大气颗粒物污染视角下的城市街区健康规划策略

城市街区是城市肌理、空间形态、功能管理与城市健康环境建设的基本单元,应对以PM10、PM2.5为主要污染物的大气颗粒物污染,具有较高的实操性。基于城市街区影响大气颗粒物浓度与分布的要素、作用路径,以及国外城市应对大气污染的空间规划策略的经验总结,从控源、引流、集汇三方面提出基于大气颗粒物污染改善的街区空间环境优化设计方法与规划指引内容。旨在为我国普遍的城市街区提出空间形态优化策略,塑造生态健康的城市基本单元。     

环境污染与区域经济竞争力互动关系的研究 ——基于西部地区面板VAR模型的实证分析

采用1994-2016年西部地区面板数据,构建面板向量自回归(PVAR)估计模型,实证分析环境污染与经济竞争力之间的动态关系,结果表明：①西部地区环境污染与经济竞争力之间存在交互影响的互动关系,二者之间的关系符合环境库兹涅茨(EKC)曲线的特征。②环境污染与经济竞争力之间不存在长期协整关系,但存在双向的格兰杰因果关系。方差分解结果表明,经济竞争力对环境污染变动的贡献度较大,而环境污染对经济竞争力的影响较小,说明西部地区经济竞争力的提升是以加剧环境污染为代价,而环境污染并不是阻碍经济竞争力提升的重要因素。因此,西部地区应注重产业结构调整与升级,大力发展绿色经济;促进贸易与环境、区域与环境的协调发展;提高环境规制水平,降低污染排放,实现环境保护与经济发展的协同机制。     

The effects of high-speed rail on air passenger transport in China

This study investigates the effects of high-speed rail (HSR) on China’s air passenger transport from the perspective of airports. The difference-in-differences approach is used with unbalanced panel data of 206 airports over the period from 2006 to 2015. Our estimation results found that the negative effects of HSR on the growth rate of China’s air passengers is both statistically and economically significant. However, these adverse effects are not catastrophic.     

环保约谈能否促进企业绿色投资

环保约谈制度是提高环境治理水平所实行的环境执法监督新方式,对于破解环境治理难题,提高环境治理绩效至关重要。本文利用环保约谈所产生的准自然实验变化,以2013—2019年我国重污染行业上市公司为研究样本,考察环保约谈对企业绿色投资的影响。双重差分法的检验结果表明：在环保约谈所涉及城市的上市公司中,环保约谈促进了企业绿色投资。在此基础上,进一步检验发现,环保约谈对绿色投资的促进效果较为明显的企业主要来自于全要素生产率较高,行业市场竞争程度低及融资约束低的企业。研究结论从企业加强环保绿色投资决策的角度为环保约谈的经济后果提供了微观的证据,这不仅对于我们了解环保约谈这一政策对微观主体企业的影响效应具有一定意义,同时,对国家在经济发展中,如何实施更好的环境治理政策具有一定的指导意义。     

一种多传感器空情信息融合算法

针对防空指挥系统快速反应决策能力要求,给出了可行的系统信息融合处理软件组成结构及功能描述,提出了一种适用于快速空情信息融合的通用信息融合处理方法和模型算法。建模过程中,提出的信息融合处理方法和模型算法将防空指挥系统信息融合的复杂过程条理化、公式化和数字化。仿真结果证明,该方法是正确和有效的。目前,该方法已应用到实际工程中。     

码分无线射频识别系统空中接口协议设计及性能分析

为进一步提高无线射频识别系统单个读写器识别电子标签的速率,设计了一种将码分与统计时分技术相结合的新型无线射频识别系统的空中接口协议,并分析了系统的抗噪声性能、识别速率等主要性能指标。仿真结果表明,新型无线射频识别系统在抗噪声性能和识别速率等方面均优于基于现有国际标准ISO/IEC 18000-6C的无线射频识别系统。     

Economic contribution of essential air service flights on small and remote communities

The Essential Air Service Program (EAS) has attracted considerable criticism and has been a target for either modification or complete termination almost since its inception through the Airline Deregulation Act in 1978. Although its opponents emphasize the program's inefficiency, its supporters claim that the program is crucial to accessing small and remote communities, which helps them develop economically and socially. This paper demonstrates the economic contributions of EAS flights to small and remote communities. Using a two-stage least squares estimation, the major findings indicate that a 1% increase in air passenger traffic in EAS airports with a minimum annual air passenger traffic of 1000 likely leads to a 0.12% increase in per capita income of the community served by that airport. Our results also suggest that EAS communities that are able to sustain their subsidized flights experienced higher per capita income growth in the 1999–2011 period than did ex-EAS communities that lost their flights as a result of non-eligibility.     

关于美国战争费用的启示

本文以本次局部战争为案例,根据目前披露出来的一些数据进行初步的分析,希望能够为我们了解美国战争费用的总体情况提供参考。     

Natural and anthropogenic influences on the year-round temperature dynamics of air and water in Postojna show cave,Slovenia

Air and groundwater temperatures were measured in a rimstone pool in Postojna Cave, to advise evaluation of the impact of natural and anthropogenic influences related to heat being initially transmitted into cave air by visitors. Such heat can accumulate both in the rock mass and in water. Results show that attention must be paid to temperature changes of rimstone pool water rather than those of cave air, especially during the winter. Thanks to good ventilation deep inside the cave, short-term air temperature increases related to higher visitor numbers have not influenced flowstone precipitation or the cave fauna. However, this situation might change if winter visitor numbers increased greatly. This study does not support a suggested increase in winter visits (currently the tourism low-season) and reduction of summer visits (currently the tourism high-season).     

基于动态面板数据模型分析FDI的环境效应

外商直接投资在对中国经济增长起到积极推动作用的同时,我们也不可忽视其可能会对我国环境造成的影响。文章通过构建环境污染综合指数,并且以东中西部为三个横截面建立动态面板数据模型来分析外商直接投资对各个地区环境的影响。结果显示,外商直接投资和东部中部地区的环境污染指数之间有正相关关系,和西部地区的环境污染指数之间是一个负相关关系。