重金属Zn、Pb和Cd对可口革囊星虫的急性毒性作用

研究了必需元素Zn及非必需元素Pb、Cd对可口革囊星虫(Phascolosoma esculenda)的急性毒性作用,得到Zn2 的48 h LC50和96 h LC50分别为61.09、10.91 mg/L;pb2 的48 h LC50和96 h LC50分别为29.44、10.59 mg/L;Cd2 的48 h LC50和96hLC50分别为10.69、4.46mg/L.估算得到Zn、Pb和Cd对可口革囊星虫的安全浓度分别为0.55、0.53和0.22mg/L.     

东海赤潮频发区石油烃的季节分布特征

根据2002年4月～2003年3月对东海赤潮高发区表层海水中石油烃污染状况进行的四季现场调查,探讨了该海区石油烃的季节分布特征.结果表明,该海域受到了石油烃的轻度污染,表层海水中石油烃的含量具有明显的时间差异.石油烃的平均浓度夏季最高(0.124 mg/L),春、秋季居中(约0.08 mg/L),冬季最低(0.032 mg/L).并根据调查区域油类污染物排海量及水文情况,对各季节石油烃的水平分布特征进行了初步的分析.     

河南省雷暴日数时空分布的非均一性特征

利用河南省气候中心编制的97个台站1961-2000年雷暴日数的资料,对该省境内雷暴发生的时空分布非均一性进行了分析.结果表明:全省平均雷暴日数有明显下降的趋势;雷暴日数站间偏度系数具有明显的年际变化特征,80%的年代表现为正偏;而其峰度系数则60%的年份为负值,且具有明显的年际变化特征.年平均雷暴日数及其均方差空间分布型态比较一致.豫北、豫西和豫东南分别出现3个雷暴高发区,其中豫东南强度最大,豫西强度与其相当,豫北相对较小.历年雷暴日数以正偏为主;峰度系数则以负值为主.河南省除信阳地区外,各站雷暴日数在0.05置信水平上服从正态分布.     

基于格子Boltzmann的非均质采空区瓦斯运移仿真方法

瓦斯在采空区内运移造成工作面上隅角瓦斯超限是煤矿安全的重大隐患.为揭示采宅区瓦斯运移规律,提出基于格子Boltzmann的非均质采空区瓦斯运移仿真方法.综放采场采空区是由非均质多孔介质组成的空间,大气和瓦斯混合气体在采空区的流动是非常复杂的具有层流、过度流和紊流的渗流运动.基于修正的Brinkman-Forchheimer-Darey定律,建立非均质采空区瓦斯运移的控制方程组.由于该方程组求解复杂,分别建立瓦斯渗流速度场和瓦斯浓度场的格子Boltzmann模型.通过格子Boltzmann模型的演化,实现采空区瓦斯运移的仿真.模拟实例表明,用该方法进行仿真可以得到任何时刻采空区内任意位置瓦斯和大气混合气体的流动速度和压力以及瓦斯浓度等数据,同时也可以得到采空区流线分布规律、速度变化规律、采空区压力的变化规律和采空区瓦斯运移规律.该方法能将时间、空间和系统行为结合起来,可在直观的条件下完成对地下煤矿采空区瓦斯运移态势的精确分析与模拟,可为揭示综放采场采空区上隅角瓦斯超限的原因提供一种新的方法.     

区域水环境安全动态评价方法及其应用

为了对水环境安全状况进行有效评价,建立了以改进AHP法赋权的综合指数法为核心内容的区域水环境安全评价体系,并结合动态趋势分析法对河北省区域内1999-2006年的水环境安全状况进行了动态发展趋势评价.结果表明,在评价时间段内,河北省水环境安全状况总体上呈波动上升趋势,其中水量安全度波动较大,这说明水量安全问题是河北省水环境安全的最薄弱环节,是制约河北省水环境修复的核心要素.该方法的应用可为区域水环境的修复提供有针对性的指导.     

四苯基双酚A二磷酸酯及复配体系阻燃环氧树脂的热动力学分析

采用热分析仪对四苯基双酚A二磷酸酯(BDP)及复配APP体系阻燃环氧树脂(EP)进行TG分析,研究BDP及其复配体系阻燃EP降解的过程,并在动力学理论模型基础上计算阻燃EP的活化能.结果表明,与未阻燃EP相比,阻燃EP在600 ℃时残炭率增加,15% BDP阻燃EP的残炭率由未阻燃的20.41%增加到28.06%,15% BDP+9% APP阻燃EP的残炭率增加到34.78%;BDP及其复配体系阻燃EP的活化能显著提高,15% BDP阻燃EP的活化能由未阻燃的80.39 kJ/mol提高到141.06 kJ/mol,15% BDP+9% APP阻燃EP的活化能提高到199.68 kJ/mol.研究表明,阻燃EP体系耐热性能好,阻燃效果明显,且复配体系阻燃效果进一步提高.     

失效路径长度对结构系统安全可靠性的影响

运用钢结构系统可靠性的安全评定原则,以立体车库钢结构系统为研究对象,建立主要失效模式安全余量方程,计算失效概率.在对风载荷和地震载荷分布进行模拟的基础上,通过对立体车库大型钢结构系统的算例进行分析,探讨了失效路径长度对大型钢结构系统失效准则与安全可靠性的影响,提出在结构整体承载能力未出现下降的情况下,失效路径长度取得越大越好的结论.该结论对大型钢结构可靠性的工程应用有指导意义.     

火电厂应急管理信息系统研究

分析火电厂事故应急管理的特点,即事故应急响应的快速性、高效性及可预测性;从技术框架设计、网络设计、数据库设计、系统安全性设计4方面分析火电厂应急管理信息系统的总体设计方案;分析火电厂应急管理系统的业务模块划分及主要功能;讨论火电厂应急管理信息系统的实现方式及主要工作界面.结果表明,在系统三维仿真环境中可以进行重大危险源辨识、风险评估以及有效组织模拟演练,从而提高火电厂的应急管理水平.研究表明,高质量的仿真环境与科学的逻辑分析可为临灾状态下的应急救援决策提供快速、有效的技术支持,具有重要现实意义.     

Aerobic degradation of methyl tert-butyl ether by a Proteobacteria strain in a closed culture system

The contamination of methyl ten-butyl ether （MTBE） in underground waters has become a widely concerned problem all over the world. In this study, a novel dosed culture system with oxygen supplied by H2O2 was introduced for MTBE aerobic biodegradation. After 7 d, almost all MTBE was degraded by a pure culture, a member of β-Proteobacteria named as PMI, in a closed system with oxygen supply, while only 40% MTBE was degraded in one without oxygen supply. Dissolved oxygen （DO） levels of the broth in closed systems respectively with and without H2O2 were about 5-6 and 4 mg/L. Higher DO may improve the activity of monooxygemase, which is the key enzyme of metabolic pathway from MTBE to tert-butyl alcohol and finally to CO2, and may result in the increase of the degrading activity of PM1 cell. The purge and trap GC-MS result of the broth in closed systems showed that tea-butyl alcohol, isopronol and acetone were the main intermediate products.     

Distribution characteristics of dissolved organic carbon in annular wetland soil-water solutions through soil profiles in the Sanjiang Plain, Northeast China

Overwhelming evidence reveals that concentrations of dissolved organic carbon （DOC） have increased in streams which brings negative environmental impacts. DOC in stream flow is mainly originated from soil-water solutions of watershed. Wetlands prove to be the most sensitive areas as an important DOC reserve between terrestrial and fluvial biogeosystems. This reported study was focused on the distribution characteristics and the controlling factors of DOC in soil-water solutions of annular wetland, i.e., a dishing wetland and a forest wetland together, in the Sanjiang Plain, Northeast China. The results indicate that DOC concentrations in soilwater solutions decreased and then increased with increasing soil depth in the annular wetland. In the upper soil layers of 0-10 cm and 10-20 cm, DOC concentrations in soil-water solutions linearly increased from edge to center of the annular wetland （R^2 = 0.3122 and R^2 = 0.443）. The distribution variations were intimately linked to DOC production and utilization and DOC transport processes in annular wetland soil-water solutions. The concentrations of total organic carbon （TOC）, total carbon （TC） and Fe（II）, DOC mobility and continuous vertical and lateral flow affectext the distribution variations of DOC in soil-water solutions. The correlation coefficients between DOC concentrations and TOC, TC and Fe（II） were 0.974, 0.813 and 0.753 respectively. These distribution characteristics suggested a systematic response of the distribution variations of DOC in annular wetland soil-water solutions to the geometry of closed depressions on a scale of small catchments. However, the DOC in soil pore water of the annular wetland may be the potential source of DOC to stream flow on watershed scale. These observations also implied the fragmentation of wetland landscape could bring the spatial-temporal variations of DOC distribution and exports, which would bring negative environmental impacts in watersheds of the Sanjiang Plain.