论多媒体英语教学

多媒体英语教学把传统英语教学的单调形象转化为动感形象,国内经济社会的发展也需要多媒体英语教学的展开。本文针对英语教学中存在的主要问题：缺乏人际交流、弱化学生主体地位、弱化教师主导作用,提出相关的教学对策：加强英语教学软件的开发与利用,精心设计和制作课件;熟练掌握教学内容;将传统教学媒体与多媒体课件紧密结合;树立对多媒体英语教学的正确认识。     

再生资源行业存在的突出问题及对策探讨

在再生资源回收利用已成为大力推进生态文明建设重要内容的新形势下,着眼于这项工作更好地服务于经济与社会又好又快发展,提出行业目前存在的7个方面的突出问题和解决问题的10项对策,与相关部门和业内人士进行研讨.     

Preparation1 and utilization of wheat straw anionic sorbent for the removal of nitrate from aqueous solution

In order to reduce the impact of eutrophication caused by agricultural residues (i.e. excess nitrate) in aqueous solution, economic and effective anionic sorbents are required. In this article, we prepared anionic sorbent using wheat straw. Its structural characteristics and adsorption properties for nitrate removal from aqueous solution were investigated. The results indicate that the yield of the prepared anionic sorbent, the total exchange capacity, and the maximum adsorption capacity were 350%, 2.57 mEq/g, and 2.08 mmol/g, respectively. The Freundlich isotherm mode is more suitable than the Langmuir mode and the adsorption process accords with the first order reaction kinetic rate equation. When multiple anions (SO42-, H2PO4-, NO3-, and NO2-) were present, the isotherm mode of prepared anionic sorbent for nitrate was consistent with Freundlich mode; however, the capacity of nitrate adsorption was reduced by 50%. In alkaline solutions, about 90% of adsorbed nitrate ions could be desorbed from prepared anionic sorbent. The results of this study confirmed that the wheat straw anionic sorbent can be used as an excellent nitrate sorbent that removes nitrate from aqueous solutions.     

Efficiency of removal of cadmium from aqueous solutions by plant leaves and the effects of interaction of combinations of leaves on their removal efficiency

Removal of cadmium from aqueous solutions using 20 species of plant leaves and combinations of these leaves have been studied. Several factors affecting the removal efficiency have been studied. The most efficient types of plant leaves for the removal of cadmium are those of styrax, plum, pomegranate and walnut. The interaction effect of the combined leaf samples on the efficiency of removal of cadmium has been found to be additive in combinations involving styrax plant leaves but seems to be antagonistic in all other combinations. The optimum experimental conditions for removal of cadmium have been found to be at pH 4.1, using high concentrations of naturally dried plant leaves, using ground leaves and to remove cadmium from agitated aqueous solutions. The percentage of metal removed at an initial cadmium concentration of 10mg/l by the most efficient types of leaves have been found to be 85% for styrax leaves, 85% for plum leaves, 80% for pomegranate leaves, 78% for walnut leaves and 77% for meddler leaves. The presence of foreign ions or complexing agents has been found to reduce the efficiency of removal of cadmium by plant leaves. About 80-85% of the cadmium in charged plant leaves has been released under the influence of changing the pH of the solution, addition of competing ions and the addition of EDTA. The results of removal of cadmium by plant leaves have been found to follow the Freundlich adsorption isotherm, first-order reaction with respect to cadmium and to have intra-pore diffusion as the rate-limiting step.     

自然解决方案的国际经验及其对我国生态文明建设的启示

2019年9月召开的联合国气候行动峰会,确定自然解决方案为应对全球气候变化的重要行动领域,并由中国和新西兰担任牵头国家。近10年,自然解决方案理念发展迅速,联合国环境规划署和世界自然保护联盟等呼吁将自然解决方案作为实现全球可持续发展的核心手段,并提出了具有指导意义的相关标准。本文介绍了自然解决方案的概念、历程与标准,列举了自然解决方案在气候变化、流域修复、生物多样性保护和粮食安全等领域的应用案例,从标准规范、工程管理、体系建设等维度对自然解决方案与我国生态文明建设进行比较,最后提出了有效融合自然解决方案与我国生态文明建设的7条建议。     

铈锆固溶体负载LaCoO3催化碳烟的性能和表征

用柠檬酸法制备了铈锆固溶体负载不同量LaCoO3的催化剂。用热重法测试了催化剂样品对碳烟的催化活性。采用程序升温还原法（H2-TPR）、BET、X-射线衍射仪（XRD）和X-射线光电子能谱仪（XPS）对催化剂进行了测试。结果表明,铈锆固溶体表面形成了稳定的LaCoO3钙钛矿相结构;负载量为30%LaCoO3的催化剂具有最高的催化活性,起燃温度降到530℃;催化剂的催化活性与催化剂还原峰强度以及催化剂表面氧物种OII的含量紧密相关。     

Development and modelling of realistic retrofitted Nature-based Solution scenarios to reduce flood occurrence at the catchment scale

Decentralized Nature-based Solutions such as Urban Green Infrastructures (UGI) are increasingly promoted to reduce flooding in urban areas. Many studies have shown the effectiveness of flood control of UGI at a plot or neighbourhood level. Modelling approaches that extrapolate their flood reducing impact to larger catchment scales are often based on a simplistic assumption of different percentages of UGI implementation. Additionally, such approaches typically do not consider the suitable space for UGI and potential implementation constraints. This study proposes a scenario development and modelling approach for a more realistic upscaling of UGI based on empirical insights from a representative neighbourhood. The results from this study, conducted in the metropolitan area of Costa Rica, show that upscaling the full potential for UGI could significantly reduce surface runoff, peak flows, and flood volumes. In particular, the permeable pavement has the highest potential for flood reducing in public space while cisterns perform best at the property level. These results can guide the formation of policies that promote UGI.Supplementary InformationThe online version of this article (10.1007/s13280-020-01493-8) contains supplementary material, which is available to authorized users.     

Typologies of collaborative governance for scaling nature-based solutions in two strategic South African river systems

Scaled up planning and implementation of nature-based solutions requires better understanding of broad characteristics (typologies) of the current governance and financing landscape, collaborative approaches amidst local complexities, and factors of scalability. An inventory was compiled of water-related ecological infrastructure intervention projects in two river systems in South Africa, incorporating actor, environmental, social, and financial dimensions and benefits. Qualitative participatory analysis revealed eight typologies. Post-hoc classification analysis determined similarities and/or unique characteristics of seven quantitative typologies. Key characterising factors included the complexity/size of financial flows, complexity of partnership/governance arrangements, mandates/goals of actors, type of ecological infrastructure, trade-offs in investment in ecological/built infrastructure, and the model used for social benefits. Identified scalable typologies offer structures suited to increased investment, with other typologies offering specialised local value. A range of ecological infrastructure intervention typologies with differing biophysical and socioeconomic outcomes provide choices for investors with specific goals, and benefits to landscape actors.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01531-z.     

中国排污权交易实践存在的问题及其解决路径

目前,排污权有偿使用和交易作为各地环保工作体制、机制创新的热点,是利用经济手段促进环境保护的有益尝试。本文介绍了我国试点地区开展排污权有偿使用和交易所做的主要工作及其特点,并就面临的问题进行了重点分析,提出了进一步完善的对策措施,为全国范围内开展排污权有偿使用和交易积累了工作经验。     

Market-based solutions: An appropriate approach to resolve environmental problems

It was the first time that the Intergovernmental Panel on Climate Change(IPCC),which was founded in 1988,regarded climate change as a significant international political problem(O’Brien and Williams 2007).Over the next decades,environmentalist and policy makers have been applying many efficient ways to solve various environmental problems and have gained achievements.With the support of successful cases,this paper will focus on the market-based solutions and discuss its advantages compared with the conventional approach.