应用物种敏感性分布法分析太湖及天目湖水体的生态风险

采用物种敏感性分布法(SSDs法),应用水生生物急性和慢性毒性数据计算了31种污染物在水中和其中疏水物质在沉积物中的预测无效应浓度(PNECwater和PNECsed),通过收集以往报道的16种污染物在太湖和天目湖的环境浓度,用商值法求得物质的风险商并进行排序.结果发现:蒽、菲、萘、荧蒽、阿特拉津和马拉硫磷在太湖的梅梁湾和五里湖具有很大的生态风险;毒死蜱、三丁基锡氧化物和环己锡虽无环境浓度报道但很有可能具有风险.     

Evaluation of potential responses to invasive non-native species with structured decision making

In managing invasions and colonizations of non-native species, eradication or control efforts must proceed quickly. There are 2 challenges in taking such quick action. First, managers frequently have to choose among complex and often competing environmental, social, and economic objectives. Second, the effects are highly uncertain. We applied participatory structured decision making (SDM) to develop a response plan for the recent invasion of non-native myrtle rust (Uredo rangelii) in Australia. Structured decision making breaks a complex decision process into 5 steps: identify problems (i.e., decisions to be made), formulate objectives, develop management alternatives, estimate consequences of implementing those alternatives, and select preferred alternatives by evaluating trade-offs among alternatives. To determine the preferred mid- to long-term alternatives to managing the rust, we conducted 2 participatory workshops and 18 interviews with individuals to elicit stakeholders' key concerns and convert them into 5 objectives (minimize management cost, minimize economic cost to industry, minimize effects on natural ecosystems and landscape amenities, and minimize environmental effects associated with use of fungicide) and to identify the 5 management alternatives (full eradication, partial eradication, slow spread, live with it [i.e., major effort invested in mitigation of effects], and do nothing). We also developed decision trees to graphically represent the essence of the decision by displaying the relations between uncertainties and decision points. In the short term or before local expansion of myrtle rust, the do-nothing alternative was not preferred, but an eradication alternative was only recommended if the probability of eradication exceeded about 40%. After the expansion of myrtle rust, the slow-the-spread alternative was preferred regardless of which of the short-term management alternatives was selected at an earlier stage. The participatory SDM approach effectively resulted in informed and transparent response plans that incorporated multiple objectives in decision-making processes under high uncertainty.     

基于模糊层次综合评判法的集气站安全评价

集气站是天然气集输系统的重要组成部分,其安全性和稳定性是保证天然气输送的前提。根据气田集气站的现场生产实际情况,从人员-环境-管理-设备及管线4个方面构建集气站安全评价指标体系,应用模糊层次综合评判法建立4级模糊综合评判模型,对集气站的本质安全生产状况进行评价。基于此方法开发了"采气厂区域安全评估系统"软件,通过该软件计算集气站本质安全程度,并根据评价结果提出相应的整改和建议措施。将软件应用于苏里格气田第五采气厂。结果表明,将模糊层次综合评判法作为集气站安全评价方法是实用有效的。     

基于BP神经网络的煤与瓦斯突出预测系统开发

煤与瓦斯突出影响因素多,难以为其建立合适的多指标非线性预测模型,为提高突出预测的准确性和增强预测预报方法的实用性,采用改进的BP算法建立煤与瓦斯突出预测数学模型。通过研究不同算法的突出预测效果,对已建模型的泛化能力进行检验,利用Matlab GUI和神经网络工具箱设计开发煤与瓦斯突出预测系统,通过向系统输入已知的突出样本数据,经过学习、训练,实现对未知参数的预测。仿真结果表明:网络在训练300次后,误差训练曲线的均方差(MSE)可以达到10-15,实际预测误差也小于0.1,系统得到的5组数据预测结果与实际情况相符。     

Co- or Ni-modified Sn-MnOx low-dimensional multi-oxides for high-efficient NH3-SCR De-NOx: Performance optimization and reaction mechanism

NH₃-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method.Due to its strong oxidation performance,Sn-MnOx was prone to side reactions between NO,NH₃ and O₂,resulting in the generation of more NO₂ and N₂ O,here most of N₂ O was driven from the non-selective oxidation of NH₃,while ...     

High cadmium adsorption on nanoscale zero-valent iron coated Eichhornia crassipes biochar

Environmental Chemistry Letters - Overgrowth of Eichhornia crassipes, or water hyacinth, in local waters is a major concern, which has caused severe ecological disasters. Moreover, once the E....     

宁夏光伏电站模型参数对电网安全稳定性的影响

通过开展光伏电站的等值建模、参数辨识、模型评价的体系研究,为宁夏电网开展光伏电站模型参数测试业务提供完备的技术储备,为包含光伏发电的宁夏电网安全稳定分析和运行控制提供了基础模型和数据支撑,可广泛应用于方式计算、运行规划、事故分析及反措制定等方面,具有广阔的推广应用前景和实用价值。     

从组分和性质角度谈污染地块中石油烃的人体健康风险评估

石油烃的人体健康风险评估是污染地块土壤污染风险评估过程中的最常见的问题之一,其远比单一污染物的评估复杂和困难.但我国缺乏针对性的评估方法,实际操作中存在较多误区.因此,对于石油烃概念、性质的归纳总结以及对其健康风险评估方法的研究和探索,具有重要的意义.本文介绍了石油烃的基本概念,分析了不同馏分性质间的关系,回顾并分析了其分析测试方法及人体健康风险评估方法的适用要求及优缺点,提出了指示剂法与分馏法相结合采用典型样品馏分占比进行总体评估的工作方法,进而针对我国当前面临的问题,提出了后续的研究和发展建议.     

Mapping loci that control lateral spike development in Tibetan barley by bulked segregant analysis (BSA)北大核心CSCD

Fertility of lateral spikelets determines the two-rowed or six-rowed spikes of barley (Hordeum vulgare L.), which results in significantly different grain yields. The change in row type from two-rowed to six-rowed shows remarkable domestication characteristics. The Qinghai-Tibet plateau has abundant resources of wild and cultivated barley, and is considered one of the centers of domestication and genetic diversity of cultivated barley. In order to obtain a primary understanding of the genetic basis of lateral spike development regulation and the domestication process in cultivated Tibetan barley, an F2 segregation population was constructed by crossing the two-rowed wild barley accession ZYM0083 with the six-rowed landraces Linzhiheiliuleng. Genetic analysis showed that the row type was controlled by a single gene. Using the specific-locus amplified fragment sequencing (SLAF-seq) technology and bulked segregant analysis (BSA), two DNA pools from 22 two-rowed spike individuals and 22 six-rowed spike individuals of the F2 population were constructed and sequenced. A total of 456 691 SLAF tags were obtained. By adopting the ED and SNP index for association analysis, three candidate regions with a 53.84-Mb interval and containing 536 genes were obtained. Four-hundred thirteen, 189, and 160 annotated genes were acquired by GO, KEGG, and COG libraries, respectively. Loci that control lateral spike development in Tibetan barley were primarily mapped by SLAF-seq, and the results presented in this study will facilitate the fine mapping and cloning of target genes. © 2018 Science Press. All rights reserved.     

Efficient metoprolol degradation by heterogeneous copper ferrite/sulfite reaction

Metal/sulfite systems are currently used for SO ₄ ^?? generation and oxidative removal of organic contaminants. However, homogeneous metal/sulfite systems are limited because their working pHs must be acidic and metal ions cannot be separated from the bulk reaction solution. As a consequence, these drawbacks have severely limited the application of metal/sulfite systems in real conditions. To address these issues, we tested the use of copper ferrite (CuFe₂O₄), a ferromagnetic nanoparticle, to catalyze sulfite oxidation for the degradation of the metoprolol drug. The reaction mechanism was investigated by electron spin resonance, X-ray photoelectron spectroscopy, and radical quenching assay. The effects of pH, CuFe₂O₄, and sulfite dosages were also assessed. Results show that SO ₄ ^?? was the primary radical responsible for metoprolol degradation. Higher pHs induced more metoprolol degradation using CuFe₂O₄/sulfite. Moreover, CuFe₂O₄ remained morphologically intact and catalytically active after four batches of recycling. Overall, our findings show that CuFe₂O₄/sulfite can effectively degrade water contaminants in alkali pH and withhold catalyst activity after multiple reuses, therefore addressing the issues associated with homogeneous metal/sulfite systems.