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991.
The associated industrial and urban developments are located to a large extent along the Laizhou Bay, Bohai Sea coastal and
raw sewage is often discharged into near shore waters with little treatment. To find out chemical characteristics and pollution
source of the petroleum related contaminations in sediments near the major drainage outfalls located in the coastal, in this
study, 10 surface sediment samples were collected during June. Sediment samples were extracted by organic solvents, separated
by silica gel column chromatography and the concentrations and the profiles of n-alkane, biomarker and PAH in sediments were analyzed by gas chromatography-mass selective detector (GC-MSD). The use of several
molecular markers and related indexes derived for n-alkane and PAHs has been proposed for assessing the relative contributions to the environment of hydrocarbon sources. As
a result, n-alkanes reflect that the sea area of paper mill (Station ZZ08) is dominated by vascular plant. DY petroleum oil field and
outer shore of the paper mill (Station ZZ02) have some degrees of petroleum related hydrocarbon contamination. Whereas the
contamination of the sea area of TH River may be ascribed to different sources such as territorial non-point pollution source,
domestic sewages, and stormwater runoff. Judged by their PAH ratios, the sediments near the paper mill (Station ZZ02) and
the outer station of the oil field (Staion TH2) were pyrolytic. The estuary of Tiao River including the inner Station THX,
TH10 and TH05 are petrogenic. The marine sediment near DY drainage outfall may have a mixture source of PAH both pyrolytic
and petrogenic. 相似文献
992.
自然灾害风险评估国际计划述评Ⅱ——评估方法 总被引:7,自引:6,他引:1
自然灾害风险评估是综合灾害风险管理的关键途径,而评估方法又是灾害风险评估的关键.总结了近年来3个重要的自然灾害风险评估国际计划:灾害风险指标计划(DRI)、多发展指标计划(Hotspots)和美洲计划的(American Programme)分析单元、灾种选择和数据源.评述了3个国际计划采用的数据处理方法、模型和评估方法:计算DRI的指标需计算3个数值--物质暴露、相对脆弱性和社会-经济脆弱性指标;Hotspots首次利用栅格单元和地区/财富等级来计算死亡风险和经济损失风险;美洲计划分别建立了4个独立指标的计算模型,并应用到城市级别.通过比较3个国际计划的风险评估方法的优点与不足,提出了今后灾害风险评估的重点和关键应是风险的时空分布、动态风险评估和案例研究. 相似文献
993.
994.
嘉陵江上游暴雨洪水特性分析 总被引:1,自引:0,他引:1
介绍了流域气候和地理特征,分析了流域降水、径流特性和泥沙特点;通过对历年暴雨洪水资料的统计,分析了流域内暴雨洪水形成的规律;对干流段灾害性洪水的重现期及大洪水发生的周期和季节规律进行了分析,并提出了防洪减灾对策. 相似文献
995.
996.
基础施工是基础设施建设中的首要环节,是整个工程建设赖以进行的基础工作,因而国家颁布了一系列标准与规程,用以确保施工质量与安全。本文就基础工程施工中事故隐患的整改谈谈个人看法。 相似文献
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999.
With the threat of wildfire hanging over many communities in the Western and Southern United States, wildfire mitigation is evolving into a significant public responsibility for rural and urban edge county governments. Regional governance is an important piece of the effort to reduce wildfire risks although still weakly developed as a policy arena. This project explores two dimensions in which planning support systems can support regional governance: assessing patterns of wildfire risk accumulation; and, evaluating land use planning alternatives and their effects on cumulative risk levels. These tools are examined for regional governance using a prototype planning information system, the Alternative Growth Futures (AGF) tool, a scenario-building approach developed at the University of Colorado Denver. The project develops a hybrid urban growth model that integrates logistic regression techniques and methods for simulation of growth alternatives. This model is used to evaluate the attractiveness of undeveloped building sites with respect to natural amenities, distance to primary urban services and site characteristics such as slope. The model and scenario-testing framework are reasonably robust and suggest that regional spatial accounting methods have potential as a framework for inter-governmental and public discussion around wildfire planning. 相似文献
1000.
为了利用廉价材料规模化生产微生物絮凝剂,以味精废水作为廉价培养基质,对酱油曲霉的摇瓶连续培养和发酵罐连续培养进行了研究。摇瓶中以5%的接种量进行连续培养,最适温度在30~33℃之间,每6h替换一次新鲜废水培养基,5次替换新鲜废水培养基后最大絮凝率仍达到97.8%。在发酵罐扩大连续培养中以5%的接种量接种后经过9h预培养达到稳定生产絮凝剂后,以4mL/min的补料流量进行连续培养,生产的絮凝剂产量达到2.392g/L,且最大絮凝率为98.1%。生产36h后对发酵系统中菌体进行稀释,使菌体量保持在50—200g/L之间可持续进行生产。 相似文献