空气中总悬浮颗粒物的X射线衍射定性分析研究

以天津市环境监测中心采集的空气中总悬浮颗粒物（ＴＳＰ）膜（９７１０１２号）为样品,使用日本理学Ｄ／ｍａｘＲＡＸ射线衍射仪对其进行化合物定性分析,并介绍样品的采集与制样方法、仪器测试条件。最后通过ＪＣＰＤＳＩＣＤＤ（国际粉末衍射数据中心）标准数据库检索出该样品所含的全部化合物     

沈阳市大气可吸入颗粒物水溶性组分的因子分析

选取沈阳市6个监测点位,采集2005年冬、春、夏、秋大气可吸入颗粒物样本。用安捷伦7500型电感耦合等离子体质谱仪分析PM10中19种水溶性组分。用因子分析法分析了沈阳市大气可吸入颗粒物水溶性组分的来源。     

空气细颗粒物(PM2.5)污染特征及其毒性机制的研究进展

细颗粒物(PM2.5)是指空气动力学直径≤2.5μm的颗粒物,其表面吸附大量的有毒有害物质,并可通过呼吸沉积在肺泡,甚至可通过肺换气到达其他器官.由于细颗粒物的重要性,美国EPA已经于1997年颁布了细颗粒物的空气质量标准,年均值为0.015mg/m3,日均值为0.065mg/m3,然而我国至今仍未制定细颗粒物空气质量标准.颗粒物上吸附的化学组分主要可分成自然来源及燃煤或燃油等人为污染来源两大类,特别是来自工业性和居住区燃煤及汽车燃油尾气.空气细颗粒物污染表现为形态各异、成分复杂等特征.细颗粒物有明显的毒性作用,可引起机体呼吸系统、免疫系统等较为广泛的损害.细颗粒物与心肺疾病密切相关,如增加入院率、急诊次数、呼吸疾病及症状增加、肺功能下降,甚至于过早死亡.简要概述了细颗粒物的污染特征及其毒性机制研究进展.     

厦门水库水体颗粒物分布特征及其与环境因子的关系研究

研究了厦门湖边水库、石兜-坂头水库水体颗粒物的分布特征及其与环境因子之间的关系。结果表明:(1)水体颗粒物平均含量以坂头库区最高,石兜库区次之,湖边水库最低,平均含量分别为31.9、27.7和23.1mg/L;在空间分布上,不同水库或库区、不同采样站位间,由于水体颗粒物的来源成因不同,其分布规律呈现出明显的差异。(2)从水体颗粒物与环境因子的关联度分析,湖边水库及石兜-坂头水库两个库区的水体颗粒物与总氮和总磷都有较大关联性。(3)利用Pearson积矩相关系数(两尾)进行检验,湖边水库及石兜-坂头水库两个库区的水体颗粒物均与总氮呈显著或极显著相关,与透明度呈显著负相关,与叶绿素a均呈负相关,与其它因子的相关规律性不明显。(4)水体颗粒物与环境因子的逐步回归分析表明,在不同的水库或库区,对水体颗粒物有显著影响的环境因子各不相同,湖边水库是高锰酸盐指数和总氮,石兜库区是高锰酸盐指数、总氮和总磷,坂头库区是pH、溶解氧和总磷。     

乌鲁木齐市可吸入颗粒物水溶性离子特征及来源解析

采暖期时在乌鲁木齐市采集了环境空气中的可吸入颗粒物,对可吸入颗粒物质量浓度及8种水溶性离子的特征和来源进行了分析。结果表明,细粒子和粗粒子的月平均质量浓度分别是53.5～233.3μg/m3和38.9～60.9μg/m3;细粒子和粗粒子中水溶性离子主要由SO24-、NH4+和NO3-组成;粗粒子中NH4+与NO3-和SO24-的相关性分别是0.70和0.66,细粒子中NH4+与NO3-和SO24-的相关性分别是0.89和0.93,铵盐是乌鲁木齐可吸入颗粒物主要存在形式;煤烟尘是乌鲁木齐市采暖期可吸入颗粒物的主要来源。     

西宁市典型开放源颗粒物粒径组成特征分析

采用BT-9300S激光粒度仪分析了西宁市道路尘、扬尘、土壤尘、建筑尘4种典型开放源的粒径组成。结果表明,4种类型尘中大粒径颗粒物占主导地位,粒径大于10 μm颗粒占到全部颗粒的73.80%以上,可吸入颗粒物的含量仅占7.06%～26.20%;建筑尘的细颗粒物含量最高,粒径小于2.5、1 μm的颗粒含量分别为8.36%±4.25%、2.42%±1.02%;道路尘的细颗粒物含量最低,粒径小于2.5、1 μm的颗粒含量分别为2.30%±0.94%、0.73%±0.28%;4种类型尘的体积平均直径、面积平均直径、中位直径分别在37.70～87.99 μm、8.50～23.53 μm、28.95～74.98 μm之间,其中道路尘的3种粒径参数最大,建筑尘最小;开放源颗粒物的粒度分布曲线主要呈头长尾短的不对称单峰分布,累积频率曲线为两段式,存在较为明显的拐点。     

Neutralization of interleukin-11 attenuates silica particles-induced pulmonary inflammation and fibrosis in vivo

Environmental exposure to crystalline silica particles can lead to silicosis, which is one of the most serious pulmonary interstitial fibrosis around the world. Unfortunately, the exact mechanism on silicosis is unclear, and the effective treatments are lacking to date. In this study, we aim to explore the molecular mechanism by which interleukin-11 (IL-11) affects silica particles-induced lung inflammation and fibrosis. We observed that IL-11 expressions in mouse lungs were significantly increased after silica exposure, and maintained at high levels across both inflammation and fibrosis phase. Immunofluorescent dual staining further revealed that the overexpression of IL-11 mainly located in mouse lung epithelial cells and fibroblasts. Using neutralizing anti-IL-11 antibody could effectively alleviate the overexpression of pro-inflammatory cytokines (i.e., interleukin-6 and tumor necrosis factor-α) and fibrotic proteins (i.e., collagen type I and matrix metalloproteinase-2) induced by silica particles. Most importantly, the expressions of IL-11 receptor subunit α (IL-11Rα), Glycoprotein 130 (GP130), and phosphorylated extracellular signal-regulated kinase (p-ERK) were significantly increased in response to silica, whereas blocking of IL-11 markedly reduced their levels. All findings suggested that the overexpression of IL-11 was involved in the pathological of silicosis, while neutralizing IL-11 antibody could effectively alleviate the silica-induced lung inflammation and fibrosis by inhibiting the IL-11Rα/GP130/ERK signaling pathway. IL-11 might be a promising therapeutic target for lung inflammation and fibrosis caused by silica particles exposure.     

薄板超塑性胀形的金属流动分析

分别在板厚均匀变薄和板厚呈线性规律变化两种假设的基础上 ,对薄板超塑性胀形过程中金属的变形规律及质点流动进行了分析 ,导出了变形前、后 ,质点点位的对应关系式 ,并与受内压薄壁球壳的均匀胀形作了比较     

日光辐射对大气真菌粒子的影响

大气中真菌粒子的衰亡和净化，除与真菌自身的因素有关外，与日光辐射也有密切关系。此文现场观测了日光辐射对大气真菌粒子的影响。结果表明，一天内大气真菌粒子浓度与日光辐射强度呈反比：大气真菌粒数直径中值与日光辐射强度呈正比：随着日光辐射强度的增大，＜３．０μｍ的大气真菌粒子，其浓度减小的速度比＞３．０μｍ的快。     

Monodisperse amino-modified nanosized zero-valent iron for selective and recyclable removal of TNT: Synthesis, characterization, and removal mechanism

Nitroaromatic explosives are major pollutants produced during wars that cause serious environmental and health problems. The removal of a typical nitroaromatic explosive, 2,4,6-trinitrotoluene (TNT), from aqueous solution, was conducted using a new recyclable magnetic nano-adsorbent ([email protected]₂NH₂). This adsorbent was prepared by grafting amino groups onto [email protected]₂ particles with a well-defined core-shell structure and demonstrated monodispersity in solution. The removal performance of the nano-adsorbent towards TNT was found to be 2.57 and 4.92 times higher than that towards two analogous explosives, 2,4-dinitrotoluene (2,4-DNT) and 2-nitrotoluene (2-NT), respectively, under neutral conditions. The difference in the removal performance among the three compounds was further compared in terms of the effects of different conditions (pH value, ionic strength, humic acid concentration, adsorbent modification degree and dosage, etc.) and the electrostatic potential distributions of the three compounds. The most significant elevation is owing to modification of amino on [email protected]₂ which made a 20.7% increase in adsorption efficiency of TNT. The experimental data were well fit by the pseudo-second-order kinetic model and the Freundlich adsorption isotherm model, indicating multilayer adsorption on a heterogeneous surface. The experimental results and theoretical considerations show that the interactions between [email protected]₂NH₂ NPs and TNT correspond to dipole-dipole and hydrophobic interactions. These interactions should be considered in the design of an adsorbent. Furthermore, the adaptability to aqueous environment and excellent regeneration capacity of [email protected]₂NH₂ NPs makes these remediation materials promising for applications.