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Chinese Journal of Aeronautics 2023年第12期36卷 451-460页

作者： Jinchuan TIAN Mingjun CHEN Jian CHENG henan liu State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

Hemispherical shell resonator(HSR)is the core component of hemispherical resonator *** is aφ-shaped small-bore complex component with minimum curvature radius less than 3 ***,traditional polishing methods are difficult to polish *** ball-end magnetorheological polishing method can polish the small components with complicated three-dimensional surface and obtain non-destructive ***,this method is suitable for polishing ***,the material removal rate of the ordinary small ball-end magnetorheological polishing is low,leading to long polishing time and low output of *** solve this problem,a water bath heating assisted small ball-end magnetorheological polishing method is proposed in this *** influence rule of processing parameters on the material removal rate is studied experimentally.A set of optimal processing parameters is obtained to maximize the material removal *** with the ordinary method,the material removal rate of the new method can be improved by 143%.Subsequently,an HSR is polished by the new *** results show that the polishing time can be reduced by 55%,and the polished surface roughness can reach 7.7 *** new method has the great potential to be used in actual production to improve the polishing efficiency of HSR.

关键词： Hemispherical shell resonator Magnetorheological fluid temperature Material removal rate Optimization Small ball-end magnetorheological polishing

Interference and grinding characteristics in ultra-precision grinding of thin-walled complex structural component using a ball-end grinding wheel

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Chinese Journal of Aeronautics 2021年第4期34卷 192-207页

作者： Tingzhang WANG henan liu Chunya WU Jian CHEN Mingjun CHEN Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

As for ultra-precision grinding of difficult-to-process thin-walled complex components with ball-end grinding wheels,interference is easy to *** to screw theory and grinding kinematics,a mathematical model is established to investigate the interference and grinding characteristics of the ball-end *** relationship between grinding wheel inclination angle,C axis rotation angle,grinding position angle and grinding wheel wear are *** the grinding wheel inclination angle increases,the C axis rotatable range decreases and the grinding position angle *** grinding position angle and wheel radius wear show a negative correlation with the C axis rotation ***,a trajectory planning criteria for increasing grinding speed as much as possible under the premise of avoiding interference is proposed to design the grinding *** grinding point distribution on the ball-end wheel is calculated,and the grinding characteristics,grinding speed and maximum undeformed chip thickness,are ***,a complex structural component can be ground without interference,and surface roughness and profile accuracy are improved to 40.2 nm and 0.399 lm,compared with 556 nm and 3.427 lm before ultra-precision *** mathematical model can provide theoretical guidance for the analysis of interference and grinding characteristics in complex components grinding to improve its grinding quality.

关键词： Ultra-precision grinding Complex component Ball-end grinding wheel Interference Grinding characteristics

Magnetorheological finishing of an irregular-shaped small-bore complex component using a small ball-end permanent-magnet polishing head

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Nanotechnology and Precision Engineering 2019年第3期2卷 125-129页

作者： henan liu Jian Cheng Tingzhang Wang Mingjun Chen School of Mechatronics Engineering Harbin Institute of Technology

A novel magnetorheological finishing(MRF)process using a small ball-end permanent-magnet polishing head is proposed,and a four-axes linkage dedicated MRF machine tool is fabricated to achieve the nanofinishing of an irregularψ-shaped small-bore complex component with concave surfaces of a curvature radius less than3 *** processing method of the complex component is *** simulation during the entire finishing path is carried out to analyze the material removal characteristics.A typicalψ-shaped small-bore complex component is polished on the developed device,and a fine surface quality is obtained with surface roughness Raof 0.0107μm and surface accuracy of the finished spherical surfaces of 0.3320μm(PV).These findings indicate that the proposed MRF process can perform the nanofinishing of a kind of small-bore complex component with small-curvature-radius concave surfaces.

关键词： Complex component Magnetorheological finishing Magnetostatic simulation Small curvature radius

Experimental and modeling study of surface topography generation considering tool-workpiece vibration in high-precision turning

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Chinese Journal of Aeronautics 2023年第7期36卷 194-212页

作者： Xingying ZHOU henan liu Tianyu YU Ruiyang GUO Guangzhou WANG Yazhou SUN Mingjun CHEN State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China

High-precision turning(HPT)is a main processing method for manufacturing rotary high-precision components,especially for metallic ***,the generated vibration between tool tip and workpiece during turning may seriously deteriorate the surface ***,exploring the effect of vibration on turning surface morphology and quality of copper parts using 3D surface topography regeneration model is crucial for predicting HPT *** developed model can update the machined surface topology in real *** this study,the effects of tool arc radius,feed rate,radial vibration,axial vibration and tangential vibration on the surface topography and surface roughness were *** results show that the effect of radial vibration on surface topography is greater than that of axial vibration and tangential *** radial vibration frequency is also *** vibration frequency changes,the surface topography profile presents three different types:the standard sinusoidal curve,the sinusoidal curve whose lowfrequency signal envelopes high-frequency signal,and the oscillation curve whose low-frequency signal superimposes high-frequency *** addition,HPT experiment was carried out to validate the developed *** surface roughness obtained in the experiment was Ra=53 nm,while the roughness obtained by the simulation was Ra=46 nm,achieving a prediction accuracy of 86.7%.Received 4 September 2022;revised 3 October 2022;accepted 17 October 2022.

关键词： High-precision turning Machining vibration Modeling Surface roughness Surface topography

Hemispherical resonator with low subsurface damage machined by small ball-end fine diamond grinding wheel:A novel grinding technique

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Chinese Journal of Aeronautics 2024年第5期37卷 570-585页

作者： Biao QIN henan liu Jian CHENG Jinchuan TIAN Jiangang SUN Zihan ZHOU Chuanzhen MA Mingjun CHEN State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

As for the ultra-precision grinding of the hemispherical fused silica resonator,due to the hard and brittle nature of fused silica,subsurface damage(SSD)is easily generated,which enormously influences the performance of such ***,ultra-precision grinding experiments are carried out to investigate the surface/subsurface quality of the hemispherical resonator machined by the small ball-end fine diamond grinding *** influence of grinding parameters on the surface roughness(SR)and SSD depth of fused silica samples is then *** experimental results indicate that the SR and SSD depth decreased with the increase of grinding speed and the decrease of feed rate and grinding *** addition,based on the material strain rate and the maximum undeformed chip thickness,the effect of grinding parameters on the subsurface damage mechanism of fused silica samples is ***,a multi-step ultra-precision grinding technique of the hemispherical resonator is proposed based on the interaction influence between grinding depth and feed ***,the hemispherical resonator is processed by the proposed grinding technique,and the SR is improved from 454.328 nm to 110.449 nm while the SSD depth is reduced by 94%from 40μm to 2.379μ*** multi-step grinding technique proposed in this paper can guide the fabrication of the hemispherical resonator.

关键词： Fused silica Ultra-precision grinding Hemispherical resonator Subsurface damage Grinding technique

Carrier behavior in the vicinity of pit defects in GaN characterized by ultraviolet light-assisted Kelvin probe force microscopy

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Science China(Physics,Mechanics & Astronomy) 2019年第6期62卷 87-92页

作者： CuiHong Kai XiaoJuan Sun Yu Ping Jia ZhiMing Shi Ke Jiang JianWei Ben You Wu Yong Wang henan liu XiaoHang Li DaBing Li State Key Laboratory of Luminescence and Applications Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences King Abdullah University of Science and Technology (KAUST) Advanced Semiconductor Laboratory

Surface potentials in the vicinity of V-pits(cone bottom) and U-pits(blunt bottom) on epitaxial GaN surface have been systematically studied using ultraviolet(UV) light-assisted Kelvin probe force microscopy(KPFM). The band structure models are established to understand variation of the surface potentials at the pits and planar surface with and without UV light. The photo-generated carrier behavior at the pit defects is studied. According to the surface potential results, it can be deduced that the carrier distributions around the V-and U-pits are uneven. In dark, the electron concentration at the bottom of V-pit(30 n_0) and Upit(15 n_0) are higher than that at planar surface(n_0). Under UV light, for V-pit, the electron concentration at the cone bottom(4.93×10^(11) n_0) is lower than that at the surrounding planar surface(5.68×10^(13) n_0). For U-pit, the electron concentration at the blunt bottom is 1.35×10^(12) n_0, which is lower than that at the surrounding planar surface(6.13×10^(13) n_0). The non-equilibrium electron concentrations at different locations are calculated. Based on the non-equilibrium electron concentration, it can be concluded that the carrier recombination rate at pit defects is higher than that at planar surface.

关键词： pit defects surface potential electron concentration

Mechanical Properties of Railway High-strength Manufactured Sand Concrete: Typical Lithology, Stone Powder Content and Strength Grade

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 194-203页

作者： WANG Zhen LI Huajian HUANG Fali YANG Zhiqiang WEN Jiaxin SHI henan Railway Engineering Research Institute China Academy of Railway Science Corporation LimitedBeijing 100081China State Key Laboratory for Track Technology of High-Speed Railway Beijing 100081China

In order to achieve the large-scale application of manufactured sand in railway high-strength concrete structure,a series of high-strength manufactured sand concrete(HMC)are prepared by taking the manufactured sand lithology(tuff,limestone,basalt,granite),stone powder content(0,5%,10%,15%)and concrete strength grade(C60,C80,C100)as *** evolution of mechanical properties of HMC and the correlation between cubic compressive strength and other mechanical properties are *** to river sand,manufactured sand enhances the cubic compressive strength,axial compressive strength and elastic modulus of concrete,while its potential microcracks weaken the flexural strength and splitting tensile strength of *** powder content displays both positive and negative effects on mechanical properties of HMC,and the stone powder content is suggested to be less than 10%.The empirical formulas between cubic compressive strength and other mechanical properties are proposed.

关键词： manufactured sand concrete railway mechanical property lithology stone powder content

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转让股东“反悔”中的规范秩序

社会科学战线 2020年第7期 197-205页

作者：于莹刘赫男吉林大学法学院吉林长春130012

有限责任公司股权转让中,在其他股东行使优先购买权后转让股东可以反悔,不再转让股权,经《公司法司法解释(四)》的确认,统一了此类案件的裁判标准。但理由层面的争论未因司法解释的颁布而消失。文章综合股权性质、内容和本质以及优先购... 详细信息

有限责任公司股权转让中,在其他股东行使优先购买权后转让股东可以反悔,不再转让股权,经《公司法司法解释(四)》的确认,统一了此类案件的裁判标准。但理由层面的争论未因司法解释的颁布而消失。文章综合股权性质、内容和本质以及优先购买权制度的目的等多种因素,探寻股东优先购买权在公司法和合同法中建立的规范秩序和行为价值,对赔偿合理信赖损失下转让股东反悔的正当性进行了全面论证,认为转让股东的反悔符合《公司法》和《合同法》的规范结构,符合比例原则在私法中的应用,应得到《公司法》和《合同法》的规范支持。

关键词：转让股东反悔规范秩序行为价值比例原则

The Redox State of Ascorbate Pool Affects Early-flowering Induced by Low Temperature in Tobacco

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The Redox State of Ascorbate Pool Affects Early-flowering In...

中国生物化学与分子生物学会农业生物化学与分子生物学分会第八次学术研讨会

作者： Yongchun Shi Weiqun liu (henan Agricultural Universtiy,National Key Lab of Tobacco Planting and Physiology and Biochemistry)

The early-flowering induced by low temperature affects the quality and quantity of tobacco *** the molecular mechanisms of this phenomenon is the key way to solve this *** (SUPPRESOR OF OVEREXPRESSION OF CO1) is a central flowering time pathway integrator which finally leads to the activation of floral meristem identity genes and the formation of *** ascorbate oxidase (AO) and the dehydroascorbate reductase (DHAR) catalyze the oxidation of ascorbic acid (AsA) and the reduction of dehydroascorbate *** flowering time would be affected by over expression or inhibition *** haven’t been reported that whether the early-flowering induced by low temperature is regulated by the redox state of ascorbic acid.

关键词： low temperature early-flowering SOCl ascorbic acid

来源： cnki会议评论

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基于粗糙集的变压器故障诊断方法研究

仪器仪表学报 2006年第Z1期27卷 385-386页

作者：孙秋野张化光刘贺男东北大学信息科学与工程学院沈阳110004

本文提出了一种布尔逻辑与粗糙集相结合的变压器连续属性离散化方法,用计算机仿真实例说明算法的有效性。在变压器故障诊断中,首次将连续和离散信号统一应用粗糙集进行约简。通过这种方法,能够对变压器故障诊断模型进行更精确的模拟,从... 详细信息

本文提出了一种布尔逻辑与粗糙集相结合的变压器连续属性离散化方法,用计算机仿真实例说明算法的有效性。在变压器故障诊断中,首次将连续和离散信号统一应用粗糙集进行约简。通过这种方法,能够对变压器故障诊断模型进行更精确的模拟,从而提高故障辨识的精度。

关键词：粗糙集离散化布尔逻辑变压器