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  • Structure design and fabricating methods of three-dimensional(3D)artificial spherical compound eyes have been researched by many scholars.Micro-nano optical manufacturing is mostly used to process 3D artificial compound eyes.However,spherical optical compound eyes are less at optical performance than the eyes of insects,and it is difficult to further improve the imaging quality of compound eyes by means of micro-nano optical manufacturing.In this research,nonhomogeneous aspheric compound eyes(ACEs)are designed and fabricated.The nonhomogeneous aspheric structure is applied to calibrate the spherical aberration.Micro milling with advantages in processing three-dimensional micro structures is adopted to manufacture ACEs.In order to obtain ACEs with high imaging quality,the tool paths are optimized by analyzing the influence factors consisting of interpolation allowable error,scallop height and tool path pattern.In the experiments,two kinds of ACEs are manufactured by micro-milling with different too path patterns and cutting parameter on the miniature precision five-axis milling machine tool.The experimental results indicate that the ACEs of high surface quality can be achieved by circularly milling small micro-lens individually with changeable cutting depth.A prototype of the aspheric compound eye(ACE)with surface roughness(Ra)below 0.12?m is obtained with good imaging performance.This research ameliorates the imaging quality of 3D artificial compound eyes,and the proposed method of micro-milling can improve surface processing quality of compound eyes.
     - 中国机械工程学报
    文章来源: 万方数据
  • Micro-gas turbine engine(MTE) rotor is an important indicator of its property, therefore, the manufacturing technology of the microminiature rotor has become a hot area of research at home and abroad. At present, the main manufacturing technologies of the MTE rotor are directed forming fabrication technologies. However, these technologies have a series of problems, such as complex processing technology high manufacturing cost, and low processing efficiency, and so on. This paper takes advantage of micro electric discharge machining(micro-EDM) in the field of microminiature molds manufacturing, organizes many processing technologies of micro-EDM reasonably to improve processing accuracy, presents an integrated micro-EDM technology and its process flow to fabricate MTE rotor die, and conducts a series of experiments to verify efficiency of this integrated micro-EDM. The experiments results show that the MTE rotor die has sharp outline and ensure the good consistency of MTE rotor blades. Meanwhile, the MTE rotor die is applied to micro extrusion equipment, and technologies of micro-EDM and micro forming machining are combined based on the idea of the molds manufacturing, so the MTE rotor with higher aspect ratio and better consistency of blades can be manufactured efficiently. This research presents an integrated micro-EDM technology and its process flow, which promotes the practical process of MTE effectively.
     - 中国机械工程学报
    文章来源: 万方数据
  • Durning the design process of hydrostatic rotary worktable,the processing and assembly tolerance,(the offset of worktable and the gap of the oil film's thickness)is ignored.But it will cause that the real bearing of oil pocket deviates from the initial design value,and then the performance of rotary worktable will be reduced significantly.Up to now,no effort is found toward the research of influence of the processing and assembly tolerance on the performance of the rotary worktable.So the hydrostatic oil film is assumed as the elastomer in this paper,and then the bearing capacity of the oil pocket is studied with and without the mass offset of the worktable by taking an expression between the bearing capacity and the oil film's thickness of the oil pocket as the deform compatibility equation.The influence of the processing tolerance of the oil sealing belt's gap on the bearing capacity of the oil pocket is analyzed.In the light of the liquid hydrostatic worktable of Gantry Moving Milling Center using on the scene,the oil pocket's pressure of the worktable is tested using Rotary Worktable Test System under the circumstance of the mass offset of the worktable and the gap tolerance of the oil sealing belt,and then the equivalent offset of worktable,the average pressure of the oil pocket and the actual thickness of the oil film are analyzed respectively.The test results show that the bearing capacity component of the oil pocket caused by G is consistent,and the component caused by M is relative to the position of the oil pocket.When the oil sealing belt's gap is larger than the theoretical value,the bearing capacity of the oil pocket is smaller than the others;whereas the bearing capacity of the oil pocket is larger than the others.The maximum and minimum equivalent offsets are 0.256 4 mm and 0.047 5 mm,respectively,and the average oil pocket pressure varies from 0.345 MPa to 0.460 MPa,the maximum and minimum value of the actual oil film thickness are 109.976?m(No.7 oil pocket)and 93.467?m(No.10 oil pocket),respectively.The research results can be used to detect the offset of the worktable and the actual thickness of the oil film under processing and assembly tolerance,and provides a basis way for detecting the processing and assembly tolerance of rotary worktable signing reasonably of Gantry Moving Milling Center.
     - 中国机械工程学报
    文章来源: 万方数据
  • 基于.Net Micro Framework的电动汽车充电桩控制系统的设计

    针对电动汽车充电桩控制系统开发周期长、扩展能力差的问题,设计了一种基于.Net Micro Framework的电动汽车充电桩控制系统.本系统基于Cortex-M3内核的开发板,采用了模块化设计原则,详细阐述了.Net Micro Framework在电动汽车充电桩控制系统中的开发流程和功能模块设计.本系统已在山东临沂焦庄、青岛薛家岛充换电站的充电桩上运行使用,运行结果表明该系统扩展能力强、开发成本低,运行更加稳定可靠.
    陈杰,李建祥,刘海波,付崇光 - 微计算机信息
    文章来源: 万方数据
  • 聚醚砜微图案膜的模板法制备及性能表征

    以聚醚砜(PES)为基质膜材料,利用微图案硅片为模板,通过非溶剂致相分离法(NIPS)制备PES微图案膜,研究制膜条件对膜表面微图案及膜结构、性能的影响,考察图案化前后PES膜的水通量、接触角、孔隙率、拉伸强度性能差异.结果表明,以模板法制得的PES 膜表面呈现规整的微图案,且膜表面微图案的规整性随铸膜液中PES浓度的增加而提高.接触角、孔隙率和水通量测试表明,相对于PES原膜,制得的微图案膜具有较高的接触角和较高的孔隙率及水通量;机械性能测试表明,图案化前后膜的拉伸强度变化不大.
    万伟娜,张玉忠,林立刚,丁晓莉,李泓 - 膜科学与技术
    文章来源: 万方数据
  • 高分辨率小动物Micro Insert PET系统的模拟研究

    在西门子Micro PET小动物成像系统中接入高分辨率的Insert探测器环,组成了Micro Insert PET系统,可以进一步提高小动物PET系统的图像分辨率.本文采用蒙特卡罗模拟软件GATE定义Focus-220小动物PET和Micro Insert两种系统,在同步仿真运算中,给出了三种类型的符合数据,即PET Scanner和PET Scanner之间的符合、PET Scanner和Insert之间的符合、Insert和Insert之间的符合.用滤波反投影算法重建了Na-22单点源模型、多点源模型、LZU模型的PET图像.其中,多点源模型的径向图像分辨率的仿真结果与美国华盛顿大学的Micro Insert实验数据,在忽略正电子射程、非线性效应项以及噪声等的贡献下,两者符合得很好.研究表明,使用Micro Insert系统能够将小动物PET系统的图像分辨率提高到亚毫米水平.
    尹永智,李梅春,王慧鹏,姚丽萍,叶征乾 - 核技术
    文章来源: 万方数据
  • 借鉴国际经验促进我国小微企业创新发展

    我国现行税收政策激励对小微企业创新发展作用不明显,缺乏足够的吸引力,需要借鉴发达国家的做法,建立促进小微企业创新发展的税收法律体系,引导小微企业用足刷好税收优惠政策,切实解决小微食业创新能力不足的问题.
    陈文裕 - 涉外税务
    文章来源: 万方数据
  • 等离子体法聚苯乙烯多孔板表面接枝顺丁烯二酸酐

    以浓度为2.5%的顺丁烯二酸酐乙醇溶液浸泡聚苯乙烯多孔板24 h后,用低温等离子体辐照引发,将顺丁烯二酸酐接枝到多孔板孔的表面.利用表面水接触角测试仪、X射线光电子能谱(XPS)、傅里叶红外光谱(FTIRATR)对其表面进行表征,并用酶标仪测定其在405 nm处空气空白的吸光度,结果表明:处理后的PS表面产生大量的含氧亲水基团,并且处理时间为60 s时,亲水性提高53.8%,吸光度提高31.3%.
    郑力行,王华山 - 塑料
    文章来源: 万方数据
  • There have been various theoretical attempts by researchers worldwide to link up different scales of plasticity studies from the nano-, micro- and macro-scale of observation, based on molecular dynamics, crystal plasticity and continuum mechanics. Very few attempts, however, have been reported in ultra-precision machining studies. A mesoplasticity approach advocated by Lee and Yang is adopted by the authors and is successfully applied to studies of the micro-cutting mechanisms in ultra-precision machining. Traditionally, the shear angle in metal cutting, as well as the cutting force variation, can only be determined from cutting tests. In the pioneering work of the authors, the use of mesoplasticity theory enables prediction of the fluctuation of the shear angle and micro-cutting force, shear band formation, chip morphology in diamond turning and size effect in nano-indentation. These findings are verified by experiments. The mesoplasticity formulation opens up a new direction of studies to enable how the plastic behaviour of materials and their constitutive representations in deformation processing, such as machining can be predicted, assessed and deduced from the basic properties of the materials measurable at the microscale.
     - 中国机械工程学报
    文章来源: 万方数据
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