不同含水率煤尘在瓦斯爆炸诱导下爆炸传播规律研究

为了探究不同含水率煤尘在瓦斯爆炸诱导下的爆炸传播规律,利用自行搭建的直管瓦斯爆炸诱导煤尘二次爆炸实验系统,从冲击波压力和火焰传播速度2个方面,研究了不同含水率沉积煤尘在瓦斯爆炸诱导下的爆炸传播规律和原因。研究结果表明:当煤尘含水率小于40%时,管道内沉积煤尘会在瓦斯爆炸诱导下产生二次爆炸,同时沉积煤尘总量一定时,沉积煤尘二次爆炸产生的冲击波超压峰值和火焰传播速度随着煤尘含水率的增加先增大后减小;当沉积煤尘含水率为20% 时,煤尘二次爆炸产生的冲击波超压峰值、火焰传播速度峰值达到最大值,分别为1.657 MPa和468.060 m/s;当沉积煤尘含水率大于40%时,沉积煤尘无法产生二次爆炸,此时爆炸产生的威力小于单一瓦斯爆炸,火焰传播速度衰减较无煤尘的瓦斯爆炸更快,沉积煤尘起到抑制瓦斯爆炸传播的作用。研究结果可以为防治煤尘二次爆炸提供理论依据。     

利用碎片常数和结构因子法估测农药在正辛醇／水相中的分配系数

本文详细阐述了用碎片常数与结构因子法估测农药在正辛醇与水相体系中分配系数的方法，并对６０种农药分配系数的估测结果与用经典的摇瓶测试法得到的实测值进行了比较，结果表明：估测结果与实测值基本吻合，碎片常数和结构因子估测法可以作为获得农药分配系数的另一种途径。     

农药和其它有机化合物环境参数的相关性及其预测

农药和其它有机化合物的水溶解度、正辛醇／水分配系数、有机碳吸附常数和生物浓缩因子等物化参数之间存在着明显的相关性，有机化合物的水溶解度与其正辛醇／水分配系数、有机碳吸附常数和生物浓缩因子呈负相关；正辛醇／水分配系数与有机碳吸附常数和生物浓缩因子呈正相关。本文所建立的数学关系式能较好地预测未知化合物的环境特性。     

The development of first-possession rules in US mining, 1872–1920: theory, evidence, and policy implications

This paper applies a property rights framework to federal mineral lands in the western United States from the enactment of the Mining Law in 1872 until the enactment of the Mineral Leasing Act for fossil fuels in 1920. There are two principal findings. First, the Mining Law appears to have been an effective means for assigning rights to mineral stocks on public lands (at least through 1920). This conclusion is supported by evidence from claim disputes in the West. Second, the impetus for the Mineral Leasing Act did not derive from the different physical characteristics of hardrock minerals and petroleum. The relevance of these conclusions to contemporary mineral policy is also discussed.     

浅论对《中华人民共和国环境影响评价法》的认识

《中华人民共和国环境影响评价法》的颁布改变了我国从1979年以来实施的建设项目环境影响评价制度中的一些缺陷与不足，提高了环境影响评价工作的法律地位，有利于环境影响评价工作的公平、公正和公开进行。但同时由于各方面条件的限制，这部法律也留下了一些值得商榷的地方。本文结合赤峰地区环境影响评价工作出现的问题，浅论环境影响评价领域的进步与遗憾，并提出一些建议。     

海南三亚近岸海域水化学要素的分布特征和变化规律

本文调查研究了海南三亚近岸海域水化学要素的浓度和分布，结果表明：（１）表层ＤＯ、ＮＯ－２、ＮＯ－３、ＮＨ＋４、ＰＯ３－４和ＣＯＤ的平均浓度分别为４１１．９、０．０５、０．４７、１．７９、０．１６μｍｏｌ／ｄｍ３和１．３１ｍｇ／Ｌ。（２）河流输入对沿岸海域水化学要素的影响主要集中于ＮＨ＋４和ＣＯＤ，对ＰＯ３－４和ＮＯ－３的浓度影响不明显，海域总体为一贫营养盐区域。采用主成分分析表明控制水化学要素的主要因子是河流的输入和由此导致了的生物旺发。     

A pilot scale anoxic/oxic membrane bioreactor (A/O MBR) for woolen mill dyeing wastewater treatment

A pilot-scale( 10 m^3/d) anoxic/oxic membrane bioreactor( A/O MBR) was tested for dyeing wastewater treatment of woolen mill without wasting sludge in 125 days operation. Results showed that the effluent quality was excellent, i.e. effluent COD less than 25 mg/L,BOD5 under 5 mg/L, turbidity lower than 0.65 NTU, and colour less than 30 DT, and met with the reuse water standard of China. The removal rates of COD, BOD5, colour, and turbidity were 92.4%, 98.4%, 74% and 98.9%, respectively. Constant-flux operation mode was carried out in this study, and backwash was effective for reducing membrane fouling and maintaining constant flux. Membrane fouling had heavy impact on energy consumption. More attention should be paid on pipe selection and design for the sidestream MBR system, too.     

城市生活垃圾渗透系数测试研究

采用常水头测渗实验，对不同压实密度和水力梯度下的新鲜垃圾与陈垃圾的渗透系数进行测试，根据达西定律求得渗透系数值。由于垃圾的不均匀性、小颗粒的运动和大孔隙沟道流的形成和改变，实验初始阶段渗透系数值先增大至峰值，然后缓慢降低直至趋于稳定。实验稳定后，新鲜垃圾压实密度为0．75—0．95t／m^3时，渗透系数值约为1．26E-03～1．43E-03cm／s。陈垃圾在压实密度分别为1．2和1．4t／m^3时，渗透系数为8．29E-04和1．35E-04cm／s。     

SBR活性污泥中的主要微生物类群及其基本生态规律初探

本文重点探讨采用ＳＢＲ活性污泥法处理有机磷农药（乐果）生产废水的工艺中，ＳＢＲ内的活性污泥的主要微生物类群、特征、功能以及与环境因子、废水处理运行状况的关系。     

Cyanide Removal by Chinese Vegetation. Quantification of the Michaelis-Menten Kinetics (6 pp)

Background Little is known about metabolism rates of environmental chemicals by vegetation. A good model compound to study the variation of rates among plant species is cyanide. Vascular plants possess an enzyme system that detoxifies cyanide by converting it to the amino acid asparagine. Knowledge of the kinetic parameters, the half-saturation constant (Km) and the maximum metabolic capacity (vmax), is very useful for enzyme characterization and biochemical purposes. The goal of this study is to find the enzyme kinetics (KM and vmax) during cyanide metabolism in the presence of Chinese vegetation, to provide quantitative data for engineered phytoremediation, and to investigate the variation of metabolic rates of plants. Methods Detached leaves (1.0 g fresh weight) from 12 species out of 9 families were kept in glass vessels with 100 mL of aqueous solution spiked with potassium cyanide at 23°C for 28 h. Four different treatment concentrations of cyanide were used, ranging from 0.44 to 7.69 mg CN/L. The disappearance of cyanide from the aqueous solution was analyzed spectrophotometrically. Realistic values of the half-saturation constant (KM) and the maximum metabolic capacity (vmax) were estimated by a computer program using non-linear regression treatments. As a comparison, Lineweaver-Burk plots were also used to estimate the kinetic parameters. Results and Discussion The values obtained for KM and vmax varied with plant species. Using non-linear regression treatments, values of vmax and KM were found in a range between 6.68 and 21.91 mg CN/kg/h and 0.90 to 3.15 mg CN/L, respectively. The highest vmax was by Chinese elder (Sambucus chinensis), followed by upright hedge-parsley (Torilis japonica). The lowest vmax was demonstrated by the hybrid willow (Salix matssudana x alba). However, the highest KM was found in the water lily (Nymphea teragona), followed by the poplar (Populus deltoides Marsh). The lowest KM was demonstrated by corn (Zea mays L.). The values of vmax were normally distributed with a mean of 13 mg CN/kg/h. Conclusions Significant removal of cyanide from aqueous solution was observed in the presence of plant materials without phytotoxicity, even at high doses of cyanide. This gives rise to the conclusion that the Chinese plant species used in this study are all able to efficiently metabolize cyanide, although with different maximum metabolic capacities. A second conclusion is that the variation of metabolism rates between species is small. All these plants had a similar KM, indicating the same enzyme is active in all plants. Recommendations and Outlook Detoxification of cyanide with trees seems to be a feasible option for cleaning soils and water contaminated with cyanide. For phytoremediation projects, screening appropriate plant species adapted to local conditions should be seriously considered. More chemicals should be investigated to find common principles of the metabolism of environmental chemicals by plants.