北京城市发展新区土地利用景观格局分析

以北京南部城市发展新区典型代表———房山、大兴、通州3处作为研究区,运用马尔科夫转移矩阵和景观格局指数的方法,进行土地利用变化和景观格局分析。通过对2001—2006年、2006—2011年两个时段的对比分析,发现2001—2006年研究区存在草地、林地、耕地等非建设用地类型面积下降,建设用地面积上升的趋势,且2006—2011年该趋势更加明显。结果表明研究区自然景观向人文景观变革迅速,并面临着后备土地资源不足等问题,亟需调整土地利用方式并优化景观系统空间格局。     

Comprehensive health condition assessment on partial sewers in a southern Chinese city based on fuzzy mathematic methods

A self-developed sewer health assessment system using the fuzzy comprehensive evaluation and analytical hierarchy process was applied to give a comprehensive health condition evaluation on part of the local sewers in a southern Chinese city based on the sewer video data collected by a sewer inspection closed circuit television （CCTV） robot. Aside from the overall condition evaluation, the structure, function, and stability status of the sewer were also analyzed using the method. A comprehensive index H was proposed to give the overall health condition of pipes with different defects, and Ht, Hs, and If were used to quantify the defects affecting the tightness, stability, and function of the pipe, respectively. Results show that 48% of the inspected pipes were in good condition （0〈H〈0.25）, and about 33% of the sewer pipes analyzed were categorized to be at severe or urgent condition levels （H 〉 0.5）, although most of the pipes were installed only within five years. Frequent sedimentation affects the function of the sewer, and deformation and joint damage affect the structure of the sewer.     

An extension of Multiple Greek Letter method for common cause failures modelling

Common cause failure describes a condition where several components share the same source of failure that causes them to fail or become unavailable simultaneously. The objective of this paper is to present an improved approach to common cause failure modelling within reliability analyses. The currently used methods allow one component to share common characteristics with only one group of components, which may be affected by the same source of failure. Therefore, an improved method was developed, where components can be assigned to several groups of components that are susceptible to faulty operation with respect to their similar characteristics. A mathematical derivation of the method is presented and the theory is applied to smaller theoretical samples and to a simplified real example. The results show that the new method enables a more detailed reliability analysis. The results prove that consideration of common cause failures using the improved method may decrease the system reliability compared to traditional common cause failure consideration. The system reliability decreases more, if the redundant components have more similarities and are therefore assigned to several common cause failure groups.     

大气环境质量灰色聚类关联分析法的应用研究

在讨论大气环境质量灰色聚类关联评价法的基础上,通过应用实例和与灰色聚类法及灰色关联法的比较分析,验证了这种评价法的合理性和可靠性。     

一种改进的灰关联分析法在水质评价中的应用

灰关联分析法已被广泛应用于水质评价结论的定量化,但其存在不同层次上的缺陷;为此本文对其进行了改进.先将各断面的多个污染指标分成几个低层次子集,将其元素归一化后得出相应的关联系数,通过赋予一定权重求出低层次子集的关联度,最后求出较高层次的关联度,并列出关联系数矩阵.这样可以容易地看出各断面水质属于哪个级别.此外,通过一应用实例并与现已流行的众多灰关联改进方法进行了比较,论证了这种改进方法的优越性.     

环氧乙烷生产装置的安全分析与评价

综合运用道化学公司火灾、爆炸危险指数评价法,事故树分析以及事件树分析对环氧乙烷生产装置进行安全评价,定量地得出装置的危险程度,定性地分析了各危险因素的大小以及系统中各元件的故障率对事故发生概率的影响程度,并提出了改进措施.结果表明,该装置的危险程度很大,必须加强安全生产管理,采取有效措施控制氧气的浓度,从而降低危险性等级,保证生产安全.     

武汉市某区域大气颗粒物的测定与分析

采用电感耦合等离子体原子发射光谱法对TSP环境样品和尘源样品中的S、Si、Ti、Al、As、Ca、Pb、V等30余个元素组份进行分析并计算出各元素的含量,得到本区域大气环境TSP和污染尘源元素特征谱,并通过比较微波消解与加热消解两种方法的优劣,确定出较适应消解方法.结果表明,该区域中的A区污染源主要来自道路交通尘源和土壤尘源,B区污染源来自土壤尘源和建筑尘源.     

氯气泄漏后毒害区的估算及泄漏的处置

运用毒害区计算方法对本部贮存的氯气泄漏后扩散的半径进行估算,同时以扩散的半径作参考,提出氯气泄漏的处置方法.     

Ecological selection of bacterial taxa with larger genome sizes in response to polycyclic aromatic hydrocarbons stress

Polycyclic aromatic hydrocarbons(PAHs) are ubiquitous priority pollutants that cause great damage to the natural environment and health. Average genome size in a community is critical for shedding light on microbiome’s functional response to pollution stress within an environment. Here, microcosms under different concentrations were performed to evaluate the selection of PAHs stress on the average genome size in a community. We found the distinct communities of significantly larger genome size w...     

估算天津环境中γ-HCH归宿的逸度模型

以全天津市为研究区域,利用稳态假设的逸度模型,用Matlab软件计算了γ-HCH(林丹)在环境各相中的浓度和相间迁移通量.γ-HCH在天津气、水、土壤、沉积物、鱼、作物、蔬菜各相中的浓度分别为1.57×10^-11、7.95×10^-7、1.17 × 10^-4、4.58×10^-4、6.03×10^-4、1.60×10^-4和6.42×10^-5mol/m³,在数量级上与实测值吻合很好.估算结果表明农业施用和农药厂废水是该地区环境中γ-HCH最主要的来源,最大的汇是土壤和沉积相(占环境中总量的99%),最主要的迁移过程是水-沉、气-土的扩散和沉降,土壤和沉积物中的降解是γ-HCH消失的最主要途径.