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CompOSITION EFFECT ON DRY SLIDING WEAR BEHAVIORS OF Ti-B-N THIN FILMS

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 300-306页

作者： p.Sit Y.H.Lu H.Chen Z.F.Zhou Y.G.Shen K.Y.Li DepartmentofphysicsandMaterialsScience CityUniversityofHongKongKowloonHongKongChina DepartmentofphysicsandMaterialsScience CityUniversityofHongKongKowloonHongKongChina／／DepartmentofManufacturingEngineeringg：EngineeringManagementCityUniversityofHongKongKowloonHongKongChina DepartmentofManufacturingEngineering＆EngineeringManagement CityUniversityofHongKongKowloonHongKongChina

Friction and sliding wear behaviour of Ti-B-N coatings against AISI440C steel ba ll and WC-6wt%Co ball were studied by using pin-on-disk tribometer along with mi crostructure characterization using optical microscopy (om), scanning electron m icroscopy (SEM) and X-ray photoelectron spectroscopy (XpS). It is shown that the wear resistance of film depended on the wear mechanism. In the case of AISI440C steel, adhesive wear were pre-dominant and the wear rate increased sharply to a maximum when N content reach ~38at.%. This might be related to the change of fi lm microstructure and phase configuration, so the least adhesive transfer of tri bo-film was observed. If WC-6wt%Co ball was used, less deformation wear debris w as observed, this was responsible for the rise of wear rate. Despite of differen t wear modes, friction coefficients in both cases were found to depend mainly on the formation and the amount of h-BN phase. Elemental analysis by energy disper sive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XpS) revealed that oxygen participated in the wear behavior by reacting with films to form the deb ris comprised of various types of Ti oxide including TiO, TiO2 and Ti2O3 , which increased wear resistance.

关键词： dry sliding wear friction coefficient oxidation Ti-B-N wear

Hematopoietic Stem and progenitor Cell(HSpC)Mobilization Responses to Different Exercise Intensities in Young and Older Adults

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Journal of Science in Sport and Exercise 2020年第1期2卷 47-58页

作者： Joshua p.Nederveen Jeff Baker George Ibrahim Victoria Ivankovic Michael E.perciva Gianni parise Department of Kinesiology McMaster UniversityHamiltonON L8S 4L8Canada Child and Youth Mental Health program McMaster University Medical CentreHamiltonON L8N 3Z5Canada

Introduction Hematopoietic stem and progenitor cells(HSpC)are responsible for the reconstitution of blood cells and thought to contribute to peripheral tissue *** acute exercise in young adults,HSpC are mobilized from their niche in bone marrow into circulation,however the kinetics of mobilization following exercise is not well understood in older *** the present study,we aimed to investigate how exercise intensity influences mobilization of specific subpopulations of HSpC,and how mobilization is affected by *** Healthy older men(om;69.9±2.0 years)and young men(YM;21.5±0.8 years)performed three separate bouts of exercise on a cycle ergometer:70%of their peak work rate(WRpeak)until volitional fatigue,30%of their WRpeak work matched to the 70%WRpeak trial,and a high intensity interval training(HIIT)*** samples were collected before,immediately post,and 10,30,and 60 min *** blood cells,hematocrit,and mononuclear cells isolated by density gradient centrifugation were quantified using flow *** Mononuclear cells,CD34+,CD34+/CD38+,CD34+/CD110+,CD3+/CD(16+56)+,CD11c+/CD123-,and CD11c-/CD123+cells per millilitre of blood increased immediately post-exercise,but predominately in the 70%WRpeak trial in both om and *** Taken together,our evidence suggests that higher intensity exercise but also volume is necessary for the mobili-zation of ***,the pattern of mobilization was nearly identical in om as compared to YM though to a lesser extent than their younger counterparts.

关键词： Exercise Hematopoietic stem cells pmgenitor cells Aging F1ow cytometry

EFFECTS OF TREATMENT TIME ON CORROSION OF DIFFUSION-ALLOYED COATINGS OF pURE MAGNESIUM

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Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 72-78页

作者： Y.p. Ma J. Li J. Zhu L. Yang Y.G. Liu Z.Y. Li F. Zhao School of Metallurgic Engineering Xi＇an University of Architecture ＆ Technology Xi＇an 710055 China

The corrosion resistance of pure magnesium with surface alloying layer obtained by a solid diffusion alloying technique has been analyzed. To establish the optimum treatment time, the experiments were performed at 480℃ for different solid diffusion time （8, 16, and 24h）. The diffusion interaction effectiveness between Zn, Al mix powder and the sample surface, depending on the treatment time for diffusion at given temperatures, has an obvious influence on corrosion resistance and corrosion mechanism. Corrosion properties were studied using the constant immersion test （in 3.0% NaCl solution, temperature is （28±1）℃, and time is 96h）. Optical microscopy （om） and EDS （energy dispersive spectrum） composition analysis were used to examine the cross-sectional microstructural characteristics of alloyed layer of treated samples. It is shown that in comparison with the untreated samples, the treated ones possess a better corrosion resistance. The Al5Mg11Zn4 phase, which formed as a continuous phase due to the diffusion of Al, Zn, and Mg elements and subsequent interaction on the outermost layer of diffusion alloying zones （especially the samples treated for 24h at 480℃）, was inert to the chloride solution compared with pure magnesium and acted as a corrosion barrier, and therefore the best corrosion resistance was obtained. This protective action of Al5Mg11Zn4 phase was found to change with its amount, which was controlled by the diffusion time at given temperature. It was concluded that the continuous Al5Mg11Zn4 phase （Wp-zone） of the reacted layer in pure magnesium was beneficial from the point of view of corrosion resistance.

关键词： pure magnesium solid diffusion treatment time microstructure corrosion

Microstructure and corrosion behavior of Mg-Sn-Ca alloys after extrusion

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中国有色金属学会会刊：英文版 2009年第1期19卷 40-44页

作者： T. ABU LEIL N. HORT W. DIETZEL C. BLAW ERT Y. HUANG K. U. KAINER K. p. RAO GKSS Forschungszentrum Geesthacht GmbH Max-planck Strasse 1 Geesthacht 21502 Germany City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong

Mg-Sn-Ca alloys promise a reasonable corrosion resistance in combination with good creep resistance, likely due to the presence of Ca2-xMgxSn and other phases. The selected alloys with 3% Sn and Ca in the range of 1%-2% have been extruded in order to achieve more homogeneous microstructure compared with the as-cast alloys. Optical microscopy(om) and X-ray diffraction(XRD) techniques were used to study the microstructure and phases of these alloys. The corrosion behavior of these alloys was investigated by means of salt spray test and potentio-dynamic measurements. The results obtained on the alloys Mg-3Sn (T3), Mg-3Sn-1Ca (TX31), and Mg-3Sn-2Ca (TX32) indicate the presence of the same phases in as-cast and after extrusion, namely Mg2Sn, Ca2-xMgxSn, and Ca2-xMgxSn/Mg2Ca, respectively. However, due to the occurrence of extensive recrystallization in the extrusion process, the grain size has significantly reduced after extrusion. The reduction leads to the improvement of the corrosion resistance after extrusion which is then comparable with the commercial alloy AZ91D.

关键词： Mg-Sn-Ca合金腐蚀镁合金金属腐蚀

Effects of Different Energy Levels on Nutrient Utilization and Serum Biochemical parameters of Early-Weaned Calves

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Agricultural Sciences in China 2010年第5期9卷 729-735页

作者： ZHANG Rong, DIAO Qi-yu, ZHANG Nai-feng, TU Yan and JIANG Cheng-gang Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, p.R.China Feed Research Institute Chinese Academy of Agricultural Sciences Beijing 100081 P.R.China

Current study was performed to investigate the effects of different energy levels on nutrient digestion metabolism and serum biochemical parameters of early-weaned calves. Twelve neonatal Holstein calves were selected and assigned randomly to receive 1 of 3 treatments that contained 18.51, 19.66 and 20.80 MJ kg^-1 gross energy, respectively （n=4 per treatment）. Digestion and metabolism trials were carried out in 5 phases （12-20, 22-30, 32-40, 42-50, and 52-60 d of age）. At the same time, blood metabolites were determined at 21, 31, 41, 51, and 61 d of age prior to morning feeding. The results indicated that either dry matter （DM）, organic matter （om） and gross energy （GE） apparent digestibility or N and p retention tended to increase as age advanced; the average value of DM and om apparent digestibility and Ca retention in high-energy treatment was significantly lower than that of other groups （p 〈 0.05）; there were no significant differences in the concentration of serum glucose, triglyceride and urea N among treatments, whereas a significant effect of age was found on the level of triglyceride （p 〈 0.05）. To sum up, medium-energy milk replacer seems to be more beneficial for GE digestibility and N utilization, whereas low-energy milk replacer appears to be more rewarding for Ca and p utilization.

关键词： calf milk replacer energy apparent digestibility metabolic rate

NOISE REDUCTION METHOD FOR OCT IMAGES BASED ON EMpIRICAL MODE DECompOSITION

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Journal of Innovative Optical Health Sciences 2013年第2期6卷 17-21页

作者： OLEG O.MYAKININ DMITRY V.KORNILIN IVAN A.BRATCHENKO VALERIY p.ZAKHAROV ALEXANDER G.KHRAMOV photonics Laboratory Samara State Aerospace University Moskovskoe shosse 34 SamaraRussia 443086Russia Laboratory of Laser Measurements Image processing System Institute of Russian Academy of Science Molodogvardeyskaya Street 151 Samara 443001Russia

In this paper,the new method for OCT images denoizing based on empirical mode decomposition(EMD)is *** noise reduction is a very important process for following operations to analyze and recognition of tissue *** method does not require any additional operations and hardware *** basics of proposed method is *** improvement of noise suppression om example of edge detection procedure using the classical Canny's algorithm without any additional pre-and post-proc essing operations is *** of raw-segmentation in the automatic diagnostic process between a tissue and a mesh implant is shown.

关键词： Optical coherence tomography empirical mode decomposition denoizing thresholding

The use of dielectrophoresis in oral cancer

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中国口腔颌面外科杂志 2008年第B5期6卷 151-152页

作者： Hayley J. Mulhall Fatima H. Labeed Michael p. Hughes Mark p. Lewis School of Biomedical Engineering University of Surrey Guildford Surrey GU2 7XH Eastman Dental Institute for Oral Health Care Sciences University College. London 256 Gray's Inn Road. London WC1X 8LD UK

purpose: Oral squamous cell carcinoma (OSCC) is the eighth most common cancer worldwide。If early stage (stage I) diagnosis occurs, the 2 year survival rate is 87.5% (Cancer Research, U。K。)。However, most oral cancers are diagnosed at late stage and, consequently, the overall survival rate for OSCC remains poor (approximately 50% at 5 years post-presentation)。A novel screening assay is proposed in which a malignant cell population derived fi'om the oral mucosa is differentiated fi'om normal oral cells on the basis of its dielectric properties。Methods: Dielectrophoresis (DEp) is a phenomenon whereby a force is exerted on a dielectric particle (a cell) when exposed to a non uniform electric field。The magnitude and direction of the force is dependent, in part, on the dielectric properties of the cell。Therefore, cell populations which exhibit distinct dielectric characteristics will experience different DEp forces。In this study, DEp has been used to determine the dielectric properties of a number of OSCC cell lines and normal human keratinocytes (NHK)。In addition, cells derived from organotypic models of the normal oral mucosa and models of OSCC have been analysed with DEp and their dielectric phenotypes determined。Results: The results show significant electrophysiological differences in the cytoplasm of NHK's and malignant keratinocytes。Conclusion: It is proposed that DEp has the potential to be used in a clinical setting as a non-invasive screening tool for OSCC。

关键词：口腔癌治疗方法介电泳临床分析诊断技术

Effect of temperature and strain rate on compressive response of extruded magnesium nano-composite

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Journal of Magnesium and Alloys 2015年第3期3卷 224-230页

作者： B.Selvam p.Marimuthu R.Narayanasamy V.Senthilkumar K.S.Tun M.Gupta Department of Mechanical Engineering Mookambigai College of EngineeringPudukkottaiTamilnadu 622502India Syed Ammal Engineering College RamanathapuramTamilnadu 623502India Department of production Engineering National Institute of TechnologyTiruchirappalliTamilnadu 620015India Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1Singapore 117576Singapore

The hot deformation behaviour of extruded magnesium-zinc oxide nano composite has been studied using hot compression *** test was conducted in the temperature range of 250-400℃ and in the strain rate range of 0.01 to 1.5 s^(−1).The processing map was obtained using the power dissipation efficiency with the functions of temperature and strain *** workability and instability domains were observed in the processing map for a nano *** optical microscopy(om),scanning electron microscopy(SEM)and transmission electron microscopy(TEM)images were used to confirm the formation of dynamic recrystallization(DRX),dynamic recovery(DRY)and instability *** workability region of the composite was identified at a working temperature of 400℃ and the strain rate of 0.01 s^(−1) from the processing *** instability regions were observed at higher strain rates(>0.1 s^(−1))and temperatures(250-400℃).

关键词： Metal matrix composites powder metallurgy processing map Strain rate Instability Nano-composite

硼酸-硫酸阳极氧化2A97Al-Cu-Li合金在热带海洋大气环境中的初期腐蚀机理

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材料工程 2016年第9期44卷 8-15页

作者：骆晨 Sergiu p.Albu 孙志华汤智慧陆峰 Xiaorong Zhou 北京航空材料研究院航空材料先进腐蚀与防护航空科技重点实验室北京100095 曼彻斯特大学材料学院

采用光学显微镜、扫描电镜、能谱仪、电化学阻抗谱测试结合超薄切片,分析阳极氧化2A97Al-Cu-Li合金在大气腐蚀前后的微观形貌、化学成分及电化学性能。结果表明:在不同温度利用含有硼酸-硫酸或酒石酸-硫酸组合的电解液生长膜层时,硼酸... 详细信息

采用光学显微镜、扫描电镜、能谱仪、电化学阻抗谱测试结合超薄切片,分析阳极氧化2A97Al-Cu-Li合金在大气腐蚀前后的微观形貌、化学成分及电化学性能。结果表明:在不同温度利用含有硼酸-硫酸或酒石酸-硫酸组合的电解液生长膜层时,硼酸添加和较高温度允许较大的电流密度通过,使膜生长加速;对于不同电解液,孔的几何构形和结构相似;硼酸-硫酸阳极氧化试样在热带海洋大气环境中暴露1个月后,出现主要由O,Al,Cl,Cu组成的分散性黑色锈斑,表面产生白色沉淀;随着户外暴露时间的延长,合金发生严重的点蚀并深入合金内部,腐蚀的扩展与θ相粒子有关。

关键词：硼酸-硫酸阳极氧化 Al-Cu-Li合金大气腐蚀点蚀