen xuehu Ma State Key Laboratory of Fine Chemicals Liaoning Key Laboratory of Clean Utilization of Chemical ResourcesInstitute of Chemical EngineeringSchool of Chemical EngineeringDalian University of TechnologyDalian 16024China School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong Kong 999077China China Tianchen Engineering Corporation Tianjin 300400China School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China

Pesticide adjuvants,as crop protection products,have been widely used to reduce drift loss and improve utilization efficiency by regulating droplet ***,the coordinated regulation mechanisms of adjuvants and nozzles on droplet spectrum remain ***,we established the relationship between droplet spectrum evolution and liquid atomization by investigating the typical characteristics of droplet diameter distribution near the *** on this,the regulation mechanisms of distinctive pesticide adjuvants on droplet spectrum were clarified,and the corresponding drift reduction performances were quantitively evaluated by wind tunnel *** shows that the droplet diameter firstly shifts to the smaller due to the liquid sheet breakup and then prefers to increase caused by droplet *** the surface tension of sprayed liquid facilitates the uniform liquid breakup and increasing the viscosity inhibits the liquid deformation,which prolong the atomization process and effectively improve the droplet *** a result,the drift losses of flat-fan and hollow cone nozzles are reduced by about 50%after adding organosilicon and vegetable oil *** contrast,the air induction nozzle shows a superior anti-drift ability,regardless of distinctive *** findings provide insights into rational adjuvant design and nozzle selection in the field application.

关键词： Pesticide drift Spray droplets Particle size distribution Spray atomization Transport processes Adjuvants

SFNet:Stellar Feature Network with CWT for Stellar Spectra Recognition

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第9期24卷 260-270页

作者： Hao Fu Peng Liu xuan Qi xue Mei College of Electrical Engineering and Control Science Nanjing Tech UniversityNanjing 211816China

Stellar spectral classification is crucial in astronomical data ***,existing studies are often limited by the uneven distribution of stellar samples,posing challenges in practical *** when balancing stellar categories and their numbers,there is room for improvement in classification *** study introduces a Continuous Wavelet Transform using the Super Morlet wavelet to convert stellar spectra into wavelet images.A novel neural network,the Stellar Feature Network,is proposed for classifying these *** spectra from Large Sky Area Multi-Object Fiber Spectroscopic Telescope DR9,encompassing five equal categories(B,A,F,G,K),were *** experiments validate the effectiveness of the proposed methods and network,achieving significant improvements in classification accuracy.

关键词： methods data analysis-techniques image processing-stars imaging-galaxies stellar content

Responses of growth performance,antioxidant function,small intestinal morphology and mRNA expression of jejunal tight junction protein to dietary iron in yellow-feathered broilers

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第4期23卷 1329-1337页

作者： Kaiwen Lei Hao Wu Jerry W Spears xi Lin xi Wang xue Bai Yanling Huang Key Laboratory of Animal Science of State Ethnic Affairs Commission Southwest Minzu UniversityChengdu 610041China Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization Southwest Minzu UniversityChengdu 610041China Department of Animal Science North Carolina State UniversityRaleighNC 27695-7621USA

This study aimed to investigate the dose-effect of iron on growth performance,antioxidant *** morphology,and mRNA expression of jejunal tight junction protein in 1-to21-d-old yellow-feathered broilers.A total of 7201-d-old yellow-feathered maleb roilers were allocated to 9 treatments with 8 replicate cages of 10 birds per *** dietary treatments were consisted of a basal diet(contained 79.6 mg Fe kg^(-1))supplemented with 0,20,40,60,80,160,320,640,and 1,280 mg Fe kg^(-1)in the form of FeSO_(4)·7H_(2)*** with the birds in the control group,birds supplemented with 20mg Fe kg^(-1)had higher average daily gain(ADG)(Pxidative stress,disrupted intestinal morphology,and reduced mRNA expression of jejunal tight junction protein.

关键词： iron yellow-feathered broiler antioxidant function intestinal morphology tight junction protein

Design and construction of charged-particle telescope array for study of exotic nuclear clustering structure

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第8期35卷 114-123页

作者： Zheng‑Li Liao xi‑Guang Cao Yu‑xuan Yang Chang‑Bo Fu xian‑Gai Deng Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Zhengzhou University Zhengzhou 450001China Key Laboratory of Nuclear Physics and Ion‑beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan University Shanghai 200438China

The exploration of exotic shapes and properties of atomic nuclei,e.g.,αcluster and toroidal shape,is a fascinating field in nuclear *** study the decay of these nuclei,a novel detector aimed at detecting multipleα-particle events was designed and *** detector comprises two layers of double-sided silicon strip detectors(DSSD)and a cesium iodide scintillator array coupled with silicon photomultipliers array as light sensors,which has the advantages of their small size,fast response,and large dynamic *** coupled with cesium iodide crystal arrays are used to distinguish multipleα*** detector array has a compact and integrated design that can be adapted to different experimental *** detector array was simulated using Geant4,and the excitation energy spectra of someα-clustering nuclei were reconstructed to demonstrate the *** simulation results show that the detector array has excellent angular and energy resolutions,enabling effective reconstruction of the nuclear excited state by multipleαparticle *** detector offers a new and powerful tool for nuclear physics experiments and has the potential to discover interesting physical phenomena related to exotic nuclear structures and their decay mechanisms.

关键词： Cluster decay Toroidal structure Telescope array SiPM Energy resolution

Significant contribution of carbonyls to atmospheric oxidation capacity(AOC)during the winter haze pollution over North China Plain

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第5期139卷 377-388页

作者： xue Yang Gen Zhang Guang Pan Guolan Fan Houyong Zhang xuan Ge Mingyue Du School of Municipal and Environmental Engineering Shandong Jianzhu UniversityJi’nan 250101China State Key Laboratory of Severe Weather&Key Laboratory of Atmospheric Chemistry of China Meteorological Administration Chinese Academy of Meteorological SciencesBeijing 100081China Shandong Jinan Ecological Environment Monitoring Center Ji’nan 250101China

Atmospheric carbonyl compounds play significant roles in the cycling of radicals and have exhibited surprisingly high levels in winter that were well correlated to particulate matter,for which the reason have not been clearly *** we measured carbonyl compounds and other trace gasses together with PM_(2.5)over urban Jinan in North China Plain during the *** higher carbonyl concentrations(average:14.63±4.21 ppbv)were found during wintertime haze pollution,about one to three-times relative to those on nonhaze days,with slight difference in chemical composition except formaldehyde(HCHO).HCHO(3.68 ppbv),acetone(3.17 ppbv),and acetaldehyde(CH_3CHO)(2.83 ppbv)were the three most abundant species,accounting for~75% of the total carbonylson both haze and non-haze *** from observational-based model(OBM)with atmospheric oxidation capacity(AOC)indicated that AOC significantly increased with the increasing carbonyls during the winter haze *** photolysis have supplied key oxidants such as RO_(2) and HO_(2),and thereby enhancing the formation of fine particles and secondary organic aerosols,elucidating the observed haze-carbonyls *** variation with carbonyls exhibiting peak values at early-noon and night highlighted the combined contribution of both secondary formation and primary diesel-fuel sources.1-butene was further confirmed to be the major precursor for *** study confirms the great contribution of carbonyls to AOC,and also suggests that reducing the emissions of carbonyls would be an effective way to mitigate haze pollution in urban area of the NCP region.

关键词： Carbonyls Haze Observation-based model Source apportionment Atmospheric oxidation capacity

Atmospheric iron deposition in a megacity of northwest China:Solubility,speciation,and deposition fluxes

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 383-393页

作者： xiaotao Yang Pingping Liu Zhiwei xue Hao Zhang xuan Li Hongmei Xu Zhenxing Shen Department of Environmental Science and Engineering Xi'an Jiaotong UniversityXi'anChina State Key Laboratory of Loess and Quaternary National Key R&D of China Geology Institute of Earth EnvironmentChinese Academy of SciencesXi'anChina No.203 Research Institute of Nuclear Industry Xi'an710086China xi'an Environmental Monitoring Station Xi'an 710054China

Atmospheric iron has crucial effects on biogeochemical cycles,atmospheric processing,global climate,and human *** this study,atmospheric dustfall samples were collected from six functional areas in xi'an,China,from 2020 to *** spatiotemporal distributions and deposition fluxes of total and water-soluble(ws)Fe as well as the speciation and potential sources of ws-Fe were *** areas had the highest concentrations of total Fe and ws-Fe,which were mainly due to copious emissions of heavy metals during *** total Fe concentrations peaked in spring,primarily due to the substantial input of crustal dust,which also led to the lowest Fe solubility in this *** contrast,the highest levels of ws-Fe occurred during winter due to an increase in biomass *** the water-soluble forms,ws-Fe(II)was dominant and accounted for 74.8%of the total amount of *** dust was the main contributor to total Fe,whereas biomass burning primarily contributed to peak ws-Fe *** average total and ws-Fe deposition fluxes in xi'an were the highest in spring and lowest in autumn,which were related to the distributions of the dustfall deposition fluxes and their Fe contents during these *** study provided a broader and comprehensive understanding of atmospheric iron deposition in Chinese urban area,which is of positive significance for understanding atmospheric chemistry and global climate change.

关键词： Atmospheric dustfall Iron Speciation distribution Seasonal variation Functional area Sources

Corporate Credit Ratings Based on Hierarchical Heterogeneous Graph Neural Networks

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Machine Intelligence Research 2024年第2期21卷 257-271页

作者： Bo-Jing Feng xi Cheng Hao-Nan Xu Wen-Fang xue Center for Research on Intelligent Perception and Computing National Laboratory of Pattern RecognitionInstitute of AutomationChinese Academy of SciencesBeijing 100190China

order to help investors understand the credit status of target corporations and reduce investment risks,the corporate credit rating model has become an important evaluation tool in the financial *** models are based on statistical learning,machine learning and deep learning especially graph neural networks(GNNs).However,we found that only few models take the hierarchy,heterogeneity or unlabeled data into account in the actual corporate credit rating ***,we propose a novel framework named hierarchical heterogeneous graph neural networks(HHGNN),which can fully model the hierarchy of corporate features and the heterogeneity of relationships between *** addition,we design an adversarial learning block to make full use of the rich unlabeled samples in the financial *** experiments conducted on the public-listed corporate rating dataset prove that HHGNN achieves SOTA compared to the baseline methods.

关键词： Corporate credit rating hierarchical relation heterogeneous graph neural networks adversarial learning

Catalytic effect in lithium metal batteries: From heterogeneous catalyst to homogenous catalyst

维普期刊数据库评论

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 Energy Chemistry 2024年第3期90卷 305-326,I0008页

作者： Haining Fan xuan-Wen Gao Hailong Xu Yichun Ding Shi-xue Dou Wen-Bin Luo School of Fashion and Textiles The Hong Kong Polytechnic UniversityHong Kong 100872China Institute for Energy Electrochemistry and Urban Mines Metallurgy School of MetallurgyNortheastern UniversityShenyang 110819LiaoningChina Institute of Energy Materials Science University of Shanghai for Science and TechnologyShanghai 200000China State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710000ShaanxiChina

Lithium metal batteries are regarded as prominent contenders to address the pressing needs owing to the high theoretical *** the broader implementation,the primary obstacle lies in the intricate multi-electron,multi-step redox reaction associated with sluggish conversion kinetics,subsequently giving rise to a cascade of parasitic *** order to smooth reaction kinetics,catalysts are widely introduced to accelerate reaction rate via modulating the energy *** past decades,a large amount of research has been devoted to the catalyst design and catalytic mechanism exploration,and thus the great progress in electrochemical performance has been ***,it is necessary to make a comprehensive review toward key progress in catalyst design and future development *** this review,the basic mechanism of lithium metal batteries is provided along with corresponding advantages and existing challenges detailly *** main catalysts employed to accelerate cathode reaction with emphasis on their catalytic mechanism are summarized as ***,the rational design and innovative direction toward efficient catalysts are suggested for future application in metal-sulfur/gas battery and *** review is expected to drive and benefit future research on rational catalyst design with multi-parameter synergistic impacts on the activity and stability of next-generation metal battery,thus opening new avenue for sustainable solution to climate change,energy and environmental issues,and the potential industrial economy.

关键词： Energy storage and conversion Metal battery Sulfur battery Air battery Catalytic effect Heterogeneous catalyst Homogeneous catalyst