The stoichiometric alloy MlB5.0 and the hypo-stoichiometric alloy MlB4.85 were prepared by twin-roller rapid quenching process, and their structure and electrochemical properties were studied. The results of XRD show ...The stoichiometric alloy MlB5.0 and the hypo-stoichiometric alloy MlB4.85 were prepared by twin-roller rapid quenching process, and their structure and electrochemical properties were studied. The results of XRD show that both of the alloys have a typical single-phase hexagonal CaCus-type structure. The cell volume of the hylpo-stoichiometric alloy M1B4.85 is slightly larger than that of the stoichiometric alloy M1B5.0, although its lattice constant cla is smaller. Under 2 C discharging rate, i.e. 640 mA/g, the M1B4.85 has a discharge capacity of 320 mAh/g, which is higher than that of the M1Bs.o, 312 mAh/g. Nevertheless, the capacities of the M1B4.85 and the M1Bs.o decline 24.7% and 20.2% after 400 cycles, respectively. The relationship of electrochemical performances of the alloys with their structures is discussed.展开更多
脆弱的建筑遗产在面临环境的急剧变化时,很容易遭受不可逆转的破坏。采用数字孪生技术对建筑遗产进行保护本质上是通过对真实世界的镜像模型进行模拟计算,减轻建筑遗产实体的损毁风险。筛选2019-2025年Web of Science核心库的相关研究,...脆弱的建筑遗产在面临环境的急剧变化时,很容易遭受不可逆转的破坏。采用数字孪生技术对建筑遗产进行保护本质上是通过对真实世界的镜像模型进行模拟计算,减轻建筑遗产实体的损毁风险。筛选2019-2025年Web of Science核心库的相关研究,对数字化保护溯源,厘清建筑遗产保护数字孪生应用的概念。总结数字孪生在建筑遗产保护中的三类应用场景、两种应用范式和一个动态的孪生流程,分析当前面临的三大技术难点,进而对数字孪生在建筑遗产调查、模型语义丰富以及文化传播三方面的发展前景提出展望。展开更多
The effect of set-back distance on the thermo-mechanical behavior of the strip during twin roll casting(TRC)of an AZ31 magnesium alloy was modeled using finite element method(FEM).Model validation was done by comparin...The effect of set-back distance on the thermo-mechanical behavior of the strip during twin roll casting(TRC)of an AZ31 magnesium alloy was modeled using finite element method(FEM).Model validation was done by comparing the predicted and measured exit strip surface temperature as well as the secondary dendrite arm spacing(SDAS)through the thickness of the sheet to those measured during experiments.Model results showed as the set-back distance increases,the strip exit temperature decreases and the solidification front moves toward the entry of the roll gap.The cast strip also experiences more plastic deformation and consequently,the normal stress on the strip surface and effective strain at the strip center-line increase.Moreover,higher separating forces were predicted for longer set-back distances.Model predictions showed that changing the set-back distance by varying the final thickness has a more significant effect on the temperature and stress-strain fields than altering the nozzle opening height.展开更多
针对数据中心不间断电源(Uninterruptible Power Supply,UPS)系统运行成本高、运维滞后、能效低的问题,提出一套智能化升级框架,构建基于“感知-分析-决策-执行”闭环逻辑的4层系统架构。通过融合数字孪生建模、流式数据处理与机器学习...针对数据中心不间断电源(Uninterruptible Power Supply,UPS)系统运行成本高、运维滞后、能效低的问题,提出一套智能化升级框架,构建基于“感知-分析-决策-执行”闭环逻辑的4层系统架构。通过融合数字孪生建模、流式数据处理与机器学习推理,实现UPS运行状态的精细感知、健康预测与自适应调控。在平台层部署的扩展卡尔曼滤波与贝叶斯网络模型,可显著提升电池健康状态(State of Health,SOH)估算精度与故障定位能力。实证验证显示,该方案在电源使用效率(Power Usage Effectiveness,PUE)、平均维修时间、能耗及运维成本等关键指标上取得了显著优化,验证了其工程实用性与推广价值。展开更多
基金[This project was supported by the National Natural Science Foundation of China (No. 20373016), the Key Project of In-ternational Science and Technology Cooperation of MOST of China (No. 2005DFA60580), the Key Project of Guangdong Province (No. 2005B50101003), and the Excellent Young Teachers Program of MOE of China.]
文摘The stoichiometric alloy MlB5.0 and the hypo-stoichiometric alloy MlB4.85 were prepared by twin-roller rapid quenching process, and their structure and electrochemical properties were studied. The results of XRD show that both of the alloys have a typical single-phase hexagonal CaCus-type structure. The cell volume of the hylpo-stoichiometric alloy M1B4.85 is slightly larger than that of the stoichiometric alloy M1B5.0, although its lattice constant cla is smaller. Under 2 C discharging rate, i.e. 640 mA/g, the M1B4.85 has a discharge capacity of 320 mAh/g, which is higher than that of the M1Bs.o, 312 mAh/g. Nevertheless, the capacities of the M1B4.85 and the M1Bs.o decline 24.7% and 20.2% after 400 cycles, respectively. The relationship of electrochemical performances of the alloys with their structures is discussed.
文摘脆弱的建筑遗产在面临环境的急剧变化时,很容易遭受不可逆转的破坏。采用数字孪生技术对建筑遗产进行保护本质上是通过对真实世界的镜像模型进行模拟计算,减轻建筑遗产实体的损毁风险。筛选2019-2025年Web of Science核心库的相关研究,对数字化保护溯源,厘清建筑遗产保护数字孪生应用的概念。总结数字孪生在建筑遗产保护中的三类应用场景、两种应用范式和一个动态的孪生流程,分析当前面临的三大技术难点,进而对数字孪生在建筑遗产调查、模型语义丰富以及文化传播三方面的发展前景提出展望。
基金The authors of this work would like to appreciate the NSERC(Natural Sciences and Engineering Research Council of Canada)Magnesium Strategic Research Network(MagNET)for the financial support of this work and the Natural Resources Canada Government Materials Laboratory,CanmetMATERIALS located in Hamilton,Ontario for providing the opportunity to perform the experimental parts of the work.The assistance of Dr.M.Kozdras,Dr.A.Javaid,Dr.E.Essadiqi and Mr.G.Birsan and P.Newcombe(from CanmetMATERIALS)in processing the experimental data is gratefully acknowledged.
文摘The effect of set-back distance on the thermo-mechanical behavior of the strip during twin roll casting(TRC)of an AZ31 magnesium alloy was modeled using finite element method(FEM).Model validation was done by comparing the predicted and measured exit strip surface temperature as well as the secondary dendrite arm spacing(SDAS)through the thickness of the sheet to those measured during experiments.Model results showed as the set-back distance increases,the strip exit temperature decreases and the solidification front moves toward the entry of the roll gap.The cast strip also experiences more plastic deformation and consequently,the normal stress on the strip surface and effective strain at the strip center-line increase.Moreover,higher separating forces were predicted for longer set-back distances.Model predictions showed that changing the set-back distance by varying the final thickness has a more significant effect on the temperature and stress-strain fields than altering the nozzle opening height.
文摘针对数据中心不间断电源(Uninterruptible Power Supply,UPS)系统运行成本高、运维滞后、能效低的问题,提出一套智能化升级框架,构建基于“感知-分析-决策-执行”闭环逻辑的4层系统架构。通过融合数字孪生建模、流式数据处理与机器学习推理,实现UPS运行状态的精细感知、健康预测与自适应调控。在平台层部署的扩展卡尔曼滤波与贝叶斯网络模型,可显著提升电池健康状态(State of Health,SOH)估算精度与故障定位能力。实证验证显示,该方案在电源使用效率(Power Usage Effectiveness,PUE)、平均维修时间、能耗及运维成本等关键指标上取得了显著优化,验证了其工程实用性与推广价值。
