论自然保护区旅游活动的生态影响

自然保护区逐渐打破传统的消极保护模式，寻求保护与发展的协调，开展起旅游活动，但由此带来的生态影响不容忽视。本文从建立自然保护区的主要目的出发，就旅游活动对生物多样性及生态景观的影响进行分析，认为在自然保护区开展旅游活动，要对旅游活动强度与游客量进行合理控制，按照生态旅游的方法进行合理规划与管理，使保护区获得可持续发展。     

363kV真空断路器支柱绝缘子模态及地震响应谱分析

当地震波的振动频率接近电力设备支柱绝缘子的固有振动频率时,可引发共振现象而导致设备损坏。针对363 kV真空断路器支柱绝缘子建立了有限元模型,对支柱绝缘子进行地震响应谱分析,可为支柱绝缘子结构的设计提供参考。首先对支柱绝缘子进行结构静力学分析,计算支柱绝缘子自身应力分布;其次进行有预应力模态仿真分析,计算出支柱绝缘子1-10阶振型对应的模态频率;最后在计算出各阶模态频率的基础之上,对断路器支柱绝缘子进行了地震响应谱分析,在x +y方向施加EI Centro波加速度频谱,计算出支柱绝缘子的最大应力分布和沿各坐标轴方向的最大形变位移。     

不同粒径尾矿中重金属水平迁移转化规律

针对桂北铅锌尾矿中重金属在水平方向上的释放、迁移和转化问题,利用尾矿为研究对象,通过降雨模拟装置进行径流冲刷试验,分析冲刷过程中尾矿重金属浓度和形态的变化。结果表明,在径流冲刷过程中,尾矿中重金属浓度整体呈下降趋势,深度对尾矿中重金属浓度变化的影响不明显,同一深度的尾矿,粒径与其重金属释放量呈负相关关系,粒径小于75μm时重金属Zn减少率高达24%。径流作用下,尾矿的粒径大小与迁移能力成反比。径流冲刷前后,尾矿中重金属含量下降,Cd,Zn和Pb的含量在弱酸提取态下分别减少2.4%,1.6%和0.3%。随降雨时间延长,液相可溶态重金属浓度未发生显著变化,固相颗粒态重金属浓度持续降低,液相颗粒态重金属含量减少最明显。     

有机过氧化物性质和安全性评价

介绍了有机过氧化物的性质、用途、安全性评价方法以及测试方法,要客观地评价有机过氧化物的安全性,必须通过多种方法来进行综合分析评定,为有机过氧化物的安全生产、使用、贮存和运输等提供科学的依据。     

漆酶对染料的脱色研究

利用来源于白毒鹅膏菌的粗漆酶与12种工业染料反应,结果发现其中7种染料颜色能被脱除.研究了直接影响黑G和中性黄GL的漆酶脱色的相关因素.试验发现,这两种染料在1h内与漆酶反应迅速,且特征颜色吸收峰(600nm/440nm )基本消失,其最适温度均为50℃、最适反应pH值范围分别为5-6和3-4,酶活力的增加可显著提高反应速率,但对总脱色率影响不大.在pH值为5、温度40℃条件下,5U/ml的漆酶与直接黑G和中性黄GL反应的Km值分别为3.2mg/L和25.1mg/L,Vmax值分别为2.70mg/L·min和3.25mg/L·min.     

MATLAB在储罐区蒸气云爆炸分析中的运用

针对储罐区蒸气云爆炸事故,通过建立蒸气云爆炸模型和运用MATLAB程序分析事故后果,得出了死亡、重伤、轻伤的区域半径,进而对伤害区域进行了划分,并将结果以图形的形式呈现,有利于安全人员直观地判断和分析事故后果.同时,借助MATLAB程序使整个分析过程更加简洁高效,有利于制定相应的预防和应急措施.     

Forecasting human exposure to atmospheric pollutants in Portugal – A modelling approach

Air pollution has become one main environmental concern because of its known impact on human health. Aiming to inform the population about the air they are breathing, several air quality modelling systems have been developed and tested allowing the assessment and forecast of air pollution ambient levels in many countries. However, every day, an individual is exposed to different concentrations of atmospheric pollutants as he/she moves from and to different outdoor and indoor places (the so-called microenvironments). Therefore, a more efficient way to prevent the population from the health risks caused by air pollution should be based on exposure rather than air concentrations estimations. The objective of the present study is to develop a methodology to forecast the human exposure of the Portuguese population based on the air quality forecasting system available and validated for Portugal since 2005. Besides that, a long-term evaluation of human exposure estimates aims to be obtained using one-year of this forecasting system application. Additionally, a hypothetical 50% emission reduction scenario has been designed and studied as a contribution to study emission reduction strategies impact on human exposure.To estimate the population exposure the forecasting results of the air quality modelling system MM5-CHIMERE have been combined with the population spatial distribution over Portugal and their time-activity patterns, i.e. the fraction of the day time spent in specific indoor and outdoor places. The population characterization concerning age, work, type of occupation and related time spent was obtained from national census and available enquiries performed by the National Institute of Statistics. A daily exposure estimation module has been developed gathering all these data and considering empirical indoor/outdoor relations from literature to calculate the indoor concentrations in each one of the microenvironments considered, namely home, office/school, and other indoors (leisure activities like shopping areas, gym, theatre/cinema and restaurants). The results show how this developed modelling system can be useful to anticipate air pollution episodes and to estimate their effects on human health on a long-term basis. The two metropolitan areas of Porto and Lisbon are identified as the most critical ones in terms of air pollution effects on human health over Portugal in a long-term as well as in a short-term perspective. The coexistence of high concentration values and high population density is the key factor for these stressed areas. Regarding the 50% emission reduction scenario, the model results are significantly different for both pollutants: there is a small overall reduction in the individual exposure values of PM₁₀ (<10 μg m^?3 h), but for O₃, in contrast, there is an extended area where exposure values increase with emission reduction. This detailed knowledge is a prerequisite for the development of effective policies to reduce the foreseen adverse impact of air pollution on human health and to act on time.     

基于CFD的井喷失控喷射火温度场和辐射场模拟仿真

采用CFD方法研究了井喷失控喷射火,阐述了模拟仿真所需的定解条件,论述了模拟仿真采用的数值计算方法,通过模拟仿真得出了井喷失控喷射火温度场和热辐射场的分布规律.结论表明采用CFD方法研究井喷失控喷射火是切实可行的.     

Relations between PM10 composition and cell toxicity: a multivariate and graphical approach

Previous studies have used particle mass and size as metrics to link airborne particles with deleterious health effects. Recent evidence suggests that particle composition can play an important role in PM-toxicity; however, little is known about the specific participation of components (individually or acting in groups) present in such a complex mixture that accounts for toxicity. This work explores relationships among PM(10) components in order to identify their covariant structure and how they vary in three sites in Mexico City. Relationships between PM(10) with cell toxicity and geographical location were also explored. PM(10) was analyzed for elemental composition, organic and elemental carbon, endotoxins and the induction of inhibition of cell proliferation, IL-6, TNFalpha and p53. PM(10) variables were evaluated with principal component analysis and one-way ANOVA. The inhibition of cell proliferation, IL-6 and TNFalpha were evaluated with factorial ANOVA and p53 with the Welch test. The results indicate that there is heterogeneity in particle mass, composition and toxicity in samples collected at different sites. Multivariate analysis identified three major groups: (1) S/K/Ca/Ti/Mn/Fe/Zn/Pb; (2) Cl/Cr/Ni/Cu; and (3) endotoxins, organic and elemental carbon. Groups 1 and 3 showed significant differences among sites. Factorial ANOVA modeling indicated that cell proliferation was affected by PM concentration; TNFalpha and IL-6 by the interaction of concentration and site, and p53 was different by site. Radial plots suggest the existence of complex interactions between components, resulting in characteristic patterns of toxicity by site. We conclude that interactions of PM(10) components determine specific cellular outcomes.     

矿山选矿药剂对生态环境的污染与防治探讨

矿山选矿药剂对生态环境的污染、二次污染和复合污染等问题的研究，国内外研究相对比较缺乏。从选矿药剂对生态环境的污染作用、选矿药剂污染与危害和选矿药剂的污染治理方面进行了综述和比较分析。为了减少选矿药剂对生态环境的污染，探讨了选矿药剂的环境污染治理和控制方法。