Suitable error evaluation criteria selection in the wind energy assessment via the K-means clustering algorithm

In this paper, wind energy potential of four locations in Xinjiang region is assessed. The Weibull distribution as well as the Logistic and the Lognormal distributions are applied to describe the distributions of the wind speed at different heights. In determining the parameters in the Weibull distribution, four intelligent parameter optimization approaches including the differential evolutionary, the particle swarm optimization, and two other approaches derived from these two algorithms and combined advantages of these two approaches are employed. Then the optimal distribution is chosen through the Chi-square error (CSE), the Kolmogorov–Smirnov test error (KSE), and the root mean square error (RMSE) criteria. However, it is found that the variation range of some criteria is quite large, thus these criteria are analyzed and evaluated both from the anomalous values and by the K-means clustering method. Anomaly observation results have shown that the CSE is the first one should be considered to be eliminated from the consequent optimal distribution function selection. This idea is further confirmed by the K-means clustering algorithm, by which the CSE is clustered into a different group with KSE and RMSE. Therefore, only the reserved two error evaluation criteria are utilized to evaluate the wind power potential.     

Decoupling of nonferrous metal consumption from economic growth in China

Nonferrous metal is an important basis material for the development of the national economy, and its consumption directly affects economic development. It has great significance in the effective utilization of nonferrous metals, development of an environment-friendly society, and investigation of the decoupling of nonferrous metal consumption and GDP growth. The decoupling indicators for nonferrous metal consumption and GDP growth (D _r) in China from 1995 to 2010 were calculated in this study, and the results were analyzed. A productive model based on BP neural network was established. Then, the decoupling indicators for nonferrous metal consumption and GDP growth in China for the period of 2011–2020 were predicted. For the period of 1995–2010, the annual average decoupling indicators were <1 for copper, aluminum, zinc, lead, and nickel, except for tin, which was 0.21. The analysis showed that the decoupling of nonferrous metal consumption and GDP growth is in a less optimistic situation to copper, aluminum, zinc, lead, and nickel in China from 1995 to 2010. The annual average decoupling indicator for tin was 0.21, which indicates relative decoupling. For the period of 2011–2020, the predicted decoupling indicators for copper, aluminum, zinc, lead, nickel, and tin were between 0 and 1. This finding indicates the implementation of relative decoupling. However, the total consumption of nonferrous metals did not decouple from GDP growth.     

Toxicity of sediment cores from Yangtze River estuary to zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) embryos

Toxicity evaluation is an important segment in sediment quality monitoring in order to protect aquatic organisms and human health. The purpose of this study is to assess the toxicity of sediments from three sediment cores in Yangtze River Estuary, China, using the zebrafish (Danio rerio) embryo tests. Fertilized zebrafish eggs were exposed to both whole sediments and sediment organic extracts prepared from collected sediments, in order to provide a comprehensive and realistic insight into the bioavailable toxicity potential of the sediments. As end points, development parameters (mortality, hatching rate, and abnormality) in the developing embryos were recorded during the 96-h exposure. The results showed that some samples increased mortality, inhibited the hatching of embryos, and induced morphological abnormalities. The embryonic toxicities presented serrated changes and irregular distribution with depth, which may be related to hydrodynamic effect and unstable environmental input. However, lethal and sub-lethal effects were more significant at the sub-surface sediments (10～40 cm), which indicated that the pollution is more serious in recent decades.     

反硝化条件下有机碳低丰度河床沉积层中的苯胺降解

采集渭河河床沉积物,研究了反硝化条件下有机碳低丰度的河床沉积层中苯胺降解.结果表明,反硝化条件下,苯胺在有机碳低丰度的河床沉积层中可生物降解.使该环境中苯胺(约50 mg/L)降解近95%,当硝酸盐为30.69、184.16、245.54 mg/L时,降解时间分别约为20、45、70 d.在上述环境中另加35.98 mg/L乙酸盐后,苯胺降解速度在硝酸盐为184.16 mg/L时最大,硝酸盐为30.69 mg/L时最小.当硝酸盐为30.69 mg/L,不加乙酸盐,27 d苯胺降解约95%;添加35.98 mg/L乙酸盐后,实验进行了47 d还仍有近13 mg/L苯胺残留,说明外加碳源(乙酸盐)对苯胺降解具有抑制作用.但当硝酸盐为184.16、245.54 mg/L时,外加碳源(乙酸盐)则强化苯胺降解.水合金属氧化物对苯胺降解具有促进作用.     

预处理垃圾焚烧飞灰作为碱胶凝材料混合材的研究

试验分析了垃圾焚烧飞灰的主要化学成分及矿物组成,探讨了预处理垃圾焚烧飞灰作为碱胶凝材料混合材的可能性.研究表明,垃圾焚烧飞灰主要由黏土类矿物组成,飞灰直接作为混合材参与水化过程会产生明显膨胀现象,加入30%(质量分数)飞灰制成的矿渣/飞灰试块在成型1 d脱膜时膨胀率达到15.7%,标准养护28 d后无侧压抗压强度只有12.4 MPa.对飞灰进行热活化预处理,900℃条件下活化效果最佳,同样的飞灰掺量下,试块在标准养护28 d后无侧压抗压强度达到46.0 MPa,膨胀现象消失,且碱胶凝材料中重金属稳定性良好.     

新型树脂对氯酚类物质的吸附研究

合成了乙酰氯修饰树脂NDA-O,与Purolite公司的MN-200相比,合成的树脂比表面积较小,但酸性官能团较多.用两种树脂吸附2-氯酚、4-氯酚和2,4-二氯酚发现,吸附结果可以用Langmuir和Freundlich等温吸附方程很好地模拟,合成的NDA-O对3种氯酚类物质的吸附能力优于MN-200.两种树脂对氯酚类物质的吸附量随着温度的升高而减少,表明吸附是放热过程,同时对氯酚类物质的吸附焓变随着吸附量的增大而减小.对同一种树脂来说,吸附量随着氯代程度的增加而增加,取代氯数相同的时候,吸附量与吸附质的K..成正相关.进一步研究了pH对吸附的影响,在pH大于9时,3种氯酚类物质的吸附量均急剧减少.     

镁砂行业污染治理对策探讨

镁砂行业的污染主要以烟尘、烟气为主。本文针对镁砂行业的治理和管理进行了探索和分析并提出了对策和建议。     

电解-SBR联合技术处理硝基苯废水的试验

采用电解-SBR联合技术对硝基苯生产废水进行降解处理。考察了电流强度、反应时间对有机物去除率的影响,以及电解对废水可生化性的影响。通过试验确定了后续SBR反应器的操作方式和运行参数。结果表明,电解-SBR联合技术对硝基苯废水具有较好的处理效果。