Nonadiabatic spin-torque and damping effects on vortex core switching triggered by a single current pulse

Switching the orientation of a vortex core by spin-polarised pulse current introduces a promising concept for the reliable addressing of a single nanodisc element inside dense arrays. In this paper, micromagnetic simulations are employed to study the vortex core switching behaviour excited by a short in-plane Gaussian current pulse. We find that both the switching mechanism and the switching time are not sensitive to changes in the phenomenological parameters of spin-torque nonadiabaticity and Gilbert damping. The switching time, however, strongly depends on the current strength. In addition, we have theoretically predicted the parameter range of current pulses to achieve a single switching event.     

Interlaminar Crack Propagation Analysis of ENF Specimens Based on the Cohesive Zone Model北大核心CSCD

Based on the classical laminated plate theory and the cohesive zone model, a theoretical model for general delamination cracked laminates was established for crack propagation of pure mode Ⅱ ENF specimens. Compared with the conventional beam theory, the proposed model fully considered the softening process of the cohesive zone and introduced the nonlinear behavior of ENF specimens before failure. The predicted failure load is smaller than that under the beam theory and closer to the experimental data in literatures. Compared with the beam theory with only fracture toughness considered, the proposed model can simultaneously analyze the influences of the interface strength, the fracture toughness and the initial interface stiffness on the load-displacement curves in ENF tests. The results show that, the interface strength mainly affects the mechanical behavior of specimens before failure, but has no influence on crack propagation. The fracture toughness is the main parameter affecting crack propagation, and the initial interface stiffness only affects the linear elastic loading stage. The cohesive zone length increases with the fracture toughness and decreases with the interface strength. The effect of the interface strength on the cohesive zone length is more obvious than that of the fracture toughness. When the adhesive zone tip reaches the half length of the specimen, the adhesive zone length will decrease to a certain extent. Copyright ©2022 Applied Mathematics and Mechanics. All rights reserved.     

树萝卜属植物化学成分的研究（Ⅱ）：红花树萝卜化学成分的研究

从云南省西双版纳地区产红花树萝卜中分离得到7种化合物,经光谱分析及衍生物的制备等确定为:熊果-12-烯-2β羟基-28-酸(Ⅰ),6β-羟基熊果酸(Ⅱ),羊齿烯醇(Ⅲ),木栓醇(Ⅳ),β-谷甾醇(Ⅴ),胡萝卜甙(Ⅵ),β-谷甾醇葡萄糖醛酸甙(Ⅶ),其中化合物(Ⅰ)是未见报道的新化合物。     

积分不等式证明技巧解析

基于定积分不等式的证明是高等数学教学中的一个难点的认识,重点解析定积分不等式证明过程中所涉及的知识点,并对不等式证明技巧进行分析与归纳,阐述定积分不等式证明的基本思路和解题技巧．     

透射光栅谱仪衍射成像特性的理论模拟

应用部分相干光衍射理论,研究了透射光栅仪对单位振幅的单色扩展光源和连续谱扩展光源的衍射特性,给出了成像面上挑强分布表达式,并数值模拟了该谱仪对黑体辐射连续谱扩展光源的接收成像。     

光场电离下玻璃微毛细管的X射线谱

利用软X射线大面积透射光栅谱仪,对超短强激光脉冲辐照下玻璃微毛细管靶的软X射线发射特性进行了研究。测得了不同的激光能量下、不同长度（3mm、6mm、9mm)的微毛细管的软X射线发射谱,并观察到随着微毛细管长度的增加,X射线发射强度增强。     

光场电离气体原子体系的剩余电子能量

总结并推导了在考虑激光脉冲包络时超短强激光脉冲光场电离多电子气体原子体系的阈上电离能量的计算公式,消除了以往研究中的唯象假设。发展了产生各阶离化态离子的阈值光强和饱和光强的计算方法。数值模拟表明,随激光能量升高,平均剩余电子能量呈现出类似阶梯型平台的饱和行为。     

GLC(E)的拓扑结构

设E是买Banach空间,GLC(E)是E上可逆连续线性场全体.本文证明GLC(E)是含有两个道路连通分支的‖@‖L(E)无界拓扑群,并且把这两个连通分支用Leray-Schauder度表示出来.     

碘取代硝基偶合催化光度法测定痕量硝基酪氨酸

硝基酪氨酸中的硝基可还原为氨基再重氮化后被碘定量取代 ,利用碘 亚硝酸 亚砷酸体系催化光度法可对取代硝基的碘进行测定。据此建立了碘取代硝基偶合催化光度法测定痕量硝基酪氨酸的新方法。本方法的检出限为 0 0 0 2 μmol·L-1 ,线性范围为 0 0 0 5～ 0 2 5μmol·L-1 。应用该法检测了过亚硝酸根与酪氨酸反应后的产物中硝基酪氨酸的含量 ,获得了满意的结果