中华人民共和国成立70年来生态文明体制变迁的内在逻辑与实践启示

中华人民共和国成立以来,中国共产党带领中国人民不断探索实践生态文明建设。随着人民环境偏好的增强,中国的生态文明体制不断变迁以满足人民日益增长的美好生态环境需要。通过对中国环境管理机构、环境保护政策变迁历程的梳理,可以探析其变迁的内在逻辑和动力机制。中国的生态文明体制变迁始终坚持以人民为中心的发展思想,以适应人民群众环境偏好变化为逻辑起点,并不断通过体制改革来提高环境治理效率和改善环境治理效果。中华人民共和国成立以来生态文明体制的变迁为新时代生态文明建设奠定了基础、指明了方向,在未来建设美丽中国过程中要坚持以人民为中心的发展思想以满足人民环境偏好变化、完善生态文明制度建设为增强环境治理的效果和效率提供保障、以综合治理的思路构建中国特色社会主义生态文明建设的治理体系。     

油气企业供应商管理存在的问题与建议——以CS公司为例

伴随着供应链管理的应用与发展,越来越多的企业认识到必须充分利用内外资源保持自身的竞争实力。作为重要的外部资源,供应商管理关系到企业成本与收益的平衡,而要做好供应端的成本管理首先要做好供应商的选择和优化。针对CS公司的供应商管理现状及存在的问题,探索适应企业的可操作性强的对策,以期为我国大型油气企业的供应商管理实践提供一定的参考。     

复杂山区铁路客运站自动选址研究

无备选站址条件下的客运站自动选址是线站协同优化的前提和基础,而不局限于车站选址的代价最小化,同时考虑连接车站间区间线路的代价具有重要意义。构建复杂山区铁路客运站自动选址模型,首先,建立综合地理信息模型,基于线站一体化的设计理念,实现单个车站选址,确定站心位置及站坪方向;其次,以公路线形优化模型的改进算法完成站—站间自动选线设计;最后,将车站选址代价与区间线路代价紧密结合起来,计算综合代价,实现站址方案的优选。以山区铁路为例对该方法进行验证,结果表明,该方法能高效生成山区铁路车站方案集,并辅助设计人员进行方案优化。     

Dynamic volatility spillovers across oil and natural gas futures markets based on a time-varying spillover method

This paper analyzes dynamic volatility spillovers between four major energy commodities (i.e., crude oil, gasoline, heating oil and natural gas) in the oil-natural gas future markets. We construct a time-varying spillover method by combining the TVP-VAR-SV model and the spillover method of Diebold and Yilmaz (2009, 2012, 2014). We use the spillover method to obtain time-varying total, directional and pairwise volatility spillover indices. Our results summarize as follows: (1) The volatility spillover indices present peaks and troughs during some periods, such as shale gas revolution, financial crisis, and oil price crash; (2) After the U.S. shale gas revolution, the size of volatility spillover from natural gas future market has reduced sharply, but volatility doesn't decouple from the other three oil future markets; (3) The directional spillover is asymmetric. The crude oil and heating oil futures market are main net transmitter of volatility risk information, while the gasoline and natural gas futures markets are the net receiver; (4) For natural gas future market, the pairwise volatility spillover from crude oil future market has the most significant influence.     

Price rigidity in China: Empirical results at home and abroad

This paper explores the price rigidity in China using 259 monthly domestic and foreign macroeconomic time series. A factor-augmented vector autoregressive (FAVAR) model expanded with global components is employed. Three findings are obtained. First, the model shows that common components at home and abroad are the main driving force of price volatility; for price persistence, however, it is the global components that play a major role. Second, there is no clear evidence to show that the price stickiness in China is subject to urban-rural disparities. Last, we observe a relatively active price volatility and high persistence after the 2008 financial crisis, in which domestic components have increasingly significant impacts.     

To walk or not to walk? Examining non-linear effects of streetscape greenery on walking propensity of older adults

Population aging is a conspicuous demographic trend shaping the world profoundly. Walking is a critical travel mode and physical activity for older adults. As such, there is a need to determine the factors influencing the walking behavior of older people in the era of population aging. Streetscape greenery is an easily perceived built-environment attribute and can promote walking behavior, but it has received insufficient attention. More importantly, the non-linear effects of streetscape greenery on the walking behavior of older adults have not been examined. We therefore use readily available Google Street View imagery and a fully convolutional neural network to evaluate human-scale, eye-level streetscape greenery. Using data from the Hong Kong Travel Characteristic Survey, we adopt a machine learning technique, namely random forest modeling, to scrutinize the non-linear effects of streetscape greenery on the walking propensity of older adults. The results show that streetscape greenery has a positive effect on walking propensity within a certain range, but outside the range, the positive association no longer holds. The non-linear associations of other built-environment attributes are also examined.     

Risk spillover between Bitcoin and conventional financial markets: An expectile-based approach

In order to challenge the existing literature that points to the detachment of Bitcoin from the global financial system, we use daily data from August 17, 2011–February 14, 2020 and apply a risk spillover approach based on expectiles. Results show reasonable evidence to imply the existence of downside risk spillover between Bitcoin and four assets (equities, bonds, currencies, and commodities), which seems to be time dependent. Our main findings have implications for participants in both the Bitcoin and traditional financial markets for the sake of asset allocation, and risk management. For policy makers, the findings suggest that Bitcoin should be monitored carefully for the sake of financial stability.     

Exploring travel patterns and trip purposes of dockless bike-sharing by analyzing massive bike-sharing data in Shanghai,China

In recent years, dockless bike-sharing has rapidly emerged in many cities all over the world, which provides a flexible tool for short-distance trips and interchange between different modes of transport. However, new problems have arisen with the fast and extensive development of the dockless bike-sharing system, such as high running expenses, ineffective bike repositioning, parking problems and so on. To improve the operations of the dockless bike-sharing system, this study aims to investigate the travel pattern and trip purpose of the bike-sharing users by combining bike-sharing data and points of interest (POIs). A massive amount of bike-sharing trips was obtained from the Mobike company, which is a bike-sharing operator in China. The POIs surrounding each trip origin and destination were derived from the Gaode Map application programming interface. K-means++ clustering was adopted to investigate dockless bike-sharing travel patterns and trip purpose based on trip records and their surrounding POIs. The clustering results show that on weekdays, bike-sharing trip origin and destination can be divided into five typical groups, i.e., dining, transportation, shopping, work and residential places. Dining is the most popular trip purpose by bike-sharing, followed by the transferring to other transportation modes and shopping. In addition, through understanding the spatial distribution of the bike-sharing usage patterns of five typical activities, strategies for improving the operation of the dockless bike-sharing system are provided.     

网络直播购物情境下的拟剧化营销——基于抖音直播平台的分析与诠释

网络直播购物逐渐成为一种新的网络营销与消费方式。对于该模式的剖析,有助于对网络直播购物这一新兴事物进行全景化的解构与阐释,更好地理解与把握该模式的本质与趋势。本文基于第三方立场与视角,以戈夫曼拟剧理论为基础,锚定抖音平台为实践场景,尝试诠释拟剧理论在网络直播购物情境中的新变化、新形式、新内涵。研究选择Top100网络直播主播为分析对象,采用后台运营数据、页面数据爬虫、人工观察分析等多元数据采集与分析方法,对整个网络直播购物场景进行分析。研究发现,网络直播购物呈现出鲜明的拟剧化营销特质,各类要素间存在循环强化的运行机理,消费者的购物行为有着显著的集体偏好,且主体间的协同合作机制促进了消费的延续。该发现有助于对拟剧化营销运行机制、拟剧理论的新场景及网络直播购物这一新兴商业模式进行客观辩证的思考。     

组织支持感与员工创造力——相对组织支持感和情感承诺的影响

从自我提升视角出发，基于社会比较理论与社会交换理论，分析组织支持感影响员工创造力的过程机制，相对组织支持感的调节作用以及情感承诺与创造力之间的曲线关系。基于458份企业员工与主管的配对样本，研究结果表明：相对组织支持感显著正向调节了组织支持感与情感承诺之间的关系，情感承诺与员工创造力呈显著的倒U型关系，情感承诺在组织支持感与创造力关系之间起到了瞬时中介作用。研究结果拓展了对组织支持感的影响机制及其边界条件的分析，深化了情感承诺与员工创造力关系的检验。