2021年夏季新乡市城区臭氧超标日污染特征及敏感性

基于2021年6～8月新乡市市委党校站点观测的挥发性有机物(VOCs)、常规空气污染物和气象参数,采用基于观测的模型(OBM)对臭氧(O₃)超标日的O₃敏感性和前体物的管控策略进行了研究.结果发现,O₃超标日呈现高温、低湿和低压的气象特征.在臭氧超标日,O₃及其前体物的浓度均有上升.臭氧超标日的VOCs最高浓度组分为含氧挥发性有机物(OVOCs)和烷烃,臭氧生成潜势(OFP)和·OH反应性最大的VOCs组分为OVOCs.通过相对增量反应性(RIR)分析,新乡6月O₃超标日臭氧生成处于VOCs控制区,7月和8月处于VOCs和氮氧化物(NO_x)协同控制区,臭氧生成对烯烃和OVOCs最为敏感.6月各前体物的RIR值在一天中会发生变化,但始终保持为VOCs控制区;7月和8月在上午为VOCs控制区,中午为协同控制区,下午分别为协同控制区和NO_x控制区.通过模拟不同前体物削减情景,结果表明削减VOCs始终有利于管控臭氧,而削减NO_x     

露天采矿过程粉尘产生环节及污染治理措施分析研究

粉尘是露天采矿过程的主要污染物之一,露天采矿中粉尘要达到环保要求,需要从生产过程中的凿岩、爆破、装卸、运输、堆存各环节进行污染控制.采用对上述各生产环节中的粉尘产生原理进行分析的方法,找出各个生产环节粉尘的主要产生点,通过对比前人在各个生产环节粉尘控制的研究成果,找出控制粉尘产生的主要影响因素,总结出露天采矿中各个环节上技术经济上最有效的粉尘防治措施,为露天矿山开采污染防治提供系统的解决方案.通过对前人研究成果的总结,汇总形成一套完善的粉尘控制方案.     

基于硫酸自由基的高级氧化技术研究及应用进展

由于硫酸自由基(SO4-.)具有很高的氧化还原电位,过硫酸盐(S2O82-)活化高级氧化技术作为一种新型氧化技术在环境工程领域具有巨大应用潜能。介绍了热活化、光活化、过渡金属离子三种活化过硫酸盐产生SO4-.的方式,在环境保护方面的现状研究与应用进展,主要涉及受有机污染土壤和地下水的修复、难降解有机废水和废气的处理,阐述了SO4-.高级氧化技术处理各种有机污染物的机理,指出了基于SO4-.的高级氧化技术在处理应用中存在的局限性和未来发展方向。     

可吸入颗粒物污染与气象因子的关系

对闸北区空气自动监测站2009年SO2、NO2、PM10的浓度和气象参数变化特征进行研究,可吸入颗粒物的时间变化特征表明,总体上呈现冬春季高、夏秋季低;PM10与降水量、相对湿度、温度呈现一定的负相关性,但与风速的相关性随季节不同而不同,与气压略呈正相关性。对典型日和灰霾日PM10、SO2、NO2以及相应气象因子的特征进行了分析比较。     

航电电源板层间CAF短路失效机理及退化时间分析

目的 掌握CAF失效机理MTTF分析方法,以便于在实际案例中实施工程优化决策,从而降低故障危害风险和寿命周期总费用。方法 以某航电电源母板CAF失效为例,基于CAF失效机理的物理化学变化时间特性模型算法,建立电压、介质间距和MTTF变化关系,以辅助工程优化决策。结果 基于仿真计算数据,形成对特定范围产品的改进和处置决策,从而限制失效危害风险的进一步扩散,降低了产品生命周期维护费用,并提升了客户满意度。结论 掌握装备常见失效机理和采取适宜的应对措施,是持续改进装备可用性、可靠性和环境适应性的必要条件。     

花岗岩类岩体与金矿床成因关系的探讨

花岗岩类岩体与金矿床存在着密切的空间联系，其成因关系一直是矿床学界争论的焦点，目前传统的岩浆热液成因观点仍居统治地位。随着地质资料的积累，高温高压实验技术，尤其是金矿床同位素定年技术的进展，传统观点受到了严峻挑战。成岩成矿的时代与时差、成矿流体的来源和成矿物质的来源等确定金矿床成因类型关键因素的综合研究表明，有密切空间关系的金矿床与花岗岩类岩体之间，在多数情况下两者并无直接的成因联系，金矿床不是岩浆热液成因，而是与大气降水或建造水有关的改造成矿作用的产物。     

Regional crop yield, water consumption and water use efficiency and their responses to climate change in the North China Plain

The North China Plain (NCP) is one of the most important regions for food production in China, with its agricultural system being significantly affected by the undergoing climate change and vulnerable with water stress. In this study, the Vegetation Interface Processes (VIP) model is used to evaluate crop yield, water consumption (ET), and water use efficiency (WUE) of a winter wheat (Triticum aestivum L.)–summer maize (Zea mays L.) double cropping system in the NCP from 1951 to 2006. Their responses to future climate scenarios of 21st century projected by the GCM (HadCM3) with Intergovernmental Panel on Climate Change Special Report on Emission Scenario (IPCC SRES) A2 and B1 emissions are investigated. The results show a rapid enhancement of crop yield in the past 56 years, accompanying with slight increment of ET and noticeable improvement of WUE. There exist spatial patterns of crop yield stemmed mainly from soil quality and irrigation facilities. For climate change impacts, it is found that winter wheat yield will significantly increase with the maximum increment in A2 occurring in 2070s with a value of 19%, whereas the maximum in B1 being 13% in 2060s. Its ET is slightly intensified, which is less than 6%, under both A2 and B1 scenarios, giving rise to the improvement of WUE by 10% and 7% under A2 and B1 scenarios, respectively. Comparatively, summer maize yield will gently decline by 15% for A2 and 12% for B1 scenario, respectively. Its ET is obviously increasing since 2050s with over 10% relative change, leading to a lower WUE with more than 25% relative change under both scenarios in 2090s. Therefore, possible adaptation countermeasures should be developed to mitigate the negative effects of climate change for the sustainable development of agro-ecosystems in the NCP.     

Investigation of titanium liquid/gas diffusion layers in proton exchange membrane electrolyzer cells

In a proton exchange membrane electrolyzer cell (PEMEC), liquid/gas diffusion layer (LGDL) is expected to transport electrons, heat, and reactants/products to and from the catalyst layer with minimum voltage, current, thermal, interfacial, and fluidic losses. In addition, carbon materials, which are typically used in PEM fuel cells (PEMFCs), are unsuitable in PEMECs due to the high ohmic potential and highly oxidative environment of the oxygen electrode. In this study, a set of titanium gas diffusion layers with different thicknesses and porosities are designed and examined coupled with the development of a robust titanium bipolar plate. It has been found that the performance of electrolyzer improves along with a decrease in thickness or porosity of the anode LGDL of titanium woven meshes. The ohmic resistance of anode LGDL and contact resistance between anode LGDL and the anode catalyst play dominant roles in electrolyzer performance, and better performance can be obtained by reducing ohmic resistance. Thin titanium LGDLs with straight-through pores and optimal pore morphologies are recommended for the future developments of low-cost LGDLs with minimum ohmic/transport losses.     

内蒙古自治区“十二五”规划循环经济发展水平预测评估

内蒙古自治区“十二五”规划提出要大力发展循环经济,以煤炭、电力、化工、冶金、建材等行业为重点,规划实施将有利于实现内蒙古自治区循环性社会体系的构建,促进循环经济水平和质量的全面提升.在优化水平下2015年内蒙古自治区循环经济发展综合指数为2.03,在优化水平条件下内蒙古循环经济发展水平将有较快的提升.     

Effects of typical algae species (Aphanizomenon flosaquae and Microcystis aeruginosa) on photoreduction of Hg2+ in water body

Photoreduction characteristics of divalent inorganic mercury(Hg~(2+)) in the presence of specific algae species are still not well known. Laboratory experiments were conducted in the present study to identify the effects of different concentrations of living/dead algae species, including Aphanizomenon flosaquae(AF) and Microcystis aeruginosa(MA), on the photoreduction rate of Hg~(2+)under various light conditions. The experimental results showed that percentage reduction of Hg~(2+)was significantly influenced by radiation wavelengths, and dramatically decreased with the presence of algae. The highest percentage reduction of Hg~(2+)was induced by UV-A, followed by UV-B, visible light and dark for both living and dead AF, and the order was dark UV-A UV-B visible light for both living and dead MA. There were two aspects, i.e., energy and attenuation rate of light radiation and excrementitious generated from algae metabolisms, were involved in the processes of Hg~(2+)photoreduction with the presence of algae under different light conditions. The percentage reduction of Hg~(2+)decreased from 15% to 11% when living and dead AF concentrations increased by 10 times(from 106 to 105 cells/mL), and decreased from 11% to ～ 9% in the case of living and dead MA increased. Algae can adsorb Hg~(2+)and decrease the concentration of free Hg~(2+), thus inhibiting Hg~(2+)photoreduction, especially under the conditions with high concentrations of algae. No significant differences were found in percentage reduction of Hg~(2+)between living and dead treatments of algae species.The results are of great importance for understanding the role of algae in Hg~(2+)photoreduction.