带可变反射率镜无源和有源腔的衍射分析

借助于快速傅里叶变换（ＦＦＴ）法求解光腔衍射积分，在三维情况下，对带可变反射率镜（ＶＲＭ）矩形截面无源和有源平行平面的模式结构进行数值解，对计算结果作了比较和分析，结果表明，腔膜结构与介质增益特性和包括ＶＲＭ在内的光腔参数有关。     

有限形变和粘弹性阻尼对纵向应变孤波的影响

本文用微扰理论方法,详细地研究了非线性弹性杆中纵向应变孤波在有限形变和线性粘弹性阻尼作用下的演变规律.发现有限形变和线性粘弹性阻尼对纵向应变孤波的主要影响是:a.孤波发生形变;b.孤波的传播速度减小;C.孤波的能量发生耗散;d.孤波后面会生长出一条振荡形状的小尾迹.当忽略有限形变和线性粘弹性阻尼时,应变孤波的能量是一个常数,这种能量的聚集可能导致杆的非线性结构断裂.     

非比例可变阻尼结构频响函数的二次摄动分析

通过用复模态分析得来的频率响应函数矩阵,分析了可变阻尼参数对频响函数的灵敏度,从而得出响应功率谱及其响应加速度对阻尼参数的变化率,并将此理论应用到汽车减振阻尼参数优化控制中。     

叶根阻尼对叶片振动的影响

本文用有限单元法,对两种模型叶片,计算了叶根阻尼对叶片共振振幅的影响,以及叶根弹性和接触情况对叶片固有频率的影响。本文把叶根和轮缘之间的振动滑移看成是动力接触问题,将静力问题中的接触条件推广到动力问题,并提出了解法。本文用平面应变单元和平板单元对整个叶片进行离散,并导出了用于连接平面单元和梁(平板)单元的过渡单元的位移模式和座标变换式。本文还根据模态综合法的基本思想,提出了一种缩减自由度的方法,得到了比较满意的结果。最后进行了实验验征。     

Long-term memory was impaired in one-trial passive avoidance task of day-old chicks hatching from hypomagnetic field space

The retained curve in one-trial passive avoidance task (OTPAT) of day-old chicks hatching from natural geomagnetic field (control groups) is consistent with the acknowiedged three-phase model. The two dips are at the 20th min and the 60 rain, and the avoidance rates (AR) to the red bead in short- and intermediate-term memory are 68.4% on average, while that in the long-term momory was 74.8%. The OTPAT retained curve of day-old chicks hatching from hypomagnetic field space (experimental groups) presents the marked timing effect. The two dips were at the 25th min and the 50th min, the avoidance rates to the red bead (ARt) in the short- and intermediate-term memory was 74.1% on an average, which was resembled to that in control group;however, the long-term memory appeared an obvious fluctuation. Compared with that in control groups, ARt and the deviation coefficient in experimental groups were decreased by 25.3% and increased by 1.3 times, respectively. That is to say, both the memory ability and stability in the experimental chicks declined. The result shows that the hypomagnetic field space has a negative effect on the development of chick brain function, and that cannot be negligible.     

结合理科教学实际开展"研究性学习"

利用一种崭新的类似科学研究的方式,从获取知识,应用知识,解决问题等几方面,屏弃"接受性学习"的弊端,探讨理科教育教学实施"研究性学习"的想法和做法.     

Passive Target Tracking Based on Current Statistical Model

Bearing-only passive tracking is regarded as a nonlinear hard tracking problem. There are still no completely good solutions to this problem until now. Based on current statistical model, the novel solution to this problem utilizing particle filter （PF） and the unscented Kalman filter （UKF） is proposed. The new solution adopts data fusion from two observers to increase the observability of passive tracking. It applies the residual resampling step to reduce the degeneracy of PF and it introduces the Markov Chain Monte Carlo methods （MCMC） to reduce the effect of the “sample impoverish”. Based on current statistical model, the EKF, the UKF and particle filter with various proposal distributions are compared in the passive tracking experiments with two observers. The simulation results demonstrate the good performance of the proposed new filtering methods with the novel techniques.     

Some Remarks on Euler Equations with Damping in Multi-Dimensions

We consider the Cauchy problem of Euler equations with damping. Based on the Green function and energy estimates of solutions, we improve the pointwise estimates and obtain L1 estimate of solutions.     

非能动堆芯应急冷却系统试验分析

在改造后的AC600全压堆芯补水箱实验装置上，实验研究了不同尺寸的冷段破口，不同的堆芯补水箱压力平衡管以及自动卸压系统对非能动堆芯应急冷却系统瞬态特性的影响，描述了实验过程及实验结果。为先进压水堆非能动堆芯应急冷却系统的设计提供了实验依据。     

类椭圆非线性迟滞隔振系统的动力学模型

应用类椭圆函数建立了非线性迟滞隔振系统的动力学模型，并导出了系统动力学模型的实用表达式.该模型由非线性刚度和非线性阻尼构造而成，模型中各个参数具有明确的物理意义，各阶刚度系数能很好地描述系统中存在的线性和非线性特性，而阻尼函数能很好地描述系统的迟滞和耗能特性.模型中含有待辨识的阻尼成分函数，该函数能反映系统中可能存在的高阶阻尼、粘性阻尼和干摩擦阻尼等各种阻尼成分.由于在模型中将阻尼项表示为位移的函数，因而减少了测量工作量，方便了数值计算.应用动力学模型重构了非线性迟滞隔振系统的恢复力-位移回线，结果表明理论回线与实验回线吻合得很好.