In order to compare the workability of AZ110 alloy with and without addition of La-rich Mish Metal(MM), hot compression tests were performed on a Gleeble-3500 D thermo-mechanical simulator at the deformation temperatu...In order to compare the workability of AZ110 alloy with and without addition of La-rich Mish Metal(MM), hot compression tests were performed on a Gleeble-3500 D thermo-mechanical simulator at the deformation temperature range of 473-623 K and strain rate range of 0.001-1 s-1. The flow stress, constitutive relation, DRX kinetic model, processing map and microstructure characterization of the alloys were investigated. The results show that the flow stress is very sensitive to deformation temperature and strain rate, and the peak stress of AZ110 LC(LC = La-rich MM) alloy is higher than that of AZ110 alloy.The hot deformation behavior of the alloys can be accurately predicted by the constitutive relations. The derived constitutive equations show that the calculated activation energy Q and stress exponent n for AZ110 alloy are higher than the calculated values of AZ110 LC alloy. The analysis of DRX kinetic models show that the development of DRX in AZ110 LC alloy is earlier than AZ110 alloy at the same deformation condition. The processing maps show that the workability of AZ110 LC alloy is significantly more excellent than AZ110 alloy and the microstructures are in good agreement with the calculated results.The AZ110 LC alloys can obtain complete DRX microstructure at high strain rate due to its higher stored energy and weak basal texture.展开更多
The influence of Ce-rich mish metal（MM） and electromagnetic stirring（EMS） on microstructure evolution of AZ91D magnesium alloy was investigated by optical microscopy, scanning electron microscopy（SEM）, energy di...The influence of Ce-rich mish metal（MM） and electromagnetic stirring（EMS） on microstructure evolution of AZ91D magnesium alloy was investigated by optical microscopy, scanning electron microscopy（SEM）, energy dispersion spectrum（EDS） and X-ray diffraction（XRD）. The microstructure of AZ91D and alloying AZ91D is different. Except dominant primary α（Mg） and β-Mg 17Al 12 in AZ91D, a new phase Al 11MM3 is observed in alloyed AZ91D. Increasing Ce-rich MM, primary α grains can be refined, the content and grain size of β obviously decrease, furthermore, its morphology degrades from discontinuous network to separated particles, and Al 11MM3 amount substantially increases and acicular Al 11MM3 aggregates into clusters at grain boundaries. In EMS process, α morphology evolves from rosette to sphere, and then spherical-like with the decrease of isothermal stirring temperature. Moreover, Al 11MM3 mainly distributes inside primary grains and eutecticum in form of short-rod. EMS can alter not only the primary morphology but Al 11MM3.展开更多
Death is one of the urgent crises event in human society that occur during the lifecycle of each individual. It has anintegral relation with religion, especially with rites and rituals, through which the deceased pers...Death is one of the urgent crises event in human society that occur during the lifecycle of each individual. It has anintegral relation with religion, especially with rites and rituals, through which the deceased person is appeased withthe intervention of supernatural. FurtherInore, the death rites, popularly known as funeral rites, which incorporatethe deceased into the world of the dead are more extensively elaborated and assigned the greatest importance.Mourning is integral element related with the death and during the event social life is suspended for all thoseaffected by it and length of the period increases with the closeness of social ties with the deceased. In every society,there are certain customs related to death, as well as disposal of the corpse which reflect the parochial belief systemassociated with the event. In this paper, an attempt has been made to evaluate the customs associated with disposalof the death, integral parochial religious rites and rituals among the Mishings of Upper Assam, India.展开更多
为了实现轮毂焊缝缺陷的智能化检测,本文对深度学习目标检测算法(You Only Look Once version3,YOLOv3)进行改进,得到YOLOv3-MC算法用于轮毂焊缝缺陷的检测。首先,使用工业相机采集轮毂焊缝图像,然后标注图像制作数据集,并且通过数据增...为了实现轮毂焊缝缺陷的智能化检测,本文对深度学习目标检测算法(You Only Look Once version3,YOLOv3)进行改进,得到YOLOv3-MC算法用于轮毂焊缝缺陷的检测。首先,使用工业相机采集轮毂焊缝图像,然后标注图像制作数据集,并且通过数据增强方法扩充数据集。接着,为了提高算法检测精度,使用Mish激活函数替换YOLOv3主干网络中的激活函数。修改算法的损失函数,使用完备交并比(Complete Intersection over Union,CIoU)的计算方法提升算法检测的定位精度。最后使用训练集训练算法模型,再使用验证集和测试集图像数据进行检测试验,结果表明,YOLOv3-MC的最优模型在验证集上的平均准确率(Mean Average Precision,mAP)达到了98.94%,F1得分值为0.99,平均交并比(Average Intersection over Union,AvgIoU)为80.92%,检测速度为76.59帧/秒,模型大小234MB。该模型在测试集上的检测正确率达到了99.29%。相较于传统机器视觉检测方法,该方法提高了检测精度,满足轮毂生产企业的焊缝实时在线检测需求。展开更多
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0301104)the National Natural Science Foundation of China(No.51771043)support by State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization。
文摘In order to compare the workability of AZ110 alloy with and without addition of La-rich Mish Metal(MM), hot compression tests were performed on a Gleeble-3500 D thermo-mechanical simulator at the deformation temperature range of 473-623 K and strain rate range of 0.001-1 s-1. The flow stress, constitutive relation, DRX kinetic model, processing map and microstructure characterization of the alloys were investigated. The results show that the flow stress is very sensitive to deformation temperature and strain rate, and the peak stress of AZ110 LC(LC = La-rich MM) alloy is higher than that of AZ110 alloy.The hot deformation behavior of the alloys can be accurately predicted by the constitutive relations. The derived constitutive equations show that the calculated activation energy Q and stress exponent n for AZ110 alloy are higher than the calculated values of AZ110 LC alloy. The analysis of DRX kinetic models show that the development of DRX in AZ110 LC alloy is earlier than AZ110 alloy at the same deformation condition. The processing maps show that the workability of AZ110 LC alloy is significantly more excellent than AZ110 alloy and the microstructures are in good agreement with the calculated results.The AZ110 LC alloys can obtain complete DRX microstructure at high strain rate due to its higher stored energy and weak basal texture.
文摘The influence of Ce-rich mish metal（MM） and electromagnetic stirring（EMS） on microstructure evolution of AZ91D magnesium alloy was investigated by optical microscopy, scanning electron microscopy（SEM）, energy dispersion spectrum（EDS） and X-ray diffraction（XRD）. The microstructure of AZ91D and alloying AZ91D is different. Except dominant primary α（Mg） and β-Mg 17Al 12 in AZ91D, a new phase Al 11MM3 is observed in alloyed AZ91D. Increasing Ce-rich MM, primary α grains can be refined, the content and grain size of β obviously decrease, furthermore, its morphology degrades from discontinuous network to separated particles, and Al 11MM3 amount substantially increases and acicular Al 11MM3 aggregates into clusters at grain boundaries. In EMS process, α morphology evolves from rosette to sphere, and then spherical-like with the decrease of isothermal stirring temperature. Moreover, Al 11MM3 mainly distributes inside primary grains and eutecticum in form of short-rod. EMS can alter not only the primary morphology but Al 11MM3.
文摘Death is one of the urgent crises event in human society that occur during the lifecycle of each individual. It has anintegral relation with religion, especially with rites and rituals, through which the deceased person is appeased withthe intervention of supernatural. FurtherInore, the death rites, popularly known as funeral rites, which incorporatethe deceased into the world of the dead are more extensively elaborated and assigned the greatest importance.Mourning is integral element related with the death and during the event social life is suspended for all thoseaffected by it and length of the period increases with the closeness of social ties with the deceased. In every society,there are certain customs related to death, as well as disposal of the corpse which reflect the parochial belief systemassociated with the event. In this paper, an attempt has been made to evaluate the customs associated with disposalof the death, integral parochial religious rites and rituals among the Mishings of Upper Assam, India.
文摘为了实现轮毂焊缝缺陷的智能化检测,本文对深度学习目标检测算法(You Only Look Once version3,YOLOv3)进行改进,得到YOLOv3-MC算法用于轮毂焊缝缺陷的检测。首先,使用工业相机采集轮毂焊缝图像,然后标注图像制作数据集,并且通过数据增强方法扩充数据集。接着,为了提高算法检测精度,使用Mish激活函数替换YOLOv3主干网络中的激活函数。修改算法的损失函数,使用完备交并比(Complete Intersection over Union,CIoU)的计算方法提升算法检测的定位精度。最后使用训练集训练算法模型,再使用验证集和测试集图像数据进行检测试验,结果表明,YOLOv3-MC的最优模型在验证集上的平均准确率(Mean Average Precision,mAP)达到了98.94%,F1得分值为0.99,平均交并比(Average Intersection over Union,AvgIoU)为80.92%,检测速度为76.59帧/秒,模型大小234MB。该模型在测试集上的检测正确率达到了99.29%。相较于传统机器视觉检测方法,该方法提高了检测精度,满足轮毂生产企业的焊缝实时在线检测需求。
