枯草芽孢杆菌漆酶与阴离子型聚丙烯酰胺微观作用机理

阴离子型聚丙烯酰胺（HPAM）常用于煤泥水的澄清处理,产生大量的含聚污水将对选煤厂周边环境造成不利影响. 为探究漆酶降解HPAM的微观作用机理,采用对接模拟了HPAM及其脱氨产物聚丙烯酸（PAA）结构模型与枯草芽孢杆菌漆酶（Lac）的结合,根据-CDOCKER_ Energyscore打分最高原则筛选出Lac的最适底物,然后对该最适复合物分别进行基于亲和力虚拟突变和不同温度下的分子动力学（MD）模拟. 结合模式分析表明,Lac对HPAM-3享有最高亲和力,且其结合最好,因此HPAM-3是该酶的最适底物;HPAM比PAA易被Lac降解;Lac可容纳一定碳链长度的HPAM和PAA. 相互作用分析表明,Lac-HPAM-3亲和力最大主要原因是盐桥;TYR133通过形成氢键以稳定Lac-HPAM-2、Lac-HPAM-3和Lac-HPAM-4,而ARG487通过形成疏水以稳定所有的酶-底物复合物. 基于亲和力虚拟突变分析表明,TYR118、TYR133、ARG487和LYS135是Lac降解HPAM-3的关键残基;LYS135和ARG487分别通过形成盐桥和疏水来最大限度地影响酶同底物的亲和力. MD分析表明,Lac-HPAM-3在298 K时总相互作用能、酶骨架RMSD及所有残基RMSF皆最低,因此该复合物在298 K时结合稳定性最佳;308 K时由于酶骨架RMSD最大,导致底物偏离最初对接位置,因此Lac-HPAM-3在308 K时结合稳定性最差. 这些数据为揭示HPAM酶降解过程奠定基础,为将来突变试验来改造酶提供位点支持.     

铁基双金属催化剂耦合过一硫酸盐去除污染物的研究进展

水中难降解有机物对人体健康和生态环境存在潜在威胁,开发稳定、高效和低成本的催化体系对去除水中难降解有机物具有重要意义. 基于硫酸根自由基的高级氧化技术（SR-AOPs）因其氧化能力和适应性受到广泛关注. 铁基双金属催化剂由于能快速活化过一硫酸盐（PMS）而被认为是有效的催化剂,它弥补了单一铁元素催化剂活化效率低和容易产生二次污染等缺陷. 本文综述了铁基双金属催化剂的基本特征,介绍了铁基双金属催化剂的合成方法,并说明其改性方法,接着探讨铁基双金属活化PMS的机理. 最后,指出铁基双金属催化剂活化过一硫酸盐降解有机污染物面临的挑战和未来可能的发展方向.     

黄河流域资源型城市工业绿色转型绩效评价及时空异质性特征

黄河流域资源型城市占流域城市总量半数以上,是流域可持续健康发展的重点地区。随着黄河流域生态保护和高质量发展上升为国家发展战略,科学评估流域内部资源型城市工业绿色转型绩效,识别发展短板和重点难点,对于提升流域发展活力、夯实高质量发展基础具有重要意义。该研究以黄河流域41座资源型城市为研究对象,通过构建工业绿色转型绩效指数,利用SBM‑Undesir‑ able和Malmquist‑Luenberger模型从发展态势和转型幅度两方面对2013—2019年工业绿色转型情况进行定量测度,分析不同类型资源型城市的工业绿色转型差异,并进一步对资源型城市工业转型绩效类型划分。研究发现：①当前黄河流域资源型城市工业绿色发展态势远未达到有效水平,规模化集聚发展是工业绿色转型的重要保障,从城市类型看成熟型和油气型城市发展态势较好,Moran指数结果显示研究区内工业绿色发展态势存在较为明显的空间依存关系,局部空间集聚的特征较为明显。②2013年以来黄河流域资源型城市工业绿色转型幅度较大,技术进步是推动资源型城市工业绿色转型幅度提升的主要原因,从城市类型看衰退型和油气类城市转型幅度明显高于其他类型城市,Moran指数结果显示工业转型幅度在空间上呈随机分布状态。③黄河流域资源型城市工业绿色转型绩效分化趋势较为明显,资源型城市发展态势间差异是造成绩效差异的主要原因,并可进一步划分为工业绿色转型区、发展态势滞后区、转型幅度滞后区以及工业绿色转型滞后区四种类型区。最后,针对不同类型区工业绿色转型特点提出了针对性的对策建议。     

芳香酸稀溶液的络合萃取研究

络合萃取法分离极性有机物稀溶液具有高效性和高选择性.本文利用三辛胺(TOA)或磷酸三丁酯(TBP)为络合剂,四氯化碳、三氯甲烷、正辛醇或煤油为稀释剂,实验测定了苯甲酸、邻硝基苯甲酸稀溶液的萃取相平衡分配系数,讨论了影响因素.实验测定了TOA在不同稀释剂中的表观碱度.提出了同时考虑络合萃取作用和物理萃取作用的平衡分配系数的表达式.     

Real time remote monitoring of air pollutants and their online transmission to the web using internet protocol

Recent advances in both information and sensor technologies have enabled the development of Real Time Remote Monitoring (RTRM) capabilities for environmental management. An online and real time remote monitoring system for air pollution has been designed and installed at a traffic police station at Punjagutta in Hyderabad, India. The system is optimized using electrochemical sensors and a real time particulate matter analyzer. The system also monitors meteorological parameters such as temperature, humidity, rainfall, barometric pressure, wind speed and wind direction. The system periodically monitors both pollution and meteorological parameters at pre- programmed intervals of hr during peak periods and 1 hr during non peak periods of the day and continuously uploads to a predestinated web site (www.appcb.org/home.htm) using File Transfer Protocol. The web site renders a quick, simple and graphical display of air pollution levels and meteorological parameters and their significance to humans. The present paper highlights design considerations of a pollution monitoring system, system hardware and software requirements and practical limitations and future directions for real time remote monitoring of air pollution.     

Effect of Planning for Connectivity on Linear Reserve Networks

Although the concept of connectivity is decades old, it remains poorly understood and defined, and some argue that habitat quality and area should take precedence in conservation planning instead. However, fragmented landscapes are often characterized by linear features that are inherently connected, such as streams and hedgerows. For these, both representation and connectivity targets may be met with little effect on the cost, area, or quality of the reserve network. We assessed how connectivity approaches affect planning outcomes for linear habitat networks by using the stock‐route network of Australia as a case study. With the objective of representing vegetation communities across the network at a minimal cost, we ran scenarios with a range of representation targets (10%, 30%, 50%, and 70%) and used 3 approaches to account for connectivity (boundary length modifier, Euclidean distance, and landscape‐value [LV]). We found that decisions regarding the target and connectivity approach used affected the spatial allocation of reserve systems. At targets ≥50%, networks designed with the Euclidean distance and LV approaches consisted of a greater number of small reserves. Hence, by maximizing both representation and connectivity, these networks compromised on larger contiguous areas. However, targets this high are rarely used in real‐world conservation planning. Approaches for incorporating connectivity into the planning of linear reserve networks that account for both the spatial arrangement of reserves and the characteristics of the intervening matrix highlight important sections that link the landscape and that may otherwise be overlooked. El Efecto de la Planeación para la Conectividad en Redes de Reservas Lineales