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Predicting submerged vegetation drag with a machine learning-based method

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Journal of Hydrodynamics 2024年第3期36卷 534-545页

作者： Meng-yang Liu hong-wu Tang Sai-yu Yuan Jing Yan College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Key Laboratory of Hydrologic-Cycle and Hydrodynamic-System of Ministry of Water Resources Hohai UniversityNanjing210098China

Accurate estimation of the drag forces generated by vegetation stems is crucial for the comprehensive assessment of the impact of aquatic vegetation on hydrodynamic processes in aquatic *** coupling relationship between vegetation layer flow velocity and vegetation drag makes precise prediction of submerged vegetation drag forces particularly *** present study utilized published data on submerged vegetation drag force measurements and employed a genetic programming(GP)algorithm,a machine learning technique,to establish the connection between submerged vegetation drag forces and flow and vegetation *** using the bulk velocity,U,as the reference velocity scale to define the drag coefficient,C_(d),and stem Reynolds number,the GP runs revealed that the drag coefficient of submerged vegetation is related to submergence ratio(H^(*)),aspect ratio(d^(*)),blockage ratio(ψ^(*)),and vegetation density(λ).The relation between vegetation stem drag forces and flow velocity is implicitly embedded in the definition of C_(d).Comparisons with experimental drag force measurements indicate that using the bulk velocity as the reference velocity,as opposed to using the vegetation layer average velocity,U_(v),eliminates the need for complex iterative processes to estimate U_(v)and avoids introducing additional errors associated with U_(v)*** approach significantly enhances the model’s predictive capabilities and results in a simpler and more user-friendly formula expression.

关键词： Drag coefficient genetic programming algorithm submerged vegetation flow resistance cylinder array

Group-wise co-salient object detection via multi-view self-labeling novel class discovery

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Frontiers of Computer Science 2024年第2期18卷 259-261页

作者： Yang wu Gang DONG Lingyan liang Yaqian ZHAO Kaihua ZHANG Inspur Electronic Information Industry Co. Ltd.Beijing 100080China Jiangsu Key Laboratory of Big Data Analysis Technology and Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science and TechnologyNanjing 210044China

1 Introduction Co-salient object detection(CoSOD)aims to extract the salient object(s)that are common across a group of relevant images[1].Group-wise clue plays a crucial role in accurately predicting the co-salient ***,numerous groupwise deep models have been proposed by exploring consistency across images in unsupervised clustering manners[2-4]or the semantic connections guidance information[5].

关键词： consistency Group semantic

Track-Pattern-Based Characteristics of Extratropical Transitioning Tropical Cyclones in the Western North Pacific

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Advances in Atmospheric Sciences 2024年第6期41卷 1251-1263页

作者： hong HUANG Dan wu Yuan WANG Zhen WANG Yu LIU College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China No.31631 Army of PLA Huizhou 516000China School of Atmospheric Sciences and Key Laboratory of Mesoscale Severe Weather/Ministry of Education Nanjing 210023China No.93721 Army of PLA Shuozhou 038300China

Based on the Regional Specialized Meteorological Center(RSMC)Tokyo-Typhoon Center best-track data and the NCEP-NCAR reanalysis dataset,extratropical transitioning(ET)tropical cyclones(ETCs)over the western North Pacific(WNP)during 1951–2021 are classified into six clusters using the fuzzy c-means clustering method(FCM)according to their track *** characteristics of the six hard-clustered ETCs with the highest membership coefficient are *** tropical cyclones(TCs)that were assigned to clusters C2,C5,and C6 made landfall over eastern Asian countries,which severely threatened these *** landfalling TCs,93.2%completed their ET after landfall,whereas 39.8%of ETCs completed their transition within one *** frequency of ETCs over the WNP has decreased in the past four decades,wherein cluster C5 demonstrated a significant decrease on both interannual and interdecadal timescales with the expansion and intensification of the western Pacific subtropical high(WPSH).This large-scale circulation pattern is favorable for C2 and causes it to become the dominant track pattern,owning to it containing the largest number of intensifying ETCs among the six clusters,a number that has increased insignificantly over the past four *** surface roughness variation and three-dimensional background circulation led to C5 containing the maximum number of landfalling TCs and a minimum number of intensifying *** results will facilitate a better understanding of the spatiotemporal distributions of ET events and associated environment background fields,which will benefit the effective monitoring of these events over the WNP.

关键词： Western North Pacific tropical cyclone extratropical transition fuzzy c-means clustering method

Studying the co-evolution of information diffusion,vaccination behavior and disease transmission in multilayer networks with local and global effects

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Chinese Physics B 2024年第3期33卷 677-689页

作者：霍良安武兵杰 Business School University of Shanghai for Science and TechnologyShanghai 200093China School of Intelligent Emergency Management University of Shanghai for Science and TechnologyShanghai 200093China

Today,with the rapid development of the internet,a large amount of information often accompanies the rapid transmission of disease outbreaks,and increasing numbers of scholars are studying the relationship between information and the disease transmission process using complex *** fact,the disease transmission process is very *** this information,there will often be individual behavioral measures and other factors to *** of the previous research has aimed to establish a two-layer network model to consider the impact of information on the transmission process of disease,rarely divided into information and behavior,*** carry out a more in-depth analysis of the disease transmission process and the intrinsic influencing mechanism,this paper divides information and behavior into two layers and proposes the establishment of a complex network to study the dynamic co-evolution of information diffusion,vaccination behavior,and disease *** is achieved by considering four influential relationships between adjacent layers in multilayer *** the information layer,the diffusion process of negative information is described,and the feedback effects of local and global vaccination are *** the behavioral layer,an individual's vaccination behavior is described,and the probability of an individual receiving a vaccination is influenced by two factors:the influence of negative information,and the influence of local and global disease *** the disease layer,individual susceptibility is considered to be influenced by vaccination *** state transition equations are derived using the micro Markov chain approach(MMCA),and disease prevalence thresholds are *** is demonstrated through simulation experiments that the negative information diffusion is less influenced by local vaccination behavior,and is mainly influenced by global vaccination behavior;vaccination behavior is mainly influenced by local d

关键词： information diffusion vaccination behavior disease transmission multilayer networks local and global effect

Insight into the mechanism of 5-hydroxymethylfurfural electroreduction to 2,5-bis(hydroxymethyl)furan over Cu anchored N-doped carbon nanosheets

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Nano Research 2024年第9期17卷 7991-7999页

作者： Haoran wu Xinwei Chen Haishan Xu Runlu Yang Xin Wang Junying Chen Zhenbing Xie liang wu Yiyong Mai School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China School of Chemistry and Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgeingShanghai Jiao Tong UniversityShanghai 200240China Department of Chemistry Tangshan Normal UniversityTangshan 063000China

Design of non-noble metal electrocatalysts for biomass conversion to high-value chemicals and understanding the related catalytic mechanisms are of profound significance but have remained a major ***,we developed a novel biomass-derived electrocatalyst(denoted as Cu/NC),featuring with electron-deficient copper nanoparticles anchored on N-doped carbon nanosheets,for the electrochemical reduction of 5-hydroxymethylfurfural(HMF)to 2,5-bis(hydroxymethyl)furan(BHMF,a vital precursor of functional polymers).The optimized Cu/NC electrocatalyst exhibited an excellent performance with high Faradaic efficiency(89.5%)and selectivity(90.8%)of BHMF at a low concentration of HMF(18.1 mM).Even at a very high HMF concentration(108.6 mM),the Faraday efficiency and selectivity of BHMF could still reach 74.8%and 81.1%,*** performance approached those of the reported noble metal-based *** study revealed that the N doping in the Cu/NC catalyst could regulate the electronic structure of Cu,strengthening the adsorption of the HMF carbonyl group,and thus boosting the selectivity of ***,strong electronic metal-support interactions of Cu and the N-doped carbon support optimized the charge transfer rate,thus promoting the dissociation of water to the active hydrogen(H^(*))species and boosting the reaction kinetic rate of H^(*)and HMF.

关键词： biomass 5-hydroxymethylfurfural electrochemical reduction N-doped carbon materials 2,5-bis(hydroxymethyl)furan

“趣味”的角逐——论“十七年”诗人审美趣味的重塑及危机

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吉首大学学报（社会科学版） 2012年第1期33卷 79-83页

作者：巫洪亮龙岩学院文学与传媒学院福建龙岩364000

在"十七年"诗歌的成长过程中,诗人审美趣味的重塑不仅是知识分子实施自我革新和国家权力主体再造"新人"的有效手段,同时也是推进当代诗歌新的美学风格生成与建构的重要方略。当代诗坛的主持者们通过趣味的"区隔化"、阶级指认和合法趣味... 详细信息

在"十七年"诗歌的成长过程中,诗人审美趣味的重塑不仅是知识分子实施自我革新和国家权力主体再造"新人"的有效手段,同时也是推进当代诗歌新的美学风格生成与建构的重要方略。当代诗坛的主持者们通过趣味的"区隔化"、阶级指认和合法趣味的再生产等方式,根治了知识分子(诗人)的"审美偏执"和"审美惯性",促使当代诗人审美趣味"工农化"并最终走向权力化。由于这种不断"权力化"的审美趣味具有鲜明的排他性和授予性,不但造成当代诗歌"美学趣味"的变异与失衡,而且随着语境的变迁"工农兵"趣味也将遭遇合法性危机。

关键词： “十七年”诗歌审美趣味

Ultraviolet Photodetector based on Sr_(2)Nb_(3)O_(10) Perovskite Nanosheets

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Journal of wuhan University of Technology(Materials Science) 2024年第2期39卷 282-287页

作者：张斌斌 JIA Mengmeng liang Qi wu Jinsong ZHAI Junyi 李宝文 School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China CAS Center for Excellence in Nanoscience Beijing Institute of Nanoenergy and NanosystemsChinese Academy of SciencesBeijin 100083China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070China

Liquid-phase exfoliation was employed to synthesize Sr_(2)Nb_(3)O_(10) perovskite nanosheets with thicknesses down to 1.76 *** electron microscopy(TEM),atomic force microscope(AFM),X-ray photoelectron spectrometer(XPS),and other characterization techniques were used to evaluate the atomic structure and chemical composition of the exfoliated nanosheets.A UV photodetector based on individual Sr_(2)Nb_(3)O_(10) nanosheets was prepared to demonstrate the application of an ultraviolet(UV) *** UV photodetector exhibited outstanding photocurrent and responsivity with a responsivity of 3×10^(5) A·W^(-1) at 5 V bias under 280 nm illumination,a photocurrent of 60 nA,and an on/off ratio of 3×10^(2).

关键词： perovskite nanosheets liquid-phase exfoliation ultraviolet photodetector

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新型超声速旋流分离器设计及数值模拟

中国石油大学学报（自然科学版） 2010年第4期34卷 119-122,126页

作者：文闯曹学文吴梁红中国石油大学储运与建筑工程学院山东青岛266555

设计一种静态导向叶片安装在拉伐尔喷管之前，使流体经旋流后再进入拉伐尔喷管进行膨胀降温的新型超声速旋流分离器。新型超声速旋流分离器中气流的旋转发生在亚声速段，使得分离器内的激波更容易控制，降低能量损失，使液滴的再蒸发影... 详细信息

设计一种静态导向叶片安装在拉伐尔喷管之前，使流体经旋流后再进入拉伐尔喷管进行膨胀降温的新型超声速旋流分离器。新型超声速旋流分离器中气流的旋转发生在亚声速段，使得分离器内的激波更容易控制，降低能量损失，使液滴的再蒸发影响程度减小，从而提高分离器的分离性能及压力恢复能力。对新型超声速旋流分离器内流体的流动规律进行数值模拟研究。结果表明：随着升压比的增大，激波位置由扩压器向喷管方向移动，升压比控制在40％-73％内，超声速旋流分离器可正常工作；气流在拉伐尔喷管出口处形成低温、低压区，马赫数达到2．0，静温达-98．82℃，静压达82．945kPa；新型分离器内旋流场离心加速度可达243558g（g为重力加速度），能够实现良好的超声速气液旋流分离。

关键词：超声速旋流分离器升压比激波数值模拟

不同轮作模式下作物根际土壤养分及真菌群落组成特征

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环境科学 2020年第10期41卷 4682-4689页

作者：孙倩吴宏亮陈阜康建宏宁夏大学农学院银川750021 中国农业大学农学院农业部农作制度重点实验室北京100193

为研究宁夏中部干旱带不同轮作模式下土壤养分及真菌群落组成的特征,以谷子轮作大豆(MRG)、轮作籽粒苋(MRA)、轮作藜麦(MRQ)及谷子连作(CK)为对象,测定了土壤养分含量,并利用Illumina MiSeq高通量测序平台测定了土壤真菌的ITS变异区序列... 详细信息

为研究宁夏中部干旱带不同轮作模式下土壤养分及真菌群落组成的特征,以谷子轮作大豆(MRG)、轮作籽粒苋(MRA)、轮作藜麦(MRQ)及谷子连作(CK)为对象,测定了土壤养分含量,并利用Illumina MiSeq高通量测序平台测定了土壤真菌的ITS变异区序列.结果表明,不同轮作模式对土壤养分的影响存在差异.3种轮作模式下土壤pH和电导率均有所下降,土壤全氮、全钾、全磷和有机质含量均上升,OTUs数和α多样性指数均高于连作.真菌群落组成研究结果显示,子囊菌门(Ascomycota)为4种模式下的优势菌群.聚类分析显示MRA和MRG的真菌属组成最为相似,其次是MRQ,CK与3种轮作模式相差较大.相关性分析显示,土壤养分与几种优势真菌属呈显著相关性(P<0.05或P<0.01),土壤全氮、全钾、硝态氮和有机质含量是影响土壤真菌群落最主要的因子.主成分分析(PCA)表明,MRG轮作模式优于MRA和MRQ模式.综上所述,轮作提高了真菌群落多样性指数,改变了土壤真菌群落结构,改善了土壤肥力状况,其中以谷子与大豆轮作效果最佳,建议将谷豆轮作作为中部干旱带杂粮产业中主要的轮作模式之一进行推广.

关键词：谷子轮作模式土壤养分真菌群落组成宁夏中部干旱带