偏振光学编码及解码研究

提出了用 Li Nb O3晶体制作的光耦合双泡克耳斯楔编码器的设计方法 ,分析了在远场空间的偏振编码原理 ,并对其用琼斯矩阵法作了解码分析     

分段自相关动态光散射法测量亚微米粒度

介绍了动态光散射法测量微粒尺度的原理，通过对相关函数相对的分析，提出了分段自相关的方法，该方法解决了高速，大数据量采集的困难，又不显著影响相关函数的精度，给出了实验装置及实验结果，测量结果与标准样品的标称值相符。     

基于感兴趣区域的海洋卫星遥感图像压缩算法

针对海洋监视卫星遥感图像的特点,提出了一种基于感兴趣区域的自适应遥感图像近无损压缩算法。该算法利用红-黑小波提升方法检测出目标的边缘,采用阈值法将目标和背景分割,使用外接矩形来描述目标,从而自动确定感兴趣区域。感兴趣区域采用Rice无损熵编码方法,背景区域采用比特平面编码的有损压缩方法。实验结果表明,该算法能有效地划分感兴趣区域,其压缩比较无损压缩有了很大提高,目标无失真,整幅图像的峰值信噪比都在40dB以上。算法的计算复杂度较低,易于硬件实现,而且还具有自适应性和数据包独立的优点,适合于海洋监视卫星遥感图像近无损压缩应用。     

Performance enhancement using the bipolar capacity of bipolar coded fiber Bragg gratings and balanced detection in the spectral encoded code-division-multiple-access systems

This paper proposes a performance-enhanced code-division-multiple-access (CDMA) system using modified pseudorandom noise (PN) coded fiber Bragg gratings (FBGs) with a bipolar optical CDMA encoder/decoder. The data were encoded either by a unipolar signature sequence of modified PN code or by its complement, depending on whether the data bit was ‘1’ or ‘0’. Numerical simulation confirmed that bit error rate (BER) performance largely improved due to the increased decision margin at the receiver. Furthermore, at the BER of 10⁻⁹, the tolerance of spectral power distortion in the optical source appeared to be nearly twice that of conventional optical CDMA systems.     

定态双向环形气体激光中的饱和效应

从理论上分析了双向环形气体激光中的全饱和效应，导出了定态激光强度分布函数的解析形式，算出了定态双模强度的自相关和相相关函数。与激光的三次模型 实验测相比较，激光的全饱和模型与实验测量符合更，而三次模型的结果偏差较大。     

Micro-optical Characterization of Fluidic Self-assembly of Drosophila Embryos through Surface Tension: Principle, Simulation and Experiments

We describe high precision experimental and numerical characterization of the positioning forces acting on Drosophila embryos that have self-assembled onto two-dimensional arrays of hydrophobic sites on a silicon substrate in water. The forces measured using a surface micromachined optical-encoder force sensor operating in reflection, are in good agreement with numerical simulations based on an extended surface energy model for the oil-based fluidic system. The positioning forces of ellipsoidal embryos on flat pads show a linear-spring-like relationship between the force and displacement on rectangular as well as cross-shaped pads. In contrast, the positioning forces of flat silicon chips, similar in size to the embryos, are linear in the displacement only over a limited range, and are then constant up to the detachment force. The optical force characterization method and the associated surface energy model for the self-assembly process can potentially be used for design optimization of fluidic self-assembly for a wide range of applications in biology.     

Structured mesh generation with smoothness controls

In geometrically complex domains, the Ryskin and Leal (RL) orthogonal mesh generation system may cause mesh distortion and overlapping problems when using the ‘weak constraint’ method with specified boundary point distribution for all boundaries. To resolve these problems, an improved RL system with automatic smoothness control is proposed. In this improved RL system, the automatic smoothness control mechanism is based on five types of smoothness conditions and includes the self‐adjustment mechanism and the auto‐evaluation mechanism for an empirical parameter. The proposed system is illustrated using several test examples. Several applications to natural domains are also demonstrated. It is shown that the improved RL system is capable of resolving the above problems at little cost of orthogonality. Copyright © 2006 John Wiley & Sons, Ltd.     

Auto‐Tandem Catalysis: A Single Catalyst Activating Mechanistically Distinct Reactions in a Single Reactor

Domino reactions have received great attention as efficient synthetic methodologies for the construction of structurally complex molecules from simple materials in a single operation. Catalysts in domino reactions have also been well studied. In these reactions, a catalyst activates the substrate(s) only once, and the structure of the product is delineated at that time. Recently, the new concept of “tandem catalysis” in domino reactions, in which catalyst(s) sequentially activate more than two mechanistically distinct reactions, has been proposed. Tandem catalysis is categorized into three subclasses: orthogonal‐, auto‐, and assisted‐tandem catalyses. Auto‐tandem catalysis is defined as a process in which one catalyst promotes more than two fundamentally different reactions in a single reactor. An overview of recent and significant achievements in auto‐tandem catalysis is presented in this paper.     

旋转激光扫描共焦荧光检测式毛细管阵列电泳

研制了一种新型毛细管阵列电泳仪——旋转激光扫描共焦荧光检测式毛细管阵列电泳。采用圆形毛细管阵列,激光扫描共聚焦荧光检测方式,利用了高速直流电机旋转反射镜来进行激光扫描,并且加快了采样速率;采用旋转编码器获得毛细管的绝对位置并对数据采集系统触发来采集信号,并利用研制的8通道毛细管阵列电泳对酪氨酸、赖氨酸、谷氨酸及天冬氨酸的混合物进行了分离分析,获得了良好的分离效果。     

脉冲激光测距机检定测试设备

介绍一种有方便校准测距机主要性能参数的智能化综合检定测试系统。主要检测测距机理的距离准确性、最大及最小测程、脉冲能量、脉宽、重频特性、束散角及光轴稳定性等。给出主要的校准及传递方法。