周期间歇卷吸条件下弹流油膜的实验研究

应用光干涉方法对周期间歇卷吸条件下的弹流油膜进行了测量,结果显示了三种不同的局部油膜凹陷。第一种油膜凹陷产生于固体表面周期性的运动和停止,纯滚动的凹陷封油量大于纯滑动的封油量。第二种凹陷产生于启动过程的速度振荡瞬时峰值,该类局部凹陷以卷吸速度通过赫兹接触区。纯滑动条件下,界面滑移作用产生第三种凹陷,该凹陷位于入口附近,与表面速度和运动时间有关。实验中观察到的现象可由油膜的挤压效应,卷吸效应和界面滑移效应进行解释。     

CE5T拓展试验轨道精度分析

针对嫦娥5T服务舱(CE5T)拓展试验中的绕地大椭圆轨道，分析了轨道动力学演化趋势，通过测轨数据类型组合策略分析了统一S频段测量(USB)和甚长基线干涉测量(VLBI)在定轨中的贡献，得到了百米级的精密定轨精度；针对地月第二平动点(L2)绕飞轨道，分析了地心和月心积分的轨道动力学差异，制定了精密定轨的参数求解策略，得到了百米级的精密定轨精度；针对月球交会对接轨道的特点，选取三种不同的重力场模型定轨，比较了三者在轨道预报和数据拟合的差异，并与嫦娥3号(CE3)环月轨道的定轨精度进行比对，验证了不同重力场的适用范围，从计算精度和效率两方面制定了优化的定轨策略。     

Active galactic nuclei imaging programs of the RadioAstron mission

Imaging relativistic jets in active galactic nuclei (AGN) at angular resolution significantly surpassing that of the ground-based VLBI at centimetre wavelengths is one of the key science objectives of the RadioAstron space-VLBI mission. There are three RadioAstron imaging key science programs that target both nearby radio galaxies and blazars, with one of the programs specifically focusing on polarimetry of the jets. The first images from these programs reach angular resolution of a few tens of microarcseconds and reveal unprecedented details about the jet collimation profile, magnetic field configuration, and Kelvin-Helmholtz instabilities along the flow in some of the most studied AGN (3C 84, BL Lac, 3C 273, S5 0836 + 710). Here we give an overview of the goals and strategy of these three ongoing programs, highlight their early results, and discuss the challenges of space-VLBI imaging.     

Residual Stress Measurement for Ion-implanted NiTi Alloy by Using Moiré Interferometry and Hole-drilling Combined Method

Residual stresses in ion-implanted NiTi alloy are measured by a combined method of Moiré interferometry and hole-drilling. Oxygen ions are implanted into the NiTi alloy under a voltage of 30 kV by a dose of 1.0×1017 ions/cm2 for one hour. Subsequently, in order to avoid dimensional error, a hole is drilled exactly in the center of the sample. The distribution of residual stresses around the hole is measured. It is indicated that the method which combines the Moiré interferometry with hole-drilling is able to be used to measure residual stresses produced by ion implantation.     

Coherent matter wave inertial sensors for precision measurements in space

We analyze the advantages of using ultra-cold coherent sources of atoms for matter-wave interferometry in space. We present a proof-of-principle experiment that is based on an analysis of the results previously published in Richard et al. (2003) from which we extract the ratio h/m for ⁸⁷Rb. This measurement shows that a limitation in accuracy arises due to atomic interactions within the Bose–Einstein condensate. Finally we discuss the promising role of coherent-matter-wave sensors, in particular inertial sensors, in future fundamental physics missions in space.     

相位偏移干涉测量中移相误差补偿技术研究

 在相位偏移干涉测量技术中,一阶线性和二阶非线性移相误差是产生相位检测误差的主要因素。在研究移相误差对相位偏移干涉法测量精度影响的基础上,提出五步移相算法一阶线性和二阶非线性移相误差补偿技术。该方法从相位偏移干涉图中拟和出移相过程中存在的移相误差,对五幅算法结果进行误差修正。试验证明移相器存在 10%一阶线性误差和 1 %二阶非线性误差时,五幅算法相位检测误差为 0.12弧度;采用该补偿方法可以将相位测量精度减少到 0.02弧度,相当于采用氦氖激光器的倍程干涉仪中位移测量精度从 6.0 nm提高到 1 nm。     

瞬态空气等离子体场的全息术研究

采用双波长双脉冲激光全息术,对有激波存在下的空气放电现象进行了研究。建立了双波长电弧折射率场方程,推导出冲击波区的压强同折射率之间的关系式,得出电弧场的压强分布.曲线及等离子体区的温度分布和电子、离子、原子、分子等粒子的数密度分布。     

一种新的多通道全息干涉计量术

旋转光楔多重全息术，是利用置于平面参考光波光路上的旋转光楔，调制其传播方向，实现多参考光编码记录获得多重全息图，当用平面波垂直入射再现时，就能从理论上分析出再现像的分布、分离条件及估算的通道数等。这种技术用在全息干涉计量上，就是一种新的多通道全息干涉计量术。本文给出这种新技术在时间平均和双曝全息干涉计量上的应用，并讨论了在单次曝光全息干涉计量（实时法）上的应用。实验结果说明，这种新技术是完全可行的     

干涉SAR中相位图的噪声抑制

探讨干涉合成孔径雷达(INSAR)中干涉相位图的噪声抑制方法.在讨论多视平均法抑制噪声的基础上,提出了极限平均视数的概念,推导了极限平均视数的确定公式.在比较条件邻域平均、模糊中值滤波和模数滤波3种非线性噪声抑制方法的基础上,提出了一种结合多视平均和非线性滤波的干涉相位图噪声抑制实现方法,并用ERS-1/2数据的实际处理结果验证了方法的有效性.      

子孔径拼接测量基本算法与迭代算法的性能比较研究

从原理上对子孔径拼接的基本算法与迭代算法即SASL算法进行了比较分析,提出利用SASL算法中重叠计算子问题的求解方法来确定基本算法中的重叠对应关系,并对两种算法的性能进行了对比研究。结果表明SASL算法对于子孔径的对准误差更不敏感,拼接测量结果更为可靠,且适用于平面、球面和非球面。