发动机燃料组分生烟特性的研究

本文采用火焰高度测定仪系统地评价了构成发动机燃料的单体烃和单体醇的生烟特性,提出并应用碳烟生成的烃正离子概念解释了单体烃和单体醇的生烟规律,为正确调整发动机燃料构成提供了实践基础,也为研究和开发消烟助燃剂奠定了理论基础。     

杭州秋季大气VOCs变化特征及化学反应活性研究

2017年9月1日至11月30日采用Syntech Spectras GC955在线气相色谱仪对杭州市不同功能区大气环境中的挥发性有机化合物(VOCs)进行了在线连续监测,分析了不同功能区VOCs及各组分的体积分数、日变化规律及大气化学反应活性。结果显示,下沙周边工业区总VOCs浓度整体高于朝晖周边居民区,其中夜间更为显著。烷烃和芳香烃浓度在夜间时段工业区较居民区高得更为明显,其中芳香烃组分表现尤为突出,2个功能区烯烃体积分数相差不大。杭州市主要VOCs体积分数总体上在国内处于中间水平。不同功能区烷烃和芳香烃均呈现夜间浓度高于白天的日变化特征,居民区各VOCs组分日变化基本呈现双峰结构,工业区烷烃和芳香烃体积分数日变化呈现单峰结构,烯烃体积分数没有明显的日变化特征。不同功能区中芳香烃对臭氧生成潜势贡献最大,烯烃次之,烷烃贡献最小。下沙周边工业区大气化学活性(尤其是芳香烃组分)较朝晖周边居民区强。同种VOCs物质在不同功能区对臭氧生成潜势的贡献大小不同,但关键贡献物质均为低碳烷烃、低碳烯烃及苯系物。     

杭州市大气VOCs浓度特征及其化学活性研究

2018年4月至2019年3月对杭州市城区大气中117种挥发性有机物(VOCs)开展了为期一年的手工采样观测,分析了VOCs各组分的浓度特征、臭氧生成潜势(OFP)和二次有机气溶胶(SOA)生成潜势。结果显示,观测期杭州市大气VOCs体积分数均值为(56.72±29.56)×10^-9,含氧挥发性有机物(OVOCs)、烷烃和卤代烃是其主要组分,分别占33.86%、30.70%、15.73%。VOCs体积分数前10位的物种为丙烷、甲醛、异丁烷、乙烷、乙酸乙酯、二氯甲烷、正丁烷、丙酮、甲苯和1,2-二氯乙烷。杭州市VOCs的OFP为135.18×10^-9,各VOCs组分的OFP贡献为OVOCs(45%)>芳香烃(22%)>烯烃和炔烃(21%)>烷烃(11%)>卤代烃(1%),其中甲醛、乙烯和乙醛是OFP主要贡献者。SOA生成潜势为1.64μg/m³,芳香烃是最重要的SOA前体物。SOA生成潜势最大的5种VOCs物种为甲苯、对/间二甲苯、乙苯、邻二甲苯和苯,因此控制来自机动车尾气和溶剂使用过程中产生的VO...     

混凝-气浮控制三卤甲烷生成势的研究

研究了混凝一气浮工艺对不同分子量区间三卤甲烷生成势（trihalomethanes formation potential,THMFP）的去除效果及絮体形态对THMFP去除效果的影响。结果表明,混凝一气浮工艺以去除大分子量区间THMFP为主,对小分子量区间THMFP的去除效果较差。UV254值与THMFP值的线性相关系数为0．9449,UV254值可以较好地反映THMFP的含量。絮体的分形维数为1．17～1．2时,孔隙率较大,可增加絮体对THMFP的活性吸附空间,且絮体相对密度较小,可增强同向絮凝作用,增加絮体和THMFP的接触概率,有利于气浮对THMFP的去除。     

Cytotoxicity estimation of ionic liquids based on their effective structural features

Cytotoxicity of a diverse set of 227 ionic liquids (taken from UFT/Merck Ionic Liquids Biological Effects Database) containing 94 imidazolium, 53 pyridinium, 23 pyrrolidinium, 22 ammonium, 15 piperidinium, 10 morpholinium, 5 phosphanium, and 5 quinolinium cations in combination with 25 different types of anions to Leukemia Rat Cell Line (IPC-81) was estimated from their structural parameters using quantitative structure - toxicity relationship “QSTR” methodology. Linear and nonlinear models were developed using genetic algorithm (GA), multiple linear regressions (MLR) and multilayer perceptron neural network (MLP NN) approaches. Robustness and reliability of the constructed models were evaluated through internal and external validation methods. Furthermore, chemical applicability domain was determined via leverage approach. In this work, it was revealed that the cationic moieties make the major contribution to cytotoxicity and the anionic parts play a secondary role in cytotoxicity of the ionic liquids studied here. Structural information represented in this work, can be used for a rational design of safer ILs.     

啤酒酿造用地下水模糊聚类分析

采用沈阳某啤酒厂１９９４年全年地下水水质监测数据，对啤酒酿造地下水井点和部分监测项目进行模糊聚类分析，并对结果进行了评述。     

Environmental release of dioxins from reservoir sources during beach nourishment programs

In late 1990s, USEPA/FDA made an important connection regarding the presence of elevated levels of dioxins (e.g., 1500 ng kg⁻¹ TEQ) in ball clays mined in Mississippi (USA) from a geological deposit dated to ∼40 million years (Mississippi Embayment) that stretches over several states (northern part of Mississippi to Kentucky) and levels of dioxins in selected animal food sources. Following a recent beach nourishment program along the mid-Atlantic coast of the US, a number of dark gray, blue tinted nuggets of varying sizes were found on beach strands and near the shoreline. Using the presence of these balls of clay (shape, color, and knowledge regarding their use in pottery) on the beach, together with our direct experience analyzing ball clays for dioxins, we made a possible association between these clays and elevated dioxins. Concerns regarding the potential of nourishment programs to cause severe damage to our beaches drove us to test the dioxin content of nourishment exposed clays. A number of the nuggets, along with freshly dredged and deposited sand (collected the morning after nourishment) with the same coloration, and others (sun-bleached), collected approximately 2 weeks after the completion of the nourishment efforts, were analyzed for the presence of PCDD/Fs, PCBs, and selected semi-volatile chlorinated organics. The clay PCDD/F WHO2005-TEQs (dry weight; ND = DL; EMPC = EMPC) ranged from 0.41 to 5.78 ng kg⁻¹ with an average of 2.64 ng kg⁻¹, whereas the sand sample’s TEQs ranged from 0.18 to 0.31 ng kg⁻¹ PCDD/F WHO-2005, with an average of 0.22 ng kg⁻¹. The average total tetra- through octachlorinated dibenzo-p-dioxin concentration was 2700 ng kg⁻¹ (with a maximum of 5800 ng kg⁻¹) for the clays and 8.5 ng kg⁻¹ (with a maximum of 16.8 ng kg⁻¹) for the sand samples. The congener 2,3,7,8-TCDD (TEF = 1) was detected in half of the clay samples (0.11-0.77 ng kg⁻¹). All of the clay and sand samples displayed an unambiguous and dominating 1,4,6,9-chlorination pattern across homolog groups. No other chlorinated aromatics were detected above background levels. The observations, along with the absence or an extremely low level of polychlorinated dibenzofurans, together with the mineralogical analysis, supports the conclusion that off-shore dredging activities are reaching reservoir sources containing dioxin-tainted, smectic/kaolinite clay minerals. Subsequent beach erosion provides additional environmental releases over time, as buried balls of clay from previous nourishment efforts become exposed.     

石家庄夏季典型时段臭氧污染特征及来源解析

在石家庄臭氧(O₃)污染较重的7月,开展连续10 d(2018年7月6—15日),8次/d的加密监测,获得大气挥发性有机物(VOCs)苏玛罐样品数据及O₃在线监测数据,分析了采样期间O₃污染特征、VOCs组成及O₃生成潜势(OFP)特征,并对VOCs来源进行了研究。结果表明,采样期间O₃-3 h浓度最高为243 μg/m³,与相对湿度存在明显的反相关关系,与温度和风速存在良好的正相关关系。VOCs平均体积分数为(75.28±5.81)×10-9,各组分浓度所占比例为OVOCs>烷烃>卤代烃>烯炔烃>芳香烃>其他组分。各类VOCs中,OVOCs对OFP的贡献最大,占64.12%。作为光化学反应的中间产物,OVOCs的一次来源较少,表明二次污染物对石家庄大气O₃生成有重要贡献。从具体组分来看,OFP值排名前十的组分以OVOCs为主,其中最高的为甲基丙烯酸甲酯。采样期间,VOCs一次来源主要为汽油车和柴油车尾气排放,贡献率分别为38%与32%;溶剂使用、汽油挥发、生物排放分别占13%、11%、6%。VOCs主要受本地排放影响。     

超临界锅炉中T23管内氧化皮的生成及剥落机理研究

通过对超临界锅炉中T23管内氧化皮检查和剥落物取样,利用能量色散谱仪和X射线衍射仪对其进行试验研究。分析了T23管内氧化皮的成分和结构特征,阐述了氧化皮生成和剥落机理及其影响因素,并提出了防治氧化皮大面积脱落的措施,为减轻超临界锅炉高温受热面管内氧化皮的生成,避免超温爆管等提供了一定的基础。     

海面散射对舰船编队电磁干扰影响的数学模型

从舰船编队的抗干扰需求出发,从海面散射对耦合途径的影响、海面散射路径和雷达波在海面上的反射特性3个方面建立起较为全面而系统的数学模型。首先结合镜像理论获取了海面散射的菲涅尔区,然后结合传统的＂四路径＂模型分析出舰船编队间电磁干扰的主要路径,最后结合海面的分形几何特性和海水的介电特性,推导出典型海况下海面的散射系数表达式。建立的数学模型不仅可以为舰船编队间电磁干扰的计算提供有力工具,还可以对遥感、海洋探测等多项技术予以理论支撑。