基于特征点识别的位姿测量数据处理方法研究

视觉测量具有结构简单、成本低、非接触式测量的优点,利用视觉位姿测量结果对空间展开机构进行定位具有良好的应用前景.实际应用中需要将视觉测量数据转换到物空间坐标系从而对定位系统的控制量提供指导.针对相机外参数标定操作繁琐、需要额外设备、不利于在轨实现等缺点,提出了一种利用运动样本空间构建坐标系转换关系的数据处理方法,根据取样空间内构建的补偿方程,可以将各自由度的视觉测量数据转换到控制器坐标系上,同时能够校正由于安装、配准等导致的系统误差,从而实现高精度的空间 目标定位.实验结果表明,在1.7 m的测量距离下,所搭建单相机测量系统的位置与转角测量精度可达0.02 mm和0.003°,验证了所研究方法的有效性和实用性.     

含氧空位的氟掺杂二氧化锰助力稳定锌离子电池

将无机盐NH₄F加入到MnO₂的前驱体溶液中,通过高效、简单的一步水热法制备了具有氧缺陷的F掺杂α-MnO₂纳米棒(记为F-MnO₂)。氧空位和F掺杂对提高F-MnO₂的导电性、促进离子扩散、提高倍率性能起着至关重要的作用。另外,由于F掺杂,形成了F—Mn键,这可以有效地抑制放电产物中Mn³⁺的Jahn-Teller畸变,从而提高结构的稳定性。得益于这些协同效应,组装的Zn||F-MnO₂全电池在0.5 A·g^-1下,首圈放电比容量高达274 mAh·g^-1,且具有较长的循环寿命和优异的倍率性能。同时,通过循环伏安(CV)和恒流充放电(GCD)曲线证明了F-MnO₂的储能机制为H⁺和Zn²⁺的共嵌入/脱出过程。     

三光气与酚制备三氯甲氧基甲酸芳酯研究

研究了不同取代酚与三光气的反应,得到七种未见报道的新化合物,以IR、MS、1H NMR、13C NMR对产物进行了表征,并探索得到合适的反应催化剂、反应物浓度配比、反应时间,讨论了酚上不同取代基对反应的影响,收率在78.5～90.5%之间。     

Effects of the laser surface treatment on the mechanical properties of CuZr-based bulk metallic glasses

Surfaces of three types of CuZr-based bulk metallic glasses (BMGs) were modified by laser surface treatment (LST), and the influence of the treatment on structure and mechanical properties of these alloys was investigated. The phase structure of as-cast and laser-treated samples was characterized by XRD and the morphology of the alloys after fracture was examined by SEM. The compressive plasticity of treated Cu47.5Zr47.5Al5 and Cu46.5Zr47.5Al5Co1 BMGs can be improved from 0.5% to 2.0% and from 1.2% to 5.7% respectively compared with the as-cast ones, while (Cu0.55Zr0.40Al0.05)99Er1 BMG shows insignificant change of plasticity. The improvement in plasticity is attributed to induced crystallization of B2 CuZr phase in the treated surface zone of selected metallic glasses.     

Magnetic properties and magnetocaloric effects in amorphous and crystalline Gd55Co35Ni10 ribbons

The magnetic properties and magnetocaloric effects of amorphous and crystalline Gd55Co35Ni10 ribbons are investigated.A main phase with a Ho 12 Co 7-type monoclinic structure(space group P21/c) and a minor phase with a Ho4Co3-type hexagonal structure(space group P63/m) are obtained for crystalline ribbon after annealing.The amorphous ribbons order ferromagnetically and undergo a second-order transition at 192 K.For crystalline Gd55Co35Ni10 ribbons,two magnetic phase transitions occur at 158 and 214 K,respectively.The peak value of-△SM under a field change of 0-5 T is 6.5 J/kg K at 192 K for amorphous Gd55Co35Ni10 ribbons.A relatively large magnetic entropy change(～5.0 J/kg K) under a field change of 0-5 T for the crystalline Gd55Co35Ni10 ribbons is obtained in the temperature interval range of 154-214 K.The large platform of magnetic entropy change and the negligible thermal/magnetic hysteresis loss mean the crystalline Gd55Co35Ni10 compound can satisfy the requirement of the Ericsson-type refrigerator working in the temperature range from 154K to 214K.     

Trapping and diffusion behaviors of helium at vacancy in iron from first principles

We investigate the structure,trapping,and diffusion behaviors of helium(He) at vacancy in a Fe single crystal using first-principles simulations.Vacancy with more space can provide the lower electron density region for He binding in comparison with intrinsic Fe,causing He to diffuse into the vacancy inner easily.We provide the quantitative microscopic studies related to the atomic-level thermo-kinetic trapping processes.Moreover,such physical viewpoint can be applied to other vacancy-like defects such as vacancy clusters,void and grain boundaries which can open a space with reduced electron density region to increase He binding in metals and metal alloys.     

Optical bistability based on surface plasmon coupled between two noble metal films involving Kerr materials

We successfully investigate an optical bistability phenomenon in a layered structure consisting of Kretschmann configuration involving the Kerr-type nonlinear and the silver film. Pure theoretical approaches are employed to investigate that the surface plasmon could easily be coupled and both the reflection and transmission curves versus the incident intensity forms optical bistability. The transmission curves are greatly influenced by the thickness of the second silver film. These results may be useful for designing novel surface plasmon-based optical devices and will be essential for future classical and quantum information processes.     

Electrochemical analysis of dye adsorption on aligned carbon nanofiber arrays coated with TiO2 nanoneedles for dye-sensitized solar cell

An electrochemical method has been developed to analyze dye absorption on the aligned carbon nanofiber arrays coated with TiO2 nanoneedles for dyesensitized solar cell. The unique nanostructure with the roughness factor of 90.6 provides a large effective surface area for dye adsorption. The experimental results showed that the dye molecules cover 39.7% of the TiO2 surface area which influences the performance of dye-sensitized solar cell. The electrochemical method provides the information of the coverage of dye molecules which is a key issue to optimize solar cell performance.