Joining dissimilar materials encounters significant engineering challenges due to the contrast in material properties that makes conventional welding not feasible.Magnetic Pulse Welding(MPW)offers a solidstate joining...Joining dissimilar materials encounters significant engineering challenges due to the contrast in material properties that makes conventional welding not feasible.Magnetic Pulse Welding(MPW)offers a solidstate joining technique that overcomes these issues by using impact to create strong bonds without melting the substrate materials.This study investigates the weldability of aluminum alloy Al-5754 with Al-7075 and MARS 380 steel,used in armouring solutions of defense systems,by the use of MPW.In this work,weldability windows are investigated by varying standoff distances between the coating material and its substrate(0.25-4.5 mm)and discharge energies(5-13 kJ)with both O-shape and U-shape inductors.Mechanical strength of the welded joints were assessed through single lap shear tests,identifying optimal welding parameters.Then,the velocity profiles of the flyer plates were measured using heterodyne velocimetry to understand the dynamics of the impact.Then,substructures assembled with the optimal welding conditions were subjected to ballistic testing using 7.62 mm×51 mm NATO and 9 mm×19 mm Parabellum munitions to evaluate the resilience of the welds under ballistic impact.The outcomes demonstrate that MPW effectively joins Al-5754 with both Al-7075 and MARS 380,producing robust welds capable of withstanding ballistic impacts under certain conditions.This research advances the application of MPW in lightweight ballistic protection of defense systems,contributing to the development of more resilient and lighter protective structures.展开更多
To improve the corrosion resistance of biodegradable Mg alloys,WE43 alloys were implanted with Fe,Ti,Zn and Zr ions at the same implantation dose.The surface morphology,valence state of elements,nano-hardness(NH),elas...To improve the corrosion resistance of biodegradable Mg alloys,WE43 alloys were implanted with Fe,Ti,Zn and Zr ions at the same implantation dose.The surface morphology,valence state of elements,nano-hardness(NH),elastic modulus(EM),degradation rate and in vitro cell experiments of the modified WE43 alloys were systematically studied.A modified layer composed of Mg,MgO,the implanted elements and their oxides was formed on the modified alloys.Since high-speed metal ions caused severe surface lattice damage,the surface hardness of the substrate considerable increased.Electrochemical tests demonstrated a substantial enhancement in the corrosion resistance of the modified alloys via the implantation of Ti and Zr ions,resulting in a reduction of the corrosion current density to 88.1±9.9 and 15.6±11.4μA cm^(−2),respectively,compared with the implantation of Fe and Zn ions.Biocompatibility tests showed that the implantation of Fe,Ti,Zn and Zr ions enhanced the anticoagulant and hemolytic resistance of the WE43 alloy.All surface-modified samples showed negligible cytotoxicity(0-1)at 12.5%extract concentration.Moreover,the alloys implanted with Fe,Ti and Zn ions significantly promoted proliferation of human umbilical vein endothelial cells(HUVEC)compared with the unmodified alloy.The results demonstrate that Ti ion implantation is the best choice for WE43 alloy modification to achieve outstanding corrosion resistance and biocompatibility.展开更多
Advances in the identification of molecular biomarkers and the development of targeted therapies have enhanced the prognosis of patients with advanced gastric cancer.Several established biomarkers have been widely int...Advances in the identification of molecular biomarkers and the development of targeted therapies have enhanced the prognosis of patients with advanced gastric cancer.Several established biomarkers have been widely integrated into routine clinical diagnostics of gastric cancer to guide personalized treatment.Human epidermal growth factor receptor 2(HER2)was the first molecular biomarker to be used in gastric cancer with trastuzumab being the first approved targeted therapy for HER2-positive gastric cancer.Programmed death-ligand 1 positivity and microsatellite instability can guide the use of immunotherapies,such as pembrolizumab and nivolumab.More recently,zolbetuximab has been approved for patients with claudin 18.2-positive diseases in some countries.More targeted therapies,including savolitinib for MET-positive patients,are currently under clinical investigation.However,the clinical application of these diagnostic approaches could be hampered by many existing challenges,including invasive and costly sampling methods,variability in immunohistochemistry interpretation,high costs and long turnaround times for next-generation sequencing,the absence of standardized and clinically validated diagnostic cut-off values for some biomarkers,and tumor heterogeneity.Novel testing and analysis techniques,such as artificial intelligence-assisted image analysis and multiplex immunohistochemistry,and emerging therapeutic strategies,including combination therapies that integrate immune checkpoint inhibitors with targeted therapies,offer potential solutions to some of these challenges.This article reviews recent progress in gastric cancer testing,outlines current challenges,and explores future directions for biomarker testing and targeted therapy for gastric cancer.展开更多
The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail ...The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail inspection methods,specifically involving real-time,precise detection,and assessment of rail defects.Current applications fail to address the evolving requirements,prompting the need for advancements.This paper provides a summary of various types of rail defects and outlines both traditional and innovative non-destructive inspection techniques,examining their fundamental features,benefits,drawbacks,and practical suitability for railway track inspection.It also explores potential enhancements to equipment and software.The comprehensive review draws upon pertinent international research and review papers.Furthermore,the paper introduces a fusion of inspection methods aimed at enhancing the overall reliability of defect detection.展开更多
Accurate macaque paternity identification is of great significance in various fields,yet relevant research remains scarce.Our study aimed to screen effective microsatellite markers for macaque paternity testing.Initia...Accurate macaque paternity identification is of great significance in various fields,yet relevant research remains scarce.Our study aimed to screen effective microsatellite markers for macaque paternity testing.Initially,300 microsatellite markers were randomly selected from the genome of the crab-eating macaque(Macaca fascicularis),and 12 highly polymorphic tetra-nucleotide repeat markers were identified.These markers'genetic parameters and exclusion probabilities in both crab-eating and rhesus macaque(Macaca mulatta)populations were calculated,meeting the paternity testing requirements for both species.To validate the markers,16 crab-eating macaque and 10 rhesus macaque families with known pedigrees were randomly chosen for testing.The genotypes of the 12 markers in the macaques'offspring could be traced back to their parents,confirming the accuracy and applicability of the marker combination for paternity identification in both macaque species.展开更多
The purpose of this study is to analyze the application of ultrasonic non-destructive testing technology in bridge engineering.During the research phase,based on literature collection and reading,as well as the analys...The purpose of this study is to analyze the application of ultrasonic non-destructive testing technology in bridge engineering.During the research phase,based on literature collection and reading,as well as the analysis of bridge inspection materials,the principle of ultrasonic non-destructive testing technology and its adaptability to bridge engineering are elaborated.Subsequently,starting from the preparation work before inspection until damage assessment,the entire process of ultrasonic non-destructive testing is studied,and finally,a technical system of ultrasonic non-destructive testing for bridge engineering that runs through the entire process is formed.It is hoped that this article can provide technical reference value for relevant units in China,and promote the high-quality development of China’s bridge engineering from a macro perspective.展开更多
With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist i...With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist in the field testing methodologies for wave energy converters(WECs).In this paper,a numerical wave field of the Dawanshan Island Sea Area in Zhuhai City is constructed based on the MIKE21 SW wave model and by using an NCEP wind field driving model.In conjunction with the IEC-62600-100 standard,by taking site testing of the“Wanshan”wave energy converter on which a sea trial has been conducted in Dawanshan Island of Zhuhai city as an example,research on-site testing method for a wave energy converter has been carried out.The wave measurement position for the“Wanshan”converter was determined by combining statistically analyzed field data with a validated numerical wave model.By comparing a valid wave height at the position where a wave rider is located with a valid wave height at the position where the“Wanshan”wave energy converter is situated,the correlation coefficient between simulation and observed data reached 0.90,with a root-mean-square error of 0.19.The representativeness of wave measurement data during site testing is verified and can be used as a basis for calculating the input energy of the“Wanshan”wave energy converter.展开更多
Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the su...Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the substantial pressures exerted by vehicles,trains,and other forms of transportation,but also efficiently transfer these loads to the underlying foundation,ensuring the stability and longevity of the roadway.In recent years,advancements in subgrade engineering technology have propelled the industry towards smarter,greener,and more sustainable practices,particularly in the areas of intelligent monitoring,disaster management,and innovative construction methods.This paper reviews the application and methodologies of intelligent testing equipment,including cone penetration testing(CPT)devices,soil resistivity testers,and intelligent rebound testers,in subgrade engineering.It examines the operating principles,advantages,limitations,and application ranges of these tools in subgrade testing.Additionally,the paper evaluates the practical use of advanced equipment from both domestic and international perspectives,addressing the challenges encountered by various instruments in realworld applications.These devices enable precise,comprehensive testing and evaluation of subgrade conditions at different stages,providing real-time data analysis and intelligent early warnings.This supports effective subgrade health management and maintenance.As intelligent technologies continue to evolve and integrate,these tools will increasingly enhance the accuracy,efficiency,and sustainability of subgrade monitoring.展开更多
In this study,the effect of annealing on the microstructure and following corrosion and biological properties of Mg-1.0Ca-0.5Zn-0.1Y-0.03Mn(at.%)alloy prepared by rapid solidified powder metallurgy was investigated.Th...In this study,the effect of annealing on the microstructure and following corrosion and biological properties of Mg-1.0Ca-0.5Zn-0.1Y-0.03Mn(at.%)alloy prepared by rapid solidified powder metallurgy was investigated.The annealing at 300℃ for 2 h did not change the grain size significantly;however,a slight growth of Mg_(2)Ca precipitates was observed.When the annealing temperature increased up to 400℃ for 2 h,full recrystallization of the alloy occurred;the grains and precipitates grew noticeably.Those changes were responsible for decreasing the corrosion and the tribocorrosion resistance of the alloy.Due to lowered resistance to the corrosion medium,the cell viability was also reduced.Although MG63 cells on the annealed specimens developed filopodia,cell-to-cell communication was not observed.展开更多
Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by...Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by using portable diagnostic devices,avoiding sending samples to the medical laboratories.It has been extensively explored for diagnosing and monitoring patients’diseases and health conditions with the assistance of development in biochemistry and microfluidics.Microfluidic paper-based analytical devices(μPADs)have gained dramatic popularity in POCT because of their simplicity,user-friendly,fast and accurate result reading and low cost.SeveralμPADs have been successfully commercialized and received excellent feedback during the past several decades.This review briefly discusses the main types ofμPADs,preparation methods and their detection principles,followed by a few representative examples.The future perspectives of the development inμPADs are also provided.展开更多
To address the limited wear resistance observed in traditional titanium alloys,we have developed an ultrafine-grained equiatomic TiMoNb compositionally complex alloy(CCA)with exceptional wear resistance.However,there ...To address the limited wear resistance observed in traditional titanium alloys,we have developed an ultrafine-grained equiatomic TiMoNb compositionally complex alloy(CCA)with exceptional wear resistance.However,there is a significant lack of in vitro and in vivo evaluation of the TiMoNb CCA for biomedical applications.In this study,we comprehensively evaluate the corrosion behavior,tribo-corrosion performance,biocompatibility,and osseointegration of the TiMoNb alloy.Our findings indicate that the alloy exhibits strong corrosion resistance and stable tribo-corrosion behavior,attributed to the presence of Ti-rich nanoscale precipitates that impede tribo-corrosion-induced shear deformation,along with a protective nanoscale oxide layer.Furthermore,in vitro and in vivo evaluations demonstrate the excellent biocompatibility of the TiMoNb alloy and reveal its ability to promote the regeneration of defective femurs and its favorable bone osseointegration capability.Overall,our study underscores the potential of the TiMoNb alloy as a promising material for dental implants and provides valuable insights into the tribo-corrosion mechanisms of ultrafine-grained alloys.展开更多
Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant...Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant on traditional laptops and computers, which, while portable, lack true ultra-portability. This paper explores the potential impact of developing a dedicated, ultra-portable, low-cost device for on-the-go penetration testing. Such a device could replicate the core functionalities of advanced penetration testing tools, including those found in Kali Linux, within a compact form factor that fits easily into a pocket. By offering the convenience and portability akin to a smartphone, this innovative device could redefine the way penetration testers operate, enabling them to carry essential tools wherever they go and ensuring they are always prepared to conduct security assessments efficiently. This approach aims to revolutionize penetration testing by merging high functionality with unparalleled portability.展开更多
Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are ...Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are attractive at different scales.Each method requires minimal sample volume,is low cost,and includes a relatively rapid measurement turnaround time.However,recent micro-scale test results–including scratch test results and nanoindentation results–exhibit tangible variance and uncertainty,suggesting a need to correlate mineral composition mapping to elastic modulus mapping to isolate the relative impact of specific minerals.Different research labs often utilize different interpretation methods,and it is clear that future micro-mechanical tests may benefit from standardized testing and interpretation procedures.The objectives of this study are to seek options for standardized testing and interpretation procedures,through two specific objectives:(1)Quantify chemical and physical controls on micro-mechanical properties and(2)Quantify the source of uncertainties associated with nanoindentation measurements.To reach these goals,we conducted mechanical tests on three different scales:triaxial compression tests,scratch tests,and nanoindentation tests.We found that mineral phase weight percentage is highly correlated with nanoindentation elastic modulus distribution.Finally,we conclude that nanoindentation testing is a mineralogy and microstructure-based method and generally yields significant uncertainty and overestimation.The uncertainty of the testing method is largely associated with not mapping pore space a priori.Lastly,the uncertainty can be reduced by combining phase mapping and modulus mapping with substantial and random data sampling.展开更多
The possible application of magnesium(Mg)in glaucoma surgical treatment has been investigated in our previous work.In this paper,the degradation behavior and biocompatibility of Mg coated with hydroxyapatite(HA)and di...The possible application of magnesium(Mg)in glaucoma surgical treatment has been investigated in our previous work.In this paper,the degradation behavior and biocompatibility of Mg coated with hydroxyapatite(HA)and dicalcium phosphate dihydrate(DCPD)in eye environment were evaluated,and uncoated Mg was used for comparison.It was found that uniform corrosion occurred macroscopically to the coated Mg samples in sodium lactate ringer’s injection(SLRI)as well as in the rabbit eyes.In micro-scale,the corrosion was characterized by local cracking and pitting primarily.Mg and calcium(Ca)were incorporated into the surface corrosion products and a multi-layer structure was formed.Compared to other samples,HA-coated Mg slowed down dramatically the alkalinity of the solution and the ion release of the sample,and exhibited the lowest corrosion rate in SLRI,which was about 0.22 mm/a.In terms of biocompatibility,fibroblasts demonstrated high viability in the HA-coated and DCPD-coated Mg groups(p<0.05)in vitro.In vivo,HA-coated Mg was found to show lower inflammatory response and fibrosis than the other groups did,as indicated by hematoxylin-eosin and immunofluorescence staining.During the degrading process of HA-coated Mg in the rabbits’eyes,no inflammation was found in the anterior chamber,lens,and vitreous body.HA-coated Mg was fully biodegraded fifteen weeks post-operation,and the scleral drainage channel(SDC)was formed without obvious scarring.It is concluded that HA-coated Mg implantation is a promising adjunctive procedure to improve the success rate of trabeculectomy.Statement of significance:Magnesium(Mg)has shown to be a potential biomaterial for ophthalmic implants in our previous work.However,inflammatory response resulted from the low corrosion resistance of Mg is a major concern.It is shown here that Mg coated with different calcium phosphates can improve these properties in varying degrees and keep the scleral drainage channel unobstructed and unscarred.Based on our in vitro and in vivo studies,HA-coated Mg exhibited a better degradation behavior and excellent biocompatibility.The scleral drainage channel still exists and aqueous humor flows out smoothly after the full degradation of the implant.It is concluded that HA-coated Mg is a promising biomaterial to increase the therapeutic efficiency of trabeculectomy for glaucoma.展开更多
Although the degradability and biosafety of magnesium alloys make them advantageous for biological applications,medical implants made of magnesium alloys often fail prematurely due to corrosion.Therefore,improving the...Although the degradability and biosafety of magnesium alloys make them advantageous for biological applications,medical implants made of magnesium alloys often fail prematurely due to corrosion.Therefore,improving the corrosion resistance of magnesium alloys has become an urgent problem in the alloy design process.In this study,we designed and prepared Mg-xZn-0.5Y-0.5Zr(x=1,2,and 3,wt%)alloys in a hot extruded state and analyzed their surface structure through scanning electron microscopy,energy dispersion spectrometry,and X-ray diffraction.It was found that increasing the Zn content refined the recrystallized grains in the alloy.Particularly in Mg-3Zn-0.5Y-0.5Zr,the I phase became finer,forming both granular and nanoscale needle-like particles.Surface characterization after the immersion experiment showed that the corrosion product layer was mainly composed of Mg(OH)_(2),Zn(OH)_(2),CaCO_(3),and hy-droxyapatite.The degradation rate of ZW305K was the lowest,measured as 4.1 and 6.0 mm·a^(-1) with the hydrogen precipitation method and weight loss method respectively.Electrochemical experiments further explained the corrosion circuit model of the alloy in solution and confirmed the earlier results.The maximum polarization resistance of ZW305K was 874.5Ω·cm^(2),and the lowest corrosion current density was 0.104 mA·cm^(-2).As a biomedical alloy,it must exhibit good biocompatibility,so the alloy was also tested through cytotoxicity,cell adhesion,and staining experiments.The cell viability of each group after 48 h was greater than 80%,showing that the addition of zinc enhances the alloy’s biocompatibility.In summary,the prepared alloys have the potential to be used as biodegradable implant materials.展开更多
The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSN...The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSNS-II)commenced in 2024.The CSNS-II linac design primarily involves the addition of a radio-frequency ion source and a section of a superconducting linear accelerator composed of two types of superconducting cavities,namely double-spoke and six-cell elliptical cavities,after the drift tube linac(DTL).The development of the double-spoke superconducting cavity began in early 2021,and by January 2023,the welding,post-processing,and vertical tests of two 324 MHz double-spoke cavity prototypes were completed,with vertical test gradients of 11.6 and 15 MV/m,and Q_(0)≥3×10^(10)@E_(acc)≤10 MV/m.The R&D of the cryomodule began in January 2022.In October 2023,the clean assembly of the double-spoke cavity string and cold mass installation of the cryomodule commenced,with the installation of the cryomodule and valve box completing in two months.In January 2024,a horizontal test of the cryomodule was completed,making it the first double-spoke cavity cryomodule in China.The test results showed that the maximum gradients of the two superconducting cavities at a pulse width of 4 ms and repetition frequency of 25 Hz were 12.8 and 15.2 MV/m,respectively.This article provides a detailed introduction to the double-spoke superconducting cavity,tuner,coupler,and cryomodule,elaborates on the clean assembly of the cavity string and cold mass installation of the cryomodule,and provides a detailed analysis of the horizontal test results.展开更多
Previous work indicated that long-period stacking ordered(LPSO) phase and/or γ’ in rare earth containing Mg biomaterials had contradictory mechanisms responsible for their degradation in less complex or standard sal...Previous work indicated that long-period stacking ordered(LPSO) phase and/or γ’ in rare earth containing Mg biomaterials had contradictory mechanisms responsible for their degradation in less complex or standard salt media, such as 0.9 % NaCl solution. They needed to be further investigated in a more realistic simulated body fluid(SBF). The present work investigated the influence of the amount and types of intermetallics on the degradation behavior of as-cast Mg-xDy-Zn(x = 5, 10, 15 wt.%) alloys using immersion test in Dulbecco's modified Eagle's medium(DMEM) + Glutamax together with 10 % Fetal bovine serum(FBS) under cell culture conditions. It was revealed that the existence of intermetallics exhibited different effects on the degradation behavior of alloys. At the early stage of immersion, Mg-10Dy-1.5Zn alloy suffered the most serious degradation among these three alloys, owing to its more severe micro galvanic corrosion. With the immersion proceeding, the degradation rate of Mg-5Dy-1.5Zn alloy consistently increased because of the scattered distribution of few intermetallics. In contrast, the continuous network structure of intermetallics and a compact degradation layer provided protection from further degradation for Mg-10Dy-1.5Zn and Mg-15Dy-1.5Zn alloys. In the as-cast Mg-5Dy-1.5Zn alloy, only small amount of intermetallics composed of W, γ’ and18R LPSO phases acted as galvanic cathodes, accelerating its degradation. With Dy content increasing to 10 and 15 wt.%, large amounts of intermetallics including 18R LPSO and dense γ’ phases were formed, which on the other hand can serve as a continuous network barrier to retard degradation propagation. Finally, the good adhesion and proliferation of the Human umbilical cord perivascular(HUCPV) on the surface of the Mg-10Dy-1.5Zn and Mg-15Dy-1.5Zn alloy indicated their good biocompatibility.展开更多
Knowledge of the dynamic modulus of bituminous mixtures is practical and theoretically meaningful in pavement design,construction,and monitoring.The tests in the laboratory for the determination of asphalt concrete(AC...Knowledge of the dynamic modulus of bituminous mixtures is practical and theoretically meaningful in pavement design,construction,and monitoring.The tests in the laboratory for the determination of asphalt concrete(AC)moduli include the resilient modulus through the indirect tensile test(EN 12697-26),the complex modulus through the four point bending beam(EN 12697-26),the asphalt mixture performance tester(AMPT)and the simple performance tester(SPT)(AASHTO T342).Unfortunately,the tests above are time-consuming and quite expensive.On the other hand,the standard ASTM E1876 for resonant tests applies only to very thin(stocky)cylindrical samples(with a thickness-to-radius ratio,t/r,lower than 0.5)while the typical AC samples produced in the laboratory do not satisfy the ASTM E1876 requirements.Consequently,the main objective of this study is to set up and implement a tentative method to extend the range of applicability of the standard ASTM E1876 to common AC samples.The methodology was to carry out resonant tests on slender samples and to cut each of them into stocky samples(these latter complying with ASTM E1876 requirements in terms of t/r),deriving the master curve per material.These master curves allowed for deriving the value of the dynamic modulus for the given selected sample under its particular test conditions during the resonant test(i.e.,temperature and frequency).Consequently,simplified formulae were provided for AC samples.Results were compared to Witczak's estimates.These formulae provide an approximate tool to carry out low-cost and high-speed inferences at the laboratory stage on common AC samples,whatever their thickness is.Additional studies are needed to investigate the reliability of the method further and reduce uncertainties.展开更多
In recent years,the application scenarios of electrical and electronic products have become increasingly diverse worldwide.The impact of climatic environmental tests on the performance of related products has attracte...In recent years,the application scenarios of electrical and electronic products have become increasingly diverse worldwide.The impact of climatic environmental tests on the performance of related products has attracted much attention,and formulating scientific and reasonable environmental test plans has become an important step to ensure product quality and reliability.展开更多
Utilizing nanotechnology and composites to create a protective film on titanium alloy is an effective means of achieving the desired high performance.Self-assembly of nanocomposite structures offers a promising route ...Utilizing nanotechnology and composites to create a protective film on titanium alloy is an effective means of achieving the desired high performance.Self-assembly of nanocomposite structures offers a promising route to forming high entropy alloy films(HEAFs),but controlled preparation remains challeng-ing.This work used magnetron sputtering through adjusting preparation parameters to prepare ZrNbTi-CrCu HEAFs,achieving a significant improvement in corrosion resistance and biocompatibility induced by the precipitation of Cu.According to the electrochemical corrosion test,without obvious corrosion pits on the surface of S2 after corrosion,a passivation film composed of bimetallic oxide CuCrO2 formed on the film surface,indicating that ZrNbTiCrCu HEAFs have remarkable corrosion resistance performance.In the cytocompatibility experiment,the cell viability of HEAFs reached over 95%due to the precipitation of Cu,suggesting their excellent biocompatibility.In addition,ZrNbTiCrCu HEAFs exhibit outstanding an-tibacterial ability,especially when the sputtering current is 0.6 A,and the in vitro antibacterial rate of the sample against Escherichia coli is close to 99%.展开更多
基金funded on the one hand by Agence de l'Innovation de Défense(AID)grant reference number 2021650044on the other hand by Ecole Centrale de Nantes。
文摘Joining dissimilar materials encounters significant engineering challenges due to the contrast in material properties that makes conventional welding not feasible.Magnetic Pulse Welding(MPW)offers a solidstate joining technique that overcomes these issues by using impact to create strong bonds without melting the substrate materials.This study investigates the weldability of aluminum alloy Al-5754 with Al-7075 and MARS 380 steel,used in armouring solutions of defense systems,by the use of MPW.In this work,weldability windows are investigated by varying standoff distances between the coating material and its substrate(0.25-4.5 mm)and discharge energies(5-13 kJ)with both O-shape and U-shape inductors.Mechanical strength of the welded joints were assessed through single lap shear tests,identifying optimal welding parameters.Then,the velocity profiles of the flyer plates were measured using heterodyne velocimetry to understand the dynamics of the impact.Then,substructures assembled with the optimal welding conditions were subjected to ballistic testing using 7.62 mm×51 mm NATO and 9 mm×19 mm Parabellum munitions to evaluate the resilience of the welds under ballistic impact.The outcomes demonstrate that MPW effectively joins Al-5754 with both Al-7075 and MARS 380,producing robust welds capable of withstanding ballistic impacts under certain conditions.This research advances the application of MPW in lightweight ballistic protection of defense systems,contributing to the development of more resilient and lighter protective structures.
基金supported by National Natural Science Foundation of China(52271117)Educational Commission of Hunan Province of China(23A0107)High Technology Research and Development Program of Hunan Province of China(2022GK4038).
文摘To improve the corrosion resistance of biodegradable Mg alloys,WE43 alloys were implanted with Fe,Ti,Zn and Zr ions at the same implantation dose.The surface morphology,valence state of elements,nano-hardness(NH),elastic modulus(EM),degradation rate and in vitro cell experiments of the modified WE43 alloys were systematically studied.A modified layer composed of Mg,MgO,the implanted elements and their oxides was formed on the modified alloys.Since high-speed metal ions caused severe surface lattice damage,the surface hardness of the substrate considerable increased.Electrochemical tests demonstrated a substantial enhancement in the corrosion resistance of the modified alloys via the implantation of Ti and Zr ions,resulting in a reduction of the corrosion current density to 88.1±9.9 and 15.6±11.4μA cm^(−2),respectively,compared with the implantation of Fe and Zn ions.Biocompatibility tests showed that the implantation of Fe,Ti,Zn and Zr ions enhanced the anticoagulant and hemolytic resistance of the WE43 alloy.All surface-modified samples showed negligible cytotoxicity(0-1)at 12.5%extract concentration.Moreover,the alloys implanted with Fe,Ti and Zn ions significantly promoted proliferation of human umbilical vein endothelial cells(HUVEC)compared with the unmodified alloy.The results demonstrate that Ti ion implantation is the best choice for WE43 alloy modification to achieve outstanding corrosion resistance and biocompatibility.
基金support by grants from Capital’s Funds for Health Improvement and Research(Grant No.2024-2-1024)Beijing Natural Science Foundation(Grant No.7232018).
文摘Advances in the identification of molecular biomarkers and the development of targeted therapies have enhanced the prognosis of patients with advanced gastric cancer.Several established biomarkers have been widely integrated into routine clinical diagnostics of gastric cancer to guide personalized treatment.Human epidermal growth factor receptor 2(HER2)was the first molecular biomarker to be used in gastric cancer with trastuzumab being the first approved targeted therapy for HER2-positive gastric cancer.Programmed death-ligand 1 positivity and microsatellite instability can guide the use of immunotherapies,such as pembrolizumab and nivolumab.More recently,zolbetuximab has been approved for patients with claudin 18.2-positive diseases in some countries.More targeted therapies,including savolitinib for MET-positive patients,are currently under clinical investigation.However,the clinical application of these diagnostic approaches could be hampered by many existing challenges,including invasive and costly sampling methods,variability in immunohistochemistry interpretation,high costs and long turnaround times for next-generation sequencing,the absence of standardized and clinically validated diagnostic cut-off values for some biomarkers,and tumor heterogeneity.Novel testing and analysis techniques,such as artificial intelligence-assisted image analysis and multiplex immunohistochemistry,and emerging therapeutic strategies,including combination therapies that integrate immune checkpoint inhibitors with targeted therapies,offer potential solutions to some of these challenges.This article reviews recent progress in gastric cancer testing,outlines current challenges,and explores future directions for biomarker testing and targeted therapy for gastric cancer.
文摘The rapid progress in the construction of heavy-haul and high-speed railways has led to a surge in rail defects and unforeseen failures.Addressing this issue necessitates the implementation of more sophisticated rail inspection methods,specifically involving real-time,precise detection,and assessment of rail defects.Current applications fail to address the evolving requirements,prompting the need for advancements.This paper provides a summary of various types of rail defects and outlines both traditional and innovative non-destructive inspection techniques,examining their fundamental features,benefits,drawbacks,and practical suitability for railway track inspection.It also explores potential enhancements to equipment and software.The comprehensive review draws upon pertinent international research and review papers.Furthermore,the paper introduces a fusion of inspection methods aimed at enhancing the overall reliability of defect detection.
基金Nanhu Laboratory Self-Initiated Research Project,Grant/Award Number:NSS2023A00001-2。
文摘Accurate macaque paternity identification is of great significance in various fields,yet relevant research remains scarce.Our study aimed to screen effective microsatellite markers for macaque paternity testing.Initially,300 microsatellite markers were randomly selected from the genome of the crab-eating macaque(Macaca fascicularis),and 12 highly polymorphic tetra-nucleotide repeat markers were identified.These markers'genetic parameters and exclusion probabilities in both crab-eating and rhesus macaque(Macaca mulatta)populations were calculated,meeting the paternity testing requirements for both species.To validate the markers,16 crab-eating macaque and 10 rhesus macaque families with known pedigrees were randomly chosen for testing.The genotypes of the 12 markers in the macaques'offspring could be traced back to their parents,confirming the accuracy and applicability of the marker combination for paternity identification in both macaque species.
文摘The purpose of this study is to analyze the application of ultrasonic non-destructive testing technology in bridge engineering.During the research phase,based on literature collection and reading,as well as the analysis of bridge inspection materials,the principle of ultrasonic non-destructive testing technology and its adaptability to bridge engineering are elaborated.Subsequently,starting from the preparation work before inspection until damage assessment,the entire process of ultrasonic non-destructive testing is studied,and finally,a technical system of ultrasonic non-destructive testing for bridge engineering that runs through the entire process is formed.It is hoped that this article can provide technical reference value for relevant units in China,and promote the high-quality development of China’s bridge engineering from a macro perspective.
基金supported by the“National Ocean Technology Center Innovation Fund”under Project No.N3220Z002,led by Ning Jia.The official website of the National Ocean Technology Center is accessible at:http://www.notcsoa.org.cn/.
文摘With the depletion of fossil fuels and increasing environmental concerns,the development of renewable energy,such as wave energy,has become a critical component of global energy strategies.However,challenges persist in the field testing methodologies for wave energy converters(WECs).In this paper,a numerical wave field of the Dawanshan Island Sea Area in Zhuhai City is constructed based on the MIKE21 SW wave model and by using an NCEP wind field driving model.In conjunction with the IEC-62600-100 standard,by taking site testing of the“Wanshan”wave energy converter on which a sea trial has been conducted in Dawanshan Island of Zhuhai city as an example,research on-site testing method for a wave energy converter has been carried out.The wave measurement position for the“Wanshan”converter was determined by combining statistically analyzed field data with a validated numerical wave model.By comparing a valid wave height at the position where a wave rider is located with a valid wave height at the position where the“Wanshan”wave energy converter is situated,the correlation coefficient between simulation and observed data reached 0.90,with a root-mean-square error of 0.19.The representativeness of wave measurement data during site testing is verified and can be used as a basis for calculating the input energy of the“Wanshan”wave energy converter.
基金supported by the National Natural Science Foundation of China for Distinguished Young Scholars(Grant No.42225206)National Natural Science Foundation of China(42207180,42477209,42302320).
文摘Subgrade engineering is a fundamental aspect of infrastructure construction in China.As the primary structural element responsible for bearing and distributing traffic loads,the subgrade must not only withstand the substantial pressures exerted by vehicles,trains,and other forms of transportation,but also efficiently transfer these loads to the underlying foundation,ensuring the stability and longevity of the roadway.In recent years,advancements in subgrade engineering technology have propelled the industry towards smarter,greener,and more sustainable practices,particularly in the areas of intelligent monitoring,disaster management,and innovative construction methods.This paper reviews the application and methodologies of intelligent testing equipment,including cone penetration testing(CPT)devices,soil resistivity testers,and intelligent rebound testers,in subgrade engineering.It examines the operating principles,advantages,limitations,and application ranges of these tools in subgrade testing.Additionally,the paper evaluates the practical use of advanced equipment from both domestic and international perspectives,addressing the challenges encountered by various instruments in realworld applications.These devices enable precise,comprehensive testing and evaluation of subgrade conditions at different stages,providing real-time data analysis and intelligent early warnings.This supports effective subgrade health management and maintenance.As intelligent technologies continue to evolve and integrate,these tools will increasingly enhance the accuracy,efficiency,and sustainability of subgrade monitoring.
基金funded by the National Centre for Research and Development in Poland, project V4-JAPAN/2/15 “Development of Advanced Magnesium Alloys for Multifunctional Applications in Extreme Environments,” under statutory work at the Faculty of Material Science and Engineering Warsaw University of Technology in Polandthe International Visegrad Fund (project no. JP39421, V4Japan Joint Research Program)+3 种基金the support of the International Visegrad Fund (project V4Japan Joint Research Program, Ref. JP3936)the National Research, Development and Innovation Office (contract no. 2019-2.1.7-ERA-NET-2021-00030)Support by the Ministry of Education, Youth and Sports of the Czech Republic in the framework of Visegrad Group (V4)-Japan Joint Research Program-Advanced Materials under grant no. 8F21011 is gratefully acknowledged by K.M., D.D., and A.Fthe support from the Department of Metal and Corrosion Engineering, University of Chemical Technology, Prague, Czech Republic, while performing the tribocorrosion measurements
文摘In this study,the effect of annealing on the microstructure and following corrosion and biological properties of Mg-1.0Ca-0.5Zn-0.1Y-0.03Mn(at.%)alloy prepared by rapid solidified powder metallurgy was investigated.The annealing at 300℃ for 2 h did not change the grain size significantly;however,a slight growth of Mg_(2)Ca precipitates was observed.When the annealing temperature increased up to 400℃ for 2 h,full recrystallization of the alloy occurred;the grains and precipitates grew noticeably.Those changes were responsible for decreasing the corrosion and the tribocorrosion resistance of the alloy.Due to lowered resistance to the corrosion medium,the cell viability was also reduced.Although MG63 cells on the annealed specimens developed filopodia,cell-to-cell communication was not observed.
文摘Point-of-care testing(POCT)refers to a category of diagnostic tests that are performed at or near to the site of the patients(also called bedside testing)and is capable of obtaining accurate results in a short time by using portable diagnostic devices,avoiding sending samples to the medical laboratories.It has been extensively explored for diagnosing and monitoring patients’diseases and health conditions with the assistance of development in biochemistry and microfluidics.Microfluidic paper-based analytical devices(μPADs)have gained dramatic popularity in POCT because of their simplicity,user-friendly,fast and accurate result reading and low cost.SeveralμPADs have been successfully commercialized and received excellent feedback during the past several decades.This review briefly discusses the main types ofμPADs,preparation methods and their detection principles,followed by a few representative examples.The future perspectives of the development inμPADs are also provided.
基金financially supported by the National Natural Science Foundation of China(Nos.52371251 and 52122102)the Fundamental and Applied Fundamental Research Fund of Guangdong Province(No.2022B1515120082).
文摘To address the limited wear resistance observed in traditional titanium alloys,we have developed an ultrafine-grained equiatomic TiMoNb compositionally complex alloy(CCA)with exceptional wear resistance.However,there is a significant lack of in vitro and in vivo evaluation of the TiMoNb CCA for biomedical applications.In this study,we comprehensively evaluate the corrosion behavior,tribo-corrosion performance,biocompatibility,and osseointegration of the TiMoNb alloy.Our findings indicate that the alloy exhibits strong corrosion resistance and stable tribo-corrosion behavior,attributed to the presence of Ti-rich nanoscale precipitates that impede tribo-corrosion-induced shear deformation,along with a protective nanoscale oxide layer.Furthermore,in vitro and in vivo evaluations demonstrate the excellent biocompatibility of the TiMoNb alloy and reveal its ability to promote the regeneration of defective femurs and its favorable bone osseointegration capability.Overall,our study underscores the potential of the TiMoNb alloy as a promising material for dental implants and provides valuable insights into the tribo-corrosion mechanisms of ultrafine-grained alloys.
文摘Penetration testing plays a critical role in ensuring security in an increasingly interconnected world. Despite advancements in technology leading to smaller, more portable devices, penetration testing remains reliant on traditional laptops and computers, which, while portable, lack true ultra-portability. This paper explores the potential impact of developing a dedicated, ultra-portable, low-cost device for on-the-go penetration testing. Such a device could replicate the core functionalities of advanced penetration testing tools, including those found in Kali Linux, within a compact form factor that fits easily into a pocket. By offering the convenience and portability akin to a smartphone, this innovative device could redefine the way penetration testers operate, enabling them to carry essential tools wherever they go and ensuring they are always prepared to conduct security assessments efficiently. This approach aims to revolutionize penetration testing by merging high functionality with unparalleled portability.
基金support of this project through the Southwest Regional Partnership on Carbon Sequestration(Grant No.DE-FC26-05NT42591)Improving Production in the Emerging Paradox Oil Play(Grant No.DE-FE0031775).
文摘Geomechanical properties of rocks vary across different measurement scales,primarily due to heterogeneity.Micro-scale geomechanical tests,including micro-scale“scratch tests”and nano-scale nanoindentation tests,are attractive at different scales.Each method requires minimal sample volume,is low cost,and includes a relatively rapid measurement turnaround time.However,recent micro-scale test results–including scratch test results and nanoindentation results–exhibit tangible variance and uncertainty,suggesting a need to correlate mineral composition mapping to elastic modulus mapping to isolate the relative impact of specific minerals.Different research labs often utilize different interpretation methods,and it is clear that future micro-mechanical tests may benefit from standardized testing and interpretation procedures.The objectives of this study are to seek options for standardized testing and interpretation procedures,through two specific objectives:(1)Quantify chemical and physical controls on micro-mechanical properties and(2)Quantify the source of uncertainties associated with nanoindentation measurements.To reach these goals,we conducted mechanical tests on three different scales:triaxial compression tests,scratch tests,and nanoindentation tests.We found that mineral phase weight percentage is highly correlated with nanoindentation elastic modulus distribution.Finally,we conclude that nanoindentation testing is a mineralogy and microstructure-based method and generally yields significant uncertainty and overestimation.The uncertainty of the testing method is largely associated with not mapping pore space a priori.Lastly,the uncertainty can be reduced by combining phase mapping and modulus mapping with substantial and random data sampling.
基金supported by the Natural Science Foundation of Chongqing(Grant No.csts2018jcyjAX0016)Funded by the Senior Medical Talents Program of Chongqing for Young and Middle-aged.
文摘The possible application of magnesium(Mg)in glaucoma surgical treatment has been investigated in our previous work.In this paper,the degradation behavior and biocompatibility of Mg coated with hydroxyapatite(HA)and dicalcium phosphate dihydrate(DCPD)in eye environment were evaluated,and uncoated Mg was used for comparison.It was found that uniform corrosion occurred macroscopically to the coated Mg samples in sodium lactate ringer’s injection(SLRI)as well as in the rabbit eyes.In micro-scale,the corrosion was characterized by local cracking and pitting primarily.Mg and calcium(Ca)were incorporated into the surface corrosion products and a multi-layer structure was formed.Compared to other samples,HA-coated Mg slowed down dramatically the alkalinity of the solution and the ion release of the sample,and exhibited the lowest corrosion rate in SLRI,which was about 0.22 mm/a.In terms of biocompatibility,fibroblasts demonstrated high viability in the HA-coated and DCPD-coated Mg groups(p<0.05)in vitro.In vivo,HA-coated Mg was found to show lower inflammatory response and fibrosis than the other groups did,as indicated by hematoxylin-eosin and immunofluorescence staining.During the degrading process of HA-coated Mg in the rabbits’eyes,no inflammation was found in the anterior chamber,lens,and vitreous body.HA-coated Mg was fully biodegraded fifteen weeks post-operation,and the scleral drainage channel(SDC)was formed without obvious scarring.It is concluded that HA-coated Mg implantation is a promising adjunctive procedure to improve the success rate of trabeculectomy.Statement of significance:Magnesium(Mg)has shown to be a potential biomaterial for ophthalmic implants in our previous work.However,inflammatory response resulted from the low corrosion resistance of Mg is a major concern.It is shown here that Mg coated with different calcium phosphates can improve these properties in varying degrees and keep the scleral drainage channel unobstructed and unscarred.Based on our in vitro and in vivo studies,HA-coated Mg exhibited a better degradation behavior and excellent biocompatibility.The scleral drainage channel still exists and aqueous humor flows out smoothly after the full degradation of the implant.It is concluded that HA-coated Mg is a promising biomaterial to increase the therapeutic efficiency of trabeculectomy for glaucoma.
基金supported by the National Natural Science Foundation of China(Nos.52371070 and 52271249),the Key Research and Development Program of Shaanxi,China(No.2023-YBGY-488)the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University(No.SKLSP202415)Additional support was provided by the Xi’an Talent Plan,China(No.XAYC240016)。
文摘Although the degradability and biosafety of magnesium alloys make them advantageous for biological applications,medical implants made of magnesium alloys often fail prematurely due to corrosion.Therefore,improving the corrosion resistance of magnesium alloys has become an urgent problem in the alloy design process.In this study,we designed and prepared Mg-xZn-0.5Y-0.5Zr(x=1,2,and 3,wt%)alloys in a hot extruded state and analyzed their surface structure through scanning electron microscopy,energy dispersion spectrometry,and X-ray diffraction.It was found that increasing the Zn content refined the recrystallized grains in the alloy.Particularly in Mg-3Zn-0.5Y-0.5Zr,the I phase became finer,forming both granular and nanoscale needle-like particles.Surface characterization after the immersion experiment showed that the corrosion product layer was mainly composed of Mg(OH)_(2),Zn(OH)_(2),CaCO_(3),and hy-droxyapatite.The degradation rate of ZW305K was the lowest,measured as 4.1 and 6.0 mm·a^(-1) with the hydrogen precipitation method and weight loss method respectively.Electrochemical experiments further explained the corrosion circuit model of the alloy in solution and confirmed the earlier results.The maximum polarization resistance of ZW305K was 874.5Ω·cm^(2),and the lowest corrosion current density was 0.104 mA·cm^(-2).As a biomedical alloy,it must exhibit good biocompatibility,so the alloy was also tested through cytotoxicity,cell adhesion,and staining experiments.The cell viability of each group after 48 h was greater than 80%,showing that the addition of zinc enhances the alloy’s biocompatibility.In summary,the prepared alloys have the potential to be used as biodegradable implant materials.
文摘The China Spallation Neutron Source(CSNS)is the fourth pulsed accelerator-driven neutron source in the world,and it achieved its design target of 100 kW in 2020.The planned China Spallation Neutron Source Phase II(CSNS-II)commenced in 2024.The CSNS-II linac design primarily involves the addition of a radio-frequency ion source and a section of a superconducting linear accelerator composed of two types of superconducting cavities,namely double-spoke and six-cell elliptical cavities,after the drift tube linac(DTL).The development of the double-spoke superconducting cavity began in early 2021,and by January 2023,the welding,post-processing,and vertical tests of two 324 MHz double-spoke cavity prototypes were completed,with vertical test gradients of 11.6 and 15 MV/m,and Q_(0)≥3×10^(10)@E_(acc)≤10 MV/m.The R&D of the cryomodule began in January 2022.In October 2023,the clean assembly of the double-spoke cavity string and cold mass installation of the cryomodule commenced,with the installation of the cryomodule and valve box completing in two months.In January 2024,a horizontal test of the cryomodule was completed,making it the first double-spoke cavity cryomodule in China.The test results showed that the maximum gradients of the two superconducting cavities at a pulse width of 4 ms and repetition frequency of 25 Hz were 12.8 and 15.2 MV/m,respectively.This article provides a detailed introduction to the double-spoke superconducting cavity,tuner,coupler,and cryomodule,elaborates on the clean assembly of the cavity string and cold mass installation of the cryomodule,and provides a detailed analysis of the horizontal test results.
基金the China Scholarship Council for the award of fellowship and funding (nos. 202106890013 and 202206095009)German Academic Exchange Service (DAAD) for the award of fellowship and funding (no. 91870848).
文摘Previous work indicated that long-period stacking ordered(LPSO) phase and/or γ’ in rare earth containing Mg biomaterials had contradictory mechanisms responsible for their degradation in less complex or standard salt media, such as 0.9 % NaCl solution. They needed to be further investigated in a more realistic simulated body fluid(SBF). The present work investigated the influence of the amount and types of intermetallics on the degradation behavior of as-cast Mg-xDy-Zn(x = 5, 10, 15 wt.%) alloys using immersion test in Dulbecco's modified Eagle's medium(DMEM) + Glutamax together with 10 % Fetal bovine serum(FBS) under cell culture conditions. It was revealed that the existence of intermetallics exhibited different effects on the degradation behavior of alloys. At the early stage of immersion, Mg-10Dy-1.5Zn alloy suffered the most serious degradation among these three alloys, owing to its more severe micro galvanic corrosion. With the immersion proceeding, the degradation rate of Mg-5Dy-1.5Zn alloy consistently increased because of the scattered distribution of few intermetallics. In contrast, the continuous network structure of intermetallics and a compact degradation layer provided protection from further degradation for Mg-10Dy-1.5Zn and Mg-15Dy-1.5Zn alloys. In the as-cast Mg-5Dy-1.5Zn alloy, only small amount of intermetallics composed of W, γ’ and18R LPSO phases acted as galvanic cathodes, accelerating its degradation. With Dy content increasing to 10 and 15 wt.%, large amounts of intermetallics including 18R LPSO and dense γ’ phases were formed, which on the other hand can serve as a continuous network barrier to retard degradation propagation. Finally, the good adhesion and proliferation of the Human umbilical cord perivascular(HUCPV) on the surface of the Mg-10Dy-1.5Zn and Mg-15Dy-1.5Zn alloy indicated their good biocompatibility.
文摘Knowledge of the dynamic modulus of bituminous mixtures is practical and theoretically meaningful in pavement design,construction,and monitoring.The tests in the laboratory for the determination of asphalt concrete(AC)moduli include the resilient modulus through the indirect tensile test(EN 12697-26),the complex modulus through the four point bending beam(EN 12697-26),the asphalt mixture performance tester(AMPT)and the simple performance tester(SPT)(AASHTO T342).Unfortunately,the tests above are time-consuming and quite expensive.On the other hand,the standard ASTM E1876 for resonant tests applies only to very thin(stocky)cylindrical samples(with a thickness-to-radius ratio,t/r,lower than 0.5)while the typical AC samples produced in the laboratory do not satisfy the ASTM E1876 requirements.Consequently,the main objective of this study is to set up and implement a tentative method to extend the range of applicability of the standard ASTM E1876 to common AC samples.The methodology was to carry out resonant tests on slender samples and to cut each of them into stocky samples(these latter complying with ASTM E1876 requirements in terms of t/r),deriving the master curve per material.These master curves allowed for deriving the value of the dynamic modulus for the given selected sample under its particular test conditions during the resonant test(i.e.,temperature and frequency).Consequently,simplified formulae were provided for AC samples.Results were compared to Witczak's estimates.These formulae provide an approximate tool to carry out low-cost and high-speed inferences at the laboratory stage on common AC samples,whatever their thickness is.Additional studies are needed to investigate the reliability of the method further and reduce uncertainties.
文摘In recent years,the application scenarios of electrical and electronic products have become increasingly diverse worldwide.The impact of climatic environmental tests on the performance of related products has attracted much attention,and formulating scientific and reasonable environmental test plans has become an important step to ensure product quality and reliability.
基金the Natural Science Foundation of China(Nos.52205218,52401297)Natural Science Foundation of Shan-dong Province,China(Nos.ZR2020QE024 andZR2021QB015)the Youth Innovation Team Project of Higher Education Institutions in Shandong Province(No.2022KJ272).
文摘Utilizing nanotechnology and composites to create a protective film on titanium alloy is an effective means of achieving the desired high performance.Self-assembly of nanocomposite structures offers a promising route to forming high entropy alloy films(HEAFs),but controlled preparation remains challeng-ing.This work used magnetron sputtering through adjusting preparation parameters to prepare ZrNbTi-CrCu HEAFs,achieving a significant improvement in corrosion resistance and biocompatibility induced by the precipitation of Cu.According to the electrochemical corrosion test,without obvious corrosion pits on the surface of S2 after corrosion,a passivation film composed of bimetallic oxide CuCrO2 formed on the film surface,indicating that ZrNbTiCrCu HEAFs have remarkable corrosion resistance performance.In the cytocompatibility experiment,the cell viability of HEAFs reached over 95%due to the precipitation of Cu,suggesting their excellent biocompatibility.In addition,ZrNbTiCrCu HEAFs exhibit outstanding an-tibacterial ability,especially when the sputtering current is 0.6 A,and the in vitro antibacterial rate of the sample against Escherichia coli is close to 99%.
