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21.
赵小龙 《水资源开发与管理》2021,(4):32-38
本文采用高通测序方法对大凌河流域五刺金鱼藻、格菱、狐尾藻、水蓼及芦苇5种水生植物不同季节的微生物群落进行试验分析,分析表明:藻类密度在沉水植物表层要高于浮叶植物表层,微生物群落在浮叶植物根部的结构与其表面存在明显差异。各水生植物的优势生物群落依次为变形菌、梭菌、柔膜菌、鞭脂杆菌、杆菌、疣微菌门,且各微生物群落在季节丰度上存在明显差异性。由此可见,水环境对生物群落的影响要高于植物类型。研究成果可为大凌河流域生态修复工程提供重要理论依据。 相似文献
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官厅水库黑土洼人工湿地系统经过一年多的运行，经历了严寒冬季的考验，获取了1万多组监测数据。通过对BOD5等指标去除率分析，人工湿地对Orth—D、TP、CODMn去除率较多，TN、NH4^＋-N、NO^-3-N处理效果一般。建议二期工程进一步改进工艺，促进有机物的降解。 相似文献
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Kate Sherren;H. M. T. Rahman;Patricia Manuel;Emily Wells;Eric Rapaport;Danika van Proosdij; 《Journal of Flood Risk Management》2024,17(4):e13026
Nature-based coastal adaptation is a subset of nature-based solutions that has to this point focused on the materiality of managing coastal risks: what our coastal protections are made of or where we put things that are in the way of harm. In our collaborative interdisciplinary work, we have been reimagining nature-based coastal adaptation to start with first principles: how we think about the coast and what makes a good coastal life. In a nature-based approach our shared sense of what is good and possible, also known as the social imaginary, needs shifting before any physical material. This paper presents a new nested framework for thinking about nature-based coastal adaptation using five words starting with R: Reimagine, Reserve, Relocate, Restore, Reinforce. We use the nature-based adaptation option of managed dyke realignment in Bay of Fundy agricultural dykelands to illustrate the utility of the framework in practice but assert its more generic applicability. 相似文献
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New Source Review (NSR) is a Clean Air Act regulation that requires electric utilities to meet emission standards when making modifications to existing power plants. The regulation increases the cost of replacing worn out parts, and limits the firm’s scope of potential capital investments. Such restrictions may lead to greater retirements and lower utilization, adversely affecting profits. Prior to the 2000 presidential election, investors expected Bush to have a narrower interpretation of NSR than Gore. Therefore, we use changes in stock prices to estimate the effect on profits of differences in NSR policy. Our results indicate that investors expected the average boiler to be $38 million more valuable under the Bush administration. Over the boilers’ lifetimes, the additional utilization will have increased emissions by 19 million tons of sulfur dioxide, 5.9 million tons of nitrogen oxides and 980 million tons of carbon dioxide, relative to natural gas generation. 相似文献
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滇池湿地现状及保护对策 总被引：3，自引：2，他引：3
湿地可以看作是一个内部过程长期为水控制的水—陆过渡的复合生态系统。滇池湿地具有重要而又独特的环境功能,蕴含着多样性的生物资源。近年来,滇池湿地生态严重退化,质量功能下降。本文通过分析滇池湿地退化现象和原因,提出了滇池湿地资源保护对策。 相似文献
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Use of biofuels diminishes fossil fuelcombustion thereby also reducing net greenhousegas emissions. However, subsidies are neededto make agricultural biofuel productioneconomically feasible. To explore the economicpotential of biofuels in a greenhouse gasmitigation market, we incorporate data onproduction and biofuel processing for thedesignated energy crops switchgrass, hybridpoplar, and willow in an U.S. AgriculturalSector Model along with data on traditionalcrop-livestock production and processing, andafforestation of cropland. Net emissioncoefficients on all included agriculturalpractices are estimated through crop growthsimulation models or taken from the literature. Potential emission mitigation policies ormarkets are simulated via hypothetical carbonprices. At each carbon price level, theAgricultural Sector Model computes the newmarket equilibrium, revealing agriculturalcommodity prices, regionally specificproduction, input use, and welfare levels,environmental impacts, and adoption ofalternative management practices such asbiofuel production. Results indicate no rolefor biofuels below carbon prices of $40 perton of carbon equivalent. At these incentivelevels, emission reductions via reduced soiltillage and afforestation are more costefficient. For carbon prices above $70,biofuels dominate all other agriculturalmitigation strategies. 相似文献
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《International Journal of Tourism Research》2018,20(2):191-203
This study conceptualizes ecotourism behavior as a multidimensional construct and develops a framework that offers a reliable and valid scale to assess ecotourism behavior; the framework is based on an empirical survey using 3 studies. In Study 1, measurement items are established and refined using a literature review, content analysis, and the fuzzy Delphi method. In Study 2, a research instrument is developed, and its reliability and validity are tested. In Study 3, cross‐validation of this research instrument is employed to assess ecotourism behavior using two populations of ecotourists. A reliable and valid 30‐item scale with a seven‐construct model is developed based on Taiwan's forests and wetlands as ecotourism destinations. This research instrument provides researchers with an invaluable instrument to accurately measure ecotourism behavior and offers a theoretical framework for researchers, decision makers, managers, and tourists in the field of ecotourism; thus, it makes a significant contribution to the literature. 相似文献
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本文探讨水生植物对生活污水的净化作用,它主要有沉降悬浮物、吸收营养物质、吸收重金属等直接作用和为根际提供氧气使微生物有效降解有机物的间接作用等。为建立人工生态系统治理生活污水提供科学参考。 相似文献