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通过采集高尔夫球场即将淹没的果岭土壤进行实验室条件下的模拟库基样品试验,对水库扩容后蓄水初期水质的变化情况进行了研究.结果表明:库水所含主要成分pH、高锰酸钾盐指数、总氮、总磷、氨氮和硝酸盐氮分别为7.4(mg/L)、30.8(mg/L)、1.16(mg/L)、1.189(mg/L)、0.21(mg/L)和0.11(mg/L);果岭20 cm土层库基土样pH、有机质、硝酸盐氮、氨态氮和有效磷分别为6.41(mg/kg)、10.29(mg/kg)、25.48(mg/kg)、25.76(mg/kg)和140.77(mg/kg).现有库基成分会改变库水高锰酸钾盐指标的升高.库水本身的总磷和总氮含量就严重超标.果岭库基本身的磷氮含量也很高.浸泡后果岭库基土样对降低浸出物总磷的严重超标起到了对冲的作用,致使总磷含量大为降低. 相似文献
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能源环境管理是各界关注的热点话题,也是科学研究的重要方向.以国家自然科学基金资助能源环境管理领域的科研项目为基础数据信息,本文重点分析了\"十三五\"期间国家自然科学基金在该领域资助项目的总体特征、研究主题和热点变化,并结合新时代科学基金资助导向提出了可能的发展趋势.主要结论包括:①能源环境管理领域面上、青年、地区等自由探索类项目的立项绝对数和学科占比均呈上升趋势,并更多向青年学者倾斜,资助强度保持稳定;②碳、能源和环境是自由探索项目中出现频率最高的热词,与之相关的研究主题随着政策等调整具有动态变化特征;③能源环境管理领域重点、重大等引导类项目和优青、杰青、创新研究群体等人才类项目不断实现突破,增速明显,学科占比优势突出;④问题导向与本土情景、理论体系和一般规律、学科交叉融合,以及市场和微观主体作用是研究选题确立与项目申请时可能需要重点关注的方向. 相似文献
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概述了在辽宁大洼县田庄台抽水站地基处理工程中采用高压喷射注浆技术的实践经验,并介绍了从工程勘察、方案选择、设计、施工和检测的全过程。此项技术,经过长期沉降观测取得了良好的加固成果。 相似文献
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传统的基坑支护结构设计具有相当的模糊性和不确定性,可能危及基坑和周围环境的安全.笔者利用深基坑支护体系的监测数据,采用灰色系统理论建立了基坑工程变形的GM(1,1)预测模型,其模型的两个参数可识别基坑变形发展势态,并由此讨论了模型的适用范围.最后,运用该模型预测分析实际基坑工程支护结构变形,表明其预测模型可用于基坑动态设计与信息化施工. 相似文献
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以某特大铁路简支梁桥为例,考虑m值变化对基础弹性刚度的影响,笔者建立了铁路简支梁桥单墩有限元计算分析模型;运用大型通用软件ANSYS,采用时程分析方法,对不同地震输入激励条件下的桥墩动力响应进行计算研究;研究结果表明,m值变化引起的基础竖向刚度的变化对桥梁结构地震响应的影响较大.笔者的研究成果为硬土质基础的铁路简支梁桥的抗震安全设计,提供了重要参考. 相似文献
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In this paper, we describe a model designed to simulate seasonal dynamics of warm and cool season grasses and forbs, as well as the dynamics of woody plant succession through five seral stages, in each of nine different plant communities on the Rob and Bessie Welder Wildlife Refuge. The Welder Wildlife Refuge (WWR) is located in the Gulf Coastal Prairies and Marshes ecoregion of Texas. The model utilizes and integrates data from a wide array of research projects that have occurred in south Texas and WWR. It is designed to investigate the effects of alternative livestock grazing programs and brush control practices, with particular emphasis on prescribed burning, the preferred treatment for brush on the WWR. We evaluated the model by simulating changes in the plant communities under historical (1974-2000) temperature, rainfall, livestock grazing rotation, and brush control regimes, and comparing simulation results to field data on herbaceous biomass and brush canopy cover collected on the WWR over the same period. We then used the model to simulate the effects of 13 alternative management schemes, under each of four weather regimes, over the next 25 years. We found that over the simulation period, years 1974-2000, the model does well in simulating the magnitude and seasonality of herbaceous biomass production and changes in percent brush canopy cover on the WWR. It also does well in simulating the effects of variations in cattle stocking rates, grazing rotation programs, and brush control regimes on plant communities, thus providing insight into the combined effects of temperature, precipitation, cattle stocking rates, grazing rotation programs, and brush control on the overall productivity and state of woody plant succession on the WWR. Simulation of alternative management schemes suggests that brush canopy removal differs little between summer and winter prescribed burn treatments when precipitation remains near the long-term average, but during periods of low precipitation canopy removal is greater under winter prescribed burning. The model provides a useful tool to assist refuge personnel with developing long-term brush management and livestock grazing strategies. 相似文献
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Laura Kunz 《Journal of Environmental Planning and Management》2010,53(5):657-676
This paper analyses CO2 emissions reduction costs based on project data from the Climate Cent Foundation (CCF), a climate policy instrument in Switzerland. Four conclusions are drawn. First, for the projects investigated, the CCF on average pays €63/ton. Due to the Kyoto Protocol, the CCF buys reductions only until 2012. This cut-off increases reported per ton reduction costs, as the additional lifetime project costs are set in relation to reductions only until 2012, rather than to reductions realised over the whole lifetime. Lifetime reduction costs are €45/t. Second, correlation between CCF's payments and lifetime reduction costs per ton is low. Projects with low per ton reduction costs should thus be identified based on lifetime per ton reduction costs. Third, the wide range of project costs per ton observed casts doubts on the widely used identification of the merit order of reduction measures based on average per ton costs for technology types. Finally, the CCF covers only a fraction of additional reduction costs. Decisions to take reduction efforts thus depend on additional, non-observable and/or non-economic motives. Any generalisation of results has to consider that this analysis is based on prospective costs of a sub-sample of projects in Switzerland. 相似文献
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本文基于国家自然科学基金环境化学学科的项目申请与资助数据,系统分析了该学科2014—2023年在资助总量、经费流向、研究热点等方面的趋势与变化,主要研究发现:①申请数增速超过资助数增速,导致资助率从2014年的27.9%降至2023年的18.6%,反映科研竞争日益激烈. ②自由探索类项目资助经费在学科资助总经费中的占比从80.0%降至55.2%,重点类和人才类项目资助经费占比则显著增加,显示出环境化学学科越发重视具有战略性和高创新潜力的研究. ③环境分析化学和水污染控制化学等领域的资助经费呈增长趋势,资助数也较高,反映其与当前社会需求的密切关联. ④污染物处理和环境质量监测是环境化学领域中的核心问题,科研人员正通过应用纳米技术研发新材料,来提高污染控制的效率并促进环境污染修复. 本研究不仅为环境化学学科的未来发展提供了数据支持,也为相关科研人员选择研究方向、制定项目申请策略提供了有益的参考. 相似文献