High performance of multi-layered alternating Ni–Fe–P and Co–P films for hydrogen evolution

Judiciously engineering the electrocatalysts is attractive and challenging to exploit materials with high electrocatalytic performance for hydrogen evolution reaction. Herein, we successfully perform the interface engineering by alternately depositing Co–P and Ni–Fe–P films on nickel foam, via facile electroless plating and de-alloying process. This work shows that there is a significant effect of de-alloying process on alloy growth. The electronic structure of layered alloys is improved by interface engineering. The multilayer strategy significantly promotes the charge transfer. Importantly, the Co–P/Ni–Fe–P/NF electrode fabricated by interface engineering exhibits excellent electrocatalytic hydrogen evolution activity with an overpotential of 43.4 mV at 10 mA cm-2 and long-term durability for 72 h in alkaline medium (1 mol L-1 KOH). The innovative strategy of this work may aid further development of commercial electrocatalysts.     

Accumulation of potentially toxic trace elements (PTEs) by native plant species growing in a typical gold mining area located in the northeast of Qinghai-Tibet Plateau

Environmental Science and Pollution Research - Though gold mines provide significant economic benefits to local governments, mining causes soil pollution by potentially toxic trace elements (PTEs)...     

Assessing economic sustainability and ecological efficiency with genuine progress indicator: a case study of the Yangtze River Delta from 2000 to 2018

To achieve urban sustainability, it is critical to enhance the environment, economy, and society simultaneously. This study adopted the revised genuine progress indicator (GPI) and ecological footprint (EF) to evaluate the ecological efficiency and economic sustainability of the Yangtze River Delta from 2000 to 2018. Spatial analysis was utilized to identify spatial autocorrelation. A total of 27 cities were then partitioned through k-means cluster analysis. The results showed that GPI and ecological efficiency improved rapidly, but economic sustainability showed a downward trend. GPI and GDP had a high degree of spatial correlation, especially in Suzhou-Wuxi-Changzhou Metropolitan Area. However, no spatial correlation existed between GPI and EF. The city with high GEE can reach 3000 $/gha, indicating the city consumed 1 global hectare to create $3000 of genuine economic growth. Shanghai, Hangzhou, and Taizhou were cities with the highest level of economic sustainability and ecological efficiency. The spatiotemporal characteristics of economic sustainability and ecological efficiency revealed in this study will provide theoretical guidance for alleviating ecological pressure and promoting economic sustainable development.

     

Exploring the embodied carbon flow interactive relationships in China from an ecological network perspective: a model framework and application at provincial level

Environmental Science and Pollution Research - Energy-related carbon emissions take a large proportion in China, and the interregional trade caused by provincial disparities has led to significant...     

一种新型废旧轮胎组合拦石结构的试验研究

提出了一种由废旧轮胎组成的拦石结构,该结构用钢丝绳将废旧轮胎进行合理的绑扎,使轮胎与轮胎之间紧密连接,然后将该结构绑扎在用废旧钢轨或钢筋混凝土制作而成的柱子上面.当拦石结构受到落石冲击时,利用废旧轮胎的弹塑性变形吸收冲击能量.为了考察这种由废旧轮胎组成的拦石结构的防护效果,设计了试验模型,采用20 kg的砝码模拟落石,...     

基于GIS的地震构造信息系统

本文讨论了地震构造信息系统的建造和信息管理。系统是以GIS工具软件ARC/INFO为开发平台建造的,原始资料复盖华北地区的大部,约北纬35～41度,东经109～120度。系统包括活动断裂、破坏性地震、仪器记录地震等信息。本文深入研究了GIS做为信息管理工具的能力,探讨了GIS在地震区划图编制中可能起到的作用。系统能使地震危险分析中信息管理方式、信息管理效率和利用率有质的改进,在某种程度上减小资料利用不充分和人为任意性引起的不确定性。作为一种探索,本文进行了一系列的空间操作和分析,以研究空间特征之间的相关性,并产生新的数据集合。     

循环温度荷载下管式能量桩荷载传递机理研究

基于模型试验方法,开展加热(制冷)工作模式下,实心和管式能量桩的热响应测试研究;分析多次加热/制冷循环作用下两种能量桩的热力耦合特性,实测桩顶位移、桩身应变、以及桩侧摩阻力等变化规律,并对实际运行过程中实心和管式能量桩的承载特性进行初步讨论。研究结果表明,相同直径的管式能量桩换热效率高于实心能量桩,管式能量桩对加热循环的热响应要高于实心能量桩;多次循环后,能量桩桩顶产生塑性沉降、桩身产生微小的塑性应变,桩侧摩阻力值增加。     

不同接种物启动Anammox 反应器的性能研究

采用上流式生物膜滤器(UBF)研究了以厌氧颗粒污泥和反硝化污泥作为接种物启动厌氧氨氧化(Anammox)反应器的性能.结果表明,2 种接种物均能成功启动Anammox 反应器.启动过程可分为菌体自溶阶段、活性迟滞阶段、活性提高阶段和活性稳定阶段.这种启动过程的阶段性特征符合Logistic 方程.以厌氧颗粒污泥启动Anammox 反应器,菌体自溶阶段较长(49d),活性迟滞阶段较短(8d),基质去除速率最高可达2090mg/(L·d);以反硝化污泥启动Anammox 反应器,菌体自溶阶段较短(3d),而活性迟滞阶段较长(36d),基质去除速率最高可达1030mg/(L·d).分别以负荷提升前后的基质去除速率、基质去除率以及出水基质浓度的变化情况作为效能指标评价2 个反应器运行的稳定性,以厌氧颗粒污泥作为接种物启动Anammox 反应器的稳定性能明显占优势.在高负荷率下运行,以反硝化污泥作为接种物启动的Anammox 反应器较易失稳.根据启动过程的阶段性和反应器运行的稳定性,对Anammox 反应器采取相应的调控对策可促进启动过程的顺利进行.     

垃圾填埋场大气汞的浓度和形态

对贵阳市和武汉市的5座城市生活垃圾填埋场大气中的ρ(气态总汞)进行了测定,并分析了填埋场的大气活性气态汞、颗粒态汞、单甲基汞和二甲基汞的质量浓度分布. 结果表明:5座填埋场ρ(气态总汞)为1.6～473.7 ng/m3,不同采样点的平均值为8.5～155.7 ng/m3,最高值出现在填埋场的工作面及工作面下风向区域;而封闭填埋场或运行填埋场的覆土区的ρ(气态总汞)较低. 天气条件和垃圾处理活动均可影响ρ(气态总汞)水平. 贵阳高雁垃圾填埋场大气ρ(活性气态汞),ρ(颗粒态汞),ρ(单甲基汞)和ρ(二甲基汞)的平均值分别为37.4,255.3,12.4和12.7 pg/m3. 虽然不同形态汞的质量浓度明显高于全球背景值,但其产生的环境风险不大.      

重庆市生态足迹时间序列动态特征及其驱动因子分析

生态足迹是近年来广泛用于评价区域发展可持续性的重要方法.基于生态足迹计算模型,利用自然资源和能源消费的统计数据,对重庆市1997-2005年的人均生态足迹序列进行了计算;在此基础上,根据区域社会经济发展与生态足迹变化的作用机理选择了6个社会经济发展相关指标作为自变量,运用主成分回归方法,建立了人均生态足迹的驱动因子分析模型,揭示了驱动生态足迹序列变化的主要因素.计算结果显示,直辖以来,重庆市人均生态足迹总体呈上升趋势,由1997年的1.1244hm2增加到2005年的1.490 3 hm2,而由于耕地占用等原因,人均生态承载力却在逐年减少,从1997年的0.507 5 hm2减少到2005年的0.465 2 hm2,导致该地区人均生态赤字逐年扩大,呈相对不可持续发展状态.驱动力分析模型表明:重庆市社会经济发展对人均生态足迹增长具有强烈的驱动作用.直辖以来,一方面随着工业化、城镇化进程的加快以及消费水平的提升,人均生态足迹也相应同步增长;而另一方面,由于目前的产业和工业结构调整力度有限,因此它们尚未有效发挥降低区域生态足迹的作用.