检索结果-南通市图书馆

A comparison between artificial neural network algorithms and empirical equations applied to submerged weir scour evolution prediction

引用

International Journal of Sediment Research 2023年第1期38卷 105-114页

作者： dawei guan Jingang Liu Yee-Meng Chiew Jian-Hao Hong Liang Cheng Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai University School of Civil and Environment Engineering Nanyang Technological University Sustainability Center Nanhua University School of the Environment and Safety Engineering Jiangsu University

Estimating the time evolution of a local scour hole downstream of submerged weirs can help determine the maximum scour depth and length and is essential to designing submerged weir *** the current study, artificial neural networks with a backpropagation learning algorithm were used to estimate the temporal variation of scour profiles downstream of submerged weirs under clear water conditions. Physical factors, such as the flow condition, weir size, and sediment characteristics, are general scour considerations. Two sets of data combinations, namely original and non-dimensional data, were utilized in developing the backpropagation network(BPN) model. Using the data combinations and a trial-and-error method, the appropriate number of hidden neurons in the model architecture was determined. The results indicated that using non-dimensional variables as inputs in estimating the time evolution of scour holes downstream of a submerged weir is more suitable for the BPN model. Comparisons of the prediction results of the BPN model and an empirical regression formula revealed that the BPN model was more accurate and more direct in predicting the temporal variation of the local scour hole profile. In addition, sensitivity analysis showed that the dimensionless time exerted the most significant impact on the time evolution of the non-dimensional scour hole profile.

关键词： Submerged weir Scour profile Artificial neural networks (ANNs) Time evolution Backpropagation

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

Characterization of horseshoe vortex in a developing scour hole at a cylindrical bridge pier

引用

International Journal of Sediment Research 2019年第2期34卷 118-124页

作者： dawei guan Yee-Meng Chiew Maoxing Wei Shih-Chun Hsieh College of Harbour Coastal and Offshore EngineeringHohai University School of Civil and Environmental Engineering Nanyang Technological University

Since local scour at bridge piers in rivers and estuaries is a major cause of bridge failure,estimation of the maximum local scour depth is of great importance to hydraulic and coastal *** numerous studies that focus on scour-depth prediction have been done and published,understanding of the flow and turbulence characteristics of the horseshoe vortex that drives the scour mechanism in a developing scour hole still is *** study aims to quantify the detailed turbulent flow field in a developing clear-water scour hole at a circular pier using Particle Image Velocimetry(PIV).The distributions of velocity fields,turbulence intensities,and Reynolds shear stresses of the horseshoe vortex that form in front of the pier at different scour stages(t = 0,0.5,1,12,24,and 48 h)are presented in this *** scour development,the horseshoe vortex system was found to evolve from one initially small vortex to three *** strength and size of the main vortex are found to increase with increasing scour *** regions of both the maximum turbulence intensity and Reynolds shear stress are found to form at a location upstream of the main vortex,where the large turbulent eddies have the highest possibility of *** from this study not only provide new insight into the complex flow-sediment interaction at bridge piers,but also provide valuable experimental databases for advanced numerical simulations.

关键词： Sediment transport Scour Bridge pier PIV Horseshoe vortex Turbulence Scour hole

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

Characterization of sand convective motions at a vertical wall subjected to long-term cyclic loading

引用

Fundamental Research 2024年第2期4卷 334-343页

作者： dawei guan Jialong Li Yee-Meng Chiew Jisheng Zhang Key Laboratory of Ministry of Education for Coastal Disaster and Protection Hohai UniversityNanjing 210024China College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210024China Shanghai Investigation Design and Research Institute Co.LtdShanghai 200335China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore

By conducting a two-dimensional experimental study,this paper aims to enhance the understanding of the mechanism of sand convective motions in the vicinity of a wall subjected to long-term cyclic lateral *** experimental tests were conducted in a rectangular sandbox with a transparent front-wall,through which the process of sand particle motions could be recorded by using a high-resolution digital *** images were processed with a high time-resolved PIV(Particle Image Velocimetry)*** on the experimental data,this work(1)presents the sand flow field in the convective zones;(2)provides means to describe the convection mechanism;(3)proposes the relationships between the loading conditions and dimensions of the region with intense sand movement;and(4)elaborates the similarity of the sand flow velocity structure within the sand convective zones.

关键词： Vibration Soil/structure interaction Deformation Particle image velocimetry Laboratory tests

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

Experimental investigation on scour topography around high-rise structure foundations

引用

International Journal of Sediment Research 2021年第3期36卷 348-361页

作者： Yang Xiao Hao Jia dawei guan Dongfang Liang Saiyu Yuan Hongwu Tang State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Yangtze Institute for Conservation and Development Hohai University College of Harbour Coastal and Offshore Engineering Hohai University Department of Engineering University of Cambridge

The current study aims to investigate the characteristics of scour topography around High-Rise Structure Foundations(HRSFs) via physical modeling tests. Clear-water scour tests with a uniform non-cohesive bed are modeled under the action of unidirectional steady flows. Time variations of the erosion and deposition topography are measured. The results show that deposition downstream of the first dune behind the HRSF is not located on the centerline of the wake. The deposition pattern indicates that a long steady wake region exists behind the permeable foundation. The scour depth around an HRSF is much less than that around a monopile because of the structural permeability, which gives rise to the bleed flow and a weakened downflow and horseshoe vortex. Additionally, the asymmetry of the HRSF affects the scour rate but not the final equilibrium scour depth. The average scour slope decreases along the direction of the flow. On the contrary, the scour radial distance increases along the direction of the flow,with the average value changing from 1.36 Deto 2.35 De(where Deis the equivalent diameter of the foundation). Furthermore, the scour hole around the HRSF is serrated rather than smooth owing to the presence of multiple piles. Empirical formulae are suggested for estimating the evolution of scour depth and volume. These laboratory experiments provide reference information for relevant numerical modeling studies and can be applied to guide engineering designs in an ocean area.

关键词： High-rise structure foundation Scour Sediment transport Pile groups

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

Sleep Deprivation Selectively Down-Regulates Astrocytic 5-HT2B Receptors and Triggers Depressive-Like Behaviors via Stimulating P2X7 Receptors in Mice

引用

Neuroscience Bulletin 2020年第11期36卷 1259-1270页

作者： Maosheng Xia Zexiong Li Shuai Li Shanshan Liang Xiaowei Li Beina Chen Manman Zhang Chengyi Dong Alexei Verkhratsky dawei guan Baoman Li Practical Teaching Centre School of Forensic MedicineChina Medical UniversityShenyang 110122China Department of Orthopaedics The First HospitalChina Medical UniversityShenyang 110001China Faculty of Biology Medicine and HealthThe University of ManchesterManchester M139PLUK Department of Forensic Pathology School of Forensic MedicineChina Medical UniversityShenyang 110122China Department of Poison Analysis School of Forensic MedicineChina Medical UniversityShenyang 110122China

Chronic loss of sleep damages health and disturbs the quality of ***-lasting sleep deprivation(SD)as well as sleep abnormalities are substantial risk factors for major depressive disorder,although the underlying mechanisms are not ***,we showed that chronic SD in mice promotes a gradual elevation of extracellular ATP,which activates astroglial P2X7 receptors(P2X7Rs).Activated P2X7Rs,in turn,selectively down-regulated the expression of 5-HT2B receptors(5-HT2BRs)in *** of P2X7Rs induced by SD selectively suppressed the phosphorylation of AKT and FoxO3 a in astrocytes,but not in *** overexpression of FoxO3a in astrocytes inhibited the expression of ***-regulation of 5-HT2BsRs instigated by SD suppressed the activation of STAT3 and relieved the inhibition of Ca2+-dependent phospholipase *** latter cascade promoted the release of arachidonic acid and prostaglandin *** depression-like behaviors induced by SD were alleviated in P2X7R-KO *** study reveals the mechanism underlying chronic SD-induced depression-like behaviors and suggests 5-HT2BRs as a key target for exploring therapeutic strategies aimed at the depression evoked by sleep disorders.

关键词： Astrocyte Sleep deprivation P2X7 receptor 5-HT2B receptor FoxO3a

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

DNA degradation within mouse brain and dental pulp cells 72 hours postmortem

引用

Neural Regeneration Research 2012年第4期7卷 290-294页

作者： Jilong Zheng Xiaona Li Di Shan Han Zhang dawei guan School of Forensic Medicine China Medical University Shenyang 110001 Liaoning Province China School of Forensic Medicine China Criminal Police University Shenyang 110035 Liaoning Province China Department of Chemistry China Medical University School of Basic Medicine Shenyang 110001 Liaoning Province China North Railway Police Station Shenyang Public Security Bureau Shenyang 110013 Liaoning Province China Department of Police Dog Technology China Criminal Police University Shenyang 110035 Liaoning Province China

In this study, we sought to elucidate the process of DNA degradation in brain and dental pulp cells of mice, within postmortem 0-72 hours, by using the single cell gel electrophoresis assay and professional comet image analysis and processing techniques. The frequency of comet-like cells, the percentage of tail DNA, tail length, tail moment, Olive moment and tail area increased in tandem with increasing postmortem interval. In contrast, the head radius, the percentage of head DNA and head area showed a decreasing trend. Linear regression analysis revealed a high correlation between these parameters and the postmortem interval. The findings suggest that the single cell gel electrophoresis assay is a quick and sensitive method to detect DNA degradation in brain and dental pulp cells, providing an objective and accurate new way to estimate postmortem interval.

关键词： DNA degradation single cell gel electrophoresis postmortem interval brain dental pulp

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

Guide to forensic pathology practice for death cases related to coronavirus disease 2019(COVID-19)(Trial draft)

引用

Forensic Sciences Research 2020年第1期5卷 1-7页

作者： Danmi Mao Nan Zhou Da Zheng Jiacheng Yue Qianhao Zhao Bin Luo dawei guan Yiwu Zhou Bingjie Hu Jianding Cheng(Translated) Faculty of Forensic Medicine Zhongshan School of MedicineSun Yat-Sen UniversityGuangzhouChina School of Forensic Medicine China Medical UniversityShenyangChina Department of Forensic Medicine Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina Department of Pathology Guangzhou Medical UniversityGuangzhouChina

Autopsy is of great significance for elucidating the pathological changes,pathogenesis and cause of death of Coronavirus Disease 2019(COVID-19)and can provide a theoretical basis for scientific and accurate prevention and control of its *** on related laws and regulations,such as the Law of the People's Republic of China on Prevention and Control of Infectious Diseases,clinical manifestations and epidemiological characteristics of COVID-19 and guidelines on the prevention and control of this epidemic,combined with the practical work of forensic pathology examinations,we developed the Guide to Forensic Pathology Practice for Death Cases Related to Coronavirus Disease 2019(COVID-19)(Trial Draft).This guide describes the background investigation of the death cases,autopsy room requirements,personal pre-vention and protections,external examinations,autopsy practices and auxiliary examinations,and thus offers a reference for forensic and pathological examination institutions and staff.

关键词： Forensic sciences forensic pathology autopsy SARS-CoV-2 Coronavirus Disease 2019 (COVID-19) guide

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

Sudden cardiac death of Duchenne muscular dystrophy with NT-proBNP in pericardial fluid as a useful biomarker for diagnosis of the cause of death: a case report

引用

Forensic Sciences Research 2020年第2期5卷 165-169页

作者： Mengzhou Zhang Rui Zhao Tianshui Yu Jiaoyong Li Miao Zhang Shukun Jiang Linlin Wang Guohua Zhang Rubo Li Baoli Zhu dawei guan Department of Forensic Pathology China Medical University School of Forensic MedicineShenyangChina Remote Forensic Consultation Center Collaborative Innovation Center of Judicial CivilizationChina University of Political Science and LawBeijingChina

Duchenne muscular dystrophy(DMD)is one of the most common and severest muscular *** it can be a cause of death when associated with cardiac muscle and/or respiratory muscles,no cases of sudden deaths in the setting of undiagnosed DMD with cardiac involvement have been reported in the *** studies showed that N-terminal-proBNP(NT-proBNP)was a robust laboratory biomarker to diagnose and monitor cardiac failure in clinical situations,suggesting that it may be used as an auxiliary indicator for diagnosis on left ventricular dysfunction in sudden cardiac deaths in forensic ***,we reported a case of 29-year-old man who died *** revealed that muscles of the body were almost replaced by fatty and fibrotic *** heart was enlarged with disarray and degeneration of cardiomyocytes in cardiac *** absence of dystrophin was detected by immunohistochemical staining,which confirmed *** biochemical test of pericardial fluid revealed a high level of NT-proBNP,indicating dysfunction of the left ventricle before *** cause of death was certified as an early dilated cardiomyopathy(DCM)/dysfunction of the left ventricle secondary to DMD,suggesting that sudden cardiac death with cardiac dysfunction could be identified by immunohistochemical method in combination with pericardial fluid NT-proBNP determination after systemic autopsy.

关键词： Forensic sciences forensic medicine NT-proBNP sudden cardiac death Duchenne muscular dystrophy left ventricular dysfunction

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

Suncus murinus, a house musk, shrew is a new reservoir of rat HEV

Suncus murinus, a house musk, shrew is a new reservoir of ra...

引用

2015新发传染病防治热点研讨会

作者： dawei guan Wei Li Juan Su Institute of Microbiology Center for Disease Control and Prevention of Guangdong Province

Anti-rat HEV Ig G and Ig M antibodies were detected in 10.4%(27/260) and 4.6%(12/260), respectively, of sera collected from Suncus murinus, a house musk shrew, in which five out of 10 Ig M-positive sera were positive ...

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

产业升级背景下我国经济发展的制度创新

引用

改革与战略 2017年第6期33卷 54-56页

作者：关大卫黄河科技学院河南郑州450063

经济发展离不开制度创新。经济新常态下,我国经济发展制度创新,是产业转型升级的核心动力。经济活动行为准则与生产力相适应的关系,以及制度的规模经济功能,是产业升级的制度需求。产业升级背景下,革新制度创新理念,强化政府职能作用,... 详细信息

经济发展离不开制度创新。经济新常态下,我国经济发展制度创新,是产业转型升级的核心动力。经济活动行为准则与生产力相适应的关系,以及制度的规模经济功能,是产业升级的制度需求。产业升级背景下,革新制度创新理念,强化政府职能作用,打破行政垄断,坚持制度创新,有利于促进我国经济可持续发展。

关键词：产业升级经济发展制度创新

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

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：