矿区含氡深井水作饮用水氡污染治理的试验研究

矿区含氡深井水通过实验室小规模除氡试验。结果表明：敞口贮存，曝气和活性炭吸附是除氡的三种有效方法。本文对试验各种过程和结果进行分析讨论。     

UV/Fenton法处理间-甲酚废水

利用UV/Fenton工艺对模拟间-甲苯酚废水进行了处理,研究了H2O2加入量、FeSO4加入量、pH、原水初始COD值、环境温度、反应时间等因素对COD去除率的影响.实验表明：间-甲苯酚浓度为100mg/L、初始COD值251 mg/L的废水,在30℃下,pH为4.Q,[H2O2]/[Fe^2＋]=15（质量浓度比）,紫外灯照射3 h后,COD去除率达86.3%,若再经Ca（OH）2絮凝沉降,则COD去除率提高到92.6%.同时,对Fenton及UV/Fenton的处理效果进行了比较,实验表明：UV/Fenton的处理效果明显优于Fenton法.     

水生植物对淡水生态系统温室气体排放的影响研究进展

淡水生态系统温室气体(CO_2、CH_4、N_2O)排放是全球气候变化背景下的研究热点。水生植物作为淡水生态系统重要的组成部分,对水体生源要素的生物地球化学循环过程具有重要影响,进而影响水体温室气体产生与排放。本研究基于目前水生植物与水体温室气体排放关系的研究,探讨了水生植物对淡水生态系统温室气体排放动力学过程的影响,提出水生植物分布区可能是温室气体排放热点;水生植物种类、生活型的多样性增加了水体温室气体排放的变异性和不确定性,对监测和估算方法的准确性产生一定影响;进一步总结了水生植物对淡水生态系统温室气体排放的影响机制:1)机械作用,包括气体传输通道作用和浮叶植物的滞留作用; 2)水生植物光合/呼吸作用参与水体碳循环,同时水生植物凋落物分解为水体代谢提供新鲜碳、氮源,提高温室气体产生速率; 3)改变根际厌氧环境,影响根际CH_4和N_2O产生与排放; 4)水生植物群落改变水体生态因子分配格局,影响水体异养代谢等。基于当前研究现状,本文提出要进一步开展不同尺度或不同生境条件下水生植物种类、生活型和生长代谢等对水体温室气体排放动力学的影响研究,并从水生植物群落尺度构建温室气体排放动力学模型,优化监测方法与估算模型,为推进我国淡水生态系统温室气体排放研究提供理论基础。     

杭州校园中不同植被对PM2.5的吸附能力

为合理安排绿地配置,极大发挥植物改善生态环境的功能,为城市系统绿化的功能化规范化经济化提供更加合理的理论支持,通过获取杭州电子科技大学校园内现有的4种植被的不同时间段和不同离地高度的ρ（PM_2.5）,用统计学的t检验方法研究了ρ（PM_2.5）的变化规律.以一天当中不同时间空地的ρ（PM_2.5）作为参照,分别对相同时间、不同植被区域、不同高度和不同时间、相同植被区域、相同高度的ρ（PM_2.5）作对比.结果表明:①早晨水杉林、松树林、混合林的PM_2.5吸附能力相似,与空地的平均差值分别为14.36、12.00和12.79 μg/m3;草地的PM_2.5吸附能力较差,与空地的平均差值仅为4.75 μg/m3.中午时,水杉林的PM_2.5吸附能力最强,与空地ρ（PM_2.5）平均差值为10.87 μg/m3,其次为混合林（8.18 μg/m3）,草地ρ（PM_2.5）反而比空地高14.90 μg/m3.下午水杉林与混合林的PM_2.5吸附能力与中午相比略微减弱.晚上,除混合林外,其他3种绿地均与空地无显著差异.②对比距地面0.1与1.5 m高的空气中ρ（PM_2.5）的差异发现,一般情况下树林中0.1 m处ρ（PM_2.5）大于1.5 m处,空地0.1 m处ρ（PM_2.5）小于1.5 m处.研究显示,大部分植被在早晨吸附能力最强、晚上最弱,不同植被对于PM_2.5的吸附能力也有所不同.由此,在所统计的植被中,水杉林对空气中PM_2.5的吸附能力最强,在以后的绿地规划中,可考虑多增加水杉林的种植面积;但在增加城市林地面积减少空气中PM_2.5的同时,还应考虑到植物自身生理能否带来一些城市负面影响,从面得出最优种植方案.      

酒精蒸气/烟草粉尘两相混合体系最小点火能试验研究

在烟草加工的加香工序,挥发的酒精和搅拌混料产生的烟草粉尘形成气粉混合体系,其燃爆特性相较于单相烟草粉尘有较大变化。对20 L爆炸球进行了部分改造,可完成20℃～80℃环境温度、100%LEL以下酒精蒸气浓度、最大2 J电火花能量组合的气粉混合物的最小点火能测试。选用烘丝和加香烟草粉尘做对比,探究了环境温度和酒精蒸气浓度对酒精蒸气/烟草粉尘两相混合体系点火能的影响规律。结果表明：相同环境温度下,加香烟草粉尘的最小点火能比烘丝烟草粉尘低;加香粉尘、烘丝粉尘及混合体系的最小点火能随环境温度变化的趋势一致,均随温度的升高而降低;加入10%LEL的酒精蒸气后,相同温度下气粉混合体系的最小点火能低于单相烟草粉尘。随着环境温度的升高,二者的差值逐渐减小,酒精蒸气诱导烟草粉尘最小点火能降低的能力逐步减小甚至消失;在电点火条件下,当酒精蒸气浓度低于50%LEL时,气粉混合体系较难被点燃,当酒精蒸气浓度高于75%LEL时,混合体系较易被点燃。     

An empirical research on the determinants of Chinese college students’ carbon label cognition and interpersonal communication willingness

Carbon labels are innovative medium and tools for climate change communication and low-carbon marketing. This study aims at examining how college students are aware of low-carbon and carbon labels, whether they are more willing to communicate low-carbon ideas, and also the determinants affecting their interpersonal communication of carbon labels. The multiple regression analysis shows that Chinese college students’ willingness of interpersonal communication of carbon labels are significantly influenced by their awareness of climate change crisis, the perceived value of carbon labels, the consideration of product environmental attributes, the preferences of carbon labels, the household background, and their educational background. In response to these factors, this paper proposes, in a public perspective, the strategies to enhance the dissemination of carbon labels.     

Biodegradation of nicosulfuron by the bacterium Serratia marcescens N80

By enrichment culturing of the sludge collected from the industrial wastewater treatment pond, we isolated a highly efficient nicosulfuron degrading bacterium Serratia marcescens N80. In liquid medium, Serratia marcescens N80 grows using nicosulfuron as the sole nitrogen source, and the optimal temperature, pH values, and inoculation for degradation are 30–35°C, 6.0–7.0, and 3.0% (v/v), respectively. With the initial concentration of 10 mg L^?1, the degradation rate is 93.6% in 96 hours; as the initial concentrations are higher than 10 mg L^?1, the biodegradation rates decrease as the nicosulfuron concentrations increase; when the concentration is 400 mg L^?1, the degradation rate is only 53.1%. Degradation follows the pesticide degradation kinetic equation at concentrations between 5 mg L^?1 and 50 mg L^?1. Identification of the metabolites by the liquid chromatography/mass spectrometry (LC/MS) indicates that the degradation of nicosulfuron is achieved by breaking the sulfonylurea bridge. The strain N80 also degraded some other sulfonylurea herbicides, including ethametsulfuron, tribenuron-methyl, metsulfuron-methyl, chlorimuron-ethyl,and rimsulfuron.     

地铁站火灾人员安全疏散研究综述

为提升地铁站火灾疏散能力,减少灾时人员伤亡和财产损失,国内外大量的研究成果服务于地铁应急预案的制定。分别从研究手段和研究对象方面对国内外近年来的文献进行梳理,分析了地铁站火灾疏散中的烟雾特点、人员应急行为特征和心理反应、疏散中的瓶颈和疏散路径。系统地分析了影响地铁站火灾疏散的因素,比较了不同学者地铁站火灾疏散中存在的差异以及有待改进的地方,从改善地铁设计管理方面和提升人员疏散能力方面提出了建议。     

Leader–member exchange,organizational identification,and knowledge hiding: The moderating role of relative leader–member exchange

In this article, we sought to identify a new interpersonal antecedent of knowledge hiding, namely, leader–member exchange (LMX). Drawing on the group engagement model (an extension of social identity theory within the group/organization context), we built a theoretical model linking LMX and knowledge hiding. This model focuses on the mediating role of organizational identification and the moderating role of relative LMX in influencing the mediation. Using two time‐lagged studies (Study 1: n = 317; Study 2: n = 248) conducted in China, we examined our research model. Study 1 provided support for the proposed hypotheses for evasive hiding and playing dumb but not for rationalized hiding. Study 2 replicated and extended our findings. Results revealed that (a) LMX was negatively related to evasive hiding and playing dumb but not to rationalized hiding; (b) organizational identification mediated the influence of LMX on evasive hiding and playing dumb but not on rationalized hiding; and (c) relative LMX not only moderated the relationship between LMX and organizational identification but also reinforced the indirect effect of LMX on evasive hiding and playing dumb but not on rationalized hiding (via organizational identification). The implications, limitations, and future research directions are also discussed.     

天然次生林人工更新后对土壤物理性质及碳贮量的影响

天然林被人工林取代后对土壤水文物珲性质及土壤碳贮量有重要的影响.文章以海南天然次生林人工更新为尾细桉(Eucalyptus urophylla×E.tereticornis)和马占相思(Acacia mangium)林前后的土壤为研究对象,研究分析了人工植被更新对土壤水文物理性质和土壤碳贮量的影响.结果表明:天然次生林更新为桉树、马占相思人工林后,土壤容重增加,土壤总孔隙度、毛管孔隙度和非毛管孔隙度减小,0～80 cm土壤的最大贮水量、毛管贮水量和非毛管贮水量降低,桉树和马占相思人工林最大贮水量分别降低19.8 mm和43.3mm,桉树人工林0～40cm土壤碳贮量降低6.77t·hm-2,马占相思人工林的增加14.68t·hm-2.