In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order hom...In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order homogenization(ROH)approach.The ROH method typically involves solving multiple finite element problems under periodic conditions to evaluate elastic strain and eigenstrain influence functions in an‘off-line’stage,which offers substantial cost savings compared to direct computational homogenization methods.Due to the unique structure of the fibrous unit cell,“off-line”stage calculation can be eliminated by influence functions obtained analytically.Introducing the standard solid model to the ROH method enables the creation of a comprehensive analytical homogeneous viscoelastic constitutive model.This method treats fibrous composite materials as homogeneous,anisotropic viscoelastic materials,significantly reducing computational time due to its analytical nature.This approach also enables precise determination of a homogenized anisotropic relaxation modulus and accurate capture of various viscoelastic responses under different loading conditions.Three sets of numerical examples,including unit cell tests,three-point beam bending tests,and torsion tests,are given to demonstrate the predictive performance of the homogenized viscoelastic model.Furthermore,the model is validated against experimental measurements,confirming its accuracy and reliability.展开更多
A quasistatic homogenized projection is made to characterize the effective cohesive zone behavior for rough-surface adhesion. In the context of the homogenized projection, the traction versus separation relation for t...A quasistatic homogenized projection is made to characterize the effective cohesive zone behavior for rough-surface adhesion. In the context of the homogenized projection, the traction versus separation relation for the homogenized cohesive zone （HCZ） of a rough interface can be highly oscillatory due to instabilities during microscopic adhesion and decohesion processes. The instabilities are found to occur not only individually but also collectively among the adhesive micro-asperity contacts, leading to extensive energy dissipation. Based on the behaviors of the HCZ relations, a framework for describing instability-induced energy dissipation in rough-surface adhesion is proposed to elucidate the effect of roughness on apparent interface adhesion. Two non- dimensional parameters, α related to roughness morphology and n related to flaw distribution, are identified to be most crucial for controlling the energy dissipation. For an interface with a shallow roughness and a strong intrinsic adhesive strength, the interface adhesion can be stronger if we make it rougher （reducing α） or lower its flaw density （increasing n）. The HCZ projection method can be potentially extended and employed to bridge the apparent adhesion from intrinsic adhesion properties for engineering surfaces with multi-scale shallow roughness.展开更多
In order to recover unknown space-dependent function G(x)or unknown time-dependent function H(t)in the wave source F(x;t)=G(x)H(t),we develop a technique of homogenized function and differencing equations,which can si...In order to recover unknown space-dependent function G(x)or unknown time-dependent function H(t)in the wave source F(x;t)=G(x)H(t),we develop a technique of homogenized function and differencing equations,which can significantly reduce the difficulty in the inverse wave source recovery problem,only needing to solve a few equations in the problem domain,since the initial condition/boundary conditions and a supplementary final time condition are satisfied automatically.As a consequence,the eigenfunctions are used to expand the trial solutions,and then a small scale linear system is solved to determine the expansion coefficients from the differencing equations.Because the ill-posedness of the inverse wave source problem is greatly reduced,the present method is accurate and stable against a large noise up to 50%,of which the numerical tests confirm the observation.展开更多
This paper presents a 3D homogenized model able to simulate the nonlinear effects generated by the interaction of ultrasonic waves with microcracks.A hexahedral element with one horizontal elliptical crack is construc...This paper presents a 3D homogenized model able to simulate the nonlinear effects generated by the interaction of ultrasonic waves with microcracks.A hexahedral element with one horizontal elliptical crack is constructed as a reference model.The reference model is smeared to be orthotropic but with different moduli in tension and compression to account for stiffness asymmetry due to crack opening and closure.Different from the existing homogenized models that usually simplify the representative volume element as a homogeneous part and require only one constitutive model for the equivalent material of the whole structure,we assign the constitutive relationship of the same reference model to all the finite elements but with random principal material orientations to take randomly oriented microcracks into consideration.In this way,the randomness of distributed microcracks can be considered in the framework of continuum mechanics.In this manner,the experimentally observed nonlinear effects,such as the generation of both even and odd harmonics,can be reproduced.The developed model has been verified for a 3D bar and a 3D plate.Particularly,the influence of crack density on the amplitude of higher harmonics is analyzed.展开更多
The progress of research and production of bauxite based homogenized grogs in China was summarized and the achievements of their application and modification in recent years were epitomized.In combination with the sho...The progress of research and production of bauxite based homogenized grogs in China was summarized and the achievements of their application and modification in recent years were epitomized.In combination with the shortcomings existing in the research,production and application,the suggestions of bauxite based homogenized grogs for future development were put forward.展开更多
The global boundness and existence are presented for the kind of the Rosseland equation with a general growth condition. A linearized map in a closed convex set is defined. The image set is precompact, and thus a fixe...The global boundness and existence are presented for the kind of the Rosseland equation with a general growth condition. A linearized map in a closed convex set is defined. The image set is precompact, and thus a fixed point exists. A multi-scale expansion method is used to obtain the homogenized equation. This equation satisfies a similar growth condition.展开更多
Surface relative humidity(RH)is a key element for weather and climate monitoring and research.However,RH is not as commonly applied in studying climate change,partly because the observation series of RH are prone to i...Surface relative humidity(RH)is a key element for weather and climate monitoring and research.However,RH is not as commonly applied in studying climate change,partly because the observation series of RH are prone to inhomogeneous biases due to non-climate changes in the observation system.A homogenized dataset of daily RH series from 746 stations in Chinese mainland for the period 1960–2017,ChinaRHv1.0,has been developed.Most(685 or 91.82%of the total)station time series were inhomogeneous with one or more break points.The major breakpoints occurred in the early 2000s for many stations,especially in the humid and semi-humid zones,due to the implementation of automated observation across the country.The inhomogeneous biases in the early manual records before this change are positive relative to the recent automatic records,for most of the biased station series.There are more break points detected by using the MASH(Multiple Analysis of Series for Homogenization)method,with biases mainly around?0.5%and 0.5%.These inhomogeneous biases are adjusted with reference to the most recent observations for each station.Based on the adjusted observations,the regional mean RH series of China shows little long-term trend during 1960–2017[0.006%(10 yr)^?1],contrasting with a false decreasing trend[?0.414%(10 yr)?1]in the raw data.It is notable that ERA5 reanalysis data match closely with the interannual variations of the raw RH series in China,including the jump in the early 2000s,raising a caveat for its application in studying climate change in the region.展开更多
Daily observations of wind speed at 12 stations in the Greater Beijing Area during 1960–2008 were homogenized using the Multiple Analysis of Series for Homogenization method. The linear trends in the regional mean an...Daily observations of wind speed at 12 stations in the Greater Beijing Area during 1960–2008 were homogenized using the Multiple Analysis of Series for Homogenization method. The linear trends in the regional mean annual and seasonal （winter, spring, summer and autumn） wind speed series were-0.26,-0.39,-0.30,-0.12 and-0.22 m s-1 （10 yr）-1 , respectively. Winter showed the greatest magnitude in declining wind speed, followed by spring, autumn and summer. The annual and seasonal frequencies of wind speed extremes （days） also decreased, more prominently for winter than for the other seasons. The declining trends in wind speed and extremes were formed mainly by some rapid declines during the 1970s and 1980s. The maximum declining trend in wind speed occurred at Chaoyang （CY）, a station within the central business district （CBD） of Beijing with the highest level of urbanization. The declining trends were in general smaller in magnitude away from the city center, except for the winter case in which the maximum declining trend shifted northeastward to rural Miyun （MY）. The influence of urbanization on the annual wind speed was estimated to be about-0.05 m s-1 （10 yr）-1 during 1960–2008, accounting for around one fifth of the regional mean declining trend. The annual and seasonal geostrophic wind speeds around Beijing, based on daily mean sea level pressure （MSLP） from the ERA-40 reanalysis dataset, also exhibited decreasing trends, coincident with the results from site observations. A comparative analysis of the MSLP fields between 1966–1975 and 1992–2001 suggested that the influences of both the winter and summer monsoons on Beijing were weaker in the more recent of the two decades. It is suggested that the bulk of wind in Beijing is influenced considerably by urbanization, while changes in strong winds or wind speed extremes are prone to large-scale climate change in the region.展开更多
Inhomogeneities in the daily mean/maximum/ minimum temperature （Tm/Tmax/Tmin） series from 1960- 2008 at 549 National Standard Stations （NSSs） in China were analyzed by using the Multiple Analysis of Series for Hom...Inhomogeneities in the daily mean/maximum/ minimum temperature （Tm/Tmax/Tmin） series from 1960- 2008 at 549 National Standard Stations （NSSs） in China were analyzed by using the Multiple Analysis of Series for Homogenization （MASH） software package. Typical biases in the dataset were illustrated via the cases of Beijing （B J）, Wutaishan （WT）, Urumqi （UR） and Henan （HN） stations. The homogenized dataset shows a mean warming trend of 0.261/0.193/0.344℃/decade for the annual series of Tm/Tmax/Tmin, slightly smaller than that of the original dataset by 0.006/0.009/0.007℃/decade. However, considerable differences between the adjusted and original datasets were found at the local scale. The adjusted Tmin series shows a significant warming trend almost everywhere for all seasons, while there are a number of stations with an insignificant trend in the original dataset. The adjusted Tm data exhibit significant warming trends annually as well as for the autumn and winter seasons in northern China, and cooling trends only for the summer in the middle reaches of the Yangtze River and parts of central China and for the spring in southwestern China, while the original data show cooling trends at several stations for the annual and seasonal scales in the Qinghai, Shanxi, Hebei, and Xinjiang provinces. The adjusted Tmax data exhibit cooling trends for summers at a number of stations in the mid-lower reaches of the Yangtze and Yellow Rivers and for springs and winters at a few stations in southwestern China, while the original data show cooling trends at three/four stations for the annual/autumn periods in the Qinghai and Yunnan provinces. In general, the number of stations with a cooling trend was much smaller in the adjusted Tm and Tmax dataset than in the original dataset. The cooling trend for summers is mainly due to cooling in August. The results of homogenization using MASH appear to be robust; in particular, different groups of stations with consideration of elevation led to minor effects in the results.展开更多
Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based ...Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based on analysis of empirical cumulative density function（ECDF） regarding climate extremes.The cumulative density functions of daily precipitation series,the trends of annual and seasonal precipitation,and summer extreme events during 1960–2012 in the original and final adjusted series at Beijing station were comparatively analyzed to show the necessity and efficiency of the new method.Results indicate that the ECDF adjustments can improve the homogeneity of high-order moments of daily series and the estimation of climate trends in extremes.The linear trends of the regional-mean annual and seasonal（spring,summer,autumn,and winter）precipitation series are-10.16,4.97,-20.04,5.02,and-0.11 mm（10 yr）-1,respectively.The trends over the BMR increase consistently for spring/autumn and decrease for the whole year/summer; however,the trends for winter decrease in southern parts and increase in northern parts.Urbanization affects local trends of precipitation amount,frequency,and intensity and their geographical patterns.For the urban-influenced sites,urbanization tends to slow down the magnitude of decrease in the precipitation and extreme amount series by approximately-10.4% and-6.0%,respectively; enhance the magnitude of decrease in precipitation frequency series by approximately 5.7%; reduce that of extremes by approximately-8.9%; and promote the decreasing trends in the summer intensity series of both precipitation and extremes by approximately 6.8% and51.5%,respectively.展开更多
Based on the collection and processing of the China national-wide monthly station observational precipitation data in 1900-2009, the data series for each station has been tested for their homogeneity with the Standard...Based on the collection and processing of the China national-wide monthly station observational precipitation data in 1900-2009, the data series for each station has been tested for their homogeneity with the Standard Normalized Homogeneity Test （SNHT） method and the inhomogeneous parts of the series are adjusted or corrected. Based on the data, the precipitation anomalies during 1900-2009 and the climatology normals during 1971-2000 have been transformed into the grid boxes at 5°×5° and 2°×2° resolutions respectively. And two grid form datasets are constructed by combining the normal and anomalies. After that, the missing values for the 5°×5° grid dataset are interpolated by Empirical Orthogonal Function （EOF） techniques. With the datasets of different resolutions, the precipitation change series during 1900-2009 over China's Mainland are built, and the annual and seasonal precipitation trends for the recent 110 years are analyzed. The result indicates that the annual precipitation shows a slight dryer trend during the past 110 years, notwithstanding lack of statistical confidence. It is worth noting that after the interpolation of the missing values, the annual precipitation amounts in the early 1900s become less, which increases the changing trend of the annual precipitation in China for the whole 110 years slightly （from -7.48 mm/100a to -6.48 mm/100a）.展开更多
The microstructure and corrosion behavior of the as-homogenized and as-extruded Mg-xLi-3Al-2Zn-0.5Y alloys(x=4,8,12,wt.%)were studied.The results show that as the Li content increases from 4%to 12%,the matrix transfer...The microstructure and corrosion behavior of the as-homogenized and as-extruded Mg-xLi-3Al-2Zn-0.5Y alloys(x=4,8,12,wt.%)were studied.The results show that as the Li content increases from 4%to 12%,the matrix transfers from singleα-Mg phase,(α-Mg+β-Li)dual phase to singleβ-Li phase.A mixed corrosion feature of intergranular corrosion and pitting corrosion occurs in the Mg-4Li-3Al-2Zn-0.5Y and Mg-12Li-3Al-2Zn-0.5Y alloys.The former is related to the precipitated AlLi phase along the grain boundaries,and the latter is related to the high potential difference between the second phase and the matrix.The corrosion resistance of the as-extruded alloys is better than that of the as-homogenized alloys.The superior corrosion resistance of the as-extruded Mg-8Li-3Al-2Zn-0.5Y alloy with the lowest corrosion rate(P_(W)=(0.63±0.26)mm/a)is attributed to the more uniform distribution of second phases,the protectiveα-Mg phase via sacrificing theβ-Li phase and the relatively integrated oxide film.展开更多
The microstructure of the as-cast 2D70 aluminum alloy and its evolution during homogenization were investigated by means of optical microscopy （OM）, scanning electron microscopy （SEM）, energy dispersive spectrosco...The microstructure of the as-cast 2D70 aluminum alloy and its evolution during homogenization were investigated by means of optical microscopy （OM）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, X-ray diffraction （XRD）, and differential scanning calorimetry （DSC） analysis. The results indicate that the microstructure of the as-cast 2D70 aluminum alloy mainly consists of the dendritic network of aluminum solid solution and intermetallic compounds （Al2CuMg, Al2Cu, Al9FeNi, Cu2FeAl7, and Al7Cu4Ni）. After conventional homogenization, Al/Al2CuMg eutectic phases are dissolved into the matrix, and a small amount of high melting-point eutectic Al/Al2Cu phases exist in the matrix, resulting in an increase in the starting melting temperature. Under double homogenization, the high melting point Al/Al2Cu phases are dissolved, and no obvious change is observed for the size and morphology of Al9FeNi, Cu2FeAl7, and Al7CuaNi compounds.展开更多
Most methods of homogenization of climate data are applied to time series of a single variable, such as daily maximum temperature(Tmax) or daily minimum temperature(Tmin). Consequently, the physical relationship among...Most methods of homogenization of climate data are applied to time series of a single variable, such as daily maximum temperature(Tmax) or daily minimum temperature(Tmin). Consequently, the physical relationship among different variables, e.g., Tmax>Tmin, may be distorted after homogenization of climate series of individual variables. The authors develop a solution to improve consistency among diurnal temperature records, while using the Multiple Analysis of Series for Homogenization(MASH) method to homogenize the observation series of daily mean temperature(Tm), Tmin, and Tmax at 545 stations in China for the period 1960–2011, called CHTM2.0. In the previous version of this homogenized dataset based on MASH(CHTM1.0) for the period 1960–2008, there are a few records(0.039% of the total) that are physically inconsistent. For developing CHTM2.0, the authors apply additional adjustments for each day with inconsistent temperature records, in order to hold Tmax>Tm>Tmin. Although the additional adjustments are barely influential for estimating long-term climate trends in China as a whole(because very few records are additionally adjusted), the newly introduced solution improves the physical consistency throughout the dataset. It is also helpful for developing more reasonable homogenized climate datasets with regard to physical consistency among multiple variables. Based on CHTM2.0, the annual Tmax/Tm/Tmin series averaged over China for the period 1960–2011 show significant warming trends of about 0.19/0.25/0.34°C per decade, respectively. Large warming trends of up to 0.425/0.596/ 0.704°C per decade occur in northeastern and northwestern China.展开更多
The present study investigates the mechanical and in-vitro corrosion behavior of Mg-4Zn-0.5Ca-0.8Mn alloy in optimum homogenized conditions.The optimization of the homogenization parameters has been carried out employ...The present study investigates the mechanical and in-vitro corrosion behavior of Mg-4Zn-0.5Ca-0.8Mn alloy in optimum homogenized conditions.The optimization of the homogenization parameters has been carried out employing thermodynamic calculations and kinetic modeling.The model utilizes the inter-diffusivity of the solute elements and predicts that∼6–24 h of homogenization at 633 K effectively redistributes the elements in the Mg matrix.Based on the insights obtained from the simulations,the as-cast Mg-4Zn-0.5Ca-0.8Mn alloy was subjected to homogenization heat treatment process for 6–24h.The microstructural study through optical microscopy and scanning electron microscopy(SEM)revealed that the interconnected network of second phase precipitates substantially dissolve within 24 h,implying adequate homogenization.Moreover,fine Mg-Zn based precipitates with varied morphology and phase fractions also evolved during homogenization treatment,as confirmed through SEM and transmission electron microscopy.In the 12 h homogenized specimen,the highest fraction of uniformly dispersed fine precipitates resulted in the highest strength(∼225 MPa).On the other hand,a substantial disruption in coarse precipitate network and lower aspect ratio of fine Mg-Zn precipitates led to the highest ductility(∼8%)in this specimen.In the 24 h homogenized specimen,the ductility reduced marginally owing to higher aspect ratio of fine precipitates.The immersion and electrochemical tests(viz.,potentiodynamic polarization and electrochemical impedance spectroscopy)carried out in Hank’s solution revealed that the 24 h homogenized specimen exhibits the best corrosion properties.The least fraction of Ca_(2)Mg_(6)Zn_(3)phase with maximum disruption in interconnectivity,in combination with a small fraction of fine equilibrium MgZn_(2)precipitates,resulted in suppression of localized corrosion in this specimen.This promotes the formation of the most stable and compact product layer over the specimen,resulting in the highest corrosion resistance.展开更多
Based on the statistical method and the historical evolution of meteorological sta- tions, the temperature time series for each station in Hunan Province during 1910-2014 are tested for their homogeneity and then corr...Based on the statistical method and the historical evolution of meteorological sta- tions, the temperature time series for each station in Hunan Province during 1910-2014 are tested for their homogeneity and then corrected. The missing data caused by war and other reasons at the 8 meteorological stations which had records before 1950 is filled by interpola- tion using adjacent observations, and complete temperature time series since the estab- lishment of stations are constructed. After that, according to the representative analysis of each station in different time periods, the temperature series of Hunan Province during 1910-2014 are built and their changes are analyzed. The results indicate that the annual mean temperature has a significant warming trend during 1910-2014 and the seasonal mean temperature has the largest rising amplitude in winter and spring, followed by autumn, but no significant change in summer. Temperature variation over Hunan Province has several sig- nificant warm-cold alternations and more frequent than that in whole China. Annual and seasonal mean temperatures except summer and autumn have abrupt warming changes in the recent 100 years. The wavelet analysis suggests that the annual and four seasonal mean temperatures in recent 100 years have experienced two climatic shifts from cold to warm.展开更多
A unique porcine extracellular matrix (ECM) derived injectable tissue construct with 100 nm or 20 nm gold nanoparticles (AuNP) was developed for musculoskeletal tissue engineering applications. ECM has been shown to e...A unique porcine extracellular matrix (ECM) derived injectable tissue construct with 100 nm or 20 nm gold nanoparticles (AuNP) was developed for musculoskeletal tissue engineering applications. ECM has been shown to encourage cellularity and tissue remodeling due to its release of growth factors while AuNP have been shown to reduce reactive oxygen species (ROS) levels. Injectable tissue constructs were created by homogenizing decellularized porcine diaphragm tendon conjugated with 100 nm or 20 nm AuNP at 1x, 4x, and 8x concentrations. Extrusion force testing demonstrated that homogenized tissue constructs were injectable at an appropriate cannula size and force. L-929 murine fibroblasts were used to measure cell viability, cell proliferation, intracellular ROS levels, and cell migration in response to constructs. Enhanced cell viability and proliferation are observed on 1 × 20 nm AuNP constructs. ROS assays demonstrate reduced cellular ROS concentrations from all 20 nm AuNP constructs and from 8 × 100 nm AuNP constructs compared with constructs without nanoparticles. Cellular migration is higher towards 4 × 20 nm AuNP constructs compared with constructs without nanoparticles. Results support the potential use of a porcine ECM derived injectable tissue construct with AuNP as an injectable tissue construct to reduce inflammation and to promote tissue remodeling in musculoskeletal tissue engineering applications.展开更多
Preparation of bauxite-based sintered mullite homogenized grog was introduced and its application in ladle castable was studied.Two kinds of bauxite-based sintered mullite homogenized grogs were used,named as GA and G...Preparation of bauxite-based sintered mullite homogenized grog was introduced and its application in ladle castable was studied.Two kinds of bauxite-based sintered mullite homogenized grogs were used,named as GA and GB,respectively.The results show that bauxitebased sintered homogenized grog with uniform components,stable microstructure and mullite as main crystal phase can be prepared using joint process of three-step homogenization,automatic component batching,wet cogrinding,high-temperature calcinations.It also indicates that carbon steel ladle castables with GA or composite aggregate of GA and GB as main materials have the same excellent general performance indicators,great erosion resistance,anti-strip performance and longer service life in field applications,and compared with castables with single aggregate of GA,the castables with aggregate of GA and GB as main materials had higher cost performance because of lower bulk density of GB.展开更多
Deep-level traps at the buried interface of perovskite and energy mismatch problems between the perovskite layer and heterogeneous interfaces restrict the development of ideal homogenized films and efficient perovskit...Deep-level traps at the buried interface of perovskite and energy mismatch problems between the perovskite layer and heterogeneous interfaces restrict the development of ideal homogenized films and efficient perovskite solar cells(PSCs)using the one-step spin-coating method.Here,we strategically employed sparingly soluble germanium iodide as a homogenized bulk in-situ reconstruction inducing material preferentially aggregated at the perovskite buried interface with gradient doping,markedly reducing deep-level traps and withstanding local lattice strain,while minimizing non-radiative recombination losses and enhancing the charge carrier lifetime over 9μs.Furthermore,this gradient doping assisted in modifying the band diagram at the buried interface into a desirable flattened alignment,substantially mitigating the energy loss of charge carriers within perovskite films and improving the carrier extraction equilibrium.As a result,the optimized device achieved a champion power conversion efficiency of 25.24% with a fill factor of up to 84.65%,and the unencapsulated device also demonstrated excellent light stability and humidity stability.This work provides a straightforward and reliable homogenization strategy of perovskite components for obtaining efficient and stable PSCs.展开更多
As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal...As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.展开更多
基金support by the National Key R&D Program of China(Grant No.2023YFA1008901)the National Natural Science Foundation of China(Grant Nos.11988102,12172009)is gratefully acknowledged.
文摘In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational homogenization.The method is based on the reduced-order homogenization(ROH)approach.The ROH method typically involves solving multiple finite element problems under periodic conditions to evaluate elastic strain and eigenstrain influence functions in an‘off-line’stage,which offers substantial cost savings compared to direct computational homogenization methods.Due to the unique structure of the fibrous unit cell,“off-line”stage calculation can be eliminated by influence functions obtained analytically.Introducing the standard solid model to the ROH method enables the creation of a comprehensive analytical homogeneous viscoelastic constitutive model.This method treats fibrous composite materials as homogeneous,anisotropic viscoelastic materials,significantly reducing computational time due to its analytical nature.This approach also enables precise determination of a homogenized anisotropic relaxation modulus and accurate capture of various viscoelastic responses under different loading conditions.Three sets of numerical examples,including unit cell tests,three-point beam bending tests,and torsion tests,are given to demonstrate the predictive performance of the homogenized viscoelastic model.Furthermore,the model is validated against experimental measurements,confirming its accuracy and reliability.
基金Project supported in part by the Nano and Bio Mechanics Program,under award CMS-0511961in part by the MRSEC Program,under award DMR-0520651,of the National Science Foundation
文摘A quasistatic homogenized projection is made to characterize the effective cohesive zone behavior for rough-surface adhesion. In the context of the homogenized projection, the traction versus separation relation for the homogenized cohesive zone （HCZ） of a rough interface can be highly oscillatory due to instabilities during microscopic adhesion and decohesion processes. The instabilities are found to occur not only individually but also collectively among the adhesive micro-asperity contacts, leading to extensive energy dissipation. Based on the behaviors of the HCZ relations, a framework for describing instability-induced energy dissipation in rough-surface adhesion is proposed to elucidate the effect of roughness on apparent interface adhesion. Two non- dimensional parameters, α related to roughness morphology and n related to flaw distribution, are identified to be most crucial for controlling the energy dissipation. For an interface with a shallow roughness and a strong intrinsic adhesive strength, the interface adhesion can be stronger if we make it rougher （reducing α） or lower its flaw density （increasing n）. The HCZ projection method can be potentially extended and employed to bridge the apparent adhesion from intrinsic adhesion properties for engineering surfaces with multi-scale shallow roughness.
文摘In order to recover unknown space-dependent function G(x)or unknown time-dependent function H(t)in the wave source F(x;t)=G(x)H(t),we develop a technique of homogenized function and differencing equations,which can significantly reduce the difficulty in the inverse wave source recovery problem,only needing to solve a few equations in the problem domain,since the initial condition/boundary conditions and a supplementary final time condition are satisfied automatically.As a consequence,the eigenfunctions are used to expand the trial solutions,and then a small scale linear system is solved to determine the expansion coefficients from the differencing equations.Because the ill-posedness of the inverse wave source problem is greatly reduced,the present method is accurate and stable against a large noise up to 50%,of which the numerical tests confirm the observation.
基金supported by the National Natural Science Foundation of China (51875277,52175141,and 51921003)Natural Science Foundation of Jiangsu Province (BK20200414 and BK20220133)+3 种基金China Postdoctoral Science Foundation (2021TQ0152 and 2022M711616)the Foundation Strengthening Plan Technology Fund (2019-JCJQ-JJ-337)Jiangsu Funding Program for Excellent Postdoctoral Talent (2022ZB159)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘This paper presents a 3D homogenized model able to simulate the nonlinear effects generated by the interaction of ultrasonic waves with microcracks.A hexahedral element with one horizontal elliptical crack is constructed as a reference model.The reference model is smeared to be orthotropic but with different moduli in tension and compression to account for stiffness asymmetry due to crack opening and closure.Different from the existing homogenized models that usually simplify the representative volume element as a homogeneous part and require only one constitutive model for the equivalent material of the whole structure,we assign the constitutive relationship of the same reference model to all the finite elements but with random principal material orientations to take randomly oriented microcracks into consideration.In this way,the randomness of distributed microcracks can be considered in the framework of continuum mechanics.In this manner,the experimentally observed nonlinear effects,such as the generation of both even and odd harmonics,can be reproduced.The developed model has been verified for a 3D bar and a 3D plate.Particularly,the influence of crack density on the amplitude of higher harmonics is analyzed.
文摘The progress of research and production of bauxite based homogenized grogs in China was summarized and the achievements of their application and modification in recent years were epitomized.In combination with the shortcomings existing in the research,production and application,the suggestions of bauxite based homogenized grogs for future development were put forward.
基金Supported by the National Basic Research Program of China(973 Program)(No.2012CB025904)the National Natural Science Foundation of China(No.90916027)
文摘The global boundness and existence are presented for the kind of the Rosseland equation with a general growth condition. A linearized map in a closed convex set is defined. The image set is precompact, and thus a fixed point exists. A multi-scale expansion method is used to obtain the homogenized equation. This equation satisfies a similar growth condition.
基金the Chinese Academy of Sciences(Project Nos.XDA19030402 and XDA20020201)the UK–China Research&Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP)China as part of the Newton Fund(SFBT&NF).
文摘Surface relative humidity(RH)is a key element for weather and climate monitoring and research.However,RH is not as commonly applied in studying climate change,partly because the observation series of RH are prone to inhomogeneous biases due to non-climate changes in the observation system.A homogenized dataset of daily RH series from 746 stations in Chinese mainland for the period 1960–2017,ChinaRHv1.0,has been developed.Most(685 or 91.82%of the total)station time series were inhomogeneous with one or more break points.The major breakpoints occurred in the early 2000s for many stations,especially in the humid and semi-humid zones,due to the implementation of automated observation across the country.The inhomogeneous biases in the early manual records before this change are positive relative to the recent automatic records,for most of the biased station series.There are more break points detected by using the MASH(Multiple Analysis of Series for Homogenization)method,with biases mainly around?0.5%and 0.5%.These inhomogeneous biases are adjusted with reference to the most recent observations for each station.Based on the adjusted observations,the regional mean RH series of China shows little long-term trend during 1960–2017[0.006%(10 yr)^?1],contrasting with a false decreasing trend[?0.414%(10 yr)?1]in the raw data.It is notable that ERA5 reanalysis data match closely with the interannual variations of the raw RH series in China,including the jump in the early 2000s,raising a caveat for its application in studying climate change in the region.
基金supported by grants from the MOST NBRPC(2009CB421401)CNNSF(41075063) and the CMA Institute of Urban Meteorology
文摘Daily observations of wind speed at 12 stations in the Greater Beijing Area during 1960–2008 were homogenized using the Multiple Analysis of Series for Homogenization method. The linear trends in the regional mean annual and seasonal （winter, spring, summer and autumn） wind speed series were-0.26,-0.39,-0.30,-0.12 and-0.22 m s-1 （10 yr）-1 , respectively. Winter showed the greatest magnitude in declining wind speed, followed by spring, autumn and summer. The annual and seasonal frequencies of wind speed extremes （days） also decreased, more prominently for winter than for the other seasons. The declining trends in wind speed and extremes were formed mainly by some rapid declines during the 1970s and 1980s. The maximum declining trend in wind speed occurred at Chaoyang （CY）, a station within the central business district （CBD） of Beijing with the highest level of urbanization. The declining trends were in general smaller in magnitude away from the city center, except for the winter case in which the maximum declining trend shifted northeastward to rural Miyun （MY）. The influence of urbanization on the annual wind speed was estimated to be about-0.05 m s-1 （10 yr）-1 during 1960–2008, accounting for around one fifth of the regional mean declining trend. The annual and seasonal geostrophic wind speeds around Beijing, based on daily mean sea level pressure （MSLP） from the ERA-40 reanalysis dataset, also exhibited decreasing trends, coincident with the results from site observations. A comparative analysis of the MSLP fields between 1966–1975 and 1992–2001 suggested that the influences of both the winter and summer monsoons on Beijing were weaker in the more recent of the two decades. It is suggested that the bulk of wind in Beijing is influenced considerably by urbanization, while changes in strong winds or wind speed extremes are prone to large-scale climate change in the region.
基金supported by the National Basic Research Program of China 2009CB421401 and 2006CB400503
文摘Inhomogeneities in the daily mean/maximum/ minimum temperature （Tm/Tmax/Tmin） series from 1960- 2008 at 549 National Standard Stations （NSSs） in China were analyzed by using the Multiple Analysis of Series for Homogenization （MASH） software package. Typical biases in the dataset were illustrated via the cases of Beijing （B J）, Wutaishan （WT）, Urumqi （UR） and Henan （HN） stations. The homogenized dataset shows a mean warming trend of 0.261/0.193/0.344℃/decade for the annual series of Tm/Tmax/Tmin, slightly smaller than that of the original dataset by 0.006/0.009/0.007℃/decade. However, considerable differences between the adjusted and original datasets were found at the local scale. The adjusted Tmin series shows a significant warming trend almost everywhere for all seasons, while there are a number of stations with an insignificant trend in the original dataset. The adjusted Tm data exhibit significant warming trends annually as well as for the autumn and winter seasons in northern China, and cooling trends only for the summer in the middle reaches of the Yangtze River and parts of central China and for the spring in southwestern China, while the original data show cooling trends at several stations for the annual and seasonal scales in the Qinghai, Shanxi, Hebei, and Xinjiang provinces. The adjusted Tmax data exhibit cooling trends for summers at a number of stations in the mid-lower reaches of the Yangtze and Yellow Rivers and for springs and winters at a few stations in southwestern China, while the original data show cooling trends at three/four stations for the annual/autumn periods in the Qinghai and Yunnan provinces. In general, the number of stations with a cooling trend was much smaller in the adjusted Tm and Tmax dataset than in the original dataset. The cooling trend for summers is mainly due to cooling in August. The results of homogenization using MASH appear to be robust; in particular, different groups of stations with consideration of elevation led to minor effects in the results.
基金supported by the State Programs of Science and Technology Development(Grant No.2012BAC22B04)the National Natural Science Foundation of China(Grant No.41475078)+1 种基金the National Department Public Benefit Research Foundation of China(Grant No.GYHY201206013)the Science and Technology program of the Institute of Urban Meteorology(Grant No.IUMKY201302PP0102)
文摘Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based on analysis of empirical cumulative density function（ECDF） regarding climate extremes.The cumulative density functions of daily precipitation series,the trends of annual and seasonal precipitation,and summer extreme events during 1960–2012 in the original and final adjusted series at Beijing station were comparatively analyzed to show the necessity and efficiency of the new method.Results indicate that the ECDF adjustments can improve the homogeneity of high-order moments of daily series and the estimation of climate trends in extremes.The linear trends of the regional-mean annual and seasonal（spring,summer,autumn,and winter）precipitation series are-10.16,4.97,-20.04,5.02,and-0.11 mm（10 yr）-1,respectively.The trends over the BMR increase consistently for spring/autumn and decrease for the whole year/summer; however,the trends for winter decrease in southern parts and increase in northern parts.Urbanization affects local trends of precipitation amount,frequency,and intensity and their geographical patterns.For the urban-influenced sites,urbanization tends to slow down the magnitude of decrease in the precipitation and extreme amount series by approximately-10.4% and-6.0%,respectively; enhance the magnitude of decrease in precipitation frequency series by approximately 5.7%; reduce that of extremes by approximately-8.9%; and promote the decreasing trends in the summer intensity series of both precipitation and extremes by approximately 6.8% and51.5%,respectively.
基金State Key Development Program of Basic Research of China,No.2010CB951600National Science and Technology Supporting Program of the 11th and 12th Five-Year Plan Periods,No.2007BAC29B01+2 种基金 No.2012BAC22B00China Meteorological Administration Special Foundation for Climate Change, No.CCSF201224No.540000G010C01
文摘Based on the collection and processing of the China national-wide monthly station observational precipitation data in 1900-2009, the data series for each station has been tested for their homogeneity with the Standard Normalized Homogeneity Test （SNHT） method and the inhomogeneous parts of the series are adjusted or corrected. Based on the data, the precipitation anomalies during 1900-2009 and the climatology normals during 1971-2000 have been transformed into the grid boxes at 5°×5° and 2°×2° resolutions respectively. And two grid form datasets are constructed by combining the normal and anomalies. After that, the missing values for the 5°×5° grid dataset are interpolated by Empirical Orthogonal Function （EOF） techniques. With the datasets of different resolutions, the precipitation change series during 1900-2009 over China's Mainland are built, and the annual and seasonal precipitation trends for the recent 110 years are analyzed. The result indicates that the annual precipitation shows a slight dryer trend during the past 110 years, notwithstanding lack of statistical confidence. It is worth noting that after the interpolation of the missing values, the annual precipitation amounts in the early 1900s become less, which increases the changing trend of the annual precipitation in China for the whole 110 years slightly （from -7.48 mm/100a to -6.48 mm/100a）.
基金financially supported by the National Natural Science Foundation of China(Nos.51771115,51775334,51821001,U2037601)Open Fund of State Key Laboratory of Advanced Forming Technology and Equipment(No.SKL2020005)。
文摘The microstructure and corrosion behavior of the as-homogenized and as-extruded Mg-xLi-3Al-2Zn-0.5Y alloys(x=4,8,12,wt.%)were studied.The results show that as the Li content increases from 4%to 12%,the matrix transfers from singleα-Mg phase,(α-Mg+β-Li)dual phase to singleβ-Li phase.A mixed corrosion feature of intergranular corrosion and pitting corrosion occurs in the Mg-4Li-3Al-2Zn-0.5Y and Mg-12Li-3Al-2Zn-0.5Y alloys.The former is related to the precipitated AlLi phase along the grain boundaries,and the latter is related to the high potential difference between the second phase and the matrix.The corrosion resistance of the as-extruded alloys is better than that of the as-homogenized alloys.The superior corrosion resistance of the as-extruded Mg-8Li-3Al-2Zn-0.5Y alloy with the lowest corrosion rate(P_(W)=(0.63±0.26)mm/a)is attributed to the more uniform distribution of second phases,the protectiveα-Mg phase via sacrificing theβ-Li phase and the relatively integrated oxide film.
文摘The microstructure of the as-cast 2D70 aluminum alloy and its evolution during homogenization were investigated by means of optical microscopy （OM）, scanning electron microscopy （SEM）, energy dispersive spectroscopy （EDS）, X-ray diffraction （XRD）, and differential scanning calorimetry （DSC） analysis. The results indicate that the microstructure of the as-cast 2D70 aluminum alloy mainly consists of the dendritic network of aluminum solid solution and intermetallic compounds （Al2CuMg, Al2Cu, Al9FeNi, Cu2FeAl7, and Al7Cu4Ni）. After conventional homogenization, Al/Al2CuMg eutectic phases are dissolved into the matrix, and a small amount of high melting-point eutectic Al/Al2Cu phases exist in the matrix, resulting in an increase in the starting melting temperature. Under double homogenization, the high melting point Al/Al2Cu phases are dissolved, and no obvious change is observed for the size and morphology of Al9FeNi, Cu2FeAl7, and Al7CuaNi compounds.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05090105)the National Department Public Benefit Research Foundation of China (Grant No. GYHY201206013)+2 种基金the State Programs of Science and Technology Development (Grant No. 2012BAC22B04)the Urban Meteorological Science Research Foundation (UMRF201211)WU Hongyi was supported by the Science and Technology Program of Institute of Urban Meteorology (Grant No. IUMKY201302PP0102)
文摘Most methods of homogenization of climate data are applied to time series of a single variable, such as daily maximum temperature(Tmax) or daily minimum temperature(Tmin). Consequently, the physical relationship among different variables, e.g., Tmax>Tmin, may be distorted after homogenization of climate series of individual variables. The authors develop a solution to improve consistency among diurnal temperature records, while using the Multiple Analysis of Series for Homogenization(MASH) method to homogenize the observation series of daily mean temperature(Tm), Tmin, and Tmax at 545 stations in China for the period 1960–2011, called CHTM2.0. In the previous version of this homogenized dataset based on MASH(CHTM1.0) for the period 1960–2008, there are a few records(0.039% of the total) that are physically inconsistent. For developing CHTM2.0, the authors apply additional adjustments for each day with inconsistent temperature records, in order to hold Tmax>Tm>Tmin. Although the additional adjustments are barely influential for estimating long-term climate trends in China as a whole(because very few records are additionally adjusted), the newly introduced solution improves the physical consistency throughout the dataset. It is also helpful for developing more reasonable homogenized climate datasets with regard to physical consistency among multiple variables. Based on CHTM2.0, the annual Tmax/Tm/Tmin series averaged over China for the period 1960–2011 show significant warming trends of about 0.19/0.25/0.34°C per decade, respectively. Large warming trends of up to 0.425/0.596/ 0.704°C per decade occur in northeastern and northwestern China.
文摘The present study investigates the mechanical and in-vitro corrosion behavior of Mg-4Zn-0.5Ca-0.8Mn alloy in optimum homogenized conditions.The optimization of the homogenization parameters has been carried out employing thermodynamic calculations and kinetic modeling.The model utilizes the inter-diffusivity of the solute elements and predicts that∼6–24 h of homogenization at 633 K effectively redistributes the elements in the Mg matrix.Based on the insights obtained from the simulations,the as-cast Mg-4Zn-0.5Ca-0.8Mn alloy was subjected to homogenization heat treatment process for 6–24h.The microstructural study through optical microscopy and scanning electron microscopy(SEM)revealed that the interconnected network of second phase precipitates substantially dissolve within 24 h,implying adequate homogenization.Moreover,fine Mg-Zn based precipitates with varied morphology and phase fractions also evolved during homogenization treatment,as confirmed through SEM and transmission electron microscopy.In the 12 h homogenized specimen,the highest fraction of uniformly dispersed fine precipitates resulted in the highest strength(∼225 MPa).On the other hand,a substantial disruption in coarse precipitate network and lower aspect ratio of fine Mg-Zn precipitates led to the highest ductility(∼8%)in this specimen.In the 24 h homogenized specimen,the ductility reduced marginally owing to higher aspect ratio of fine precipitates.The immersion and electrochemical tests(viz.,potentiodynamic polarization and electrochemical impedance spectroscopy)carried out in Hank’s solution revealed that the 24 h homogenized specimen exhibits the best corrosion properties.The least fraction of Ca_(2)Mg_(6)Zn_(3)phase with maximum disruption in interconnectivity,in combination with a small fraction of fine equilibrium MgZn_(2)precipitates,resulted in suppression of localized corrosion in this specimen.This promotes the formation of the most stable and compact product layer over the specimen,resulting in the highest corrosion resistance.
基金China Meteorological Administration Special Public Welfare Research Fund,GYHY201406016
文摘Based on the statistical method and the historical evolution of meteorological sta- tions, the temperature time series for each station in Hunan Province during 1910-2014 are tested for their homogeneity and then corrected. The missing data caused by war and other reasons at the 8 meteorological stations which had records before 1950 is filled by interpola- tion using adjacent observations, and complete temperature time series since the estab- lishment of stations are constructed. After that, according to the representative analysis of each station in different time periods, the temperature series of Hunan Province during 1910-2014 are built and their changes are analyzed. The results indicate that the annual mean temperature has a significant warming trend during 1910-2014 and the seasonal mean temperature has the largest rising amplitude in winter and spring, followed by autumn, but no significant change in summer. Temperature variation over Hunan Province has several sig- nificant warm-cold alternations and more frequent than that in whole China. Annual and seasonal mean temperatures except summer and autumn have abrupt warming changes in the recent 100 years. The wavelet analysis suggests that the annual and four seasonal mean temperatures in recent 100 years have experienced two climatic shifts from cold to warm.
文摘A unique porcine extracellular matrix (ECM) derived injectable tissue construct with 100 nm or 20 nm gold nanoparticles (AuNP) was developed for musculoskeletal tissue engineering applications. ECM has been shown to encourage cellularity and tissue remodeling due to its release of growth factors while AuNP have been shown to reduce reactive oxygen species (ROS) levels. Injectable tissue constructs were created by homogenizing decellularized porcine diaphragm tendon conjugated with 100 nm or 20 nm AuNP at 1x, 4x, and 8x concentrations. Extrusion force testing demonstrated that homogenized tissue constructs were injectable at an appropriate cannula size and force. L-929 murine fibroblasts were used to measure cell viability, cell proliferation, intracellular ROS levels, and cell migration in response to constructs. Enhanced cell viability and proliferation are observed on 1 × 20 nm AuNP constructs. ROS assays demonstrate reduced cellular ROS concentrations from all 20 nm AuNP constructs and from 8 × 100 nm AuNP constructs compared with constructs without nanoparticles. Cellular migration is higher towards 4 × 20 nm AuNP constructs compared with constructs without nanoparticles. Results support the potential use of a porcine ECM derived injectable tissue construct with AuNP as an injectable tissue construct to reduce inflammation and to promote tissue remodeling in musculoskeletal tissue engineering applications.
文摘Preparation of bauxite-based sintered mullite homogenized grog was introduced and its application in ladle castable was studied.Two kinds of bauxite-based sintered mullite homogenized grogs were used,named as GA and GB,respectively.The results show that bauxitebased sintered homogenized grog with uniform components,stable microstructure and mullite as main crystal phase can be prepared using joint process of three-step homogenization,automatic component batching,wet cogrinding,high-temperature calcinations.It also indicates that carbon steel ladle castables with GA or composite aggregate of GA and GB as main materials have the same excellent general performance indicators,great erosion resistance,anti-strip performance and longer service life in field applications,and compared with castables with single aggregate of GA,the castables with aggregate of GA and GB as main materials had higher cost performance because of lower bulk density of GB.
基金supported by the National Natural Science Foundation of China(62105292)Shaanxi Fundamental Science Research Project for Mathematics and Physics(22JSY015)+3 种基金Young Talent Fund of Xi’an Association for Science and Technology(959202313020)the Natural Science Foundation of Shaanxi Province(2021GXLH-Z-0 and 2020JZ-02)the project of Innovative Team of Shaanxi Province(2020TD-001)the China Fundamental Research Funds for the Central Universities。
文摘Deep-level traps at the buried interface of perovskite and energy mismatch problems between the perovskite layer and heterogeneous interfaces restrict the development of ideal homogenized films and efficient perovskite solar cells(PSCs)using the one-step spin-coating method.Here,we strategically employed sparingly soluble germanium iodide as a homogenized bulk in-situ reconstruction inducing material preferentially aggregated at the perovskite buried interface with gradient doping,markedly reducing deep-level traps and withstanding local lattice strain,while minimizing non-radiative recombination losses and enhancing the charge carrier lifetime over 9μs.Furthermore,this gradient doping assisted in modifying the band diagram at the buried interface into a desirable flattened alignment,substantially mitigating the energy loss of charge carriers within perovskite films and improving the carrier extraction equilibrium.As a result,the optimized device achieved a champion power conversion efficiency of 25.24% with a fill factor of up to 84.65%,and the unencapsulated device also demonstrated excellent light stability and humidity stability.This work provides a straightforward and reliable homogenization strategy of perovskite components for obtaining efficient and stable PSCs.
基金financially supported by the National Key R&D Program of China(No.2022YFE0121300)the National Natural Science Foundation of China(No.52374376)the Introduction Plan for High-end Foreign Experts(No.G2023105001L)。
文摘As a mathematical analysis method,fractal analysis can be used to quantitatively describe irregular shapes with self-similar or self-affine properties.Fractal analysis has been used to characterize the shapes of metal materials at various scales and dimensions.Conventional methods make it difficult to quantitatively describe the relationship between the regular characteristics and properties of metal material surfaces and interfaces.However,fractal analysis can be used to quantitatively describe the shape characteristics of metal materials and to establish the quantitative relationships between the shape characteristics and various properties of metal materials.From the perspective of two-dimensional planes and three-dimensional curved surfaces,this paper reviews the current research status of the fractal analysis of metal precipitate interfaces,metal grain boundary interfaces,metal-deposited film surfaces,metal fracture surfaces,metal machined surfaces,and metal wear surfaces.The relationship between the fractal dimensions and properties of metal material surfaces and interfaces is summarized.Starting from three perspectives of fractal analysis,namely,research scope,image acquisition methods,and calculation methods,this paper identifies the direction of research on fractal analysis of metal material surfaces and interfaces that need to be developed.It is believed that revealing the deep influence mechanism between the fractal dimensions and properties of metal material surfaces and interfaces will be the key research direction of the fractal analysis of metal materials in the future.
