北京东南郊污灌区土壤有机氯农药的垂向分布特征

采用GC-ECD分析了北京东南郊污灌区土壤剖面中有机氯农药(OCPs)的垂向分布特征及其地下水样.结果表明,表土是OCPs的主要累积层位,OCPs总量残留量的最大值为30.93μg·kg-1,其中的主要污染物为DDTs和HCHs.但与国内外其他地区检出浓度相比,DDTs属于轻度污染,HCHs属于中度污染.表层以下,OCPs含量整体随采样深度加深而明显下降,土壤剖面中的主要污染物为4,4′-DDE、七氯和艾氏剂,但是检出浓度均不高.多元回归分析表明,土壤的TOC含量和含水量是影响OCPs垂向分布的主要因素.地下水样中除DDTs无检出外,其余检出物与土壤剖面中一致,说明在长期污灌条件下,可能会导致浅层地下水的污染.     

Spider orientation and hub position in orb webs

Orb-web building spiders (Araneae: Araneoidea, Uloboridae) can be considered as territorial central place foragers. In territorial central place foragers, the optimal foraging arena is circular, with the forager sitting in its centre. In orb webs, the spider’s orientation (head up or head down) whilst waiting for prey on the hub of its web and the downwards–upwards asymmetry of its running speeds are the probable causes for the observed deviation of the hub from the web’s centre. Here, we present an analytical model and a more refined simulation model to analyse the relationships amongst the spider’s running speeds, its orientation whilst waiting for prey and the vertical asymmetry of orb webs. The results of our models suggest that (a) waiting for prey head down is generally favourable because it allows the spider to reach the prey in its web on average quicker than spiders waiting head up, (b) the downwards–upwards running speed asymmetry, together with the head-down orientation of most spiders, are likely causes for the observed vertical asymmetry of orb webs, (c) waiting head up can be advantageous for spiders whose downwards–upwards running speed asymmetry is small and who experience high prey tumbling rates and (d) spiders waiting head up should place their hub lower than similar spiders waiting head down.     

大庆市杜蒙地区部分蜘蛛种类的调查

本文将大庆市杜蒙地区的屋舍、草甸、杨树林3个区域进行蜘蛛种类调查研究。共记述蜘蛛目9科,21属,22种,并对3个区域的分布特点进行了分析。据此,从环境保护角度提出了合理化建议。     

镉胁迫下大豆中镉的分布状况及其籽粒品质

溶液培养中0.5μmol·L-1镉胁迫浓度下,大豆表现出轻微受害症状,籽粒减产25 . 7%,而籽粒中粗脂肪和粗蛋白含量变化不大.镉在大豆中的积累分布状况为根>叶>籽>油,比例为32.100:1.690:1.000:0.003.大豆籽粒含镉4.89mg/kg,超过了国家环境标准规定的最高容许量.而大豆粗脂肪中含镉仅0.015mg/kg,远低于国家食品环境卫生标准.豆粕中含镉6.17mg/kg,表明大豆籽粒中的镉主要存在于粗蛋白和淀粉中.     

Evaluating rainwater contamination and sources in southeast Australia using factor analysis

Factor analysis is used to evaluate inorganic ion relationships to provide a qualitative determination of continental sources of rainwater contamination in the Hunter Region, New South Wales, Australia. The rain water was collected between October 1984 and March 1986 at 32 sites and forms the database for the Hunter Region Acid Rain Project. The results show that soil and animal/fertilizer sources determine rainwater quality over most of the Hunter Region, and dominate as the major sources when the entire data set is analysed as a whole. When individual sites are analysed, the industrial emissions factor is important at six adjacent locations in the Middle Hunter, suggesting some transport of sulphate and nitrate from industrial sources 50 to 80 km to the east and southeast may be occurring. Factor analysis by rainfall event provides similar results to site analysis, with only 4 events out of 34 dominated by the industrial emissions factor. The results indicate that rainwater quality is influenced by local and regional sources, and not by long-range transport from Sydney, 175 km to the south. Comparison of the Hunter Region ion relationships to those from a more heavily acidic area, the northeast U.S.A. (MAP3S/RAINE Network), demonstrate some similarities in associations but the correlations associated with the hydrogen ion are better defined in the U.S. data set.     

Optimal Area Use in Orb Webs of the Spider Araneus diadematus

 We studied the abilities of the garden cross spider Araneus diadematus regarding adaptation of web geometry to spatial constraints. Spiders reacted to a spatial reduction in their building site from a square-shaped frame to a slimmer, rectangular frame (side ratio 1 : 2) by maintaining overall web geometry while reducing the web area covered by the sticky capture spiral. However, when the frames were changed further to a rectangular side ratio of 1 : 3, the spiders changed specific web properties in such a way that a further reduction in the capture spiral area was prevented. Construction of the threads making up the web frame and the auxiliary spiral requires that the spider explores the spatial constraints of its building site. The geometry of both frame and auxiliary spiral threads in turn determine the geometry of the capture threads. Since in very narrow frames the spider adjusted the auxiliary to suit the subsequent capture spiral, we suggest that an initial spatial survey led to the final adaptation of overall web geometry to a web site. Received: 26 April 1999 / Accepted in revised form: 26 November 1999     

华东地区矿产资源调查新成果及工作建议

介绍了近年来华东地区资源调查评价的新成果。表明本地区仍具有较大的找矿潜力。并提出了华东地区下一阶段矿产资源调查工作的建议。建议分区域矿产调查、预查、普查三个工作层次。重点在武夷山铜铅锌成矿带、赣南钨多金属成矿区和皖赣相邻地区铜多金属成矿区(一带两区)。侧重铜、锡、钨、富铅锌等。     

东南沿海地区钢质包装弹药的储存管理研究

为了进一步做好钢质包装弹药的保障工作,在分析东南沿海地区的气候环境的基础上, 着重从包装储存功能角度研究钢质包装材料的功能特点,并讨论了采用钢质包装对弹药储存工作带来的不利影响,最后提出了在东南沿海地区恶劣气候条件下钢质包装弹药的储存与管理措施。     

Status and circulation characteristics of soil water in dryland field of southeast Shanxi Province

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土壤添加亚砷酸钠对大豆生长和植株氮、磷、钾含量的影响

利用土壤盆栽实验,研究了0、5、10、30、50、100mg·kg^-1的土壤加砷水平对大豆生长和氮、磷、钾养分含量的影响.结果表明,当土壤加砷水平达到50mg·kg^-1时,大豆出现中毒症状,叶片皱缩,叶色变暗,叶缘焦枯,植株矮化,成熟延迟.大豆株高随加砷水平的提高而降低,并呈极显著的负指数相关关系.土壤加砷达到10...     

南方典型旅游城市空气微生物粒径分布特征

在南方典型旅游城市杭州选取了4个样点进行了空气微生物取样工作.系统研究了杭州市室外空气微生物粒径分布特征.结果表明,不同样点空气细菌粒子百分比从Ⅰ级到Ⅵ级逐渐减少,总体呈偏态分布.交通干线,文教区,商业区和旅游风景区细菌粒子百分比最高值均出现在Ⅰ级,分别占29.1%,31.8%,33.5%和25.4%,最低值均出现在Ⅵ级,分别占11.7%,11.2%,6.5%和11.1%.不同样点空气真菌主要分布在Ⅲ级、Ⅳ级和Ⅴ级,总体呈对数正态分布,真菌百分比最高值均出现在Ⅳ级,分别占30.3%,30.2%,31.7%和28.3%,最低值出现在Ⅵ级,分别占5.2%,5.1%,3.3%和4.5%.青霉属,链格孢属,曲霉属和枝孢属优势真菌粒径均呈对数正态分布特征,但取样器各级真菌百分比各不相同.此外,空气细菌中值直径显著大于空气真菌,商业区空气细菌中值直径显著大于其他3个样点,而文教区真菌中值直径显著大于其他3个样点.研究结果进一步说明了城市室内外空气微生物粒径分布特征的不同,为室内外空气微生物污染的预防和控制提供了科学依据.     

AGNPS在我国东南亚热带地区的检验

利用地理信息系统（GIS），基于数字高程模型（DEM），提取AGNPS（A Agricultural Non-Point Source Model)模型所需的水文和地形参数，并通过实地调查及专题制图等手段获取AGNPS模型所需的土地利用、土壤质地及施肥水平等其它参数，最后利用监测降水，实测水文参数、营养盐及沉积物负荷等验证AGNPS模型在我国东南亚热带地区的应用。     

论浙东南磨石山群祝村组的解体

对浙东南磨石山群祝村组层型———丽水祝村剖面及其附近进一步地质调查时发现祝村组“下伏”的九里坪组为一个英安玢岩侵出体。祝村组建组的基础不存在。祝村组下部英安质熔结凝灰岩和上部流纹岩Nd同位素测定结果 :εNd(t)值和T2DM值分别为 - 9.6、- 7.2和1.70Ga、1.5 1Ga ,表明它们物质来源不同 ,属于不同火山旋回的产物。根据地层层序、岩石组合及与区域磨石山群地层对比 ,祝村组应解体为西山头组、茶湾组和九里坪组。祝村组一名不宜继续使用     

闽东南特色农业生态模式研究

基于闽东南的资源优势,把发展亚热带水果作为特色农业。由于生态环境脆弱,必须寻求特色农业生产的最佳模式。本研究设计果农草牧复合系统作为特色农业的生态模式。试验表明:生态模式与传统模式相比,泥沙流失量仅是传统模式的26.3%和48.4%,0～20cm土层的有机质含量增加3.8g/kg和5.5g/kg。土地单位面积能量总产出是传统模式的5.1倍。本生态模式显示生产良好循环,取得有效的生态和经济效益,并有很好的发展前景。     

Erosion risk associated with rapid and extensive agricultural clearances on dispersive materials in southeast Spain

This research explores the socio-economic, climatic and lithological components of the contemporary erosion problems in the Sorbas area of Almeria, Spain, and devises a mapping schedule to describe the particular risks associated with the large-scale clearance of dispersive soils for arboriculture. The paper firstly tracks the pace of the agricultural change across this sensitive landscape using provincial agricultural statistics. Secondly, the elements of geomorphological sensitivity in a 70 km² study area southwest of Sorbas are considered. Previous work has suggested that dispersive properties of local lithologies are important risk-associated variables alongside vegetation cover and topography. A method whereby all these factors can be included in the assessment of the degree of erosion risk is developed. Using repeat NERC air photography for 1996 and 2001 as a basis, aerial photomosaics of the study area are compared, producing a map of land-use change between 1996 and 2001. With this map as a basis, the risk-mapping schedule is piloted for a sub-study area on newly cleared land. The sustainable management of these extensive changes is discussed in a final section. It is argued that the proposed algorithm for erosion risk mapping could facilitate the management of existing agricultural clearances, and the siting of new developments to minimise soil loss.     

湖南采矿区和冶炼区水稻土重金属污染及其潜在风险评价

对湖南省9个县市采矿区和冶炼区附近的水稻土中重金属Cd、As、Cu、Zn和Pb进行了调查和分析.结果表明,采矿区和冶炼区周围的水稻土中重金属Cd、As、Cu、Zn和Pb的含量呈对数正态分布.单因子污染指数法评价表明,在所调查的区域中,有6个县市矿区和冶炼区附近的水稻土受到Cd的严重污染,其它地区的水稻土分别受到Cd、As、Cu、Zn和Pb不同程度的污染,其中衡阳常宁市水口山铅锌矿区和株洲清水塘冶炼区附近的水稻土受到重金属的严重污染.潜在风险评价表明,采矿区和冶炼区周围的水稻土中Cd潜在风险参数最高,其次是Pb和As.衡阳常宁水口山铅锌矿、株洲清水塘冶炼区、娄底冷水江锡矿和湘潭锰矿附近的水稻土中重金属的潜在生态风险参数很高,具有很高潜在风险程度;永州道县冶炼区水稻土中重金属的潜在生态风险程度为较高程度;郴州柿竹园铅锌矿.常德石门雄磺矿、益阳赫山区金矿区和岳阳临湘铅锌矿区附近的水稻土的重金属潜在生态风险为中等程度.