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981.
应用非水电位滴定法测定了废水中各种烷基磷酸酯钾盐及其单、双酯盐。方法的变异系数分别为2.3%和7.8%(n=12)。本法可有效地消除非离子表面活性剂的干扰,适用于化纤油剂的质量检验和上油槽中油剂浓度的测定。  相似文献   
982.
关于风景评价中心理物理学方法局限性的探讨   总被引:2,自引:0,他引:2  
由于对西方风景评价理论和方法缺乏足够的了解和深入的研究,现今国内对其中的心理物理学方法及其作用产生了一些误解。本文在扼要介绍了心理物理学派的主要方法思路之后,着重对该学派所存在的重大理论缺陷和方法局限性做了较深入的分析。  相似文献   
983.
应用新的资源价值观念与环境经济学中MOC框架及其它理论,给出了建材资源的生态环境补偿费的定义与确定方法,建立了相应的理论模型。在此基础上,根据不同地区的经济发展水平与环境现状等实现情况,用认可系数对计算的补偿费进行修正。  相似文献   
984.
通过对秦皇岛市4种常见绿化植物的叶片滞尘量、单株滞尘能力及相关因素的研究,发现绿化植物单位叶面积的滞尘量最大可以相差2.5倍左右,树种叶片滞尘能力的大小排序为:国槐>悬铃木>金银木>连翘,单株滞尘能力的大小排序为:悬铃木>国槐>金银木>连翘;绿化植物的滞尘量与环境中粉尘含量成正比,树木滞尘能力还与叶片表面性状、叶面积指数及植物所处环境等因素有关。  相似文献   
985.
外来赤潮生物入侵现状及对赤潮灾害的影响研究   总被引:1,自引:0,他引:1  
外来赤潮生物入侵加剧了我国近海海域的赤潮灾害。根据2004—2013年的数据统计,分别从赤潮生物优势种、频率、海域分布和赤潮面积4个方面分析了外来赤潮生物对我国近海赤潮灾害的影响,并着重从外来赤潮生物入侵早期预警系统建设、压舱水排放管理和赤潮灾害防治技术3个方面提出应对措施。  相似文献   
986.
Water is a natural resource key to human and environmental health. China has suffered serious contamination of its water sources in the past decade, which has had severe consequences on the water supplies of millions of residents. Frequent polluting accidents and the amount of wastewater discharged have caused concern for the safety of drinking water. Fortunately, those at various levels of government have realized the importance of protecting the sources of drinking water and confirmed a list of 175 nationally important sources. Measures have also been adopted to control water pollution, including infrastructural, physical, chemical, ecological, administrative, and legal measures. While helpful, some areas in need of more attention are rural water, groundwater, agricultural pollution, and domestic sewage. Based on the lessons learned from experiences in developed countries, we offer some suggestions for improving, inter alia, funding, legal construction, management, and awareness‐raising, as well as present proposals for the future protection of our sources of drinking water. Future work should focus on water quality standards, quantitative research, high technology and legislation.  相似文献   
987.
Sedimentation is emerging as a key issue in sustainable reservoir management. One approach to controlling reservoir sedimentation is to trap sediment in hydraulic structures upstream of the reservoir. In the 1,163‐km2 catchment of the Dahan River (Taiwan) over 120 “sabo” dams were built to reduce sediment yield to Shihmen Reservoir. Built in 1963 for water supply, Shihmen has lost over 40% of its 290‐Mm3 storage capacity to sedimentation. Most of these upstream structures were small, but three had capacities >9 Mm3. Field measurements and historical data from the Water Resources Agency show most smaller dams had filled with sediment by 1976. The three largest were full or nearly so by 2007, when one (Barlin Dam) failed, releasing a pulse of 7.5 Mm3, most of its 10.4 Mm3 stored sediment downstream. The Central Range of Taiwan is rapidly eroding (denudation rates 3‐6 mm/yr), so geologically high loads make sediment problems manifest sooner. Even in other environments, however, eventually small dams built upstream of large reservoirs are likely to fill themselves, creating multiple small sediment‐filled reservoirs, some located in sites inaccessible to mechanical removal. Our analysis suggests sabo dams do not offer a long‐term basis for controlling reservoir sedimentation in such a high‐sediment yield environment. Sustainable solutions must somehow pass sediment downstream, as would be accomplished by a sediment bypass around Shihmen Reservoir, as now being studied.  相似文献   
988.
提出一种新纳米零价铁反应器(Nanoscale Zero-Valent Iron Reactor,简称NIR)及"混凝沉淀+纳米零价铁"处理工艺,通过实际生产废水进行中试,考察和研究该工艺和NIR技术处理江苏省某市印刷电路板(Printed Circuit Board,简称PCB)工业园区废水的效果。结果表明,此工艺对PCB生产废水中Cu、TP及COD Cr去除率分别可达到97.3%、73.7%、26%,其中Cu处理效果最佳;XRD结果表明,纳米零价铁(Nanoscale Zero-Valent Iron,nZVI)与PCB生产废水反应后含有γ-Fe2O3、Fe3O4、γ-FeOOH、CuO、Cu2O、Cu0等产物。"混凝沉淀+纳米零价铁"工艺处理废水时具有处理效果好、工艺耐冲击性能好、产泥量小、不易造成二次污染等优点。  相似文献   
989.
Wildlife incidents with aircraft cost the United States (U.S.) civil aviation industry >US$1.4 billion in estimated damages and loss of revenue from 1990 to 2009. Although terrestrial mammals represented only 2.3 % of wildlife incidents, damage to aircraft occurred in 59 % of mammal incidents. We examined mammal incidents (excluding bats) at all airports in the Federal Aviation Administration (FAA) National Wildlife Strike Database from 1990 to 2010 to characterize these incidents by airport type: Part-139 certified (certificated) and general aviation (GA). We also calculated relative hazard scores for species most frequently involved in incidents. We found certificated airports had more than twice as many incidents as GA airports. Incidents were most frequent in October (n = 215 of 1,764 total) at certificated airports and November (n = 111 of 741 total) at GA airports. Most (63.2 %) incidents at all airports (n = 1,523) occurred at night but the greatest incident rate occurred at dusk (177.3 incidents/hr). More incidents with damage (n = 1,594) occurred at GA airports (38.6 %) than certificated airports (19.0 %). Artiodactyla (even-toed ungulates) incidents incurred greatest (92.4 %) damage costs (n = 326; US$51.8 million) overall and mule deer (Odocoileus hemionus) was the most hazardous species. Overall, relative hazard score increased with increasing log body mass. Frequency of incidents was influenced by species relative seasonal abundance and behavior. We recommend airport wildlife officials evaluate the risks mammal species pose to aircraft based on the hazard information we provide and consider prioritizing management strategies that emphasize reducing their occurrence on airport property.  相似文献   
990.
Scientific interpretation of the relationships between urban landscape patterns and water quality is important for sustainable urban planning and watershed environmental protection. This study applied the ordinary least squares regression model and the geographically weighted regression model to examine the spatially varying relationships between 12 explanatory variables (including three topographical factors, four land use parameters, and five landscape metrics) and 15 water quality indicators in watersheds of Yundang Lake, Maluan Bay, and Xinglin Bay with varying levels of urbanization in Xiamen City, China. A local and global investigation was carried out at the watershed-level, with 50 and 200 m riparian buffer scales. This study found that topographical features and landscape metrics are the dominant factors of water quality, while land uses are too weak to be considered as a strong influential factor on water quality. Such statistical results may be related with the characteristics of land use compositions in our study area. Water quality variations in the 50 m buffer were dominated by topographical variables. The impact of landscape metrics on water quality gradually strengthen with expanding buffer zones. The strongest relationships are obtained in entire watersheds, rather than in 50 and 200 m buffer zones. Spatially varying relationships and effective buffer zones were verified in this study. Spatially varying relationships between explanatory variables and water quality parameters are more diversified and complex in less urbanized areas than in highly urbanized areas. This study hypothesizes that all these varying relationships may be attributed to the heterogeneity of landscape patterns in different urban regions. Adjustment of landscape patterns in an entire watershed should be the key measure to successfully improving urban lake water quality.  相似文献   
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