蛋白质结构预测的拟物拟人算法研究

根据国际上最新提出的蛋白质结构预测问题的三维欧氏空间连续模型,找到了相应的物理模型,并且设计了适当的拟人策略,形成了相应的拟物拟人算法。

盘鼓混合式转子建模与动力学特性

首先,针对大型旋转机械中混合式转子的转盘、鼓筒组合旋转构件抗弯曲的高刚性特点,将盘鼓混合旋转构件近似为刚性圆柱体,并建立厚转盘转子系统动力学模型;其次,考虑转轴弯曲特性和所储弹性势能,以曲线拟合结合Hermite插值法计算转轴弯曲刚度.对比传统Jeffcott转子系统进行数值算例的分析结果表明,转盘厚度是影响转子系统动力学固有特性的主要因素之一.

热致混合式转子变结构与动力学特性

航空发动机、汽轮机等大型旋转机械多运行在复杂多变的高温环境中,机组主转子系统在工况下因热膨胀而产生结构变化,进而影响运行特性。首先,考虑盘鼓混合式旋转构件与转轴相比具有高刚度特点,将其结构简化并建立单厚盘转子动力学模型;其次,针对热膨胀引发的系统变结构特征,以曲线拟合结合Hermite插值法描绘出圆柱厚盘窜动到任意位置时的转轴弯曲情况,根据弯曲轴所储存的弹性势能运用数值方法折算出对转盘所提供的恢复力及转轴的弯曲恢复刚度;最后,通过数值分析热膨胀诱发的轴向窜动对厚盘转子系统进动频率、临界角速度和振动响应幅值等动力学特性的影响,验证了热膨胀诱发的转轴窜动因素是影响厚盘转子系统动力学特性的主要因素之一。

The Buckling Behavior of Boron Nitride Nanotubes under Bending： An Atomistic Study

In this paper, the buckling behavior of zigzag BN （Boron Nitride） nanotubes under bending is studied through molecular dynamics finite element method with Tersoff potential. The tube with namely （15, 0） BN zigzag tube is investigated. The critical bending buckling angle, moment and curvature are studied and examined with respect to the tube length-diameter ratios from 5 to 30. Effects of a SW （Stone-Wales） defect in the middle tube on the bending behavior are also discussed. The results show that the tube length affects significantly the bending behavior of these tubes. All tubes exhibit brittle fracture under bending. The buckling takes place at the middle in the compressive side of these tubes. These results are important information on the buckling behaviors of pristine and Stone-Wales BN nanotubes, which will be useful for their future applications.