检索结果-南通市图书馆

Multiscale Characteristics and Connection Mechanisms of Attraction Networks:A Trajectory Data Mining Approach leveraging Geotagged Data

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 Geographical Science 2024年第3期34卷 533-547页

作者： JIANG hongqiang WEI Ye MEI lin WANG Zhaobo School of Resource and Environment Engineering Ludong UniversityYantai 264025China School of Geographical Sciences Northeast Normal UniversityChangchun 130024China Changchun University of Finance and Economics Changchun 130122China Jilin Jizhi City Architectural Design Co. LTDChangchun 130012China

Urban tourism is considered a complex system,and multiscale exploration of the organizational patterns of attraction networks has become a topical issue in urban tourism,so exploring the multiscale characteristics and connection mechanisms of attraction networks is important for understanding the linkages between attractions and even the future destination *** paper uses geotagging data to compare the links between attractions in Beijing,China during four different periods:the pre-Olympic period(2004–2007),the Olympic Games and subsequent‘heat period’(2008–2013),the post-Olympic period(2014–2019),and the COVID-19(Corona Virus Disease 2019)pandemic period(2020–2021).The aim is to better understand the evolution and patterns of attraction networks at different scales in Beijing and to provide insights for tourism planning in the *** results show that the macro,meso-,and microscales network characteristics of attraction networks have inherent logical relationships that can explain the commonalities and differences in the development process of tourism *** macroscale attraction network degree Matthew effect is significant in the four different periods and exhibits a morphological monocentric structure,suggesting that new entrants are more likely to be associated with attractions that already have high *** mesoscale links attractions according to the common purpose of tourists,and the results of the community segmentation of the attraction networks in the four different periods suggest that the functional polycentric structure describes their clustering effect,and the weak links between clusters result from attractions bound by incomplete information and distance,and the functional polycentric structure with a generally more efficient network of *** pattern structure at the microscale reveals the topological transformation relationship of the regional collaboration pattern,and the attraction network structure in the four diff

关键词： attraction network travel mobility polycentric structure network motif connectivity mechanism destination management organization(DMO) destination planning Beijing,China

同方期刊数据库

An h-adaptive Discontinuous Galerkin Method for laminar Compressible Navier-Stokes Equations on Curved Mesh

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2016年第5期33卷 566-575页

作者： Sun Qiang l yu hongqiang Wu Yizhao College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 P.R. China

An h-adaptive method is developed for high-order discontinuous Galerkin methods(DGM)to solve the laminar compressible Navier-Stokes(N-S)equations on unstructured *** vorticity is regarded as the indicator of *** elements where the vorticity is larger than a pre-defined upper limit are refined,and those where the vorticity is smaller than a pre-defined lower limit are coarsened if they have been refined.A high-order geometric approximation of curved boundaries is adopted to ensure the *** results indicate that highly accurate numerical results can be obtained with the adaptive method at relatively low expense.

关键词： h-adaptivity high-order discontinuous Galerkin methods(DGM) N-S equations high-order boundary approximation

Comparative evaluation of SPE methods for biotoxicity assessment of water and wastewater:linkage between chemical extracting efficiency and biotoxicity outcome

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第8期142卷 33-42页

作者： Jiawei Zhou Shihao Wang Xiwei He hongqiang Ren Xu-Xiang Zhang State Key laboratory of Pollution Control and Resource Reuse School of EnvironmentNanjing UniversityNanjing 210023China

Biotoxicity assessment results of environmental waters largely depend on the sample extraction protocols that enrich pollutants to meet the effect-trigger thresholds of ***,more chemical mixture does not necessarily translate to higher combined ***,there is a need to establish the link between chemical extracting efficiency and biotoxicity outcome to standardize extraction methods for biotoxicity assessment of environmental *** study compares the performance of five different extraction phases in solid phase extraction(SPE),namely HlB,HlB+Coconut,C18 cartridge,C18 disk and Strata-X,and evaluated their chemical extracting efficiencies and biotoxicity *** quantitatively assessed cytotoxicity,acute toxicity,genotoxicity,estrogenic activity,and neurotoxicity of the extracts using in vitro bioassays and characterized the chemical extracting efficiencies of the SPE methods through chemical recoveries of 23 model compounds with different polarities and total organic *** Pareto ranking,we identified HlB+Coconut as the optimal SPE method,which exhibited the highest level of water sample biotoxicity and recovered the most chemicals in water *** found that the biotoxicity outcomes of the extracted water samples significantly and positively correlated with the chemical extracting efficiencies of the SPE ***,we observed synchronous changing patterns in biotoxicity outcome and chemical extracting efficiencies in response to increasing sample volumes per cartridge(SVPC)during *** findings underscore that higher chemical extracting efficiency of SPE corresponds to higher biotoxicity outcome of environmental water samples,providing a scientific basis for standardization of SPE methods for adequate assessment of biotoxicities of environmental waters.

关键词： Biotoxicity Chemical recovery Solid phase extraction Surface water Wastewater

High-Order Discontinuous Galerkin Method for Hovering Rotor Simulations Based on a Rotating Reference Frame

在线全文

学校读者我要写书评

暂无评论

Transactions of Nanjing University of Aeronautics and Astronautics 2019年第1期36卷 57-70页

作者： ZHANG Tao lü hongqiang QIN Wanglong CHEN Zhengwu Department of Aerodynamics Nanjing University of Aeronautics and Astronautics China Aerodynamics Research and Development Center

An implicit higher ? order discontinuous Galerkin(DG) spatial discretization for the compressible Euler equations in a rotating frame of reference is presented and applied to a rotor in hover using hexahedral grids. Instead of auxiliary methods like grid adaptation,higher ? order simulations(fourth ? and fifth ? order accuracy) are *** numerical experiments are carefully designed,conducted and analyzed. The results show generally excellent consistence with references and vigorously demonstrate the higher?order DG method's better performance in loading distribution computations and tip vortex capturing, with much fewer degrees of freedom(DoF). Detailed investigations on the outer boundary conditions for hovering rotors are presented as well. A simple but effective speed smooth procedure is developed specially for the DG method. Further results reveal that the rarely used pressure restriction for outlet speed has a considerable advantage over the extensively adopted vertical speed restriction.

关键词： high-order method(HOM) discontinuous Glaerkin method(DGM) Euler equation hovering rotor simulation tip vortex

Three-dimensionally ordered macroporous(3DOM) structure promoted the activity and H_(2)O poisoning resistance of Ce Mn/3DOM-TiO_(2) catalyst in NH_(3)-SCR

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第3期42卷 523-533,I0004页

作者： Yaqin Hu Shipeng Ding Chenchen Tan Peng Wu Guobo li Sheng Wang hongqiang Yang Yaping Zhang Key laboratory of Energy Thermal Conversion and Control of Ministry of Education School of Energy and EnvironmentSoutheast UniversityNanjing210096China State Power Environmental Protection Research Institute Nanjing210031China

NH_(3)-SCR is an effective mean of NOxremoval in the non-electric industry, however, the high activation temperature and poor H_(2)O resistance of SCR catalysts posed a barrier to its application. In this work, a series of three-dimensionally ordered macroporous(3DOM) catalysts were synthesized via a colloidal crystal template(CCT) method, and various characterizations were carried out to explore the physicochemical property of catalysts. The experiment results reveal that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst presents the excellent low-temperature catalytic activity of nearly 100% at 100℃. Furthermore, the enhanced H_(2)O resistance is achieved, certified by the unaffected NO remove at 150℃ in the participation of 15 vol% H_(2)O. The characterizations results exhibit that the improved dispersion of the active component and enhanced redox ability are conducive to the low-temperature catalytic activity. N_(2) adsorption and desorption experiments indicate that catalyst with 3DOM support possesses a larger pore diameter and specific surface area, which may weaken the condensation of H_(2)O in the microporosity of catalysts and improved the H_(2)O resistance of the catalyst. In situ DRIFTS results manifest that Ce_(0.2)Mn_(0.2)/3DOM-TiO_(2) catalyst could not only absorb more NH_(3) and generate more surface-active sites, but inhibit the competitive adsorption between H_(2)O and SCR reactants.

关键词： 3DOM material NH_(3)-SCR H_(2)O resistance low-temperature Cerium Rare earths

learning Discriminatory Information for Object Detection on Urine Sediment Image

在线全文

学校读者我要写书评

暂无评论

工程与科学中的计算机建模(英文) 2024年第1期138卷 411-428页

作者： Sixian Chan Binghui Wu Guodao Zhang Yuan Yao hongqiang Wang College of Computer Science and Technology Zhejiang University of TechnologyHangzhou310023China The Hefei Institutes of Physical Science Chinese Academy of SciencesHefei230071China Department of Digital Media Technology Hangzhou Dianzi UniversityHangzhou310018China School of Computer Science University of Nottingham Ningbo ChinaNingbo315100China

In clinical practice,the microscopic examination of urine sediment is considered an important in vitro examination with many broad *** the amount of each type of urine sediment allows for screening,diagnosis and evaluation of kidney and urinary tract disease,providing insight into the specific type and ***,manual urine sediment examination is labor-intensive,time-consuming,and *** machine learning based object detection methods require hand-crafted features for localization and classification,which have poor generalization capabilities and are difficult to quickly and accurately detect the number of urine *** learning based object detection methods have the potential to address the challenges mentioned above,but these methods require access to large urine sediment image ***,only a limited number of publicly available urine sediment datasets are currently *** alleviate the lack of urine sediment datasets in medical image analysis,we propose a new dataset named UriSed2K,which contains 2465 high-quality images annotated with expert *** main challenges are associated with our dataset:a large number of small objects and the occlusion between these small *** manuscript focuses on applying deep learning object detection methods to the urine sediment dataset and addressing the challenges presented by this ***,our goal is to improve the accuracy and efficiency of the detection algorithm and,in doing so,provide medical professionals with an automatic detector that saves time and *** propose an improved lightweight one-stage object detection algorithm called *** proposed algorithm comprises a local context attention module and a global background suppression module,which aid the detector in distinguishing urine sediment features in the *** local context attention module captures context information beyond the object region,

关键词： Object detection attention mechanism medical image urine sediment

Modularized and Parametric Modeling Technology for Finite Element Simulations of Underground Engineering under Complicated Geological Conditions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 621-645页

作者： Jiaqi Wu li Zhuo Jianliang Pei Yao li hongqiang Xie Jiaming Wu Huaizhong liu State Key laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China Research Institute of Testing and Inspection Sinohydro Bureau 7 Co.Ltd.Chengdu610213China

The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical *** improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python *** basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FlAC3D software to model and run simulations in the cloud server,and return the simulation results to the web *** modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling *** main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric *** particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling *** and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower *** complicatedmodel is rapidly generated for the simulation,and the simulation results are ***,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.

关键词： Underground engineering modularized and parametric modeling finite element method complex geological structure cloud modeling

Molecular-scale co-assembly membranes derived from keplerate cluster: carbonic anhydrase-mimicking nanocapsules for enhanced CO2/N2 separation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第10期67卷 3271-3282页

作者： Wan-lei Zhao hongqiang li Ruoxuan Zheng Yixin Yang Wei Chen Yu-Fei Song State Key laboratory of Chemical Resource Engineering Beijing University of Chemical Technology Quzhou Institute for Innovation in Resource Chemical Engineering

The development of CO2separation membranes with high permeability and high selectivity,as well as ultra-thin selective layers,has always been ***,a molecular-scaled co-assembly strategy is employed to fabricate the Pebax-Mo132(Pebax=polyether-block-amide copolymer;Mo132=（NH4）42[Mo72ⅥMoⅤ60O372（CH3COO）30（H2O）72]) *** optimal selfstanding membrane,Pebax-Mo132-5%,shows a CO2permeability of～384 Barrer and an ultra-high ideal CO2/N2selectivity of～244,outperforming most membranes reported in the *** CO2permeability and ideal CO2/N2selectivity are increased by 70%and 367%,respectively,compared with the pristine Pebax membrane.A thin-film composite membrane prepared by spin-coating technique on a support membrane with gutter layers also exhibits a CO2permeance of 838 GPU and a CO2/N2selectivity of *** excellent performance can be attributed to the following reasons:（1） strong hydrogen bonding interactions between{Mo132}clusters and Pebax confer excellent interfacial compatibility to the mixed matrix membranes;（2）incorporation of hollow{Mo132}clusters into the Pebax molecular chain decreases the crystallinity of Pebax,and thereby accelerates the chain dynamics and increases the free volume of the membrane;（3） in situ diffuse reflectance infrared Fouriertransform spectroscopy demonstrates that the{Mo132}clusters can effectively catalyze the hydration reaction of CO2and promote the transport of CO2;（4） furthermore,the 0.35 nm pores of the crown ether-type{Mo9O9}allow the accurate size sieving of CO2（0.33 nm） and N2（0.36 nm） molecules.

关键词： polyoxometalates molecular-scale assembly CO2 capture mixed matrix membranes

Path analysis of desirable traits and evaluation of reproductive performance of Crassostrea sikamea in different ages

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Aquaculture and Fisheries 2024年第2期9卷 164-171页

作者： Guangqiu Chang Sheng liu hongqiang Xu Minhai liu Zhihua lin Qinggang Xue National Demonstration Center for Experimental Fisheries Science Education Shanghai Ocean UniversityShanghai201306China Ninghai Institute of Mariculture Breeding and Seed Industry Zhejiang Wanli UniversityNinghaiZhejiang Province315604China Key laboratory of Aquatic Germplasm Resources of Zhejiang Zhejiang Wanli UniversityNingbo315100China

Kumamoto oysters(Crassostrea sikamea)are important marine aquaculture shellfish because of their taste and round shell *** to its small size,selective breeding is required to improve its market size,but there are no reports on traits suitable for direction selection and reproductive productivity of Kumamoto oysters of different *** this study,path analysis and one-way ANOVA were used to explore the influential indices of oyster body weight and *** results showed that shell height was the main factor affecting the body weight of Kumamoto oysters at one-year-old and two-year-old,followed by shell *** weight was the main factor influencing fecundity,and shell height showed a significant correlation with ***,shell height should be considered the first parameter for selection when selecting Kumamoto oysters for body weight as the direct selection *** one-year-old and two-year-old Kumamoto oysters were selected as parents from Xiangshan Bay,hatching parameters and growth parameters of F1 generation larvae were *** fecundity and egg diameters were 1.72×10^(6)and 46.60±3.62μm,respectively,which were significantly greater than one-aged oysters(5.86×10^(5),40.26±3.52μm).The hatching parameters(fertilized egg size,fertilization rate,and hatching rate)and larval growth performance(D-stage veliger and veliger)were similar and did not differ significantly(P>0.05),and after metamorphosis,there was also no significant difference in shell height size at 40 days of age(P>0.05).Therefore,there was no significant effect of age on reproduction,larval development,and the early growth of Kumamoto *** results could provide a basis for parental sources and proper traits for Kumamoto oyster selection,which is beneficial to developing and utilizing this excellent germplasm resource.

关键词： Crassostrea sikamea Path analysis Reproductive performance Growth traits