高锰酸盐指数测定中校正系数K值的变化验证

运用数理统计方法,验证了高锰酸盐指数测定的校正系数K值在4～5h内不会随时间和水样的变化而变化,K值不必每个样品都测定。     

人工神经网络模型和公路复垦土地适宜性评价

提出了人工神经网络用于公路临时用地复垦土地适宜性评价，利用该模型对京大高速公路山西段复垦山西段复垦土地进行了适宜性评价，探讨了人工神经网络在土地复垦适宜性评价时的特点和注意问题。     

不锈钢薄板拉伸、冲压成形性能的试验研究

采用德国产SCHENCKTREBELRM2 5 0电子万能试验机对SUS3 0 4不锈钢 0 .5mm薄板进行了拉伸试验 ,研究了SUS3 0 4不锈钢薄板的硬化指数 (n值 )、屈服强度 (σs)、极限强度 (σb)、均匀延伸率(δ)等机械性能 ,并分析了SUS3 0 4薄板的冲压成形性能     

Carbon isotope ratios in logged and unlogged boreal forests: Examination of the potential for determining wildlife habitat use

Due to assimilation of recycled CO₂ from litter decomposition and photosynthetic changes in carbon fractionation at low light levels, the foliage at the base of a forest is often more depleted in¹³C compared to that exposed to the atmosphere in either the canopy or in open clearings. This is referred to as the canopy effect. African research has indicated that these habitat differences in foliar ¹³C can be substantial enough to affect the carbon isotope ratios of resident fauna. Previous work documenting a 30-year chronology on moose teeth from Isle Royale National Park indicated a progressive depletion in¹³C and suggested that this could be due to forest regrowth following extensive burning. The present study examined the assumption implicit in this hypothesis that foliar ¹³C varies between open and closed boreal forest sites. I found a marginal canopy effect of 2 ¹³C difference between upper canopy and ground flora for a forest in northwestern Ontario and an average difference of 1.2 in under- and mid-story vegetation between closed forests and open clear-cuts. Because of these small differences, the utility of carbon isotope analysis in quantifying temporally integrated exploitation of deforested habitats will be low for northern boreal locations. In denser forests, such as those in the tropics or western North American where the canopy effect can be expected to be much greater, ¹³C analysis may still offer some promise for determining selection by wildlife of disturbed habitats.     

西藏自治区土地资源的适宜性评价与利用

本文综合评价了西藏自治区土地资源的适宜性及其质量．阐明了影响土地资源潜力发挥的主要限制因素，分析了土地资源利用现状、存在问题和开发潜力。并在此基础上、提出了西藏自治区土地资源合理开发利用的方向、对策和措施。     

模糊集值统计法在煤矿安全评价指标权值中的应用

应用模糊集值统计的理论 ,对煤矿安全评价中具有随机性和模糊性的指标进行数学分析 ,进一步改进了其权值的确定方法 ,使其更加符合实际情况 ,并对由此得出的权值进行了可靠性分析。通过实例表明 ,该方法克服了经典统计法的不足 ,提高了煤矿安全评价的实用性和科学性     

河南省煤化工行业环境风险等级划分研究

基于目前国家建立环境污染责任保险制度的规划需求和河南省当前新发展形势需要,选择以河南省典型高污染、高风险行业(即煤化工行业)为研究对象.在对相关理论进行分析的基础上,识别影响河南省煤化工行业的环境风险因子,并确定指标的评估标准(权重及评分结果).遵照指标体系的建立原则,采用层次分析法,从内在性和外在性两方面因素构建煤化工行业环境风险等级划分指标体系,进一步将评分结果与环境风险等级比对,最终将煤化工行业的环境风险等级划分为5个等级,为河南省环境污染责任保险制度的建立奠定基础.     

The effects of landscape-level disturbance on the composition of Minnesota caddisfly (Insecta: Trichoptera) trophic functional groups: evidence for ecosystem homogenization

Over 300,000 caddisfly specimens representing 249 species were collected from nearly 250 sites throughout Minnesota during 2000 and 2001 to determine the effects of human disturbance on the composition of caddisfly trophic functional groups at the landscape level. Canonical correspondence analysis determined that stream width was the most important variable influencing functional group composition in regions of the state with relatively low disturbance, and that differences in the caddisfly fauna between sizes of streams generally followed trends predicted by the river continuum concept. In regions of the state with moderate disturbance, both stream width and the percentage of disturbed habitat upstream of a site were important variables influencing functional group composition. In highly disturbed regions, no variables corresponded to changes in the composition of caddisfly functional groups. Instead, ecosystems were homogeneous: fine-particle filtering collectors dominated in all sizes of streams. The observed aquatic ecosystem homogenization is attributed mostly to input of fine-particle organic and inorganic sediment from extensive agriculture.     

风险评价标准值初探

提出了风险指标和ALARP原则的含义,从风险评价的ALARP原则出发,得出个人风险评价标准值和社会风险评价标准值的制定方法。     

长江入海口北支沿海滩涂养殖区底泥重金属污染特征及趋势评价

对长江入海口北支沿海滩涂养殖区底泥重金属污染的总体水平进行调查,结果表明,滩涂养殖区底泥重金属含量满足海洋沉积物质量一类标准要求,污染程度属于安全Ⅰ级水平,重金属潜在生态危害属轻微级别,6种重金属潜在生态危害由大到小排序依次为Cd﹥Hg﹥Cu﹥Cr﹥Pb﹥As,2005年～2011年,底泥重金属污染程度均处于安全的Ⅰ级水平。