邢台市畜禽粪尿污染现状分析及对策

利用统计资料和文献数据,结合国内外研究,确定邢台市畜禽粪尿资源的计算参数和计算方法,估算了邢台市畜禽粪尿产生量及其中的氮磷养分的含量、CODCr含量和单位耕地负荷量,并分地区提出畜禽养殖污染负荷警报值,为邢台市畜禽养殖污染防治提供科学依据与技术支持。     

The Euler Number as an Index of Spatial Integrity of Landscapes: Evaluation and Proposed Improvement

The spatial integrity of a habitat or landscape is determined by the occurrence of habitat fragments and of perforations inside them. A landscape is said to have less spatial integrity with increasing numbers of fragments and perforations. The Euler number (ε) is a numerical measure of spatial integrity, based upon the difference |n _f −n _p | between the number of fragments (n _f ) and the number of perforations (n _p ). In this contribution, ε is evaluated, and an improvement is presented as a new index ε*, which is a combination of two metrics (ε _i , ε _d ) based on n _f and n _p . The term ε _i quantifies the intensity of perforation and/or fragmentation. The term ε _d measures the extent to which fragmentation predominates perforation, and vice versa. The intensity and dominance measures are combined into an Euclidean distance measure, generating the new ensemble value ε*, calculated as ε*= (n _f +n _p )⁻¹√[1 +n _f ²]. Use, sensitivity, and application of ε*, ε _i , and ε _d are illustrated using percolation maps. Application of the new metrics by environmental scientists is encouraged because (1) no negative values can be generated with ε*, ε _i , and ε _d ; (2) the range of ε*, ε _i , and ε _d is fixed; (3) process dominance and intensity are both assessed; (4) ε*, ε _i , and ε _d are easy to calculate and to interpret; and (5) ε* is not only based upon |n _f −n _p |, as ε is. Guidelines for practical use by means of a biplot of ε _i and ε _d are given.     

家用洗衣机微生物污染状况研究

在生活中,洗衣水往往是被人们所忽略的污染源。为了人们更加健康的生活更加健康的洗衣,本文对家用洗衣机内外筒以及洗衣水中细菌总数和大肠菌群数进行了取样测定,结果表明,各种样品的细菌总数结果很相近,并且远远超出了公共用品中其它公共用品卫生的标准,即细菌总数评价指标不大于300 cfu/25cm2;洗衣机内外筒的细菌总数结果相近。最后,本文通过分析其造成的污染状况,从而引导人们养成科学的洗衣习惯。     

我国部分城市和地区居民龋均与饮用水氟含量的关系研究

为探讨饮水氟化在我国的可行性及饮水氟含量的安全值,在全国牙痛防治指导组1995年全国城乡居民口腔健康流行病学调查资料的基础上,对我国部分城市和地区饮用水氟含量进行了检测,对饮用水氟含量与居民龋均数据进行相关性分析。结果显示,在安全的饮水氟浓度范围内,龋均与饮用水氟浓度之间存在负相关关系,表明适度饮水氟化可以有效降低龋均;当水氟浓度超过安全临界点时,龋均与饮用水氟浓度呈正相关关系,说明高氟含量饮用水不仅可以导致氟中毒流行,也会提高龋病的发病率。我国饮用水氟含量的适宜范围为0.8~1.0 mg／L。研究发现饮用水氟浓度与龋均之间没有形成很好的线性关系,说明饮用水氟含量并不是龋病的唯一控制因素(说明龋病受多因素控制)。     

区间数多属性决策在飞机一发失效应急程序方案优选中的应用

针对在飞机一发失效应急程序方案的选择中,很多定量因素难以精确量化的问题,将区间数多属性决策运用到飞机一发失效应急程序方案的优选中,构建了评价指标体系。此评价指标体系应用基于理想解的区间数多属性决策的相对隶属度法来选择最佳方案,该方法通过计算并查找现有方案的相对隶属度最大值来确定最佳方案。最后举例说明如何在实际中使用此方法。     

BLEVE: Safety distances estimation by simple models based on the Jakob number

One of the most important points in the design of inherently safe processes is to estimate reliable distances among process units at preliminary stages of the plant project to minimize losses and damages caused by the potential occurrence of technological accidents. Therefore, in this paper the achievement of simple, general, dimensionless and reliable equations (Simple Dimensionless Models SDMs) for the direct estimation of safety distances considering the occurrence of BLEVE (Boiling Liquid Expanding Vapour Explosion) event, is proposed. The developed models directly relate safety distances with critical design/operation variables (involved substance, vessel volume, target vulnerability and explosion temperature), which are easily accessible at early stages of the plant project. SDMs are achieved by analysing the influence of these simple variables on the safety distances, which are estimated using a selected rigorous model (Reference Model R_fM). This task is simplified by the incorporation of the Jakob Number as an input variable, allowing to obtain dimensionless models and simultaneously an adequate representation of the explosion conditions and the involved substances. As result, the achieved SDMs demonstrate a particularly good fit with respect to the R_fM estimations and, at the same time, reliability and versatility. As it is shown in the analysed study cases (involving critical decision variables for the process design and the system safety), the SDMs prove to be also accurate, general, and easily incorporable into more complex optimization problems (QRA analysis, design of emergency plans, safety distance estimation to minimize the probability of domino effects, optimal layout designs, among others).     

夏季高湿度条件下北京市气溶胶颗粒物粒谱特征研究

2007年8月,利用粒谱分析仪(APS)、振荡天平颗粒物分析仪(TEOM)和碳黑分析仪(BC)观测北京市大气气溶胶可吸入颗粒物(PM10),研究高湿度气象条件对气溶胶颗粒物吸湿长大的影响.结果表明,PM10质量浓度与碳黑质量浓度在静稳天气状况下相关系数达0.82,而对于颗粒物数浓度与PM10质量浓度,静稳与非静稳天气状况下两者的相关性并不一致,颗粒物数浓度及1μm的细粒子在粒谱分布中所占的比重显著增加.气溶胶颗粒物粒谱变化结果说明,在高湿度条件下颗粒物粒径明显吸湿增长.     

清水江水质评价与变化趋势的显著性分析研究

以贵州省黔南州清水江监测数据为例,采用五元联系数方法进行水质评价.分析表明,该方法是一种客观有效的评价方法,评价茶园、兴仁桥两个断面均优于环境规划类等级.针对TP、氟化物指标浓度严重超标问题,采用Daniel趋势检验法测试2006年-2010年指标浓度变化的显著性,结果说明：5年内清水江重安江大桥河段TP、氟化物浓度降低的趋势显著性较高;而兴仁桥河段TP浓度降低的趋势显著性偏低;氟化物浓度几乎不变,变化不显著.由此说明,黔南州清水江水质得到改善.     

地累积指数法评价多金属环境质量的方法优化探索:以农业发达地区为例

准确合理的土壤污染评价方法是进行区域性土壤污染评价的前提.将三角模糊数引入地质累积指数法,结合α-截集技术以及Latin Hypercube抽样(LHS)随机模拟方法对研究区重金属含量差异较大的5种不同土壤类型(潮土、风沙土、黄绵土、褐土和新积土)分别进行土壤重金属(Cd、Hg、As、Pb和Cr)累积性评价,能够避免因...     

基于FAHP的航空维修安全风险管理研究

航空维修对于保障飞行安全至关重要,如何进行航空维修安全风险管理是需要研究的问题.为此应用模糊层次分析法(FAHP),基于"人-机-环-管-接口"的理论,研究了影响航空维修安全的各种影响因素.利用三角模糊数并通过专家判断来构建三角模糊互补判断矩阵.按照层次结构模型和模糊层次分析法的步骤,对各影响因素进行了层次单排序和总排序,并把结果进行了分级和排序.结果表明,影响维修安全的主要因素为企业的规章制度、安全文化和维修人员的惯性违章等航空维修应该重点改善这3个因素并兼顾其他影响因素.研究表明,模糊层次分析法有助于确定安全风险管理的重点.