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A signature extracting method for inductive online oil debris sensors based noise-assisted local mean decomposition and kurtosis mode selection

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A signature extracting method for inductive online oil debri...

Studies of antioxidant performance of amine additives in lubricating oil using 3D-QSAR

第35届中国过程控制会议

作者： Ning Wang Minglv Jin Jinglun Xu Ye Zheng Baiyu Zhu Yunqi Cao Pingjie Huang State Key laboratory of Industrial Control Technology College of Control Science and EngineeringZhejiang University

The inductive wear debris sensor is extensively utilized for online measurement of metal particles in lubricating oil, enabling the assessment of the operational state of rotating machinery. Given the harsh working environment of the debris sensor, particularly the susceptibility of small-sized debris signals to be overwhelmed by background noise, the challenge lies in effectively processing the signal to eliminate noise and extract debris signatures. A noise-assisted local mean decomposition(LMD) method that combining kurtosis mode selection and mode cell thresholding denoising is investigated. This approach selects modal components containing characteristic debris signals based on kurtosis, mitigates mode mixing by incorporating complementary noise, and ultimately performs noise reduction and signal reconstruction through mode cell thresholding. Through experimental analysis of both simulated signals and actual signals, the proposed method demonstrates its effectiveness in detecting weak debris signals amidst strong background noise, providing critical support for subsequent feature processing.

关键词： oil debris sensor Local mean decomposition kurtosis noise assistance signal reconstruction

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Science China(Technological Sciences) 2017年第2期60卷 299-305页

作者： ZHAN ShengPeng DUAN HaiTao HUA Meng XU HaiPing SHANG HongFei JIN YongLiang JIA Dan TU JieSong LI Jian State Key laboratory of Special Surface Protection materials and Application Technology Wuhan Research Institute of Materials ProtectionWuhan 430030China MBE Department City University of Hong KongKowloonHong KongChina Xi'an Precision Machinery Research Institute Xi'an 710075China State Key laboratory of Tribology Tsinghua UniversityBeijing100084China

Available model of 3D-quantitative structure-activity relationship (3D-QSAR, the method of TopomerCoMFA) has been used to establish relationship between antioxidant performances of lubricating oil (trimethylolpropane trioleate, TMPTO) with 15 kinds of amine additives and its molecular structure. Correlation coefficient of the cross-validation (include internal q2 and external qpred 2 ) and conventional correlation coefficient showed the model to be both stable and good predictive. The electron-donating group and larger steric effects group are adopted at the para-position or meta-position of amido on the benzene ring, and suitably decreasing the branch chain near the para-position, these indicate that the antioxidant performance of amine additives can be enhanced. The results not only can help us understanding the rule of antioxidant performance, but also providing guidance(s) to predict antioxidant performance of existing amine additives and to design or modify new amine additives in lubricating oil.

关键词： QSAR amine additive TopomerCoMFA antioxidant performance lubrication

Microstructure and properties of HVOF sprayed Ni-based submicron WS_2/CaF_2 self-lubricating composite coating

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中国有色金属学会会刊：英文版 2009年第1期19卷 85-92页

作者：章小峰张祥林王爱华黄早文 State Key laboratory of Material Processing and Die and Mould Technology Huazhong University of Science and Technology School of materials Science and Engineering Huazhong University of Science and Technology

Ni-based submicron WS2/CaF2 self-lubricating composite coatings were produced on carbon steel substrate by high velocity oxygen fuel(HVOF) spray processing, and the microstructure and mechanical properties of the coatings were investigated. Non-uniform microstructure characterized by some pores and microcracks is observed in the produced composite coatings, which leads to low microhardness value, low adhesive strength and low frictional coefficient. For Ni45-5%CaF2-10%WS2 (mass fraction) and Ni45-10%CaF2-5%WS2 (mass fraction) coatings, under the test condition of load 40 N and speed 2 m/s, the friction coefficients obtained at room temperature are in the range of 0.35-0.48 and 0.31-0.41, respectively. The friction coefficients of two kinds of coatings increase to 0.4-0.63 and 0.35-0.46, respectively, at the test speed of 1 m/s. And the Ni45-10%CaF2-5%WS2 coating presents the minimum friction coefficient of 0.32-0.38 and good anti-wear properties at 400 ℃.

关键词：超音速火焰喷涂过程颗粒行为数值模拟钨粉金属粉末

Sliding Wear of the Hybrid Kevlar/PTFE Fabric Reinforced Phenolic Composite Filled with Nano-titania

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Chinese Journal of Mechanical Engineering 2011年第1期24卷 154-159页

作者： YANG Yulin HUANG Shijun ZU Dalei ZHANG Ruijun QI Xiaowen Key laboratory of Fundamental Science of Mechanical Structure and Material Science under Extreme Condition for National Defence Yanshan University Qinhuangdao 066004 China State Key laboratory of Metastable materials Science and Technology Yanshan University Qinhuangdao 066004 China

The Kevlar/polytetrafluroethylene（Kevlar/PTFE） fabric composite can be used as a self-lubricating liner of the self-lubricating *** types of nano-particles can improve the tribological performance of the polymer-based ***,up to now,published work on the effect of nano-particles on the tribological performance of the fabric composite which can be used as a self-lubricating liner is quite ***,for the purpose of exploring a way to significantly improve the tribological performance of the fabric composite,the tribological performance of the Kevlar/PTFE fabric composite filled with nano-titania is evaluated by using the block-on-ring wear *** scanning electron microscopy is utilized to observe the morphologies of worn surfaces of the fabric composites and the *** tensile properties of the composites are evaluated on the universal material testing *** test results show that the addition of nano-titania at a proper mass fraction of the matrix resin improves the wear resistance and the tensile strength,decreases the friction coefficient,and makes the wear volume of the composite reach a relative steady state more quickly;plastic deformation and microcutting are important for the wear of the fabric composite;a lubricating layer is formed on the worn surface of the composite during sliding,and the lubricating layer is critical for the tribological performance of the composite;the formation and properties of the lubricating layer are influenced by the nano-titania *** proposed study on the effect of nano-titania on the tribological performance of the Kevlar/PTFE fabric composite,especially on the evolution of the worn surface of the composite,provides the basis for further understanding of the influence mechanism of the nano-particles on the tribological performance of the composite and explores a method of improving the tribological performance of the composite.

关键词： hybrid Kevlar/PTFE fabric composite self-lubricating liner nano-titania friction and wear lubricating layer

Tribological evaluation of surface modified H13 tool steel in warm forming of Ti–6Al–4V titanium alloy sheet

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Chinese Journal of Aeronautics 2014年第4期27卷 1002-1009页

作者： Wang Dan Li Heng Yang He Ma Jun Li Guangjun State Key laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical University AVIC Cheng Du Aircraft Industry (Group) Co. Ltd

The H13 hot-working tool steel is widely used as die material in the warm forming of Ti–6Al–4V titanium alloy sheet. However, under the heating condition, severe friction and lubricating conditions between the H13 tools and Ti–6Al–4V titanium alloy sheet would cause difficulty in guaranteeing forming quality. Surface modification may be used to control the level of friction force, reduce the friction wear and extend the service life of dies. In this paper, four surface modification methods（chromium plating, TiAlN coating, surface polishing and nitriding treatment）were applied to the H13 surfaces. Taking the coefficient of friction（CoF） and the wear degree as evaluation indicators, the high-temperature tribological behavior of the surface modified H13 steel was experimentally investigated under different tribological conditions. The results of this study indicate that the tribological properties of the TiAlN coating under dry friction condition are better than the others for a wide range of temperature（from room temperature to 500 C）, while there is little difference of tribological properties between different surface modifications under graphite lubricated condition, and the variation law of CoF with temperature under graphite lubricated is opposite to that under the dry friction.

关键词： Coefficient of friction H13 Surface modification Ti-6Al-4V Tools Warm forming Wear

Microstructures, mechanical properties, and grease-lubricated sliding wear behavior of Cu–15Ni–8Sn–0.8Nb alloy with high strength and toughness

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Friction 2021年第5期9卷 1061-1076页

作者： Jinjuan CHENG Mincong MAO Xueping GAN Qian LEI Zhou LI Kechao ZHOU State Key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of materials Science and Engineering Central South UniversityChangsha 410083China

Alloys used as bearings in aircraft landing gear are required to reduce friction and wear as well as improve the load‐carrying capability due to the increased aircraft ***–15Ni–8Sn–0.8Nb alloy is well known for possessing good mechanical and wear properties that satisfy such *** this study,the microstructure,mechanical properties,and grease‐lubricated sliding wear behavior of Cu–15Ni–8Sn–0.8Nb alloy with 0.8 wt%Nb are *** nanoscale NbNi3 and NbNi2Sn compounds can strengthen the alloy through the Orowan strengthening mechanism.A Stribeck‐like curve is plotted to illustrate the relationship among friction coefficient,normal load,and sliding velocity and to analyze the grease‐lubricated *** wear rate increases with normal load and decreases with sliding velocity,except at 2.58 m/s.A wear mechanism map has been developed to exhibit the dominant wear mechanisms under various friction *** the normal load is 700 N and the sliding velocity is 2.58 m/s,a chemical reaction between the lubricating grease and friction pairs occurs,resulting in the failure of lubricating grease and an increase in wear.

关键词： Cu–15Ni–8Sn–0.8Nb alloy microstructure mechanical properties grease‐lubricated wear behavior

Wear map for sliding wear behavior of Cu-15Ni-8Sn alloy against bearing steel under oil-lubricated condition

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Journal of Central South University 2020年第2期27卷 311-324页

作者： CHENG Jin-juan GAN Xue-ping LI Zhou LEI Qian ZHOU Ke-chao State Key laboratory of Powder Metallurgy Central South UniversityChangsha 410083China School of materials Science and Engineering Central South UniversityChangsha 410083China

Wear behaviors of a peak-aged Cu-15Ni-8Sn alloy fabricated by powder metallurgy were *** results indicated that the friction coefficients and the wear rates of Cu-15Ni-8Sn alloy within a normal load range of 50−700 N and a sliding speed range of 0.05−2.58 m/s were less than 0.14 and 2.8×10−6 mm3/mm,***-like curve and wear map were developed to describe the oil-lubrication mechanism and wear *** equation of the dividing line between zones of safe and unsafe wear life was *** oil was squeezed into micro-cracks under severe wear *** addition,the lubricating oil reacted with Cu-15Ni-8Sn alloy to generate the corresponding sulfides,which hindered the repair of micro-cracks,promoted cracks growth,and led to *** work has established guidelines for the application of the Cu-15Ni-8Sn alloy under oil-lubricated conditions through developing wear map.

关键词： Cu-15Ni-8Sn alloy oil lubrication wear behavior wear map

Effects of Friction Heat on the Tribological Properties of the Woven Self-lubricating Liner

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Chinese Journal of Mechanical Engineering 2009年第6期22卷 918-924页

作者： YANG Yulin ZU Dalei ZHANG Ruijun QI Xiaowen Key laboratory of Fundamental Science of Mechanical Structure and Material Science under Extreme Condition for National Defence Yanshan University Qinhuangdao 066004 China State Key laboratory of Metastable materials Science and Technology. Yanskan Universiry Qinhuangdao 066004 China

In the dry-sliding process of the woven self-lubricating liner which is used in the self-lubricating spherical plain bearing, the friction heat plays an important role in the tribological performances of the liner. It has important value to study on the relationship between tribological performances of the liner and the friction heat. Unforttmately, up to now, published work on this relationship is quite scarce. Therefore, the effect of friction heat on the tribological performances of the liner was investigated in the present work. The tribological behaviors of the liner were evaluated by using the high temperature end surface wear tester. Scanning electron microscopy （SEM） was utilized to examine the morphologies of worn surfaces of the liner and study the failure modes. Differential scanning calorimetry （DSC） measurement and X-ray diffraction （XRD） analysis were performed to study the behaviors of the wear debris. The temperature rise on the worn surface was calculated according to classical models. SEM observation shows that the dominating wear mechanism for the liner is mainly affected by friction shear force, contact pressure and friction heat. Higher fusion heat for the wear debris than that for the pure polytetrafluroethylene （PTFE） indicates that the PTFE is the main portion of the wear debris, and, the PTFE in the wear debris shows a higher crystallisation degree owing to the effects of friction shear force and the friction heat. Combining the calculated temperature rise results with the wear rate of the liner, it can be concluded that the effects of temperature rise o n the tribological performances of the liner become more obvious when the temperature rise exceeds the glass transition temperature （Tg） of the PTFE. The wear resistance of the liner deteriorates dramatically when the temperature rise approaches to the melting point （Ton） of the PTFE. The tribological performances of the liner can be improved when the temperature rise exceeds Tg but is far l

关键词： woven fabric self-lubricating liner friction and wear friction heat differential scanning calorimetry thermal analysis transfer film

Study of Harmful Vaginal Practices of Women in the Municipality of Ouagadougou, Burkina Faso

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Health 2024年第5期16卷 425-438页

作者： Daniel Dori Ramata Porgo Hyacinthe Zamané Nicolas Méda Rasmané Semdé Drug Development laboratory African Center of Excellence for Training Research and Expertise in Pharmaceutical Sciences (CEA-CFOREM) Sciences and Health Doctoral School Training and Research Unit in Health Sciences Joseph Ki-Zerbo University Ouagadougou Burkina Faso Charles De Gaulle University Children’ s Hospital (CHUP-CDG) Ouagadougou Burkina Faso Public Health laboratory Sciences and Health Doctoral School Joseph Ki-Zerbo University Ouagadougou Burkina Faso Mother and Child laboratory Sciences and Health Doctoral School Joseph Ki-Zerbo University Ouagadougou Burkina Faso

Introduction: Vaginal practices include washing, altering, cutting, cleaning, enhancing, drying, tightening, lubricating, or loosening of the vagina, labia, clitoris, or hymen. This study aimed to investigate the different vaginal practices of women using non-pharmaceutical products. Methodology: This was a cross-sectional study with descriptive and analytical purposes that took place from January 15 to April 23, 2023, in the four largest markets in the municipality of Ouagadougou. This was performed using the data collection sheet in the KoboCollect application. Epi info 7.***.5.0. software was used for data analysis. For the analysis of associated factors, a p-value Results: In total, 977 women were surveyed. Among them, 43.19% underwent vaginal procedures using non-pharmaceutical products. The female practitioners were 34.34 ± 7.44 years old. The products used included plants, mineral substances, ointments, tablets, and solutions. Among the practicing women, 40.99% were looking for vaginal tightening. The main purpose was to maintain their partners (45.97%). Three-point thirty-two percent (3.32%) of the women who underwent vaginal procedures had reported adverse events. Conclusion: Raising awareness of the consequences of vaginal practices and encouraging women to go to a health center for any gynecological problem could significantly reduce the prevalence of vaginal practices.

关键词： Vaginal Practices Women Adverse Events Products