Urban Energy Efficiency from Cities in China and Policy Implications

Using 1995-2006 panel data for 210 cities, this article firstly measures total factor energy efficiency for Chinese cities with constant return to scale data envelopment analysis model,and then describes the features of regional differences. The results show that the changing trend displays four "reversed U" shapes. A turning point of widening gap occurred among cities in 2000 and there was a certain convergence among four regions. Urban energy efficiency level is unstable. Cities with low efficiency and high energy input will be the focus of energy-saving and reducing emissions. According to Tobit model, resource endowment, temperature, industrial structure, technology level and variety of policy factors should be treated differently in different situations.     

Vehicle emission implications of drivers’ smart advisory system for traffic operations in work zones

Wireless communication systems have been broadly applied in various complicated traffic operations to improve mobility and safety on roads, which may raise a concern about the implication of the new technology on vehicle emissions. This paper explores how the wireless communication systems improve drivers’ driving behaviors and its contributions to the emission reduction, in terms of Operating Mode (OpMode) IDs distribution used in emission estimation. A simulated work zone with completed traffic operation was selected as a test bed. Sixty subjects were recruited for the tests, whose demographic distribution was based on the Census data in Houston, Texas. A scene of a pedestrian’s crossing in the work zone was designed for the driving test. Meanwhile, a wireless communication system called Drivers Smart Advisory System (DSAS) was proposed and introduced in the driving simulation, which provided drivers with warning messages in the work zone. Two scenarios were designed for a leading vehicle as well as for a following vehicle driving through the work zone, which included a base test without any wireless communication systems, and a driving test with the trigger of the DSAS. Subjects’ driving behaviors in the simulation were recorded to evaluate safety and estimate the vehicle emission using the Environmental Protection Agency (EPA) released emission model MOVES. The correlation between drivers’ driving behavior and the distribution of the OpMode ID during each scenario was investigated. Results show that the DSAS was able to induce drivers to accelerate smoothly, keep longer headway distance and stop earlier for a hazardous situation in the work zone, which driving behaviors result in statistically significant reduction in vehicle emissions for almost all studied air pollutants (p-values range from 4.10E-51 to 2.18E-03). The emission reduction was achieved by the switching the distribution of the OpMode IDs from higher emission zones to lower emission zones.

Implications: Transportation section is a significant source of greenhouse gas emissions. Many studies demonstrate that the wireless communication system dedicated for safety and mobility issues may contribute to the induction in vehicle emissions through changing driving behaviors. An insight into the correlation between the driving behaviors and the distribution of Operating Mode (OpMode) IDs is essential to enhance the emission reduction. The result of this study shows that with a Drivers Smart Advisory System (DSAS) drivers accelerated smoothly and stopped earlier for a hazardous situation, which induce the switch of the OpMode IDs from high emission zones to lower emission zones.     

Economic and environmental value stream map (E2VSM) simulation for multi-product manufacturing systems

Value stream mapping (VSM) is a well-accepted tool within lean manufacturing concept which is often used for analysing and designing the flow of materials and information required to manufacture a product. However, the analysis is static and single product oriented, which fails to cope with either the variation of production plan or a multi-product environment. In addition, the environmental impact of a manufacturing system is highly associated with the dynamic consumption of energy and resources. Despite the recent integration of VSM with simulation or environmental studies (in the domain of energy efficiency), still neglected is the dynamic assessment of all the resources involved in a multi-product production environment. This paper presents a methodology for modelling multi-product manufacturing systems with dynamic material, energy and information flows with the aim to generate economic and environmental value stream maps (E²VSM). The proposed methodology is validated with an industrial case.     

The influence of Chinese population policy change on resources and the environment

Universal two-child policy has been implemented since the end of 2015 in China. This policy is anticipated to bring a significant increase in the total population, with profound influences on the resources and environment in the future. This paper analyzes the changing dynamics of urban and rural population, and forecasts urban and rural population from 2016 to 2030 at national and provincial scale using a double log linear regression model. Drawing upon the results of these two predictions, the impact of the population policy change on Chinese resources consumption and environmental pollution are predicted quantitatively. Given the future total population maintains current levels on resources consumption and environmental emission, the additional demand of resources and environment demand for the new population is forecasted and compared against the capacity on supply side. The findings are as follows: after implementing the universal two-child policy, China’s grain, energy consumption, domestic water demand, and pollutant emissions are projected to increase at different rates across provinces. To meet the needs arising from future population growth, food and energy self-sufficiency rate will be significantly reduced in the future, while relying more on imports. Stability of the water supply needs to be improved, especially in Beijing, Henan, Jiangsu, Qinghai, and Sichuan where the gap in future domestic water demand is comparatively larger. Environmental protection and associated governing capability are in urgent need of upgrade not least due to the increasing pressure of pollution.     

国外流域管理的成功经验对雅砻江流域管理的启示

世界各国对流域管理的不断探索,大大丰富了流域管理的理论和实践,流域管理已成为国家和地区水资源管理的一种行之有效的模式。我国的流域管理尚处于最初的探索阶段,如何借鉴国外流域管理的成功经验,形成有效的流域管理模式已成为我国水资源管理的主要任务之一。为了给国内流域管理实践提供一些有益的借鉴,分析总结了具有代表性的美国田纳西河流域管理模式、澳大利亚墨累 达令河流域管理模式和英国泰晤士河流域管理模式的成功经验和存在的问题。以雅砻江流域水电开发为实例,在对该流域的实际情况进行全面分析的基础上,将该流域与上述三条流域进行比较,充分借鉴三条流域管理模式成功经验,提出了雅砻江流域管理的相关对策和建议。     

烟草烟雾对室内空气颗粒物浓度的影响

采用电称冲击低压系统(ELPI)将无烟室和吸烟室内的空气颗粒物(0.03～10.00 μm)分成12级,对其粒子数和质量浓度进行测定.结果表明,吸烟室PM0.03～10.00的日平均粒子数和质量浓度分别是无烟室的1.50、1.13倍.烟草烟雾对室内颗粒物粒子数的影响集中在0.03～1.00 μm粒径段;对室内颗粒物质量浓度的影响表现为双模态结构,峰值分别在0.20～0.70、5.00～8.20 μm粒径段.烟草烟雾颗粒物的粒子数和质量浓度随烟雾消散时间的增加而减少,粒径越小,减小的越明显;烟草烟雾颗粒物在室内消散缓慢,会在长时间内造成影响,应引起足够关注.     

温度对17α-乙炔雌二醇在SBR工艺中去除效果的影响

17a-乙炔雌二醇(EE2)属于人工合成雌激素,是活性较强的环境内分泌干扰物之一.在污水处理厂中,EE2主要是通过活性污泥的生物降解作用得以去除.影响活性污泥对EE2生物降解的因素很多,温度是影响因素之一.分别采用一级缺氧/好氧(A/O)模式和三级缺氧/好氧(A/O/A/O/A/O)模式运行的SBR工艺.考察了温度对EE2去除的影响.试验发现,随着温度的升高,EE2在水相和泥相中的去除率明显增加,其中在30℃时EE2去除率达到最大,2种运行模式下水相中EE2去除率均达到了96%以上;泥相是EE2生物降解的主要场所;EE2生物降解主要发生在好氧阶段,缺氧阶段EE2生物降解效果不明显.     

GC/MS法测定润滑油基础油中多环芳烃

对润滑油基础油中多环芳烃的气相色谱/质谱(GC/MS)测定方法进行了研究,探讨了样品的提取,固相萃取柱净化等前处理方法,同时也对仪器测定条件进行了优化.结果表明,在检测润滑油基础油中多环芳烃时,经优化的GC/MS法的加标回收率和精密度均达到较满意的水平.