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学者姓名：王民
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Abstract ：
针对滚珠丝杠副在低转速状态存在混合润滑导致丝杠滚道加速磨损的问题,基于等温弹流润滑理论建立了滚珠丝杠副弹流润滑接触模型研究滚珠与滚道间的摩擦机理和磨损形式.首先基于Frenet-Serret坐标转换方法建立丝杠与螺母的滚道曲面几何模型.其次基于Reynolds方程建立了滚珠丝杠副弹流润滑接触模型,求解了润滑油膜接触压力分布、油膜厚度分布和微凸体接触压力分布.最后从微观角度阐明了滚珠丝杠副的摩擦机理,其摩擦因数由微凸体接触摩擦因数和油膜润滑摩擦因数组成.实验结果表明:在低转速阶段丝杠滚道的磨损方式为黏着磨损和磨粒磨损,且模拟的摩擦因数曲线趋势和经典的Stribeck摩擦曲线趋势吻合较好,根据实测摩擦力矩准确识别了不同转速下滚珠丝杠副的摩擦因数和润滑状态.
Keyword ：
润滑状态 润滑状态 摩擦因数 摩擦因数 黏着磨损 黏着磨损 弹流润滑理论 弹流润滑理论 滚珠丝杠副 滚珠丝杠副 磨粒磨损 磨粒磨损
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| GB/T 7714 | 孙铁伟 , 王民 , 高相胜 et al. 基于等温弹流润滑理论的滚珠丝杠副摩擦机理研究 [J]. | 北京工业大学学报 , 2023 , 49 (1) : 1-10 . |
| MLA | 孙铁伟 et al. "基于等温弹流润滑理论的滚珠丝杠副摩擦机理研究" . | 北京工业大学学报 49 . 1 (2023) : 1-10 . |
| APA | 孙铁伟 , 王民 , 高相胜 , 赵英杰 . 基于等温弹流润滑理论的滚珠丝杠副摩擦机理研究 . | 北京工业大学学报 , 2023 , 49 (1) , 1-10 . |
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Abstract ：
本发明提供一种铣刀磨损监测方法及装置，该方法包括：采集铣削加工过程中机床主轴端的振动信号；选取有效铣削状态下的有效振动信号进行EEMD分解，以得到有效振动信号对应的多个IMF分量；根据各本征模态函数分量分别与有效振动信号的互信息系数和能量权重从多个IMF分量中选出主模态振动；计算所述主模态振动的瞬时幅值函数和瞬时频率函数；根据所述瞬时幅值函数和瞬时频率函数计算振动阻尼比；根据主轴旋转周期，选择旋转周期内对应的所述振动阻尼比计算一个旋转周期的平均阻尼比；以所述平均阻尼比作为铣刀磨损指标监测铣刀磨损过程，从而实现了对铣刀磨损过程有效地监测。
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| GB/T 7714 | 王民 , 杨斌 , 昝涛 et al. 铣刀磨损监测方法及装置 : CN202210292147.7[P]. | 2022-03-23 . |
| MLA | 王民 et al. "铣刀磨损监测方法及装置" : CN202210292147.7. | 2022-03-23 . |
| APA | 王民 , 杨斌 , 昝涛 , 高相胜 , 高鹏 . 铣刀磨损监测方法及装置 : CN202210292147.7. | 2022-03-23 . |
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Abstract ：
本实用新型提供了一种多关节臂超声振动脊柱钙化组织介入手术去除装置，包括沿前后方向固定连接的超声振动骨刀模块和多关节柔性臂模块；多关节柔性臂模块可弯曲运动地带动超声振动骨刀模块弯曲切割脊柱钙化骨组织。本实用新型切除效果好，效率高，出血少，能够对位置偏僻、结构复杂的脊柱钙化骨组织进行弯曲切削，减少手术风险、降低手术难度。
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| GB/T 7714 | 袁有 , 高鹏 , 金一丹 et al. 多关节臂超声振动脊柱钙化组织介入手术去除装置 : CN202223178042.3[P]. | 2022-11-25 . |
| MLA | 袁有 et al. "多关节臂超声振动脊柱钙化组织介入手术去除装置" : CN202223178042.3. | 2022-11-25 . |
| APA | 袁有 , 高鹏 , 金一丹 , 高瑞杰 , 王民 , 高相胜 et al. 多关节臂超声振动脊柱钙化组织介入手术去除装置 : CN202223178042.3. | 2022-11-25 . |
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Abstract ：
Bearing fault diagnosis that utilizes motor current has shown great potential for industrial application. For estimating fault sizes, this paper develop an electromechanical-magnetic coupling computational model of induction motor (IM) based on modified winding function approach (MWFA) in order to extract the fault-excited harmonic components and amplitudes in stator current. A new evaluating indicator FHD (Fault-excited Harmonic Distortion) is then proposed to describe the specific relation between fault sizes and severity of fault-excited harmonic distortion. The statistical results show that there is a fixed functional relation curve between FHD and fault sizes in different IM. Finally, an experimental IM with a known size built-in faulted bearing is investigated. The 1 mm artificial damage on outer raceway is recognized by calculating FHD (0.5636 in average) value and comparing with the simulated relation curve. The results validate the accuracy and robustness of the proposed approach in fault size estimation. © 2020
Keyword ：
Electric fault currents Electric fault currents Harmonic analysis Harmonic analysis Induction motors Induction motors Stators Stators Ball bearings Ball bearings Harmonic distortion Harmonic distortion
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| GB/T 7714 | Wang, Chen , Wang, Min , Yang, Bin et al. A novel methodology for fault size estimation of ball bearings using stator current signal [J]. | Measurement: Journal of the International Measurement Confederation , 2021 , 171 . |
| MLA | Wang, Chen et al. "A novel methodology for fault size estimation of ball bearings using stator current signal" . | Measurement: Journal of the International Measurement Confederation 171 (2021) . |
| APA | Wang, Chen , Wang, Min , Yang, Bin , Song, Kaiyu , Zhang, Yiling , Liu, Liming . A novel methodology for fault size estimation of ball bearings using stator current signal . | Measurement: Journal of the International Measurement Confederation , 2021 , 171 . |
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Abstract ：
The overall dynamic mechanical behavior of a double-scale discontinuous rock mass with a nonlinear deformational macrojoint was investigated. A method of combining the split three characteristic lines with the piecewise linear displacement discontinuity model (DDM) was proposed. The method was applied to investigate the transmission coefficient of P-wave propagation normally through a double-scale discontinuous rock mass with a nonlinear deformational macrojoint. The results were verified by comparison with the results of P-wave propagation normally through a double-scale discontinuous rock mass with a linear deformational macrojoint. The results showed that for a small amplitude stress wave, the nonlinear deformational macrojoint can be simplified as a linear deformational form to study the stress wave propagation, whereas for a large amplitude stress wave, the effects of the nonlinear deformational behavior of the macrojoint must be considered. The difference of the effects of nonlinear and linear deformational macrojoints on large amplitude stress wave propagation can be overlooked in the low-frequency or high-frequency regions. In addition, when the incident stress wave amplitude and initial macrojoint stiffness are sufficiently large, the effects of the nonlinear deformational macrojoint on stress wave propagation can be overlooked, and the effects of microdefects must be considered. The influence degree of microdefects on the stress wave propagation increases with the increase of incident stress wave frequency. © 2020, Springer-Verlag GmbH Austria, part of Springer Nature.
Keyword ：
Piecewise linear techniques Piecewise linear techniques Seismic waves Seismic waves Wave propagation Wave propagation Rocks Rocks Rock mechanics Rock mechanics
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| GB/T 7714 | Fan, L.F. , Wang, M. , Wu, Z.J. . Effect of Nonlinear Deformational Macrojoint on Stress Wave Propagation Through a Double-Scale Discontinuous Rock Mass [J]. | Rock Mechanics and Rock Engineering , 2021 , 54 (3) : 1077-1090 . |
| MLA | Fan, L.F. et al. "Effect of Nonlinear Deformational Macrojoint on Stress Wave Propagation Through a Double-Scale Discontinuous Rock Mass" . | Rock Mechanics and Rock Engineering 54 . 3 (2021) : 1077-1090 . |
| APA | Fan, L.F. , Wang, M. , Wu, Z.J. . Effect of Nonlinear Deformational Macrojoint on Stress Wave Propagation Through a Double-Scale Discontinuous Rock Mass . | Rock Mechanics and Rock Engineering , 2021 , 54 (3) , 1077-1090 . |
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Abstract ：
A dual-mesh three characteristic lines method was proposed for stress wave propagation through a microdefected rock mass containing a thin-layer filled macrojoint. The dual-mesh three characteristic lines are composed of five basic elements that are used to calculate stress wave propagation at the boundary and the interior of the microdefected rock mass and the left side, interior and right side of the filled macrojoint. The results of the present study were compared with that of available analytical results that do not consider microdefects and do not consider microdefects and macrojoint thickness. The results show that the proposed method can be used to efficiently investigate the effect of microdefects and filled macrojoints on wave propagation. The results also show that the viscosity coefficient in the equivalent viscoelastic model of the microdefected rock mass, the viscosity coefficient in the equivalent viscoelastic model of the filled macrojoint and the thickness of the filled macrojoint have significant effects on stress wave attenuation. The transmission coefficient initially decreases and then increases as the viscosity coefficient in the equivalent viscoelastic model of the microdefected rock mass increases. The transmission coefficient increases and then tends to flatten as the viscosity coefficient in the equivalent viscoelastic model of the filled macrojoint increases. The transmission coefficient decreases as the thickness of the filled macrojoint increases.
Keyword ：
Dual-mesh three characteristic lines method Dual-mesh three characteristic lines method Rock mass Rock mass Microdefect Microdefect Stress wave propagation Stress wave propagation Filled macrojoint Filled macrojoint
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| GB/T 7714 | Fan, L. F. , Wang, M. , Du, X. L. . Dual-Mesh Three Characteristic Lines Method for Stress Wave Propagation Through a Microdefected Rock Mass with a Thin-Layer Filled Macrojoint [J]. | ROCK MECHANICS AND ROCK ENGINEERING , 2021 , 54 (12) : 6621-6632 . |
| MLA | Fan, L. F. et al. "Dual-Mesh Three Characteristic Lines Method for Stress Wave Propagation Through a Microdefected Rock Mass with a Thin-Layer Filled Macrojoint" . | ROCK MECHANICS AND ROCK ENGINEERING 54 . 12 (2021) : 6621-6632 . |
| APA | Fan, L. F. , Wang, M. , Du, X. L. . Dual-Mesh Three Characteristic Lines Method for Stress Wave Propagation Through a Microdefected Rock Mass with a Thin-Layer Filled Macrojoint . | ROCK MECHANICS AND ROCK ENGINEERING , 2021 , 54 (12) , 6621-6632 . |
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Abstract ：
A new analytical method for the modeling of the thermal contact resistance of ball screws considering the load distribution of balls is proposed in this research. The load on balls is analyzed by the force analysis of ball screws, and then, the thermal contact resistance is obtained by the minimum excess principle and Majumdar-Bhushan (MB) fractal theory. The proposed method is validated by experimental results. The comparison with experimental and former results indicates that it is an effective method to evaluate the thermal contact resistance of ball screws. On that basis, effects of axial load, axial pretension, and geometry error of balls are discussed. It is concluded that the thermal contact resistance of ball screws increases along with axial load increase. The load on balls all decreases with axial pretension increase, and the thermal contact resistance of ball screws decreases with the axial pretension increase as well. When the axial load is applied on the nut in an axial-pretension ball screw, the load distribution in Nut A or B becomes less homogenized when the nut moves from nut position parameter xi = 0 to 1. When the nut moves to xi = 0.25, the thermal contact resistance will reach a minimum value, and it gets a maximum value at the nut position xi = 1. The interval range of load and thermal contact resistance are obtained via uncertain analysis. It is concluded that the geometry error has much greater effects on the balls far away from the spacer.
Keyword ：
thermal contact resistance thermal contact resistance axial load axial load axial pretension axial pretension ball screw ball screw geometry error geometry error load distribution load distribution
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| GB/T 7714 | Gao, Xiangsheng , Ma, Jiqian , Li, Qi et al. Modeling of Thermal Contact Resistance of Ball Screws Considering the Load Distribution of Balls [J]. | JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS , 2021 , 13 (4) . |
| MLA | Gao, Xiangsheng et al. "Modeling of Thermal Contact Resistance of Ball Screws Considering the Load Distribution of Balls" . | JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS 13 . 4 (2021) . |
| APA | Gao, Xiangsheng , Ma, Jiqian , Li, Qi , Wang, Min , Zan, Tao . Modeling of Thermal Contact Resistance of Ball Screws Considering the Load Distribution of Balls . | JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS , 2021 , 13 (4) . |
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Abstract ：
It is well-known that second-order optimizer can accelerate the training of deep neural networks, however, the huge computation cost of second-order optimization makes it impractical to apply in real practice. In order to reduce the cost, many methods have been proposed to approximate a second-order matrix. Inspired by KFAC, we propose a novel Trace-based Hardware-driven layer-ORiented Natural Gradient Descent Computation method, called THOR, to make the second-order optimization applicable in the real application models. Specifically, we gradually increase the update interval and use the matrix trace to determine which blocks of Fisher Information Matrix (FIM) need to be updated. Moreover, by resorting the power of hardware, we have designed a hardware-driven approximation method for computing FIM to achieve better performance. To demonstrate the effectiveness of THOR, we have conducted extensive experiments. The results show that training ResNet-50 on ImageNet with THOR only takes 66.7 minutes to achieve a top-1 accuracy of 75.9 % under an 8 Ascend 910 environment with MindSpore, a new deep learning computing framework. Moreover, with more computational resources, THOR can only takes 2.7 minutes to 75.9 % with 256 Ascend 910.
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| GB/T 7714 | Chen, Mengyun , Gao, Kaixin , Liu, Xiaolei et al. THOR, Trace-Based Hardware-Driven Layer-Oriented Natural Gradient Descent Computation [C] . 2021 : 7046-7054 . |
| MLA | Chen, Mengyun et al. "THOR, Trace-Based Hardware-Driven Layer-Oriented Natural Gradient Descent Computation" . (2021) : 7046-7054 . |
| APA | Chen, Mengyun , Gao, Kaixin , Liu, Xiaolei , Wang, Zidong , Ni, Ningxi , Zhang, Qian et al. THOR, Trace-Based Hardware-Driven Layer-Oriented Natural Gradient Descent Computation . (2021) : 7046-7054 . |
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Abstract ：
With the development of space technology, the large scale space deployable antennas gradually become one of the key research themes of research. The basic requirements for large scale satellite antennas are the characteristics of light in weight and high in profile accuracy. The low-frequency and large-amplitude vibration of the large scale antennas is easily excited when working in an environment with zero gravity. In order to suppress the vibration of large scale deployable satellite antenna, a new type of damping mechanism with resetting capability is presented to improve the ability of vibration energy consumption and ensure the dynamic characteristics of the radial rib structure containing the presented profile accuracy of the antenna. The rod making up the deployment mechanism of the antennas is divided into two parts which connected by using the shape memory alloy (SMA) wires through guiding mechanism. Meanwhile, a metal rubber is fixed and pressed between two parts of the rod by SMA wires. The ability of the friction energy dissipation of the metal rubber is utilized to suppress the axial vibration of the rods. The super elasticity of the SMA wires is used to provide the restoring force for ensuring the dimensional stability of the rod. In this paper, the design principle of the axial self-resetting damping structure is introduced in detail. And, the dynamic characteristics of the radial rib structure containing the presented damping mechanism are investigated by using the software ANSYS. The simulation results show that the vibration amplitude of the radial rib of antennas has been reduced significantly. © Published under licence by IOP Publishing Ltd.
Keyword ：
Scales (weighing instruments) Scales (weighing instruments) Energy utilization Energy utilization Rubber Rubber Energy dissipation Energy dissipation Satellite antennas Satellite antennas Dynamics Dynamics Vibration control Vibration control Satellites Satellites Wire Wire Damping Damping Shape-memory alloy Shape-memory alloy
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| GB/T 7714 | Wang, Min , Liu, Jiaxing , Liu, Qinda et al. Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna [C] . 2021 . |
| MLA | Wang, Min et al. "Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna" . (2021) . |
| APA | Wang, Min , Liu, Jiaxing , Liu, Qinda , Zhao, Tingting , Zhang, Yunfei . Research on Damping Mechanism with Resetting Capability for Axial Vibration Control of Satellite Antenna . (2021) . |
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Abstract ：
Second-order optimization methods have the ability to accelerate convergence by modifying the gradient through the curvature matrix. There have been many attempts to use second-order optimization methods for training deep neural networks. In this work, inspired by diagonal approximations and factored approximations such as Kronecker-factored Approximate Curvature (KFAC), we propose a new approximation to the Fisher information matrix (FIM) called Trace-restricted Kronecker-factored Approximate Curvature (TKFAC), which can hold the certain trace relationship between the exact and the approximate FIM. In TKFAC, we decompose each block of the approximate FIM as a Kronecker product of two smaller matrices and scaled by a coefficient related to trace. We theoretically analyze TKFAC's approximation error and give an upper bound of it. We also propose a new damping technique for TKFAC on convolutional neural networks to maintain the superiority of second-order optimization methods during training. Experiments show that our method has better performance compared with several state-of-the-art algorithms on some deep network architectures.
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| GB/T 7714 | Gao, Kaixin , Liu, Xiaolei , Huang, Zhenghai et al. A Trace-restricted Kronecker-factored Approximation to Natural Gradient [C] . 2021 : 7519-7527 . |
| MLA | Gao, Kaixin et al. "A Trace-restricted Kronecker-factored Approximation to Natural Gradient" . (2021) : 7519-7527 . |
| APA | Gao, Kaixin , Liu, Xiaolei , Huang, Zhenghai , Wang, Min , Wang, Zidong , Xu, Dachuan et al. A Trace-restricted Kronecker-factored Approximation to Natural Gradient . (2021) : 7519-7527 . |
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