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Vacuum current-carrying tribological behavior of MoS2-Ti films with different conductivities

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Chinese Physics B 2022年第6期31卷 563-571页

作者： Lu-Lu Pei Peng-Fei Ju Li Ji Hong-Xuan Li Xiao-Hong Liu Hui-Di Zhou Jian-Min Chen Key Laboratory of Science and Technology on wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Shanghai Aerospace Equipment Manufacture Shanghai 200245China

Current-carrying sliding is widely applied in aerospace equipment,but it is limited by the poor lubricity of the present materials and the unclear tribological *** study demonstrated the potential of MoS_(2)-based materials with excellent lubricity as space sliding electrical contact materials by doping Ti to improve its *** tribological behavior of MoS_(2)-Ti films under current-carrying sliding in vacuum was studied by establishing a simulation evaluating ***,the noncurrent-carrying sliding and static current-carrying experiments in vacuum were carried out for comparison to understand the tribological *** addition to mechanical wear,the current-induced arc erosion and thermal effect take important roles in accelerating the *** erosion is caused by the accumulation of electric charge,which is related to the conductivity of the *** the current-thermal effect softens the film,causing strong adhesive wear,and good conductivity and the large contact area are beneficial for minimizing the thermal *** the moderate hardness and good conductivity of MoS_(2)-Ti film contribute to its excellent current-carrying tribological behavior in vacuum,showing a significant advantage compared with the traditional ones.

关键词： MoS2-Ti films conductivity current-carrying tribological behavior vacuum

Corrosion Behaviors of Pure Titanium and Its Weldment in Simulated Desulfurized Flue Gas Condensates in Thermal Power Plant Chimney

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Acta Metallurgica Sinica(English Letters) 2015年第4期28卷 477-486页

作者： Zheng-Bing Wang Hong-Xiang Hu Chun-Bo Liu Huai-Ning Chen Yu-Gui Zheng Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of Sciences Center for wear and Corrosion Resistant Materials Huadian Zhengzhou Mechanical Design Institute Co.Ltd. Laboratory of Properties and Reliable Joining of Welded Joints Institute of Metal ResearchChinese Academy of Sciences

The corrosion behaviors of pure titanium and its weldment welded by tungsten inert gas （TIG） welding in simulated desulfurized flue gas condensates in thermal power plant chimney were investigated using potentiodynamic polarization, electrochemical impedance spectroscopy （EIS） and immersion tests. The effects of heat input and shielding gases on the corrosion behavior of the welded titanium were also studied. Grain coarsening and Widmanst^itten structure were found in both the fusion zone and the heat-affected zone. The welded titanium exhibited active-passive behavior in the simulated condensates. Both the polarization curves and EIS measurements confirmed that TIG welding process with different parameters had few effects on the corrosion behavior. It was proved that the microstructure changes were not the key material factors affecting the corrosion behavior of pure titanium under the test conditions, while the oxide film had remarkable effect on improving the corrosion resistance.

关键词： Pure titanium Tungsten inert gas welding Simulated desulfurized flue gas condensates Corrosion behavior Microstructure Oxide film

Tribological properties of PTFE-based fabric composites at cryogenic temperature

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Friction 2024年第2期12卷 245-257页

作者： Mingkun XU Zidan WANG Lihe GUO Liming TAO Tianbao MA Tingmei WANG Qihua WANG Key Laboratory of Science and Technology on wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Fabric composites are widely employed in self-lubricating bearing liners as solid lubrication *** the tribological behaviors of fabric composites have been extensively studied,the cryogenic tribological properties and mechanisms have been scarcely reported and are largely unclear to instruct material design for aerospace and other high-tech ***,the tribological properties of polytetrafluoroethylene(PTFE)-based hybrid-fabric composites were investigated at cryogenic and ambient temperatures in the form of pin-on-disk friction under heavy *** results suggest that the friction coefficients of the hybrid-fabric composites obviously increase with a decrease in wear when the temperature drops from 25 to−150°***,thermoplastic polyetherimide(PEI),as an adhesive for fabric composites,has better cryogenic lubrication performance than thermosetting phenol formaldehyde(PF)resin,which can be attributed to the flexible chemical structure of *** excellent lubrication performance of hybrid-fabric composites is attributed to the transfer film formed by PTFE fibers on the surface of fabrics.

关键词： cryogenic temperatures fabric composites friction and wear transfer film

Colorectal cancer in inflammatory bowel disease:What is the real magnitude of the risk?

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World Journal of Gastroenterology 2012年第29期18卷 3839-3848页

作者： Jessica K Dyson Matthew D Rutter Gastroenterology North Tyneside General HospitalRake LaneNorth ShieldsTyne and Wear NE29 8NHUnited Kingdom University Hospital of North Tees Hardwick RoadStockton TS19 8PEUnited Kingdom

The association between inflammatory bowel disease(IBD) and colorectal cancer(CRC) has been recognised since 1925 and still accounts for 10%-15% of deaths in ***-associated CRC(IBD-CRC) affects patients at a younger age than sporadic *** prognosis for sporadic CRC and IBD-CRC is similar,with a 5-year survival of approximately 50%.Identifying at risk patients and implementing appropriate surveillance for these patients is central to managing the CRC risk in *** increased risk of colorectal cancer in association with IBD is thought to be due to genetic and acquired *** link between inflammation and cancer is well recognised but the molecular biology,immune pathobiology and genetics of IBD-CRC are areas of much ongoing *** review examines the literature relating to IBD-CRC,focusing on the incidence of IBD-CRC and examining potential risk factors including age at diagnosis,gender,duration and extent of colitis,severity of inflammation,family history of sporadic CRC and co-existent primary sclerosing cholangitis(PSC).Confirmed risk factors for IBD-CRC are duration,severity and extent of colitis,the presence of co-existent PSC and a family history of *** is insufficient evidence currently to support an increased frequency of surveillance for patients diagnosed with IBD at a younger ***-based guidelines advise surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis,with the interval for further surveillance guided by risk factors(extent of disease,family history of CRC,post-inflammatory polyps,concomitant PSC,personal history of colonic dysplasia,colonic strictures).There is a move away from using random colonic biopsies towards targeted biopsies aimed at abnormal areas identified by newer colonoscopic techniques(narrow band imaging,chromoendoscopy,confocal microendoscopy).

关键词： Colorectal cancer Inflammatory bowel disease Ulcerative colitis Crohn's disease Risk

Polydopamine-modified metal-organic frameworks nanoparticles enhance the corrosion resistance and bioactivity of polycaprolactone coating on high-purity magnesium

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Journal of Magnesium and Alloys 2024年第5期12卷 2070-2089页

作者： Qingyun Fu Shaojie He Junjie Yang Ziyu Su Ping Li Xincheng Yu Weihong Jin Shulan Xu Zhentao Yu Dingsheng Zha Center of Oral Implantology Stomatological HospitalSouthern Medical UniversityGuangzhouChina Panyu Hospital of Chinese Medicine Guangzhou 511400China Institute of Advanced wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou 510632China First Affiliated Hospital of Jinan University Guangzhou 510630China

Biodegradable magnesium(Mg)and its alloys exhibit excellent biocompatibility and mechanical compatibility,demonstrating tremendous potential for applications in ***,the rapid degradation rate has limited their clinical ***(PCL)is commonly employed as a polymer coating to impede the rapid degradation of ***,its long-term anti-corrosion capability and bioactivity are *** address these issues,polydopamine(PDA)-modified zeolitic imidazolate framework-8(PZIF-8)bioactive nanoparticles are fabricated and incorporated into the PCL *** PZIF-8 particles,featuring catechol motifs,can enhance the compactness of the PCL coating,reduce its defects,and possess biomineralization ability,thereby effectively improving its anti-corrosive and bioactive ***,the active substances released from the degradation of the PZIF-8 particles such as Zn^(2+)and PDA are beneficial for *** corrosion tests indicate that the corrosion current density of PCL-treated sample decreases by more than one order of magnitude and the amount of H_(2)released decreases from 0.23±0.12 to 0.08±0.08 ml cm^(-2)after doping with the ***,the improved corrosion resistance and released PDA and Zn^(2+)from the coating can promote osteogenic differentiation by up-regulating the expression of alkaline phosphatase activity,related osteogenic genes,and *** addition,in vivo implantation experiments in rabbit femur defects further offer strong evidence that the doping of PZIF-8 nanoparticles accelerates bone reconstruction of the PCL *** summary,this work implies a new strategy to fabricate a PCL-based coating on Mg-based implants by introducing the PZIF-8 particles for orthopedic applications.

关键词： Polydopamine ZIF-8 High-purity magnesium Polycaprolactone coating Anticorrosion Bone regeneration

Tribological behavior of shape memory cyanate ester materials and their tunable friction mechanism

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Friction 2023年第10期11卷 1794-1803页

作者： Zhangzhang TANG Lihe GUO Mingkun XU Hongwei RUAN Jing YANG Tingmei WANG Jianqiang ZHANG Qihua WANG Yaoming ZHANG Key Laboratory of Science and Technology on wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China College of Petrochemical Technology Lanzhou University of TechnologyLanzhou 730050China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

High-performance polymer friction materials with tunable tribological behavior to fit varied work conditions remain a challenge of widespread interest for a variety of *** memory polymer exhibits morphing and modulus changing over temperature changing provides a promising material to adjust the friction ***,we investigated the tribological properties of shape memory cyanate ester(SMCE)under different *** SMCE exhibits the tribological behavior of good friction material with stable high coefficient of friction(COF)and a low wear ***,the COF increases and wear rate decreases with the temperature increasing show the tunable friction property of the *** propose a new model of wear-compensation through shape recovery to explain the adjustable friction behavior of thermal-responsive polymer from the aspect of shape recovery and energy *** study provides a high-performance friction material and paves the route for the application of shape memory polymer(SMP)in tribology field with tunable property.

关键词： tribological behavior shape memory polymer cyanate ester tunable friction wear rate

Characterization and processing of talc-magnesite from the Zinelbulak deposit

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Mining Science and Technology 2010年第3期20卷 415-420,433页

作者： HOJAMBERDIEV Mirabbos ARIFOV Pulat TADJIEV Kamil XU Yunhua New York State College of Ceramics Alfred University Alfred 14802 USA Institute of General and Inorganic Chemistry Uzbekistan Academy of Sciences Tashkent 100170 Uzbekistan Institute of wear Resistance Material Xi'an University of Architecture and Technology Xi 'an 710055 China

The characteristics of talc-magnesite from the Zinelbulak deposit(Uzbekistan) were investigated via X-ray diffraction, differential thermal analysis,infrared spectroscopy and optical *** mineralogical composition of the Zinelbulak talc-magnesite consists of 52 wt.%talc,43 wt.%carbonates and 5 wt.%of the iron-containing minerals magnetite,siderite and *** analysis confirmed the presence of carbonates in two forms:magnesite and *** tests revealed that talc and magnesite particles are completely separated after a grinding process carried out for 10～12 *** distribution of the yield of talc and magnesite,as a function of the particle size,shows an irregular feature in that a comparatively coarser sample(>0.1 mm) is richer in magnesite and poor in talc while a comparatively finer sample(<0.1 mm) has a composition poorer in *** dressability of the Zinelbulak talc-magnesite was tested using conventional gravity concentration,flotation and electromagnetic *** concentration was found to be the most economic initial process for the complete separation of magnesium carbonate and *** flotation and magnetic separation techniques could further increase the yield of high quality magnesite and *** samples prepared by heating the separated magnesite at 1600℃for 2 h met the State Standards for refractory materials.

关键词： talc-magnesite grinding froth flotation gravity concentration magnetic separation

Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

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Rare Metals 2024年第4期43卷 1815-1827页

作者： Sheng-Feng Zhou Yu Long Yan-Liang Yi Cheng Deng Lian-Xi Hu Institute of Advanced wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,*** a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding

Patient reported outcome measures in anterior cruciate ligament rupture and reconstruction:The significance of outcome score prediction

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World Journal of Clinical Cases 2022年第30期10卷 10939-10955页

作者： Oday Al-Dadah Lee Shepstone Simon T Donell Translational and Clinical Research Institute Faculty of Medical SciencesNewcastle UniversityNewcastle-upon-Tyne NE24HHTyne and WearUnited Kingdom Department of Trauma and Orthopaedic Surgery South Tyneside District HospitalSouth Shields NE340PLTyne and WearUnited Kingdom Department of Medical Statistics Norwich Medical SchoolUniversity of East AngliaNorwich NR47TJNorfolkUnited Kingdom Norwich Medical School University of East AngliaNorwich NR47TJNorfolkUnited Kingdom

BACKGROUND Numerous anterior cruciate ligament(ACL) clinical outcome measures ***,the result of one score does not equate to the findings of another even when evaluating the same patient *** To investigate if statistically derived formulae can be used to predict the outcome of one knee scoring system when the result of another is known in patients with ACL rupture before and after *** Fifty patients with ACL rupture were evaluated using nine clinical outcome *** included Tegner Activity Score,Lysholm Knee Score,Cincinnati Knee Score,International Knee Documentation Committee(IKDC) Objective Knee Score,Tapper and Hoover Meniscal Grading Score,IKDC Subjective Knee Score,Knee Outcome Survey-Activities of Daily Living Scale(KOS-ADLS),Short Form-12 Item Health Survey and Knee Injury and Osteoarthritis Outcome *** patients underwent an ACL reconstruction and were reassessed *** The mean total of each of the nine outcome scores appreciably differed from each *** correlations and regressions were found between most of the outcome scores and were stronger *** strongest correlation was found between Cincinnati and KOS-ADLS (r=0.91,P<0.001).The strongest regression formula was also found between Cincinnati and KOS-ADLS (R~2=0.84,P<0.001).CONCLUSION The formulae produced from this study can be used to predict the outcome of one knee score when the results of the other are *** formulae could facilitate the conduct of systematic reviews and meta-analysis in studies relating to ACL injuries by allowing the pooling of substantially more data.

关键词： Anterior cruciate ligament Prediction Regression Correlation Patient reported outcome measures Reconstruction Rupture