共查询到20条相似文献,搜索用时 56 毫秒
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基于可变模糊聚类迭代模型的溃坝生命损失预测 总被引:1,自引:0,他引:1
针对我国溃坝相关资料缺乏、数据均匀连续性较差的现状,将可变模糊集理论引入到溃坝生命损失预测中,建立基于可变模糊聚类(VFC)循环迭代模型的人口死亡率预测模型。采用相邻模糊标度法确定指标权重,运用模型得到最优相对隶属度矩阵和最优聚类中心矩阵,结合欧氏距离,对样本进行二次筛选,再运用指数加权平均法,计算得到待估样本人口死亡率估计值。实例验算证明,该模型符合我国现状,具有一定的实用性和较高的精度。 相似文献
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基于GIS的溃坝救助支持系统设计与研究 总被引:2,自引:1,他引:1
以溃坝洪水数值模拟和地理信息系统技术作支持,设计了溃坝救助支持系统的总体结构框架及系统各模块的功能和运算流程.在实现溃坝洪水数值模拟结果和其他基础地理信息可视化的基础上,规划了应急物资的调度、避难场所和撤离路径.依据各种救灾物资和设施的服务范围划分救灾单元,并计算出各救灾单元的人力物力配置情况,实现了资源的优化配置.系统的建立为溃坝救助提供了科学依据,具有较高的实用价值. 相似文献
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The low rate (C/33) discharge data obtained from a calendar life study were numerically analyzed with a single particle model. The simulation showed that the stoichiometric window for the cathode shrank with capacity fade. The change of the stoichiometric window for the anode was more complicated. The aged anode became less charged when the capacity fade was caused mostly by the loss of cyclable lithium ions. The anode would be charged to a higher stoichiometric number (or state of charge, SOC) when the capacity fade became controlled by the loss of active material in the anode. 相似文献
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A review of the electrochemical performance of alloy anodes for lithium-ion batteries 总被引:2,自引:0,他引:2
Wei-Jun Zhang 《Journal of power sources》2011,196(1):13-24
Alloy anodes are promising anode materials for lithium-ion batteries due to their high-energy capacity and safety characteristics. However, the commercial use of alloy anodes has been hindered to date by their low cycle life and high initial capacity loss. This review highlights the recent progress in improving and understanding the electrochemical performance of various alloy anodes. The approaches used for performance improvement are summarized, and the causes of first-cycle irreversible capacity loss are discussed. The capacity retentions and irreversible capacity losses of various alloy anodes are compared. Several alloy anodes exhibited excellent cycle life (up to 300 cycles) with high initial coulombic efficiency (80-90%) and large reversible capacity (500-700 mAh g−1). 相似文献
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为了评价燃料电池混合动力系统能量管理策略的经济性,对基于状态机和模糊逻辑2种能量管理策略的燃料电池混合动力叉车的价值损耗进行分析。首先,通过分析燃料电池和锂电池的工作特性,分别构建依赖实际工况的燃料电池单体电压衰减率模型和锂电池容量衰减率模型;同时定义计及燃料电池氢耗量的燃料电池混合动力系统的综合价值损耗指标。其次,通过测试叉车极限工况,计算燃料电池功率和锂电池容量,并根据母线电压确定锂电池SOC范围。最后,设计基于状态机和模糊逻辑的2种燃料电池混合动力叉车能量管理策略,并通过仿真分析在叉车一次循环工况下2种能量管理的价值损耗。研究结果表明:相较于模糊逻辑策略,采用状态机策略造成燃料电池寿命损耗提高7.81%,氢耗量提高1.89倍,锂电池寿命损耗减小21.33%。 相似文献
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锅炉炉内承压部件的蠕变分析及寿命计算 总被引:4,自引:0,他引:4
以高温过热器为例,对锅炉炉内承压部件的寿命损耗规律进行了分析,采用拉森-米勒参数式确定蠕变断裂时间,用罗宾逊法则求出过热器蠕变寿命损耗,同时考虑疲劳对高温金属的破坏作用,最终得到适用于在线监测系统的过热器蠕变寿命简化计算公式。在计算管壁应力时,取额定负荷下的工质压力作为恒定的工作压力,这种处理使计算得到简化并趋于安全。高温腐蚀的影响通过原始壁厚乘以一个修正系数考虑。现场直接测量过热器管壁温度信号,经过适当的补偿和修正,就可输入在线监测系统进行寿命损耗监测。参5 相似文献
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本研究在调查三门峡渭河库区淹没范围(潼关断面水位335m,入库流量分别为50年遇和100年遇洪水时的水面线以下的地面。)载物社会经济状态的基础上,依据洪灾损失计算理论,重点分析了三门峡渭河库区洪灾损失中的直接损失部分,分别确定泛区载物单项损失系数和渭河库区的综合损失系数后定量计算出渭河库区洪灾直接经济损失。 相似文献
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介绍了调峰运行的汽轮机转子热应力的计算方法。为了减少启动时间和提高汽轮机的安全性,拟定了热定应力控制曲线及保护曲线,设定应力保护。对转子的寿命损耗进行了分析。 相似文献
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The lifetime of molten carbonate fuel cells is simulated in terms of electrolyte loss rate, voltage reduction rate, and activation energy using 7 cm2 coin- and 100 cm2 bench-type molten carbonate fuel cells. Arrhenius plots are used to determine the temperature dependence of the anode gas-phase mass transfer resistance, cathode gas and liquid-phase mass transfer resistances and electrolyte loss rate. The gas-phase mass transfer resistance of the anode has positive activation energy, indicating more substantial resistance at higher temperatures. The cathodic gas-phase mass transfer resistance has small and negative activation energy. In contrast, the cathode shows negative and positive activation energies at the mass transfer resistance of superoxide ion ( and CO2 in the liquid electrolytes, respectively. The negative value indicates a lower overpotential at higher temperatures and vice versa. The Arrhenius plot of the electrolyte weight loss rate shows positive activation energy, indicating that an increase in temperature causes a simultaneous increase in electrolyte weight loss. The cell life of a molten carbonate fuel cell is predicted using a factor that relates the voltage reduction and electrolyte loss rates. A lower value of the factor gives a longer cell life. 相似文献