检索结果-南通市图书馆

Large eddy simulation of flow in a street canyon with tree planting under various atmospheric instability conditions

引用

Science China(Technological Sciences) 2010年第7期53卷 1928-1937页

作者： GU ZhaoLin1, ZHANG YunWei2 & LEI KangBin3 1 School of Human Settlements and Civil Engineering, Xi’an Jiaotong University, Xi’an 710049, China 1 School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an 710049, China 3 RIKEN Institute, Wako, Saitama, 351-0198, Japan 1. School of Human Settlements and Civil Engineering Xi’an Jiaotong University Xi’an 710049 China2. School of Energy and Power Engineering Xi’an Jiaotong University Xi’an 710049 China3. RIKEN Institute Wako Saitama 351-0198 Japan

In this work, a large eddy simulation (LES) model, which includes momentum and heat source (or sink) inside the tree planting layer, is proposed for the simulation of flow in a street canyon with tree planting. Vegetation canopy layer simulation shows that this model can be used to simulate the velocity distribution and temperature variation inside the canopy layer. Effects of atmospheric instability on flow and pollutant distribution in a street canyon with tree planting of an aspect ratio of 0.5 are studied. Results show that compared with the canyon with no tree planting (or the exposed street canyon), the canyon with tree planting shows a reduced wind circulation and pollutant exchange rate (PER) at the top layer of the street canyon, which induces the increase in the pollutant concentrations near road surface, leeward wall and windward wall. When street canyon atmosphere is under a strongly unstable condition, wind velocity decreases while pollutant concentration is increased in the areas near the street canyon top, road surface, leeward and windward walls, compared with the wind velocity in the street canyon with the neutral stratification. When street canyon atmosphere is under a weakly unstable condition, wind velocity weakens near the street canyon top and windward wall, but strengthens near the road surface and leeward wall, and pollutant concentration is decreased near the leeward and windward walls and is increased between the two rows of trees. When the street canyon atmosphere is under an unstable condition, PER is lower than that under the neutral stratification.

关键词： street canyon flow tree planting atmospheric instability large eddy simulation pollutant concentration 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

Exploring Location Pattern of Commercial Stores in Shichahai, Beijing from a street Centrality Perspective

引用

Chinese Geographical Science 2019年第3期29卷 503-516页

作者： ZHANG Yuyang YANG Bowen ZHANG Mengcai ZHANG Gong SONG Shanshan QI Ling College of Architecture and Civil Engineering Beijing University of Technology School of Urban Planning and Design Peking University Heilongjiang 904 Hydrogeological and Engineering Geology Investigation Institute Research Center for Historic and Cultural Cities of National Importance Beijing Tsinghua Tongheng Urban Planning & Design Institute Beijing University of Chinese Medicine College of Architecture and Urban Planning Beijing University of Technology

The location pattern of different commercial stores in Shichahai, a historic conservation area in Beijing, was investigated from a street centrality perspective. Many previous studies have investigated the relationship between street centrality and land use patterns or commercial activities at interurban or intraurban scales. We considered Shichahai in this study to determine if street centrality applied at the street scale and if the street network was the only factor influencing the selection of store location. First, the nearest neighbor index, nearest neighbor hierarchical spatial cluster(NNHSC), and kernel density estimation(KDE) methods were used to provide baseline spatial distributions of commercial stores. Second, urban network analysis(UNA) tools were used to measure the street centrality indices under two conditions, with and without the weighting of cultural relics calculated by a principal component analysis(PCA). Finally, both store locations and centrality values at nodes were transformed to one unit(raster pixel) for a correlation *** results showed that three of the four store types were clustered and had their own hotspots that were mostly located in the eastern and central parts of city blocks. The most momentous findings were determined from the street centrality indices. Among the three store types with correlation coefficients above 0.5, all centrality indices with landmark weighting, except straightness, had higher correlations,with closeness with landmark weighting having the highest correlation, followed by betweenness with landmark weighting. Therefore,we statistically concluded that street centrality could apply at the street scale and that the street network was not the only factor that influenced store location pattern, with landmarks also playing a significant role. The results provide guidance in determining the selection strategy for stores in a historic conservation area.

关键词： historic conservation area location selected behavior commercialization landmark influence Urban Network Analysis tool street network revival

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

Pedestrian walking speed at un-signalized midblock crosswalk and its impact on urban street segment performance

引用

Journal of Traffic and Transportation Engineering(English Edition) 2021年第1期8卷 57-69页

作者： Albert Forde Janice Daniel Division of Statewide Planning New Jersey Department of TransportationTrentonNJ 08625USA Department of Civil and Environmental Engineering New Jersey Institute of TechnologyNewarkNJ 07102USA

The Urban street Segment Chapter of the Highway Capacity Manual(HCM)includes a methodology for evaluating the level of service urban street segments provide to automobile *** methodology does not account for pedestrian activity at un-signalized midblock crosswalk on an urban street *** activity at un-signalized midblock crosswalk on urban street segments causes friction conditions between automobiles and *** a consequence,the average time it takes vehicles to travel along the segment is *** segment running time decreases both the travel speed of automobiles and the level of service provided to automobile *** is an inverse relationship between the delay incurred by interrupted vehicles and the speeds at which pedestrians walk while crossing at *** account for this delay,there is a need to investigate pedestrian walking speeds at un-signalized midblock *** study measured pedestrian walking speeds by age-group at two un-signalized midblock crosswalks on urban street *** first objective of this paper is to perform statistical analyses to examine the measured free-flow pedestrian walking *** second objective is to demonstrate how the findings of this study can be incorporated into the Urban street Segment Analysis Chapter of the *** walking speeds were recorded and analyzed for 2937 *** results show teenagers walk at an average speed of 1.45 m/s,young adults walk at an average speed of 1.55 m/s,middle age pedestrians walk at a speed of 1.45 m/s,older pedestrians walk at speed of 1.09 m/s,and elderly or physically disabled pedestrians walk at a speed of 1.04 m/s.

关键词： Midblock Pedestrian Walking speed HCM Urban street

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

Vortex street in Homogeneous Dense Dusty Magnetoplasma

引用

Communications in Theoretical Physics 2014年第12期61卷 871-874页

作者：杨建荣吴波毛杰键刘萍王建勇 School of Physics and Electronic Information Shangrao Normal University Department of Physics and Astronomy Shanghai Jiao Tong University College of Electron and Information Engineering University of Electronic Science and Technology of China Zhongshan Institute

For studying the vortex structure in uniform dense dusty astrophysical conditions, a two-dimensional nonlinear equation is derived employing the quantum magnetoplasma hydrodynamic model and considering the strong collisional effect. The coherent vortex solution is obtained by perturbation analysis method. It is shown that the distribution of the electrostatic potential forms spatially a periodic vortex street, and is controlled temporally by the arbitrary function of time that may lead to abundant spacial distributions. It is found that the dust charge number,collision frequency, electron Fermi wavelength and quantum correction all play significant roles to the spatial distribution of vortex street.

关键词： dusty magnetoplasma quantum hydrodynamic model vortex street

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

Health problems among street children seeking care in the Center for Social and Preventive Medicine in Egypt

引用

World Journal of Pediatrics 2017年第5期13卷 503-507页

作者： Hoda Ibrahim Rizk Nihal Mohamed El Rifai Hana Mohamed Aboulghar Public Health and Community Medicine Department Faculty of MedicineCairo UniversityCairoEgypt Pediatrics Department Faculty of MedicineCairo UniversityCairoEgypt

Background:In Egypt,around 1 million children are on the *** children's health is an issue that is not well *** objective of the current study was to determine the health problems of a targeted group of street children seeking medical care and to generate a hypothesis about the positive/negative role of street children care ***:A cross-sectional study was done on 2169 street children who sought medical care at El-Basma clinic at the Center for Social and Preventive Medicine in Cairo University Children Hospital from January 2011 to July ***:Respiratory illnesses and skin problems were the most prevalent conditions,affecting 485 (22.4%) and 359 (16.6%) of the patients,*** issues and trauma were significantly higher among the adolescent *** and gastrointestinal problems were significantly higher among children aged less than 2 *** and cardiac problems were significantly higher among those referred from organizations whereas trauma was significantly higher among those coming directly from the streets.A significant proportion of children at the extremes of the studied age spectrum were coming directly from the *** transmitted infections were rare ***:Respiratory and skin diseases were the major morbidity problems among street children,especially adolescent *** afforded opportunities for access to different health care services.

关键词： Egypt health problems street children

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

Improving urban visibility through fractal analysis of street edges： The case of John Evans Atta Mills Hish street in Accra, Ghana

引用

Frontiers of Architectural Research 2017年第2期6卷 248-260页

作者： R.A. Oppong A.B. Marful E.S. Asare Department of Architecture College of Art and Built Environment Kwame Nkrumah University of Science and Technology (KNUST) Kumasi Ghana

streets are a representation of cities, and the image of a city is a reflection of its home country. Although attempts to ensure harmonious spatial and environmental development in Ghanaian settlements date back to the colonial era, these efforts have minimal physical manifestation in the urban fabric of the city of Accra. The Independence Arch of Ghana, an important landmark in the urban fabric and history of Accra, lacks the striking vista and approach it deserves. This paper introduces the use of fractal analysis of street edges to understand the characteristics of the John Evans Atta Mills （JEAM） High street for developing recommendations to improve visibility along its stretch and the overall image of the city. The box-counting method with visual survey was used in research. The pertinent questions this paper seeks to address are as follows： What factors affect the visibility and imageability of JEAM High street？ What design aspects should be considered to improve urban visibility along JEAM High street？ What is the link of fractals to urban design and architecture？ The paper recommends various design considerations and qualities to improve the urban visibility and imageability of JEAM High street.

关键词： Urban Visibitity street Edge Fractal Urban design

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

Risk factors in street food practices in developing countries:A review

引用

Food Science and Human Wellness 2016年第3期5卷 141-148页

作者： Buliyaminu Adegbemiro Alimi Department of Bioresources Engineering School of EngineeringCollege of AgricultureEngineering and ScienceUniversity of KwaZulu-NatalPrivate Bag X01PietermaritzburgScottsville 3209South Africa

street food trading solves major social and economic problems in developing countries through the provision of ready-made meals at relatively inexpensive prices and employment for teeming rural and urban populace along its value ***,due to informal nature of the enterprise,the activities of the practitioners are not *** gives ample room for unwholesome *** results are the risks such activities pose to the health and safety of practitioners along the value *** review paper,a summary of literature reports on risk factors in street food trade in developing countries and recommended safety intervention,is written with the hope of providing global baseline for intervention to ensure safe food *** of safety approaches that permeates the entire chain of street food business from good agricultural practices through hazard analysis critical control points strategy to good hygiene practices by farmers,vendors and consumers would significantly reduce risks in street food *** all,active collaboration of all stakeholders toward the strengthening and proper enforcement of public health policies to ensure safe practices and engender safer and healthier society is recommended.

关键词： trading street strengthening

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

Formation of Better streets: Interpretation of Urban Design Guidelines for Beijing street Regeneration and Governance

引用

China City Planning Review 2019年第3期28卷 45-55页

作者： Ye Nan Guo Jing Li Min(译) Liu Jiayan(校) the Historic and Cultural City Protection and Research Center Urban Design Department Beijing Municipal Institute of City Planning and DesignBeijingP.R.China 不详

As a showcase for public well-being and urban identity, a better street should carry not only the constantly flowing traffic stream, but also diversified lifestyles and various streetscapes. Beijing is the capital of China, one of its ancient capitals, and a tier 1 international metropolis, both its street connotation and functions are extremely complex. Along with new requirements proposed in the Beijing City Master Plan(2016 – 2035) for controlling construction land, strengthening urban identity, and improving urban governance, the Urban Design Guidelines for Beijing street Regeneration and Governance(the Guidelines) is not only an important breakthrough point for promoting urban transformation to sustainable urban regeneration and governance, but also the foundation of optimizing capital city construction and building a world-class, harmonious, and livable capital city. Taking full consideration of value orientation, technical methods, system design, and governance transformation, the Guidelines adopts five measures, including identity enhancement, coordinated design, enhancing cultural and aesthetic quality, building platforms, and managing 'stubborn diseases' – problems which have plagued people for many years and have been intensifying with years to pass, to comprehensively improve the street design and governance, in the hope of making it a real typical space that represents the image and cultural charm of the capital city.

关键词： Beijing street space urban design regeneration and governance

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

Reflections and Practical Explorations of Rights in street Design

引用

China City Planning Review 2019年第3期28卷 37-44页

作者： Ge Yan Liu Jinxin(译) Liang Sisi(校) Department Four(Urban Design Research Center)of Shanghai Urban Planning and Design Institute School of Architecture and Urban Planning in Tongji University the Urban Design Branch of the Architectural Society of China BeijingP.R.China 不详

street is the public resource of the city. While the street design is seemingly a technical means for physical space, essentially it is the redistribution of urban space rights. This paper argues that street design should focus on the 'street right,' which can be divided into the right to pass and the right to stay, and it may as well be divided into permanent right and process right. Permanent right mainly includes property right and use right, and process right includes participation right and decision-making right. At present, there are many problems confronted by streets in China, such as uncoordinated division of property right between public and private parties, unfair spatial distribution neglecting the use right of slow traffic, less participation and no decision-making right for citizens during street design process, etc. Based on recent design practices in Shanghai, Xiamen, Shangyu, and several other cities, this paper explores strategies in terms of the coordination and integration of property right and space, fair distribution of street use right, and the public empowerment in street design.

关键词： street design permanent right process right property right use right participation right decision-making right practice

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

Theoretical Model on Factors Influencing street Physical Activity from a Social Ecological Perspective

引用

China City Planning Review 2020年第2期29卷 76-85页

作者： Dai Donghui Sun Yu Wang Yaowu Li Min School of Archi-tecture Harbin Institute of Technology(Shenzhen) National First-Class Registered Archi-tect Ph D CandidateSchool of ArchitectureHarbin Institute of Technology(Shenzhen) School of Architecture Harbin Institute of Technology(Shenzhen) 不详

Insufficient physical activity has become a significant issue of global *** optimize the environment of streets,an important kind of public space in cities,is an effective way to push residents to engage in daily physical *** to the complexity of behaviors,identifying the relevant influencing factors and their relationship,as well as building a comprehensive research framework are key to making environmental development ***,from a social ecological perspective,this paper analyzes the basic logic of these influencing factors at various levels and summarizes their specific *** to the rational interpretation on behavioral decision-making based on the theory of health behavior,the paper builds a multi-dimensional model on factors influencing physical activity from theoretical and cognitive *** exploring the model’s structural relationship,it concludes that strategies considering street physical factors are conductive to physical activity interventions from multiple *** theoretical deduction needs to be continuously verified and optimized in empirical studies,it proposes suggestions for the next stage of research on data support of quantitative analysis.

关键词： street physical activity social ecological model theory of health behavior influencing factors

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

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：