Profile of Methane Concentrations in Soil and Atmosphere in Alpine Steppe Ecosystem on Tibetan Plateau

The methane concentration profile from -1.5m depth in soil to 32m height in air was measured in alpine steppe located in the permafrost area. Methane concentrations showed widely variations both in air and in soil during the study period. The mean concentrations in atmosphere were all higher than those in soil, and the highest methane concentration was found in air at the height of 16m with the lowest concentration occurring at the depth of 1.5m in soil. The variations of atmospheric methane concentrations did not show any clear pattern both temporally and spatially, although they exhibited a more steadystable state than those in soil. During the seasonal variations, the methane concentrations at different depths in soil were significantly correlated （R^2〉0.6） with each other comparing to the weak correlations （R^2〈0.2） between the atmospheric concentra- tions at different heights. Mean methane concentrations in soil significantly decreased with depth. This was the compositive influence of the decreasing production rates and the increasing methane oxidation rates, which was caused by the descent soil moisture with depth. Although the methane concentrations at all depths varied widely during the growing season, they showed very distinct temporal variations in the non-growing season. It was indicated from the literatures that methane oxidation rates were positively correlated with soil temperature. The higher methane concentrations in soil during the winter were determined by the lower methane oxidation rates with decreasing soil temperatures, whereas methane production rates had no reaction to the lower temperature. Relations between methane contribution and other environmental factors were not discussed in this paper for lacking of data, which impulse us to carry out further and more detailed studies in this unique area.     

大型相连容器中火焰传播的研究

为了进一步了解相连装置中粉尘爆炸的火焰传播行为和压力发展,为该结构的安全防护设计提供有价值的信息,采用大型实验装置对相连容器中玉米淀粉/空气混合物爆炸时的火焰传播行为进行了实验研究,同时采用已开发的数值模型对实验进行仿真计算。实验表明:粉尘浓度的变化对粉尘爆炸的火焰传播行为有重要影响;在粉尘浓度很低的情况下,火焰仍然能够在管道中加速传播且爆炸发展的最终结果相当猛烈。数值模型采用欧拉-拉格朗日方法模拟两相流现象,通过求解非稳态的湍流两相反应流守恒方程对实验进行二维仿真,计算结果与实验结果符合性较好,表明该模型可以很好地应用于粉尘爆炸火焰传播的研究。     

2，2‘,4,4’和3，3‘,4,4’—四氯联苯（TCB）对小白鼠体外受精的影响

采用体外受精技术评价环境污染物2,2',4,4'-和3,3',4,4'-四氯联苯对小白鼠卵母细胞受精能力和2-细胞胚胎发育的毒性作用,实验结果表明：ρ（PCB）=0.1,1.0,10.0mg/mL的2,2',4,4'-和3,3',4,4'-四氯联苯均显著降低小白鼠卵母细胞的受精能力;ρ（PCB）=1.0,10.0mg/mL的2,2',4,4'-和3,3',4,4'-四氯联苯使卵母细胞的退人弦和2-细胞的畸形率显著增加;两种四氯联苯对小白鼠卵母细胞体外受精能力、退化率和2-细胞胚胎的畸形率无统计差异。     

2,2’,4,4’-和3,3’,4,4’-四氯联苯(TCB)对小白鼠体外受精的影响(英文)

采用体外受精技术评价环境污染物 2 ,2’ ,4,4’ 和 3,3’ ,4,4’ 四氯联苯对小白鼠卵母细胞受精能力和 2 细胞胚胎发育的毒性作用 .实验结果表明 :ρ(PCB) =0 .1,1.0 ,10 .0mg/mL的 2 ,2’ ,4,4’ 和 3,3’ ,4,4’ 四氯联苯均显著降低小白鼠卵母细胞的受精能力 ;ρ(PCB) =1.0 ,10 .0mg/mL的 2 ,2’ ,4,4’ 和 3,3’ ,4,4’ 四氯联苯使卵母细胞的退化率和 2 细胞的畸形率显著增加 ;两种四氯联苯对小白鼠卵母细胞体外受精能力、退化率和 2 细胞胚胎的畸形率无统计差异 .表 2参 2 5     

南部非洲的一体化电力计划

本文概括了12个南部非洲国家电力联营的一体化电力计划(IEP)过程,阐述了使用IEP的长期计划,本文同时也着重讨论了关于未来生产量的决策过程,提出了有利于在南非采纳更清洁技术的角色和措施.     

牛骨炭对水溶液中Hg（Ⅱ）吸附性的研究

以牛骨为原料,氯化锌为活化剂制备牛骨基炭,通过静态吸附试验研究了牛骨炭对水中Hg（Ⅱ）的吸附效果并确定了影响吸附性能的因素。研究结果表明：牛骨炭对Hg（Ⅱ）的最佳吸附时间约为2h、吸附温度为25℃、pH值为1、投加量为0．1g、吸附溶液的最大初始浓度为600mg／L,其最大吸附容量Q^0为43．1mg／g,吸附行为符合Freundl—ich吸附等温模型;通过BET分析和扫描电镜（SEM）等手段表征了牛骨炭的孔结构参数及形貌特征,经分析,所制备牛骨炭的孔径分布为中孔。     

上海市生态资产核算体系研究

自然资源资产是具有商业或交换价值的自然环境要素,是人类生存与发展的基础。生态资产是自然资源资产的重要组成部分,提供各种产品和服务。以生态资产为研究对象,从存量和流量两个方面构建核算体系,并以上海市为案例,探讨了生态资产核算体系的核算方法,评价了上海市2013年的生态资产状况与价值总量。结果显示,存量核算方面,林地的质量等级主要为中,占林地总面积的45.62%;河流的质量等级主要为劣,占总长度的54.65%。2013年生态资产流量总价值量为5 002.76亿元,其中,直接产品价值为866.12亿元,间接服务价值为4 136.64亿元。结果表明,生态资产核算体系体现了生态资产对区域社会经济发展的支撑作用,可以用来定量评估和核算区域的生态资产状况及其变化特征,可以为区域的生态系统管理与绩效考核提供科学依据。     

芘高效降解菌ZQ_5的培养条件及无机元素对其降解效率的影响

以从我国最大的石油污水灌区之一——沈抚灌区污染土壤分离到的以芘为惟一碳源、能源生长的高效降解菌株ZQ5为实验材料,通过对菌株ZQ5培养条件的优化,以及采用摇瓶振荡培养方法测定菌株ZQ5对不同浓度芘的降解率,表明：菌株ZQ5在30℃振荡培养16 d后对150 mg/L芘的降解率为90.31%。通过模拟稻田施用N、P和K肥等的土壤环境,探索了无机营养元素对降解菌ZQ5降解能力的影响,发现土壤中混合加入N、P和K无机营养元素的降解率能达到82%以上,比单加某种营养元素对降解菌ZQ5的降解效果好。本研究结果可以指导稻田PAHs的原位生物修复。     

New Development in Study of the Faustmann Optimal Forest Harvesting

Chinese forest resources have become very scarce in the face of rapid economic growth demand, while the reform of collective forest right system is in full swing across the country. It will directly affect the regeneration level of forest resources and the diverse ecological value functions. In this article, the mainstream model paradigm of forest economics, that is, the basic framework of the Faustmann model and its evolution process are made in a more detailed explanation, especially the extended model in...     

Do DBPs swim in salt water pools? Comparison of 60 DBPs formed by electrochemically generated chlorine vs. conventional chlorine

Disinfectants are added to swimming pools to kill harmful pathogens. Although liquid chlorine(sodium hypochlorite) is the most commonly used disinfectant, alternative disinfection techniques like electrochemically generated mixed oxidants or electrochemically generated chlorine, often referred to as salt water pools, are growing in popularity. However, these disinfectants react with natural organic matter and anthropogenic contaminants introduced to the pool water by swimmers to form disinfectio...