Fluorosis caused by indoor coal combustion in China: discovery and progress

In this study, investigations into endemic fluorosis were conducted and fluorine concentration in environmental samples determined. In an indoor coal-combustion-type fluorosis area, local clay was used to mix with coal for indoor combustion. There are two key steps in the procedure of the indoor transition of fluorine: indoor wet corns and vegetables strongly absorbed fluorine from indoor air; and fluorine strongly accumulated in clay, which was mixed with coal for combustion. Therefore, with the increasing of the percentage of clay in the clay-mixed coal as well as corn in foodstuff, the ratio of fluorosis will be increased.     

活性炭吸附水中铅离子的动态研究

本文采用两种煤质活性炭，研究了其对不同浓度二价铅离子溶液的吸附，应用固定床吸附动力学模型，Ｍａｒｑａｄｔ方法非线性回归固定床吸附流出曲线，获得了铅离子在活性炭上的扩散传质系数。结果发现，孔扩散系数Ｄｐ强裂地依赖于铅离子入口浓度，随着入口浓度的升高，孔扩散系数变小，随后用上述扩攻系数理论预测了其它操作条件下的流出曲线，结果表明实验曲线与理论预测曲线能很好地相符，动态法能可靠地获取固吸附过程的吸附及扩     

拓扑指数在定量结构生物降解性关系中的应用

本文采用二氧化碳生成量实验，对训练组有机物，利用逐步回归分析程序，从计算和十四种分子连接性指数中筛选出与生物降解性最为相关的分子结构描述参数，建立定量结构－生物降解性关系模型，其相关系数为０．９３１，利用该模型对预测组质的预测结果表明，此模型对芳香化合物的好氧生物降解性具有良好的预测能力，其正确预测率达８３．３％。     

西太平洋海域海水和雨水的化学特征

本工作测定了西太平洋海域中海水、海水悬浮物和海面上雨水的元素组成和浓度。通过富集因子的计算,探讨海面上雨水中微量元素的富集程度及其来源,讨论了海面上气溶胶粒子大小与洗出因子的关系,结果表明不同质量粒径大小的微量元素在公海上具有相似的洗出因子。     

系统聚类分析在农户生态系统类型划分中的应用

应用主成分分析法和系统聚类分析法，对湖北省京山县刘家岭村５０个农户进行了生态系统类型数值分类分析，结果表明，该村农户生态系统可分为农－牧业型、果－农－牧业型和渔－农－牧业型三类，与全村３３８个农户情况相符。     

Loss of pesticides from agricultural fields in SE Norway--runoff through surface and drainage water

Loss of two pesticides with different mobility characteristics, bentazone (Koc approximately 34) and propiconazole (Koc approximately 1800), were studied at three agricultural fields (Askim, Bj?rnebekk and Syverud) in SE Norway. A conservative tracer (Br) was used to follow the flow of water. The loss of pesticides varied among the fields, depending on hydrological characteristics and soil properties. The loss of pesticides was higher from two artificially levelled silty clay loam soils with poor aggregate stability (Askim and Bj?rnebekk) compared to a loam/silt loam soil with increased content of organic carbon and better aggregate stability (Syverud). The total accumulated loss was <0.5% from all fields. The highest pesticide concentrations were measured at the first runoff episode after application for both the mobile (bentazone) and less mobile pesticide (propiconazole) in the surface runoff. In the drainage water, the peak for the less mobile pesticide coincided with the Br tracer, while the peak for mobile pesticide appeared earlier than the Br tracer. Rapid movement of water, particles and pesticides through soils indicate flow through macropores. Larger proportions (in percent of total applied) of both the mobile and the strongly sorbed pesticides were lost through the drainage as compared to the loss through surface runoff at Askim. Here, it is suggested that macropore flow contribute to the increased loss of pesticides through the drainage. At Syverud, high infiltration capacity reduces the amount of water available for surface runoff, and somewhat higher loss of the mobile pesticide was registered in the drainage compared to the surface runoff. For the strongly sorbed pesticide, however, propiconazole was neither detected in surface nor in drainage water at Syverud. Generally, there was a higher percentage loss of the mobile compared to the strongly sorbed pesticide in both surface and drainage water, which is in agreement with the pesticides mobility characteristics in soil. An exception was, however, the erodible soil Bj?rnebekk, where a higher fraction of propiconazole was lost in the surface runoff compared to bentazone. Large amounts of sediment transport from the Bj?rnebekk field probably contributed to enhanced transport of the strongly sorbed pesticide.     

有机物料与~(32)P标记过磷酸钙混合施用对磷有效性的影响

本试验利用~(32)P示踪法研究赤红壤上两种有机物料与过磷酸钙混合施用对磷有效性的影响。盆栽试验表明,纸厂废料蔗渣或猪粪与磷肥混合施用比磷肥单独施用更有利于提高格拉姆柱花草的含磷量和总吸磷量。单位施磷量引起的土壤有效磷和植株吸磷量的增加量也是有机物料单施或与磷肥混施高于磷肥单施。在前39d,~(32)P标记过磷酸钙的利用率在单独施用时为2.14％,比混合施用高一倍左右;在80d时,混合施用的磷利用率较快提高,蔗渣与磷肥混施处理超过单独施用,达22.88％。     

吸烟烟气引起鼠肝微粒体脂质过氧化的ESR波谱研究

本文用ESR自旋捕集技术,以4-POBN为捕集剂,研究了吸烟烟气处理的鼠肝微粒体体系中的自由基性质。结果发现,在吸烟烟气处理的鼠肝微粒体中,4-POBN捕集到了自由基信号,这一信号的强度随温育时间的延长及充入烟气的量增加而增强,根据其性质及ESR波谱参数分析,体系中产生了脂类自由基。结果说明,吸烟烟气刺激了鼠肝微粒体的脂质过氧化。     

赤壁市生态旅游资源特色与开发

赤壁生态旅游资源丰富,特色鲜明,类型齐全,具有较大的开发价值。通过对赤壁市开发条件、开发力和客源市场的分析,作者指出了该市开发旅游资源的巨大前景,提出了建立七种不同类型生态旅游区的构想。