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COOPERATIVE CLUSTERING BASED ON GRID AND DENSITY

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Chinese Journal of Mechanical Engineering 2006年第4期19卷 544-547页

作者： hu Ruifei YIN Guofu TAN Ying CAI Peng School of Manufacturing Science and Engineering Sichuan University Chengdu 610065 China

Based on the analysis of features of the grid-based clustering method-clustering in quest （CLIQUE） and density-based clustering method-density-based spatial clustering of applications with noise （DBSCAN）, a new clustering algorithm named cooperative clustering based on grid and density （CLGRID） is presented. The new algorithm adopts an equivalent rule of regional inquiry and density unit identification. The central region of one class is calculated by the grid-based method and the margin region by a density-based method. By clustering in two phases and using only a small number of seed objects in representative units to expand the cluster, the frequency of region query can be decreased, and consequently the cost of time is reduced. The new algorithm retains positive features of both grid-based and density-based methods and avoids the difficulty of parameter searching. It can discover clusters of arbitrary shape with high efficiency and is not sensitive to noise. The application of CLGRID on test data sets demonstrates its validity and higher efficiency, which contrast with tradi- tional DBSCAN with R tree.

关键词： Data mining Clustering Seed object

超大城市洪涝灾害成因综合解析——以重庆市为例

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土木与环境工程学报（中英文） 2025年第1期47卷 1-10页

作者：仉文岗王云浩胡庆芳孙伟鑫金君良重庆大学土木工程学院重庆400045 南京水利科学研究院水文水资源与水利工程科学国家重点实验室南京210029

近年来,极端天气事件呈现趋多趋强态势,变化环境下洪涝灾害频发给社会经济发展带来严峻挑战。重庆是中国西部超大城市和成渝城市群“双核”之一,主城区地貌以山地、丘陵为主,受上游江河来水和三峡库区回水的双重影响,洪涝灾害风险突出... 详细信息

近年来,极端天气事件呈现趋多趋强态势,变化环境下洪涝灾害频发给社会经济发展带来严峻挑战。重庆是中国西部超大城市和成渝城市群“双核”之一,主城区地貌以山地、丘陵为主,受上游江河来水和三峡库区回水的双重影响,洪涝灾害风险突出。以重庆市历年洪涝灾害事件为基础,梳理重庆市防涝减灾现状,分析水文、地理、地形、城市化、气象等因素对重庆市洪涝灾害发生频率和强度的影响,结合这些洪涝灾害致灾因子进一步对重庆市的孕灾环境和承灾体进行分析,提出针对重庆中心城区洪涝治理的对策建议。分析发现:重庆市洪涝灾害受多种因素综合影响,特殊的地理位置和山地城市的地形条件决定了重庆防洪治涝的艰巨性;重庆市河流纵横,山高谷深,完全具备发生洪涝灾害的孕灾条件;应充分考虑气象水文和经济社会发展的新情况,根据三峡水库等建成后的洪涝灾害特征和城区防洪防涝能力现状,及时优化城市洪涝灾害防御体系。

关键词：城市灾害洪涝灾害防灾减灾防洪规划

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Electrodeposition of Copper from Citrate Alkaline Solution Containing Polyethyleneimine(PEI)

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稀有金属材料与工程 2012年第S1期41卷 172-175页

作者： Wen, Zhan Na, Du hu Lixin Ou Yanggui Wuhan Res Inst Mat Protect Wuhan 430030 Peoples R China hubei Univ Technol Wuhan 430068 Peoples R China

Mechanism of citrate alkaline copper electrodeposition in presence of polyethyleneimine was *** by SEM,It's propitious to obtain fine and symmetrical copper film at wider current densities with *** analysis indicated copper deposits exhibited growth orientation of crystal face(111),which remained with parallel *** voltammograms results indicated that polyethyleneimine adsorbing preferentially at cathode high current density area could make a stronger inhibition on copper *** by chronoamperometry,it's showed that initial stage behavior of copper electrodeposition belonged to diffusion controlled and three-dimensional progressive nucleation.

关键词： alkaline copper electrodeposition polyethyleneimine surface morphology growth orientation progressive nucleation

Cramer-Rao lower bound-based observable degree analysis

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Science China(Information Sciences) 2019年第5期62卷 29-31页

作者： Quanbo GE Tianxiang CHEN Hongli HE Zhentao hu School of Automation Hangzhou Dianzi University Chinese Flight Test Establishment College of Computer and Information Engineering Henan University

Dear editor,Controllability and observability are basic concepts in modern control theory that are based on Kalman filtering (KF)[1, 2]. In particular, observability is closely related to state estimation ability [2–4]. The indicator called observable degree(OD) has been used to quantitatively measure the degree of observability [5–7]. However, limited by

关键词： ODA Cramer-Rao lower bound-based observable degree analysis

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文化视角下新疆乌恰县城镇风貌特色塑造研究

山西建筑 2025年第3期51卷 38-42,66页

作者：钱舒皓屠泳博胡金常州市规划设计院江苏常州213003

随着城镇化的快速推进和外来文化的冲击,城镇风貌中体现地域文化的内容越来越少,文化传承的重要性愈发凸显,该文研究了文化元素与城镇风貌塑造的理论框架,以新疆乌恰县旧城更新规划为案例,对其民族文化、自然文化、口岸商贸文化和民居... 详细信息

随着城镇化的快速推进和外来文化的冲击,城镇风貌中体现地域文化的内容越来越少,文化传承的重要性愈发凸显,该文研究了文化元素与城镇风貌塑造的理论框架,以新疆乌恰县旧城更新规划为案例,对其民族文化、自然文化、口岸商贸文化和民居建筑文化进行了分析和挖掘,并提炼出特色的文化基因,最后从总体引导、建筑优化、景观设计、街道主题四个方面提出了基于文化的风貌规划策略,为城镇风貌塑造中的文化传承与利用提供一定参考。

关键词：地域文化城镇风貌少数民族地区城市更新民居建筑

Hole scattering mechanism of strained Si/(111)Si_(1-x)Ge_x

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Science China(Physics,Mechanics & Astronomy) 2011年第10期54卷 1801-1804页

作者： WANG Cheng ZHANG HeMing SONG JianJun hu huiYong Key Lab of Wide Band-Gap Semiconductor Materials and Devices School of Microelectronics Xidian University Xi'an 710071 China

Based on Fermi’s golden rule and the theory of Boltzmann collision term approximation, the hole scattering mechanism ofstrained Si/(111)Si1 xGexwas established, including ionized impurity, acoustic phonon, non-polar optical phonon and totalscattering rate models. It was found that the total scattering rate of the hole in strained Si/(111)Si1 xGexdecreased obviouslywith the increasing stress when energy was 0.04 eV. In comparison with one of the unstrained Si, the total hole scattering rateof strained Si/(111)Si1 xGexdecreased about 38% at most. The decreasing hole scattering rate enhanced the hole mobility instrained Si materials. The result could provide valuable references to the research on hole mobility of strained Si materials andthe design of PMOS devices.

关键词： strained Si scattering rates mobility

Bird guild loss and its determinants on subtropical land-bridge islands, China

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Chinese Birds 2015年第2期6卷 99-106页

作者： Zhifeng Ding Kenneth James Feeley huijian hu Ping Ding The Key Laboratory of Conservation Biology for Endangered Wildlife of the Ministry of Education College of Life Sciences Zhejiang UniversityZijin’gang Campus Guangdong Entomological Institute & South China Institute of Endangered Animals Department of Biological Sciences Florida International University Center for Tropical Plant Conservation Fairchild Tropical Botanic Garden

Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or ***: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), ***: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy ***: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems.

关键词： Bird guilds Island area Land-bridge islands PAR Thousand Island Lake z values

INHIBITION MECHANISM OF Na_2MoO_4 FOR CARBON STEEL IN 55% LiBr SOLUTION

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Chinese Journal of Mechanical Engineering 2007年第4期20卷 15-18页

作者： LIANG Chenghao huANG Naibao GUO Jianwei hu Xianqi Electromechanics and Materials Engineering College Dalian Mantime University Dalian 116026 China School of Chemical Engineering Dalian University of Technology Dalian 116012 China Electromechanics and Materials Engineering College Dalian Maritime University Dalian 116026 Ch na nstitute of Nuclear and New Energy Technology Tsinghua University Beijing 100084 China

Electrochemical measurement and chemical immersion test are employed to investigate the inhibition mechanism of Na2MoO4 for carbon steel,which is studied in 55%LiBr＋0.07mol/L LiOH solution at high *** results indicate that the passive film on carbon steel surface is mainly composed of Fe3O4,and Mo is involved in the process of film forming,in a form of MoO3 and *** parametric analysis of the evolving potential and the blend potential of MoO2 shows that Mo mainly exists as MoO2 in passive film when the concentration of Na2MoO4 is lower than 150 mg/*** its concentration is greater than 150mg/L,it mainly exists as MoO3 inside the film and exists as MoO2 outside the ***4^2- is deoxidized as MoO2 on the surface of carbon steel,which may impede the corrosion of active-site and raise the blend potential of carbon steel,and then MoO4^2- adsorbs onto the defects of the passive film and decompounds as MoO3 during the process of film *** electric field caused by different valence of Mo in passive film may retard the dissolution of carbon steel and lead to an increase in the polarization impedance and a decrease in hydrogen *** a result,heavy concentrated Na2MoO4 solution（greater than 150mg/L）has excellent inhibition effect on carbon steel in LiBr solution.

关键词： LiBr solution Carbon steel Anticorrosion Na2MoO4

Monte Carlo simulation of GEM-based for 14 MeV neutron detector

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Science China(Physics,Mechanics & Astronomy) 2013年第9期56卷 1740-1744页

作者： WANG XiaoDong ZHANG YuLian ZHANG Chunhui hu BiTao School of Nuclear Science and Technology Lanzhou University

A new concept of neutron detector based on Gas Electron Multiplier(GEM) technology is presented in this paper,in which a novel multi-layer high density polyethylene(HDPE) as neutron-to-proton converter is proposed and studied with Geant4 toolkit for fast 14 MeV *** preliminary results show that the detection efficiency of the detector with 400 converter units is higher than 2.3% and reconstruction accuracy of the incident neutron position is higher than 2.6%.

关键词： gas electron multiplier 14 MeV neutron detection efficiency position reconstruction