热带海洋环境中BHC和DDT的行为特征研究 Ⅱ.中国珠江口区雨季BHC和DDT的含量与分布

本文于１９９５年７月在东经１１３°００′００″～１１３°５８′００″，北纬２２０°００′００″～２２°４４′００″的珠江口区采集海水、表层沉积物、气溶胶和海洋生物。用气相色谱法测定研究样品中ＢＨＣ和ＤＤＴ的含量与不同区域的分布。结果表明，就其平均值而言，表层海水ＢＨＣ含量为０．０４５μｇ／ｄｍ３，ＤＤＴ为０．０４１μｇ／ｄｍ３；底层海水ＢＨＣ含量为０．０４８μｇ／ｄｍ３，ＤＤＴ为０．０３５μｇ／ｄｍ３。沉积物ＢＨＣ为１１．０７×１０－９·干；ＤＤＴ为１７．８８×１０－９·干。气溶胶ＢＨＣ为０．１３６ｎｇ／ｍ３；ＤＤＴ为０．０７８ｎｇ／ｍ３。海洋生物ＢＨＣ的范围为０．４０３×１０－９·鲜（海带）～８．６４４×１０－９·鲜（贻贝）；ＤＤＴ为１．７７０×１０－９·鲜（浮游植物）～２０７．６×１０－９·鲜（海鸟）。在雨季，海水中ＢＨＣ和ＤＤＴ由于受到珠江径流的稀释而含量偏低；ＢＨＣ、ＤＤＴ在表层海水及表层沉积物的区域分布，雨季和旱季类似。ＢＨＣ和ＤＤＴ在海洋生物中的含量，随着海洋食物链成员生物营养级的提高而提高。它们在不可食部分的含量高于可食部分，海鸟的羽毛是积累ＢＨＣ和ＤＤＴ的关键器官。     

Biological exposure models for oil spill impact analysis

1　ＢｒｉｅｆｄｅｓｃｒｉｐｔｉｏｎｏｆｏｉｌｓｐｉｌｌｉｍｐａｃｔａｎａｌｙｓｉｓｓｙｓｔｅｍＡｓｌｏｎｇａｓｃｒｕｄｅｏｉｌｓａｒｅ ｐｒｏｄｕｃｅｄｏｆｆｓｈｏｒｅａｎｄｔｒａｎｓｐｏｒｔｅｄａｃｒｏｓｓｔｈｅｓｅａｓｂｙｓｈｉｐｓｏｒｐｉｐｅｌｉｎｅｓ,ｔｈｅｒｅｉｓａｒｉｓｋｏｆｏｉｌｓｐｉｌｌｓｗｉｔｈｔｈｅｐｏｔｅｎｔｉａｌｔｏｃａｕｓｅｓｉｇｎｉｆｉｃａｎｔｅｎｖｉｒｏｎｍｅｎｔａｌｄａｍａｇｅ .Ｔｈｅ“ＥｘｘｏｎＶａｌｄｅｚ”ｉｎｃｉｄｅｎｔｉｎＡｌａｓｋａ ,ａｎｄｏｔｈｅｒｏｉ…     

地壳内部流体与金成矿关系的研究现状与进展

大量的证据显示 ,在金的成矿作用过程中 ,地壳内部流体扮演着十分重要的角色。流体不仅可以通过与含金原岩的相互作用实现对金的萃取 ,同时还参与成矿物质运移以及金的最终沉淀并富集成矿这一整个成矿作用过程。因此 ,加强对流体与成矿的相互关系研究已成为研究金成矿学的重要内容。     

~(60)Co、~(85)Sr和~(134)Cs在非饱和黄土中迁移特征研究

经过2年的野外核素示踪试验、实验室柱试验、批实验以及数值模拟，获得^60Co、^85Sr和^134Cs在非饱和黄土中迁移特征如下：（1）非饱和黄土上述核素具有很强的吸附作用，经2年的试验，^85Sr的浓度峰位在天然条件下迁移不到2cm，喷淋条件下迁移13cm；^60Co和^134Cs在天然和喷淋条件下迁移甚微。（2）^85Sr在喷淋条件下迁移出现两个浓度峰。（3）^60Co、^85Sr和^134Cs迁移“快成份”在环境的安全评价中不容忽视。（4）在含水量和入渗水量很低时，扩散对核素迁移起主导作用。(5)水入渗量对^85Sr迁移速度和横向扩散无明显影响。（6）静态法测定的Kd值比野外求得的值大。（7）核素在非饱和黄土中的延迟系数Rd不是常数。     

Numerical model of compressible gas flow in soil pollution control

ＩｎｔｒｏｄｕｃｔｉｏｎＬａｎｄｆｉｌｌｇａｓｗｉｌｌｂｅｇｅｎｅｒａｔｅｄａｆｔｅｒｏｎｅｙｅａｒｏｆｌａｎｄｆｉｌｌｉｎｇｏｆｍｕｎｉｃｉｐａｌｓｏｌｉｄｗａｓｔｅ .ＴｈｅｃｏｍｐｏｎｅｎｔｓｏｆｌａｎｄｆｉｌｌｇａｓａｒｅｍａｉｎｌｙＣＨ4 ,ＣＯ2 ,ｗｉｔｈａｄｄｉｔｉｏｎａｌｓｏｍｅｔｒａｃｅｃｏｎｓｔｉｔｕｔｅｓｓｕｃｈａｓＮ2 ,Ｈ2 ,Ｈ2 Ｓ ,ａｎｄｖｏｌａｔｉｌｅｏｒｇａｎｉｃｃｏｍｐｏｕｎｄａｎｄｓｏｏｎ .Ｌａｎｄｆｉｌｌｇａｓｗｉｌｌｂｅａｃｃｕｍｕｌａｔｅｄｉｎｔｈｅｌａｎｄｆｉｌ…     

Release of uranium from rock matrix—a record of glacial meltwater intrusions?

Uranium release observed in a rock matrix around water-carrying fractures was studied using U-series disequilibrium (USD) modelling and mass balance calculations. Several release scenarios were tested, with specific attention to the glacial aspects. The release appears to have occurred in two or three violent episodes during the last 300 ky. A release after the last glaciation can be excluded on mass flow grounds. Continuous release for more than 300 ky can be excluded on radioactive disequilibrium grounds. Repeated inflows of oxic glacial meltwater seem to have triggered the release episodes.     

Cardenolide content,emetic potency,and thin-layer chromatography profiles of monarch butterflies,Danaus plexippus,and their larval host-plant milkweed,Asclepias humistrata,in Florida

Summary This paper is the fourth in a series on cardenolide fingerprints of monarch butterflies (Danaus plexippus, Danainae) and their host-plant milkweeds (Asclepiadaceae) in the eastern United States. Cardenolide concentrations ofAsclepias humistrata plants from north central Florida ranged from 71 to 710 µg/0.1 g dry weight, with a mean of 417 µg/0.1 g. Monarchs reared individually on these plants contained cardenolide concentrations ranging from 243 to 575 µg/0.1 g dry weight, with a mean of 385 µg/0.1 g. Cardenolide uptake by butterflies was independent of plant concentration, suggesting that sequestration saturation occurs in monarchs fed cardenolide-rich host plants. Thinlayer chromatography resolved 19 cardenolides in the plants and 15 in the butterflies. In addition to humistratin,A. humistrata plants contained several relatively non-polar cardenolides of the calotropagenin series which are metabolized to more polar derivatives in the butterflies. These produced a butterfly cardenolide fingerprint clearly distinct from those previously established for monarchs reared on otherAsclepias species. In emetic assays with the blue jay,Cyanocitta cristata, the 50% emetic dose (ED₅₀) per jay was 57.1 µg, and the average number of ED₅₀ units per butterfly was 13.8, establishing that this important south eastern milkweed produces highly emetic, chemically defended monarchs. Our data provide further support for the use of cardenolide fingerprints of wild-caught monarchs to make ecological predictions concerning defence against natural enemies, seasonal movement and larval host-plant utilization by monarch butterflies during their annual cycle of migration, breeding and overwintering.     

边界元法在填埋场气体运移数值模拟中的应用

基于多孔介质流体动力学理论和边界元法原理,构建了填埋气运移边界元数值模型,进行填埋场内部填理气的运动规律研究;通过与理想条件下的解析解对比分析,检验了该边界元数值模型方法本身;进行了垂直抽气井设施的填埋场实例气体运动数值模拟,得到了填埋场内部填埋气体的压力分布情况,由此确定了集气井的影响范围.模型精度分析和模型验证结果表明,该模型与解析解的平均相对误差在3%以下,与实测数据的平均相对误差均在10%左右,具有较高的精度;抽气井模拟结果表明,该模型可应用于填埋场气体运移的模拟预测和现场分析,能够为填埋场释放气体控制系统设计和优化提供理论依据.     

沈阳北部污水处理厂出水回用于丁香湖溶质运移预测

通过对北部污水处理厂出水、丁香湖地区水环境质量现状评价,采用Visual MODFLOW数值模拟方法预测北部污水处理厂出水再生回用于丁香湖后研究区水质的变化情况,分析由此可能带来的水环境水质风险,来研究北部污水处理厂出水再生利用于丁香湖方案在水质上的可行性。预测结果显示：在地下水动力场作用下,随着时间的延长,SO4^2-将向下游不断运移并出现了累积现象,污水再生利用到丁香湖后,对地下水环境未来情况有一定的影响。     

复合垂直流人工湿地对有机磷阻燃剂的净化

为探索有效处理有机磷阻燃剂（OPFRs）废水的方法,本文构建了复合垂直流人工湿地（IVCWs）,探究不同进水C/N比与是否曝气等运行工况下系统对磷酸三（1-氯-2-丙基）酯（TCPP）的去除效率影响,并观察目标物在湿地系统各介质中的迁移行为及相关机理.结果表明,不同工况下IVCWs对TCPP去除效果存在显著差异.与进水C/N=3时系统对TCPP去除率（52.28%±11.64%）相比,增加进水C/N、曝气和两者联用可使去除率分别提高至（68.77%±2.49%）,（57.21%±1.76%）和（89.64%±1.94%）.通过分析系统中各相累积量发现,植物（0.09%）和基质（3.30%）中TCPP的累积有限.火山岩（162.39~435.01ng/g dw）和沸石（131.67~407.74ng/g dw）中TCPP含量显著高于土壤（32.63~149.94ng/g dw）.植物体内,与菖蒲（432.95ng/g dw）、香蒲（665.21ng/g dw）相比,风车草（1288.82ng/g dw）更易TCPP累积.不同植物中TCPP主要富集在根部,有向叶片转移的趋势.探究IVCWs对TCPP的去除潜能及迁移行为,对系统缓解OPFRs污染具有积极意义.