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Application of decision tree to selection of MTBM for adverse geological conditions 被引量:1
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作者 Jafarimoghaddam Alireza Khademi Hamidi Jafar Najaf Mohammad 《International Journal of Mining Science and Technology》 SCIE EI 2013年第4期499-507,共9页
So many potential risks can be identifed for application of trenchless technology especially using microtunneling methods.Unexpected changes in ground conditions,such as encountering boulders,tree roots,ground water a... So many potential risks can be identifed for application of trenchless technology especially using microtunneling methods.Unexpected changes in ground conditions,such as encountering boulders,tree roots,ground water and man-made structures such as old foundations are the principal geotechnical risks,which affect the selection of an appropriate microtunnel boring machine.On the other hand,the performance of each microtunneling technique will differ while encountering such conditions.Hence,predicting the potential hazards provides a better safety and risk management plan.In this study,a couple of potentially hazardous situation,which are commonly associated with ground conditions,were identifed and investigated.A decision tree aid methodology was proposed based on geotechnical risk assessment for selection of proper microtunneling technique.Based on the approach the most appropriate microtunneling technique has the minimum risk level either before or after hazards mitigation measures.In order to check the effciency of the approach in practice,selection of microtunnel boring machine for Hamadan sewerage pipeline project was evaluated.Accordingly,an earth pressure balance(EPB)MTBM was selected for the project. 展开更多
关键词 Trenchless technology Microtunnel boring machine(MTBM) Diffcult ground conditions Geotechnical risk Decision tree
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基于仿生树形相变循环散热技术研究及变频空调应用
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作者 张传美 王定远 +1 位作者 葛睿彤 裴玉哲 《家电科技》 2024年第1期28-31,65,共5页
伴随环境温度升高,空调制冷量需求也会逐步增高,从而引发变功率模块发热严重,导致其内部芯片无法良好散热。通常采用压缩机降频工作方法保证电控板安全,但该方法的缺点是温度越高,空调制冷能力越差。针对该缺点,提出一种仿生树形的单向... 伴随环境温度升高,空调制冷量需求也会逐步增高,从而引发变功率模块发热严重,导致其内部芯片无法良好散热。通常采用压缩机降频工作方法保证电控板安全,但该方法的缺点是温度越高,空调制冷能力越差。针对该缺点,提出一种仿生树形的单向相变循环传热方法,开发了一款单向循环相变风冷散热器,通过焓差室测试,实现了散热器进风口温度62℃时,变频功率模块温度可以降低8℃以上,防止压缩机强制降频造成制冷量衰减。 展开更多
关键词 多联机 变频空调 变频模块 高温制冷 仿生树形 相变散热 单向循环
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新型土壤调理剂对安徽砀山桃树缺铁黄化的矫治效果研究 被引量:1
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作者 孟云杉 范再碧 +3 位作者 杜学军 高子登 任雪芹 胡树文 《江西农业大学学报》 CAS CSCD 北大核心 2022年第5期1135-1143,共9页
【目的】缺铁黄化是一个全球性的难题,全球大约有 40%的土壤上生长的植物容易出现缺铁黄化症,其中,桃树比较容易发生缺铁黄化病。导致桃树缺铁黄化因子较多,因此,深入研究引起桃树缺铁黄化的原因对制定有效防治措施具有重要意义。【方... 【目的】缺铁黄化是一个全球性的难题,全球大约有 40%的土壤上生长的植物容易出现缺铁黄化症,其中,桃树比较容易发生缺铁黄化病。导致桃树缺铁黄化因子较多,因此,深入研究引起桃树缺铁黄化的原因对制定有效防治措施具有重要意义。【方法】研究基于安徽砀山桃区的缺铁黄化问题,通过施用土壤调理剂和螯合 Fe肥,在桃上市期对桃区的土壤、叶片和桃样品进行采样,对安徽砀山土壤理化性质、养分和叶片营养元素以及果实品质等指标进行测定和分析。探究桃树缺铁黄化的主导因子并评价其矫治效果。【结果】(1)土壤高 pH、高HCO_(3)^(-)含量和高盐分是当地桃树缺铁黄化的主导因子,pH 较高抑制了土壤中铁的有效性。(2)施用调理剂和螯合 Fe肥使得黄化症状显著改善,主要表现在土壤中的 pH、EC、HCO_(3)^(-)和 Cl^(-)含量降低和有效 Fe含量增多,全 N 和速效 P 含量降低,叶片中的活性 Fe 和叶绿素含量增多,N 和 P 元素含量降低。【结论】施加土壤调理剂和螯合 Fe肥均能不同程度地改善果树黄化问题。综合来看,施用 2 250 kg/hm^(2)的土壤调理剂(T3 处理)对增加土壤、叶片有效Fe及提升叶绿素含量和果实品质效果最佳。 展开更多
关键词 土壤调理剂 桃树 缺铁黄化 营养元素 矫治
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导致汽车空调不制冷的故障原因统计与分析 被引量:2
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作者 牛华 《时代汽车》 2020年第23期167-168,共2页
进入夏天后,汽车的空调故障频率增高。但其封闭且复杂的结构导致了许多故障现象和原因之间的关系非常不清楚和盘根错节,因此维修人员无法及时、科学地确定故障原因。为了快速准确地诊断汽车空调的故障,本文以空调不制冷故障为例,引入故... 进入夏天后,汽车的空调故障频率增高。但其封闭且复杂的结构导致了许多故障现象和原因之间的关系非常不清楚和盘根错节,因此维修人员无法及时、科学地确定故障原因。为了快速准确地诊断汽车空调的故障,本文以空调不制冷故障为例,引入故障树分析法,对该故障建立了故障树,并对其进行了定性分析和定量计算,利用分析结果为故障诊断流程设计提供理论依据,为进一步开发汽车空调自动诊断仪奠定了理论基础。 展开更多
关键词 汽车空调 不制冷 故障树 定性分析 定量分析
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汽车空调左右吹面出风口出风温度差异分析
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作者 陈俊 肖天平 《汽车电器》 2016年第10期60-62,共3页
某车型在夏季路试空调开启模式下,左右吹面出风口出风温度有差异。利用问题分析树等手段,通过分析蒸发器的冷媒流动路径以及温度分布试验发现了问题的原因。最终通过两组模拟试验证明了蒸发器为问题的主要原因,为后续工程开发积累了宝... 某车型在夏季路试空调开启模式下,左右吹面出风口出风温度有差异。利用问题分析树等手段,通过分析蒸发器的冷媒流动路径以及温度分布试验发现了问题的原因。最终通过两组模拟试验证明了蒸发器为问题的主要原因,为后续工程开发积累了宝贵的经验。 展开更多
关键词 空调制冷系统 出风温度差异 冷媒流动路径 分析树
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Learning from the crowd:Road infrastructure monitoring system 被引量:2
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作者 Johannes Masino Jakob Thumm +1 位作者 Michael Frey Frank Gauterin 《Journal of Traffic and Transportation Engineering(English Edition)》 2017年第5期451-463,共13页
The condition of the road infrastructure has severe impacts on the road safety, driving comfort, and on the rolling resistance. Therefore, the road infrastructure must be moni- tored comprehensively and in regular int... The condition of the road infrastructure has severe impacts on the road safety, driving comfort, and on the rolling resistance. Therefore, the road infrastructure must be moni- tored comprehensively and in regular intervals to identify damaged road segments and road hazards. Methods have been developed to comprehensively and automatically digitize the road infrastructure and estimate the road quality, which are based on vehicle sensors and a supervised machine learning classification. Since different types of vehicles have various suspension systems with different response functions, one classifier cannot be taken over to other vehicles. Usually, a high amount of time is needed to acquire training data for each individual vehicle and classifier. To address this problem, the methods to collect training data automatically for new vehicles based on the comparison of trajectories of untrained and trained vehicles have been developed. The results show that the method based on a k-dimensional tree and Euclidean distance performs best and is robust in transferring the information of the road surface from one vehicle to another. Furthermore, this method offers the possibility to merge the output and road infrastructure information from multiple vehicles to enable a more robust and precise prediction of the ground truth. 展开更多
关键词 Road infrastructure condition Monitoring tree graphs Euclidean distance Machine learning Classification
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