采用四象限探测器和功率谱密度法，搭建了一套快速标定光镊三维光阱刚度的测量系统.实验中，用四象限探测器记录微粒做受限布朗运动时的位置信息，用功率谱密度法标定光阱刚度，测得了直径0.97 μm SiO2小球和直径1 μm PMMA小球的光阱刚度与激光功率的关系.结果表明：对于SiO2小球，当激光功率为50~120 mW时，光阱刚度与激光功率成正比；对于PMMA小球，当激光功率为80~130 mW时，光阱刚度与激光功率成正比.该光镊系统可用于生物、物理等微观领域研究的高准确度测力系统.

The approaches to obtaining desired intensity or phase modulation by twisted-nematic liquid crystal display (TN-LCD) have been extensively studied based on the knowledge of the LCD's internal structure parameters. Generally, the TN-LCD placed between two linear polarizers (P) produces coupled intensity and phase modulation. To obtain the commonly used phase-only modulation, quarter wave plates (QWPs) are often used in front of and/or behind the LCD. Here we present a method to optimize the optical modulation properties of the TN-LCD to obtain phase-only modulation in the configuration of P-QWP-LCD-QWP-P each with proper orientation. Our method is based on the macroscopical Jones matrix descriptions for the LCD, the QWPs, and the linear polarizers. Through Jones matrix calculations, the orientations of the polarizers and QWPs can be optimized to satisfy differently desired modulation demands. In contrast to the traditional method, which requires knowledge of the LCD's internal structure parameters, our method simplified the complicated theory analysis and can work in the absence of information on the LCD's internal structure parameters, which are usually not available for the commercial products.

根据实时数据库,内存数据库的基本理论,提出了将内存数据库思想溶于传统磁盘数据库中的内存数据访问技术.通过对应用程序与数据库系统之间接口的重新封装,实现了此技术在数据访问对象(DAO)中的应用,使数据库检索、存取等过程能在有限的内存中进行,避免了大量磁盘数据的I/O,提高了应用系统的执行效率.