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.     

基于CVM方法分析牧民对禁牧政策的受偿意愿——以锡林郭勒草原为例

确定居民对生态措施实施的受偿意愿,对目前迫切需要的生态补偿政策制定以及生态恢复和保护的有效性具有重要的现实意义。选用锡林郭勒草原为案例区域,通过入户调查及在那达慕大会集中调查相结合的方式,调查锡林郭勒草原地区牧民对禁牧措施的态度和受偿意愿。分析结果显示:53%的牧民愿意参加禁牧,而不愿意参加禁牧主要是由于补偿标准不合理引起的。计量经济学模型分析表明,牧民对禁牧的支持态度与牧民的收入和草地面积呈正相关,与养羊数量呈负相关。牧民的受偿意愿由牧民养羊数量、受教育年限、草地现状以及对禁牧政策的支持程度决定。根据意愿调查法初步估算锡林郭勒草原地区禁牧措施实施后牧民的补偿意愿,牧民家庭对禁牧政策的平均受偿意愿为每年每户2.7717万元,人均受偿意愿为8399元,平均每1hm2草地受偿意愿为85.95元。     

杭嘉湖蚕桑区主要大气氟污染源及治理现状

对杭嘉湖蚕桑区大气氟主要污染源——砖瓦厂氟的排放状况及各种含氟烟道废气治理装置的治理效果进行了较为深入的调查分析,认为砖瓦厂含氟废气不经烟道排放较为严重。目前砖瓦厂所采用的各种含氟废气治理装置中,旋流板塔装置除氟效率较佳,可使废气氟的排放浓度降至5mg/m~3以下,基本上能消除下风向300m以远的大气氟污染对蚕桑的严重危害。     

调节细胞通透性促进天蓝色链霉菌蓝色素生物合成

在天蓝色链霉菌分批发酵中，36h时一次加入20mg/L的青霉素，色素浓度和分泌率分别提高了26．2％和39．2％；与一次性添加青霉素相比，分多次添加可使色素浓度再提高9％，但分泌率没有明显变化。DMSO浓度为6g/L时，色素浓工和分泌率较对照分别提高了20．5％和50％；2－50g/L的DMSO对菌体生长没有影响。36h时lg/L的吐温80，色素浓度和分泌率分别提高了16．9％和37．5％，60h时加入0.2g/L浓度的SDS，色素浓度较对照基本相当，但分泌率却提高了16．1％。图4表1参7     

上海城市绿地系统构筑初探

本文从剖析上海城市绿地存在问题入手，结合城市规划配套发展原则，走生态城市大园林之路，探讨了绿地系统构筑的指导思想和原则，研究并提出了城市绿地系统的构筑的四大子系统体系。     

南岳森林群落生物多样性研究(Ⅰ)广济寺森林群落学特征

根据我们对南岳广济寺森林群落的实地考察及其调查资料统计分析结果,发现该群落是一种尚未报道的新类型,即水丝梨+甜槠-尾叶山茶+花竹-蔓赤 车群丛(Association of Sycopsis sinensis+Castnopsis eyeri-Camellia caudata+Phyllostachys nidularia-Pellionia scabra)。该群落内有维管束植物69科116属149种;其属的区系是以热带性质成分为主,温带性质成分为辅,各占56.19％和43.81％;其种的区系成分以华夏、东亚、中国-日本和华东至华中等四种类型为主,同时本群落具有明显的华东至华中过渡交迭性质。在群落中木本植物和草本植物各占71.14％和28.86％,草本植物中的多年生和一年生类型各占22.82％和6.04％。本群落可以明显划分为乔、灌、草三个层次,每个层次又可以进一步划分为三个亚层。这一群落是中亚热带东部典型常绿阔叶林北部植被地理亚带中的常绿阔叶林,在演替过程中,群落仍将保持以水丝梨为优势种的常绿阔叶林,但其亚优势种——甜槠将可能会被多脉青冈、中华石楠、长叶石栎取代。     

多效唑在鱼体内的分布,积累与类脂质含量相关性研究

实验水系统中，植物生长调节剂多效唑在鲤科类金鱼体内分布、积累的研究结果表明，＾３Ｈ－ＭＥＴ主要积累在鱼体消化系统；各器官／组织的积累量依次为：肠＞肝＞鳃＞皮＞肉＞骨；多效唑效生物积累因子（ＢＣＦ）和鱼体类脂质含量之间有较高的正相关性。     

聚醚砜超滤膜的研制

以聚醚砜为原料，二甲基乙酰胺为溶剂，研究了铸膜液组成和若干因素对膜性能的影响。选择适当的膜液组成和制备条件，可制得截留分子量分别为２０００，６０００，１００００的超滤膜，用该膜对α－干扰素进行分离。截留率均可达到９９％以上。     

Hydroquinones from defensive secretion of a giant Pacific millipede, <Emphasis Type="Italic">Acladocricus setigerus</Emphasis> (Diplopoda: Spirobolida)

Summary. The presence of considerable quantities of hydroquinones including hydroquinone, 2-methylhydroquinone, 2,3- dimethoxyhydroquinone, 2-methoxy-3-methylhydroquinone, and 2,3-dimethoxy-5-methylhydroquinone renders the defensive secretion of Acladocricus setigerus (Silvestri, 1897) significantly different from that of other quinone-producing millipedes. In addition, two hitherto undescribed compounds, namely, 2,3-dimethoxy-5-methylhydroquinone and 2-methyl-3,4-methylenedioxyphenol, were characterized from the defensive secretion. However, it is uncertain if the latter compound is formed after the release of the secretion. The two major compounds, 2-methyl-1,4-benzoquinone and 2-methoxy-3-methyl-1,4-benzoquinone, constitute about 75% of the defensive fluid. Furthermore, hydrocarbons, which are typically present in the secretions of most other arthropods that use benzoquinones as repellents, are notably absent in the secretion of A. setigerus.     

含TOA微胶囊对Cr2O7^2—萃取的研究

用乙基纤维素作膜材将三辛胺（简称ＴＯＡ）微胶囊化，用于萃取酸性水溶液中的Ｃｒ２Ｏ７＾２－离子。通过搅拌法萃取实验表明，ＴＯＡ被微胶囊化后对铬离子仍具有较高的萃取速度，实验测定渗透系数为６．７８×１０＾－６ｍ／ｍｉｎ，并能有效地防止乳化现象。将微胶囊制备成填充柱对Ｃｒ２Ｏ７＾２－进行萃取实验。对外相水的流速、微胶囊粒径、柱的重复使用次数与萃取容量的关系进行了研究。当粒径为１００－２００μｍ，流速为３