基于磁扰动状态下Q235钢应力梯度的无损表征

基于电磁学原理的铁磁性材料应力无损检测,在工程实际中具有广阔的应用前景.本文根据对增量磁导率概念新的理解,提出了一种铁磁性材料在低频交变强磁场周期磁化状态下的高频交变弱磁场扰动磁化作用方式.通过提取一个强磁场磁化周期内的平均增量磁导率,对四点弯曲装置加载Q235钢所产生的纯弯曲状态下的应力梯度及沿着深度分布的磁弹性能总量进行了磁学无损表征.通过两组不同实验参数设置下的平行实验,验证了所提出的测试方法可以有效地检测加载条件下试件内部应力梯度及沿着深度分布的磁弹性能总量.两组实验结果均具有一般性,表明该检测方法具有可行性,并且具有一定的工程实际应用价值.     

纯钛板成形极限曲线的预测（英文）

商业纯钛(CP Ti)由于其轻质,高比强度和优异的耐腐蚀性能而被广泛应用于板式换热器。然而,与汽车用钢和铝合金相比,关于CP Ti板的塑性变形特征和压制成形性的研究相对较少。本文研究与CP Ti板压制成形相关的应力-应变关系及其力学性能和硬化行为。结果表明,CP Ti板的真应力-真应变关系曲线符合Kim-Tuan硬化方程,而不是Voce和Swift模型。通过冲压试验验证CP Ti板的成形极限曲线(FLC)可作为压制成形性的标准,并可通过Hora改进的最大力准则来分析预测。通过Kim-Tuan硬化模型和合适的屈服函数预测的FLC与冲压试验的结果吻合良好。     

Design concept development of a variable magnetization motorwith improved efficiency and controllable stiffness for roboticapplications

A variable magnetization(VM) motor by incorporating magnets that can be flexibly configured with variable magnetization process is proposed to meet the emerging requirements on motor efficiency and actuator compliance in robotic applications. A generalized spin torque model is established which provides a relationship between the motor torque and two different types of motor inputs, the current inputs and the magnet magnetizations. Avariable magnetization process is proposed based on the study of the hysteresis properties of the magnetic materials and the design criteria for implementing the variable magnetization process with current pulses are established. The feasibility of the variable magnetization is validated with experimental data and the motor functions and performances are numerically demonstrated and evaluated. The results show that the VM motor can maintain high efficiency by switching between two actuation modes. Controllable stiffness at different equilibria can be also achieved with the VM motor with instantaneous magnetizing current pulses.     

Microenvironmental regulation of stem cells injected in the area at risk of neurodegenerative diseases

The complex mechanism of degenerative diseases and the non-specific modulation of regenerative targets aretopics that need to be elucidated in order to advance the use of stem cells in improvement of neurodegenerative diseases.From pre-transplantation through post-transplantation, there are many changes in the conditions, both inside andoutside of the stem cells that have not been carefully considered. This has hindered development in the field of celltherapy and regeneration. This viewpoint highlights the potential implications of intracellular and extracellularalterations of stem cells in transplanted areas at risk of neurodegenerative disease.