Oxidation of As(Ⅲ) by potassium permanganate

The oxidation of As(Ⅲ) with potassium permanganate was studied under conditions including pH, initial As(Ⅲ) concentration and dosage of Mn(Ⅶ). The results have shown that potassium permanganate was an effective agent for oxidizing of As(Ⅲ) in a wide pH range. The pH value of tested water was not a significant factor affecting the oxidation of As(Ⅲ) by Mn(Ⅶ). Although theoretical redox analyses suggest that Mn(Ⅶ) should have better performance in oxidization of As(Ⅲ) within lower pH ranges, the experimental results show that the oxidation efficiencies of As(Ⅲ) under basic and acidic conditions were similar, which may be due to the adsorption of As(Ⅲ) on the Mn(OH)2 and MnO2 resulting from the oxidation of As(Ⅲ).     

Field‐Scale Application of Three Types of Neural Networks to Predict Ground‐Water Levels1

Abstract: In this paper, a field‐scale applicability of three forms of artificial neural network algorithms in forecasting short‐term ground‐water levels at specific control points is presented. These algorithms are the feed‐forward back propagation (FFBP), radial basis networks (RBN), and generalized regression networks (GRN). Ground‐water level predictions from these algorithms are in turn to be used in an Optimized Regional Operations Plan that prescribes scheduled wellfield production for the coming four weeks. These models are up against each other for their accuracy of ground‐water level predictions on lead times ranging from a week to four weeks, ease of implementation, and execution times (mainly training time). In total, 208 networks of each of the three algorithms were developed for the study. It is shown that although learning algorithms have emerged as a viable solution at field scale much larger than previously studied, no single algorithm performs consistently better than others on all the criteria. On average, FFBP networks are 20 and 26%, respectively, more accurate than RBN and GRN in forecasting one week ahead water levels and this advantage drops to 5 and 9% accuracy in forecasting four weeks ahead water levels, whereas GRN posted a training time that is only 5% of the training time taken by that of FFBP networks. This may suggest that in field‐scale applications one may have to trade between the type of algorithm to be used and the degree to which a given objective is honored.     

The circular economy in China

This article makes an attempt to answer the three questions of why China is devoting its full effort to promoting a circular economy, what a circular economy is, and how to implement a circular economy in China. The evolutionary process of a circular economy in China, from introduction of the concept and the relevant actions of national decision making to demonstration of the system nationwide, has taken only around 6 years, with strong encouragement from politicians and the urgent need to cope with environmental pollution and a severe shortage of natural resources. The circular economy in China is now being actively implemented at three levels: enterprises, eco-industrial parks, and regions. The consolidated theoretical bases of ecology and economics have helped the circular economy to define its position as a new economic model to effectively resolve the problems of resources and the environment. In this regard, material flow management is naturally a unique planning and management method for implementation of a circular economy, and eco-efficiency is a good indicator to measure circular economic activities. Of particular significance has been initiation of the legislative process for the Circular Economy Law, which is among a number of initiatives developing core policies for a circular economy in China. Stringent enforcement of a set of policies for energy saving and pollution abatement nowadays in China will certainly create an enabling environment for the development of a circular economy.     

对我院英语分级教学的进一步探索

我校从2005年开始在大一年级试实施分级教学，一个学期的教学实践证明我们的改革是可行的，我们的分级教学取得了初步的效果。     

生物滴滤床降解有机废气净化效率的理论模型

将生物膜滴滤塔内的多孔填料简化为壁面覆盖有生物膜的平行平板通道,建立了一个净化低浓度有机废气的理论模型.该模型首先运用两相流理论获得了通道内液膜厚度,然后通过污染物在气相、液相的质量组分方程,结合生物膜内的传质与不考虑氧限制的生化反应动力学方程,获得了污染物在液相和生物膜中浓度分布的近似分析解,最终得到污染物在气相中沿塔高的浓度分布及废气净化效率.模型的理论预测值与生物膜滴滤塔净化低浓度甲苯废气的实验结果基本吻合.     

基于RBF和PSO的双喉道气动矢量喷管优化设计

本文探索了一种能多变量综合优化的方法,即对喷管进行参数化设计后,用均匀试验设计(UED)将试验样本均匀散布在设计区间内,求出各性能参数后,利用径向基神经网络(RBF)对试验样本进行拟合,再用粒子群算法(PSO)对训练好的神经网络进行寻优,找出了更好的双喉道气动矢量喷管设计参数组合。数值模拟结果显示,优化后的双喉道气动矢量喷管的矢量角有了明显提高。试验表明这种优化方法具有很好的优化能力,可以用来对喷管几何外形进行参数优化。      

游憩导向下国土空间生态修复的理论与模式

游憩导向下国土空间生态修复是将受损生态空间保护与休闲空间融合的重要手段,是构建山水林田湖草命运共同体与提高人类福祉的重要内容。基于国内外研究现状,界定了游憩导向下国土空间生态修复的概念,提出其应遵循生态系统服务理论、人地关系地域系统理论、区位理论、景观基因理论、大地艺术理论五大理论逻辑。基于实践案例归纳了游憩导向下生态修复模式类型、特征与问题,并提出实践模式的五大优化路径,包括明确功能适宜、效益最优的修复导向,建立多级空间尺度联动的传导机制,提升游憩导向下生态修复地的地方嵌入性,加强修复效果的动态监测评估,构建可持续的建设与运营管理模式,以期为游憩导向下国土空间生态修复和保护提供理论和实践参考。     

新时期国土空间安全背景下的空间规划系统思考

当前,国土空间治理模式正由原空间规划“集群”向统一的国土空间规划转变,国土空间安全这一空间发展底线问题成为规划各界热议的焦点。基于系统理论,梳理了国土空间及其规划系统,重点分析了具有什么系统性质的空间规划才能更好地保障国土空间安全。研究表明：（1）国土空间规划完善的法律体系与科学的系统接口是保障国土空间系统安全的关键; （2）国土空间规划立法,应构建以国土空间规划法作为基本法,形成以法律法规、标准体系为核心的结构清晰、内容统一的法规体系,以使空间规划系统结构合理;（3）系统接口方面,建立以硬件接口和软件接口为主要类型、国土空间规划全生命周期为核心的三维系统接口,实现“五级三类四体系”的三维衔接。     

基于综合主成分及径向基网络的环境质量评价

运用综合主成分分析对监测数据进行处理,集成径向基函数人工神经网络(RBF-ANN),参考国家环境质量评价标准设定RBF的学习样本,从而构建区域环境质量综合评价模型,对安徽省合肥市新站综合开发试验区进行环境质量综合评价。实例分析结果表明,运用综合主成分法可以精准的统计出一个区域的环境综合数据,而且在matlab环境下运用RBF-ANN模型既可以准确,客观的评定环境质量的等级,又可以表现其环境污染的具体程度,能在同一评价等级内对不同环境质量的评价对象进行更加细微的污染程度的比较。结果表明,合肥市新站综合开发试验区环境综合质量介于轻度污染和中度污染的标准极限值之间,属于中度污染。     

论公众参与环境保护的理论基础

公众参与原则具有保障环境法基本价值实现的重要功能。基于环境经济学、产业经济学、环境管理学、博弈制度变迁理论、环境法理等学科背景,环境管理权来源理论、博弈制度变迁理论、有效社会监督理论和环境权理论分别构成了公众参与环境保护的坚实埋论基础。