标准类别指数法在地表水环境质量评价中的应用

在确定水体主要污染物的基础上，以相应水体主要污染物项目为评价项目，以地表水环境质量标准的类别分级为依据，应用模糊数学理论对地表水环境质量或污染程度予以分级。能客观、直观地反映相应地表水体环境质量或污染程度，计算过程简便，是一种可采纳的实用水质评价方法。     

工程对环境影响系统分析中有关二次影响问题的探讨

就水电工程对生态与环境二次影响问题的系统分析,提出一种便于应用的交互矩阵方法,并讨论了二次影响程度如何在度量规范中进行追加计算。     

Review of sustainability terms and their definitions

Terminology in the field of sustainable development is becoming increasingly important because the number of terms continues to increase along with the rapid increase in awareness of the importance of sustainability. Various definitions of terms are used by different authors and organizations, for example, green chemistry, cleaner production, pollution prevention, etc. The importance of this topic has stimulated research into the problems of clarifying ambiguity and classifying terms used in the sustainability field. This paper provides results of the literature survey and summarizes the definitions of the terms, focusing on the environmental engineering field. In some cases, it proposes an improved definition. A hierarchical classification of the terms and their relationships has been based on a layer format that is presented graphically.     

基于Ⅰ-Ⅱ复合型裂纹破坏模式的条带矿柱破坏宽度研究

采用条带法进行地下开采时,条带矿柱的裂纹扩展导致了矿柱的最终破坏,且裂纹多表现为Ⅰ型裂纹与Ⅱ型裂纹复合扩展破坏特征。根据采场矿柱受力条件,确定条带矿柱受两侧采场空区影响时矿柱内Ⅰ-П复合型裂纹尖端的Westergaard应力函数,采用HoekBrown强度准则计算采场作业面围岩破坏区的边界条件,建立了矿柱破坏宽度计算模型。以上横山页岩矿床为研究对象,采用物理相似模拟试验,模拟条带法回采某盘区3个试验区段,利用DIP法分析受地应力及回采扰动作用下矿柱的裂纹发育特征,验证模型的有效性。结果表明,条带及其条带矿柱均为15 m等设计参数条件下,计算模型矿柱破坏宽度理论值分别为17.66 m、15.56 m和10.28 m,试验模拟结果分别为完全大于15 m、约为15 m和10.5~11.0 m,试验结果与依据模型计算的理论值相近。     

基于PCA-BP神经网络的多股铜导线 熔痕定量金相识别方法研究

为实现火灾现场中多股铜导线熔痕的自动识别,采用主成分分析(PCA)和反向传播(BP)神经网络算法对四种多股铜导线熔痕(一次短路熔痕、二次短路熔痕、过负荷熔痕和火烧熔痕)的金相组织进行了识别研究。利用Image-Pro Plus 6.0和Axio-Imaging软件获取每种熔痕30组17维金相组织参数数据,采用PCA对四种熔痕共120组数据降维,获得前6个主成分得分矩阵,建立具有6个输入层节点,10个隐层节点和4个输出节点的神经网络模式识别模型。随机抽取每种熔痕的20组样品的主成分得分矩阵作为训练集,将每种熔痕的剩余10组主成分得分为测试数据,输入最终训练完成的模型进行识别,其识别准确率达到92.5%。实验结果表明采用PCA+BP神经网络的算法,可以较好地实现多股铜导线熔痕识别,为火灾物证鉴定工作提供了有力的工具。     

Human and organizational factors in Chinese hazardous chemical accidents: a case study of the ‘8.12’ Tianjin Port fire and explosion using the HFACS-HC

Human and organizational factors have been proven to be the prime causes of Chinese hazardous chemical accidents (HCAs). A modified version of the Human Factors Analysis and Classification System (HFACS), namely the HFACS-Hazardous Chemicals (HC), was developed to identify the human factors involved in Chinese HCAs. The ‘8.12’ Tianjin Port fire and explosion, the costliest HCA in recent years, was reanalyzed using this framework, and the results were compared with the official accident inquiry report to determine their differences related to the identification of human and organizational factors. The study revealed that interacting human factors from different levels in Ruihai Company led to this catastrophe, and the inquiry report had limitations in the identification of human factors and the guidance for similar accident prevention. This study showed the applicability of the HFACS-HC in HCA analyses as well as the necessity to recommend this approach for future HCA investigations.     

Predicting categories of drugs used by suspected drug-impaired drivers using the Drug Evaluation and Classification Program tests

Objective: The purpose of this study was to statistically determine which combination(s) of drug-related signs and symptoms from the Drug Evaluation and Classification (DEC) protocol best predict the drug category used by the suspected drug-impaired driver.

Methods: Data from 1,512 completed DEC evaluations of suspected impaired drivers subsequently found to have ingested central nervous system (CNS) depressants, CNS stimulants, narcotic analgesics, and cannabis were analyzed using a multinomial logistic regression procedure. A set of evaluations completed on drug-free subjects was also included. The relative importance of clinical, behavioral, and observational measures in predicting drug categories responsible for impairment was also examined.

Results: Thirteen drug-related indicators were found to significantly contribute to the prediction of drug category, including being under the care of a doctor or dentist, condition of the eyes, condition of the eyelids, mean pulse rate, assessment of horizontal gaze nystagmus (HGN), convergence, performance on the One Leg Stand (OLS) Test, eyelid tremors, pupil size in darkness, reaction to light, presence of visible injection sites, systolic blood pressure, and muscle tone. Indicators related to the appearance and physiological response of the eye contributed the most to the prediction of drug category, followed closely by clinical indicators and performance on the psychophysical tests.

Conclusions: The findings from this study suggest that drug recognition experts (DREs) should be careful to review a set of key signs and symptoms when determining the category of drug used by suspected drug-impaired drivers. Drug use indicators related to the appearance and physiological response of the eye were found to contribute the most to the prediction of the drug category responsible for the impairment. These results could help form the basis of a core set of indicators that DREs could initially consult to form their opinion of drug influence. This in turn may enhance the validity, effectiveness, and efficiency of drug detection and identification by DREs and lead to a more effective and efficient DEC program, improved enforcement of drug-impaired driving, and greater acceptance of the DEC program by the courts.     

高层RC框架结构基于成本-效益准则的优化设计研究(Ⅱ)——应用

根据作者先前提出的优化模型及基于成本-效益准则的优化设计流程,以多目标遗传算法为搜索引擎,运用MATLAB语言开发了高层RC框架结构基于成本-效益准则的自动优化程序。研究结果表明,程序所产生的设计方案具有多样性、可选择性、业主主动参与性及可依靠经验等特点。     

基于综合评判模型的煤与瓦斯突出危险程度预测

针对某些矿井出现的"低指标"突出现象,提出一种新的综合评判模型,用于煤与瓦斯突出危险程度预测。选取鉴定煤与瓦斯突出的4个单项指标临界值作为参考点,建立煤与瓦斯突出危险性预测综合评判准则。当评判距离Ri属于[0,1],判断突出强度;当Ri属于[-1,0],判断突出危险可能性,量化了突出强度及可能突出的危险程度,并划分突出强度、突出危险可能性等级。利用模型对淮南矿突出程度进行预测,预测结果与实际吻合,实现了定性语言与定量数据相结合的突出预测,为煤与瓦斯突出提供了一种新的预测方法。