岩质边坡随机楔体稳定性分析的Monte-Carlo模拟

结构面组合形成的楔体滑动是岩质边坡的一个主要失稳模式.本文依据统计学理论和概率理论,将Monte-Carlo模拟引入到岩质边坡随机楔体的稳定性分析中,通过设定随机过程,计算参数估计量和统计量,研究了节理的随机分布特征,同时建立了随机楔体模型,采用极限平衡理论计算了楔体的破坏概率,并针对实际工程中经常遇到的小楔体失稳概率...     

福建省扁担洋矿区赋煤地层地质特征及资源潜力分析

在充分收集前人地质成果以及邻近矿区地质资料的基础上,分析福建扁担洋矿区含煤地层特征、赋煤构造条件,结合以往地质工作及少量野外地质调查综合分析认为:扁担洋矿区具有一定的煤炭资源潜力,投入适量勘查工作,有望发现较好的煤矿资源。     

中南地区供水厂水质稳定分析及防护技术

文章以中南地区40多个供水厂原水为主要研究对象,针对供水厂原水水质化学稳定性及其控制方法,进行了以下研究:(1)中南地区供水系统原水水质稳定性现状调查;(2)腐蚀产物的物理化学特性;(3)原水水质化学稳定性的变化规律;(4)供水系统水质稳定性的控制方法。为了全面、客观的评价水质化学稳定性问题,本文采用稳定指数和饱和指数配合使用来综合评价水质化学稳定性,并综合考虑pH值、钙离子含量、侵蚀性二氧化碳的影响,研究发现,饱和指数IL小于-0.6、稳定指数IR大于8以及含高浓度侵蚀性二氧化碳会增加水的腐蚀倾向,可根据不同的作用机理选择相应的防护技术。     

不同颗粒龄的好氧颗粒污泥性能的研究

在SBR反应器中,分别以絮状活性污泥培养的好氧颗粒污泥和直接接种的已稳定运行1 a的好氧颗粒污泥为对象,对2种颗粒龄不同的颗粒污泥的形态、理化特性、对有机物降解能力以及微生物活性进行了比较研究.结果表明,小颗粒龄好氧颗粒的平均湿密度、污泥的比重和表示物理强度的完整系数(IC)分别为1.066 g.cm-3、1.013 g.cm-3和98.7%,各指标均高于大颗粒龄好氧颗粒的1.026 g.cm-3、1.010 g.cm-3和98.4%,两者的平均粒径分别为1.9 mm和2.2 mm.小颗粒龄好氧颗粒和大颗粒龄好氧颗粒的沉降速度分别为0.005～0.032 m.s-1和0.003～0.028 m.s-1,前者的SVI较低,且两体系中好氧颗粒的沉降速度均随粒径的增大而增大.两者对COD、NH4+-N的去除率都保持在90%以上和85%左右,从出水COD浓度、NH4+-N浓度和周期试验来看,小颗粒龄好氧颗粒对COD、NH4+-N的去除效果更好,两者对TP的去除率分别维持在40%～90%和32%～85%,但两者对TN的去除效果相差不大,去除率都在80%左右.同时,小颗粒龄好氧颗粒的异养菌比耗氧速率(SOURH)、亚硝酸菌比耗氧速率(SOURNH4)、硝酸菌比耗氧速率(SOURNO2)分别为26.4、14.8和11.2 mg.(h.g)-1,均大于大颗粒龄好氧颗粒的25.2、14.4和8.4 mg.(h.g)-1.综上所述,好氧颗粒污泥由于颗粒龄的不同会具有明显不同的理化性质,颗粒龄小的好氧颗粒具有更好的有机物降解能力、更高的微生物活性和更好的稳定性.     

Trade and the environment: An application of the WIOD database

The new WIOD database allows for improved empirical analysis on a wide range of important environmental research questions.In this paper we demonstrate the scientific power of the WIOD database and analyze very urgent policy questions on the impacts of international trade and structural change on the environment.We apply recent econometric approaches to show the impact of international trade on the environment via its different channels as for instance to increase welfare and potentially affect environmental regulation as well as countries’sector.This approach has become known as the econometric structural decomposition method.In addition to these guidelines by the literature,an econometric panel data approach is offered to shed some light on the impact of structural change and international trade on environmental pressure,where we especially address and solve several endogeneity issues that add further complexity to the analysis.     

Urbanization in Western China

China has experienced considerable urbanization in the past 60 years,especially since the implementation of the Economic Reform and Opening-up Policy in 1978.In 1949,there were only 132 cities with an urban population of 27.4 million,while in 2008 China had 652 cities with a total urban population of 606 million.Such urbanization is attributed to the boost in the number of cities and the urban population.Urban expansion enhanced geographic inequality between the three major regions in China.Compared with the eastern and central regions,western China only has 19%of the total cities and 18%of the urban population.The urbanization rate was 37.2%for the western region in 2008,while it reached 53.3%for the eastern regions and 45.3%for central China.Using a geographic information system(GIS)and statistical analyses,this study aims at explaining the structure and spatial development of urbanization,and highlighting the current issues of urban inequality in western China during the past two decades.The paper drew following conclusions:(1)Urbanization disparities between eastern and western China have become increasingly obvious,but seem to be evolving slowly since the establishment of the government’s Western Development Priority Policy in 2000.(2)Cities of various sizes were expanded in western China,and the main factors affecting the urbanization are population numbers and density,government investment and geographic conditions.(3)Current patterns of urbanization in the western region are distributed unevenly between provinces.     

Technological Progress,Structural Change and China’s Energy Efficiency

Abstract

China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994–2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China’s declining energy intensity.     

Identifying the factors influencing the performance of reverse supply chains (RSC)

This paper aims to extract the factors influencing the performance of reverse supply chains (RSCs) based on the structure equation model (SEM). We first introduce the definition of RSC and describe its current status and follow this with a literature review of previous RSC studies and the technology acceptance model . We next develop our research model and 11 hypotheses and then use SEM to test our model and identify those factors that actually influence the success of RSC. Next, we use both questionnaire and web‐based methods to survey five companies which have RSC operation experience in China and Korea. Using the 168 responses, we used measurement modeling test and SEM to validate our proposed hypotheses. As a result, nine hypotheses were accepted while two were rejected. We found that ease of use, perceived usefulness, service quality, channel relationship and RSC cost were the five most important factors which influence the success of RSC. Finally, we conclude by highlighting our research contribution and propose future research.     

京津冀及周边地区“2+26”城市结构性调整政策的CO2协同减排效益评估

《打赢蓝天保卫战三年行动计划》（"三年行动计划"）明确提出,产业结构调整、能源结构调整、交通结构调整和用地结构调整是大幅减少大气污染物和CO₂排放的重要抓手,这种协同效应非常明显,但在城市群层面还未被量化研究.为此,采用京津冀温室气体-空气污染物协同控制综合评估模型（GAINS-JJJ）,构建了2017年京津冀及周边地区"2+26"城市群基础排放清单,定量分析了"三年行动计划"的实施带来的CO₂和主要大气污染物的排放变化情况.结果表明,与2017年相比,2020年政策情景下"2+26"城市的CO₂、一次PM_2.5、SO₂、NO_x和NH₃的减排量分别为29.1 Mt （相当于2017年排放量的2%）、203.8（21%）、281.8（27%）、485.5（17%）和34.3 kt （3%）,排放量较大的城市或部门都实现了较为明显的减排.碳协同减排效益结果显示,产业结构调整的一系列重大举措（淘汰落后产能、工业锅炉升级改造和散乱污企业综合整治等）取得了良好的CO₂和大气污染物协同减排效应,而不同污染物中NO_x的碳协同减排效应最高.     

基于中美10所高校的应急管理核心知识体系的解释结构模型研究

应急管理涉及多学科、多领域,明确其核心知识体系可以为应急管理相关学科融合和发展提供基础。本文收集了中美两国10所高校15个本科专业225门专业课程,构建解释结构模型进行研究。结果显示：应急管理核心知识体系包括8大类：应急类、防灾减灾类、公共服务和社会管理类、安全生产类、国家安全类、法律类、公共卫生类和综合类。这8大类又分为18个小类,应急类包括为理论、技术方法和应用;防灾减灾类包括理论、过程和单灾种防范;公共服务和社会管理类包括理论与应用;安全生产类包括安全、健康和环境;国家安全类包括国土安全、恐怖主义和国际关系;公共卫生类包括心理和医疗救助;而法律类重在应急相关法律,综合类则表现为多个领域相结合。该体系的构建可以为应急管理相关学科研究提供知识基础,促进各学科领域在应急研究方面融合发展。