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基于状态划分和集成学习的轴承剩余使用寿命预测模型

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机电工程 2024年第8期41卷 1423-1430页

作者：胡志辉王绪光王贡献张腾李帅琦武汉理工大学交通与物流工程学院湖北武汉430063

针对滚动轴承剩余使用寿命(RUL)预测退化起始时间(DST)难以确定,以及单一寿命预测模型精度比较低的问题,提出了一种基于状态划分和集成学习模型的滚动轴承RUL预测方法。首先,提取了轴承振动信号的特征,利用滑动窗口不断更新3σ准则预警... 详细信息

针对滚动轴承剩余使用寿命(RUL)预测退化起始时间(DST)难以确定,以及单一寿命预测模型精度比较低的问题,提出了一种基于状态划分和集成学习模型的滚动轴承RUL预测方法。首先,提取了轴承振动信号的特征,利用滑动窗口不断更新3σ准则预警范围,结合连续触发机制自适应确定DST;然后,采用具有自适应噪声的完全集成经验模态分解(CEEMDAN)对退化阶段信号序列进行了自适应分解;最后,构建了集成学习模型,考虑分量的不同特性进行了多步滚动预测,融合预测结果得到了轴承RUL,采用滚动轴承XJTU-SY公开数据集进行了试验验证。研究结果表明:与基于长短时记忆神经网络(LSTM)、反向传播神经网络(BPNN)的预测方法相比,该方法预测结果的平均绝对误差分别降低了11.7%以及5.6%,相对均方根误差分别降低了12.2%以及10.7%,验证了该方法在轴承RUL预测中的有效性和优越性。

关键词：滚动轴承剩余使用寿命退化起始时间自适应DST状态划分集成学习模型退化特征提取具有自适应噪声的完全集成经验模态分解长短时记忆神经网络

THEORY AND EXPERIMENT ON THE VISCOUS HEATING OF FLUID DAMPER UNDER SHOCK ENVIRONMENT

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Chinese Journal of Mechanical Engineering 2008年第3期21卷 66-71页

作者： CHU Deying ZHANG Zhiyi wang gongxian HUA Hongxing wang Yu State Key Laboratory of Vibration Shock and Noise Shanghai Jiaotong University Shanghai 200240 China Chinese Navy Warship Research Center Beijing 100037 China

A specially designed fluid damper used as negative shock pulse generator in the shock resistance test system to dissipate the shock input energy in transient time duration is presented. The theoretical modeling based on the three-dimensional equation of heat transfer through a fluid element is created to predict the viscous heating in the fluid damper under shock conditions. A comprehensive experimental program that investigates the problem of viscous heating in the fluid damper under different shock conditions is conducted on the shock test machine to validate the analytical expression. Temperature histories for the fluid within the damper at two locations, the annular-oriflce and the-end-of stroke of the damper, are recorded. The experimental results show that the theoretical model can offer a very dependable prediction for the temperature histories in the damper for increasing input velocity. The theoretical model and experimental data both clearly indicate that the viscous heating in the damper is directly related to the maximum shock velocity input and the pressure between the two sides of the piston head.

关键词： Fluid damper Negative shock pulse generator Viscous heating Shock conditions

ANALYSIS AND SIMULATION ON THE MECHANISM OF A NOVEL DUAL-WAVE SHOCK TEST MACHINE

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Chinese Journal of Mechanical Engineering 2008年第1期21卷 94-100页

作者： wang gongxian ZHANG Zhiyi CHU Deying SHEN Rongying Institute of Vibration Shock and Noise Shanghai Jiaotong University Shanghai 200240 China School of Logistics Engineering Wuhan University of Technology Wuhan 430063 China

For qualifying the anti-shock performance of shipboard equipments and simulating actual underwater explosion environments, a novel dual-wave shock test machine is proposed to increase testing capability of shock test machines as well as to meet certain shock testing specification. The machine can generate a double-pulse acceleration shock for test articles according to specification defined in BV043/85. On the basis of the impact theory, a nonlinear dynamic model of the hydraulically-actuated test machine is established with thorough analysis on its mechanism which involves conversion of gas potential energy and dissipation of kinetic energy. Simulation results have demonstrated that the machine can produce a double-pulse acceleration shock in the time domain or a desired shock response spectrum in the frequency domain, which sets a theoretical base for the construction of the proposed machine.

关键词： Shock test machine Underwater explosion Velocity generator Pulse generator

NUMERICAL MODELING OF MULTI-CYLINDER ELECTRO-HYDRAULIC SYSTEM AND CONTROLLER DESIGN FOR SHOCK TEST MACHINE

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Chinese Journal of Mechanical Engineering 2007年第2期20卷 109-114页

作者： CHU Deying ZHANG Zhiyi wang gongxian HUA Hongxing State Key Laboratory of Vibration Shock and Noise Shanghai Jiaotong University Shanghai 200240 China

A high fidelity dynamic model of a high-energy hydraulically-actuated shock test machine for heavy weight devices is presented to satisfy the newly-built shock resistance standard and simulate the actual underwater explosion environments in laboratory as well as increase the testing capability of shock test machine. In order to produce the required negative shock pulse in the given time duration, four hydraulic actuators are utilized. The model is then used to formulate an advanced feedforward controller for the system to produce the required negative waveform and to address the motion synchronization of the four cylinders. The model provides a safe and easily controllable way to perform a ＂virtual testing＂ before starting potentially destructive tests on specimen and to predict performance of the system. Simulation results have demonstrated the effectiveness of the controller.

关键词： Shock test machine Negative shock pulse Actuator redundancy Feedforward controller Virtual testing

Nonlinear Dynamics Seismic Response of Container Crane Based on Contact Friction Theory

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仪器仪表学报 2013年第S1期34卷 147-152页

作者： wang Dong wang gongxian Xiong Yeping Li Zhe School of Logistic Engineering Wuhan University of Technology Faculty of Engineering and the Environment University of Southampton

To evaluate the dynamic behavior of a container crane under seismic loads accurately,the contact state between the wheels and the rails or the ground that significantly affect the seismic response of the structure must be considered *** paper has proposed a modeling method based on the theory of contact and friction for simulating the nonlinear seismic response of large and flexible structure of a jumbo movable container crane,including the contact problem regarding the wheels attached to the bottom of its legs and the rails on which they *** models are used to perform extensive dynamic time-history analysis in order to find out their nonlinear dynamic behavior under various excitation *** is found that the presented numerical modeling method simulates the nonlinear seismic response of a container crane quite ***,it can verify and expand our understanding of the seismic behaviors by evaluating response performance for the large seaport cranes.

关键词： container crane seismic response fem analysis contact and friction model

2023年春季北方蚕区家蚕新品种实验室鉴定(安康点)成绩分析报告

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北方蚕业 2024年第2期45卷 36-39页

作者：刘晓李琴陈佳王功献陈正余安康市蚕桑产业发展中心陕西安康725000

2023年春季,安康市蚕桑产业发展中心蚕桑研究所对苏州大学提供的家蚕彩色茧新杂交组合“313×410(正反交)”进行全龄桑叶育对比试验;对山东农业大学提供的家蚕品种“优食一号(正反)”进行1—3龄人工饲料育、4—5龄桑叶育对比试验。与菁... 详细信息

2023年春季,安康市蚕桑产业发展中心蚕桑研究所对苏州大学提供的家蚕彩色茧新杂交组合“313×410(正反交)”进行全龄桑叶育对比试验;对山东农业大学提供的家蚕品种“优食一号(正反)”进行1—3龄人工饲料育、4—5龄桑叶育对比试验。与菁松×皓月全龄桑叶育相比,313×410(正反交)和优食一号(正反交)的死笼率低,万蚕收茧量、万蚕茧层量低,普通茧重量百分率高,上车率高,解舒率低,解舒光折大,万米吊糙次数多。

关键词：桑蚕品种实验室鉴定安康点

Epigenetic reprogramming of embryos derived from sperm frozen at-20℃

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Science China(Life Sciences) 2012年第4期55卷 349-357页

作者： CHAO ShiBin LI JianChun JIN XuanJin TANG HaiXun wang gongxian GAO GuoLan Center of Reproductive Medicine the First Affiliated Hospital of Nanchang University Nanchang 330006 China Department of Obstetrics and Gynecology Aviation General Hospital of China Beijing 100101 China

Cryopreservation of spermatozoa is a strategy that has been used to conserve the sperm of animal species and animal strains that are valuable for biomedical research. A simple method for preserving spermatozoa after application of intracytoplasmic sperm injection （ICSI） is much needed. It has been shown previously that spermatozoa frozen at -20~C can activate oocytes and support full-term embryo development. However, epigenetic reprogramming could be affected by the environment and by the in vitro manipulation of gametes. Here, we investigated embryo epigenetic reprogramming including DNA methylation and histone modification, in embryos derived from sperm preserved at -20~C without cryoprotectants. The results showed that alt- hough both fertilization and embryo developmental competence were decreased, the dynamic epigenetic reprogramming of embryos derived from frozen sperm was similar to the reprogramrning of embryos derived from fresh sperm. The results re- ported in this study indicate that sperm frozen without cryoprotectant is epigenetically safe for ICSI.

关键词： spermatozoa freezing ICSI epigenetic histone modification DNA methylation

国产单孔手术机器人在保留肾单位手术中的应用价值

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中华医学杂志 2024年第35期104卷 3323-3327页

作者：黄庆波李智彭程郭宏骞刘光香王行环王共先李小航徐俊楠王保军张旭马鑫解放军总医院泌尿外科医学部北京100853 南京大学医学院附属鼓楼医院泌尿外科南京210008 武汉大学中南医院泌尿外科武汉430000 南昌大学第一附属医院泌尿外科南昌330006

目的探讨国产精锋^(■)单孔手术机器人在保留肾单位手术中的应用价值。方法回顾性纳入2023年9至11月解放军总医院、南京大学医学院附属鼓楼医院、武汉大学中南医院以及南昌大学第一附属医院应用国产精锋^(■)机器人单孔腹腔镜行保留肾... 详细信息

目的探讨国产精锋^(■)单孔手术机器人在保留肾单位手术中的应用价值。方法回顾性纳入2023年9至11月解放军总医院、南京大学医学院附属鼓楼医院、武汉大学中南医院以及南昌大学第一附属医院应用国产精锋^(■)机器人单孔腹腔镜行保留肾单位手术的肾肿瘤患者的临床资料。总结患者围手术期情况、病理学检查结果以及术后并发症等情况。结果共纳入12例患者,男8例,女4例,年龄26~75(56±16)岁;体质指数为(25.1±2.7)kg/m^(2),左、右侧肾脏病变各6例;手术途径经腹腔9例,经后腹腔3例。肿物最大径为(2.7±0.7)cm,热缺血时间[M(Q_(1),Q_(3))]为19(15,26)min,手术时间180(149,216)min,术中失血量50(28,100)ml,术后受试者疼痛视觉模拟评分为(2.9±1.5)分。术后病理恶性肾透明细胞癌9例,其中核分级1级、2级、3级均为3例,病理TNM分期8例为pT1aN0M0,1例为pT3aN0M0,切缘未见癌;良性肾血管平滑肌脂肪瘤3例。术后均未输血,未出现发热、漏尿和切口愈合不良等并发症。结论初步经验显示国产精锋^(■)单孔腹腔镜机器人在泌尿外科保留肾单位手术中具有良好的临床应用价值。

关键词：肾肿瘤微创性机器人手术单孔保留肾单位术

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滑坡防治方案的选择与优化

岩石力学与工程学报 2006年第Z2期25卷 3867-3873页

作者：王恭先中铁西北科学研究院有限公司甘肃兰州730000

在对滑坡性质的深入了解和治理方案的精心比选基础上,经过40余年预防和治理了数以百计的滑坡和高边坡变形,均取得成功。在此提出确定防治方案应考虑的4个因素和不同类型滑坡的治理方案(包括用桥梁和隧道绕避滑坡的方案及线路通过滑坡的... 详细信息

在对滑坡性质的深入了解和治理方案的精心比选基础上,经过40余年预防和治理了数以百计的滑坡和高边坡变形,均取得成功。在此提出确定防治方案应考虑的4个因素和不同类型滑坡的治理方案(包括用桥梁和隧道绕避滑坡的方案及线路通过滑坡的6种方案),可为预防高边坡和路堤填方引起的“工程滑坡”的处理方案提供参考。

关键词：边坡工程滑坡防治方案选择和优化