基于MATLAB中SIMULINK的准周期弹跳运动的仿真模拟

使用MATLAB/SIMULINK仿真软件建立了刚性小球在谐振桌面上做准周期性弹跳运动的动力学模型,对小球在不同倍频下的准周期运动进行了仿真模拟,并得到了小球运动的相图。结果表明：控制参数的选取对小球的动力学行为有着很大的影响。     

Electrical controllable spin valves in a zigzag silicene nanoribbon ferromagnetic junction

We propose two possible spin valves based on a zigzag silicene nanoribbon(ZSR) ferromagnetic junction. By using the Landauer–B u¨tikker formula, we calculate the spin-resolved conductance spectrum of the system and find that the spin transport is crucially dependent on the band structure of the ZSR tuned by a perpendicular electric field. When the ZSR is in the topological insulator phase under a zero electric field, the low-energy spin transport and its ON and OFF states in the tunneling junction mainly rely on the valley valve effect and the edge state of the energy band, which can be electrically modulated by the Fermi level, the spin–orbit coupling, and the local magnetization. When a nonzero perpendicular electric field is applied, the ZSR is a band insulator with a finite energy gap, the spin switch phenomenon is still preserved in the device and it does not come from the valley valve effect, but from the energy gap opened by the perpendicular electric field. The proposed device might be designed as electrical tunable spin valves to manipulate the spin degree of freedom of electrons in silicene.     

人工神经网络用于化学数据解析的研究(Ⅰ)──逼近规律与过拟合

对多层前传网络的过拟合问题进行了探讨。定义了逼近误差和逼近度作为人工神经网络(ANN)的建模评价指标。通过应用于多元非线性校正的数值模拟和实际药物光度分析数据解析,表明该指标意义明确,便于掌握,且能较好地定量表述ANN逼近规律的程度。     

稠密氦气物态方程研究

用二级氢气炮作为冲击压缩加载工具和多通道瞬态辐射高温计作为主要测量系统,测量了冲击压缩氦气等离子体的光辐亮度历史（初始温度293K,初始压力为1.2MPa）。根据实测记录信号波形的有关特征量,计算得到了氦等离子体的Hugoniot物态方程（含冲击温度）。结果发现：实测Hugoniot物态方程可用Saha方程加Debye-Huckel修正物理模型解释。