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Antibacterial Properties of an Austenitic Antibacterial Stainless Steel and Its Security for Human Body

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Journal of Materials Science & Technology 2007年第3期23卷 333-336页

作者： ke yang Manqi LV Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

An austenitic antibacterial stainless steel is reported in this paper. The very fine and dispersive ε-Cu precipitations in the matrix of the antibacterial steel after the antibacterial treatment endow the steel with antibacterial function. The antibacterial function is strong, long-term and broad-spectrum, and can be maintained even after repeated wear and long time dipping in water. The steel is safe for human body and could be used widely in daily application.

关键词： Antibacterial Austenitic steel Body security

Novel Cu-bearing stainless steel:A promising food preservation material

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Journal of Materials Science & Technology 2022年第18期113卷 246-252页

作者： Jinlong Zhao Chunguang yang ke yang Shi-changxu Innovation Center for Advanced Materials Institute of Metal Research Chinese Academy of Sciences

*** Food spoilage microorganism results in food *** draw the nutrients from food to promote their own growth and re-production,so that the food lost original nutritional value,organi-zational characteristics and sensory *** in,the most com-mon food spoilage is caused by bacteria and *** spoilage not only deprives food edible value,but also poses serious major hazard threats to human *** of the physical and chem-ical indexes of food caused by food spoilage can lead to occurrence of acute and chronic diseases in human and even death in severe cases[1,2].According to the data compiled by the World Food and Agriculture Organization(WFAO)in 2019,one third of food is lost globally each year,and the food spoilage caused by microorgan-isms is the main reason of the loss[3,4].Although food preserva-tion technology which can slow down the process of food spoilage has made rapid progress,improper food preservation method is still a common problem in the whole world.

关键词： threat own globally

A note on the definition of fractional derivatives applied in rheology

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Acta Mechanica Sinica 2011年第6期27卷 866-876页

作者： Fan yang ke-Qin Zhu Department of Engineering Mechanics Tsinghua University 100084 Beijing China

It is known that there exist obivious differences between the two most commonly used definitions of fractional derivatives-Riemann-Liouville （R-L） definition and Caputo definition. The multiple definitions of fractional derivatives in fractional calculus have hindered the application of fractional calculus in rheology. In this paper, we clarify that the R-L definition and Caputo definition are both rheologically imperfect with the help of mechanical analogues of the fractional element model （Scott-Blair model）. We also clarify that to make them perfect rheologically, the lower terminals of both definitions should be put to ∞. We further prove that the R-L definition with lower terminal a →∞ and the Caputo definition with lower terminal a →∞ are equivalent in the differentiation of functions that are smooth enough and functions that have finite number of singular points. Thus we can define the fractional derivatives in rheology as the R-L derivatives with lower terminal a →∞ （or, equivalently, the Caputo derivatives with lower terminal a →∞） not only for steady-state processes, but also for transient processes. Based on the above definition, the problems of composition rules of fractional operators and the initial conditions for fractional differential equations are discussed, respectively. As an example we study a fractional oscillator with Scott-Blair model and give an exact solution of this equation under given initial conditions.

关键词： Fractional derivatives Rheology Riemann-Liouville definition Caputo definition

Cytotoxicity of Ti–6Al–4V–5Cu Alloy to MC3T3-E1 Cells

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Acta Metallurgica Sinica(English Letters) 2021年第5期34卷 694-700页

作者： Ji Zhang Ling Ren ke yang Institute of Metal Research Chinese Academy of SciencesShenyang110016China

The aim of this work was to study the cytotoxicity of Ti–6 Al–4 V–5 Cu(TC4–Cu)alloy for dental applications and evaluate the cell viability of diff erent fabricated TC4–Cu alloys in contact with MC3 T3-E1 cells in ***–6 Al–4 V(TC4)alloy was used as a negative control to evaluate the cytotoxicity level of TC4–Cu alloy so as to provide basic support for the dental clinical *** group TC4 and experimental group TC4–Cu with diff erent fabrications were incubated in the cell culture *** absorbance value of mouse osteoblast MC3 T3-E1 cells was detected by CCK-8 assay after 1,3 and 7 days,*** relative proliferation rate of cells was calculated,and then the toxicity level was valued for each *** morphology on the surface was also studied by observing the cytoskeleton through F-actin filament *** experimental results showed that the absorbance values for the experimental and the negative control groups were not same at diff erent time *** with diff erent fabricated TC4–Cu alloys,the annealing-TC4–Cu alloy showed much better *** mouse osteoblast MC3 T3-E1 cells cultured with annealing-TC4–Cu,rolling-TC4–Cu and solution+aging-TC4–Cu have no toxic eff ects,and these alloys could promote the proliferation of mouse osteoblasts.

关键词： Cytotoxicity Ti–6Al–4V–5Cu alloy Fabrication Biocompatibility

Development of a New-Type Multiple-Source Heat Pump with Two-Stage Compression

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Journal of Thermal Science 2019年第4期28卷 635-642页

作者： ZHONG Xiaohui yang Hailong yang ke XU Jianzhong Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China College of Metallurgy and Energy North China University of Science and TechnologyTangshan 063009China

A new-type multiple-source heat pump cycle with two-stage compression was established on the basis of the problems of similarly existing heat *** equivalent temperature levels of typical evaporators are applied to the different heat sources of the proposed cycle,and the high-temperature heat sources are shown to enhance vapor ***,the mathematical model and prototype are developed,and the results from experimental simulation and validation showed that the solar collector can improve the heating performance of the proposed heat pump *** the middle-temperature heating period,the outdoor temperature is less than-25℃,and the average coefficient of performance(COP)value of the proposed heat pump was 4.2,which was greater than the COPs of conventional ground source heat pumps.

关键词： multiple-source heat pump two-stage compression solar collector simulation

Formation of carbonitride precipitates in hardfacing alloy with niobium addition

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Rare Metals 2013年第1期32卷 52-56页

作者： ke yang Qin yang Ye-Feng Bao College of Mechanical and Electrical Engineering Hohai University

Niobium, as the most effective second-phase forming element, was added in the Fe-Crl3-C-N hard- facing alloy to get carbonitride precipitates. Morphology and composition of carbonitride in the hardfacing alloy were studied by optical microscopy, scanning electron microscopy, and electron probe microanalyzer. The ther- modynamics and the effect on the matrix of the formation of carbonitride were also discussed. It was found that niobium carbonitrides are complex Nb（C, N） precipitate distributed on grain boundary and matrix of the hardfacing alloy. Under as-welded condition, primary carbonitride particles were readily precipitated from the hardfacing alloy with large size and morphology as they were formed already during solidification. Under heat treatment condi- tion, a large number of secondary carbonitrides can pre- cipitate out with very fine size and make a great secondary hardening effect on the matrix. As a result, addition of niobium in the hardfacing alloy can prevent the formation of chromium-rich phase on grain boundaries and inter- granular chromium depletion.

关键词： Niobium Carbonitride Hardfacing alloy Precipitate

Multi-objective steady-state optimization of two-chamber microbial fuel cells

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Chinese Journal of Chemical Engineering 2017年第8期25卷 1000-1012页

作者： ke yang Yijun He Zifeng Ma Shanghai Electrochemical Energy Devices Research Center Department of Chemical Engineering Shanghai Jiao Tong University

A microbial fuel cell(MFC)is a novel promising technology for simultaneous renewable electricity generation and wastewater *** non-comparable objectives,*** density,attainable current density and waste removal ratio,are often conflicting.A thorough understanding of the relationship among these three conflicting objectives can be greatly helpful to assist in optimal operation of MFC *** this study,a multiobjective genetic algorithm is used to simultaneously maximizing power density,attainable current density and waste removal ratio based on a mathematical model for an acetate two-chamber ***,the level diagrams method is utilized to aid in graphical visualization of Pareto front and decision *** biobjective optimization problems and one three-objective optimization problem are thoroughly *** obtained Pareto fronts illustrate the complex relationships among these three objectives,which is helpful for final decision ***,the integrated methodology of a multi-objective genetic algorithm and a graphical visualization technique provides a promising tool for the optimal operation of MFCs by simultaneously considering multiple conflicting objectives.

关键词： Microbial fuel cell Multi-objective optimization Genetic algorithm Level diagrams Pareto front

Cytocompatibility and Hemolysis of AZ31B Magnesium Alloy with Si-containing Coating

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Journal of Materials Science & Technology 2015年第8期31卷 845-851页

作者： Qiang Wang Lili Tan ke yang School of Stomatology China Medical University Institute of Metal Research Chinese Academy of Sciences

In the present study, a Si-containing coating was fabricated on AZ31B Mg alloy. Cytocompatibility of the coated alloy was evaluated by both indirect and direct contact methods, respectively. Effects of a number of incubation variables on the sensitivity and reproducibility of the hemolysis test were also examined by using positively and negatively responding biomaterials. Cytocompatibility testing results indicated that cell condition, cell adherence, cell proliferation and extracellular matrix secretion of the coated alloy were improved compared with those of the uncoated alloy for different extraction and co-culture time. The hemolysis test suggested that hemolysis testing conditions were critical to determine the hemolysis of the alloy. It was also found that 1 day in vitro degradation of the uncoated AZ31B alloy had no destructive effect on erythrocyte. As for the coated AZ31B alloy at any time point, the hemolysis rate was much lower than 5%, the safe value for biomaterials. These in vitro experimental results indicate that the Si-containing coating is effective to improve the cytocompatibility and hemolysis behaviors of AZ31B alloy during its degradation.

关键词： Magnesium alloys Biodegradable Cytocompatibility Hemolysis

Surface Modification on Biodegradable Magnesium Alloys as Orthopedic Implant Materials to Improve the Bio-adaptability:A Review

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Journal of Materials Science & Technology 2016年第9期32卷 827-834页

作者： Peng Wan Lili Tan ke yang Institute of Metal Research Chinese Academy of Sciences

Magnesium （Mg） and its alloys as a novel kind of biodegradable material have attracted much funda- mental research and valuable exploration to develop its clinical application, Mg alloys degrade too fast at the early stage after implantation, thus commonly leading to some problems such as osteolysis, early fast mechanical loss, hydric bubble aggregation, gap formation between the implants and the tissue. Surface modification is one of the effective methods to control the degradation property of Mg alloys to adapt to the need of organism. Some coatings with bioactive elements have been developed, especially for the micro-arc oxidation coating, which has high adhesion strength and can be added with Ca, P, and Sr elements. Chemical deposition coating including bio-mimetic deposition coating, electro-deposition coating and chemical conversion coating can provide good anticorrosion property as well as better bioactivity with higher Ca and P content in the coating. From the biodegradation study, it can be seen that surface coating protected the Mg alloys at the early stage providing the Mg alloy substrate with lower degra-dation rate. The biocompatibility study showed that the surface modification could provide the cell and tissue stable and weak alkaline surface micro-environment adapting to the cell adhesion and tissue growth. The surface modification also decreased the mechanical loss at the early stage adapting to the load- bearing requirement at this stage. From the interface strength between Mg alloys implants and the surrounding tissue study, it can be seen that the surface modification improved the bio-adhesion of Mg alloys with the surrounding tissue, which is believed to be contributed to the tissue adaptability of the surface modification. Therefore, the surface modification adapts the biodegradable magnesium alloys to the need of hiodegradation, biocompatibility and mechanical loss property. For the different clinical application, different surface modificatio

关键词： Bio-adaptability Coating Biodegradable Magnesium alloys Orthopedic implants