惯性往复振动设备的机电耦合模型和瞬态过程分析

采用建立离散系统动力学方程的矩阵法,建立了双旋转偏重激振的惯性往复振动设备的动力学方程,该动力学方程与两驱动电机的状态方程一起构成了惯性往复振动设备机电耦合的数学模型．通过分别对不同阻尼、不同电机功率时数学模型的数值仿真和对仿真结果分析,揭示了惯性振动设备瞬态过程的实质,提出了减小振动体瞬态振幅和缩短瞬态过程的新方法．为该类设备瞬态过程的智能控制和工程设计提供了可靠的数学模型．     

Extragradient Methods for Pseudomonotone Variational Inequalities

We consider and analyze some new extragradient-type methods for solving variational inequalities. The modified methods converge for a pseudomonotone operator, which is a much weaker condition than monotonicity. These new iterative methods include the projection, extragradient, and proximal methods as special cases. Our proof of convergence is very simple as compared with other methods.     

空天飞行器SINS/CNS深组合导航算法(英文)

空天飞行器往返于大气层内外,持续工作时间长。捷联惯性/天文组合导航自主性强、隐蔽性好,是最适合空天飞行器的导航方式之一。为提高传统天文定位的导航精度和可靠性,解决其在机载应用中水平基准制约的问题,分析了平台误差角和位置误差对高度角量测的影响,提出了一种以天体高度角为量测信息的捷联惯性/天文深组合导航算法。该算法采用卡尔曼滤波器进行最优估计,可有效估计并补偿系统的姿态误差,减少天文导航定位对水平基准的依赖。仿真表明,单星观测条件下,导航系统姿态误差快速收敛,定位的均方根误差在200 m以内,且系统导航性能随导航星数量的增加而提高。     

非线性惯性力通过密频内共振导致的响应饱和现象

考察一种典型的非线性惯性力通过密频内共振导致的响应饱和现象，简明地揭示了响应饱和现象的一系列典型特点，特别是指出了响应饱和有关的上阈值就是饱和响应通过Ｈｏｐｆ分叉而失稳的激励幅值     

啁啾脉冲堆积用于光脉冲整形

报道了一种利用100 ps啁啾脉冲堆积产生2．2 ns任意整形脉冲的脉冲整形系统。采用掺Yb~(3 )光纤锁模振荡器得到稳定的锁模光脉冲序列,将该锁模脉冲通过啁啾光纤光栅展宽并通过1 nm带宽的高斯形光谱滤波器滤波,得到标准的100 ps高斯形啁啾脉冲序列,将此脉冲选单经过光纤延迟线组成的32路脉冲堆积器,得到了精度为32 bit的重复频率为1 Hz的2．2 ns任意整形光脉冲。研究了堆积脉冲的特性,分析了宽带啁啾堆积整形脉冲的光谱时间扫描特性对激光驱动惯性约束聚变打靶束匀滑的优化作用。实验测得了该系统输出的2．2 ns整形光脉冲具有小于50 ps的上升沿,与100 ps啁啾脉冲的时间抖动小于4 ps。     

基于激光多普勒测速仪的车载组合导航

 针对车载纯捷联惯性导航系统(SINS)导航精度随时间增长而降低的不足,提出了基于激光多普勒测速仪（LDV）这一新型速度传感器的组合导航方案。通过建立SINS/LDV组合导航系统的状态方程和量测方程,设计了系统的卡尔曼滤波器,并对组合导航系统进行了仿真模拟。结果表明：SINS/LDV组合方案能够有效减小SINS导航参数随时间的累积误差,可以实现全自主、高精度导航;当LDV测速精度为0.1%时,组合导航系统的位置精度提高了2个数量级,速度精度提高了1个数量级。     

X射线相衬成像中靶丸球壳界面晕区暗区现象

在微聚焦X射线以及等离子体X射线源平台上开展了多层球壳靶丸的相衬成像实验。实验结果表明,通过相衬成像能够获得清晰的多层球壳靶丸图像并观察到球壳内外表面晕区暗区现象。根据光的折射原理解释了该晕区暗区现象产生的物理机制。实验结果与几何模型计算结果符合较好。     

The extragradient algorithm with inertial effects for solving the variational inequality

In this article, we introduce an algorithms by incorporating inertial terms in the extragradient algorithm. A weak convergence theorem is established for the proposed algorithm. Numerical experiments show that the inertial algorithms speed up the original ones.     

广义Kuramoto—Sivashinsky方程吸引子的分形结构

首先给出广义Ｋｕｒａｍｏｔｏ＿Ｓｉｖａｓｈｉｎｓｋｙ（ＧＫＳ）方程周期初边值问题在Ｈ２空间惯性集的构造，进而给出并证明ＧＫＳ方程吸引子的分形结构，同时发现吸引子的一个分形局部化指数型逼近序列·上述结果精细和推进了［１，３，５，７］关于惯性集和吸引子的结论，刻划了吸引子的一种几何结构     

Effects of Molecular Weight on Thermal Degradation of Poly(α-methyl styrene) in Nitrogen

The effects of molecular weight on the thermal degradation behavior of poly(α-methyl styrene) (PAMS) was investigated by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) and thermogravimetric analysis (TGA). The Py-GC/MS analysis results showed that the degradation of PAMS with different molecular weights in nitrogen produced only the monomer, alpha-methylstyrene. The TGA results showed a pronounced reduction in the decomposition temperature with increasing molecular weight. The degradation kinetic parameters, calculated by the Kissinger and the Coats–Redfern methods, further revealed that the activation energy and the pre-exponential factor decreased with increasing molecular weight. Most importantly, the degradation order of the PAMS in nitrogen remained around 1, independent of the molecular weight, suggesting the maintenance of the depolymerization mechanism. All the above results provided an insight into the effects of molecular weight on the thermal degradation behavior of PAMS.