Data mining applications in evaluating mine ventilation system

A mine’s ventilation system is an important component of an underground mining system. It provides a sufficient quantity of air to maintain suitable working environment. Therefore, the status of mine ventilation should be tracked and monitored as a timely matter. Based on former findings and in-depth analysis of mine ventilation systems, a proper early warning model is proposed in this paper for such considerations to improve the mine ventilation safety. The model itself is comprised of two sub-models, and two data mining techniques are used to assist in building each sub-model. One is the optimal indexes selection model which applies the Rough Set theory (RS) to assist the selection of best ventilation indexes. The other is the risk evaluation model based on the Support Vector Machine (SVM) to classify the risk ranks for the mine ventilation system. Testing cases have been used to demonstrate the applicability of this integrated model.     

综合类生态工业园区循环经济模式构建

在分析综合性生态工业园区特点的基础上,从企业、园区和循环社会3个层面,构建综合类生态工业园区循环经济发展模式。以安塞工业园区为例,构建了工业园循环经济产业链系统,提出了综合类生态工业园区循环经济模式建设的具体途径。     

臭氧高级氧化协同下的造纸废水深度处理小试研究

采用"臭氧高级氧化+固定化微生物反应器"工艺对造纸废水进行深度处理小型试验,处理能力为2.4m3/d。结果表明,在系统进水COD为280～350mg/L的情况下,出水COD在50 mg/L以下,最低为42 mg/L,去除率保持在80%以上,最高达85%,色度去除率为70%～80%。出水COD满足GB 3544—2008《制浆造纸工业水污染物排放标准》要求。     

Methods to determine the mine gas explosibility – An overview

Mine gas explosions present a serious safety threat in the worldwide mining industry. Since the beginning of mining, many coal miners have been killed due to the explosions. Accordingly, on a regular basis, mine operators should get air samples from the underground atmosphere. At the same time, monitoring and tracking the explosibility of the air sample should be done as a timely matter to avoid any potential explosions. All these works can provide very important information to assist the mine operators to well understand the mine atmospheric status and its trends. In additional, when facing the coal spontaneous combustion, mine fire events, or other chemical reactions related mine accidents, determination of explosibility is a definitely significant work for the safety of miners and mine rescue personnel especially when planning and implementing any mine rescue strategies. For many years, mining engineers and researchers have developed a number of methods for assessing the explosibility of the air–gas-mixture. Their research results provide a baseline for judgments of the mine gas explosibility and in determining the extent of change. In this paper, main popular and typical methods used in mining industry to determine the mine gas explosibility are introduced and reviewed. Case demonstrations for each method are also shown and can be used to instruct readers to understand how to apply them. Finally, a brief discussion about the current methods is presented and some preliminary suggestions are also listed for the further improvements in the future research.     

高强再生混凝土柱大偏压性能试验研究

为了解再生粗骨料高强混凝土柱的压弯力学性能,进行了4根大尺寸钢筋混凝土柱大偏心受压重复荷载试验,包括方形与圆形两种截面柱,方形截面边长为600 mm×600 mm,圆形截面直径为675mm。研究变化参数为再生粗骨料取代率。在试验基础上,分析了其破坏特征、承载力、刚度及截面应变发展规律。结果表明,不同截面形式的再生粗骨料高强混凝土柱,其大偏压破坏过程、破坏形态、刚度退化、截面应变发展规律与普通混凝土柱的没有明显区别。参照现行混凝土结构设计规范的相关设计公式计算其极限承载力,计算结果与试验结果符合良好,计算精度能够满足工程要求。     

浑善达克沙地末次冰期晚期到全新世的环境转型

对浑善达克沙地7个晚更新世末期风成砂－全新世黑色砂质土壤序列剖面进行了光释光年代测试,并对26个野外风成剖面进行了考察及粒度、磁化率测量。通过对黑色砂质土壤层之下砂层粒度、磁化率指标分析,砂层OSL测年,确定了末次冰期晚期浑善达克沙地活动砂丘分布范围。目前浑善达克沙地为砂质草原,主要为固定砂丘,面积约52000 km2...     

Dose–response relationships between urinary cobalt concentrations and obesity,insulin resistance,and metabolic-related disorders in the general population

Environmental Science and Pollution Research - Excessive cobalt exposure has been shown to induce various adverse health effects in animal and human toxicity studies. However, the relationships...     

某水源水库嗅味来源及潜在产嗅藻分布特征解析

华东地区某水源水库近年来出现季节性嗅味问题。为解析嗅味产生来源及其成因,于2018年4月至2019年12月对该水库上游以及库内水体进行长期监测。监测结果表明,2-甲基异莰醇(2-MIB)是主要的土霉味致嗅物质,伪鱼腥藻是该水库潜在产嗅藻种,且其主要为外源输入。相关性分析结果表明,伪鱼腥藻的生长与水温及水下光照(透明度、浊度)等有关。为进一步解析水下光照因素驱动下伪鱼腥藻在水库水体中的分布特征,在水库高嗅期间开展了72 h连续监测,重点分析了伪鱼腥藻昼夜与垂向分布特征。结果表明,在08:00,伪鱼腥藻往表层迁移,在10:00—14:00,表层密度达到最高值,白天在水体中呈现明显的垂向迁移特征,而夜晚在水体中各层的分布无明显变化,这进一步说明水下光照对伪鱼腥藻生长的重要性。以上结果进一步提升了对实际水体中伪鱼腥藻分布规律的认识,可为水源地中伪鱼腥藻导致的嗅味问题提供借鉴。     

酒石酸强化重金属复合污染模拟土壤电动修复过程及机理分析

为提高电动修复重金属复合污染土壤的效率,通过配制重金属复合污染模拟土壤,构建电动修复实验装置,利用2因素完全随机实验设计研究了酒石酸浓度和时间对重金属去除效果的影响;采用BCR法对土壤金属赋存形态进行了分析表征。结果表明：与对照相比,以酒石酸为电解液显著提高了重金属的去除率;重金属去除率受酒石酸浓度和修复时间影响显著;以0.05 mol·L⁻¹酒石酸为电解液修复120 h后,重金属去除效果最好,重金属总去除率为86.15%,Cu²⁺、Mn²⁺、Cd²⁺、Pb²⁺、Zn²⁺的去除率分别为75.67%、98.11%、85.1%、70.75%和90.9%。BCR分析表明,酒石酸有助于提高土壤中弱酸提取态重金属含量,提高了重金属的迁移性能,从而有利于电动修复过程。     

吡啶缺氧生物降解特性及其降解产物

吡啶是焦化废水中较为典型的含氮杂环化合物,难以被生物降解。通过研究吡啶的缺氧生物降解特性,并对其降解产物进行鉴定,以期为实际生产提供理论依据和为今后进一步研究做出铺垫。结果表明,吡啶在本实验条件下的最佳降解浓度为80 mg·L-1,对于后期测定降解中间产物,该浓度和其降解周期均较为合适;戊二醛为吡啶在缺氧反硝化降解过程中的一个重要中间产物,其浓度在反应进行32 h时积累达到最大值。在上述实验基础上,在底物中加入40 mg·L-1苯酚,其对吡啶的降解产生抑制作用,戊二醛浓度最大值出现在反应进行40 h处,由此推断苯酚对吡啶降解的抑制作用可能产生于吡啶开环脱氮阶段。