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Friction 2021年第1期9卷 61-74页

作者： Jiajia JIA Guangbin YANG Chunli zhang shengmao zhang Yujuan zhang Pingyu zhang Engineering Research Center for Nanomaterials Henan UniversityKaifeng 475004China Institute of Pharmacy Henan UniversityKaifeng 475004China

A magnetic ionic liquid(abridged as MIL)[C_(6)mim]_(5)[Dy(SCN)_(8)]was prepared and used as the magnetic lubricant of a steel-steel sliding *** tribological properties of the as-prepared MIL were evaluated with a commercially obtained magnetic fluid lubricant(abridged as MF;the mixture of dioctyl sebacate and Fe_(3)O_(4),denoted as DIOS-Fe_3O_4)as a *** lubrication mechanisms of the two types of magnetic lubricants were discussed in relation to worn surface analyses by SEM-EDS,XPS,and profilometry,as well as measurement of the electric contact resistance of the rubbed steel *** results revealed that the MIL exhibits better friction-reducing and antiwear performances than the as-received MF under varying test temperatures and *** is because the MIL participates in tribochemical reactions during the sliding process,and forms a boundary lubrication film composed of Dy_(2)O_(3),FeS,FeSO_(4),nitrogen-containing organics,and thioether on the rubbed disk surface,thereby reducing the friction and wear of the frictional ***,the MF is unable to form a lubricating film on the surface of the rubbed steel at 25°C,though it can form a boundary film consisting of Fe_(3)O_(4) and a small amount of organics under high ***,the excessive Fe_(3)O_(4) particulates that accumulate in the sliding zone may lead to enhanced abrasive wear of the sliding pair.

关键词： steel-steel sliding contact magnetic ionic liquid magnetic fluid lubricant tribological property lubrication mechanism

Self-dispersed molybdenum disulfide quantum dot/graphene crumpled ball as efficient high temperature lubricant additive

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Friction 2024年第8期12卷 1771-1784页

作者： Guiru DU Yujuan zhang Shuguang FAN Ningning SONG shengmao zhang Pingyu zhang Engineering Research Center for Nanomaterials Henan UniversityKaifeng 475004China

Inorganic nanoparticles have been proved as powerful lubricant additives at elevated ***,the tribological properties are inevitably impaired due to poor dispersion and insufficient high temperature resistance of organic matter modified ***,we prepare a self-dispersed molybdenum disulfide quantum dot/graphene crumpled ball(MGCB)comprising molybdenum disulfide quantum dot uniformly interspersed on the wrinkled graphene *** crumpled ball composite possesses excellent dispersity in polyalkylene glycol base oil without depending on surface *** with the conventional phosphate esters lubricant,our results indicate MGCB could vastly improve the lubrication performance of polyalkylene glycol with an extremely low concentration(0.05 wt%)at elevated temperature(150°C),showing a friction reduction of 47%and a wear reduction of 30%compared with the conventional phosphate esters lubricant(tricresyl phosphate,TCP).This is because crumpled ball potentiates synergistic lubrication effect within the boundary ***,we envision our designed self-dispersed MGCB has significant potential in tribological application at elevated temperature.

关键词： self-dispersed crumpled ball graphene molybdenum disulfide quantum dot high temperature tribological properties

Study on the mechanism of rapid formation ofu ultra-thick tribofilm by CeO_(2)nano additive and ZDDP

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Friction 2023年第1期11卷 48-63页

作者： Xue LEI Yujuan zhang shengmao zhang Guangbin YANG Chunli zhang Pingyu zhang National&Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004China

CeO_(2)nanoparticles are potential anti-wear additives because of their outstanding anti-wear and load-bearing ***,the shear-sintering tribo-film formation mechanism of oxide nanoparticles limits the tribo-film formation rate and thickness *** this study,by compounding with zinc dioctyl dithiophosphate(ZDDP),ultra-fine CeO_(2)nanoparticles modified with oleylamine(OM)can quickly form 2μm ultra-thick tribo-film,which is 10-15 times thicker than that of ZDDP and CeO_(2),*** ultra-thick tribo-film presents a nanocomposite structure with amorphous phosphate as binder and nano-CeO_(2)as filling phase,which leads to the highest loading capacity of composite *** results of adsorption experiments tested by dissipative quartz crystal microbalance(QCM-D)showed that the Ps value of additive has nothing to do with its equilibrium adsorption mass,but is directly proportional to its adsorption rate in 10 *** compound additive of CeO_(2)and ZDDP presented the co-deposition mode of ZDDP monolayer rigid adsorption and CeO_(2)viscoelastic adsorption on the metal surface,which showed the highest adsorption rate in 10 *** is found that the tribo-film must have high film forming rate and wear resistance at the same time in order to achieve super *** phosphate was formed from ZDDP and CeO,through tribochemistry reaction,which promotes the formation of an ultra-thick tribo-film with nanocomposite structure,which not only maintains the low friction characteristics of CeO,but also realizes high Pg and high load-carrying capacity.

关键词： CeO_(2)nanoadditives adsorption nanocomposite ultra-thick tribofilm zinc dioctyl dithiophosphate(7DDP)

Synergistic tribological effect between polyisobutylene succinimide-modified molybdenum oxide nanoparticle and zinc dialkyldithiophosphate for reducing friction and wear of diamond-like carbon coating under boundary lubrication

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Friction 2023年第11期11卷 2021-2035页

作者： Shuoshuo CHEN Ningning SONG shengmao zhang Yujuan zhang Laigui YU Pingyu zhang National&Local Joint Engineering Research Center for Applied Technology of Hybrid Nanomaterials Henan UniversityKaifeng 475004China

Organic molybdenum lubricant additive like molybdenum dialkyl dithiocarbamate(MoDTC)can cause wear acceleration of diamond-like carbon(DLC)coating coupled with steel under boundary lubrication,which hinders its industrial ***,polyisobutylene succinimide(PIBS),an organo molybdenum amide,was adopted to modify molybdenum oxide affording molybdenum polyisobutylene succinimidemolybdenum oxide nanoparticles(MPIBS-MONPs)with potential to prevent the wear acceleration of DLC *** thermal stability of MPIBS-MONPs was evaluated by thermogravimetric *** tribological properties as the additives in di-isooctyl sebacate(DIOS)were evaluated with MoDTC as a control;and their tribomechanism was investigated in relation to their tribochemical reactions and synergistic tribological effect with zinc dialkyldithiophosphate(ZDDP)as well as worn surface *** indicate that MPIBS-MONPs/ZDDP added in DIOS can significantly reduce the friction and wear of DLC coating,being much superior to *** is because MPIBS-MONPs and ZDDP jointly take part in tribochemical reactions to form a composite tribofilm that can increase the wear resistance of DLC ***,the molybdenum amide on MPIBS-MONPs surface can react with ZDDP to form MoS2 film with excellent friction-reducing ability;and MPIBS-MONPs can release molybdenum oxide nanoparticle to form deposited lubrication layer on worn *** as-formed composite tribofilm consisting of molybdenum oxide nanocrystal,amorphous polyphosphate,and molybdenum disulfide as well as a small amount of Mo2C accounts for the increase in the wear resistance of DLC coating under boundary lubrication.

关键词： molybdenum oxide nanoparticle zinc dialkyldithiophosphate(ZDDP) synergistic tribological effect diamond-like carbon(DLC)coating boundary lubrication wear resistance

Synthesis of water-soluble Cu nanoparticles and evaluation of their tribological properties and thermal conductivity as a water-based additive

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Friction 2019年第3期7卷 246-259页

作者： Junhua ZHAO Guangbin YANG Chunli zhang Yujuan zhang shengmao zhang Pingyu zhang Engineering Research Center for Nanomaterials Henan University

Efficient and sustainable use of water-based lubricants is essential for energy ***,the use of water-lubricated mechanical systems instead of conventional oil lubricants is extremely attractive from the viewpoint of resource *** this study,water-soluble Cu nanoparticles of size approximately 3 nm were prepared at room temperature(around 25 °C) via in-situ surface *** tribological behavior of the as-synthesized Cu nanoparticles as an additive in distilled water was evaluated using a universal *** results show that the as-synthesized Cu nanoparticles,as a water-based lubricant additive,can significantly improve the tribological properties of distilled *** particular,the lowest friction coefficient of 0.06 was obtained via lubrication with a concentration of 0.6 wt% of Cu nanoparticles in distilled water,which is a reduction of 80.6% compared with that obtained via lubrication with distilled water *** is considered that some Cu nanoparticles entered the contact area of the friction pairs to form a complex lubricating film and prevent direct contact of the friction ***,some Cu nanoparticles in the solution accelerate the heat transfer process,which also results in good tribological properties.

关键词： Cu nanoparticles water-soluble lubricant additive tribological properties

Controllable synthesis of different morphologies of CuO nanostructures for tribological evaluation as water-based lubricant additives

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Friction 2021年第5期9卷 963-977页

作者： Junhua ZHAO Guangbin YANG Yujuan zhang shengmao zhang Chunli zhang Chuanping GAO Pingyu zhang Engineering Research Center for Nanomaterials Henan UniversityKaifeng 475004China

In this study,water soluble CuO nanostructures having nanobelt,nanorod,or spindle morphologies were synthesized using aqueous solutions of Cu(NO_(3))_(2)·3H_(2)O and NaOH by adjusting the type of surface modifier and reaction *** effect of morphologies of these various CuO nanostructures as water‐based lubricant additives on tribological properties was evaluated on a UMT‐2 micro‐friction tester,and the mechanisms underlying these properties are *** three different morphologies of CuO nanostructures exhibited excellent friction‐reducing and anti‐wear *** mechanisms differed in the initial stage of frictional interactions,but in the stable stage,a tribochemical reaction film and adsorbed lubricious film on the rubbing surfaces played important roles in hindering direct contact between friction pairs,leading to improved tribological properties.

关键词： CuO nanostructures morphology water‐based lubricant additive tribological properties

Tribological properties and tribomechanism of nickel nanoparticles in-situ synthesized in rapeseed oil

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Friction 2024年第3期12卷 474-489页

作者： Wenya XU Guangbin YANG shengmao zhang Jun XU Yujuan zhang Tianhua SUN Ningning SONG Laigui YU Pingyu zhang Engineering Research Center for Nanomaterials Henan UniversityKaifeng 475004China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China

Nickel(Ni)nanoparticles can be enriched on the surface of iron-based frictional pairs,which provides the possibility to get rid of the competitive adsorption between the polar species of vegetable oil and the surface-active nano-additives *** this paper,nickel acetylacetonate was used as a precursor to in-situ synthesize nickel nanoparticles with an average diameter of about 12 nm in rapeseed oil(RO)as the reducing agent,surface modifier,and solvent as *** tribological properties of the as-synthesized Ni nanoparticles were evaluated with a four-ball tribometer,and their tribomechanism was investigated based on the characterizations of the tribofilm on rubbed steel surfaces by the scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).It was found that the Ni nanoparticles in-situ prepared in the RO with a mass fraction of 0.3%can reduce the wear scar diameter(WSD)of the steel ball by 36%.This is because,on the one hand,the Ni nanoparticles are adsorbed on the rubbed steel surfaces to repair or fill up the micro-pits and grooves *** the other hand,Ni nanoparticles participate in tribochemical reactions with atmospheric O and steel substrate to form the tribochemical reaction film on the rubbed steel surfaces with the assistance of friction-induced heat and applied normal *** addition,an amorphous carbon film is formed on the rubbed surface via the carbonization of base oil under the catalysis of Ni *** adsorbed Ni layer,the tribochemical reaction film,and the carbon layer comprise a composite tribofilm composed of amorphous carbon,polar fatty acid,metallic nickel,iron oxides,and nickel oxides on the rubbed steel surfaces,which contributes to significantly improving the antiwear ability and load-carrying capacity of the RO for the steel-steel sliding pair.

关键词： nickel(Ni)nanoparticles rapeseed oil(RO) in-situ synthesis tribological properties tribomechanism

Blend with the Sea Surface Temperature from Different Satellites and Their Comparison in the Southeast Pacific Ocean

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Journal of Ocean University of China 2023年第2期22卷 452-458页

作者： WU Yumei TANG Fenghua DAI Yang WANG Fei SHI Yongchuang zhang shengmao Key and Open Laboratory of Remote Sensing Information Technology in Fishing Resource East China Sea Fisheries Research InstituteChinese Academy of Fishery SciencesShanghai 200090China Key Laboratory of Fisheries Remote Sensing Ministry of Agriculture and Rural Affairs Shanghai 200090China

The daily sea surface temperature(SST)data from three kinds of different satellites of GMI,GOES and MODIS were applied to do the blend in the Southeast Pacific Ocean throughout the whole year of *** coverage rates of the SST of the blend result were improved highly and more stable throughout the whole year,compared with the result of the single satellite of GMI,GOES,and *** yearly average coverage rates of GMI,GOES,MODIS,and blend were 43%,48%,30%,and 76%,and their corresponding yearly average standard deviation(SD)were 4%,6%,7%,and 4%,*** the coverage rates of these three satellites were low from April to *** valid observation days calculated in the whole year over every grid were used to represent the spatial distribution patterns of the coverage *** spatial distribution patterns of coverage rates from GOES and MODIS were similar that their valid observation days were higher in the northwest area and lower in the south area,and those of GMI was contrary to the former *** ranges of valid observation day was from GOES,GMI,and MODIS were 0-364,6-254,and 9-231 d,*** the blend,all the observation day of every grid in the research region was enhanced(103-366 d).Especially the near shore and south area,and the minimum valid observation day increased largely from the single digits to hundreds digit.

关键词： sea surface temperature blend coverage rate observation day

The Potential Vertical Distribution of Bigeye Tuna (Thunnus obesus) and Its Influence on the Spatial Distribution of CPUEs in the Tropical Atlantic Ocean

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Journal of Ocean University of China 2020年第3期19卷 669-680页

作者： YANG Shenglong SONG Liming zhang Yu FAN Wei zhang Bianbian DAI Yang zhang Heng zhang shengmao WU Yumei College of Marine Sciences Shanghai Ocean UniversityShanghai 201306China Key Laboratory of Oceanic and Polar Fisheries Ministry of AgricultureEast China Sea Fisheries Research InstituteChinese Academy of Fishery SciencesShanghai 200090China Key and Open Laboratory of Remote Sensing Information Technology in Fishing Resource East China Sea Fisheries Research InstituteChinese Academy of Fishery SciencesShanghai 200090China

Understanding the potential vertical distribution of bigeye tuna(Thunnus obesus) is necessary to understand the catch rate fluctuations and the stock assessment of bigeye tuna. To characterize the potential vertical distribution of this fish while foraging and determine the influences of the distribution on longline efficiency in the tropical Atlantic Ocean, the catch per unit effort(CPUE) data were compiled from the International Commission for the Conservation of Atlantic Tunas and the Argo buoy data were downloaded from the Argo data center. The raw Argo buoy data were processed by data mining methods. The CPUE was standardized by support vector machine before analysis. We assumed the depths with the upper and lower limits of the optimum water temperatures of 15℃ and 9℃ as the preferred swimming depth, while the lower limit of the temperature(12℃) associated with the highest hooking rate as the preferred foraging depth(D12) of bigeye tuna during the daytime in the Atlantic Ocean. The preferred swimming depth and foraging depth range in the daytime were assessed by plotting the isobath based on Argo buoy data. The preferred swimming depth and vertical structure of the water column were identified to investigate the spatial effects on the CPUE by using a generalized additive model(GAM). The empirical cumulative distribution function was used to assess the relationship between the spatial distribution of CPUE and the depth of 12℃ isolines and thermocline. The results indicate that 1) the preferred swimming depth of bigeye tuna in the tropical Atlantic is from 100 m to 400 m and displays spatial variation;2) the preferred foraging depth of bigeye tuna is between 190 and 300 m and below the thermocline;3) the number of CPUEs peaks at a relative depth of 30 –50 m(difference between the 12℃ isolines and the lower boundary of the thermocline);and 4) most CPUEs are within the lower depth boundary of the thermocline levels(LDBT) which is from 160 m to 230 m. GAM analysis i

关键词： CPUE Argo buoy data Thunnus obesus vertical distribution generalized additive model Atlantic Ocean

The Combined Effect of Plastic Particles Size and Concentration on Rotifers’ (Brachionus plicatilis) Performance

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Journal of Ocean University of China 2022年第2期21卷 509-519页

作者： SUI Yanming WANG Senyang MOHSEN Mohamed zhang Longsheng SHEN Mengyan LIU Zhiquan NGUYEN Haidang zhang shengmao LI Kaixing LV Linlan DONG Xuexing School of Marine and Biological Engineering Yancheng Institute of TechnologyYancheng 224002China Department of Animal Production Faculty of AgricultureAl-Azhar UniversityNasr CityCairo 11884Egypt CAS Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China School of Life Sciences East China Normal UniversityShanghai 200241China Research Institute for Aquaculture No.1 Dinh Bang-Tu Son-Bac Ninh 16352Vietnam East China Sea Fishery Research Institute Chinese Academy of Fishery SciencesShanghai 200090China

The presence of microplastics in aquatic ecosystems is of increasing global ***-sized plastics,in particular,can penetrate the cell membrane and cause biological *** study evaluated the combined impacts of several polystyrene mi-crospheres’sizes and nominal concentrations on the overall performance changes of Brachionus *** animals were exposed to three microplastic sizes(0.08,0.5 and 6μm)and five nominal concentrations(0,0.5,2,8,32μg mL−1)for 20 *** results showed that the toxicological effect of particle size on rotifers did not significantly depend on the nominal *** interaction between the nominal concentration and size occurred only for body length and lorica ***,high nominal concentrations of microplastics that were close to nanometer size significantly impaired the overall vitality of rotifers,embodied in shortage of body type,delay in the arrival of maturity,reduction in the cumulative number of neonates,and the advance of the death *** comparison,fair-sized size(0.5 and 6μm)displayed non-significant damage except for individual *** notably,the net reproductive yield was only a third of what it was in the original environment,implying that there was not much fertility ***,with the development of rotifers,the adverse effects of polystyrene microsphere drive had become more and more serious.

关键词： microplastic zooplankton environmental stress life-history parameters