检索结果-南通市图书馆

Interpretable Machine Learning Method for Compressive Strength Prediction and Analysis of Pure Fly Ash-based Geopolymer Concrete

引用

Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 65-78页

作者： SHI Yuqiong LI Jingyi ZHANG Yang LI Li key laboratory of Agricultural Soil and water Engineering in Arid and Semiarid Areas of Ministry of Education Northwest A&F Uni-versityYangling 712100China College of water Resources and Architectural Engineering Northwest A&F UniversityYangling 712100China Chongqing key laboratory of Public Big Data security Technology Chongqing 401420China Chongqing College of Mobile Communication Chongqing 401520China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina National Rail Transit Electrification and Automation Engineering Technology Research Center(Hong Kong Branch) The Hong Kong Polytechnic UniversityKowloonHung HomHong KongChina

In order to study the characteristics of pure fly ash-based geopolymer concrete(PFGC)conveniently,we used a machine learning method that can quantify the perception of characteristics to predict its compressive *** this study,505 groups of data were collected,and a new database of compressive strength of PFGC was *** order to establish an accurate prediction model of compressive strength,five different types of machine learning networks were used for comparative *** five machine learning models all showed good compressive strength prediction performance on *** them,R2,MSE,RMSE and MAE of decision tree model(DT)are 0.99,1.58,1.25,and 0.25,*** R2,MSE,RMSE and MAE of random forest model(RF)are 0.97,5.17,2.27 and 1.38,*** two models have high prediction accuracy and outstanding generalization *** order to enhance the interpretability of model decision-making,we used importance ranking to obtain the perception of machine learning model to 13 *** 13 variables include chemical composition of fly ash(SiO_(2)/Al_(2)O_(3),Si/Al),the ratio of alkaline liquid to the binder,curing temperature,curing durations inside oven,fly ash dosage,fine aggregate dosage,coarse aggregate dosage,extra water dosage and sodium hydroxide *** temperature,specimen ages and curing durations inside oven have the greatest influence on the prediction results,indicating that curing conditions have more prominent influence on the compressive strength of PFGC than ordinary Portland cement *** importance of curing conditions of PFGC even exceeds that of the concrete mix proportion,due to the low reactivity of pure fly ash.

关键词： machine learning pure fly ash geopolymer compressive strength feature perception

来源：

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

Discrete Numerical Study on Type II Fracture of Partially Detached Concrete Panels in Cold Region

引用

Structural Durability & Health Monitoring 2025年第1期19卷 167-191页

作者： Huayi Zhang Maobin Song Lei Shen Nizar Faisal Alkayem Maosen Cao College of water Conservancy and Hydropower Engineering Hohai UniversityNanjing210024China Haihe River Huaihe River and Xiaoqinghe River Basin Water Conservancy Management and Service Center of Shandong ProvinceJinan250100China College of Mechanics and Engineering Science Hohai UniversityNanjing211100China

When the upper chord beam of the beam-string structure(BSS)is made of concrete-ﬁlled steel tube(CFST),its overall stiffness will change greatly with the construction of concrete placement,which will have an impact on the design of the tensioning plans and selection of control measures for the *** order to accurately obtain the bending stiffness of CFST beam and clarify its impact on the mechanical properties of composite BSS during con-struction,the inﬂuence of some factors such as height-width ratio,wall thickness of steel tube,elasticity modulus of concrete,and friction coefﬁcient on the bending stiffness are analyzed parametrically by the numerical simula-tion technology based on an actual *** calculation formula of the equivalent bending stiffness of CFST is also established through mathematical statistical ***,the equivalent bending stiffness is introduced into the construction and use stages of the composite BSS,respectively,and the mechanical properties such as prestress-tensioning control value,structural deformation,and internal force of key members are comparatively analyzed when adopting two different construction ***,the optimal construction plan of concrete placementﬁrst and then prestress-tensioning is proposed.

关键词： Beam-string structure(BSS) concrete-ﬁlled steel tube(CFST) bending stiffness timing of concrete placement prestress-tensioning

来源：

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

Wetland and habitat dynamics in the evolving landscape of the Middle Yangtze River basin

引用

Journal of Geographical Sciences 2025年第1期 88-111页

作者： YANG Peng SUN Kaiya ZHU Yanchao XIA Jun HUANG Heqing SONG Jingxia SHI Xiaorui LU Xixi hubei key laboratory of Regional Ecology and Environmental Change School of Geography and Information Engineering China University of Geosciences Department of Geography National University of Singapore State key laboratory of water Resources and Hydropower Engineering Science Wuhan University

Wetlands play a critical role in the global environment. The Middle Yangtze River basin(MYRB), known for its abundant wetland resources, has experienced notable changes resulting from the complex interplay of environmental factors. Therefore, we investigated the spatiotemporal characteristics of wetland ecological quality in the MYRB from 2001 to *** the random forest(RF) regression algorithm and patch-generated land-use simulation(PLUS) model, we forecasted variations in wetland habitat quality and their determinants under the Shared Socioeconomic Pathway-Representative Concentration Pathway(SSPRCP) framework from 2035 to 2095. The main findings are as follows:(1) The RF algorithm was optimal for land-use and land-cover(LULC) classification in the MYRB from 2001 to 2020,when notable changes were observed in water bodies and buildings. However, the forested area exhibited an increase and decrease of 3.9% and 1.2% under the SSP1-2.6 and SSP5-8.5 scenarios, respectively, whereas farmland exhibited a diminishing trend.(2) Wetlands were primarily concentrated in the central and eastern MYRB, with counties in the southwest exhibiting superior ecological-environmental quality from 2001 to 2020. Notably,wetland coverage revealed significantly high level, significant changes, frequent but relatively minor changes under the SSP1-2.6, SSP2-4.5, and SSP 5-8.5 scenarios, respectively.(3)Regions with lower habitat quality were primarily concentrated in urbanized areas characterized by frequent human activities, indicating a clear degradation in habitat quality across different scenarios. In conclusion, we established a foundational framework for future investigations into the eco-hydrological processes and ecosystem quality of watersheds.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Safe operation of inverted siphon during ice period

引用

Journal of Hydrodynamics 2015年第2期27卷 204-209页

作者：付辉杨开林郭新蕾郭永鑫王涛 State key laboratory of Simulation and Regulation of water Cycle in River basin China Institute of Water Resources and Hydropower Research

Sixteen inverted siphons are in operation at the Beijing-Shijiazhuang section in the Middle Route of the South-to-North water Diversion Project. Their safe operation is closely related to the safety and the water diversion efficiency of the whole project during an ice period. The ice accumulation process at the inlet of the inverted siphon is modeled under a real ice condition, and then the hydraulic conditions of the ice jam prevention are confirmed. According to the experimental results and the design sizes of the inverted siphons, the detailed safe water diversion discharge and the operational water level are studied. Analysis results of these inverted siphons provide references for the safe operation and the reasonable regulations during the ice period.

关键词： inverted siphon ice period safe operation real ice experiment water diversion project

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Simulation and analysis of ice processes in an artificial open channel

引用

Journal of Hydrodynamics 2013年第4期25卷 542-549页

作者：郭新蕾杨开林付辉王涛郭永鑫 State key laboratory of Simulation and Regulation of water Cycle in River basin China Institute of Water Resources and Hydropower Research

The Middle Route Project for South-to-North water Transfer, which consists of a long artificial open channel and various hydraulic constructions, is a big water conveyance system. A numerical modeling of water conveyance in the ice period for such large-scale and long distance water transfer project is developed based on the integration of a river ice model and an unsteady flow model with complex inner boundaries. A simplified method to obtain the same flow discharge in the upstream and downstream of the structure by neglecting the storage effect is proposed for dealing with the inner boundaries. According to the measured and design data in winter-spring period, the whole ice process, which includes the formation of the ice cover, its development, the melting and the breaking up as well as the ice-water dynamic response during the gate operation for the middle route, is simulated. The ice chara- cteristics and the water conveyance capacity are both analyzed and thus the hydraulic control conditions for a safety regulation are obtained. At last, the uncertainties of some parameters related to the ice model are discussed.

关键词： ice process simulation open channel middle route

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Copula-Based Bivariate Flood Frequency Analysis in a Changing Climate——A Case Study in the Huai River basin, China

引用

Journal of Earth Science 2016年第1期27卷 37-46页

作者： Kai Duan Yadong Mei Liping Zhang State key laboratory of water Resources and Hydropower Engineering Science Wuhan University hubei Provincial Collaborative Innovation Center for water Resources security Wuhan University

Copula-based bivariate frequency analysis can be used to investigate the changes in flood characteristics in the Huai River basin that could be caused by climate change. The univariate distributions of historical flood peak, maximum 3-day and 7-day volumes in 1961-2000 and future values in 2061-2100 projected from two GCMs（CSIRO-MK3.5 and CCCma-CGCM3.1） under A2, A1 B and B1 emission scenarios are analyzed and compared. Then, bivariate distributions of peaks and volumes are constructed based on the copula method and possible changes in joint return periods are characterized. Results indicate that the Clayton copula is more appropriate for historical and CCCma-CGCM3.1 simulating flood variables, while that of Frank and Gumbel are better fitted to CSIRO-MK3.5 simulations. The variations of univariate and bivariate return periods reveal that flood characteristics may be more sensitive to different GCMs than different emission scenarios. Between the two GCMs, CSIRO-MK3.5 evidently predicts much more severe flood conditions in future, especially under B1 scenario, whereas CCCma-CGCM3.1 generally suggests contrary changing signals. This study corroborates that copulas can serve as a viable and flexible tool to connect univariate marginal distributions of flood variables and quantify the associated risks, which may provide useful information for risk-based flood control.

关键词： flood climate change copulas bivariate distribution.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Shrinking of Dongting Lake and its weakening connection with the Yangtze River:Analysis of the impact on flooding

引用

International Journal of Sediment Research 2015年第3期30卷 256-262页

作者： Chunhong Hu Chunming Fang Wenhong Cao State key laboratory of Simulation and Regulation of water Cycle in River basin

In this article,the shrinking of Dongting Lake and its progressively weakening connection with the Yangtze River and their impact on flooding before and after the implementation of the Three Gorges Project are *** recent decades,human activity combined with natural processes has altered the flow of the middle reach channel of the Yangtze River and interfered with its connection with Dongting *** has resulted in progressively more frequent flooding in the *** study uses hydrological data to analyze the annual maximum discharge and annual maximum stage development of the middle reach of the Yangtze River and Dongting *** recent decades before the Three Gorges Project became operational in 2003,the annual maximum discharge and the maximum stage recorded in the middle reach of the river downstream of Dongting Lake had increased,a result of the weakening of the flood regulation function of Dongting Lake;the annual maximum stage at Luoshan station(downstream,close to the confluence of the Yangtze River and Dongting Lake) had risen by about 2.0 m during 1955-2005,(1.5 m attributed to annual maximum discharge and 0.5 m to river channel deposition).Observational data recorded after the Three Gorges Project was put into operation in 2003,it can be seen that deposition in the Dongting Lake has nearly ceased and the lake's connection with the Yangtze River is *** is evident that the flood regulation function of Dongting Lake will continue,and that during the lifetime of the Three Gorges Project,the flood situation in the middle reach of the Yangtze River and Dongting Lake will remain stable.

关键词： Dongting Lake Yangtze River The Three Gorges Project Flood situation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Construction and application of the Synechocystis ***6803-ftnA in microbial contamination control in a coupled cultivation and wastewater treatment

引用

Journal of Environmental Sciences 2016年第8期28卷 174-181页

作者： Yalei Zhang Chunmin Zhang Xuefei Zhou Zheng Shen Fangchao Zhao Jianfu Zhao State key laboratory of Pollution Control and Resource Reuse Key Laboratory of Yangtze Water Environment of Ministry of EducationTongji University water Conservancy Development Research Center Taihu Basin Authority of Ministry of Water Resources

Inspired by iron fertilization experiments in HNLC（high-nitrate, low-chlorophyll） sea areas,we proposed the use of iron-rich engineered microalgae for microbial contaminant control in iron-free culture media. Based on the genome sequence and natural transformation system of Synechocystis sp. PCC6803, ftn A（encoding ferritin） was selected as our target gene and was cloned into wild-type Synechocystis sp. PCC6803. Tests at the molecular level confirmed the successful construction of the engineered Synechocystis sp. PCC6803-ftn A. After Fe3＋-EDTA pulsing, the intracellular iron content of Synechocystis sp. PCC6803-ftn A was significantly enhanced, and the algae was used in the microbial contamination control system. In the coupled Synechocystis sp. PCC6803-ftn A production and municipal wastewater（MW, including Scenedesmus obliquus and Bacillus） treatment, Synechocystis sp. PCC6803-ftn A accounted for all of the microbial activity and significantly increased from 70% of the microbial community to 95%.These results revealed that while the stored iron in the Synechocystis sp. PCC6803-ftn A cells was used for growth and reproduction of this microalga in the MW, the growth of other microbes was inhibited because of the iron limitation, and these results provide a new method for microbial contamination control during a coupling process.

关键词： Synechocystis PCC6803-ftnA Municipal wastewater treatment Microbial contaminants

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Exploring impact of street layout on urban flood risk of people and vehicles under extreme rainfall based on numerical experiments

引用

Science China(Technological Sciences) 2023年第9期66卷 2561-2574页

作者： MEI Chao LIU JiaHong SHI HongYuan WANG Hao WANG Jia DONG LiRong SONG TianXu ZHANG HaiJia State key laboratory of Simulation and Regulation of water Cycle in River basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China key laboratory of River basin Digital Twinning of Ministry of water Resources(Preparation) Beijing 100038China Beijing key laboratory of Urban water Cycle and Sponge City Technology Beijing Normal UniversityBeijing 100875China

Urban street layout is an important factor in the formation process, characteristics, and risk level of urban flooding;therefore, this study numerically investigates the impact of street layout on urban flood risk to people and vehicles. Four typical street-layout scenarios with areas of 3 km × 3 km are established based on a block-scale investigation. The layout types are regular grid,irregular grid, radial, and annular. Urban inundation models are then constructed for these typical street layouts based on the twodimensional(2D) hydrodynamic method. Two historic, extreme rainfall events, which occurred in Beijing on July 21, 2012 and in Zhengzhou on July 20, 2021, are used as rainstorm scenarios for urban inundation modelling. The flood risks to people and vehicles are then calculated. Results show that, for an extreme rainstorm on the block scale, the street layout impacts the spatial and temporal distributions of the inundation variables, which include the water depth, flow velocity, flood volume, and inundated area. Moreover, for the same extreme-rainfall scenario, the greatest differences in the total flood volume, maximum street-water depth, and maximum street-flow velocity caused by street-layout differences are 17.22%, 60.25%, and 61.50%, *** the four street layouts considered in this study, the annular street layout exhibits the lowest degrees of inundation and flood risk. For the same extreme-rainfall scenario, the proportions of high-risk road sections for adults and children in this layout are 58.89% and 62.28% smaller than those for the layout with the largest proportion of high-risk road sections, respectively;the proportions of high-risk road sections for the Honda Accord and Audi Q7 were 55.31% and 53.04% smaller, respectively. The findings of this study may aid scientific understanding and development of “flood-sensitive” block-scale street layouts and urban planning in the context of the changing environment.

关键词： urban inundation street layout urban form flood risk hydrodynamic simulation

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Analysis of load and adaptability of disc cutters during shield tunneling in soft-hard varied strata

引用

Frontiers of Structural and Civil Engineering 2023年第4期17卷 533-545页

作者： Fengwei YANG Weilin SU Yi YANG Zhiguo CAO Yellow River Engineering Consulting Co. Ltd.Zhengzhou 450003China key laboratory of water Management and water security for Yellow River basin Ministry of Water ResourcesZhengzhou 450003China key laboratory of Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

The disc cutters of shield machines exhibit unsatisfactory adaptability and performance during the soft–hard varied strata tunneling *** analyze the rotation state,cutting performance,and adaptability of disc cutters during shield tunneling in soft–hard varied strata,the Holmquist Johnson Cook and Federal Highway Administration constitutive models are introduced to numerically simulate the failure process of materials on the excavation face and to calculate the load of disc ***,the parameters of the models are modified based on laboratory disc cutter excavation test *** results of numerical calculation can reflect the load level and the behavior of the disc cutters during *** tangential loads of the disc cutters during the cutting of four typical soft-strata excavation face models are numerically calculated,thus providing reference values for the starting torque of the disc cutters.A greater penetration is suggested for soft-strata tunneling to allow the disc cutters to rotate smoothly and continuously as well as to guarantee a better cutting *** disc cutters in the center of the cutterhead should be specified with a lower starting torque to prevent uneven wear,rotation stagnation,cutterhead clogging,and other adverse phenomena.

关键词： shield tunneling disc cutter load laboratory excavation test numerical calculation soft-hard varied strata

来源：

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

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：