21-4N(5Cr21Mn9Ni4N)is extensively employed in the production of engine valves,operating under severe conditions.Apart from withstanding high-temperature gas corrosion,it must also endure the impact of cylinder explosi...21-4N(5Cr21Mn9Ni4N)is extensively employed in the production of engine valves,operating under severe conditions.Apart from withstanding high-temperature gas corrosion,it must also endure the impact of cylinder explosion pressure.The predominant failure mode of 21-4N valves is abrasive wear.Surface coatings serve as an effective approach to prevent such failures.In this investigation,Laser cladding technology was utilized to fabricate AlCoCrFeNiTi high entropy alloy coatings onto the surfaces of 21-4N valves.According to the findings,the cladding zone has a normal dendritic microstructure,a good substrate-to-cladding layer interaction,and no obvious flaws.In terms of hardness,the cladding demonstrates an average hardness of 620 HV.The hardness has increased by 140%compared to the substrate.The average hardness of the cladding remains at approximately 520 HV even at elevated temperatures.Regarding frictional wear performance,between 400℃and 800℃,the cladding layer exhibits an average friction coefficient of 0.4,with the primary wear mechanisms being abrasive wear,adhesive wear,and a minor degree of plastic deformation.展开更多
The authors have retracted this article [1]. After the publication ofthis article, it came to the authors attention that in order tosupport the conclusions of the study, the authors should haveused primary T cells ins...The authors have retracted this article [1]. After the publication ofthis article, it came to the authors attention that in order tosupport the conclusions of the study, the authors should haveused primary T cells instead of T cell lines. Additionally, there areconcerns that the flow cytometry methodology applied here wasflawed. These points resulted in the conclusions being consideredinvalid.展开更多
It is imperative to develop multifunctional erosion and corrosion resistant coatings for compressor blades of aircraft engines in harsh environment.PVD(Physical Vapor Deposition)technology has the advances in processi...It is imperative to develop multifunctional erosion and corrosion resistant coatings for compressor blades of aircraft engines in harsh environment.PVD(Physical Vapor Deposition)technology has the advances in processing erosion-resistant coatings;however,the performance of PVD coatings to combat corrosion depends on various coating defects.Determining and comparing the corrosion performances of PVD TiN/Ti coating and uncoated TC4 alloy was the main objective of present work.The 960 h salt spray corrosion and 116 h hot corrosion tests were conducted to simulate the grounding and working environments of the aircraft compressors.The corrosion mechanisms due to the coating defects such as pinhole,columnar boundary and large grain were analyzed based on the OM,Confocal microscope,electrochemical measurements,SEM,XRD and EDS results.Owing to the disordered state associated with the columnar boundary and the coating defect,nitrogen could be easily replaced by oxygen in the hot corrosion process,these structures were channels for fast diffusion of oxygen.Moreover,the Gibbs energy changes of Ti oxidation and TiN oxidation were thermodynamically calculated according to the working condition of aircraft compressors,and considerable research effort was focused on mapping out the phase diagram of Ti,TiN and high pressure gases.The findings of this research can provide insights into developing multifunctional coatings for future aircraft engines.展开更多
The authors have retracted this article1.After the publication of this article,it came to the authors attention that in order to support the conclusions of the study,the authors should have used primary T cells instea...The authors have retracted this article1.After the publication of this article,it came to the authors attention that in order to support the conclusions of the study,the authors should have used primary T cells instead of T-cell lines.In addition,there are concerns that the flow cytometry methodology applied here was flawed.These points resulted in the conclusions being considered invalid.展开更多
Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2...Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2))as an A1‐level,safe,and efficient disinfectant.In this study,we tested the efficacy of ClO_(2),in aqueous solution and gas forms,against avian influenza A(H7N9)virus.The virus suspension was mixed with ClO_(2) aqueous solutions of various concentrations and for various time intervals.Aliquots of the mixture were then serially diluted,and the 50%tissue culture infective dose(TCID50)was measured with a hemagglutination test on MDCK cells.ClO_(2) gas produced from generators was introduced in a chamber containing the virus suspension in a Petri dish.The infective activity of the surviving virus was measured by the hemagglutination test.An aqueous solution of ClO_(2) at 126μg/mL for 15 s was effective given that no surviving virus was detected with the hemagglutination test.ClO_(2) gas at>5μL/L sustained for 1 h inactivated the virus effectively,while at 2.5μL/L for 1 h,it only partially inactivated the virus.ClO_(2) as gas or aqueous solution at a certain concentration is effective in inactivating the H7N9 virus,and can be applied for the decontamination and disinfection of environments.展开更多
基金Sponsored by the Project to Enhance the Innovative Capabilities of Science and Technology SMEs of Shandong Province(Grant No.2023TSGC0531).
文摘21-4N(5Cr21Mn9Ni4N)is extensively employed in the production of engine valves,operating under severe conditions.Apart from withstanding high-temperature gas corrosion,it must also endure the impact of cylinder explosion pressure.The predominant failure mode of 21-4N valves is abrasive wear.Surface coatings serve as an effective approach to prevent such failures.In this investigation,Laser cladding technology was utilized to fabricate AlCoCrFeNiTi high entropy alloy coatings onto the surfaces of 21-4N valves.According to the findings,the cladding zone has a normal dendritic microstructure,a good substrate-to-cladding layer interaction,and no obvious flaws.In terms of hardness,the cladding demonstrates an average hardness of 620 HV.The hardness has increased by 140%compared to the substrate.The average hardness of the cladding remains at approximately 520 HV even at elevated temperatures.Regarding frictional wear performance,between 400℃and 800℃,the cladding layer exhibits an average friction coefficient of 0.4,with the primary wear mechanisms being abrasive wear,adhesive wear,and a minor degree of plastic deformation.
文摘The authors have retracted this article [1]. After the publication ofthis article, it came to the authors attention that in order tosupport the conclusions of the study, the authors should haveused primary T cells instead of T cell lines. Additionally, there areconcerns that the flow cytometry methodology applied here wasflawed. These points resulted in the conclusions being consideredinvalid.
基金supported by National Science and Technology Major Project of China(2017-VII-0012-0107)National Natural Science Foundation of China(No.51405506)Natural Science Basic Research Plan in Shaanxi Province of China(No.2019JQ-309)。
文摘It is imperative to develop multifunctional erosion and corrosion resistant coatings for compressor blades of aircraft engines in harsh environment.PVD(Physical Vapor Deposition)technology has the advances in processing erosion-resistant coatings;however,the performance of PVD coatings to combat corrosion depends on various coating defects.Determining and comparing the corrosion performances of PVD TiN/Ti coating and uncoated TC4 alloy was the main objective of present work.The 960 h salt spray corrosion and 116 h hot corrosion tests were conducted to simulate the grounding and working environments of the aircraft compressors.The corrosion mechanisms due to the coating defects such as pinhole,columnar boundary and large grain were analyzed based on the OM,Confocal microscope,electrochemical measurements,SEM,XRD and EDS results.Owing to the disordered state associated with the columnar boundary and the coating defect,nitrogen could be easily replaced by oxygen in the hot corrosion process,these structures were channels for fast diffusion of oxygen.Moreover,the Gibbs energy changes of Ti oxidation and TiN oxidation were thermodynamically calculated according to the working condition of aircraft compressors,and considerable research effort was focused on mapping out the phase diagram of Ti,TiN and high pressure gases.The findings of this research can provide insights into developing multifunctional coatings for future aircraft engines.
文摘The authors have retracted this article1.After the publication of this article,it came to the authors attention that in order to support the conclusions of the study,the authors should have used primary T cells instead of T-cell lines.In addition,there are concerns that the flow cytometry methodology applied here was flawed.These points resulted in the conclusions being considered invalid.
基金The study was supported by the National Science and Technology Major Project(NSTMP)for the Prevention and Treatment of Infectious Diseases(2018ZX10734401,2018ZX10301208)NSTMP for the Development of Novel Drugs(2019ZX09721001)+1 种基金Health policy research project of Shanghai Health Commission(2021HP05)This work was supported by Taiko Pharmaceutical Co.,Ltd.
文摘Avian influenza remains a threat to human wellbeing.Hypochlorite derivatives are commonly used as disinfectants to prevent the spread of the disease.The World Health Organization(WHO)has listed chlorine dioxide(ClO_(2))as an A1‐level,safe,and efficient disinfectant.In this study,we tested the efficacy of ClO_(2),in aqueous solution and gas forms,against avian influenza A(H7N9)virus.The virus suspension was mixed with ClO_(2) aqueous solutions of various concentrations and for various time intervals.Aliquots of the mixture were then serially diluted,and the 50%tissue culture infective dose(TCID50)was measured with a hemagglutination test on MDCK cells.ClO_(2) gas produced from generators was introduced in a chamber containing the virus suspension in a Petri dish.The infective activity of the surviving virus was measured by the hemagglutination test.An aqueous solution of ClO_(2) at 126μg/mL for 15 s was effective given that no surviving virus was detected with the hemagglutination test.ClO_(2) gas at>5μL/L sustained for 1 h inactivated the virus effectively,while at 2.5μL/L for 1 h,it only partially inactivated the virus.ClO_(2) as gas or aqueous solution at a certain concentration is effective in inactivating the H7N9 virus,and can be applied for the decontamination and disinfection of environments.
基金supported by the National Science and Technology Major Project(NSTMP)for the Prevention and Treatment of Infectious Diseases(2018ZX10734401,2018ZX10301208)the NSTMP for the Development of Novel Drugs(2019ZX09721001)the Project of Novel Coronavirus Research of Fudan University,China Postdoctoral Science Foundation(2020T130016ZX)。
