We obtained n-type and p-type modified graphene by mixing quantum dots and depositing electron-acceptor molecules on the surface of graphene, respectively. The electrical and optical properties of these two types of s...We obtained n-type and p-type modified graphene by mixing quantum dots and depositing electron-acceptor molecules on the surface of graphene, respectively. The electrical and optical properties of these two types of samples were measured. For n-type modified graphene, the electrons were transferred from quantum dots to graphene. The resistance of these quantum dots in modified n-type graphene is significantly smaller than that of pristine graphene. For p-type graphene, modified by electron-acceptor organic molecules of tetracyanoethylene (TCNE), electrons were transferred from graphene to TCNE molecules. The resistance of this molecular modified p-type graphene is about 10% larger than that of pristine graphene. The charge transfer effect on the optical properties of graphene was investigated with Raman spectra.展开更多
文摘针对绳驱动存在的弹性易滑动、误差易累积等问题,提出了一种"钢丝绳+齿形带"的广义驱动方式,将电动机加齿轮、减速器代表的传统刚性动力传递转化为柔性传递.计算得出了钢丝绳拉力大小;运用摩擦力补偿法分析钢丝绳与绳外软管之间的摩擦因数,得出钢丝绳摩擦力与负载的关系.将同一根钢丝绳与绳套的组合进行不同弯曲度的试验;改变钢丝绳在软管中的长度,并于末端施加负载;在固定板上安装钢丝绳,测量拉力及摩擦力的大小进而确定钢丝绳型号.应用ADAMS对绳驱动关节的钢丝绳进行仿真分析.结果表明:弯曲程度对钢丝绳摩擦力影响可忽略;钢丝绳摩擦力与其长度、负载大小都成正比;仿真验证了理论分析正确性.试验得到绳最大紧边压力为8 N,实际摩擦力7.6 N;钢丝绳选用304不锈钢,直径定为1.5 mm,最大承重25 kg.
基金supported by the National Natural Science Foundation of China (Grant Nos. 90923003, 10874234, 20703064 and 10804015)the Natural Science Foundation of Liaoning Province (Grant No. 20102039)
文摘We obtained n-type and p-type modified graphene by mixing quantum dots and depositing electron-acceptor molecules on the surface of graphene, respectively. The electrical and optical properties of these two types of samples were measured. For n-type modified graphene, the electrons were transferred from quantum dots to graphene. The resistance of these quantum dots in modified n-type graphene is significantly smaller than that of pristine graphene. For p-type graphene, modified by electron-acceptor organic molecules of tetracyanoethylene (TCNE), electrons were transferred from graphene to TCNE molecules. The resistance of this molecular modified p-type graphene is about 10% larger than that of pristine graphene. The charge transfer effect on the optical properties of graphene was investigated with Raman spectra.
