视网膜显微手术机器人的约束运动规划及仿真

为了辅助医生完成视网膜显微手术中精细的手术操作,过滤颤抖、提高精度和稳定性,提出一种生成手术机器人空间运动约束的方法——虚拟固定器(VF).首先,通过引入手术环境约束和任务约束,采用加权、线性化的多目标约束条件,根据用户的输入设置目标函数,构造了视网膜显微手术中所需的6个虚拟固定器基元.在此基础上,以远程运动中心虚拟约束(RCM VF)的生成为例,通过约束运动基元的组合,推导了复杂约束运动的实现方法.各约束运动基元算法及复杂约束运动算法的仿真结果表明,手术器械可以按照虚拟固定器的定义实现特定的约束运动.最后,在各手术步骤中引入约束运动基元的基础上,在乒乓球和离体猪眼球上进行了手术操作实验,证明了在该虚拟固定器的引导下,视网膜机器人可以完成高难度的手术操作,验证了所提出算法的合理性和有效性.国家自然科学基金(51175013);;福建省高校青年自然基金青年重点项目(JZ160493

Structural and Dynamics Studies of Spinel LiNi_(0.5)Mn_(1.5)O_4 Cathode Material during Initial Charge/Discharge Processes

以nAOH为沉淀剂,采用共沉淀法制备尖晶石lI nI0.5Mn1.5O4正极材料,使用X-射线衍射(Xrd)、傅里叶转换红外光谱(fTIr)和扫描电镜(SEM)分析材料结构与表面形貌.结果表明,该材料属于空间群的无序尖晶石lI nI0.5Mn1.5O4材料,由八面体粒子团聚成3~6μM的大粒子.恒电流充放电结果显示,材料在0.1C倍率下首周放电比容量为121.5 M AH·g-1,经过150周充放电后,材料比容量无明显衰减,其容量保持率为99%.用PITT和原位Xrd联用技术研究了充放电过程中材料的结构与锂离子扩散系数之间的关系.PITT法测得材料中锂离子的扩散系数为10-10~10-11CM2·S-1.The spinel Li Ni0.5Mn1.5O4 material was synthesized by co-precipitation method with Na OH as a precipitant.The structure and morphology of the as-prepared Li Ni0.5Mn1.5O4 materials were characterized by means of XRD, FTIR and SEM.The results indicated that the material belonged to Fd3軈m space group and consisted of octahedral particles with the sizes of 3 ~ 6 μm.Electrochemical tests showed the first discharge specific capacity of 121.5 m Ah·g-1at 0.1C.After 150 cycles, about 99% of reversible capacity was retained for the Li Ni0.5Mn1.5O4 material.A combining potentiostatic intermittent titration technique(PITT) with in-situ XRD measurement was applied for discussing the relationship between lattice parameter and the diffusion coefficient of lithium ion(DLi+) during the first charging-discharging processes.The DLi+value measured by PITT was in the range of 10-10~ 10-11cm2·s-1.国家自然科学基金项目(No.21273184;No.21321062); 973项目(No.2015CB251102)资

Structural and Dynamic Studies of Spinel LiNi0.5Mn1.5O4Cathode Material during Initial Charge/Discharge Processes

以NaOH为沉淀剂，采用共沉淀法制备尖晶石LiNi0.5Mn1.5O4正极材料，使用X-射线衍射（XRD）、傅里叶转换红外光谱（FTIR）和扫描电镜（SEM）分析材料结构与表面形貌. 结果表明，该材料属于空间群的无序尖晶石LiNi0.5Mn1.5O4材料，由八面体粒子团聚成3 ~ 6 μm的大粒子. 恒电流充放电结果显示，材料在0.1C倍率下首周放电比容量为121.5 mAh·g-1，经过150周充放电后，材料比容量无明显衰减，其容量保持率为99%. 用PITT和原位XRD联用技术研究了充放电过程中材料的结构与锂离子扩散系数之间的关系. PITT法测得材料中锂离子的扩散系数为10-10 ~ 10-11 cm2·s-1.The spinel LiNi0.5Mn1.5O4 material was synthesized by co-precipitation method with NaOH as a precipitant. The structure and morphology of the as-prepared LiNi0.5Mn1.5O4 materials were characterized by means of XRD、FTIR and SEM. The results indicated that the material belonged to space group and consisted of octahedral particles with the sizes of 3 ~ 6 μm. Electrochemical tests showed the first discharge specific capacity of 121.5 mAh·g-1 at 0.1C. After 150 cycles, about 99% of reversible capacity was retained for the LiNi0.5Mn1.5O4 material. A combining potentiostatic intermittent titration technique (PITT) with in-situ XRD measurement was applied for discussing the relationship between lattice parameter and the diffusion coefficient of lithium ion (DLi+) during the first charging-discharging processes. The DLi+ value measured by PITT was in the range of 10-10 ~ 10-11 cm2·s-1国家自然科学基金项目（No. 21273184，No. 21321062）及973项目（No. 2015CB251102）资助作者联系地址：1. 厦门大学化学化工学院化学系，福建 厦门 361005；2. 厦门大学能源研究院，福建 厦门 361005Author's Address: 1. Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, Fujian, China; 2. School of Energy Research, Xiamen University, Xiamen 361005, Fujian, China通讯作者E-mail：[email protected]