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
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
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
In high-risk industrial environments like nuclear power plants,precise defect identification and localization are essential for maintaining production stability and safety.However,the complexity of such a harsh enviro...In high-risk industrial environments like nuclear power plants,precise defect identification and localization are essential for maintaining production stability and safety.However,the complexity of such a harsh environment leads to significant variations in the shape and size of the defects.To address this challenge,we propose the multivariate time series segmentation network(MSSN),which adopts a multiscale convolutional network with multi-stage and depth-separable convolutions for efficient feature extraction through variable-length templates.To tackle the classification difficulty caused by structural signal variance,MSSN employs logarithmic normalization to adjust instance distributions.Furthermore,it integrates classification with smoothing loss functions to accurately identify defect segments amid similar structural and defect signal subsequences.Our algorithm evaluated on both the Mackey-Glass dataset and industrial dataset achieves over 95%localization and demonstrates the capture capability on the synthetic dataset.In a nuclear plant's heat transfer tube dataset,it captures 90%of defect instances with75%middle localization F1 score.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
This article introduces the composition and working principle of home appliance control board automation testing equipment,elaborates on the importance of key technical indicators,explains the integrated design of fun...This article introduces the composition and working principle of home appliance control board automation testing equipment,elaborates on the importance of key technical indicators,explains the integrated design of functional modules,signal processing modules,and data analysis modules,and covers aspects such as the application of machine learning algorithms and the establishment of fault waveform databases.Finally,it looks forward to the development of intelligent testing systems and emphasizes the importance of building a standardized testing system.展开更多
With the rapid development and commercialization of wireless communications,the execution of OTA testing requires a tremendous amount of test time.Therefore,test time reduction is of great significance.The objective o...With the rapid development and commercialization of wireless communications,the execution of OTA testing requires a tremendous amount of test time.Therefore,test time reduction is of great significance.The objective of this article is to determine optimal measurement grids for SISO OTA testing of 5G Sub-6 GHz user equipments(UEs)in anechoic chamber with satisfactory accuracy and efficiency.The effect of different grid configurations on OTA performance is analyzed quantitatively using reference radiation patterns at different bands.These patterns are utilized to mimic the worst-case radiation patterns of 5G Sub-6 GHz UEs.Subsequently,the associated measurement uncertainty(MU)terms are quantitatively analyzed and determined based on statistical analysis.According to the comparison of calculated MUs,reduction of grid points from currentlyrequired 62(30/30,Δθ/Δϕ)to 26(45/45)could achieve roughly 60%test time reduction for Sub-6 GHz,while still maintaining an uncertainty level of≤0.25 dB.These values can be further reduced to 14(60/60)with 80%reduction for Sub-3 GHz.More importantly,the recommended grid configurations in this research are applicable to both TIS and TRP testing.展开更多
Ti-Mo-O alloys were used to analyze the effect of Mo and O contents on the mechanical compatibility and biocompatibility.The bending modulus,bending yield strength and springback ratio of the alloys were evaluated by ...Ti-Mo-O alloys were used to analyze the effect of Mo and O contents on the mechanical compatibility and biocompatibility.The bending modulus,bending yield strength and springback ratio of the alloys were evaluated by using three-point bending tests and bending load-unloading tests.The biocompatibility was investigated by the adhesion,proliferation and the alkaline phosphatase(ALP)activity of mouse osteoblast-like cells(MC3T3-E1).The results showed that the bending modulus and bending yield strength first were increased and then decreased with the increase in Mo content,while the springback ratio exhibited an opposite trend to the bending modulus.With the increase in O content,the bending modulus remained almost constant,while the bending yield strength was increased.The springback ratio exhibited a similar trend to the bending yield strength.The in vitro biological experiments showed that the Ti-Mo-O alloys had excellent biocompatibility due to the formed stable oxide films on their surface.With the increase in O and Mo contents,the TiO_(2)-MoO_(2)oxide film became denser.Combining with mechanical compatibility and biocompatibility,the Ti-15Mo-0.2O and Ti-15Mo-0.3O alloys were more suitable for the biomedical application of spinal fixation device.展开更多
The integration of Global Navigation Satellite System(GNSS)technology into railway train control systems is a crucial step toward achieving the vision of a digital railway.Traditional train control systems undergo ext...The integration of Global Navigation Satellite System(GNSS)technology into railway train control systems is a crucial step toward achieving the vision of a digital railway.Traditional train control systems undergo extensive in-house tests and prolonged field tests for certification and approval before operational deployment,leading to high costs,delays,and operational disruptions.This paper introduces a GNSS-based train control localization framework which eliminates the need for on-site testing by leveraging train movement dynamics and 3D environment modeling to create a zero on-site testing platform.The proposed framework simulates train movement and the surrounding 3D environment using collected railway line location data and environmental attributes to generate realistic multipath signals and obscuration effects.This approach enables comprehensive laboratory-based case studies for train localization,reducing the huge amount test of needed for physical field trials.The framework is established in house,using the data collected at the Test Base of China Academy of Railway Sciences(Circular Railway).Results from the open area and cutting environment tests demonstrate high localization accuracy repeatability within the simulated environment,validating the feasibility and effectiveness of zero on-site testing for GNSS-based train control systems.This research highlights the potential of GNSS simulation platforms in enhancing cost efficiency,operational safety,and accuracy for future digital railways.展开更多
In the current social environment,the importance of energy conservation and emission reduction is increasing day by day for both the country and its people.Electronic and electrical products,as important items for peo...In the current social environment,the importance of energy conservation and emission reduction is increasing day by day for both the country and its people.Electronic and electrical products,as important items for people’s production and life,require high attention from industry insiders in terms of their energy efficiency testing.Relying on energy efficiency testing can achieve the goal of energy conservation and emission reduction,and related quality control technologies will also inject new momentum into the green development of the industry.This article will discuss the practical strategies of quality control technology for energy efficiency testing of electronic and electrical products based on the significance of such testing,hoping to provide some help.展开更多
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.
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.
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supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(2024ZD0608100)the National Natural Science Foundation of China(62332017,U22A2022)
文摘In high-risk industrial environments like nuclear power plants,precise defect identification and localization are essential for maintaining production stability and safety.However,the complexity of such a harsh environment leads to significant variations in the shape and size of the defects.To address this challenge,we propose the multivariate time series segmentation network(MSSN),which adopts a multiscale convolutional network with multi-stage and depth-separable convolutions for efficient feature extraction through variable-length templates.To tackle the classification difficulty caused by structural signal variance,MSSN employs logarithmic normalization to adjust instance distributions.Furthermore,it integrates classification with smoothing loss functions to accurately identify defect segments amid similar structural and defect signal subsequences.Our algorithm evaluated on both the Mackey-Glass dataset and industrial dataset achieves over 95%localization and demonstrates the capture capability on the synthetic dataset.In a nuclear plant's heat transfer tube dataset,it captures 90%of defect instances with75%middle localization F1 score.
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%.
文摘This article introduces the composition and working principle of home appliance control board automation testing equipment,elaborates on the importance of key technical indicators,explains the integrated design of functional modules,signal processing modules,and data analysis modules,and covers aspects such as the application of machine learning algorithms and the establishment of fault waveform databases.Finally,it looks forward to the development of intelligent testing systems and emphasizes the importance of building a standardized testing system.
基金supported by the Beijing Natural Science Foundation under Grant L253002.
文摘With the rapid development and commercialization of wireless communications,the execution of OTA testing requires a tremendous amount of test time.Therefore,test time reduction is of great significance.The objective of this article is to determine optimal measurement grids for SISO OTA testing of 5G Sub-6 GHz user equipments(UEs)in anechoic chamber with satisfactory accuracy and efficiency.The effect of different grid configurations on OTA performance is analyzed quantitatively using reference radiation patterns at different bands.These patterns are utilized to mimic the worst-case radiation patterns of 5G Sub-6 GHz UEs.Subsequently,the associated measurement uncertainty(MU)terms are quantitatively analyzed and determined based on statistical analysis.According to the comparison of calculated MUs,reduction of grid points from currentlyrequired 62(30/30,Δθ/Δϕ)to 26(45/45)could achieve roughly 60%test time reduction for Sub-6 GHz,while still maintaining an uncertainty level of≤0.25 dB.These values can be further reduced to 14(60/60)with 80%reduction for Sub-3 GHz.More importantly,the recommended grid configurations in this research are applicable to both TIS and TRP testing.
基金supported by the National Natural Science Foundation of China(Grant No.52071051)the(Key)Foundation of Xi'an Key Laboratory of High-Performance Titanium Alloy(No.NIN-HTL-2022-ZD01).
文摘Ti-Mo-O alloys were used to analyze the effect of Mo and O contents on the mechanical compatibility and biocompatibility.The bending modulus,bending yield strength and springback ratio of the alloys were evaluated by using three-point bending tests and bending load-unloading tests.The biocompatibility was investigated by the adhesion,proliferation and the alkaline phosphatase(ALP)activity of mouse osteoblast-like cells(MC3T3-E1).The results showed that the bending modulus and bending yield strength first were increased and then decreased with the increase in Mo content,while the springback ratio exhibited an opposite trend to the bending modulus.With the increase in O content,the bending modulus remained almost constant,while the bending yield strength was increased.The springback ratio exhibited a similar trend to the bending yield strength.The in vitro biological experiments showed that the Ti-Mo-O alloys had excellent biocompatibility due to the formed stable oxide films on their surface.With the increase in O and Mo contents,the TiO_(2)-MoO_(2)oxide film became denser.Combining with mechanical compatibility and biocompatibility,the Ti-15Mo-0.2O and Ti-15Mo-0.3O alloys were more suitable for the biomedical application of spinal fixation device.
基金supported by the National Natural Science Foundation of China(62027809,U2268206,T2222015,U2468202).
文摘The integration of Global Navigation Satellite System(GNSS)technology into railway train control systems is a crucial step toward achieving the vision of a digital railway.Traditional train control systems undergo extensive in-house tests and prolonged field tests for certification and approval before operational deployment,leading to high costs,delays,and operational disruptions.This paper introduces a GNSS-based train control localization framework which eliminates the need for on-site testing by leveraging train movement dynamics and 3D environment modeling to create a zero on-site testing platform.The proposed framework simulates train movement and the surrounding 3D environment using collected railway line location data and environmental attributes to generate realistic multipath signals and obscuration effects.This approach enables comprehensive laboratory-based case studies for train localization,reducing the huge amount test of needed for physical field trials.The framework is established in house,using the data collected at the Test Base of China Academy of Railway Sciences(Circular Railway).Results from the open area and cutting environment tests demonstrate high localization accuracy repeatability within the simulated environment,validating the feasibility and effectiveness of zero on-site testing for GNSS-based train control systems.This research highlights the potential of GNSS simulation platforms in enhancing cost efficiency,operational safety,and accuracy for future digital railways.
文摘In the current social environment,the importance of energy conservation and emission reduction is increasing day by day for both the country and its people.Electronic and electrical products,as important items for people’s production and life,require high attention from industry insiders in terms of their energy efficiency testing.Relying on energy efficiency testing can achieve the goal of energy conservation and emission reduction,and related quality control technologies will also inject new momentum into the green development of the industry.This article will discuss the practical strategies of quality control technology for energy efficiency testing of electronic and electrical products based on the significance of such testing,hoping to provide some help.
