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401.
赤峰市科尔沁沙地重要生态功能保护区生态环境现状评价及可持续发展战略探讨 总被引:1,自引:0,他引:1
本文对科尔沁沙地生态环境特点、现状、生态环境恶化的主要原因及对经济、社会和环境产生的影响进行了评价,并提出了科尔沁沙地经济、社会可持续发展的对策及发展战略,为全面落实《全国生态保护纲要》提供依据。 相似文献
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观音阁水库水体中氮、磷污染现状及其防治对策 总被引:1,自引:0,他引:1
孟凡青 《辽宁城乡环境科技》2006,26(4):13-15
本文通过对观音阁水库的水质进行监测和调查分析,了解观音阁水库水体中氮、磷污染状况及来源。根据监测和调查结果可以判断,磷是观音阁水库中限制性营养盐。通过采取必要的防治对策和措施,控制氮、磷的浓度,不仅可以控制观音阁水库水体富营养化程度,而且还能产生一定的经济效益。 相似文献
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Dermatas D Dadachov M Mirabito M Meng X 《Journal of the Air & Waste Management Association (1995)》2003,53(11):1363-1372
Artificially contaminated (spiked) natural soils were solidified/stabilized using various combinations of commonly used additives, such as lime, cement, fly ash, activated carbon, and silica fume. The effectiveness of the solidification/stabilization (S/S) processes was evaluated based on experimental findings from compaction testing, unconfined compressive shear strength, and X-ray diffraction (XRD). Correlations of limited reliability between unconfined compressive strength and penetrometer and torvane measurements were derived. Results from XRD experiments indicated that certain organic contaminants (i.e., naphthalene and pyrene) might impact the S/S processes for a given combination of additives. The type and amount of organic contaminants also affected the pozzolanic reactions. Specifically, the absence or small peak intensity of pozzolanic product XRD patterns for a given combination of additives was a good indication that the type and the amount of organic contaminant present inhibited pozzolanic reactions. This phenomenon was tested and confirmed for actual field-contaminated samples. 相似文献
406.
To demonstrate conformity of transportation projects to National Ambient Air Quality Standards in accordance with State Implementation Plans, the U.S. Environmental Protection Agency (EPA) uses intersection level of service (LOS) as one of its major criteria for screening for potential carbon monoxide (CO) hotspots. Although intersection LOS is a measure of traffic volume, signal timing, and related congestion and delay, the assigned level reflects only the computed averaged stopped delay (ASD) per vehicle at the intersection. Thus, intersections can often operate at the same LOS but produce vastly different levels of predicted CO concentrations. For example, a two-lane approach operating at LOS D will produce very different levels of CO than a five-lane approach also operating at LOS D. This study explores the effectiveness of the LOS D criterion as a screen for identifying potential CO hotspots. The study results indicate that LOS is a poor predictor of potential CO hotspots when compared to results generated with the EPA-recommended micro-scale model CAL3QHCr. To more consistently screen out those intersections that will not be identified as CO hotspots using the micro-scale models, a new criterion, equivalent red-time vehicles (ERTV), is introduced. The modeling results using ERTV suggest that it is a more robust measure for identifying potential CO hotspots, and conversely, screening out those intersections that are not likely to be identified as hotspots using micro-scale simulation results. 相似文献
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二氧化硫对人体血淋巴细胞的遗传毒理效应 总被引:8,自引:0,他引:8
孟紫强 《城市环境与城市生态》1994,7(4):17-21
本文对某硫酸厂接触二氧化硫(SO_2)40名工人的外周血淋巴细胞染色体畸变(CA)、姊妹染色单体互换(SCE)、及微核(MN)进行了分析。结果表明,接触SO_2的工人其CA、SCE及MN均显著高于对照组。本文也分析了SO_2在体内的代谢产物──亚硫酸氢钠对淋巴细胞的遗传毒理效应。结果指出,亚硫酸氢钠可诱发人血淋巴细胞CA,SCE及MN,且有明确的剂量效应关系。这些研究证明,SO_2确是人血淋巴细胞染色体断裂剂和基因毒性因子;SO_2与癌症的关系值得进一步研究。 相似文献
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