双步相移光栅投影测量轮廓术

双三步相移算法证明可以较大地减少数字光栅投影测量轮廓术的测量误差,基于理论分析与实验验证,针对常用的四步、五步相移算法,提出了相应的双四步、双五步相移算法。通过两次传统相移算法得到两幅主值相位图,直接融合两幅主值相位图即可获得测量所需的相位信息,与已有的针对两幅展开相位进行相位融合方法相比,此方法实现简单且更加有效。相较于双三步相移算法,双四步和双五步相移算法实现简单且能够极大地减少测量误差,仅需通过投影2倍数目传统相移算法所需的投影光栅,且可保持常用三步、四步及五步相移算法固有的优点。     

基于S变换的改进窗口傅里叶三维测量法

讨论了一维S变换在处理条纹图中的应用,推导了S变换表达式,提出一种基于S变换脊的自适应窗口傅里叶三维测量法。利用S变换对于频率的敏感性以及S变换脊思想,求得任意点的瞬时频率。推导了在相位跳变剧烈区域相位二阶导φ″(b)对S变换脊的影响,并求得去除此影响后更为准确的瞬时频率。然后将瞬时频率倒数作为经典窗口傅里叶变换(WFT)的窗口大小,解出条纹图的精确相位。最后对去除相位二阶导影响前后基于S脊的WFT进行对比仿真;实验验证其与传统基于小波脊的WFT在抗噪声、解相位精度上的优势。     

Quantum correlations between two non-interacting atoms under the influence of a thermal environment

By considering a double Jaynes-Cummings model, we investigate the dynamics of quantum correlations, such as the quantum discord and the entanglement, for two atoms in their respective noisy environments, and study the effect of the purity and the cavity temperature on the quantum correlations. The results show that the entanglement suffers sudden death and revival, however the quantum discord can still reveal the quantum correlations between the two atoms in the region where the entanglement is zero. Moreover, when the temperature of each cavity is high the entanglement dies out in a short time, but the quantum discord still survives for quite a long time. It means that the quantum discord is more resistant to environmental disturbance than the entanglement at higher temperatures.     

变系数非线性发展方程的G'/G展开解

用近年来提出的(G'/G)展开法首次尝试了对变系数非线性发展方程的求解, 并以两类变系数非线性KdV方程为例,且成功得到了新的精确解. 实践证明: (G'/G)展开法不仅适用于常系数非线性发展方程, 而且还很好地适用于变系数非线性方程,具有广泛的应用前景.     

海水温度测量传感器链

本文对海水温度探测器进行研究，研制了一种新型的海水温测量传感器链，用以测量浅海中水层薄，温度变化剧烈的不同深度动态变化，能实时显示现场温度，声速剖面，为海洋环境数值预报和灾害性海况遥测提供监视技术，水温环境数据也能用于声呐作用距离预报，拖线列阵布放深度选择，潜艇航行安全保障。     

Magnetic Coupling Induced Self-Assembly at Atomic Level

Developing accurate self-assembly is the key for constructing functional materials from a bottom-up approach.At present, it is mainly hindered by building blocks and driving modes. We design a new self-assembly method based on the magnetic coupling between spin-polarized electrons. First-principles calculations show that spinpolarized electrons from different endohedral metallofullerene(EMF) superatoms can pair each other to ensure a one-dimensional extending morphology. Furthermore, without ligand passivation, the EMF superatoms maintain their electronic structures robustly in self-assembly owing to the core-shell structure and the atomic-like electron arrangement rule. Therefore, it should noted that the magnetic coupling of monomeric electron spin polarization can be an important driving mechanism for high-precision self-assembly. These results represent a new paradigm for self-assembly and offer fresh opportunities for functional material construction at the atomic level.     

CFRP层合板低速冲击响应及损伤特性研究

为了研究碳纤维增强复合材料(Carbon Fiber Reinforced Plastics,CFRP)层合板低速冲击力学性能,开展了铺层顺序为[45_4/–45_4]_(4T)的CFRP层合板落锤低速冲击试验。研究了条形冲锤冲击角度和半球形冲锤直径两个影响因素下的CFRP层合板低速冲击力学响应,同时通过凹坑深度和分层损伤面积研究了层合板低速冲击损伤特性。试验结果表明:当条形冲锤冲击角度与层合板表面纤维方向平行时以及以较小直径的半球形冲锤冲击时,最大中心位移和能量耗散较大,凹坑深度和分层面积也较大;在冲锤直径和冲击角度两个单因素变量下,凹坑深度与分层损伤面积成正相关;直径为10 mm的半球形冲锤冲击层合板时,在凹坑区域存在明显的纤维断裂;14 mm和16 mm半球形冲锤冲击时,损伤虽目视可见,但未见明显纤维断裂。     

Interaction between human telomeric G-quadruplexes characterized by single molecule magnetic tweezers

Human telomeric G-quadruplex plays a crucial role in regulating the genome stability. Despite extensive studies on structures and kinetics of monomeric G-quadruplex, the interaction between G-quadruplexes is still in debate. In this work,we employ magnetic tweezers to investigate the folding and unfolding kinetics of two contiguous G-quadruplexes in 100-mM K~+buffer. The interaction between G-quadruplexes and the consequent effect on the kinetics of G-quadruplex are revealed. The linker sequence between G-quadruplexes is further found to play an important role in the interaction between two G-quadruplexes. Our results provide a high-resolution insight into kinetics of multimeric G-quadruplexes and genome stability.     

90nm互补金属氧化物半导体静态随机存储器局部单粒子闩锁传播效应诱发多位翻转的机理

基于单粒子效应脉冲激光实验装置,开展了90 nm互补金属氧化物半导体静态随机存储器的单粒子翻转和闩锁效应实验,并给出了器件单粒子翻转效应位图.实验发现,器件出现了大量的多位翻转和约20 mA的电源电流脉冲.借助器件仿真工具,揭示了器件发生单粒子多位翻转效应的原因.结果表明,器件局部阵列发生单粒子闩锁效应并传播到多个位单元是诱发多位翻转的主要原因.通过对比分析脉冲激光和器件仿真实验结果,发现P/N阱电势塌陷是导致90 nm互补金属氧化物半导体静态随机存储器出现单粒子闩锁传播效应的内在物理机制.     

Atomic coherence control on the entanglement of two atoms in two-photon processes

Considering two identical two-level atoms interacting with a single-mode thermal field through two-photon processes, this paper studies the atomic coherence control on the entanglement between two two-level atoms, and finds that the entanglement is greatly enhanced due to the initial atomic coherence. The results show that the entanglement can be manipulated by changing the initial parameters of the system, such as the superposition coefficients and the relative phases of the initial atomic coherent state and the mean photon number of the cavity field.