共查询到20条相似文献,搜索用时 15 毫秒
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Triaxial compression rheological experiments on carbonaceous slate specimens of deep buried tunnel were carried out on the rock rheology testing machine. Along with the increase of loading stress level and the improvement of moisture conditions, the initial attenuation creep phase, the stabilization creep phase, and the speedup creep phase were produced. By connecting Burgers model and the nonlinear viscoplastic body consisted of nonlinear viscous component η(n,t) parallel connected with the plastic component in series, the improved model could describe the speedup creep phase. Using this model to fit and analyze the rheological parameters of different moisture conditions, it is shown that η〖KG0.005mm〗 M、E M、E K and η〖KG0.005mm〗 Kwill decrease with negative exponential trend. Then water damage D(w) was introduced, and through deriving damage evolution equation, the nonlinear viscoelasticplastic model with water damage effect was established. Finally, the time effect deformation of surrounding rock under different times and different moisture conditions was studied by numerical simulation, and the results show that primary support should close in 168 h, and the best construction time for secondary lining is 360 h after the primary support is closed. 相似文献
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Owing to the fluctuation of water quality in urban river which polluted by drainage along river, one-dimension uncertain water quality model embeded neural network is established. Genetic algorithms and a modified fitness function are used to optimize parameters of the uncertain model. Examples illustrate that the uncertain model has higher prediction accuracy with the average accuracy over 80% than the certain model, and is more sensitive to the fluctuation of pollutants discharged into the river. The uncertain model has a significant advantage of prediction and could better adapt to the changing urban water environment, especially at points close to the pollution sources. 相似文献
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根据1990—2016年东平湖主要水文站的实测水文数据,采用Spearman秩相关系数法,分析了东平湖水位以及主要水质指标的年际变化特征,阐述了东平湖水位与水质的相关性,并探讨了南水北调东线工程实施后长期的高位蓄水状态下东平湖湖泊水质的可能变化情况。结果表明:1990—2016年东平湖年平均水位呈波动上升趋势;湖水位变化与TP、高锰酸盐指数浓度呈显著负相关,相关系数分别为 -0.685和-0.550;与COD浓度呈负相关,相关系数为-0.389,相关性较弱;TN浓度主要受大汶河入湖污染量的控制;南水北调东线工程在一定程度上改善了东平湖的水质,但并未根治其水环境问题。建议通过合理调控东平湖水位高度、降低湖区人类活动强度等措施来管理湖泊水质,以期满足南水北调水质要求、实现东平湖乃至黄河下游湖泊生态系统的可持续发展。 相似文献
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Dai Dayu Xu Mingxi Peng Qingchu 《保鲜与加工》1993,(3):99-103
The status quo of heauy-metals pollution in water phase of course of Long-Tan hydropower statian was eualuated by water Quality Standand Level Method. With this special method,mone objectiue and definite results were obtained. 相似文献
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梁多 《农产品加工.学刊》2007,(5):18-19,22
液态鸡蛋产品在一些发达国家已相当普遍。我国是世界上鸡蛋产量和消费量最大的国家,然而液态鸡蛋产品在我国尚属空白。着重介绍目前对液态鸡蛋杀菌方法的研究进展,以期对我国的液态蛋生产提供参考。 相似文献
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周丛藻类在水质监测及净化中应用的研究进展 总被引:1,自引:1,他引:0
近年来水质污染问题逐渐引起人们的密切关注,应用生态环境工程进行水质的检测与修复得到广泛应用。周丛藻类在水环境中广泛存在,并对水质变化极其敏感,所以在检测水质的同时检测周丛藻类的群落变化,能更全面监测水质变化;同时,因为周丛藻类的耐污性或敏感性的不同,也会对一些特殊的化学成分变化特别敏感,体现出指示作用。另外,周丛藻类对水体中的一些污染物如氮、磷及一些重金属离子等具有较好的吸附与去除作用,提示周丛藻类在水质净化中同样具有很高的应用价值。本研究就对今年来周丛藻类在水质监测及净化中应用的研究进展作一综述。 相似文献
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《保鲜与加工》2003,(11):121-125
ased on the average depth's momentum equation of two dimension which observe the momentum conservation,the numerical simulation of velocity distribution in aha reservoir is presented. According to the property of pollutant while they are in convective diffusion or transplant and degradation, the model simulates organics convective diffusion and heavy metal transplantion. In the end, some forecast are presented for typical organics and heavy metal pollutant at abundant season and medium season in the future of ten years and some proposal are given for dispose. 相似文献
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麦类作物水肥耦合研究进展 总被引:1,自引:1,他引:1
简述了国内外近些年麦类作物水肥耦合研究的结果,总结了水肥耦合的含义、水肥耦合效应对麦类作物生长发育、产量,水肥利用率,光合及生理特性、土壤养分变化及作物品质的影响。提出了今后的研究方向。 相似文献
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Based on the two-dimensional hydrodynamic model,the two-dimensional water quality model is presented in this paper.According to the numerical simulation and analysis of water environment quality at different frequency floodwater,it concludes that the flood runoff is the first factor for the water environment quality,and points out that the water environment quality is better in low frequency flood than that in high frequency in respect of organic contamination,in addition,the concentration of heavy metal in high frequency flood tends to be increased greatly. 相似文献
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为了探明在超高产条件下椒样薄荷高产优质的农艺模型以及对其精油品质的影响,采用三因子二次饱和D最优设计方案,选取对椒样薄荷精油产量影响较大的密度X1、氮肥用量X2、磷肥用量X3为调控因子,以每公顷精油产量Y为目标函数,研究椒样薄荷栽培数学模型。结果表明,影响椒样薄荷精油产量的各因素权重依次为氮肥用量X2>密度X1>磷肥用量X3,依据建立的模型,目标精油产量≥100.5 kg•hm-2时优质高产最佳农艺方案为:密度X117.55~22.05万苗﹒hm-2,氮肥用量X2纯N172.5~217.5kg﹒hm-2,磷肥用量X3纯P2O5 118.5~150kg﹒hm-2;品质分析结果表明,密度对精油品质有显著影响,氮肥用量对精油品质的影响与密度密切相关,在密度较低时影响不明显,而在密度较高时有一定的影响,适量控氮可以提高精油品质,过量施氮会降低精油品质,磷肥用量对精油品质影响不明显。 相似文献
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不同有机物料水稻育秧基质的持水性 及对水稻秧苗素质的影响 总被引:6,自引:2,他引:6
为探讨不同有机物料水稻育秧基质的持水性及对水稻秧苗素质的影响,以‘龙稻11号’为供试品种,采用秸秆和稻壳为有机物料与有机肥、草炭、沸石、蛭石、细河沙、碳粉等按不同配比混合,进行有机物料育秧基质的水稻育秧试验。结果表明,有机物料育秧基质的容重与最大持水量呈极显著负相关、不同有机物料育秧基质的失水率在一定范围内都可以满足育秧要求。CO1C为最优基质,基质栽培期间无病虫害发生且所育水稻苗素质最好,达到壮秧效果。利用有机物料配制的育秧基质符合机插秧苗的要求且具有良好的壮秧效果,可以代替普通土壤应用于水稻育秧生产中。 相似文献
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作物气孔导度模型研究进展及应用现状 总被引:1,自引:0,他引:1
旨在为作物耗水和碳水交换相关研究的模型选择提供理论指导,本研究归纳了气孔导度对单一和综合环境因子的响应情况;对现有气孔导度模型进行了分类和比较,包括基于Jarvis模型建立和改进的经验模型、基于BWB模型建立和改进的半经验模型、基于ABA调控建立和改进的模型、基于保卫细胞膨压控制理论建立和改进的模型;并概述了气孔导度模型在作物水分利用研究领域的应用,以叶片气孔导度和冠层导度的定量关系为切入点建立多尺度联合的机理模型将是未来作物耗水尺度拓展研究的热点。 相似文献