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Relationships between Modified Methylene Blue Value of Microfines in Manufactured Sand and co.crete Properties

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Journal of Wuhan University of Technology(Materials Science) 2016年第3期31卷 574-581页

作者：刘战鳌周明凯 LI Beixing State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China china three gorges co.struction management co.Ltd. Chengdu 610041China

To better understand and assess the effect of microfines on co.crete properties, the synergetic effect of methylene blue value and co.tent of microfines on properties of low and high strength co.crete was studied and then the relationships between the index of modified methylene blue value （MMBV） and co.crete properties were investigated. The results show that relationships between MMBV and fresh and hardened properties of co.crete can be fully established, and the co.relation between MMBV and C60 co.crete property is higher than the co.relation between MMBV and C30 co.crete. With the increase of MMBV, co.crete workability and frost resistance decrease while drying shrinkage decreases; however, co.pressive strength and chloride-ion penetration resistance of C30 co.crete have not been negatively affected whereas those of C60 co.crete are significantly deteriorated when MMBV exceeds 100. To make use of microfines without remarkably damaging co.crete quality, it is suggested that MMBV of microfines in MS used in C30 and C60 co.crete be no more than 100.

关键词： microfines manufactured sand modified methylene blue low and high strength co.crete

Priority Setting in Health Care with Disease and Treatment Risks

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Journal of Systems Science and Information 2018年第6期9卷 552-562页

作者： Yuqing TAO Wen CHENG Sijie ZOU Department of Teacher Education Maanshan Teacher's College Department of Risk management China Huarong Asset Management Co. Ltd Department of Finance Shandong Branch China Three Gorges New Energy Co. Ltd

This paper deals with the issue of priority setting in health care under uncertainties about the severity of the illness and the effectiveness of medical treatment. We examine the effect of a disease uncertainty(a treatment uncertainty) on the allocation of health care resources in the presence of a treatment risk(a disease risk) and identify preference co.ditions under which the social planner allocates more resources to higher risk population. We allow for the simultaneous presence of two risks and investigate the joint effect of two-source uncertainties on health care allocation when the two risks are either small or positively quadrant dependent. The effect of inequality aversion on health care allocation is also analyzed by introducing an equity weighting function. Our work extends the previous model of health care priority to two-risk framework and provides new insights into the problem of health care decision making under uncertainty.

关键词： priority setting health care management risks co.relation partial relative prudence inequality aversion

Progressive fragmentation of granular assemblies within rockslides: Insights from discrete-co.tinuous numerical modeling

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Journal of Mountain Science 2024年第4期21卷 1174-1189页

作者： JIANG Hui ZHOU Yuande WANG Jinting DU Xiuli HUANG Hailong Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China. Key Laboratory of the Hydrosphere Sciences of the Ministry of Water Resources Tsinghua UniversityBeijing 100084China china three gorges co.struction management co. Ltd.Chengdu 610000China

Rock fragmentation plays a critical role in rock avalanches,yet co.ventional approaches such as classical granular flow models or the bonded particle model have limitations in accurately characterizing the progressive disintegration and kinematics of multi-deformable rock blocks during *** present study proposes a discrete-co.tinuous numerical model,based on a co.esive zone model,to explicitly inco.porate the progressive fragmentation and intricate interparticle interactions inherent in *** rock granular assemblies are released along an inclined plane and flow onto a horizontal *** numerical scenarios are established to inco.porate variations in slope angle,initial height,friction co.fficient,and particle *** evolutions of fragmentation,kinematic,runout and depositional characteristics are quantitatively analyzed and co.pared with experimental and field data.A positive linear relationship between the equivalent friction co.fficient and the apparent friction co.fficient is *** general,the granular mass predominantly exhibits characteristics of a dense granular flow,with the Savage number exhibiting a decreasing trend as the volume of mass *** process of particle breakage gradually occurs in a bottom-up manner,leading to a significant increase in the angular velocities of the rock blocks with increasing *** simulation results reproduce the field observations of inverse grading and source stratigraphy preservation in the *** propose a disintegration index that inco.porates factors such as drop height,rock mass volume,and rock *** findings demonstrate a co.sistent linear relationship between this index and the fragmentation degree in all tested scenarios.

关键词： Rock fragmentation Rockslide Numerical modelling Discrete-co.tinuous modelling Runout co.esive zone model

Role of unsteady tip leakage flow in aco.stic resonance inception of a multistage co.pressor

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Chinese Journal of Aeronautics 2023年第10期36卷 165-181页

作者： Xiaohua LIU Zihao WU Changxin SI Jun YANG Xiaofeng SUN School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory(Fluid Machinery and Engineering Research Base)of Sichuan Province Xihua UniversityChengdu 610039China china three gorges investment management co.Ltd Shanghai 200124China School of Energy and Power Engineering University of Shanghai for Science and TechnologyShanghai 200093China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

In previous studies,a theoretical model was developed after Aco.stic Resonance(AR)was experimentally detected in a four-stage co.pressor,and AR inception was proposed to be triggered by an unknown sound source,which is a pressure perturbation of a specific frequency with a suitable circumferential propagation *** present paper,which is not dedicated to the simulation of aco.stic field,aims to identify the specific sound source generated by the unsteady tip leakage flow using the unsteady co.putational Fluid Mechanics(CFD)*** a co.prehensive analysis of an Unsteady Reynolds Averaged Navier-Stokes(URANS)simulation,a pressure perturbation of non-integer multiple of rotor frequency is found at the blade *** the essence of the tip leakage flow is a jet flow driven by the pressure difference between two sides of blade,a simplified tip leakage flow model is adopted using Large Eddy Simulation(LES)in order to simulate the jet flow through a tip *** is found that the co.vection velocity of shedding vortices fits the expected propagation speed of the sound source,the frequency is also close to one of the dominating frequencies in the URANS simulation,and the resultant co.bination frequency co.ncides with the experimentally measured AR *** such a simplified model successfully captures the key physical mechanisms,it is co.cluded that this paper provides a piece of unambiguous evidence on the role of unsteady tip leakage vortex in triggering the AR inception of the multistage co.pressor.

关键词： Aco.stic Resonance(AR) Jet flow Multistage co.pressor Tip leakage flow Unsteady flow

Spatial Distribution and Risk Assessment of Heavy Metals in Paddy Soils of Yongshuyu Irrigation Area from Songhua River Basin,Northeast china

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Chinese Geographical Science 2018年第5期28卷 797-809页

作者： CUI Zhengwu WANG Yang ZHAO Na YU Rui XU Guanghui YU Yong Northeast Institute of Geography and Agroeco.ogy Chinese Academy of Sciences Changchun 130102 China Jilin Provincal Government investment Fund management co. LTD. Changehun 130000 China

There is an increasing co.cern for potentially hazardous metals pollution, which can threaten crops production and human health. In this study, the spatial distribution and environmental risks of eight heavy metals in surface soil samples co.lected from the paddy fields in Yongshuyu irrigation area, Northeast china were investigated. The mean co.centrations of Pb, Cr, Cu, Ni, Zn, Cd, Hg and As were 34.6 ± 4.67, 82.8 ± 9.51, 17.3 ± 4.09, 21.2 ± 12.0, 88.6 ± 17.9, 0.18 ± 0.15, 0.22 ± 0.07 and 8.77 ± 2.47 mg/kg, respectively, which were slightly higher than their co.responding background values of Jilin Province, indicating enrichment of these metals in the paddy soils, especially for Ni, Cd and Hg. The spatial distribution of heavy metals was closely co.related with local anthropogenic activities, such as agricultural production, mining and transportation. The hot-spot areas of As and Cd were mainly co.centrated in the up-midstream where were associated with agricultural activities. Cr and Cu showed similar spatial distributions with hot-spot areas distributed the whole irrigation area uniformly. Ni was mainly distributed in the downstream where Ni quarries co.centrated, while the spatial distribution patterns of Hg was mainly located in the upstream and downstream where the soil was significantly influenced by irrigation and co.l mining emission. The spatial distributions of Pb and Zn were mainly co.centrated along the highway side. The pollution levels of Yongshuyu irrigation area were estimated through index of geo-accumulation(Igeo), Nemerow integrated pollution index(NIPI) and potential eco.ogical risk index(PERI). The results showed that Cd and Hg were the main pollutants in the study area. Health risk assessment results indicated that children were in higher non-carcinogenic and carcinogenic risks than adults with the carcinogenic metal of As. Ingestion was the main exposure pathway to non-carcinogenic and carcinogenic risk for both adults and children. Princip

关键词： spatial distribution heavy metals paddy soil risk assessment source identification Songhua River Basin

Quantitative evaluation of urban park co.l island factors in mountain city

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Journal of Central South University 2012年第6期19卷 1657-1662页

作者：卢军李春蝶杨永川张歆晖靳鸣 Key Laboratory of The three gorges Reservoir Region's Eco.Environment(Chongqing University) Ministry of Education Sichuan Southwest Project management co.sulting co.Ltd.

Evaluating how park characteristics affect the formation of a park co.l island(PCI) is the premise of guiding green parks planning in mountain *** diurnal variation of PCI intensity was achieved,and co.relations between PCI intensity and park characteristics such as park area,landscape shape index(LSI),green ratio and altitude were analyzed,using 3 010 temperature and humidity data from measurements in six parks with typical park characteristics in Chongqing,*** results indicate that:1) the main factor determining PCI intensity is park area,which leads to obvious co.l island effect when it exceeds 14 hm2;2) there is a negative co.relation between PCI intensity and LSI,showing that the rounder the park shape is,the better the co.l island effect co.ld be achieved;3) regression analysis of humidity and PCI intensity proves that photosynthesis midday depression(PMD) is an important factor causing the low PCI intensity at 13:00;4) the multivariable linear regression model proposed here co.ld effectively well predict the daily PCI intensity in mountain cities.

关键词： park co.l island park characteristics regression analysis photosynthesis midday depression statistical model

Quantifying the impact of earthquakes and geological factors on spatial heterogeneity of debris-flow prone areas:A case study in the Hengduan Mountains

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Journal of Mountain Science 2024年第5期21卷 1522-1533页

作者： HU Xudong SHEN Yitong HU Kaiheng XU Wennian LIU Daxiang HE Songtang GAO Jiazhen WEI Li LIU Shuang Hubei Provincial Engineering Research Center of Slope Habitat co.struction Technique Using Cement-based Materials(china three gorges University) Yichang 443002China Hubei Key Laboratory of Disaster Prevention and Mitigation(china three gorges University) Yichang 443002China co.lege of Civil Engineering and Architecture China Three Gorges UniversityYichang 443002China Shanghai Investigation Design&Research Institute Co.Ltd.Shanghai 200335China Key Laboratory of Mountain Hazards and Earth Surface Processes Chinese Academy of SciencesChengdu 610041China Institute of Mountain Hazards and Environment Chinese Academy of SciencesChengdu 610041China Wuhan Polytechnic Wuhan 430074China

Understanding the spatial heterogeneity of debris-flow-prone areas holds significant implications for regional risk management, particularly in seismically active regions with geological faults. Despite the significance of this knowledge, a co.prehensive quantification of the influence of regional topographical and geological factors on the spatial heterogeneity of debris-flow-prone areas has been lacking. This study selected the Hengduan Mountains, an earthquake-prone region characterized by diverse surface co.ditions and co.plex landforms, as a representative study area. An improved units zoning and objective factors identification methodology was employed in earthquake and fault analysis to assess the impact of seismic activity and geological factors on spatial heterogeneity of debrisflow prone areas. Results showed that the application of GIS technology with hydrodynamic intensity and geographical units analysis can effectively analyze debris-flow prone areas. Meanwhile, earthquake and fault zones obviously increase the density of debrisflow prone catchments and make them unevenly distributed. The number of debris-flow prone areas shows a nonlinear variation with the gradual increase of geomorphic factor value. Specifically, the area with 1000 m-2500 m elevation difference, 25°-30° average slope, and 0.13-0.15 land use index is the most favorable co.ditions for debris-flow occurrence;The average annual rainfall from 600 to 1150 mm and landslides gradient from 16° to 35° are the main causal factors to trigger debris flow. Our study sheds light on the quantification of spatial heterogeneity in debris flow-prone areas in earthquake-prone regions, which can offer crucial support for post-debris flow risk management strategies.

关键词： debris-flow prone areas causal factors GIS-based method spatial heterogeneity Hengduan Mountains

Spatiotemporal variations of co.(2) fluxes in a Cynodon-dominated riparian zone of the three gorges Reservoir(TGR),china

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Journal of Plant Eco.ogy 2018年第6期11卷 877-886页

作者： Wenli Zhang Jiquan Chen Ju Liu Fangqing Chen Quanfa Zhang Zutao Ouyang Changliang Shao Yi Fan Wennian Xu co.lege of Biological and Pharmaceutical Sciences China Three Gorges UniversityYichangHubei 443002China Hubei International Scientific and Technological co.peration Center of Eco.ogical co.servation and management in three gorges Area China Three Gorges UniversityYichang443002China Center for Global Change and Earth Observations/Geography Environment and Spatial SciencesMichigan State UniversityEast LansingMI 48823USA Key Laboratory of Aquatic Botany and Watershed Eco.ogy Wuhan Botanical Gardenthe Chinese Academy of SciencesWuhan 430074China

Aims Riparian eco.ystems play an important role in overall eco.ystem function,including the global carbon cycle of terrestrial eco.ystems,at both landscape and global *** few studies have reported in situ measurements of co.(2) in riparian areas where flooding is a unique disturbance to carbon *** At multiple locations across riparian zones(RZ)with different water submergences in Xiangxi Bay(XXB),we studied seasonal variations of co.(2) exchange between this Cynodon-dominated co.munity and the atmosphere for 2 years by using static *** Findings We found that the seasonal changes in co.(2) fluxes were apparent and dependent on the biophysical *** the beginning of spring,low gross primary productivity(GPP)in lightly flooded zones(LFZ)resulted in a positive net eco.ystem exchange(NEE),indicating a net co.(2) *** the increase in temperature,more species and vegetation abundance appeared,and the increased GPP turned the LFZ from a net co.(2) source into a *** transi-tion seemed predominantly co.trolled by the physiological growth of *** mean NEEs,REs and the light-use efficiency(α)of the vegetation at HFZ and MFZ were significantly higher than those at LFZ and *** the co.fficients of variation(CV)of NEE and RE at MFZ and HFZ were lower than those at LFZ and *** promoted the emission and uptake of co.(2) to the *** submergence reduced the number of spe-cies and lowered the spatial variability of the RZ,further lowering the variation of the co.(2) exchange.

关键词： co.(2)exchange riparian submergence spatial variability Q_(10) TGD

Intelligent Diagnosis Method for Typical co.frequency Vibration Faults of Rotating Machinery Based on SAE and Ensembled ResNet-SVM

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 215-230页

作者： Xiancheng Zhang Xin Pan Hao Zeng Haofu Zhou Beijing Key Laboratoryof Health Monitoring and Self-reco.ery for High-end Mechanical Equipment Beijing University of Chemical TechnologyBeijing 100029China Engineering Research Center of Chemical Safety(Ministry of Education) Beijing University of Chemical TechnologyBeijing 100029China Engineering management Department of china three gorges New Energy(Group)co. Ltd.Beijing 101199China

Intelligent fault diagnosis is an important method in rotating machinery fault diagnosis and equipment health *** deal with co.frequency vibration faults,a type of typical fault in rotating machinery,this paper proposes a fault diagnosis method based on the stacked autoenco.er(SAE)and ensembled ***,the time-and frequency-domain features of several co.frequency vibration faults are summarized based on the mechanism analysis and calculated using actual vibration *** realize and validate the high-precision diagnosis method of rotating equipment with co.frequency faults proposed in this study,the following three criteria are required:First,to improve the effectiveness and robustness of the ensembled model and the sliding window using data augmentation,adding noise,autoenco.er(AE)and SAE methods are analyzed in terms of principle and practical ***,ResNet is used as the feature extractor for the ensembled ResNet-SVM *** extraction is carried out twice,and the extracted co.frequency fault features are more ***,the data augmentation method and ensemble ResNet-SVM are co.bined for fault diagnosis and co.pared with other *** experimental results show that the accuracy of the proposed method can exceed 99.9%.

关键词： co.frequency vribation Data argumentation Ensembeled ResNet-SVM High precision fault diagnosis