北京低收入社区居民社会公平感知的 影响因素研究：基于空间公平视角     

康雷  张文忠  党云晓  杨兆萍  刘彩彩 《世界地理研究》2022,31(1):201-213

随着北京市“国际一流的和谐宜居之都”建设步伐的加快,城市低收入社区居民的社会公平满意度越来越受到重视,居民的居住环境空间公平将受到更多的关注。本研究结合地理学和社会学对居住环境空间公平相关理论,基于2017年北京典型低收入社区的调研数据,实证分析了居住环境主客观条件对低收入社区居民社会公平感知的影响。结果发现：不同类型社区的居民社会公平感知水平差异明显;服务设施、就业可达性和建成环境对个体社会公平满意度也均有不同程度的影响,居住环境满意度对低收入社区社会公平感知的影响中存在调节效应,同时居民社会公平满意度因居民社会经济属性而异。  相似文献   

Influence of temperature and humidity on similar material and its control measures     

Jianfeng Zha  Huaizhan Li  Guangli Guo  Jintao Wang 《Environmental Earth Sciences》2017,76(21):740

Similar-material simulation is generally used in mining engineering. The properties of a similar material vary over time in a certain environment. Due to the time-varying characteristics of the material strength, the model and prototype is dissimilar in dynamics and kinematics, which may affect the reliability of simulation results. The present paper conducts block experiments that investigate the time-varying characteristics of the material strength. The paper further investigates methods of reducing the effects of time-varying characteristics of material strength on simulation results and extends the effective monitoring time of the similar-material model in a natural environment and an environment having constant temperature and humidity. The following results are obtained: (1) The strength and moisture content of the similar material have an exponential relationship, which can be divided into three phases. (2) When a similar-material model is laid in a natural environment, sampling and homemade monitoring equipment can be adopted to control the similar-material model’s strength. Meanwhile, homemade monitoring equipment for the relative humidity of the similar material can be used to monitor a critical change in the similar material’s moisture content. (3) An environment having constant temperature and humidity can extend the effective monitoring time of the similar-material model. (4) High humidity can extend the effective monitoring time while high temperature can decrease the effective monitoring time. In an experiment, the temperature and humidity under the environment of constant temperature and humidity and monitoring time of the model should both be set reasonably. Results provide guidelines for setting the model monitoring period and give evidence for the reliability of simulation results.  相似文献   

汉江上游郧县庹家湾剖面光释光测年及意义     

张文桐  庞奖励  黄春长  周亚利  查小春  崔天宇  王海燕  杨丹 《中国沙漠》2017,37(5):885-892

在野外考察基础上选择湖北郧县庹家湾剖面为研究对象。在对磁化率和粒度进行分析的同时,用单片再生剂量法进行了光释光测年（OSL）地层断代。OSL测年数据显示：剖面样品年龄处在55.11~13.57 ka BP,且与地层深度呈现出良好的对应关系,此剖面为黄土风化堆积形成。黏粒含量、黏粒/粉砂值以及磁化率值等气候替代性指标数值在马兰黄土层228~260 cm和294~370 cm深度明显高于典型马兰黄土（L₁）,具有明显的成壤特征,通过OSL测年数据判断时间为27.26~21.59 ka BP,说明在晚更新世时期气候并非持续稳定的寒冷干旱,而是具有一定的波动,在此期间气候相对温暖湿润,而且此次气候事件在黄土高原地区其他沉积记录中也有良好记录。  相似文献