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Fieldwork Test Research of the Impact on Building Physical Environment on Six Types of Atrium Space in Cold Climates 被引量:3
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作者 Ye-Hao Song Jun-Jie Li +2 位作者 Ning Zhu Jia-Liang Wang Zheng-Hao Lin 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第4期84-90,共7页
Since the research on verification to passive design strategies in sustainable building is at the initial stage,and its test method and verification conclusion are not scientific enough to validate,this paper proposes... Since the research on verification to passive design strategies in sustainable building is at the initial stage,and its test method and verification conclusion are not scientific enough to validate,this paper proposes the necessity of building physical environmental monitoring to quantitative optimization of passive strategies efficiency from the perspective of architecture design and building environment. Adopting comparative research method,this research chooses six types of atrium space in cold climate in China as a prototype,focusing on building physical environmental performance difference in and between atrium and building main space. Spatial parameters of the atrium space will be divided into four factors: spatial geometry,interfacial properties,internal and external related categories. With subdividing these four factors into sub-factors,this paper makes crosscomparison among the sub-factors to clarify passive strategies effectiveness in atrium. Data comparison analysis shows that Winter atrium passive strategy in cold regions from traditional view is not obvious in practical application,and test data need to be stratified refined in atrium design in case of optimizing passive strategy from building prototype perspective. 展开更多
关键词 atrium space building physical environment fieldwork test space effect
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Study on the Improvement Strategies of Physical Environment for Square in Severe Cold Regions' Rural Areas 被引量:1
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作者 Xin-Yu Zhang Hong Jin 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第4期18-23,共6页
To improve the comfortable physical environment for square in severe cold regions' rural areas. This paper applies the methods of questionnaires,field testing and statistical analysis to compare and analyze two di... To improve the comfortable physical environment for square in severe cold regions' rural areas. This paper applies the methods of questionnaires,field testing and statistical analysis to compare and analyze two different square cases of Qingyunpu in Liaoning Province,and conclude the main factors which affect the physical environmental comfort. The improvement strategies for physical environment of rural square are put forward from the aspects of site selection,road position,orientation,landscape design,and ground pavement material selection,aiming to provide the design basis for the physical environment of square in severe cold regions' rural areas. 展开更多
关键词 rural areas of severe cold regions SQUARES physical environment improvement strategies
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Design and Simulative Evaluation of Architectural Physical Environment with Ecotect 被引量:3
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作者 LI Kun YU Zhuang 《Computer Aided Drafting,Design and Manufacturing》 2006年第2期44-50,共7页
关键词 architectural physical environment ECOTECT DESIGN ESTIMATION
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Deep reinforcement learning and 3D physical environments applied to crowd evacuation in congested scenarios
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作者 Dong Zhang Wenhang Li +5 位作者 Jianhua Gong Guoyong Zhang Jiantao Liu Lin Huang Heng Liu Haonan Ma 《International Journal of Digital Earth》 SCIE EI 2023年第1期691-714,共24页
To avoid crowd evacuation simulations depending on 2D environments and real data,we propose a framework for crowd evacuation modeling and simulation by applying deep reinforcement learning(DRL)and 3D physical environm... To avoid crowd evacuation simulations depending on 2D environments and real data,we propose a framework for crowd evacuation modeling and simulation by applying deep reinforcement learning(DRL)and 3D physical environments(3DPEs).In 3DPEs,we construct simulation scenarios from the aspects of geometry,semantics and physics,which include the environment,the agents and their interactions,and provide training samples for DRL.In DRL,we design a double branch feature extraction combined actor and critic network as the DRL policy and value function and use a clipped surrogate objective with polynomial decay to update the policy.With a unified configuration,we conduct evacuation simulations.In scenarios with one exit,we reproduce and verify the bottleneck effect of congested crowds and explore the impact of exit width and agent characteristics(number,mass and height)on evacuation.In scenarios with two exits and a uniform(nonuniform)distribution of agents,we explore the impact of exit characteristics(width and relative position)and agent characteristics(height,initial location and distribution)on agent exit selection and evacuation.Overall,interactive 3DPEs and unified DRL enable agents to adapt to different evacuation scenarios to simulate crowd evacuation and explore the laws of crowd evacuation. 展开更多
关键词 Virtual geographic environments crowd evacuation crowd evacuation simulation deep reinforcement learning 3D physical environments
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Archaeological sites distribution and its physical environmental settings between ca 260-2.2 ka BP in Guizhou, Southwest China 被引量:4
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作者 LI Kaifeng ZHU Cheng +4 位作者 JIANG Fengqing LI Bing WANG Xinhao CAO BO ZHAO Xiaofan 《Journal of Geographical Sciences》 SCIE CSCD 2014年第3期526-538,共13页
This study presents an analysis of the spatial-temporal distribution of 230 ar- chaeological sites in Guizhou Province, Southwest China for three selected time periods from the Paleolithic Age to the Shang-Zhou Dynast... This study presents an analysis of the spatial-temporal distribution of 230 ar- chaeological sites in Guizhou Province, Southwest China for three selected time periods from the Paleolithic Age to the Shang-Zhou Dynasties. The relationship between archaeological sites distribution and environmental changes is also discussed based on paleo-environmental proxies of 6480 and δ3C recorded in stalagmites from Southwest China. The results show that: in the Paleolithic Age (260-10 ka BP), archaeological sites were concentrated in the central, northwestern and southwestern parts of Guizhou, where the high-altitudinal karst landforms with many natural caves suitable for human habitation are developed. In the Neo- lithic Age (10-3.6 ka BP), most of human settlements were concentrated in the central, northwestern and southwestern parts, while, a fewer sites were found on river terraces in the southern and eastern parts, and the intermontane basins in the central and western Guizhou. During the Shang-Zhou Dynasties (3.6-2.2 ka BP), the sites were mainly distributed in the intermontane basins and on river terraces, which were suitable for primitive aerial farming. The analysis of paleo-environmental proxies of 6180 and δ3C since 260 ka BP suggested that climate fluctuations had little imPact on human settlements in this study area. The distinct physical environment, especially the spatial patterns of karst landforms and arable land played an important role in the archaeological sites distribution of Guizhou. 展开更多
关键词 Guizhou Province archaeological sites temporal-spatial distribution the Paleolithic Age to theShang-Zhon Dynasties physical environment
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Organizational Modes and Environmental Conditions of the Severe Convective Weathers Produced by the Mesoscale Convective Systems in South China
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作者 张元春 鲁蓉 +1 位作者 孙建华 杨新林 《Journal of Tropical Meteorology》 SCIE 2023年第1期26-38,共13页
Composite radar reflectivity data during April-September 2011-2015 are used to investigate and classify storms in south China(18-27°N;105-120°E). The storms appear most frequently in May. They are either lin... Composite radar reflectivity data during April-September 2011-2015 are used to investigate and classify storms in south China(18-27°N;105-120°E). The storms appear most frequently in May. They are either linear;cellular or nonlinear systems, taking up 29.45%, 24.51% and 46.04%, respectively, in terms of morphology. Linear systems are subdivided into six morphologies: trailing stratiform precipitation(TS), bow echoes(BE), leading stratiform precipitation(LS), embedded line(EL), no stratiform precipitation(NS) and parallel stratiform precipitation(PS). The TS and NS modes have the highest frequencies but there are only small samples of LS(0.61%) and PS(0.79%) modes.Severe convective wind(≥17m s-1at surface level) accounts for the highest percentage(35%) of severe convective weather events produced by cellular systems including individual cells(IC) and clusters of cells(CC). Short-duration heavy rainfall(≥50 mm h-1) and severe convective wind are the most common severe weather associated with TS and BE modes. Comparison of environmental physical parameters shows that cellular convection systems tend to occur in the environment with favorable thermal condition, substantial unstable energy and low precipitable water from the surface to300 hPa(PWAT). However, the environmental conditions favoring the initiation of linear systems feature strong vertical wind shear, high PWAT, and intense convective inhibition. The environmental parameters favoring the initiation of nonlinear systems are between those of the other two types of morphology. 展开更多
关键词 storms composite reflectivity MORPHOLOGY severe convective weather environmental physical parameter
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Geospatial Analysis of Flood Vulnerability Levels Based on Physical Characteristics and Resilience Capacity of Peri-Urban Settlements in Nigeria
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作者 Omobolaji Oluwamuyiwa Afolabi Victoria Ojone Emelu +5 位作者 Elekwachi Wali Maureen Chidinma Orji Lilian Chidinma Bosco-Abiahu Olushola Idowu Tonye Yemi-Jonathan Odinaka Amadi Wali Sunny Oghenefegor Asomaku 《Journal of Geoscience and Environment Protection》 2022年第8期267-288,共22页
Flooding is becoming a yearly reoccurring event in many communities and cities in Nigeria, leading to the destruction of properties and deaths;hence, we must take measures to either prepare for the impact or curb the ... Flooding is becoming a yearly reoccurring event in many communities and cities in Nigeria, leading to the destruction of properties and deaths;hence, we must take measures to either prepare for the impact or curb the occurrence. The study identified flood vulnerability levels of communities in Isoko North LGA based on physical environmental domains such as land use, elevation, and proximity to river channel (drainage) using geospatial techniques. Also, attributes that could contribute to the resilience capacity building of the communities were assessed. From the study, 73.93% of the entire area is moderately and highly vulnerable to flood, while among the communities, seventeen (17) are categorized as moderately vulnerable, and four (4) are lowly vulnerable. The overall resilience capacity of the communities indicated can build a substantial capacity towards community resilience (3.02, 0.06). However, there is a need to encourage collaboration with stakeholders to improve mitigation action and enhance various shortcomings toward resilience capacity building. 展开更多
关键词 Community Resilience Flood Vulnerability Geospatial Analysis physical environment Resilience Capacity
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Evaluation of social network conservation in historical areas of mountainous towns in Chongqing, China 被引量:1
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作者 SHI Ya-ling HUANG Yong +1 位作者 HU Dong-yang WAN Dan 《Journal of Mountain Science》 SCIE CSCD 2020年第7期1763-1775,共13页
Over recent decades,historical areas conservation has become an important strategy to improve urban competitiveness in the global economy.As shown in existing studies that the conservation of historical areas mainly f... Over recent decades,historical areas conservation has become an important strategy to improve urban competitiveness in the global economy.As shown in existing studies that the conservation of historical areas mainly focused on the physical environment,there is still room for the non-physical study,and researches on the social network conservation in mountainous historical areas are particularly insufficient.Therefore,this paper aims to establish an evaluation system which is helpful for the social network conservation of historical areas.The evaluation system is based on social network analysis and the information of social relationships gathered in field surveys using a specifically designed questionnaire method in four mountainous towns in Chongqing,China.And it was analyzed from three perspectives,i.e.,by the basic statistical properties,condensate subgroup,and centrality.Then five analysis indicators were conceived,including density,lambda set,k-core,degree centrality,and betweenness centrality.The analysis results demonstrate that the social networks of the four towns show different indicators,which are respectively relevant to completeness degree,edgerelatedness level,local stability,structural balance,and concentrated trend of social relationships.Results from SNA modeling indicate that neighborhood residents of historical areas who have more stable and healthier social relationships are relatively not easily be destroyed.The results also illustrate that the social networks structure is influenced by the terrain,form,and function of historical areas,and the change of historical areas is caused by"individual-family-society".Finally,the strategies guiding the social network conservation are put forward from two aspects.These findings suggest that the conservation and management of social network and aborigines in historical areas should be emphasized to increase the collective benefits and vitality. 展开更多
关键词 Historical areas Social network analysis physical environment EVALUATION CONSERVATION Mountainous towns
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A Comparison of Relative Humidity between Two Swedish Buildings with Different Ventilation Solutions 被引量:1
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作者 Thomas Alsmo Catharina Alsmo 《Journal of Environmental Protection》 2016年第6期855-873,共19页
This project is based on measurements of the parameter relative humidity, RH (%), in two buildings: one with natural ventilation and one with mechanical ventilation. Both buildings are located in central Sweden, which... This project is based on measurements of the parameter relative humidity, RH (%), in two buildings: one with natural ventilation and one with mechanical ventilation. Both buildings are located in central Sweden, which constitutes a representative climate zone with respect to Swedish conditions. An important factor for the indoor environment, which affects human health and well-being, is the level of the relative humidity, RH (%). Research studies show that the healthiest level should be in the range of 40% - 60%. Surveys have revealed that about 70% of the employees at Swedish offices, schools and kindergartens experience that the air is too dry during the winter season. Previous studies show that the level of relative humidity in the indoor environment influences the prevalence of respiratory infections and allergies. The purpose of this study is to investigate how the relative humidity differ between the two buildings, and if this may be a cause of the health problems that users are affected by. During many years, users have complained about the environment in the building with mechanical ventilation and that they suffer from health problems. The method used in the study is air measurements of the two parameters, relative humidity and air temperature in the two buildings using data loggers. The indoor environment is affected by the outdoor climate and therefore instruments are placed outdoors to record seasonal variations. The measurements were carried out during the period October 2014 to September 2015 to include all of Sweden’s four seasons with completely different climatic conditions. The results of this study show that the relative humidity in the mechanically ventilated building is consistently significantly lower than in the building with natural ventilation whatever the time of year and temperature indoors. This study shows that mechanical ventilation in buildings affects the indoor environment negatively with respect to human health during most time of the year and this fact must be taken into consideration for the existing as well as the planning of new ventilation systems. 展开更多
关键词 HYGIENE Hygiene and Health Air Quality Sick Building Syndrome (SBS) Particle Implication Particle Measurements Indoor environment Indoor Humidity Indoor Temperature Particle Size Particle Amount physical environment
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The Impact of Nature, The Teaching and Learning of Elementary Lessons in Students 9-11 Years Old (Case Study: Shiraz Elementary Schools)
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作者 Neda Mohammadi Sayyid Rasool Keshavarz Zahra Darabi 《Journal of Architectural Environment & Structural Engineering Research》 2021年第1期1-8,共8页
In today’s world some changes have been occurred in human lifestyle,these changes,along with the advantages,have led to a series of disadvantages including their disconnection with the nature.One of the most importan... In today’s world some changes have been occurred in human lifestyle,these changes,along with the advantages,have led to a series of disadvantages including their disconnection with the nature.One of the most important areas to re-establish the relationship is the school.The presence of nature at schools,and holding some classes in nature,in addition to meeting the special needs of children causes their separation from those small and boring classes as well as their interest in courses.This study aimed to investigate the role of nature in children’s learning.For this purpose,third,fourth and fifth grade classes of 3 schools were held outside the school environment and in the nature in 5 courses.The study is a combinational research and field,indirect observation and library data collection methods were applied,where in the indirect observation,two types of questionnaires were prepared related to the students and teachers and were randomly distributed among 580 students and 50 elementary school teachers.Test reliability was assessed using Cronbach’s alpha and it was obtained to be 0.890.The results of this study indicate that the physical place as one of the factors in children’s learning has the maximum impact on teaching and learning of children.At the end of the study and by investigating the existing factors in the environment we understood that the expansion of the nature and natural light of it causes the students’interest in lessons in nature. 展开更多
关键词 Expansion of space NATURE physical environment of the class SCHOOLS Interest in lessons
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Influence of built environment and user experience on the waterfront vitality of historical urban areas: A case study of the Qinhuai River in Nanjing, China
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作者 Jie Ding Lianjie Luo +1 位作者 Xin Shen Yujie Xu 《Frontiers of Architectural Research》 CSCD 2023年第5期820-836,共17页
Urban waterfronts are important gateways that reflect a city’s image and characteristics.Evaluating waterfront vitality and its influencing factors is critical for guiding urban waterfront planning and redevelopment.... Urban waterfronts are important gateways that reflect a city’s image and characteristics.Evaluating waterfront vitality and its influencing factors is critical for guiding urban waterfront planning and redevelopment.Hourly human movement data,provided by the Baidu Heatmap,were used to explore the weekday and weekend urban vitality spatial distribution characteristics of the waterfronts of the Qinhuai River in Nanjing.Global(ordinary least squares)and local(multiscale geographically weighted regression)models revealed the influence of physicaleenvironmental characteristics(objective)and spatial experience evaluation factors(subjective)on urban vitality.(1)The Qinhuai River waterfront urban vitality agglomeration characteristics were similar between weekdays and weekends,and the core vitality areas were distributed in the dense tourism,commercial,and residential areas along the river.(2)The evaluation of catering experience had the strongest positive correlation with vitality,whereas the waterfront distance had the strongest negative correlation.(3)The influence of each factor on waterfront vitality in the study area exhibited considerable spatial differences,with attenuation trends observed from the east-to-west river sections.This study shows the urban vitality distribution characteristics of the Qinhuai River waterfront spaces.Exploring the influence of physicaleenvironmental and spatial evaluation factors on the vitality distribution can provide a scientific basis and reference for urban waterfront planning and redevelopment focusing on cultivating vitality. 展开更多
关键词 Waterfront space Urban vitality physical environment Emotional experience Big data
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Interest-Driven Model for Human Dynamics 被引量:12
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作者 尚明生 陈冠雄 +2 位作者 戴双星 汪秉宏 周涛 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第4期250-252,共3页
Empirical observations indicate that the interevent time distribution of human actions exhibits heavy-tailed features. The queuing model based on task priorities is to some extent successful in explaining the origin o... Empirical observations indicate that the interevent time distribution of human actions exhibits heavy-tailed features. The queuing model based on task priorities is to some extent successful in explaining the origin of such heavy tails, however, it cannot explain all the temporal statistics of human behavior especially for the daily entertainments. We propose an interest-driven model, which can reproduce the power-law distribution of interevent time. The exponent can be analytically obtained and is in good accordance with the simulations. This model well explains the observed relationship between activities and power-law exponents, as reported recently for web-based behavior and the instant message communications. 展开更多
关键词 environmental and Earth science Statistical physics and nonlinear systems
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Evolutionary Prisoner's Dilemma Game Based on Division of Work 被引量:2
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作者 李志华 汪秉宏 +1 位作者 刘润然 杨涵新 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第10期212-215,共4页
We propose a new two-type-player prisoner's dilemma game based on the division of work on a square lattice, in which a fraction of the population μ are assigned type A and the rest B. In a one-shot two-player game, ... We propose a new two-type-player prisoner's dilemma game based on the division of work on a square lattice, in which a fraction of the population μ are assigned type A and the rest B. In a one-shot two-player game, we let both of their original payoffs be scaled by a same multiplicative factor α 〉 1, if two neighboring players are of different types; however we leave the payoffs unchanged if they are of the same type. Then we show that combined with the two-type setup, the square lattice can assist to induce different social ranks according to players' abilities to collect payoffs. Simulation results show that the density of cooperation is significantly promoted for a wide range of the temptation to defection parameters and that there are optimal values for both α and μ leading to the maximal cooperation level. We reach these results by analyzing the distribution of the players in the social ranks and we also show some typical snapshots of the system. 展开更多
关键词 Computational physics environmental and Earth science
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Is the Near-Earth Current Sheet Prior to Reconnection Unstable to Tearing Mode? 被引量:2
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作者 魏新华 曹晋滨 +1 位作者 周国成 符慧山 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第2期330-333,共4页
The tearing mode instability plays a key role in the triggering process of reconnection. The triggering collisionless tearing mode instability has been theoretically and numerically analyzed by many researchers. Howev... The tearing mode instability plays a key role in the triggering process of reconnection. The triggering collisionless tearing mode instability has been theoretically and numerically analyzed by many researchers. However, due to the difficulty in obtaining the observational wave number, it is still unknown whether the tearing mode instability can be excited in an actual plasma sheet prior to reconnection onset. Using the data from four Cluster satellites prior to a magnetospheric reconnection event on 13 September 2002, we utilized the wave telescope technique to obtain the wave number which corresponds to the peak of power spectral density. The wavelength is about 18RE and is consistent with previous theoretic and numerical results. After substituting the wave vector and other necessary parameters of the observed current sheet into the triggering condition of tearing mode instability, we find that the near-Earth current sheet prior to reconnection is unstable to tearing mode. 展开更多
关键词 Plasma physics environmental and Earth science
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ULF Waves Associated with Solar Wind Deceleration in the Earth's Foreshock 被引量:2
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作者 符慧山 曹晋滨 +3 位作者 杨彪 Lucek E Reme H Dandouras I 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第11期258-261,共4页
Characteristics of ULF waves associated with the solar wind deceleration in the Earth's foreshock on 6-7 April 2003 is studied using the wave telescope technique. In the satellite frame, the ULF waves are the left-ha... Characteristics of ULF waves associated with the solar wind deceleration in the Earth's foreshock on 6-7 April 2003 is studied using the wave telescope technique. In the satellite frame, the ULF waves are the left-handed polarized and quasi anti-parallel propagating mode, with a power peak at about 18.63mHz. The wave vector in the GSE coordinates is estimated to be k = (-4.29, 2.28, 1.21)×10^-4 km^-1, In the solar wind frame, the frequency of waves becomes - 9.39 mHz after the Doppler shift correction. The propagation direction of the waves is thus reversed and correspondingly the polarization of the waves becomes right-handed. The above-mentioned characteristics of the ULF waves in the solar wind frame indicate that the ULF waves associated with the solar wind deceleration are the Alfven-whistler waves, which have been frequently reported in both the observations and computer simulations. 展开更多
关键词 Plasma physics environmental and Earth science Astrophysics and astroparticles
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Information Feedback Strategies in a Signal Controlled Network with Overlapped Routes 被引量:2
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作者 田丽君 黄海军 刘天亮 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第7期388-391,共4页
We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers' route choice and the resultant system performance in a signal controlled network with overlapped rou... We investigate the effects of four different information feedback strategies on the dynamics of traffic, travelers' route choice and the resultant system performance in a signal controlled network with overlapped routes. Simulation results given by the cellular automaton model show that the system purpose-based mean velocity feedback strategy and the congestion coefficient feedback strategy have more advantages in improving network utilization efficiency and reducing travelers' travel times. The travel time feedback strategy and the individual purposed-based mean velocity feedback strategy behave slightly better to ensure user equity. 展开更多
关键词 Instrumentation and measurement environmental and Earth science Statistical physics and nonlinear systems
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Heterogeneity of Some Cooperation/Competition Properties 被引量:1
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作者 徐秀莲 付春花 +1 位作者 刘爱芬 何大韧 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第4期253-256,共4页
We show that the heterogeneity index, which was proposed by Hu and Wang [Physica A 387 (2008) 3769], can be used to describe the disparity of the cooperation sharing or competition gain distributions, which is very ... We show that the heterogeneity index, which was proposed by Hu and Wang [Physica A 387 (2008) 3769], can be used to describe the disparity of the cooperation sharing or competition gain distributions, which is very important for understanding the dynamics of a cooperation/competition system. An analytical relation between the distribution parameters and the heterogeneity index is derived, which is in good agreement with the empirical results. Our theoretical and empirical analyses also show that the relation between the distribution parameters can be analytically derived from the so-called Zhang-Chang model [Physica A 360 (2006) 599; 383 (2007) 687). This strongly recommends a possibility to create a general dynamic cooperation/competition model. 展开更多
关键词 environmental and Earth science Statistical physics and nonlinear systems
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A Realistic Cellular Automaton Model for Synchronized Traffic Flow 被引量:1
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作者 赵博涵 胡茂彬 +1 位作者 姜锐 吴清松 《Chinese Physics Letters》 SCIE CAS CSCD 2009年第11期246-249,共4页
A cellular automaton model is proposed to consider the anticipation effect in drivers' behavior. It is shown that the anticipation effect can be one of the origins of synchronized traffic flow. With anticipation effe... A cellular automaton model is proposed to consider the anticipation effect in drivers' behavior. It is shown that the anticipation effect can be one of the origins of synchronized traffic flow. With anticipation effect, the congested traffic flow simulated by the model exhibits the features of synchronized flow. The spatiotemporal patterns induced by an on-ramp are also consistent with the three-phase traffic theory. Since the origin of synchronized flow is still controversial, our work can shed some light on the mechanism of synchronized flow. 展开更多
关键词 environmental and Earth science Statistical physics and nonlinear systems
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Assessment of Primordial Radionuclides in Pakistani Red Bricks and Associated Radiation Doses
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作者 K. Khan A. Jabbar +2 位作者 P. Akhter M. Tufail H. M. Khan 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第3期343-346,共4页
Specific activity of primordial radionuclides and associated radiation hazards due to 40K, 226Ra, and 232Th have been measured in backed red brick samples, collected from five highly populated areas of the North West ... Specific activity of primordial radionuclides and associated radiation hazards due to 40K, 226Ra, and 232Th have been measured in backed red brick samples, collected from five highly populated areas of the North West Frontier Province of Pakistan. For the detection, analysis and data acquisition, a high purity germanium detector was used. Associated external doses were calculated using a Monte Carlo neutron photon transport code. A theoretical model to determine the gamma dose rate at 1 m height from the floor, made of bricks, was employed for the calculation of mass attenuation coefficient and self-absorption in the floor for the gamma energies of these radionuclides and their progeny. Monte Carlo simulation shows that in this study the floor, having more than an effective thickness of 15 cm, contributes very little to the external gamma dose rate. The values of the external dose rate and annual effective dose are found to be much lower than the world average as well as from other countries of the world. 展开更多
关键词 ACCELERATORS beams and electromagnetism Nuclear physics Instrumentation and measurement environmental and Earth science Particle physics and field theory Astrophysics and astroparticles
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Robustness of Cooperation on Highly Clustered Scale-Free Networks
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作者 丛睿 仇原鹰 +1 位作者 陈小杰 王龙 《Chinese Physics Letters》 SCIE CAS CSCD 2010年第3期9-12,共4页
We study the effect of mutation on the evolutionary prisoner's dilemma in highly clustered scale-free networks. It is found that cooperation is more sensitive and vulnerable to strategy mutation in more highly cluste... We study the effect of mutation on the evolutionary prisoner's dilemma in highly clustered scale-free networks. It is found that cooperation is more sensitive and vulnerable to strategy mutation in more highly clustered networks. For small mutation rates, high clustering coefficient promotes cooperation. For medium mutation rates, high clustering coefficient inhibits the emergence of cooperation. For large mutation rates, cooperation is insensitive to clustering property. We provide explanations for the effects of clustering on cooperation with varied mutation rates. 展开更多
关键词 Computational physics environmental and Earth science
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