Fiber optics underpins the communication infrastruture of today＇s information society. Rapid rogl：ess in advanced modulation formats, high＇gain coding, optical amplification, coherent detection with digital signal ...Fiber optics underpins the communication infrastruture of today＇s information society. Rapid rogl：ess in advanced modulation formats, high＇gain coding, optical amplification, coherent detection with digital signal processing, and new展开更多
The surface integrity of metal micro-hole structures produced by electrochemical discharge machining is unsatisfactory owing to the insufficient reaction area and strength of electrolysis action.A novel ultrahigh-spee...The surface integrity of metal micro-hole structures produced by electrochemical discharge machining is unsatisfactory owing to the insufficient reaction area and strength of electrolysis action.A novel ultrahigh-speed Rotary Electrochemical Discharge Machining(R-ECDM)using non-water-based electrolyte is proposed to improve surface integrity by changing the breakdown medium of spark discharge and increasing the reaction area and strength of electrolysis.A mathematical model was developed to establish the relationship between rotational speed and forces acting on the bubble.Based on the magnitude of forces,controlling rotational speed changed the behavior and departure radius of bubbles on the cathode surface.High-speed photographs validate that,in the mathematical model,the number and departure radius of bubbles on the cathode surface gradually decrease with the increase of rotational speed.The experimental results show that the roughness(Ra)of the micro-hole sidewall decreases from 2.54μm to 0.20μm when the rotational speed increases from 500 r/min to 40000 r/min.The length loss and wear ratio of the cathode are only 9.75μm and 6.5%,respectively.Finally,the micro-holes array with recast-free and surface roughness of 0.20μm is fabricated,demonstrating that the proposed approach contributes to improving surface integrity of metal micro-holes.展开更多
为满足卷烟生产设备高速传动的要求,对H1000超高速包装机组的差动式模盒机构的工作原理和运动特性进行了分析。该模盒机构采用凸轮差速传动和交替运动方式,由凸轮机构产生差速,通过行星齿轮差速器与主传动并联,以满足机构的间隙运动需求...为满足卷烟生产设备高速传动的要求,对H1000超高速包装机组的差动式模盒机构的工作原理和运动特性进行了分析。该模盒机构采用凸轮差速传动和交替运动方式,由凸轮机构产生差速,通过行星齿轮差速器与主传动并联,以满足机构的间隙运动需求,降低高速运转时的冲击和噪声;利用两组模盒交替运动方式提高设备的工作效率。结果表明:差动式模盒机构可以较好地满足超高速包装机组的连续稳定运行的要求,加减速柔和,运动冲击小;设备全速运转噪声仅为79 d B,低于中速包装机组的83 d B;3年实测故障率为零,各零部件无明显磨损。对该模盒机构的原理、结构和运行特性研究可为新型超高速包装机组的技术研发提供参考。展开更多
文摘Fiber optics underpins the communication infrastruture of today＇s information society. Rapid rogl：ess in advanced modulation formats, high＇gain coding, optical amplification, coherent detection with digital signal processing, and new
基金The authors acknowledged the financial support provided by the National Natural Science Foundation of China(No.91960204)the Natural Science Foundation of Jiangsu Province,China(No.BK20222010)+3 种基金the National Natural Science Foundation of China for Creative Research Groups(No.51921003)the Project of Science Center for Gas Turbine Project,China(No.HT-P2022-B-IV-010-001)the Fundamental Research Funds for the Central Universities,China(No.NP2022422)the Experimental Technology Research and Development Project in Nanjing University of Aeronautics and Astronautics,China(No.SYJS202203Z).
文摘The surface integrity of metal micro-hole structures produced by electrochemical discharge machining is unsatisfactory owing to the insufficient reaction area and strength of electrolysis action.A novel ultrahigh-speed Rotary Electrochemical Discharge Machining(R-ECDM)using non-water-based electrolyte is proposed to improve surface integrity by changing the breakdown medium of spark discharge and increasing the reaction area and strength of electrolysis.A mathematical model was developed to establish the relationship between rotational speed and forces acting on the bubble.Based on the magnitude of forces,controlling rotational speed changed the behavior and departure radius of bubbles on the cathode surface.High-speed photographs validate that,in the mathematical model,the number and departure radius of bubbles on the cathode surface gradually decrease with the increase of rotational speed.The experimental results show that the roughness(Ra)of the micro-hole sidewall decreases from 2.54μm to 0.20μm when the rotational speed increases from 500 r/min to 40000 r/min.The length loss and wear ratio of the cathode are only 9.75μm and 6.5%,respectively.Finally,the micro-holes array with recast-free and surface roughness of 0.20μm is fabricated,demonstrating that the proposed approach contributes to improving surface integrity of metal micro-holes.
文摘为满足卷烟生产设备高速传动的要求,对H1000超高速包装机组的差动式模盒机构的工作原理和运动特性进行了分析。该模盒机构采用凸轮差速传动和交替运动方式,由凸轮机构产生差速,通过行星齿轮差速器与主传动并联,以满足机构的间隙运动需求,降低高速运转时的冲击和噪声;利用两组模盒交替运动方式提高设备的工作效率。结果表明:差动式模盒机构可以较好地满足超高速包装机组的连续稳定运行的要求,加减速柔和,运动冲击小;设备全速运转噪声仅为79 d B,低于中速包装机组的83 d B;3年实测故障率为零,各零部件无明显磨损。对该模盒机构的原理、结构和运行特性研究可为新型超高速包装机组的技术研发提供参考。
