基于AHP-Fuzzy的高处坠落危险性评价研究

高处坠落事故在建筑安全生产事故中所占的比率最大。预防和控制高处坠落事故始终是建筑业应解决的重要问题,高处坠落危险性评价是预防与控制高处坠落事故的重要手段。以高处坠落风险为研究对象,通过对高处作业＂人—机—环境—管理＂复杂系统进行分析,建立生产人员素质因素、生产设备因素、环境条件因素、安全管理因素等4个大类和23个小类的危险性评价指标体系。在层次分析法和模糊综合评价法等研究基础上,构建了高处坠落风险的AHP-Fuzzy评价模型,确定了各层次的权重集。对给出的实例进行评价,评价结果符合实际情况。结果表明,基于AHP-Fuzzy的高处坠落危险性评价方法是可靠与实用的,并对高处坠落危险性的评判有指导意义。     

干挂石材幕墙火蔓延数值模拟研究

采用数值模拟技术研究了干挂石材幕墙发生燃烧情况下的火蔓延及羽流特点。通过外部高温辐射源点燃了具有4 cm厚PMMA保温层但保温材料和外层钢板间存在2 cm缝隙下的干挂石材幕墙,对模拟结果的温度场、速度场和热释放速率的分析表明其火蔓延速度较泡沫壁面低,但碳化区形状规则,蔓延路径清晰;虽然热释放速率低,但相对而言火焰高度较高,火焰宽度较小,而且其火羽流呈现点火源的特点。     

改造现有工艺回收地面计量天然气

为解决牙哈作业区A区块3口井在见水后含水上升较快、单井产液量增加、现有装置处理能力不足,导致A区块所有生产井不能全部进站的问题,同时为提高最终采收率,需要延长见水时间,见水后控制含水的上升趋势。这就要求掌握含水井的生产动态,而现有装置无法对单井的含水进行计量,塔里木油田公司牙哈作业区A区块建造集中试采装置,文章介绍了改造前后的工艺流程及改造效果。     

非洲地区环境法对中国石油海外业务影响分析

文章在调研中国石油非洲地区主要业务国环境法律法规的基础上,阐述了这些国家在环境管理方面的现状,提出了中国石油应对非洲地区环境法律制约的措施和建议,包括可行性研究阶段的法规调研要兼顾非洲习惯法,及早应对政策风险,项目实施过程严格落实环境影响评价、环境审计、环境许可和环境应急管理制度等。     

清洁发展机制与中国对策

清洁发展机制是应对气候变化国际法律制度之下的补充性履约措施。通过阐述清洁发展机制的渊源、清洁发展机制的实质内涵和基本特征,总结中国清洁发展机制项目实践,揭示中国应用清洁发展机制的偏差,预测清洁发展机制发展方向,指出中国将被迫退出清洁发展机制,提出中国面向清洁发展机制的具体对策。     

教师人文素养修炼的再思考

人文素养是以人文知识、人文态度和人文精神为构成要素的人的素质。教师修炼人文素养,可以促进专业发展,提升师德水平。修炼的途径和方法包括更新理念、广泛阅读、提升人格、健康心理等。     

Analysis of water quality factors influencing the speciation of inorganic nitrogen using GRA

Based on the water quality data from 2006 to 2008, grey relational analysis (GRA) is used to analyze factors that may have influence on the speciation of inorganic nitrogen in the Chengdu section of middle Min river. The results show that water temperature, changing from 20.2 +/- 2.7, 13.4 +/- 5.7 and 16.8 +/- 5.6 degrees C, is the first restrictive factor for the speciation of inorganic nitrogen; it is negatively correlated with the ratio of total ammonia nitrogen to total inorganic nitrogen contents [m(AN)/m(TIN)] in three different periods of wet season, dry season and year-round. The average pH values for years, in wet and dry periods are 7.6 +/- 0.4, 7.3 +/- 0.3 and 7.8 +/- 0.2, respectively, and have different influences in different seasons. It is the second restrictive factor and positive correlation between pH and m(AN)/m(TIN) in wet season and through the year yet it is the fourth factor in dry seasons. The values of dissolved oxygen (DO), which are 4.6 +/- 1.4, 4.6 +/- 2.4, 4.6 +/- 2.0 respectively, is the third factor and negatively correlates with m(AN)/m(TIN) in third different periods. The chemical oxygen demand (COD) indirectly inhibits the nitrifying bacteria because the DO is depleted in the decomposition of organic matter by heterotrophic bacteria, showing the positive correlation.As the alkalinity can meet the requirement of nitrification in wet season and through the year, it is not restrictive factor. However, it is the second restrictive factor in dry season because of low content of alkalinity inhibiting the growth of nitrifying bacteria.     

Weak indirect effects inherent to nitrogen biogeochemical cycling within anthropogenic ecosystems: A network environ analysis

Indirect effects are assumed to be the major causes of the complexity and stability of ecological networks. The complexity of urban-rural complexes (URCs) could also be attributed to the indirect effects associated with human activities. No studies, however, have quantified the strength of indirect effects in relation to urban biogeochemistry. A network environ analysis (NEA) was used for this study to investigate and compare indirect effects in relation to the nitrogen (N) cycling networks of 22 natural ecosystems and five URCs. Results show that indirect effects were proven to be weak for URC N cycling networks (accounting for only ∼2% of the overall effects measured in natural ecosystems). The weak indirect effects found provide a counterexample for the hypothesis that indirect effects are in fact the dominant components of biogeochemical networks. It also implies that human activity in itself does not always raise the complexity of ecological processes as previously suggested. Weak indirect effects also lead to perturbation fragility for URC N cycles (where the decay rate is greater in comparison to natural ecosystems by a factor of 13). In order to improve the robustness and efficiency of URC biogeochemical cycling, a knockout analysis was carried out. By comparing results after removing single interactions between natural ecosystems and URCs it was found that the loss of indirect effects require cooperative strategies to optimize N cycling networks within URCs.     

城市在用CNG汽车排放研究

通过车载实验,怠速法检测、简易工况法检测数据评价分析等方法,研究了重庆市在用CNG车辆排放情况,比较了CNG车与同类型汽油、柴油车尾气污染物排放情况。研究发现,目前CNG在用车并非绝对的环保汽车,其中在NOx的排放上,CNG车排放高于同类型汽油、柴油车0．03—14倍;在CO、THC的排放上,不同测试工况下CNG汽车表...     

Rank regression analysis of correlated water quality data from South East Queensland

With growing population and fast urbanization in Australia, it is a challenging task to maintain our water quality. It is essential to develop an appropriate statistical methodology in analyzing water quality data in order to draw valid conclusions and hence provide useful advices in water management. This paper is to develop robust rank-based procedures for analyzing nonnormally distributed data collected over time at different sites. To take account of temporal correlations of the observations within sites, we consider the optimally combined estimating functions proposed by Wang and Zhu (Biometrika, 93:459–464, 2006) which leads to more efficient parameter estimation. Furthermore, we apply the induced smoothing method to reduce the computational burden. Smoothing leads to easy calculation of the parameter estimates and their variance-covariance matrix. Analysis of water quality data from Total Iron and Total Cyanophytes shows the differences between the traditional generalized linear mixed models and rank regression models. Our analysis also demonstrates the advantages of the rank regression models for analyzing nonnormal data.