Characterization of humic acids extracted from the sediments of the various rivers and lakes in China

The humic acids (HAs) isolated from the sediments of the various rivers,lakes,and reservoirs in China were studied using elemental analyzer,fourier transform infrared (FT-IR),and CP/MAS 13C nuclear magnetic resonance (NMR) spectroscopy.The results showed that the HAs were characterized by some common chemical and physicochemical properties,but they also pose some differences in the C-containing functional groups.The C/N,C/H,O/C,and O/H ratios differ widely for the various HAs,showing that the elemental comp...     

Factors influencing the quality of rural human settlements in a peripheral metropolitan area based on a structural equation model: A case study from Beijing

Rural human settlement is a significant indicator of the living standards of rural residents, and its improvement can contribute to promoting the positive interaction between inhabited environment and the social, economic, and resource environment in the countryside. Based on 557 valid questionnaires of satisfaction evaluation of human settlement in the peripheral metropolitan area of Beijing, this paper analyzed the elemental characteristics and factors influencing human settlement quality using multivariate statistical analysis and a structural equation model. The result shows that, first, the rural residents in a peripheral metropolitan area of Beijing are generally satisfied with the quality of human settlement (satisfaction rate is 66.2%). Specifically, the natural and social environment of the countryside is excellent and harmonious and corresponding standard of countryside infrastructure is advanced, but the quality of public services and follow-up management of facilities are in urgent need of improvement and the imbalance between revenue and expenditure of rural households has led to a continuous increase in the pressures of life. Second, factors such as social atmosphere, appearance of the village, entertainment, living costs, fundamental public services, and production costs have significant effects on human settlement quality in this peripheral metropolitan area, with social atmosphere as the main one. Living costs and supporting services are the main constraints to improvement in the quality of human settlement.     

A Structural Equation Model of Residents’ Support for Mega Event

Abstract

The aim of this article is to develop a structural equation model to assess key factors of residents’ support for hosting mega event based on previous literature. The model consisted of five latent constructs and eight path hypotheses. A survey was conducted in Shanghai before 2010 World Expo. It was found that the support for mega events is affected directly and/or indirectly by four determinants factors: perceived benefits, perceived costs, personal benefits and community attachment, and support relies heavily on perceived benefits rather than costs. This study contributes to the existing body of knowledge in an attempt to understand local residents’ support for a mega event in different economic and cultural settings.     

The win-win pathway of economic growth and CO2 emission reduction: a case study for China

ABSTRACT

Continuously reducing the CO₂ intensity of GDP is the core strategy for developing countries to realize the dual targets of economic growth and CO₂ emissions reduction. The measures are twofold: one is to strengthen energy saving and decrease energy intensity of GDP and the other is to promote energy structural decarbonization and reduce CO₂ intensity of energy consumption. In order to control global temperature rise no more than 2°C, the decrease in CO₂ intensity of GDP needs surpass 4% before 2030, but it could be merely about 2% based on the current trend. Therefore, all countries ought to speed up the low-carbon transition in energy and economy. As for China, keeping a continuous decline in CO₂ intensity of GDP of 4%–5% will ensure the realization of the NDC objectives, and also promotes the early peaking of CO₂ emissions before 2030. China will play a positive leading role in realizing a win-win low-carbon development coordinating sustainable development and climate change mitigation.     

Game analysis of Chinese stakeholders in collective forest rights system reform

In the current stage of Chinese forest ownership reform, the central and local governments as well as the forest farmers play different roles with variations in their expected returns. Managing these respective relationships between the forestry stakeholders to maximize their benefits while actively engaging each stakeholder in the collective forest ownership reform process has become an important issue. This study uses the game theory methodology to analyze the relationship between the different reform stakeholders and then builds on the forest farmers’ participation in the reform model process at the reform movement micro-level. This model calculates the forest products equilibrium marketing sales and the government subsidies provided to the forest farmers, when the forest farmers willingly participate in the reform process. It will provide a reliable basis for formulation of government policies which positively impacts Chinese forestry reform.     

水华对沉积物中氮的转化和去除的影响

湖泊富营养化和水华暴发已经成为突出的环境问题之一,了解水华对湖泊氮素的转化和去除的影响,对于削减湖泊氮负荷至关重要.本文研究了水华对沉积物中氮转化和氮转化相关功能基因的影响,并采用结构方程模型分析了水华影响湖泊中氮转化和去除的途径.结果表明,与厌氧氨氧化相比,反硝化作用是太湖沉积物氮削减的主要途径,对沉积物中总溶解性氮去除率的解释度为42. 3%.水华可以直接造成沉积物中TDN和TOC量的增加,提高厌氧氨氧化菌、nir S和nir K的基因丰度,并且间接提高沉积物中氨氮和硝酸盐的浓度,通过增强厌氧氨氧化和反硝化过程加速沉积物中氮的去除.     

装修改造对结构整体安全性影响分析

归纳了危害结构安全的主要装修改造行为,提出装修改造对结构安全性影响应以整体结构为研究对象,分析结构整体抗力的变化。以实际工程为例,对装修改造前后建筑结构进行设计复核,重点分析了建筑荷载增加、承重墙窗下墙拆除对结构安全性的影响。指出在各种装修因素综合作用下,结构承重体系发生改变,尤其是抗震薄弱构件的出现,使结构整体抗震能力大大降低。提出保证建筑结构安全性的合理化建议,对防止突发性灾害具有重要意义。     

高校环境专业实验教学存在的问题及对策

实验教学在高校环境专业教学工作中发挥着越来越重要的作用。通过对高校环境专业实验教学的现状和所存在的问题进行分析,提出了优化实验教学内容、改进实验教学方法和考核方式等改进措施,以提高高校环境专业实验教学水平。     

课证融合模式下实训教学改革研究

课证融合模式就是将课程与职业资格证书相结合的教学模式,是对职业教学改革的探索。但当前存在的实训教学标准模糊、校企合作实训教学条件不足、教师队伍转型滞后、教材开发混乱等现象严重阻碍了课证融合模式的推行,职业院校应当从明确考核评价标准、改进培养方案、加大双师教师的引进和培养、科学开发实训教材等途径进行尝试,推进课证融合。     

基于结构方程模型的安全生产行政执法绩效分析

为加强对企业安全生产的监督和完善行政执法的评估体系,构建了企业安全生产行政执法绩效评估指标体系。利用调查问卷的方式,获得行政执法部门的绩效评价数据。根据结构方程模型(SEM)相关原理设计绩效评价的测量模型,通过AMOS17.0软件对评价体系进行分析,得到各指标的标准化估计值。利用标准化估计值分析各潜变量对企业安全生产执法的影响权重,各观察变量对企业安全生产执法的影响权重,并进行排序,结果显示:行政执法的合法性>执法人员的素质>执法的合理性>执法的文明性>执法的公开性。