煤与瓦斯突出过程中煤体瓦斯的作用研究

为了研究煤与瓦斯突出过程中煤体瓦斯的作用,采用煤体中瓦斯总量守恒的原理研究瓦斯含量与瓦斯积聚内能的基本方程和影响因素;分析煤与瓦斯突出产生的力学条件和机理,建立了煤与瓦斯突出危险程度的矩阵图。结果表明:瓦斯含量是煤体瓦斯内能最直接的反应,其值大小决定瓦斯内能的大小;瓦斯压力梯度、煤体的断裂韧性及煤体内的裂隙发育程度决定着瓦斯突出的危险性,低渗透性构造煤对瓦斯运移阻力较大,容易形成较大的瓦斯压力梯度,从而更容易发生煤与瓦斯突出。煤层中的瓦斯含量、瓦斯压力、地应力越大,煤体的强度、渗透率越小,越容易发生突出。煤层瓦斯情况、力学性能、地质构造和煤层的应力状态是决定煤与瓦斯突出的主要因素。     

UBF反应池爆炸后混凝土结构安全检测及加固处理研究

检测和评估了UBF反应池爆炸后结构的现状,包括了外观情况检测、混凝土强度测试以及池壁混凝土内部缺陷检测。在保证结构安全的前提下,提出经济合理的加固处理方案。     

Agricultural Lakes in Finland: Current Water Quality and Trends

Agriculture is the largest source of nutrients into surface waters in Finland, and yet relatively little is known about the actual impact of the agricultural load on the state of lakes. We analysed the water quality data of 20 Finnish agricultural lakes and found that they had higher levels of nutrients, chlorophyll a and turbidity than did the other types of lakes (e.g. those receiving point-source load) in the national monitoring network (the Finnish Eurowaternet). Currently, six of the agricultural lakes can be classified as eutrophic and 14 as hypertrophic. Trend analysis (based on Kendall's tau-b) indicated that during 1976–2002 the water quality of the lakes either remained constant or showed signs of increasing eutrophication and elevated turbidity. Decreasing nutrient concentrations were found only in one intensively restored lake. In none of the lakes had the chlorophyll a concentration decreased. The results of the trend analysis are compatible with the recent finding that, despite vigorous efforts, the nutrient load from agriculture has not declined in Finland. Recovery of the most eutrophied agricultural lakes would call for a drastic reduction in the external nutrient load, possibly supplemented with in-lake restoration.     

First Step for an Ecological Risk Assessment to Evaluate the Impact of Diffuse Pollution in Lake Vela (Portugal)

Lake Vela, located in the Portuguese littoral-centre, is a temperate shallow lake exhibiting a high trophic status. This aquatic ecosystem has been potentially exposed to contamination generated by agricultural and livestock activities held in their drainage basin, which seriously compromise their health. This work summarizes some background information and presents the problem formulation step of the ERA. Therefore, it evaluates the characteristics of the stressor(s), describes the ecological system and receptors and suggests a conceptual model, which predicts the potential exposure pathways, relating suspected sources to the defined endpoints. This introductory step also described an analysis plan on the entire study, which includes a delineation of the assessment design, data needs, measures, and methods for conducting the analysis phase of the risk assessment process.     

内电解预处理酵母工业废水研究

酵母工业废水属于高浓度、高色度、难降解有机废水,如果不进行有效处理,将会对环境造成较大污染。研究了以铁屑和活性炭为原料的内电解方式处理酵母废水,对影响内电解效果的主要因素进行了试验,确定了反应条件。在确定条件下试验,内电解对色度、COD的去除有一定的效果,重要的是提高了废水的可生化性,有利于生物处理。     

基于MODIS的西藏典型湖泊叶绿素a浓度反演

叶绿素a浓度是反映湖泊富营养化状态的一个重要参数。以MODIS L1B数据为基础，结合叶绿素a浓度实测数据，基于经验分析法实现了西藏典型湖泊叶绿素a浓度反演研究，并探索了西藏典型湖泊2019年春、夏、秋季叶绿素a浓度的时空变化特征。首先，利用叶绿素a浓度实测数据和MODIS L1B影像不同波段的反射率值进行组合试验，选择最佳波段组合建立模型；其次，分别选用2015年、2017年叶绿素a浓度实测值和反演值对模型进行对比验证；最后，利用叶绿素a浓度反演模型对西藏典型湖泊2019年春、夏、秋季叶绿素a浓度的时空变化特征进行分析。结果表明：在空间尺度上，西藏典型湖泊叶绿素a浓度整体上呈现出周围高、中部低的分布特征，且湖岸水体叶绿素a浓度变化较大；在季节尺度上，不同湖泊叶绿素a浓度的季节变化存在较大差异，格仁错和色林错的季节变化幅度较大，纳木错、塔若错和羊卓雍错的季节变化幅度较小。     

山水林田湖草生态保护修复江苏实践与思考

“实施山水林田湖草生态保护和修复工程，全面提升自然生态系统稳定性和生态服务功能”是习近平生态文明思想的重要创新成果，为开展生态环境保护修复工作提供了重要指引和根本遵循。2019年以来，江苏省开展山水林田湖草生态保护修复省级试点工程共5类59个工程项目。在总结了试点地区工作经验做法的基础上，针对存在的生态保护修复和绿色发展协同理念认识不足、生态修复保护整体性和系统性不够、生态修复经验总结及全周期管理有待加强、打破界限的体制机制改革创新亟需完善等问题及难点，提出了相应的工作政策建议，以期打造全国生态保护修复的江苏样板。     

Short- and long-term patterns of ¹³⁷Cs in fish and other aquatic organisms of small forest lakes in southern Finland since the Chernobyl accident

We summarize the patterns of ¹³⁷Cs activity concentrations and transfer into fish and other biota in four small forest lakes in southern Finland during a twenty-year period following the Chernobyl accident in April 1986. The results from summer 1986 showed fastest accumulation of ¹³⁷Cs into planktivorous fishes, i.e. along the shortest food chains. Since 1987, the highest annual mean values of ¹³⁷Cs have been recorded in fish occupying the highest trophic levels, for perch (Perca fluviatilis) 13,600 Bq/kg (ww) and for pike (Esox lucius) 20,700 Bq/kg (ww). At the same time, activity concentrations of ¹³⁷Cs in crustacean zooplankton and Asellus aquaticus have ranged between 1000 and 19,500 Bq/kg (dw). In 2006, 5-28% of the 1987 ¹³⁷Cs activity concentration levels were still present in perch and pike. Since 1989 their ¹³⁷Cs activity concentrations in oligohumic seepage lakes have remained significantly higher than in polyhumic drainage lakes due to the increased transfer of ¹³⁷Cs into fish in the seepage lakes with lower electrolyte concentrations, longer water retention times and lower sedimentation rate.