四环素类抗菌素碱性降解荧光增敏作用研究

四环素类抗菌素的碱性溶液(kOH)在沸水浴中加热一定时间而发生降解,其降解物的荧光激发光谱和发射光谱均发生改变,且荧光强度较四环素类抗菌素本身的天然荧光增强5~190倍,认为发生了分子内亲核断环反应,生成具有内酯结构的降解物,此降解物内酯结构中氧原子上孤对电子与共轭π电子相互作用.使分子中共轭电子体系的离域性增大,荧光增强.国家自然科学基金;福建省自然科学基金资助项

Mechanism of Surface Formation for Two-dimensional Ultrasonic Vibration Assisted Grinding of Monocrystal Silicon with Vertical Workpiece Vibration

通过单晶硅磨削试验以及单颗金刚石磨粒划擦试验,分析垂直于工件平面的二维椭圆超声振动磨削单晶硅的表面形成机制。椭圆超声振子由压电陶瓷晶体与金属弹性体粘接制成,其伸缩模态和弯曲模态频率相同,当输入具有一定相位差的两个交流电压信号时产生二维椭圆振动。试验结果表明,由于二维椭圆振动的施加改变了单晶硅的材料去除机制,加工表面质量明显提高,表面粗糙度显著降低,磨削沟槽变浅而宽,切屑变厚而短,单晶硅材料延性域去除比例增加;通过改变超声振动振幅与磨削深度之间大小关系,可实现磨削刃对工件的连续性接触去除和断续性接触去除两种模式的转变。The mechanism of surface formation for two-dimensional elliptic ultrasonic vibration assisted grinding with the vertical direction to workpiece is investigated by grinding experiments and single point diamond abrasive scratching experiments on monocrystal silicon.The vibrator is produced by bonding a PZT on a metal elastic body,frequencies of both longitudinal mode and bending mode are nearly the same,and an elliptic motion occurs when two alternating current signals with phase difference are applied to the PZT.The experimental results show that the workpiece surface quality is improved obviously,and the surface roughness is decreased significantly.And moreover,the grinding grooves become much shallower and wider,and the chip is also much thicker and shorter.It is known that the percent of ductile mode removal material increases.In addition,as the relation between vibration amplitude and grinding depth of cut is changed,two kinds of material removal mechanism,continuous contact and interrupting cutting,can be realized.国防科研资助项目(62301090103

Development of a Two-dimensional Ultrasonic Vibration Assisted Grinding Technique of Monocrystal Silicon

基于超声振动磨削能有效提高加工效率及加工表面质量的特性,通过设计具有伸缩和弯曲两种模态的压电陶瓷椭圆振子,实现了单晶硅二维椭圆振动磨削技术。对超声振子的振动特性进行检测,证实改变压电陶瓷两电极之间的交流信号相位差和电压幅值,可得到不同形状和振幅的椭圆振动。对单晶硅进行超声磨削与普通磨削的对比试验,结果表明二维振动磨削的磨削力大幅降低,表面粗糙度显著减小,表面质量明显提高,加工表面延性域去除比例增加。从而证实二维超声振动磨削方法能够实现高效率高质量单晶硅加工。Based on the characteristics of higher machining efficiency and higher surface quality of ultrasonic vibration grinding,a two-dimensional ultrasonic vibration grinding of monocrystal silicon technique is achieved by designing elliptical vibrator with longitudinal mode and bending mode.The measurement results on the vibration characteristics of vibrator show that shape and amplitude of elliptical vibration can be modulated by changing voltage amplitude and phase difference between the piezoelectric ceramics electrodes.The grinding experimental results show that under the elliptic ultrasonic vibration assistance,grinding forces are reduced largely,the surface roughness is decreased significantly,the surface quality is improved obviously,and moreover the percentage of ductile-mode removal material increases.These indicate that high efficiency and high surface quality machining of monocrystal silicon can be achieved with elliptic vibration assisted grinding.国防科研资助项目(62301090103

Design of Master-Slave Operation Robot Based on Impedance Control in Minimally Invasive Spinal Surgery

针对面向脊柱微创手术的机器人系统,提出了适用于双系统的阻抗控制策略,开展了相关的理论分析和实验验证研究.首先通过运动学计算得出末端执行器到关节角的关系,然后通过阻抗关系模型推导得出力与位置之间的转化公式,最后通过位置控制计算每个关节角的实际位置.本文解决了力和位置控制难以协调这一关键问题,提高了脊柱微创手术机器人力和位置控制的精确性,保证了主手和从手之间位置和力的一致性,使得从手的状态在主手得以精准复现.在手术层面上,系统将医生从长期的繁重操作中解救出来,提升了脊柱微创手术的操作精度和最终效果

一种2自由度膝关节用截骨执行器

本实用新型涉及一种2自由度膝关节用截骨执行器，包括Y向移动机构、X向移动机构、六维力传感器和骨切割工具，Y向移动机构设有Y向驱动组件、Y向架体和Y向滑座，且所述Y向滑座与所述Y向架体滑动连接并通过所述Y向驱动组件驱动移动，所述X向移动机构包括X向驱动组件、X向架体和X向滑座，所述X向架体与所述Y向滑座固连，且所述X向滑座与所述X向架体滑动连接并通过所述X向驱动组件驱动移动，所述骨切割工具安装于所述X向滑座上，且所述骨切割工具与所述X向滑座之间设有六维力传感器。本实用新型能够精确控制骨切割工具位移，并且可以获得骨切割工具精准的力及力反馈，从而可以辅助系统完成切骨轨迹在线规划以及切骨轨迹跟踪

基于CPCI总线的高性能容错空间计算机系统设计研究

面向未来空间计算应用,研究了一种基于CPCI总线的HIP-FTSC(高性能容错空间计算机)系统,描述了系统体系结构设计,总结了其中的关键技术及实现途径,最后在该系统上对一种应用算法进行了实例化并分析了实验结果.中国计算机学

磷化铟单晶衬底的缺陷控制和高质量表面制备

分析研究了一些缺陷对InP单晶衬底的影响,包括团状结构位错的产生及其对晶格完整性的影响,坑状微缺陷、晶片抛光损伤和残留杂质的清洗腐蚀等.对这些缺陷的形成原因和抑制途径进行了分析.在此基础上获得了"开盒即用(EPI-READY)"、具有良好晶格完整性、表面无损伤的InP单晶衬底抛光片