蝗虫爪尖能够形成用于稳固附着的机械锁合,抑制蝗虫在捕集滑板表面的滑移行为。为获取用于蝗虫捕集滑板研制的爪尖强度信息,利用自行设计的昆虫微力测试系统测试了蝗虫前足、中足、后足爪尖的剪切力;采用扫描电镜（scanning electron mi...蝗虫爪尖能够形成用于稳固附着的机械锁合,抑制蝗虫在捕集滑板表面的滑移行为。为获取用于蝗虫捕集滑板研制的爪尖强度信息,利用自行设计的昆虫微力测试系统测试了蝗虫前足、中足、后足爪尖的剪切力;采用扫描电镜（scanning electron microscopy,SEM）分析了蝗虫爪尖及其断裂面的微形貌结构与几何特征,计算了爪尖断裂面的截面积,并据此测算了蝗虫爪尖的剪切强度。结果表明爪尖的剪切力介于197.4~243.6 mN,其中前足爪尖的剪切力最大,后足居中,中足最小;爪尖断裂面表现出层状的复合结构且具有显著不同的截面积（10 847.6~13 908.5μm2）;测算结果表明蝗虫爪尖的剪切强度介于14.2~22.5 MPa。该研究可为研制具有良好滑移功能蝗虫捕集滑板提供参考,并可促进灾害蝗虫光电诱导滑移捕集技术的发展。展开更多
A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS ...A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.展开更多
为解决微电子机械系统(MEMS)器件三维尺寸高精度测量的难题,研制了一种适用于微纳米三坐标测量机的新型高精度三维接触触发式探头。该探头只用了一个基于四象限感测器的二维角度传感器即可同时实现对测球三维运动的高精度感测。介绍了...为解决微电子机械系统(MEMS)器件三维尺寸高精度测量的难题,研制了一种适用于微纳米三坐标测量机的新型高精度三维接触触发式探头。该探头只用了一个基于四象限感测器的二维角度传感器即可同时实现对测球三维运动的高精度感测。介绍了探头的结构和原理,建立了探头的灵敏度模型和刚度模型,用最优化方法得出了探头结构参数的最优解。对探头的刚度、感测范围、灵敏度、稳定性及触发重复性等性能指标进行了测试。实验结果表明:探头的刚度在三轴方向基本相同,约为1 m N/μm;允许触碰范围超过12μm;灵敏度大于0.5 m V/nm;在恒温环境(20±0.025)℃下,1.3 h内的位移漂移量约为20 nm;触发测量重复性小于40 nm(K=2)。该探头具有精度高、测力小、体积小、成本低、装调方便等优点,可被用于微纳米三坐标测量机。展开更多
文摘A high temperature superconducting(HTS)magnetically levitated testbed has been developed for the steady thrust measurement of miniature ion electrospray thruster.The structure of the testbed mainly consists of an HTS composite bearing,a magnetic shielding plate,an active electromagnetic brake and a laser displacement sensor.The steady thrust is described as a function of the equilibrium angle displacement of the floating frame.Furthermore,the mechanical behaviors of HTS composite bearing were studied via finite element simulation and experiments,which include the load capacity,levitation stiffness and background noise.The results show that the thrust testbed can keep in low noise and have a load capacity up to 4 kg.According to the ignition testing of the electrospray thruster,the thrust force of 25.2 m N was measured by the testbed,which is close to the design value of miniature ion electrospray thruster.
文摘为解决微电子机械系统(MEMS)器件三维尺寸高精度测量的难题,研制了一种适用于微纳米三坐标测量机的新型高精度三维接触触发式探头。该探头只用了一个基于四象限感测器的二维角度传感器即可同时实现对测球三维运动的高精度感测。介绍了探头的结构和原理,建立了探头的灵敏度模型和刚度模型,用最优化方法得出了探头结构参数的最优解。对探头的刚度、感测范围、灵敏度、稳定性及触发重复性等性能指标进行了测试。实验结果表明:探头的刚度在三轴方向基本相同,约为1 m N/μm;允许触碰范围超过12μm;灵敏度大于0.5 m V/nm;在恒温环境(20±0.025)℃下,1.3 h内的位移漂移量约为20 nm;触发测量重复性小于40 nm(K=2)。该探头具有精度高、测力小、体积小、成本低、装调方便等优点,可被用于微纳米三坐标测量机。
