Effect of Tilt Angle of Surface to be Measured on Differential Confocal Microscope Pointing Signal

普通共焦显微镜的轴向响应特性,因受到被测量表面的倾斜角影响引从而起轴向响应特性变化,而应用差动共焦光学系统对超精密加工的表面进行瞄准测量时,差动系统的瞄准信号也受到影响,并进而影响到测量系统对加工表面的测量精度及分辨特性。通过对差动共焦测量系统输出信号理论模型的分析得出被测量面的倾斜角变化不影响差动共焦输出信号零点位置;倾角在一定范围内变化时不影响瞄准测量分辨力的结论,并给出了实验分析结果。The axial response of conventional confocal microscope is affected by the tilt angle of the surface to be measured.When the ultra-precisely machined surface is measured with pointing method based on the differential confocal microscope,the tilt angle of the surface to be measured influences the pointing signal,as well as the measuring accuracy and resolution of the treated surface.On the basis of the analysis of the theoretical model of the output signal of differential confocal microscope,it is concluded that the zero point is independent of the tilt angle of surface to be measured and the resolution of the pointing signal is not affected with the tilt angle in a certain range.The experimental results are also presented

Properties of a Si 2 N molecule under an external electric field *

In the present work, we adopt the ccsd/6-31g(d) method to optimize the ground state structure and calculate the vibrational frequency of the Si 2 N molecule. The calculated frequencies accord satisfactorily with the experimental values, which helps confirm the ground state structure of the molecule. In order to find how the external electric field affects the Si 2 N molecule, we use the density functional method B3P86/6-31g(d) to optimize the ground state structure and the time-dependent density functional theory TDDFT/6-31g(d) to study the absorption spectra, the excitation energies, the oscillator strengths, and the dipole moments of the Si 2 N molecule under different external electric fields. It is found that the absorption spectra, the excitation energies, the oscillator strengths, and the dipole moments of the Si 2 N molecule are affected by the external electric field. One of the valuable results is that the absorption spectra of the yellow and the blue-violet light of the Si 2 N molecule each have a red shift under the electric field. The luminescence mechanism in the visible light region of the Si 2 N molecule is also investigated and compared with the experimental data

煤矸石智能分拣机器人研究进展与关键技术

煤矿井下矸石被煤泥包裹，煤矸石识别难、分拣难；井下工作空间狭小，设备布局难、煤矸石分流难，因此，需要研发高性能、高可靠的煤矸石智能分拣机器人。分析了煤矸石智能分拣机器人中煤矸石识别、机器人轨迹规划、多动态目标多机器人协同控制技术的研究现状。指出煤矸石分拣工作环境复杂，其质量和形状不规则且呈随机分布，因此，复杂环境下煤矸石识别与抓取特征提取、非结构环境下煤矸石稳定可靠抓取、多目标任务多机器人智能协同分拣是煤矸石分拣智能机器人的3大关键技术，提出要实现机器人智能分拣煤矸石，还应在适应于井下的煤矸石识别与抓取特征提取、动态目标精确定位和同步跟踪、机械臂在线轨迹规划和多机械臂智能协同控制等方法上进行深入研究。通过对上述3大关键技术的梳理，总结得出：煤矸石数据集构建与扩增、煤矸石识别与抓取特征提取是实现煤矸石高效识别的关键技术；动态煤矸石精准跟踪、机械臂同步跟踪动态目标轨迹规划和快速大质量目标稳定抓取是实现机械臂稳定抓取煤矸石的关键技术；多任务高效分配、防碰撞路径规划和智能协同控制是实现多机械臂高效智能协同分拣的关键技术。针对目前存在的共性问题，提出了解决方案：在识别方面，研究基于多模态深度学习的煤矸石识别与抓取特征提取方法，实现井下煤矸石快速识别；在轨迹规划方面，研究动态煤矸石精准定位和实时跟踪方法，实现机器人对动态煤矸石的自适应稳定抓取；在协同分拣方面，构建多层多机械臂协同控制模型，实现多机械臂复杂环境下高效智能协同分拣

石墨表面镀Si对石墨/Al复合材料热物理性能的影响

研究了石墨粒径及表面镀Si处理对石墨/Al复合材料热物理性能的影响。结果表明:在盐浴过程中石墨表面形成了SiC层,这不仅增强了石墨-Si/Al复合材料的界面结合力,而且抑制了Al4C3相的产生。随着石墨鳞片体积分数从50%增加到70%,复合材料X-Y方向的热导率从492 W/(m·K)增加到654 W/(m·K),而且体积分数为50%的镀Si石墨/Al复合材料抗弯强度达到了81 MPa,相比未镀覆的提高了53%,是理想的定向导热电子封装材料。随着石墨粒径从500μm减小到150μm,石墨-Si/Al复合材料X-Y面方向的热导率由654 W/(m·K)降低到445 W/(m·K),但Z方向的热导率和复合材料抗弯强度变化不明显