Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)an...Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.展开更多
Liquid metal alloys(LMAs) are the potential candidates of thermal interface materials(TIMs) for electronics cooling.In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates ...Liquid metal alloys(LMAs) are the potential candidates of thermal interface materials(TIMs) for electronics cooling.In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates by DC magnetron sputtering, the contact angles of de-ionized water and diiodomethane on the buffer layers were measured by an easy drop shape analyzer and the surface free energies(SFEs) of the buffer layers were calculated by the Owens–Wendt–Kaelble equation. Samples were prepared by sandwiching the filmed Cu plates and LMAs. The thermal properties of the samples were measured by laser flash analysis method. The SFE of the buffer layer has a strong influence on the interface heat transfer, whereas the measurement temperature has no obvious effect on the thermal properties of the samples. As the SFE of the buffer layer increases, the wettability, thermal diffusivity, and thermal conductivity are enhanced, and the thermal contact resistance is decreased.展开更多
A new equation for predicting surface tension is proposed based on the thermodynamic definition of surface tension and the expression of the Gibbs free energy of the system. Using the NRTL equation to represent the ex...A new equation for predicting surface tension is proposed based on the thermodynamic definition of surface tension and the expression of the Gibbs free energy of the system. Using the NRTL equation to represent the excess Gibbs free energy, a two-parameter surface tension equation is derived. The feasibility of the new equation has been tested in terms of 124 binary and 16 multicomponent systems(13-ternary and 3-quaternary) with absolute relative deviations of 0.59% and 1.55% respectively. This model is also predictive for the temperature dependence of surface tension of liquid mixtures. It is shown that, with good accuracy, this equation is simple and reliable for practical use.展开更多
Discriminating between different liquids using surfaces with special wettability holds significant implications for both fundamental research and practical applications.However,current differentiation surfaces still s...Discriminating between different liquids using surfaces with special wettability holds significant implications for both fundamental research and practical applications.However,current differentiation surfaces still struggle with challenges such as complex microstructure design,a limited detection range,and poor stability.In this study,we present a new platform for droplet discrimination achieved through a combination of groove structures and a liquid-like polydimethylsiloxane(PDMS)brushes coating.The PDMS brushes coating exhibits excellent stability and low adhesion across a wide range of liquids with surface tensions ranging from 27.5 to 72.8 mN/m,while the groove structure provides distinct energy barriers for droplet sliding.Consequently,liquids with varying surface tensions can be effectively discriminated,as evidenced by the increased sliding angles(SAs)observed as liquids with lower surface tension moving across the groove.Furthermore,we utilized a three dimensional(3D)model of the droplet developed using Surface Evolver,and conducted energy variation calculations during droplet sliding across the groove to analyze the SA differences among liquids with different surface tensions.Additionally,we proposed two simple differentiation platforms that successfully demonstrated effective droplet discrimination.This work introduces a novel strategy for droplet discrimination,offering innovative ideas for the design of functional surfaces.These findings may potentially be applied in other fields involving droplet manipulation,such as droplet-based microchemical reactions and bio-detection.展开更多
Liquid marbles （non-stick droplets） containing crude petroleum are reported. Liquid marbles were ob- tained by use of fluorinated decyl polyhedral oligomeric silsequioxane （FD-POSS） powder. Marbles containing crud...Liquid marbles （non-stick droplets） containing crude petroleum are reported. Liquid marbles were ob- tained by use of fluorinated decyl polyhedral oligomeric silsequioxane （FD-POSS） powder. Marbles containing crude petroleum remained stable on a broad diversity of solid and liquid supports. The effective surface tension of marbles filled with petroleum was established. The mechanism of friction of the marbles is discussed. Actuation of liquid marbles containing crude petroleum with an electric field is presented.展开更多
The values of density and surface tension for aqueous solution of ionic liquid（IL） 1-butyl-3-methylimi- dazolium acetate（[C4nim][OAc]） with various molalities were measured in the range of 288.15--318.15 K at inte...The values of density and surface tension for aqueous solution of ionic liquid（IL） 1-butyl-3-methylimi- dazolium acetate（[C4nim][OAc]） with various molalities were measured in the range of 288.15--318.15 K at intervals of 5 K. On the basis of thermodynamics, a semi-empirical model-molar surface Gibbs energy model of the ionic liquid solution that could be used to predict the surface tension or molar volume of solutions was put forward. The predicted values of the surface tension for aqueous [C4mim][OAc] and the corresponding experimental ones were highly correlated and extremely similar. In terms of the concept of the molar Gibbs energy, a new Eotvos equation was obtained and each parameter of the new equation has a clear physical meaning.展开更多
Numerical simulations have been carded out for two-dimensional wavy falling liquid film in order to investigate kinetic energy and surface energy of that liquid film. Governing equations, which are continuity equation...Numerical simulations have been carded out for two-dimensional wavy falling liquid film in order to investigate kinetic energy and surface energy of that liquid film. Governing equations, which are continuity equation, Na-, vier-Stokes equation, and equations of interfacial boundary conditions including surface movement and effect of surface tension, have been solved directly by means of a numerical scheme based on the finite difference method. In most cases, periodic disturbances superimposed at inflow boundary grow to fully developed waves Which retain the given periodic behavior. In some cases, however, random waves appear after the fully developed waves. Variations of kinetic energy and surface energy of the periodically developed waves and the random waves have been discussed.展开更多
The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an AI-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus. The Gibbs Thomson coefficient, solid...The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an AI-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus. The Gibbs Thomson coefficient, solid liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes. The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag2Al-28.3 at the %CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus, separately.展开更多
The objective of this study was to investigate the surface free energy of poplar and yellow pine strands by Wilhelmy Plate Method. The measurement items included the surface contact angle, surface free energy and chan...The objective of this study was to investigate the surface free energy of poplar and yellow pine strands by Wilhelmy Plate Method. The measurement items included the surface contact angle, surface free energy and change of sample weight. Thirty industrial strands were randomly collected for each condition. The samples were cut down to 25.0-26.0 mm long, 7.0-8.0 mm wide. The density and thickness of each sample were also tested. The range of density was from 0.35 to 0.75 g/cm^3 and the range of thickness was from 0.5 to 1.0 ram. The research result shows that there is a close relationship between the wettability, mass change and moisture content. Both the density and the thickness of the strand have a small influence on the surface contact angle and the surface free energy.展开更多
基金the National Natural Science Foundation of China(Grant No.U20A2081)West Light Foundation of the Chinese Academy of Sciences(Grant No.xbzg-zdsys-202102)the Second Tibetan Plateau Scientific Expedition and Research(STEP)Project(Grant No.2019QZKK0105).
文摘Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling.This study emphasized the influence of the initial soil temperature(ST)and soil moisture(SM)conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau(TP)using the Community Land Model version 5.0(CLM5.0).The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic,and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site.Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes.The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost,which coexists with soil liquid water(SLW),and soil ice(SI)when the ST is below freezing temperature,effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes.Consequently,the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method.Three modified initial soil schemes experiments resulted in a 64%,88%,and 77%reduction in the average mean bias error(MBE)of ST,and a 13%,21%,and 19%reduction in the average root-mean-square error(RMSE)of SLW compared to the default simulation results.Also,the average MBE of net radiation was reduced by 7%,22%,and 21%.
基金Project supported by the National Natural Science Foundation of China(Grant No.11874191)the Natural Science Foundation of Shandong Province,China(Grant No.ZR2016FM38)
文摘Liquid metal alloys(LMAs) are the potential candidates of thermal interface materials(TIMs) for electronics cooling.In the present work, buffer layers of Ag, Ti, Cu, Ni, Mo, and W were deposited on polished Cu plates by DC magnetron sputtering, the contact angles of de-ionized water and diiodomethane on the buffer layers were measured by an easy drop shape analyzer and the surface free energies(SFEs) of the buffer layers were calculated by the Owens–Wendt–Kaelble equation. Samples were prepared by sandwiching the filmed Cu plates and LMAs. The thermal properties of the samples were measured by laser flash analysis method. The SFE of the buffer layer has a strong influence on the interface heat transfer, whereas the measurement temperature has no obvious effect on the thermal properties of the samples. As the SFE of the buffer layer increases, the wettability, thermal diffusivity, and thermal conductivity are enhanced, and the thermal contact resistance is decreased.
基金the Scientific Research Foundation of the State Education Ministry for Returned Overseas Chinese Scholar.
文摘A new equation for predicting surface tension is proposed based on the thermodynamic definition of surface tension and the expression of the Gibbs free energy of the system. Using the NRTL equation to represent the excess Gibbs free energy, a two-parameter surface tension equation is derived. The feasibility of the new equation has been tested in terms of 124 binary and 16 multicomponent systems(13-ternary and 3-quaternary) with absolute relative deviations of 0.59% and 1.55% respectively. This model is also predictive for the temperature dependence of surface tension of liquid mixtures. It is shown that, with good accuracy, this equation is simple and reliable for practical use.
基金supported by the National Natural Science Foundation of China(NSFC,22075061)State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(2022TS37)。
文摘Discriminating between different liquids using surfaces with special wettability holds significant implications for both fundamental research and practical applications.However,current differentiation surfaces still struggle with challenges such as complex microstructure design,a limited detection range,and poor stability.In this study,we present a new platform for droplet discrimination achieved through a combination of groove structures and a liquid-like polydimethylsiloxane(PDMS)brushes coating.The PDMS brushes coating exhibits excellent stability and low adhesion across a wide range of liquids with surface tensions ranging from 27.5 to 72.8 mN/m,while the groove structure provides distinct energy barriers for droplet sliding.Consequently,liquids with varying surface tensions can be effectively discriminated,as evidenced by the increased sliding angles(SAs)observed as liquids with lower surface tension moving across the groove.Furthermore,we utilized a three dimensional(3D)model of the droplet developed using Surface Evolver,and conducted energy variation calculations during droplet sliding across the groove to analyze the SA differences among liquids with different surface tensions.Additionally,we proposed two simple differentiation platforms that successfully demonstrated effective droplet discrimination.This work introduces a novel strategy for droplet discrimination,offering innovative ideas for the design of functional surfaces.These findings may potentially be applied in other fields involving droplet manipulation,such as droplet-based microchemical reactions and bio-detection.
基金made to the Donors of the American Chemical Society Petroleum Research Fund for support of this research(Grant 52043-UR5)
文摘Liquid marbles （non-stick droplets） containing crude petroleum are reported. Liquid marbles were ob- tained by use of fluorinated decyl polyhedral oligomeric silsequioxane （FD-POSS） powder. Marbles containing crude petroleum remained stable on a broad diversity of solid and liquid supports. The effective surface tension of marbles filled with petroleum was established. The mechanism of friction of the marbles is discussed. Actuation of liquid marbles containing crude petroleum with an electric field is presented.
基金Supported by the National Natural Science Foundation of China（Nos.21273003, 21173107）, the Education Bureau of Liaoning Province, China（No.LJQ 2013001） and the Liaoning Baiqianwan Talents Program, China（No.2013921029）.
文摘The values of density and surface tension for aqueous solution of ionic liquid（IL） 1-butyl-3-methylimi- dazolium acetate（[C4nim][OAc]） with various molalities were measured in the range of 288.15--318.15 K at intervals of 5 K. On the basis of thermodynamics, a semi-empirical model-molar surface Gibbs energy model of the ionic liquid solution that could be used to predict the surface tension or molar volume of solutions was put forward. The predicted values of the surface tension for aqueous [C4mim][OAc] and the corresponding experimental ones were highly correlated and extremely similar. In terms of the concept of the molar Gibbs energy, a new Eotvos equation was obtained and each parameter of the new equation has a clear physical meaning.
文摘Numerical simulations have been carded out for two-dimensional wavy falling liquid film in order to investigate kinetic energy and surface energy of that liquid film. Governing equations, which are continuity equation, Na-, vier-Stokes equation, and equations of interfacial boundary conditions including surface movement and effect of surface tension, have been solved directly by means of a numerical scheme based on the finite difference method. In most cases, periodic disturbances superimposed at inflow boundary grow to fully developed waves Which retain the given periodic behavior. In some cases, however, random waves appear after the fully developed waves. Variations of kinetic energy and surface energy of the periodically developed waves and the random waves have been discussed.
基金supported by the Scientific and Technical Research Council of Turkey (TBTAK (Grant No 105T481)
文摘The equilibrated grain boundary groove shapes of solid solution Ag2Al in equilibrium with an AI-Cu-Ag liquid were observed from a quenched sample with a radial heat flow apparatus. The Gibbs Thomson coefficient, solid liquid interfacial energy and grain boundary energy of the solid solution Ag2Al have been determined from the observed grain boundary groove shapes. The thermal conductivity of the solid phase and the thermal conductivity ratio of the liquid phase to solid phase for Ag2Al-28.3 at the %CuAl2 alloy at the melting temperature have also been measured with a radial heat flow apparatus and Bridgman type growth apparatus, separately.
基金This study is supported by the project of natural science basic research in Jiangsu universities under Contact Number 05KJA22019,namely research on the properties modification of fast-growing poplar wood.
文摘The objective of this study was to investigate the surface free energy of poplar and yellow pine strands by Wilhelmy Plate Method. The measurement items included the surface contact angle, surface free energy and change of sample weight. Thirty industrial strands were randomly collected for each condition. The samples were cut down to 25.0-26.0 mm long, 7.0-8.0 mm wide. The density and thickness of each sample were also tested. The range of density was from 0.35 to 0.75 g/cm^3 and the range of thickness was from 0.5 to 1.0 ram. The research result shows that there is a close relationship between the wettability, mass change and moisture content. Both the density and the thickness of the strand have a small influence on the surface contact angle and the surface free energy.
