Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associat...Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associated with the risk of collision with non-cooperative targets.This paper introduces a long-range,contactless method for identifying the inertial parameters of a non-cooperative target during the pre-capture phase.Specifically,electrostatic interaction is used as an external excitation to alter the target's motion.A force estimation algorithm that uses measure-ments from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors.Furthermore,a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state,weak electrostatic interaction,and inertial parameters of the target.The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identifica-tion precision forall parameters.展开更多
The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma g...The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma generation system depending on the duty rate,as well as the pulse repetition rate,are presented.The operating modes of the system have been established,in which a minimum of energy consumption is achieved.The issues of evaluating the interaction of plasma with objects based on the analysis of changes in signal parameters in the high-voltage circuit of the generator are also considered.展开更多
The tensile-shear interactive damage(TSID)model is a novel and powerful constitutive model for rock-like materials.This study proposes a methodology to calibrate the TSID model parameters to simulate sandstone.The bas...The tensile-shear interactive damage(TSID)model is a novel and powerful constitutive model for rock-like materials.This study proposes a methodology to calibrate the TSID model parameters to simulate sandstone.The basic parameters of sandstone are determined through a series of static and dynamic tests,including uniaxial compression,Brazilian disc,triaxial compression under varying confining pressures,hydrostatic compression,and dynamic compression and tensile tests with a split Hopkinson pressure bar.Based on the sandstone test results from this study and previous research,a step-by-step procedure for parameter calibration is outlined,which accounts for the categories of the strength surface,equation of state(EOS),strain rate effect,and damage.The calibrated parameters are verified through numerical tests that correspond to the experimental loading conditions.Consistency between numerical results and experimental data indicates the precision and reliability of the calibrated parameters.The methodology presented in this study is scientifically sound,straightforward,and essential for improving the TSID model.Furthermore,it has the potential to contribute to other rock constitutive models,particularly new user-defined models.展开更多
An approach of describing the thermodynamics of binary alloys is developed which is based on an exact expression of infinite MacLaurin series of molar excess Gibbs free energy. This new approach is successfully used t...An approach of describing the thermodynamics of binary alloys is developed which is based on an exact expression of infinite MacLaurin series of molar excess Gibbs free energy. This new approach is successfully used to represent the thermodynamics of binary alloys at higher concentrations. The present results reveal that it is an improper way to evaluate first and second-order interaction parameters simultaneously from the experimental data in the range of higher concentrations due to an inadequate accuracy Of high temperature experiments.展开更多
In this article, we consider the blowup criterion for the local strong solution to the compressible fluid-particle interaction model in dimension three with vacuum. We establish a BKM type criterion for possible break...In this article, we consider the blowup criterion for the local strong solution to the compressible fluid-particle interaction model in dimension three with vacuum. We establish a BKM type criterion for possible breakdown of such solutions at critical time in terms of both the L^∞ （0, T; L^6）-norm of the density of particles and the ^L1（0, T; L^∞）-norm of the deformation tensor of velocity gradient.展开更多
Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararnet...Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararneters in this article. Based on these extending methods, the effect of varying freshwater consumption and regenerated water flow rate on the optimizing results are investigated. The interactions of parameters of regeneration recycling systems are summarized. Finally, all the conclusions are illustrated from the results of mathematical programming through an example.展开更多
Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC)+ ethylene carbonate and methanol + ethylene carbonate at 101.325kPa. The thermodynamic consistency ...Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC)+ ethylene carbonate and methanol + ethylene carbonate at 101.325kPa. The thermodynamic consistency of these experimental data is tested with an available statistic method. Interaction parameters of the carbonate group -OCOO- with the group -CH3, ACH, CH3OH and CH3COO- in UNIFAC model are determined using the experimental and literature VLE data. The results show that the calculated VLE data using the new UNIFAC parameters agree excellently with the experimental data in this work and in literature. These results are useful in the research on DMC and diphenyl carbonate synthesis by transesterification in design of reactor and distillation tower.展开更多
The substantial increase in the efficiency of organic solar cells achieved in recent years would not have been possible without work on the synthesis of new materials and understanding the relationship between the mor...The substantial increase in the efficiency of organic solar cells achieved in recent years would not have been possible without work on the synthesis of new materials and understanding the relationship between the morphology and performance of organic photovoltaic devices.The structure of solvent-cast active layers is a result of phase separation in mixtures of donor and acceptor components.To a large extent,this process depends on the interactions between the components of the mixture.Here,we present a systematic analysis of the morphology of poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)](PCDTBT)and[6,6]-phenyl-C71-butyric acid methyl ester(PC70BM)films in terms of the ternary phase diagram.The interaction parameters between PCDTBT and four different solvents,namely chloroform,chlorobenzene,o-dichlorobenzene,and toluene,were estimated based on swelling experiments.Based on these values,ternary phase diagrams of PCDTBT:PC70BM in different solvents were calculated.The morphology of spin-coated films with different blend ratios cast from different solvents is discussed in terms of the obtained phase diagrams.展开更多
Robust Parameter Design(RPD) has been widely applied for improving quality and reliability of products.One of the key drawbacks of applying RPD using Taguchi method is that the stable factors may not be independent of...Robust Parameter Design(RPD) has been widely applied for improving quality and reliability of products.One of the key drawbacks of applying RPD using Taguchi method is that the stable factors may not be independent of the adjustment factors, resulting in unsatisfactory design.Moreover, the Taguchi method cannot guarantee global optimality since the levels set in the experiment are usually discrete to ensure orthogonal design.In this paper, robust solutions of the stable factors are obtained via a nonlinear model based on polynomial fitting;while the adjustment factors are obtained via interactions analysis so that they are independent of the stable factors.In particular, the values of the adjustment factors are determined by output offset compensation so as to achieve robustness of the design scheme.An example on the design of an aeronautical electrical apparatus is presented to illustrate the procedure.The results show that the proposed method can take full advantage of the nonlinearity in the response and achieve the desired outcome.展开更多
In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpr...In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows:Gm^E=xAxB[(λ11+λ12T)+(λ21+λ22T)xB]The calculation of the model parameters, λ11, λ12, λ21and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the .calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model.展开更多
The molecular interaction volume model （MIVM） for a general ternary system was deduced in detail for further clarifying and understanding its general multicomponent expression. Both MIVM and the unified interaction ...The molecular interaction volume model （MIVM） for a general ternary system was deduced in detail for further clarifying and understanding its general multicomponent expression. Both MIVM and the unified interaction parameter formalism （UIPF） can be used to predict the activities of solutes and solvents in the Fe-Cr-Ni liquid alloys. But the former employs only the infinite dilute activity coefficients, and the later is not applicable without the dilute binary and ternary interaction parameters. MIVM has a certain physical meaning from the viewpoint of statistical thermodynamics, so it is an alternative for the estimation of activity coefficients of the solutes and solvents in a dilute or finite concentration metal solution where the interaction parameters are absent or their accuracies are questionable.展开更多
Entropic contribution to the interaction parameter (?) in the model incompressible polymer/oligomer system iscalculated by the lattice cluster theory(LCT).It is found that in the oligomer solvent,there exists a wide c...Entropic contribution to the interaction parameter (?) in the model incompressible polymer/oligomer system iscalculated by the lattice cluster theory(LCT).It is found that in the oligomer solvent,there exists a wide concentration rangethat the non-combinatorial“entropic interaction”term (?)φ_1φ_2 perceptibly counteracts the mean field combinary entropy△S_(MF).With the increase of the solvent size,both (?) and the ratio (?)φ_1φ_2/△S_(MF) first reach their maximum and finallybecome trivially to zero.It is worth noting that no any demixing was found in the current calculation.This makes thecontroversial idea“entropically driven demixing”even elusive.However,we propose that further work on compressiblepolymer solution with structured monomer will witness the demixing owning to an increased configurational correlation.展开更多
Carbon solubility in Fe-Mn melts （XFe =0. 102 3-0. 789 9, XMn =0. 055 1-0. 638 0） was measured experimentally at various temperatures. Using Gibbs-Duhem equation, in combination with the experimental results in this...Carbon solubility in Fe-Mn melts （XFe =0. 102 3-0. 789 9, XMn =0. 055 1-0. 638 0） was measured experimentally at various temperatures. Using Gibbs-Duhem equation, in combination with the experimental results in this work, quoting experimental data reported in references, and by strict thermodynamic derivation and calculation, the relation equations between the activity interaction parameters in Fe-C system and temperature were obtained. The calculation equation of lnyFe. in Fe-C system was also obtained. The calculated results show that these relation equations can be used to calculate the activity coefficients of carbon and iron in Fe-C system and can satisfy the necessary condition to satisfy Gibbs-Duhem equation and the necessary condition to satisfy the stability condition of system at high carbon content. The calculation formula for lnTc in Fe-Mn-C system was also obtained.展开更多
The time domain parameter laenuncauon memoa oi me iounuauon-structure interaction system is presented. On the basis of building the computation mode and the motion equation of the foundation-structure interaction syst...The time domain parameter laenuncauon memoa oi me iounuauon-structure interaction system is presented. On the basis of building the computation mode and the motion equation of the foundation-structure interaction system, the system parameter identification method was established by using the extended Kalman filter （EKF） technique and taking the unknown parameters in the system as the augment state variables. And the time parameter identification process of the foundation-structure interaction system was implemented by using the data of the layer foundation-storehouse interaction system model test on the large vibration platform. The computation result shows that the established parameter identification method can induce good parameter estimation.展开更多
The interaction parameters of Nb in Fe-C-Nb melts at 1873 K were measured using the chemical equilibrium method.The Fe-C melts were equilibrated with the CaO-MgO-Al_(2)O_(3)-NbO_(2) slags under a controlled oxygen pot...The interaction parameters of Nb in Fe-C-Nb melts at 1873 K were measured using the chemical equilibrium method.The Fe-C melts were equilibrated with the CaO-MgO-Al_(2)O_(3)-NbO_(2) slags under a controlled oxygen potential for 24 h.In addition to acting as the protective gas,argon was adopted to control the oxygen potential.Based on the data obtained in the experiments,the activity interaction parameters were obtained by the multiple linear regression method.The first-order interaction parameters e_(Nb)^(C)and e_(Nb)^(Nb)are determined to be−0.035 and−0.134,respectively.The second-order interaction parameters r_(Nb)^(C),r_(Nb)^(Nb,C),and r_(Nb)……(Nb)are determined to be 0.011,−0.0063,and 0.0023,respectively.The thermodynamic data obtained are more reliable than those in previous publications for the Fe-C-Nb system when the Nb content range was 0.92-4.62 wt.%.展开更多
The artificial neural network method has been applied to the relationship between the atomic parameters and intemction packeters of binary alloy Phases, and the principle of thermodynamics in combination with artifici...The artificial neural network method has been applied to the relationship between the atomic parameters and intemction packeters of binary alloy Phases, and the principle of thermodynamics in combination with artificial neural network method has been used for the computerized phase diagrams of continuous solid solution of bigamy alloy systems. The computerized phase diagrams well agree with the real phase diagmms.展开更多
Fluid-particle interaction underpins important behavior of granular media. Particle-scale simulation may help to provide key microscopic information governing the interaction and offer better understanding of granular...Fluid-particle interaction underpins important behavior of granular media. Particle-scale simulation may help to provide key microscopic information governing the interaction and offer better understanding of granular media as a whole. This paper presents a coupled computational fluid dynamics and discrete element method （CFD-DEM） approach for this purpose. The granular particle system is modeled by DEM, while the fluid flow is simulated by solving the locally averaged Navier-Stokes equation with CFD. The coupling is considered by exchanging such interaction forces as drag force and buoyancy force between the DEM and CFD. The approach is benchmarked by two classic geomechanics problems for which analytical solutions are available, and is further applied to the prediction of sand heap formation in water through hopper flow. It is demonstrated that the key characteristic of granular materials interacting with pore water can be successfully captured by the proposed method.展开更多
The paper investigates the second-order interactions of parameters in an alkali-activated mixture of paper production waste(PPW)and blast furnace slag(BFS)in Taguchi method.The PPW including lime mud(LM)and paper slud...The paper investigates the second-order interactions of parameters in an alkali-activated mixture of paper production waste(PPW)and blast furnace slag(BFS)in Taguchi method.The PPW including lime mud(LM)and paper sludge(PS).This paper provides the experimental models to assess the compressive and flexural strength of them at 7-day and 28-day.The results have shown that the second-order interactions between PPW and alkali-activated activator exists in each experimental model,and the significant interactions affect the selection of optimal compositions.Compared with the interactions between the PPW themselves,the interactions between PPW and alkali-activated parameters are the main significant factors affecting its physical properties.In each experimental model,the maximum compressive strength was 47.41 MPa in 7-day and 65.64 MPa in 28-day.Compared with the confirmatory experiments,the deviation of prediction calculated by experimental models was 3.08%and 0.56%,respectively.The maximum flexural strength was 5.74 MPa in 7-day and 5.96 MPa in 28-day;compared with the confirmatory experiments,the deviation of prediction calculated by experimental models was 5.40%and 0.17%.Considering the influence of circular materials,30%of PPW should be a suitable ratio to replace BFS as the raw material of alkali-activated slag(AAS).展开更多
Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modifi...Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modified UNIFAC model for the improvement of predicting vapor-liquid equilibria. The predictions of vapor-liquid equilibria for 62 systems including alcohol- alkane, alcohol-benzene, and amine-water systems demonstrate that the revised parameters remarkably improve the prediction accuracy for many systems. Especially for amine-water system, the mean deviation of components decreases from 0.094 to 0.021, and the mean deviation of pressure from 22.45% to 4.41%.展开更多
Blends of polyacrylamide—PAM, poly(N-isopropylacrylamide)—PNIPAAm, poly(N-tert-butylacrylamide)—PTBAA, poly(N,N-dimethylacrylamide)—PDMAA and poly(N,N-diethylacrylamide)—PDEAA with poly(ethylene glycol)— PEG wer...Blends of polyacrylamide—PAM, poly(N-isopropylacrylamide)—PNIPAAm, poly(N-tert-butylacrylamide)—PTBAA, poly(N,N-dimethylacrylamide)—PDMAA and poly(N,N-diethylacrylamide)—PDEAA with poly(ethylene glycol)— PEG were prepared by casting in methanol and water at concentrations of 20 wt%, 40 wt%, 60 wt%, and 80 wt% in PEG. The miscibility of the components was studied by Differential Scanning Calorimetry—DSC. All blend systems are characterized by a single glass transition temperature (Tg), close to the Tg of the amorphous component. The Hoffman Weeks method was used to determine equilibrium melting temperature (Tm) data. The determination of the melt point depression of the blends allowed the calculation of Flory-Huggins interaction parameter (χ12) of the two polymers in the melt, by using the Nishi Wang equation. The interaction parameters, calculated for all the blends, are slightly negative and close to zero, suggesting a partial miscibility between the components.展开更多
基金supported by the National Natural Science Foundation of China(No.6200326).
文摘Inertial characteristics of non-cooperative targets are crucial for space capture and sub-sequent on-orbit servicing.Previous methods for identifying inertial parameters involve proximity operations,which are associated with the risk of collision with non-cooperative targets.This paper introduces a long-range,contactless method for identifying the inertial parameters of a non-cooperative target during the pre-capture phase.Specifically,electrostatic interaction is used as an external excitation to alter the target's motion.A force estimation algorithm that uses measure-ments from visual and potential sensors is proposed to estimate the electrostatic interaction and eliminate the need for force sensors.Furthermore,a recursive estimation-identification framework is presented to concurrently estimate the coupled motion state,weak electrostatic interaction,and inertial parameters of the target.The simulation results show that the proposed method extends the identification distance to 170 times that of the previous method while maintaining high identifica-tion precision forall parameters.
文摘The article discusses the use of pulse-width modulation signals to generate low-temperature atmospheric plasma in an inert gas environment.The results of studies of the energy consumption of a low-temperature plasma generation system depending on the duty rate,as well as the pulse repetition rate,are presented.The operating modes of the system have been established,in which a minimum of energy consumption is achieved.The issues of evaluating the interaction of plasma with objects based on the analysis of changes in signal parameters in the high-voltage circuit of the generator are also considered.
基金funded by the National Natural Science Foundation of China(Grant No.12272247)National Key Project(Grant No.GJXM92579)Major Research and Development Project of Metallurgical Corporation of China Ltd.in the Non-Steel Field(Grant No.2021-5).
文摘The tensile-shear interactive damage(TSID)model is a novel and powerful constitutive model for rock-like materials.This study proposes a methodology to calibrate the TSID model parameters to simulate sandstone.The basic parameters of sandstone are determined through a series of static and dynamic tests,including uniaxial compression,Brazilian disc,triaxial compression under varying confining pressures,hydrostatic compression,and dynamic compression and tensile tests with a split Hopkinson pressure bar.Based on the sandstone test results from this study and previous research,a step-by-step procedure for parameter calibration is outlined,which accounts for the categories of the strength surface,equation of state(EOS),strain rate effect,and damage.The calibrated parameters are verified through numerical tests that correspond to the experimental loading conditions.Consistency between numerical results and experimental data indicates the precision and reliability of the calibrated parameters.The methodology presented in this study is scientifically sound,straightforward,and essential for improving the TSID model.Furthermore,it has the potential to contribute to other rock constitutive models,particularly new user-defined models.
文摘An approach of describing the thermodynamics of binary alloys is developed which is based on an exact expression of infinite MacLaurin series of molar excess Gibbs free energy. This new approach is successfully used to represent the thermodynamics of binary alloys at higher concentrations. The present results reveal that it is an improper way to evaluate first and second-order interaction parameters simultaneously from the experimental data in the range of higher concentrations due to an inadequate accuracy Of high temperature experiments.
基金supported by the National Basic Research Program of China(973 Program)(2011CB808002)the National Natural Science Foundation of China(11371152,11128102,11071086,and 11571117)+3 种基金the Natural Science Foundation of Guangdong Province(S2012010010408)the Foundation for Distinguished Young Talents in Higher Education of Guangdong(2015KQNCX095)the Major Foundation of Hanshan Normal University(LZ201403)the Scientific Research Foundation of Graduate School of South China Normal University(2014ssxm04)
文摘In this article, we consider the blowup criterion for the local strong solution to the compressible fluid-particle interaction model in dimension three with vacuum. We establish a BKM type criterion for possible breakdown of such solutions at critical time in terms of both the L^∞ （0, T; L^6）-norm of the density of particles and the ^L1（0, T; L^∞）-norm of the deformation tensor of velocity gradient.
基金Supported by the National Natural Science Foundation of China （No.20436040）.
文摘Method for constructing the optimal water supply line and formulas for calculating the targets for single-contaminant regeneration recycling water systems are improved to apply to the situation of variational pararneters in this article. Based on these extending methods, the effect of varying freshwater consumption and regenerated water flow rate on the optimizing results are investigated. The interactions of parameters of regeneration recycling systems are summarized. Finally, all the conclusions are illustrated from the results of mathematical programming through an example.
文摘Isobaric vapor-liquid equilibria (VLE) are experimentally measured for the binary systems of dimethyl carbonate (DMC)+ ethylene carbonate and methanol + ethylene carbonate at 101.325kPa. The thermodynamic consistency of these experimental data is tested with an available statistic method. Interaction parameters of the carbonate group -OCOO- with the group -CH3, ACH, CH3OH and CH3COO- in UNIFAC model are determined using the experimental and literature VLE data. The results show that the calculated VLE data using the new UNIFAC parameters agree excellently with the experimental data in this work and in literature. These results are useful in the research on DMC and diphenyl carbonate synthesis by transesterification in design of reactor and distillation tower.
基金the National Science Center(No.UMO-2013/11/B/ST5/04473)the European Regional Development Fund in the framework of the Polish Innovation Economy Operational Program(Contract No.POIG.02.01.00-12-023/08).
文摘The substantial increase in the efficiency of organic solar cells achieved in recent years would not have been possible without work on the synthesis of new materials and understanding the relationship between the morphology and performance of organic photovoltaic devices.The structure of solvent-cast active layers is a result of phase separation in mixtures of donor and acceptor components.To a large extent,this process depends on the interactions between the components of the mixture.Here,we present a systematic analysis of the morphology of poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)](PCDTBT)and[6,6]-phenyl-C71-butyric acid methyl ester(PC70BM)films in terms of the ternary phase diagram.The interaction parameters between PCDTBT and four different solvents,namely chloroform,chlorobenzene,o-dichlorobenzene,and toluene,were estimated based on swelling experiments.Based on these values,ternary phase diagrams of PCDTBT:PC70BM in different solvents were calculated.The morphology of spin-coated films with different blend ratios cast from different solvents is discussed in terms of the obtained phase diagrams.
基金co-supported by the National Natural Science Foundation of China(Nos.51707044 and 61671172)the China Postdoctoral Science Foundation(No.2018M632377)。
文摘Robust Parameter Design(RPD) has been widely applied for improving quality and reliability of products.One of the key drawbacks of applying RPD using Taguchi method is that the stable factors may not be independent of the adjustment factors, resulting in unsatisfactory design.Moreover, the Taguchi method cannot guarantee global optimality since the levels set in the experiment are usually discrete to ensure orthogonal design.In this paper, robust solutions of the stable factors are obtained via a nonlinear model based on polynomial fitting;while the adjustment factors are obtained via interactions analysis so that they are independent of the stable factors.In particular, the values of the adjustment factors are determined by output offset compensation so as to achieve robustness of the design scheme.An example on the design of an aeronautical electrical apparatus is presented to illustrate the procedure.The results show that the proposed method can take full advantage of the nonlinearity in the response and achieve the desired outcome.
文摘In this paper, the interaction parameters in the subregular solution model, λ1 and λ2, are regarded as a linear function of temperature, T. Therefore, the molar excess Gibbs energy of A-B binary system may be reexpressed as follows:Gm^E=xAxB[(λ11+λ12T)+(λ21+λ22T)xB]The calculation of the model parameters, λ11, λ12, λ21and λ22, was carried out numerically from the phase diagrams for 11 alkali metal-alkali halide or alkali earth metal-halide systems. In addition, artificial neural network trained by known data has been used to predict the values of these model parameters. The predicted results are in good agreement with the .calculated ones. The applicability of the subregular solution model to the alkali metal-alkali halide or alkali earth metal-halide systems were tested by comparing the available experimental composition along the boundary of miscibility gap with the calculated ones which were obtained by using genetic algorithm. The good agreement between the calculated and experimental results across the entire liquidus is valid evidence in support of the model.
基金This work was supported by the Joint Fund of the National Natural Science Foundation of China the Shanghai Baoshan Steel Complex under Grant No. 50274039.
文摘The molecular interaction volume model （MIVM） for a general ternary system was deduced in detail for further clarifying and understanding its general multicomponent expression. Both MIVM and the unified interaction parameter formalism （UIPF） can be used to predict the activities of solutes and solvents in the Fe-Cr-Ni liquid alloys. But the former employs only the infinite dilute activity coefficients, and the later is not applicable without the dilute binary and ternary interaction parameters. MIVM has a certain physical meaning from the viewpoint of statistical thermodynamics, so it is an alternative for the estimation of activity coefficients of the solutes and solvents in a dilute or finite concentration metal solution where the interaction parameters are absent or their accuracies are questionable.
基金This work was support by the National Natural Science Foundation of China(NSFC,No.2037402790103036).
文摘Entropic contribution to the interaction parameter (?) in the model incompressible polymer/oligomer system iscalculated by the lattice cluster theory(LCT).It is found that in the oligomer solvent,there exists a wide concentration rangethat the non-combinatorial“entropic interaction”term (?)φ_1φ_2 perceptibly counteracts the mean field combinary entropy△S_(MF).With the increase of the solvent size,both (?) and the ratio (?)φ_1φ_2/△S_(MF) first reach their maximum and finallybecome trivially to zero.It is worth noting that no any demixing was found in the current calculation.This makes thecontroversial idea“entropically driven demixing”even elusive.However,we propose that further work on compressiblepolymer solution with structured monomer will witness the demixing owning to an increased configurational correlation.
基金Item Sponsored by National Natural Science Foundation of China (50374002)
文摘Carbon solubility in Fe-Mn melts （XFe =0. 102 3-0. 789 9, XMn =0. 055 1-0. 638 0） was measured experimentally at various temperatures. Using Gibbs-Duhem equation, in combination with the experimental results in this work, quoting experimental data reported in references, and by strict thermodynamic derivation and calculation, the relation equations between the activity interaction parameters in Fe-C system and temperature were obtained. The calculation equation of lnyFe. in Fe-C system was also obtained. The calculated results show that these relation equations can be used to calculate the activity coefficients of carbon and iron in Fe-C system and can satisfy the necessary condition to satisfy Gibbs-Duhem equation and the necessary condition to satisfy the stability condition of system at high carbon content. The calculation formula for lnTc in Fe-Mn-C system was also obtained.
文摘The time domain parameter laenuncauon memoa oi me iounuauon-structure interaction system is presented. On the basis of building the computation mode and the motion equation of the foundation-structure interaction system, the system parameter identification method was established by using the extended Kalman filter （EKF） technique and taking the unknown parameters in the system as the augment state variables. And the time parameter identification process of the foundation-structure interaction system was implemented by using the data of the layer foundation-storehouse interaction system model test on the large vibration platform. The computation result shows that the established parameter identification method can induce good parameter estimation.
基金support of this research by the National Natural Science Foundation of China(Grant Nos.51774025,51534001)Fundamental Research Funds for the Central Universities(Grant No.FRF-TP-20-009A1).
文摘The interaction parameters of Nb in Fe-C-Nb melts at 1873 K were measured using the chemical equilibrium method.The Fe-C melts were equilibrated with the CaO-MgO-Al_(2)O_(3)-NbO_(2) slags under a controlled oxygen potential for 24 h.In addition to acting as the protective gas,argon was adopted to control the oxygen potential.Based on the data obtained in the experiments,the activity interaction parameters were obtained by the multiple linear regression method.The first-order interaction parameters e_(Nb)^(C)and e_(Nb)^(Nb)are determined to be−0.035 and−0.134,respectively.The second-order interaction parameters r_(Nb)^(C),r_(Nb)^(Nb,C),and r_(Nb)……(Nb)are determined to be 0.011,−0.0063,and 0.0023,respectively.The thermodynamic data obtained are more reliable than those in previous publications for the Fe-C-Nb system when the Nb content range was 0.92-4.62 wt.%.
文摘The artificial neural network method has been applied to the relationship between the atomic parameters and intemction packeters of binary alloy Phases, and the principle of thermodynamics in combination with artificial neural network method has been used for the computerized phase diagrams of continuous solid solution of bigamy alloy systems. The computerized phase diagrams well agree with the real phase diagmms.
基金supported by the Research Grants Council of Hong Kong (622910)
文摘Fluid-particle interaction underpins important behavior of granular media. Particle-scale simulation may help to provide key microscopic information governing the interaction and offer better understanding of granular media as a whole. This paper presents a coupled computational fluid dynamics and discrete element method （CFD-DEM） approach for this purpose. The granular particle system is modeled by DEM, while the fluid flow is simulated by solving the locally averaged Navier-Stokes equation with CFD. The coupling is considered by exchanging such interaction forces as drag force and buoyancy force between the DEM and CFD. The approach is benchmarked by two classic geomechanics problems for which analytical solutions are available, and is further applied to the prediction of sand heap formation in water through hopper flow. It is demonstrated that the key characteristic of granular materials interacting with pore water can be successfully captured by the proposed method.
基金This work was supported by Ministry of education of Taiwan(Grant No.H108-AA09)for funding,CHP for materials provision,and NCKU C-Hub for space and instruments.
文摘The paper investigates the second-order interactions of parameters in an alkali-activated mixture of paper production waste(PPW)and blast furnace slag(BFS)in Taguchi method.The PPW including lime mud(LM)and paper sludge(PS).This paper provides the experimental models to assess the compressive and flexural strength of them at 7-day and 28-day.The results have shown that the second-order interactions between PPW and alkali-activated activator exists in each experimental model,and the significant interactions affect the selection of optimal compositions.Compared with the interactions between the PPW themselves,the interactions between PPW and alkali-activated parameters are the main significant factors affecting its physical properties.In each experimental model,the maximum compressive strength was 47.41 MPa in 7-day and 65.64 MPa in 28-day.Compared with the confirmatory experiments,the deviation of prediction calculated by experimental models was 3.08%and 0.56%,respectively.The maximum flexural strength was 5.74 MPa in 7-day and 5.96 MPa in 28-day;compared with the confirmatory experiments,the deviation of prediction calculated by experimental models was 5.40%and 0.17%.Considering the influence of circular materials,30%of PPW should be a suitable ratio to replace BFS as the raw material of alkali-activated slag(AAS).
文摘Quantitative description of vapor-liquid equilibrium is very useful for designing separation processes. In this study, we combined the Peng-Robinson equation and the Huron-Vidal-Orbey-Sandler mixing rule into a modified UNIFAC model for the improvement of predicting vapor-liquid equilibria. The predictions of vapor-liquid equilibria for 62 systems including alcohol- alkane, alcohol-benzene, and amine-water systems demonstrate that the revised parameters remarkably improve the prediction accuracy for many systems. Especially for amine-water system, the mean deviation of components decreases from 0.094 to 0.021, and the mean deviation of pressure from 22.45% to 4.41%.
基金the Brazilian Agencies CNPq,CAPES and FAPEMIG for financial support.
文摘Blends of polyacrylamide—PAM, poly(N-isopropylacrylamide)—PNIPAAm, poly(N-tert-butylacrylamide)—PTBAA, poly(N,N-dimethylacrylamide)—PDMAA and poly(N,N-diethylacrylamide)—PDEAA with poly(ethylene glycol)— PEG were prepared by casting in methanol and water at concentrations of 20 wt%, 40 wt%, 60 wt%, and 80 wt% in PEG. The miscibility of the components was studied by Differential Scanning Calorimetry—DSC. All blend systems are characterized by a single glass transition temperature (Tg), close to the Tg of the amorphous component. The Hoffman Weeks method was used to determine equilibrium melting temperature (Tm) data. The determination of the melt point depression of the blends allowed the calculation of Flory-Huggins interaction parameter (χ12) of the two polymers in the melt, by using the Nishi Wang equation. The interaction parameters, calculated for all the blends, are slightly negative and close to zero, suggesting a partial miscibility between the components.
