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多场环境下等截面结构性能分析及优化设计
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作者 柯庆镝 谢敏 +1 位作者 李乾坤 田亚明 《计算机集成制造系统》 EI CSCD 北大核心 2021年第3期857-867,共11页
针对机电产品在多场环境中的结构部件优化问题,提出了基于微分单元的零件等截面优化设计方法。结合等截面结构特性及有限元分析方法,构建了零件等截面模型及性能表达,并基于多场服役环境下(如温度场、静力场等)性能需求,分析了零件等截... 针对机电产品在多场环境中的结构部件优化问题,提出了基于微分单元的零件等截面优化设计方法。结合等截面结构特性及有限元分析方法,构建了零件等截面模型及性能表达,并基于多场服役环境下(如温度场、静力场等)性能需求,分析了零件等截面拓扑变化与其性能变化之间的映射关系,尤其针对其强度需求,建立了其截面结构惯性矩演化过程模型,提出了多场服役性能需求下零件等截面优化设计方法。结合某型号制冷类产品中门体饰条零件,分析了其结构截面拓扑形状,提出了满足其各类服役性能需求的优化截面结构,验证了所提方法的有效性。 展开更多
关键词 多场环境 等截面结构 性能分析 结构优化 机电产品
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承压破碎煤体碎胀系数演变特征与机制 被引量:23
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作者 褚廷湘 李品 +2 位作者 晁江坤 余明高 韩学锋 《煤炭学报》 EI CAS CSCD 北大核心 2017年第12期3182-3188,共7页
利用自制的承压破碎煤体渗流及自燃测试装置,实验测试及分析了破碎煤体在应力、应力-温度、应力-水分不同条件下的碎胀系数的演变特征与机制。研究结果表明:(1)煤样随着应力增加,碎胀系数变化具有明显的阶段性,且随应力变化服从负指数... 利用自制的承压破碎煤体渗流及自燃测试装置,实验测试及分析了破碎煤体在应力、应力-温度、应力-水分不同条件下的碎胀系数的演变特征与机制。研究结果表明:(1)煤样随着应力增加,碎胀系数变化具有明显的阶段性,且随应力变化服从负指数变化规律;(2)在相同的轴压下,碎胀系数随温度升高而增加,热膨胀效应明显,说明采空区煤自燃的热效应将造成破碎煤体的碎胀系数增大,堆积更为松散;(3)当破碎煤体外在水分含量增加,在相同的轴压情况下,碎胀系数随外在水分增加而增加。说明随着采空区破碎煤体外在水分的增加,破碎煤体的碎胀系数将增大;(4)破碎煤体在应力、热膨胀及湿膨胀作用下,堆积体内部颗粒发生相对移动、二次破碎、颗粒自组织再堆积,致使应力-应变曲线发生变化,进而影响其碎胀系数。 展开更多
关键词 采空区 破碎煤体 碎胀系数 多场环境
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Reservation Based Optimal Parking Lot Recommendation Model in Internet of Vehicle Environment 被引量:5
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作者 FUJiabin CHEN Zhenxiang +1 位作者 SUN Runyuan YANG Bo 《China Communications》 SCIE CSCD 2014年第10期38-48,共11页
In order to solve the problem that the drivers can't find the optimal parking lot timely,a reservation based optimal parking lot recommendation model in Internet of Vehicle(IoV) environment is designed.Based on th... In order to solve the problem that the drivers can't find the optimal parking lot timely,a reservation based optimal parking lot recommendation model in Internet of Vehicle(IoV) environment is designed.Based on the users oriented parking information recommendation system,the model considers subjective demands of drivers comprehensively,makes a deeply analysis of the evaluation indicators.This recommendation model uses a phased selection method to calculate the optimal objective parking lot.The first stage is screening which based on the users' subjective parking demands;the second stage is processing the candidate parking lots through multiple attribute decision making.Simulation experiments show that this model can effectively solve the problems encountered in the process of finding optimal parking lot,save the driver's parking time and parking costs and also improve the overall utilization of parking facilities to ease the traffic congestion caused by vehicles parked patrol. 展开更多
关键词 intelligent parking guidance parking lot recommendation phased selectionmethod evaluation indicators
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Payments for Ecosystem Services: Market Mechanism or Diversified Modes?
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作者 刘艳红 郭朝先 《Journal of Resources and Ecology》 CSCD 2015年第6期420-426,共7页
Payment for ecosystem services is a concept of environmental protection and method of environmental management that has "purchasing conservation" as a major feature and has grown around the world since the 1990 s. I... Payment for ecosystem services is a concept of environmental protection and method of environmental management that has "purchasing conservation" as a major feature and has grown around the world since the 1990 s. It is stressed by the school of environmental economics that as a voluntary mechanism of exchange between ecological service providers and demanders, payments for ecosystem services can help to increase inputs and improve efficiency. Ecological economics holds that the ecological system and the complexity of the policy environment restrict the functional space of market mechanisms. The negative influence of the objective of giving priority to efficiency on environmental protection and social fairness cannot be neglected; therefore, the exchange mechanism is just one type of eco-compensation models. Here, we posit that payments for ecosystem services is a good tool for environmental protection and increases inputs and efficiency. Although payment for ecosystem services is confronted with challenges in application, it is playing an increasingly important role in the field of ecological services with a relatively high degree of commodification. Payments for ecosystem services can also increase the cost effectiveness of publicly managed environmental projects with the cooperation of other policy tools. 展开更多
关键词 payments for ecosystem services market mechanism diversified modes environmental economics ecological economics
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