三鑫金铜矿残矿保护性开采方案研究

针对三鑫矿山采用充填采矿法在回采矿房过程中留存大量底柱不能及时回采,后期回采存在安全隐患等问题,对矿山地质条件进行调查,利用Mathew法对矿房稳定性进行研究,结合矿山实际开采计划,对桃花嘴矿区-570～-720四个中段制定了协同回采方案,并利用FLAC3D数值模拟软件对协同回采方案进行可行性探讨.研究表明,为了保持采...     

Response of PM2.5-bound elemental species to emission variations and associated health risk assessment during the COVID-19 pandemic in a coastal megacity

The coronavirus (COVID-19) pandemic is disrupting the world from many aspects. In this study, the impact of emission variations on PM_2.5-bound elemental species and health risks associated to inhalation exposure has been analyzed based on real-time measurements at a remote coastal site in Shanghai during the pandemic. Most trace elemental species decreased significantly and displayed almost no diel peaks during the lockdown. After the lockdown, they rebounded rapidly, of which V and Ni even exceeded the levels before the lockdown, suggesting the recovery of both inland and shipping activities. Five sources were identified based on receptor modeling. Coal combustion accounted for more than 70% of the measured elemental concentrations before and during the lockdown. Shipping emissions, fugitive/mineral dust, and waste incineration all showed elevated contributions after the lockdown. The total non-carcinogenic risk (HQ) for the target elements exceeded the risk threshold for both children and adults with chloride as the predominant species contributing to HQ. Whereas, the total carcinogenic risk (TR) for adults was above the acceptable level and much higher than that for children. Waste incineration was the largest contributor to HQ, while manufacture processing and coal combustion were the main sources of TR. Lockdown control measures were beneficial for lowering the carcinogenic risk while unexpectedly increased the non-carcinogenic risk. From the perspective of health effects, priorities of control measures should be given to waste incineration, manufacture processing, and coal combustion. A balanced way should be reached between both lowering the levels of air pollutants and their health risks.     

国际油污赔偿系统简析

概述国际油污赔偿体系发展状况，在比较旧体制与１９９２ 年议定书适用范围和赔偿请求合理性的基础上，分析ＣＬＣ１９６９ 和ＩＯＰＣ１９７１ 所面临的挑战。阐述废止国际油污赔偿旧体制，加入１９９２ 年议定书紧迫性。     

高海拔矿山井下环境对安全人因指标影响机理研究*

为探明高海拔矿山井下作业环境对安全人因指标影响规律及致因过程,基于安全工程学原理与正交分析理论,借助高海拔环境模拟试验系统,开展单因素及正交复合因素试验,分析安全人因指标与矿山环境参数定量关系,并利用统计分析软件SPSS进行多元回归分析,构建高海拔矿山恶劣环境条件下各安全人因指标动态预测模型,通过与实测数据比对,验证模型可靠性。结果表明:人因指标动态预测模型可以有效预测高海拔矿山井下作业人员安全人因指标变化规律;氧分压、温度、湿度3项环境因素对安全人因指标存在交互影响作用。研究结果可为高海拔矿山安全生产提供理论依据。     

分布式光纤在栈桥监测中的应用分析

为解决传统监测方法在大型基坑支撑结构监测中难度大、效率低、误差大等问题,提出利用分布式传感监测技术对太原火车站调蓄池桁架支撑体系栈桥应力、应变进行监测。基于布里渊光时域反射技术(BOTDR)的测量原理和优点,设计应用一套分布式栈桥监测系统,对栈桥扰动下测试和长期变形监测。结果表明,基于BOTDR技术的栈桥分布式光纤监测系统能够准确地反映支撑体系中栈桥的变形情况,具有显著优势,可满足栈桥变形长期监测和早期安全预警。     

Airborne black carbon variations during the COVID-19 lockdown in the Yangtze River Delta megacities suggest actions to curb global warming

Environmental Chemistry Letters - Airborne black carbon is a strong warming component of the atmosphere. Therefore, curbing black carbon emissions should slow down global warming. The 2019...