涂层石墨管原子吸收法测定水中痕量铍

比较了多种涂层金属和基体改进剂对测定水中铍的影响,建立了涂镧石墨管结合基体改进剂(磷酸二氢铵)测定水中痕量铍的方法。该方法最低检出限为0.037 μg/L,相对标准偏差为7.4%,回收率为98%～106%。      

四溴双酚A和镉复合污染对不同生物体的安全阈值

以赤子爱胜蚓（Eisenia fetida）、斑马鱼（Zebrafish）作为受试生物,进行急性毒性试验,死亡率、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）为效应指标,采用基准剂量（BMD）法推导四溴双酚A （TBBPA）和镉（Cd）单一及联合暴露对不同生物体的安全阈值.结果表明,在本研究的试验剂量范围内,蚯蚓、斑马鱼TBBPA、Cd暴露剂量与死亡率、SOD、CAT活性效应指标存在明显剂量-效应关系.单一暴露下,CAT、SOD活性指标最敏感,蚯蚓和斑马鱼的TBBPA安全阈值分别为0.95,0.44mg/L,Cd安全阈值分别为71.17,0.42mg/L.联合暴露下安全阈值小于单一暴露.蚯蚓、斑马鱼TBBPA安全阈值分别为0.33,0.024mg/L,Cd为6.45,0.176mg/L.     

Progress in quantitative research on the relationship between atmospheric oxidation and air quality

Atmospheric oxidizing capacity (AOC) is an essential driving force of troposphere chemistry and self-cleaning, but the definition of AOC and its quantitative representation remain uncertain. Driven by national demand for air pollution control in recent years, Chinese scholars have carried out studies on theories of atmospheric chemistry and have made considerable progress in AOC research. This paper will give a brief review of these developments. First, AOC indexes were established that represent apparent atmospheric oxidizing ability (AOIe) and potential atmospheric oxidizing ability (AOIp) based on aspects of macrothermodynamics and microdynamics, respectively. A closed study refined the quantitative contributions of heterogeneous chemistry to AOC in Beijing, and these AOC methods were further applied in Beijing-Tianjin-Hebei and key areas across the country. In addition, the detection of ground or vertical profiles for atmospheric OH·, HO₂·, NO₃· radicals and reservoir molecules can now be obtained with domestic instruments in diverse environments. Moreover, laboratory smoke chamber simulations revealed heterogeneous processes involving reactions of O₃ and NO₂, which are typical oxidants in the surface/interface atmosphere, and the evolutionary and budgetary implications of atmospheric oxidants reacting under multispecies, multiphase and multi-interface conditions were obtained. Finally, based on the GRAPES-CUACE adjoint model improved by Chinese scholars, simulations of key substances affecting atmospheric oxidation and secondary organic and inorganic aerosol formation have been optimized. Normalized numerical simulations of AOIe and AOIp were performed, and regional coordination of AOC was adjusted. An optimized plan for controlling O₃ and PM_2.5 was analyzed by scenario simulation.     

VOC emission caps constrained by air quality targets based on response surface model: A case study in the Pearl River Delta Region, China

Because of the recent growth in ground-level ozone and increased emission of volatile organic compounds (VOCs), VOC emission control has become a major concern in China. In response, emission caps to control VOC have been stipulated in recent policies, but few of them were constrained by the co-control target of PM_2.5 and ozone, and discussed the factor that influence the emission cap formulation. Herein, we proposed a framework for quantification of VOC emission caps constrained by targets for PM_2.5 and ozone via a new response surface modeling (RSM) technique, achieving 50% computational cost savings of the quantification. In the Pearl River Delta (PRD) region, the VOC emission caps constrained by air quality targets varied greatly with the NO_x emission reduction level. If control measures in the surrounding areas of the PRD region were not considered, there could be two feasible strategies for VOC emission caps to meet air quality targets (160 µg/m³ for the maximum 8-hr-average 90th-percentile (MDA8-90%) ozone and 25 µg/m³ for the annual average of PM_2.5): a moderate VOC emission cap with <20% NOx emission reductions or a notable VOC emission cap with >60% NO_x emission reductions. If the ozone concentration target were reduced to 155 µg/m³, deep NO_x emission reductions is the only feasible ozone control measure in PRD. Optimization of seasonal VOC emission caps based on the Monte Carlo simulation could allow us to gain higher ozone benefits or greater VOC emission reductions. If VOC emissions were further reduced in autumn, MDA8-90% ozone could be lowered by 0.3-1.5 µg/m³, equaling the ozone benefits of 10% VOC emission reduction measures. The method for VOC emission cap quantification and optimization proposed in this study could provide scientific guidance for coordinated control of regional PM_2.5 and O₃ pollution in China.     

The research of below-cloud scavengingof rainwater in Guilin City

Ｔｈｅｒｅｓｅａｒｃｈｏｆｂｅｌｏｗ－ｃｌｏｕｄｓｃａｖｅｎｇｉｎｇｏｆｒａｉｎｗａｔｅｒｉｎＧｕｉｌｉｎＣｉｔｙＢａｉＹｕｈｕａ；ＹａｏＲｏｎｇｋｕｉ；ＬｉＸｉｎ；ＴａｎｇＸｉａｏｙａｎ（ＴｈｅＤｅｐａｒｔｍｅｎｔｏｆＴｅｃｈｎｉｃａｌＰｈｙｓｉｅ...     

烟气中SO2/NOx同时吸收催化脱除的研究

根据同时脱硫脱硝的要求,对以ＣＵＯ为主要活性组分催化剂的制备和反应过程进行研究,活性测试的结果表明,催化剂的最佳活化温度和活化时间分别为４５０℃和２ｈ。当反应温度为４００℃,空间速度为２×１０＾４ｈ＾－１以及ＣｕＳＯ４／ＣｕＯ摩尔比和Ｃｕ／Ｓ分别保持在１．４６和０．８３以上时,ＳＯ２和ＮＯｘ的脱除率可达９０％以上。     

大型车车身覆盖件冲压成形特征分析及选材研究

为满足大型车身覆盖件冲压成形要求并实现钢板与零件的对路供应 ,必须在深入解析零件成形特征的基础上 ,确定高应变部位的成形敏感材料参数。在材料力学性能测试和成形极限分析的基础上 ,对侧围外板的冲压成形特征和成形敏感参数进行了分析。结果表明 :侧围外板零件高应变部位的变形方式为胀形 深拉延变形 ,n值和r值为影响侧围外板零件成形的主要材料敏感参数     

北京气象塔夏季大气臭氧观测研究

2000年夏季7～8月,以北京325m气象塔为观测平台,分别在8,120,280m高度上进行了大气污染物臭氧(O₃)及其前体物氮氧化物(NO_x)和气象要素加强期的同步观测.对观测资料的分析表明,边界层内存在明显的臭氧浓度垂直差异;低层臭氧浓度呈明显的日变化,且昼夜振幅较大;对O₃浓度与NO₂/NO的比值作线性拟合分析发现,白天(10:00～16:00)O₃浓度与[NO₂/NO]的比值成线性关系,即达到光化学稳定态,但受气象背景场影响较大.     

基于人工神经网络模型预测ABR反应器处理效率

ABR反应器的处理效率受多方面的因素影响，本文通过BP人工神经网络，利用ABR反应器进水CODcr浓度、容积负荷、温度、稳定运行时间四个参数对其反应器处理效率进行预测。结果表明，BP人工神经网络可较好的用于ABR反应器处理效率的预测，具有较高的精度，在实际生产中，可以运用人工神经网络，对ABR反应器的运行参数进行调整，使之达到最优化的运行状态。     

磷元素在饮用水生物处理中的限制因子作用

应用细菌生长潜力(BGP)法,考察了磷元素在淮河流域某地面水厂饮用水生物处理工艺中的限制因子作用原水添加50μg·L^-1KH₂PO₄-P后,BGP可以提高54%,添加其它无机元素和添加磷元素对BGP的影响没有显著差异;原水添加20mg·L^-1C₆H₁₂O₆对BGP的影响要小于添加50μg·L^-1KH₂PO₄-P的影响;原水添加磷后生物滤池对COD_Mn的去除率比对照生物滤池提高了7.5%,其出水明显表现为碳限制型,对照生物滤池出水则为磷限制型.结果说明磷元素是该水厂饮用水生物处理的限制因子,且限制作用强于碳元素,可以通过外加磷源的方法提高饮用水生物处理工艺对有机物的去除效率.