靖江市某电镀集中区典型重金属迁移转化模型参数灵敏性分析

伴随重金属污染风险的不断提高,流域重金属迁移转化模型的构建和水体重金属的模拟预测受到广泛关注,关键参数的甄选是模型优化的重点.本文构建了某电镀集中区Ni、Cu重金属迁移转化数学模型,以Ni为例,采用标准秩回归分析方法(SRRC法)和Sobol多元自适应回归样条算法(Mars-Sobol法)对7个重金属模型参数进行敏感性分析,并针对确定的2个敏感性参数对Ni、Cu模型进行率定和验证.结果表明:1SRRC法的Ni河沙分配系数的敏感性占比为96.1%~99.7%,平均为99.2%,泥沙沉降速率为0.1%~3.3%,平均为0.5%.2Mars-Sobol法的Ni河沙分配系数的总敏感度占比为87.18%~93.44%,平均为90.28%;泥沙沉降速率为5.68%~10.68%,平均为8.21%;随水流运动方向,Ni河沙分配系数敏感性逐渐减低,泥沙沉降速率参数敏感性逐渐增强.3相较于SRRC法,Mars-Sobol考虑了参数间的交互作用,通过Ni、Cu迁移转化模型中敏感参数"河沙分配系数"和"泥沙沉降速率"的率定和验证,Ni、Cu模拟相对误差可控制在15.28%和14.46%,实现了重金属模型的高效和高精度预测.     

Cd胁迫下超富集植物圆锥南芥抗氧化机理

采用土培的方法研究了不同Cd2+添加量(0、10、20、40、80、160、240mg.kg-1)对多金属超富集植物圆锥南芥(Arabis paniculata Franch)抗氧化酶(超氧化物歧化酶SOD、过氧化氢酶POD、抗坏血酸过氧化物酶CAT、过氧化物酶APX)活性、非酶物质(巯基SH、谷胱甘肽GSH、植物络合素PCs)含量以及生物量、叶绿素、丙二醛(MDA)、半胱氨酸(Cysteine)、脯氨酸(Proline)含量的影响.结果表明,随着Cd添加量的增加,圆锥南芥的生物量、Cd含量、富集系数、转运系数呈增加趋势,SOD活性、叶绿素含量呈下降趋势.POD、CAT、APX活性以及MDA含量均呈先升高后降低的变化趋势.圆锥南芥叶片中SH、GSH、PCs含量随Cd添加量的增加而增加,当Cd添加量为240mg.kg-1时,SH、GSH、PCs含量分别比对照提高了92.7%、70.2%、143.4%,表明SH、GSH、PCs在解毒Cd毒害中起着重要作用.     

柳州市社会、经济、资源、环境协调发展评价

运用主成分分析法评价了2000～2006年柳州市社会、经济与资源、环境各子系统的综合发展水平,并通过隶属度函数测算社会、经济、资源、环境各系统间的协调发展状况,找出柳州市可持续发展过程中存在的问题。结果表明：近年来柳州市的社会、经济、资源、环境各系统的综合发展水平不断提高、4个系统间的协调发展状况良好,但柳州市的经济结构还不够合理,经济增长方式仍然较粗放,资源利用率和环境保护工作有待进一步提高。最后提出了相应对策。     

使用变频器、软启动器与缓闭止回阀相结合的办法消除停泵水锤

根据某自来水厂水泵运行中出现的水锤问题,对取水泵房、送水泵房、反冲洗泵房出现的水锤问题进行了分析、试验,针对不同的情况,通过使用变频器、软启动器与缓闭止回阀相结合的办法,减小或消除了停泵水锤。     

A study of farmers' flood perceptions based on the entropy method: an application from Jianghan Plain,China

Using survey data from 280 farmers in Jianghan Plain, China, this paper establishes an evaluation index system for three dimensions of farmers' flood perceptions and then uses the entropy method to estimate their overall flood perception. Farmers' flood perceptions exhibit the following characteristics: (i) their flood‐occurrence, flood‐prevention, and overall flood perceptions gradually increase with age, whereas their flood‐effects perception gradually decreases; (ii) their flood‐occurrence and flood‐effects perceptions gradually increase with a higher level of education, whereas their flood‐prevention perception gradually decreases and their overall flood perception shows nonlinear change; (iii) flood‐occurrence, flood‐effects, and overall flood perceptions are higher among farmers who serve in public offices than among those who do not do so; (iv) the flood‐occurrence, flood‐effects, and overall flood perceptions of farmers who work off‐farm are higher than those of farmers who work solely on‐farm, contrary to the flood‐prevention perception; and (v) the flood‐effects and flood‐prevention perceptions of male farmers are lower than those of female farmers, but the flood‐occurrence and overall flood perceptions of male farmers are higher than those of female farmers.     

太湖真光层深度谱的分布特征及其介质影响探究

基于2010年5月份全湖28个站点分层测量的水体下行辐照度以及各光学介质(有机悬浮物LOI、无机悬浮物ISS、叶绿素a Chl-a)浓度的实测数据,本文运用岭回归分析法,分析了不同湖区5月份真光层深度谱的分布特征及其影响因素.结果表明整个有效光合辐射范围内,3种因素对真光层深度的贡献均为负,ISS浓度是真光层深度的主要贡献因子,贡献率达0.48~0.62;其次为LOI浓度,贡献率为0.34~0.45;Chl-a浓度的贡献最小,贡献率为0.05~0.09.675 nm处,ISS的贡献具有谷值,Chl-a与LOI的贡献却为峰值;520~650 nm处Chl-a贡献值保持低值.此外,按各采样点的真光层深度谱分布的线型向量空间余弦相似度(cosine)进行分步聚类(Ascending Hierarchical),将全湖分为二类,梅梁湾、竺山湾、贡湖湾以及胥口湾以北区域为第一类,其余区域为第二类.结合全湖所有采样点的各介质浓度数据,发现第一类采样点LOI与Chl-a的相对浓度大于第二类,此两类介质浓度凸显了650 nm、675 nm处真光层深度谱分布曲线的波谷特征.     

中国省域能源消费碳排放时空格局演进及驱动机制研究——基于环境规制视角的分析

基于2003—2017年中国不同省域碳排放统计数据,分析中国碳排放时空演进规律,利用中介作用及调节作用检验法,甄别不同能源消费碳排放驱动因素的作用机理并探究省域异质性.结果表明:(1)空间维度上看,中国人均碳排放分布态势呈东部低、中西部高的特征,东部地区人均碳排放变化幅度总体较小,西部地区增速最快.全国人均碳排放呈较为...     

高海拔矿山掘进工作面局部供氧装置研究*

为缓解高海拔矿山掘进作业面低氧问题,将供氧管与环形空气幕相结合,空气幕在作业人员四周形成空气屏障,设计1种用于高海拔矿山掘进工作面的新型供氧装置。以中国云南某海拔3 400 m的铜矿为例,运用ANSYS Fluent软件建立掘进工作面空间模型,根据矿山实际情况确定边界条件,对比研究单一供氧管模式和新型供氧装置的富氧效果差异,并分析空气幕出风口形式、风量对富氧效果的影响。研究结果表明:新型供氧装置的富氧效果优于单一供氧管模式;环状缝隙出风口优于圆孔出风口,并且当环状缝隙宽度为0.010 m、风量为0.014 m3/s时,呼吸带平均氧气质量分数为27.59%,达到最佳富氧效果。新型供氧装置能有效提高作业人员周围呼吸带区域的氧气质量分数。     

Identification of two new cytochrome P450 genes and RNA interference to evaluate their roles in detoxification of commonly used insecticides in Locusta migratoria

Composite samples of Australian farmed Yellowtail Kingfish (Seriola lalandi) (YTKF) (n = 27), Mulloway (Argyrosomus hololepidotus) (n = 6) and manufactured feed (n = 5) were analysed to benchmark levels of a broad range of residues and contaminants of potential public health and trade significance. A subset of these samples [YTKF (n = 5), Mulloway (n = 2) and feed (n = 5)] was analysed for dioxins and polychlorinated biphenyls (PCBs). The mean concentration of dioxins in YTKF was 0.6 pg TEQ g⁻¹ (range 0.22-0.8) and in Mulloway was 0.16 pg TEQ g⁻¹ (range 0.16-0.16). The mean concentration of dioxins and dioxin-like PCBs in YTKF was 2.6 pg TEQ g⁻¹ (range 1.4-3.5), while Mulloway had a mean concentration of 0.67 pg TEQ g⁻¹ (range 0.57-0.76). The mean concentration of PCBs in YTKF was 21 μg kg⁻¹ (range 8.6-29) and in Mulloway was 5.4 μg kg⁻¹ (mean 4.7-6). The mean concentration of dioxin-like PCBs in YTKF was 2.1 pg TEQ g⁻¹ (range 1.2-2.8) and in Mulloway was 0.51 pg TEQ g⁻¹ (range 0.41-0.61). The mean mercury concentration in YTKF was 0.03 mg kg⁻¹ (range 0.02-0.05) and in Mulloway it was 0.02 mg kg⁻¹ (range 0.02-0.04). There were no detectable levels of any pesticide or antimicrobial compounds in any sample of YTKF or Mulloway. Attention is drawn to technical differences in port of entry testing programs such as sampling strategies, portion tested, laboratory methodology, residue definitions and reporting conventions that exporters’ products may be subject to. All residues and contaminants were either undetectable or present at very low levels when judged against Australian, Japanese and European Union regulatory standards (where set).     

Dynamic water quality evaluation based on fuzzy matter–element model and functional data analysis,a case study in Poyang Lake

Environmental Science and Pollution Research - Comprehensively evaluating water quality with a single method alone is challenging because water quality evaluation involves complex, uncertain, and...