泾阳、临猗地震的地下流体异常特征

总结了１９９８ 年泾阳Ｍｓ４．８ 及临猗Ｍｓ ４．６ 级地震的地下流体异常特征, 结果表明： 异常点数量有随震中距的增大而减少的趋势, 同时又受构造条件的制约; 异常时间以短临为主, 短期异常主要集中在震前３ 个月左右, 临震异常出现在震前１０ ｄ 左右; 异常幅度与地震三要素关系不明显。     

秦岭、巴山地区山地自然灾害综合研究──以陕西柞水踩玉河流域山地自然灾害为例

本文讨论了在秦岭、巴山地区开展山地自然灾害综合研究的有关问题．并通过陕西柞水踩玉河流域的现场考察，总结研究了该流域洪水、滑坡、泥石流等山地自然灾害的主要特征，致灾原因以及防御对策等。本文对试图用科学的方法减轻山地自然灾害作了有益的探讨。     

植物络合素及其合酶在重金属抗性中的功能研究进展

Under heavy metal stress, higher plants initiate a set of defense responses, among which biosynthesis of phytochelatins (PCs) is important. PCs are rich in cystein and biosynthesized by phytochelatin synthase. The chemical structure of PCs and their ability to form complexes with a large range of metal ions is clear. Up to now, these peptides are known to play an important role in both endogenous metal ion homeostasis and heavy metal ion detoxification. The mechanism of cadmium tolerance is illustrated in detail. A model of this mechanism suggested that the detoxification process of cadmium include such steps as PCs induction, transport of cadmium into the tonoplast, formation of the HMW-Cd-PCs complexes and sequestration in vacuole. At the same time, PCs also have other functions, such as detoxification of arsenic, protecting enzyme from metal ion inhibition and supplying metal ion as a cofactor to the enzyme potentially. However, a lot of questions about its biological function remain to be answered. In 1999, three independent labs isolated the genes encoding the PCs synthase. This breakthrough of plant heavy metal tolerance research gave us a chance to further study the heavy metal tolerance mechanism. All the results from the reserch of PCs have a ffreat application potential in phytoremidation. Fig 1, Ref 25     

河北廊坊地区大气污染物变化特征与来源追踪

为了解河北省廊坊地区大气污染水平、变化特征以及污染物来源,2009年7月—2010年6月对该地区大气中NO、NO_x（NO_x=NO+NO₂）、O₃、SO₂和PM₁₀进行了连续在线观测,并用统计方法和后向轨迹模拟对所获数据进行分析。结果表明,一次污染物NO、NO_x、SO₂和PM₁₀浓度具有相似的季变化和日变化,冬季浓度最高,季节日均值分别为（57±53）、（127±84）、（69±340）和（181±129）μg/m³;二次污染物O₃夏季浓度最高,日小时均值最高值季节日平均为（99±39）μg/m³。一次污染物浓度日变化呈早晚双峰型,冬季,变化幅度最大;二次污染物日变化为单峰型,最大值出现在夏季午后。夏季受东南气流影响,往往造成该地区O₃超标;冬季,廊坊和天津污染具有较高一致性,出现区域性大气复合污染。廊坊地区大气污染除受本地排放影响,还受到周边地区污染物输送的影响,其在京津两大城市间对大气污染的缓冲作用也不可小觑。     

2001—2020年合肥市空气质量变化趋势研究

为系统分析合肥市长时间序列空气质量变化特征,对合肥市2001—2020年SO₂、NO₂和PM₁₀,以及2013—2020年CO、O₃和PM_2.5的浓度特征开展研究。采用Mann-Kendall(M-K)时间趋势检验法分析了6项污染物的时间变化规律,同时考虑了人为活动对污染物小时浓度的影响。结果表明,PM_2.5和O₃是目前影响合肥市空气质量的首要污染物。2014年以来,合肥市PM₁₀、PM_2.5、CO和SO₂年均浓度均呈逐年下降趋势,但NO₂和O₃污染有加剧趋势。合肥市SO₂和颗粒物浓度表现为冬春季节高、夏秋季节低;O₃浓度变化趋势与之相反;NO₂和CO浓度呈秋冬季节高、春夏季节低。     

北京冬季雾霾天气下颗粒物及其化学组分的粒径分布特征研究

为认识雾霾天气下颗粒物及其化学组分的粒径分布特征,利用13级低压撞击采样器采集北京城区冬季一次典型雾霾天气下的大气颗粒物,采用离子色谱和元素碳/有机碳分析仪分析了PM10中不同粒径的水溶性离子、元素碳和有机碳组分,获得了颗粒物及其化学成分的粒径分布特征.结果表明,不同天气下颗粒物质量浓度大小为:雾霾多云雪天晴天,4种天气下PM2.5/PM10均大于74%,说明冬季污染主要是由细颗粒物污染引起.SO2-4、NO-3、NH+4、Cl-、Ca2+是最主要的水溶性离子.SO2-4、NO-3、NH+4在0.76μm出现单峰;Ca2+和Mg2+在0.31和5.13~8.09μm出现双峰,主要分布在粗模态;Cl-和K+在0.76和5.13μm出现双峰,主要分布在细粒径段.OC、EC也富集于细粒子,显单峰结构.随污染程度增加,二次无机离子及碳组分浓度均显著增加,SO2、NO2的表观转化率(SOR、NOR)以及OC/EC在灰霾期间都远远高于二级良,可见二次无机源及有机源是污染的主要来源.在空气流动性差的灰霾持续期,机动车尾气排放的EC等一次污染物贡献增加.分析NO-3/SO2-4的粒径分布发现,机动车尾气对爱根核模态及凝结模态的亚微米模态(1μm)贡献大于固定源,机动车尾气排放对大气污染的贡献已十分凸显.此外,燃煤污染的区域输送对污染的形成也有重要贡献,重污染期间土壤扬尘的贡献较小.     

万州城区夏季、冬季PM_(2.5)中有机碳和元素碳的浓度特征

在位于三峡库区腹心的山地城市万州城区采集夏季和冬季PM2.5样品,采用热光反射法(Thermal Optical Reflection,TOR)测定了PM2.5中有机碳(OC)和元素碳(EC)的浓度,探讨了其污染特征及来源.结果发现,OC和EC在夏季的平均浓度分别为(7.09±1.86)μg·m-3和(3.49±0.64)μg·m-3;冬季分别为(16.82±6.87)μg·m-3和(6.21±2.06)μg·m-3,高于夏季,这可能与冬季当地居民生物质燃烧的贡献显著增加有关.冬季OC和EC显著线性相关(r=0.89),表明冬季两者的一次污染来源相近.冬季PM2.5中总碳(TC)和水溶性K+含量的相关性(r=0.88)高于夏季(r=0.69),表明冬季生物质燃烧对碳污染贡献显著.利用OC/EC比值法对二次有机碳(SOC)进行估算,SOC的浓度均值在夏季为(2.17±1.46)μg·m-3,占OC比例为28.18%±13.85%;冬季为(4.46±3.69)μg·m-3,占OC的23.13%±12.30%.通过计算PM2.5中8个碳组分丰度,初步判断机动车尾气排放和生物质燃烧是万州城区碳组分的主要来源.     

北京市远郊冬季铵盐颗粒物的单颗粒质谱研究

2016年冬季使用单颗粒气溶胶质谱仪（SPAMS）于在北京市平谷区西柏店村进行大气颗粒物的在线观测.以m/z18[NH₄]⁺为特征离子提取含铵盐颗粒物,分析其时间变化特征、粒径分布、化学组分、混合状态和可能来源.含铵盐颗粒物约占观测期间所有颗粒物的31%,分为NH₄-OC（49.9%）,NH₄-EC（5.6%）,NH₄-ECOC（8.9%）,NH₄-HOC（1.4%）,NH₄-K（9.3%）,NH₄-NaK（21.7%）和NH₄-FeK（2.5%）7种主要类别.铵盐主要以硫酸铵、硫酸氢铵和硝酸铵的形态存在,且更易于和含碳类物质发生内混.煤炭和生物质燃烧是铵盐颗粒物的主要来源.后向轨迹分析表明,清洁期气团主要来自采样点北方和西北方的长距离传输,灰霾期气团主要来自西北向的区域传输.潜在源贡献因子分析（PSCF）表明含铵盐颗粒物主要来自本地和周边区域的排放,以及西北方向的长距离传输.     

Ecotoxicological effects of mixed pollutants resulted from e-wastes recycling and bioaccumulation of polybrominated diphenyl ethers in Chinese loach （Misgurnus anguiUicaudatus）

To understand potential ecotoxicological e ects of electrical and electronic equipment waste (e-waste) recycling and polybrominated diphenyl ethers (PBDEs) bioaccumulation in loaches, a semi-field experiment using Chinese loach (Misgurnus anguillicaudatus) as experimental fish was performed. Larval loaches were kept in net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant di erence of the survival rate between the loaches from the e-wastes recycling site (27%, 19/70) and from reference site (70%, 49/70). Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological e ects on loaches. The bioaccumulation of polybrominated diphenyl ethers (PBDEs), the main pollutants in e-waste, in loaches was also studied, the mean concentration of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L (dissolved phase). BDE 209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE 209 (less than 0.01% of total PBDEs) and high concentration of BDE47 (up to 39.34% of total PBDEs) were detected in loaches.     

Study on the migration mechanisms of water-soluble agents in high-pressure rotary jetting remediation

Environmental Science and Pollution Research - High-pressure rotary jetting (HPRJ) remediation is a recent-applied technology for in situ remediation of contaminated soils. The effectiveness of...