江苏太湖地区农业耕作制度变化及其对地表水土环境的影响

农业耕作制度变化及其环境效应是国内外广泛关注的学术前沿问题。近60 a来,江苏太湖地区农业耕作制度发生较大变化,主要表现在种植制度从偏重粮食生产转向粮经作物协调发展,用地作物增多而养地作物减少,作物品种经历了改进与优化过程,作物熟制经历了从“双三制”恢复到两熟制。施肥种类从有机肥为主转变为完全施用化肥,氮磷钾肥投入比例从长期严重失调发展到逐渐趋于协调。在总结近60 a来江苏太湖地区农业耕作制度变化特征的基础上,〖JP2〗分析了农业耕作制度变化对地表水土环境的影响,并提出了今后需要进一步关注的研究方向     

Corrosion control when using passively treated abandoned mine drainage as alternative makeup water for cooling systems

Passively treated abandoned mine drainage (AMD) is a promising alternative to fresh water as power plant cooling water system makeup water in mining regions where such water is abundant. Passive treatment and reuse of AMD can avoid the contamination of surface water caused by discharge of abandoned mine water, which typically is acidic and contains high concentrations of metals, especially iron. The purpose of this study was to evaluate the feasibility of reusing passively treated AMD in cooling systems with respect to corrosion control through laboratory experiments and pilot-scale field testing. The results showed that, with the addition of the inhibitor mixture orthophosphate and tolyltriazole, mild steel and copper corrosion rates were reduced to acceptable levels (< 0.127 mm/y and < 0.0076 mm/y, respectively). Aluminum had pitting corrosion problems in every condition tested, while cupronickel showed that, even in the absence of any inhibitor and in the presence of the biocide monochloramine, its corrosion rate was still very low (0.018 mm/y).     

典型石化废水达标排放处理技术综合评估

构建了基于层次分析法（AHP）和标杆法（BM）的水污染控制技术混合评估模型,并以石化废水达标排放处理技术为例,确定了包含3项一级指标、8项二级指标和14项三级指标的评估指标体系和指标权重。以5种典型石化废水达标排放处理技术工艺为评估对象,获得技术、经济、环境单项评估指数和综合评估指数。评估结果表明,“隔油+气浮+A/O-PACT”和“隔油+气浮+MBBR+催化臭氧氧化+BAF”两种技术工艺综合指数较高。实际应用时,还应根据工程实际情况对指标权重进行调整,因地制宜地选择合适的废水达标排放处理技术工艺。     

On a combined theory of pay level satisfaction

For decades, research on pay level satisfaction has focused on two theories and one approach: the direct link theory, the discrepancy theory, and the no‐difference‐scores approach. However, there are still unsolved puzzles facing pay level satisfaction research. We develop a combined theory to consider the impact of the interaction of reported pay and pay discrepancy. With this newly developed theory, we expect that (a) both reported pay and pay discrepancy have main effects on pay level satisfaction; (b) reported pay and pay discrepancy also interact with each other, in that the effect of pay discrepancy on pay level satisfaction decreases as pay level increases; (c) equitable payment is more related to pay level dissatisfaction when pay level is low; and (d) overpayment in general is related to pay level satisfaction, not dissatisfaction. An empirical study (N = 481) using four types of comparison standards was conducted, and the results supported our predictions. The findings of our study have important implications for both academic research and management practice.     

基于模拟土壤含水量的长江上游#br# 干旱事件时空特征分析

干旱灾害是对我国农业生产和生态环境影响最为严重的自然灾害之一,研究干旱的时空变化特征对干旱的评估、预测有重要的指导意义。研究基于VIC（Variable Infiltration Capacity）模型模拟的50km分辨率的逐日土壤含水量数据,计算土壤含水量距平指数（SMAPI）并分析了长江流域上游1953~2013年历史干旱事件的时空变化特征。结果表明：（1）VIC模型能较好的模拟出1980~2000年长江流域上游出口宜昌断面的流量过程;（2）SMAPI指数能够反映长江流域上游实际干旱的发生、发展过程和严重程度,能够较好地再现历史干旱情形;（3）通过研究长江流域上游的干旱历时 面积 强度关系发现,干旱历时一定时,随着干旱面积的增加,干旱强度总体呈增强的趋势。研究结果对于深入认识长江流域上游历史干旱长期演变特征和增强区域防旱抗旱能力具有一定的理论和实用价值。 关键词： VIC模型;土壤含水量距平指数;时空特征;长江上游     

水喷淋对仓库火蔓延及烟气输运影响的数值模拟

以某仓库作为工程背景,采用多维数值模拟研究水喷淋对火灾火蔓延及烟气输运的作用和影响。分别对该仓库在无水喷淋、水喷淋及时启动以及水喷淋延时动作的三种情况进行了较为详细的计算。模拟结果表明,无水喷雾时,该仓库的火蔓延速度逐步加快,热烟气层从顶棚附近逐步下降到地面附近;水喷雾及时启动时,火蔓延被有效抑制,热烟气层仅停留在顶棚附近;水喷淋延时动作时,火已经蔓延到较大区域,货物处于高温区,热烟气层下降到地面附近,虽然火被水喷淋系统扑灭,但货物已受到高温和烟气的危害。模拟结果为同类型仓库设计水喷淋系统的必要性提供了科学依据,同时也论证了确保水喷淋系统完整好用的重要性。     

浅谈循环经济与畜禽粪便资源化对策

畜禽养殖业的蓬勃发展,改善了农业生产结构,促进农村经济水平的提高,但是废弃物又造成了环境污染.运用循环经济理论指导畜禽粪便污染环境的治理并使其资源化,在减少生态环境污染的同时,又提高了资源的利用效率,具有很大的经济效益和生态效益.本文通过分析畜禽粪便对环境的危害及其资源特性,提出了资源化、无害化的途径.     

Adsorption of arsenic(V) onto fly ash: a speciation-based approach

Arsenic (As) poses a significant water quality problem and challenge for the environmental engineers and scientists in the world. The large volume of coal fly ash produced around the world is a potentially significant anthropogenic source of arsenic. Currently the leaching behavior of arsenic from fly ash is not well understood. Batch methods were used in this study to investigate arsenic leaching using a raw ash, and arsenic adsorption using a clean, washed ash. Experimental results indicated that pH had a significant effect on arsenic leaching or adsorption. Between pH 3 and 7, less arsenic was in the dissolved phase. When pH was less than 3 or greater than 7, increasing amounts of arsenic were leached or desorbed from fly ash. The leaching and adsorption behavior of arsenic was interpreted with the speciation of surface sites and arsenic. In a new approach, a speciation-based model was developed to quantify the arsenic adsorption as a function of pH and surface acidity parameters. This work is important in offering insight into the leaching mechanism of arsenic from coal fly ash, and providing a robust model based upon specific, measurable parameters to quantify arsenic adsorption by other solid media in addition to fly ash.     

苏州市初夏臭氧污染成因及年际变化

以2017~2021年的5~6月苏州市城区站点的大气污染物浓度为研究对象,分析了臭氧（O₃）、氮氧化物（NO_x）、总氧化剂（O_x）、一氧化碳（CO）和挥发性有机物（VOCs）等污染物的变化特征,利用基于观测的模型（OBM）研究了O₃污染成因及其年际变化,解析了环境空气VOCs的主要来源及其变化趋势.结果表明：①近年来苏州O_x平均体积分数以及NO_x和CO平均浓度整体呈下降趋势,但VOCs的体积分数整体呈上升趋势;O₃污染天光化学反应前体物浓度水平仍较高,且显著高于优良天.②近年来苏州O₃生成处于VOCs控制区;苏州市VOCs和NO_x长期减排比例应不低于5∶1,在VOCs控制方面应注重对芳香烃和烯烃的减排.③源解析结果显示,工业排放、汽油车尾气和柴油机尾气是苏州市VOCs的主要排放源;近年来工业排放源和溶剂使用源有所下降,但汽油车尾气源和油气挥发源贡献率上升明显,且上述两类污染源排放VOCs的O₃生成潜势较高.④综合分析各排放源对O₃生成潜势的贡献发现,溶剂使用源和汽油车尾气源的VOCs排放是影响苏州市O₃生成的关键因素.     

餐饮业油烟污染及治理技术浅议

餐饮业油烟污染空气 ,影响人体健康 ,应引起高度重视。治理技术设备主要有静电法、过滤法和洗涤法等方法 ,各种设备各有其优点和缺点 ,要不断创新完善 ,尽快使餐饮业油烟达标排放