Fuzzy Impulsive Control of Permanent Magnet Synchronous Motors

The permanent magnet synchronous motors （PMSMs） may experience chaotic behaviours with systemic parameters falling into a certain area or under certain working conditions, which threaten the secure and stable operation of motor-driven. Hence, it is important to study the methods of controlling or suppressing chaos in PMSMs. In this work, the Takagi-Sugeno （T-S） fuzzy impulsive control model for PMSMs is established via the T-S modelling methodology and impulsive technology. Based on the new model, the control conditions of asymptotieal stability and exponential stability for PMSMs have been derived by the Lyapunov method. Finaily, an illustrated example is also given to show the effectiveness of the obtained results.     

Pulsed EPR spectrometer with injection-locked UCSB free-electron laser

We describe the first free-electron laser (FEL)-based pulsed electron paramagnetic resonance (EPR) system designed to study spin dynamics and structure changes of proteins in aqueous solution with nano-second of time resolution. This novel approach opens up the possibility for high-power sub-THz and THz pulsed EPR spectroscopy.     

Required minimum cavity dispersion in stable,graphene mode-locked,Yb-doped fiber lasers

Optical Review - We have numerically investigated the required minimum cavity dispersion (RMCD) for obtaining stable pulses in net normal dispersion, graphene mode-locked, Yb-doped fiber lasers...     

聚龙一号装置上首次铝套筒Z箍缩X射线背光照相实验

在聚龙一号脉冲功率装置上首次完成了对带正弦扰动铝套筒Z箍缩的X射线背光照相实验。实验采用千焦耳激光器（1053 nm, 1 kJ, 1 ns）驱动固体靶材产生X射线, 然后利用基于球面晶体的单色背光照相技术以及直接点投影背光照相技术, 成功观测到约7.5 MA电流驱动条件下, Z箍缩铝套筒的外边界不稳定性发展情况。该实验验证了在聚龙一号装置上联合千焦耳激光器开展X射线背光照相实验的能力, 为后续精密Z箍缩物理研究奠定了基础。     

新型稀磁半导体Mn掺LiCaP的磁电性质

采用基于密度泛函理论的第一性原理平面波超软赝势方法,对纯LiCaP、Mn掺杂LiCaP、Li过量和不足时Mn掺杂LiCaP体系进行几何结构优化,计算并分析了体系的电子结构、能带结构、态密度等.结果表明:Li1±y(Ca1-xMnx) P(x=0. 125,y=0. 125)体系均表现为100%自旋注入,材料均具有半金属亚铁磁性,半金属性稳定,磁矩较大且主要来源于Mn掺入形成的深能级杂质带. Li过量时材料的导电性得到改善,Li不足时体系的居里温度(Tc)提高,说明LiCaP半导体的磁性和电性可以分别通过Mn的掺入和Li的含量进行调控.     

DPLS和SVM的掺假花椒粉近红外光谱定性鉴别

花椒是我国的八大调味料之一。目前花椒市场掺假现象较为多见,为实现掺假花椒粉的快速定性鉴别,采用了近红外光谱结合化学计量学方法进行了探讨。将麦麸粉、稻糠粉、玉米粉和松香粉以1 Wt/Wt.%的递增梯度分别掺入红花椒粉和青花椒粉中,制备掺假浓度范围为1~54 Wt/Wt.%的掺假花椒粉样品,以掺假花椒粉和纯花椒粉共462份样品依次采集其800~2 500 nm范围的漫反射近红外光谱。采用主成分分析法(PCA)对光谱数据进行分析,前3个主成分累计贡献率达98.72%,做出的得分图表明PCA法对掺假的花椒粉具有较好的区域划分。347份样本作为校正集,以特征谱区2 000~2 200 nm范围的257个采样点的光谱信号作为输入,采用判别偏最小二乘法(DPLS)和支持向量机(SVM)建立定性鉴别模型,经不同光谱预处理,对115份验证集样本进行预测,总体鉴别正确率在97.39%~100%之间,表明该方法是快速定性鉴别掺假花椒粉的一个有效手段。     

Transplanted bone marrow stem cells relocate to infarct penumbra and co-express endogenous proliferative and immature neuronal markers in a mouse model of ischemic cerebral stroke

Background  

Several studies demonstrate that neurogenesis may be induced or activated following vascular insults, which may be important for neuronal regeneration and functional recovery. Understanding the cellular mechanism underlying stroke-associated neurogenesis is of neurobiological as well as neurological/clinical relevance. The present study attempted to explore potential homing and early development of transplanted bone marrow stem cells in mouse forebrain after focal occlusion of the middle cerebral artery, an experimental model of ischemic stroke.