In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes a...In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes and transforms land use pattern. However, social and economic development performs unevenly in Yun- nan, supplemented by varied geographical conditions, so that constructing mountain- ous cities should proceed as per local conditions. The research proposed the con- trol of constructing mountainous cities provided crop safety under the principle of farmland protection and measured the quantities of demanded construction lands ac- cording to science of population prediction and ekistics, based on which the control scales of constructing mountainous cities were determined by multiplying basic farm- land coefficient and the area of newly increased construction lands. The research is of significance for guiding the construction of mountainous cities and avoiding the occupation of construction lands on farmlands.展开更多
Objective To develop a preliminary subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative and to evaluate its reliability and validity.Methods The initial items of the sc...Objective To develop a preliminary subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative and to evaluate its reliability and validity.Methods The initial items of the scale were determined based on a review of policy documents and consultations with experts. The final items of the scale were confirmed through individual interviews with residents combined with the discretetrend method, critical ratio method, correlation coefficient method, and factor analysis method. Then, the dimensions of the scale were determined using exploratory factor analysis(EFA). The Cronbach’s α coefficient, split-half reliability coefficient, and confirmatory factor analysis(CFA) were used to assess the reliability and validity of the scale.Results A scale containing five dimensions with 22 items was established, including urban lifestyle,governance, basic functions, environmental sanitation, and amenities. The Cronbach’s α coefficient of the scale was 0.876, and the split-half reliability coefficient was 0.796. The CFA results indicate that each inspection level was within the standard limit.Conclusion The preliminarily subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative demonstrates a high level of reliability and validity. Additional empirical studies should be carried out to further verify the value of the scale in terms of practical application.展开更多
Ba<span style="font-family:Verdana;">sed on the urban resident population statistics from 2005 to 2018, thi</span><span style="font-family:Verdana;">s paper analyzes the distribut...Ba<span style="font-family:Verdana;">sed on the urban resident population statistics from 2005 to 2018, thi</span><span style="font-family:Verdana;">s paper analyzes the distribution and evolution of city scale in China by screening city samples according to the threshold criteria and using empirical research methods such as the City Primacy Index, the Rank-Scale Rule, the Gini coefficient of city scale, Kernel Density Estimation and Markov transfer matrix. The results show that: the most populous city in China has obvious advantages. The population distribution is concentrated in high order cities and in accordance with the law of order</span><span style="font-family:Verdana;">-</span><span style="font-family:""><span style="font-family:Verdana;">scale;the economic scale of cities is in a concentrated state, the gap between the economic development levels of different types of cities is large, and the megacities are more attractive, which to a certain extent limit the development of the scale of the rest of the cities;th</span><span style="font-family:Verdana;">e number of China’s city population is increasing, however, the ga</span><span style="font-family:Verdana;">p between the</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">population scale of other cities and the most populous city continues to be large, and the structure of city population scale is not reasonable enough;megacities and megalopolises keep their original scale levels unchanged to a large extent, and the scale transition between the two types of cities is rather difficult. Finally, based on the explanatory framework of the dynamics of city scale evolution, policy recommendations are proposed to promote a more balanced distribution of city scale.</span>展开更多
场地-城市相互作用(site-city interaction,SCI)效应会显著改变场地地震波场分布及建筑反应,基于SCI效应理论计算研究方法的发展现状,发挥谱元(spectral element,SE)法可快速高效求解三维地震波场传播和多自由度(multi-degree of freedo...场地-城市相互作用(site-city interaction,SCI)效应会显著改变场地地震波场分布及建筑反应,基于SCI效应理论计算研究方法的发展现状,发挥谱元(spectral element,SE)法可快速高效求解三维地震波场传播和多自由度(multi-degree of freedom,MDOF)模型计算量小且可同时模拟大量建筑的优势,同时,结合频率波数域(frequency wave number analysis,FK)方法,以等效地震荷载的方式施加地震波场,建立了FK-SE-MDOF耦合方法,实现了SE-MDOF耦合模型中多种波型(P波、SV波和SH波)的斜入射输入,解决了当前三维SCI效应研究方法中未能同时考虑建筑非线性、频谱特性、地震波波型及入射角度影响的问题。首先对方法原理进行了介绍;然后,通过与振动台试验的对比,验证了方法的正确性;进而,采用该方法建立理想场地-城市建筑群相互作用耦合模型,主要探讨了入射角度和地震波波型对SCI效应的影响,得到了一些有益结论。该方法较为真实地反映SCI效应影响的同时,可反映建筑基础轮廓对地震波场的影响,适用于需考虑建筑轮廓信息的社区尺度SCI效应研究,可为城市规划、抗震设计、风险评估以及震后救援等工作提供定量指导。展开更多
基金Supported by National Natural Science Foundation of China(41261018)Scientific Research Foundation of Yunnan Education Committee(2015YUFEYC011)~~
文摘In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes and transforms land use pattern. However, social and economic development performs unevenly in Yun- nan, supplemented by varied geographical conditions, so that constructing mountain- ous cities should proceed as per local conditions. The research proposed the con- trol of constructing mountainous cities provided crop safety under the principle of farmland protection and measured the quantities of demanded construction lands ac- cording to science of population prediction and ekistics, based on which the control scales of constructing mountainous cities were determined by multiplying basic farm- land coefficient and the area of newly increased construction lands. The research is of significance for guiding the construction of mountainous cities and avoiding the occupation of construction lands on farmlands.
基金supported by Operation Project of Public Health Emergency Response Mechanism of Chinese Center for Disease Control and Prevention [131031001000150001]FIDELIS-Hubei Program [No. 2004-fid-4-034]。
文摘Objective To develop a preliminary subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative and to evaluate its reliability and validity.Methods The initial items of the scale were determined based on a review of policy documents and consultations with experts. The final items of the scale were confirmed through individual interviews with residents combined with the discretetrend method, critical ratio method, correlation coefficient method, and factor analysis method. Then, the dimensions of the scale were determined using exploratory factor analysis(EFA). The Cronbach’s α coefficient, split-half reliability coefficient, and confirmatory factor analysis(CFA) were used to assess the reliability and validity of the scale.Results A scale containing five dimensions with 22 items was established, including urban lifestyle,governance, basic functions, environmental sanitation, and amenities. The Cronbach’s α coefficient of the scale was 0.876, and the split-half reliability coefficient was 0.796. The CFA results indicate that each inspection level was within the standard limit.Conclusion The preliminarily subjective evaluation scale for assessing the built environments of China’s Hygienic City Initiative demonstrates a high level of reliability and validity. Additional empirical studies should be carried out to further verify the value of the scale in terms of practical application.
文摘Ba<span style="font-family:Verdana;">sed on the urban resident population statistics from 2005 to 2018, thi</span><span style="font-family:Verdana;">s paper analyzes the distribution and evolution of city scale in China by screening city samples according to the threshold criteria and using empirical research methods such as the City Primacy Index, the Rank-Scale Rule, the Gini coefficient of city scale, Kernel Density Estimation and Markov transfer matrix. The results show that: the most populous city in China has obvious advantages. The population distribution is concentrated in high order cities and in accordance with the law of order</span><span style="font-family:Verdana;">-</span><span style="font-family:""><span style="font-family:Verdana;">scale;the economic scale of cities is in a concentrated state, the gap between the economic development levels of different types of cities is large, and the megacities are more attractive, which to a certain extent limit the development of the scale of the rest of the cities;th</span><span style="font-family:Verdana;">e number of China’s city population is increasing, however, the ga</span><span style="font-family:Verdana;">p between the</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">population scale of other cities and the most populous city continues to be large, and the structure of city population scale is not reasonable enough;megacities and megalopolises keep their original scale levels unchanged to a large extent, and the scale transition between the two types of cities is rather difficult. Finally, based on the explanatory framework of the dynamics of city scale evolution, policy recommendations are proposed to promote a more balanced distribution of city scale.</span>
文摘场地-城市相互作用(site-city interaction,SCI)效应会显著改变场地地震波场分布及建筑反应,基于SCI效应理论计算研究方法的发展现状,发挥谱元(spectral element,SE)法可快速高效求解三维地震波场传播和多自由度(multi-degree of freedom,MDOF)模型计算量小且可同时模拟大量建筑的优势,同时,结合频率波数域(frequency wave number analysis,FK)方法,以等效地震荷载的方式施加地震波场,建立了FK-SE-MDOF耦合方法,实现了SE-MDOF耦合模型中多种波型(P波、SV波和SH波)的斜入射输入,解决了当前三维SCI效应研究方法中未能同时考虑建筑非线性、频谱特性、地震波波型及入射角度影响的问题。首先对方法原理进行了介绍;然后,通过与振动台试验的对比,验证了方法的正确性;进而,采用该方法建立理想场地-城市建筑群相互作用耦合模型,主要探讨了入射角度和地震波波型对SCI效应的影响,得到了一些有益结论。该方法较为真实地反映SCI效应影响的同时,可反映建筑基础轮廓对地震波场的影响,适用于需考虑建筑轮廓信息的社区尺度SCI效应研究,可为城市规划、抗震设计、风险评估以及震后救援等工作提供定量指导。
