Poly(1-butyl-3-vinylimidazolium bromide)is a polymerized ionic liquid(PILs),a relatively new class of materials that combines the attractive properties of ionic liquids(ILs)and polyelectrolytes and finds wide applicat...Poly(1-butyl-3-vinylimidazolium bromide)is a polymerized ionic liquid(PILs),a relatively new class of materials that combines the attractive properties of ionic liquids(ILs)and polyelectrolytes and finds wide applications.The backbone of this PIL is composed of quaternary imidazolium salts,which are among the most promising and popular ILs.However,little is known about the physicochemical characteristics of the aqueous solutions of this PIL.In this study,we synthesized and characterized samples of this PIL and obtained experimental data on the viscosity,static and dynamic light scattering,and nuclear magnetic resonance diffusometry for aqueous and aqueous KBr solutions with varying polymer contents at T=298.15 K.We discuss the effects of the polymer concentration and salinity on the behavior of the solution.展开更多
In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar perce...In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.展开更多
The viscosity of refining slags plays a critical role in metallurgical processes.However,obtaining accurate viscosity data remains challenging due to the complexities of high-temperature experiments,often relying on e...The viscosity of refining slags plays a critical role in metallurgical processes.However,obtaining accurate viscosity data remains challenging due to the complexities of high-temperature experiments,often relying on empirical models with limited predictive capabilities.This study focuses on the influence of optical basicity on viscosity in CaO-Al_(2)O_(3)-based refining slags,leveraging machine learning to address data scarcity and improve prediction accuracy.An automated framework for algorithm integration,parameter tuning,and evaluation ranking framework(Auto-APE)is employed to develop customized data-driven models for various slag systems,including CaO-Al_(2)O_(3)-SiO_(2),CaO-Al_(2)O_(3)-CaF_(2),CaO-Al_(2)O_(3)-SiO_(2)-MgO,and CaO-Al_(2)O_(3)-SiO_(2)-MgO-CaF_(2).By incorporating optical basicity as a key feature,the models achieve an average validation error of 8.0%to 15.1%,significantly outperforming traditional empirical models.Additionally,symbolic regression is introduced to rapidly construct domain-specific features,such as optical basicity-like descriptors,offering a potential breakthrough in performance prediction for small datasets.This work highlights the critical role of domain-specific knowledge in understanding and predicting viscosity,providing a robust machine learning-based approach for optimizing refining slag properties.展开更多
In this article,we show the existence,uniqueness and stability of bounded solutions to the following quasilinear problems with mean curvature operator(φ'(x′(t)))′=f(t,x),t≥t_(0),lim_(t→∞)x(t)=ψ_(0),lim_(t→...In this article,we show the existence,uniqueness and stability of bounded solutions to the following quasilinear problems with mean curvature operator(φ'(x′(t)))′=f(t,x),t≥t_(0),lim_(t→∞)x(t)=ψ_(0),lim_(t→∞)x′(t)e^(t)=0,where t_(0) and ψ_(0) are real constants,φ(s)=s/√1−s^(2),s∈R with s∈(−1,1),f:[t_(0),∞)×R→R satisfies the Lipschitz or Osgood-type conditions.展开更多
Circumlunar abort trajectories constitute a vital contingency return strategy during the translunar phase of crewed lunar missions.This paper proposes a methodology for constructing the solution set of the circumlunar...Circumlunar abort trajectories constitute a vital contingency return strategy during the translunar phase of crewed lunar missions.This paper proposes a methodology for constructing the solution set of the circumlunar abort trajectory and leverages its advantageous properties to address the optimization design problem of abort trajectories.Initially,a solution set of all feasible abort trajectories,originating from an abort point on the nominal trajectory and complying with fundamental reentry constraints,is formulated through the introduction of two novel design parameters.Subsequently,the geometric characteristics of the solution set,as well as the distributional properties of key iterative constraint responses,including flight time and velocity increment,are analyzed.Finally,the characteristics exhibited in the solution set are employed to directly identify the design parameters of the abort trajectories with minimum flight time and velocity increment,thereby providing solutions to two distinct types of optimization problems.The simulation results for a variety of nominal trajectories,encompassing the reconstruction and redesign of the Apollo13 abort trajectory,validate the proposed method,demonstrating its ability to directly generate optimal abort trajectories.The method proposed in this paper investigates feasible abort trajectories from a global perspective,providing both a framework and convenience for mission planning and iterative optimization in abort trajectory design.展开更多
Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analyt...Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.展开更多
Substrate and nutrient supply are essential for vegetable cultivation in greenhouse.The strategies for plant nutrient supply vary depending on the cultivation methods or substrate dosages employed.With the development...Substrate and nutrient supply are essential for vegetable cultivation in greenhouse.The strategies for plant nutrient supply vary depending on the cultivation methods or substrate dosages employed.With the development of mechanization,wide-row spacing substrate cultivation became an optimize mode of the greenhouse cucumber cultivation,aligning with the trend of intelligent agriculture.To determine the optimal nutrient solution supply amount(NS)and supply frequency(SF)for promoting the integrated growth of cucumber under wide-row spacing substrate cultivation,we explored the effects of substrate supply amount(SS),NS,and SF on cucumber yield,quality,and element utilization efficiency.A five-level quadratic orthogonal rotation combination design with three experimental factors(NS,SF,and SS)was implemented for 23 coupling treatments over three growing seasons,including spring(2022S and 2023S)and autumn(2022A).The technique for order preference by similarity to ideal solution(TOPSIS)combining weights based on game theory was applied to construct cucumber comprehensive growth evaluation model.Single and two experimental factors analyses revealed significant effects of single factors and the coupling of NS-SS,NS-SF and SS-SF on the integrated growth of cucumber for all three growing seasons.For the NS-SF-SS combination,the optimal parameters for comprehensive cucumber growth were determined as follows:levels of^(-1).68 for NS,-0.7 for SF,and^(-1).682 for SS in 2022A;-0.43 for NS,-0.06 for SF,and 0.34 for SS in 2022S;0.3 for NS,-0.02 for SF,and 0.04 for SS in 2023S.Furthermore,for SS ranges of 2.00-3.01,3.01-4.50,4.50-5.99,5.99-7.00(L·plant^(-1)),the corresponding NS and SF intervals maximizing cucumber integrated growth in spring were:0.28-0.30(L·plant^(-1))and 6(times·d^(-1)),0.26-0.30(L·plant^(-1))and 6(times·d^(-1)),0.25-0.30(L·plant^(-1))and 6(times·d^(-1)),0.23-0.30(L·plant^(-1))and 6(times·d^(-1)),respectively.With the same SS,the corresponding NS and SF intervals that maximized cucumber integrated growth in autumn were:0.10(L·plant^(-1))and 8(times·d^(-1)),0.18(L·plant^(-1))and 7(times·d^(-1)),0.30(L·plant^(-1))and 6(times·d^(-1)),0.49(L·plant^(-1))and 5(times·d^(-1)),respectively.The results provide a theoretical basis for solution management,and further in-depth research on cucumber cultivation.展开更多
Doping in thin-film transistors(TFTs) plays a crucial role in tailoring material properties to enhance device performance, making them essential for advanced electronic applications. This study explores the synthesis ...Doping in thin-film transistors(TFTs) plays a crucial role in tailoring material properties to enhance device performance, making them essential for advanced electronic applications. This study explores the synthesis and characterization of TFTs fabricated using nickel(Ni)-doped indium oxide(In_(2)O_(3)) via a wet-chemical approach. The presented work investigates the effect of "Ni" incorporation in In_(2)O_(3) on the structural and electrical transport properties of In_(2)O_(3), revealing that higher "Ni" content decreases the oxygen vacancies, leading to a reduction in leakage current and a forward shift in threshold potential(V_(th)).Experimental findings reveal that Ni In O-based TFTs(with Ni = 0.5%) showcase enhanced electrical performance, achieving mobility of 7.54 cm^(2)/(V·s), an impressive ON/OFF current ratio of ~10^(7), a V_(th) of 6.26 V, reduced interfacial trap states(D_(it)) of 8.23 ×10^(12) cm^(-2) and enhanced biased stress stability. The efficacy of "Ni" incorporation is attributed to the upgraded Lewis acidity, stable Ni-O bond strength, and small ionic radius of Ni. Negative bias illumination stability(NBIS) measurements further indicate that device stability diminishes with shorter light wavelengths, likely due to the activation of oxygen vacancies. These findings validate the solution-processed techniques' potential for future large-scale, low-cost, energy-efficient, and high-performance electronics.展开更多
In-situ stress is a key parameter for underground mine design and rock stability analysis.The borehole overcoring technique is widely used for in-situ stress measurement,but the rheological recovery deformation of roc...In-situ stress is a key parameter for underground mine design and rock stability analysis.The borehole overcoring technique is widely used for in-situ stress measurement,but the rheological recovery deformation of rocks after stress relief introduces errors.To improve accuracy,this study proposes an in-situ stress solution theory that incorporates time-dependent stress relief effects.Triaxial stepwise loadingunloading rheological tests on granite and siltstone established quantitative relationships between instantaneous elastic recovery and viscoelastic recovery under different stress levels,confirming their impact on measurement accuracy.By integrating a dual-class elastic deformation recovery model,an improved in-situ stress solution theory was derived.Additionally,accounting for the nonlinear characteristics of rock masses,a determination method for time-dependent nonlinear mechanical parameters was proposed.Based on the CSIRO hollow inclusion strain cell,time-dependent strain correction equations and long-term confining pressure calibration equations were formulated.Finally,the proposed theory was successfully applied at one iron mine(736 m depth)in Xinjiang,China,and one coal mine(510 m depth)in Ningxia,China.Compared to classical theory,the calculated mean stress values showed accuracy improvements of 6.0%and 9.4%,respectively,validating the applicability and reliability of the proposed theory.展开更多
Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding str...Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.展开更多
Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fund...Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fundamental bases of this paper,are revealed.Based on these findings,an equivalent system is developed,which is a 2-body system with its total mass,constant angular momentum,kinetic and potential energies same as the total ones of three relative motions,so that it can be solved using the well-known theory of the 2-body system.From the solution of an equivalent system with the revealed characteristics of three relative motions,the general theoretical solutions of the 3-body system are obtained in the curve-integration forms along the orbits in the imaged radial motion space.The possible periodical orbits with generalised Kepler’s law are presented.Following the description and mathematical demonstrations of the proposed methods,the examples including Euler’s/Lagrange’s problems,and a reported numerical one are solved to validate the proposed methods.The methods derived from the 3-body system are extended to N-body problems.展开更多
Aim To prove the uniqueness of the viscosity solutions for the initial value problems of one type of second order parabolic partial differential equations: Methods Using comparison theorem. Results and Conclusion If u...Aim To prove the uniqueness of the viscosity solutions for the initial value problems of one type of second order parabolic partial differential equations: Methods Using comparison theorem. Results and Conclusion If u0 is uniform continuousfunction in RN , F is continuous function in RNx(N) and F is degenerate elliptic, then thisequation has the sole viscosity solution.展开更多
This study is focused on the viscosity behavior of the aqueous solution of the CMC prepared in a two phase medium C 6H 6 C 2H 5OH H 2O.The effects of properties such as the degree o...This study is focused on the viscosity behavior of the aqueous solution of the CMC prepared in a two phase medium C 6H 6 C 2H 5OH H 2O.The effects of properties such as the degree of substitution,molecular weight,distribution of substituent along the molecular chain or at positions C 2,C 3 and C 6 on viscosity are investigated respectively.The difference of the CMC synthesized in medium benzene ethanol and ethanol is studied.The addition of benzene is beneficial to improve the viscosity and stability of CMC solutions.The CMC with homogeneous distribution of substituent along the chain and the high substitution at position C 6 possess a good compatibility with organic acids and excellent resistance to alkali,salts and acid.展开更多
A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics （MD） simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl soluti...A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics （MD） simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl solutions confined in the nanochannel. The simulation is performed under different moving speeds of the upper wall, different heights and different surface charge densities in the nanochannel. The simulation results indicate that with the increase in the surface charge density and the decrease in the nanochannel height and the shear rate, the vibration effect of silicon atoms on the shear viscosity of the confined fluid in the nanochannel cannot be ignored. Compared with still silicon atoms, the vibrating silicon atoms result in the decrease in the viscosity when the height of the nanochannel is less than 0.8 nm and the shear rate is less than 1.0 ×10^11 s^-1, and the effect of the vibrating silicon atoms on the shear viscosity is significant when the shear rate is small. This is due to the fact that the vibrating silicon atoms weaken the interactions between the counter-ions （Na^＋ ） and the charged surface.展开更多
The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association...The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association constant is defined as the molar association constant divided by the molar mass of individual polymer chain and is numerically interconvertible with the Huggins coefficient. The molar association constant is directly proportional to the effective hydrodynamic volume of the polymer chain in solution and is irrespective of the chain architecture. The effective hydrodynamic volume accounts for the non-spherical conformation of a short polymer chain in solution and is a product of a shape factor and hydrodynamic volume. The observed enhancement of Huggins coefficient for short chain and branched polymer is satisfactorily interpreted by the concept of self-association. The concept of self-association allows us to predict the existence of a boundary concentration C-s(dynamic contact concentration) which divides the dilute polymer solution into two regions.展开更多
In this paper, we consider the global existence of classical solution to the 3-D compressible Navier-Stokes equations with a density-dependent viscosity coefficient λ(ρ)provided that the initial energy is small in s...In this paper, we consider the global existence of classical solution to the 3-D compressible Navier-Stokes equations with a density-dependent viscosity coefficient λ(ρ)provided that the initial energy is small in some sense. In our result, we give a relation between the initial energy and the viscosity coefficient μ, and it shows that the initial energy can be large if the coefficient of the viscosity μ is taken to be large, which implies that large viscosity μ means large solution.展开更多
Careful measurements of the dilute solution viscosities of polyethylene glycol and polyvinyl alcohol in water were carried out. The reduced viscosities of both polymer solutions plot upward curves at extremely dilute ...Careful measurements of the dilute solution viscosities of polyethylene glycol and polyvinyl alcohol in water were carried out. The reduced viscosities of both polymer solutions plot upward curves at extremely dilute concentration levels similar to the phenomena observed for many polymer solutions in the early 1950's. Upon observation of the changes of the flow times of pure water in and the wall surface wettability of the viscometer after measuring solution viscosity, a view was formed that the observed viscosity abnormality at extremely dilute concentration regions is solely due to the effect of adsorption of polymer chains onto the wall surface of viscometer. A theory of adsorption effect based on the Langmuir isotherms was proposed and a mathematical; analysis for data treatment was performed. The theory could adequately describe the existing viscosity data. It seems necessary to correct the viscosity result of dilute polymer solutions measured by glass capillary viscometer by taking into account the effect of adsorption in all cases.展开更多
Molecular dynamics （MD） method is adopted to simulate the conformation variations of konjac glucomannan （KGM） saline solution at different temperatures, and structurally analyze the trends and reasons of viscosity...Molecular dynamics （MD） method is adopted to simulate the conformation variations of konjac glucomannan （KGM） saline solution at different temperatures, and structurally analyze the trends and reasons of viscosity change in KGM saline solution with temperature. The experimental results have been analyzed to find out that the sum of formative hydrogen bonds decreases with the rise of temperature and the amount of intramolecular hydrogen bonds suddenly increases at 323 K. Besides, in terms of molecular orbital data obtained from simulation, we can know that hydrogen bonding energy also decreases with the rise of temperature. Therefore, we can predict the viscosity of KGM saline solution decreases gradually when rising the temperature.展开更多
In this work, we obtain the global existence and uniqueness of classical solu-tions to a viscous liquid-gas two-phase model with mass-dependent viscosity and vacuum in one dimension, where the initial vacuum is allowe...In this work, we obtain the global existence and uniqueness of classical solu-tions to a viscous liquid-gas two-phase model with mass-dependent viscosity and vacuum in one dimension, where the initial vacuum is allowed. We get the upper and lower bounds of gas and liquid masses n and m by the continuity methods which we use to study the compressible Navier-Stokes equations.展开更多
基金financially supported by the Russian Science Foundation(No.20-13-00038).
文摘Poly(1-butyl-3-vinylimidazolium bromide)is a polymerized ionic liquid(PILs),a relatively new class of materials that combines the attractive properties of ionic liquids(ILs)and polyelectrolytes and finds wide applications.The backbone of this PIL is composed of quaternary imidazolium salts,which are among the most promising and popular ILs.However,little is known about the physicochemical characteristics of the aqueous solutions of this PIL.In this study,we synthesized and characterized samples of this PIL and obtained experimental data on the viscosity,static and dynamic light scattering,and nuclear magnetic resonance diffusometry for aqueous and aqueous KBr solutions with varying polymer contents at T=298.15 K.We discuss the effects of the polymer concentration and salinity on the behavior of the solution.
基金Supported by the Doctoral Research Start-up Project of Yuncheng University(YQ-2023067)Project of Shanxi Natural Science Foundation(202303021211189)+1 种基金Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Provinces(20220036)Shanxi ProvinceIntelligent Optoelectronic Sensing Application Technology Innovation Center and Shanxi Province Optoelectronic Information Science and TechnologyLaboratory,Yuncheng University.
文摘In this study,a straightforward one-step hydrothermal method was successfully utilized to synthesize the solid solution Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)-Na_(2)Ni_(2)Ti_(6)O_(16)(NNMTO-x),where x denotes the molar percentage of Na_(2)Ni_(2)Ti_(6)O_(16)(NNTO)within Na_(0.9)Mg_(0.45)Ti_(3.55)O_(8)(NMTO),with x values of 10,20,30,40,and 50.Both XPS(X-ray Photoelectron Spectroscopy)and EDX(Energy Dispersive X-ray Spectroscopy)analyses unequivocally validated the formation of the NNMTO-x solid solutions.It was observed that when x is below 40,the NNMTO-x solid solution retains the structural characteristics of the original NMTO.However,beyond this threshold,significant alterations in crystal morphology were noted,accompanied by a noticeable decline in photocatalytic activity.Notably,the absorption edge of NNMTO-x(x<40)exhibited a shift towards the visible-light spectrum,thereby substantially broadening the absorption range.The findings highlight that NNMTO-30 possesses the most pronounced photocatalytic activity for the reduction of CO_(2).Specifically,after a 6 h irradiation period,the production rates of CO and CH_(4)were recorded at 42.38 and 1.47μmol/g,respectively.This investigation provides pivotal insights that are instrumental in the advancement of highly efficient and stable photocatalysts tailored for CO_(2)reduction processes.
基金supported by the National Key Research and Development Program of China(No.2023YFB3712401),the National Natural Science Foundation of China(No.52274301)the Aeronautical Science Foundation of China(No.2023Z0530S6005)the Ningbo Yongjiang Talent-Introduction Programme(No.2022A-023-C).
文摘The viscosity of refining slags plays a critical role in metallurgical processes.However,obtaining accurate viscosity data remains challenging due to the complexities of high-temperature experiments,often relying on empirical models with limited predictive capabilities.This study focuses on the influence of optical basicity on viscosity in CaO-Al_(2)O_(3)-based refining slags,leveraging machine learning to address data scarcity and improve prediction accuracy.An automated framework for algorithm integration,parameter tuning,and evaluation ranking framework(Auto-APE)is employed to develop customized data-driven models for various slag systems,including CaO-Al_(2)O_(3)-SiO_(2),CaO-Al_(2)O_(3)-CaF_(2),CaO-Al_(2)O_(3)-SiO_(2)-MgO,and CaO-Al_(2)O_(3)-SiO_(2)-MgO-CaF_(2).By incorporating optical basicity as a key feature,the models achieve an average validation error of 8.0%to 15.1%,significantly outperforming traditional empirical models.Additionally,symbolic regression is introduced to rapidly construct domain-specific features,such as optical basicity-like descriptors,offering a potential breakthrough in performance prediction for small datasets.This work highlights the critical role of domain-specific knowledge in understanding and predicting viscosity,providing a robust machine learning-based approach for optimizing refining slag properties.
基金Supported by the National Natural Science Foundation of China(Grant Nos.12361040,12061064)the National Science Foundation of Gansu Province(Grant No.22JR5RA264)State Scholarship Fund(Grant No.20230862021).
文摘In this article,we show the existence,uniqueness and stability of bounded solutions to the following quasilinear problems with mean curvature operator(φ'(x′(t)))′=f(t,x),t≥t_(0),lim_(t→∞)x(t)=ψ_(0),lim_(t→∞)x′(t)e^(t)=0,where t_(0) and ψ_(0) are real constants,φ(s)=s/√1−s^(2),s∈R with s∈(−1,1),f:[t_(0),∞)×R→R satisfies the Lipschitz or Osgood-type conditions.
文摘Circumlunar abort trajectories constitute a vital contingency return strategy during the translunar phase of crewed lunar missions.This paper proposes a methodology for constructing the solution set of the circumlunar abort trajectory and leverages its advantageous properties to address the optimization design problem of abort trajectories.Initially,a solution set of all feasible abort trajectories,originating from an abort point on the nominal trajectory and complying with fundamental reentry constraints,is formulated through the introduction of two novel design parameters.Subsequently,the geometric characteristics of the solution set,as well as the distributional properties of key iterative constraint responses,including flight time and velocity increment,are analyzed.Finally,the characteristics exhibited in the solution set are employed to directly identify the design parameters of the abort trajectories with minimum flight time and velocity increment,thereby providing solutions to two distinct types of optimization problems.The simulation results for a variety of nominal trajectories,encompassing the reconstruction and redesign of the Apollo13 abort trajectory,validate the proposed method,demonstrating its ability to directly generate optimal abort trajectories.The method proposed in this paper investigates feasible abort trajectories from a global perspective,providing both a framework and convenience for mission planning and iterative optimization in abort trajectory design.
基金supported by the National Natural Science Foundation of China(No.41941018)Shanghai Gaofeng Discipline Construction Funding.
文摘Strong seismic excitation and fault dislocation are likely to occur simultaneously in high-intensity seismic zones,causing severe damage to tunnels crossing active fault zones.This paper aims to develop a novel analytical solution to determine the longitudinal mechanical responses of tunnels subjected to the combined effects of seismic waves and strike-slip faulting.Adopting the elastic springbeam model,the seismic waves are modelled as shear horizontal(SH)waves and the fault dislocation follows an S-shaped pattern;the superposition principle for free-fielddisplacements caused by both effects is assumed.In addition,the transmission and reflectionof seismic waves at the fault-rock geological interface and the tangential contact conditions at the tunnel-rock interface are considered.The analytical model is validated against numerical simulations,confirmingits accuracy in calculating tunnel responses.Moreover,a parametric study is conducted to evaluate the impact of key factors,including fault displacement,fault zone width,fault dip angle,earthquake frequency,rock conditions,tunnel lining stiffness,and tangential contact conditions,on tunnel responses.Compared with each effect alone,the combined effects of seismic waves and strike-slip faulting significantlychange the tunnel deformation and internal forces,leading to increased tunnel responses,especially within the fault zone and near the fault-rock interfaces.Depending on specificparameters,tunnel responses can be classifiedinto seismic-dominated,faulting-dominated,and seismic-faulting coupled responses on the basis of the relative contributions of each effect.The proposed analytical solution can be applied to quickly predict the longitudinal mechanical behaviour of tunnels under such combined effects in engineering applications.
基金supported by the China Agriculture Research System(Grant No.CARS-23-D06)the Key Research and Development Program of Shaanxi Province(Grant Nos.2024NC2-GJHX-29 and 2024NC-ZDCYL-05-08)Shaanxi Agricultural Collaborative Innovation and Extension Alliance Project(Grant No.LMZD202202).
文摘Substrate and nutrient supply are essential for vegetable cultivation in greenhouse.The strategies for plant nutrient supply vary depending on the cultivation methods or substrate dosages employed.With the development of mechanization,wide-row spacing substrate cultivation became an optimize mode of the greenhouse cucumber cultivation,aligning with the trend of intelligent agriculture.To determine the optimal nutrient solution supply amount(NS)and supply frequency(SF)for promoting the integrated growth of cucumber under wide-row spacing substrate cultivation,we explored the effects of substrate supply amount(SS),NS,and SF on cucumber yield,quality,and element utilization efficiency.A five-level quadratic orthogonal rotation combination design with three experimental factors(NS,SF,and SS)was implemented for 23 coupling treatments over three growing seasons,including spring(2022S and 2023S)and autumn(2022A).The technique for order preference by similarity to ideal solution(TOPSIS)combining weights based on game theory was applied to construct cucumber comprehensive growth evaluation model.Single and two experimental factors analyses revealed significant effects of single factors and the coupling of NS-SS,NS-SF and SS-SF on the integrated growth of cucumber for all three growing seasons.For the NS-SF-SS combination,the optimal parameters for comprehensive cucumber growth were determined as follows:levels of^(-1).68 for NS,-0.7 for SF,and^(-1).682 for SS in 2022A;-0.43 for NS,-0.06 for SF,and 0.34 for SS in 2022S;0.3 for NS,-0.02 for SF,and 0.04 for SS in 2023S.Furthermore,for SS ranges of 2.00-3.01,3.01-4.50,4.50-5.99,5.99-7.00(L·plant^(-1)),the corresponding NS and SF intervals maximizing cucumber integrated growth in spring were:0.28-0.30(L·plant^(-1))and 6(times·d^(-1)),0.26-0.30(L·plant^(-1))and 6(times·d^(-1)),0.25-0.30(L·plant^(-1))and 6(times·d^(-1)),0.23-0.30(L·plant^(-1))and 6(times·d^(-1)),respectively.With the same SS,the corresponding NS and SF intervals that maximized cucumber integrated growth in autumn were:0.10(L·plant^(-1))and 8(times·d^(-1)),0.18(L·plant^(-1))and 7(times·d^(-1)),0.30(L·plant^(-1))and 6(times·d^(-1)),0.49(L·plant^(-1))and 5(times·d^(-1)),respectively.The results provide a theoretical basis for solution management,and further in-depth research on cucumber cultivation.
基金funded by the research startup funding of National Research Foundation (NRF) of Korea through the Ministry of Science and ICT 2022R1G1A1009887Part of this study was supported by research start-up funding of Anhui University (S202418001/078)。
文摘Doping in thin-film transistors(TFTs) plays a crucial role in tailoring material properties to enhance device performance, making them essential for advanced electronic applications. This study explores the synthesis and characterization of TFTs fabricated using nickel(Ni)-doped indium oxide(In_(2)O_(3)) via a wet-chemical approach. The presented work investigates the effect of "Ni" incorporation in In_(2)O_(3) on the structural and electrical transport properties of In_(2)O_(3), revealing that higher "Ni" content decreases the oxygen vacancies, leading to a reduction in leakage current and a forward shift in threshold potential(V_(th)).Experimental findings reveal that Ni In O-based TFTs(with Ni = 0.5%) showcase enhanced electrical performance, achieving mobility of 7.54 cm^(2)/(V·s), an impressive ON/OFF current ratio of ~10^(7), a V_(th) of 6.26 V, reduced interfacial trap states(D_(it)) of 8.23 ×10^(12) cm^(-2) and enhanced biased stress stability. The efficacy of "Ni" incorporation is attributed to the upgraded Lewis acidity, stable Ni-O bond strength, and small ionic radius of Ni. Negative bias illumination stability(NBIS) measurements further indicate that device stability diminishes with shorter light wavelengths, likely due to the activation of oxygen vacancies. These findings validate the solution-processed techniques' potential for future large-scale, low-cost, energy-efficient, and high-performance electronics.
基金supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2024ZD1700201)the National Natural Science Foundation of China(Nos.U2034206,51974014 and 51574014)+1 种基金the Guangdong Basic and Applied Basic Research Foundation(No.2024A1515011631)the National Key Research and Development Project of China(No.2022YFC3004601)。
文摘In-situ stress is a key parameter for underground mine design and rock stability analysis.The borehole overcoring technique is widely used for in-situ stress measurement,but the rheological recovery deformation of rocks after stress relief introduces errors.To improve accuracy,this study proposes an in-situ stress solution theory that incorporates time-dependent stress relief effects.Triaxial stepwise loadingunloading rheological tests on granite and siltstone established quantitative relationships between instantaneous elastic recovery and viscoelastic recovery under different stress levels,confirming their impact on measurement accuracy.By integrating a dual-class elastic deformation recovery model,an improved in-situ stress solution theory was derived.Additionally,accounting for the nonlinear characteristics of rock masses,a determination method for time-dependent nonlinear mechanical parameters was proposed.Based on the CSIRO hollow inclusion strain cell,time-dependent strain correction equations and long-term confining pressure calibration equations were formulated.Finally,the proposed theory was successfully applied at one iron mine(736 m depth)in Xinjiang,China,and one coal mine(510 m depth)in Ningxia,China.Compared to classical theory,the calculated mean stress values showed accuracy improvements of 6.0%and 9.4%,respectively,validating the applicability and reliability of the proposed theory.
基金supported by the National Key R&D Program of China(2023YFA1406200)the National Natural Science Foundation of China(T2521005,12174144,12474009,12174146,and 124B2059)the Special Construction Project Fund for Shan-dong Province Taishan Scholars.
文摘Multifunctional optical responsive materials have grown increasingly pivotal in addressingthe escalating demands of sensing,detection,and anti-counterfeiting applications[1,2].These materials exhibit distinct visible optical variations upon exposure to external stimuli,such as pressure,temperature,light,solvents,pH fluctuations,or mechanical force.Fluorescent sensing and anti-counterfeiting technologies leveraging these optical responses have emerged as highly promising solutions.
基金supported by the National Key R&D Program of China (No. 2018YFA0707300)the National Natural Science Foundation of China (No. 52374376)the Introduction Plan for High end Foreign Experts, China (No. G2023105001L)。
文摘Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.
文摘Generalised reduced masses with a set of equations governing the three relative motions between two of 3-bodies in their gravitational field are established,of which the dynamic characteristics of 3-body dynamics,fundamental bases of this paper,are revealed.Based on these findings,an equivalent system is developed,which is a 2-body system with its total mass,constant angular momentum,kinetic and potential energies same as the total ones of three relative motions,so that it can be solved using the well-known theory of the 2-body system.From the solution of an equivalent system with the revealed characteristics of three relative motions,the general theoretical solutions of the 3-body system are obtained in the curve-integration forms along the orbits in the imaged radial motion space.The possible periodical orbits with generalised Kepler’s law are presented.Following the description and mathematical demonstrations of the proposed methods,the examples including Euler’s/Lagrange’s problems,and a reported numerical one are solved to validate the proposed methods.The methods derived from the 3-body system are extended to N-body problems.
文摘Aim To prove the uniqueness of the viscosity solutions for the initial value problems of one type of second order parabolic partial differential equations: Methods Using comparison theorem. Results and Conclusion If u0 is uniform continuousfunction in RN , F is continuous function in RNx(N) and F is degenerate elliptic, then thisequation has the sole viscosity solution.
文摘This study is focused on the viscosity behavior of the aqueous solution of the CMC prepared in a two phase medium C 6H 6 C 2H 5OH H 2O.The effects of properties such as the degree of substitution,molecular weight,distribution of substituent along the molecular chain or at positions C 2,C 3 and C 6 on viscosity are investigated respectively.The difference of the CMC synthesized in medium benzene ethanol and ethanol is studied.The addition of benzene is beneficial to improve the viscosity and stability of CMC solutions.The CMC with homogeneous distribution of substituent along the chain and the high substitution at position C 6 possess a good compatibility with organic acids and excellent resistance to alkali,salts and acid.
基金The National Basic Research Program of China ( 973Program) ( No. 2006CB300404)the National Natural Science Foundationof China ( No. 50875047, 50676019)the Natural Science Foundation ofJiangsu Province ( No. BK2006510, BK2008201)
文摘A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics （MD） simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl solutions confined in the nanochannel. The simulation is performed under different moving speeds of the upper wall, different heights and different surface charge densities in the nanochannel. The simulation results indicate that with the increase in the surface charge density and the decrease in the nanochannel height and the shear rate, the vibration effect of silicon atoms on the shear viscosity of the confined fluid in the nanochannel cannot be ignored. Compared with still silicon atoms, the vibrating silicon atoms result in the decrease in the viscosity when the height of the nanochannel is less than 0.8 nm and the shear rate is less than 1.0 ×10^11 s^-1, and the effect of the vibrating silicon atoms on the shear viscosity is significant when the shear rate is small. This is due to the fact that the vibrating silicon atoms weaken the interactions between the counter-ions （Na^＋ ） and the charged surface.
基金This work was supported by the Chinese National Basic Research Project "Macromolecular Condensed State" and National Natural Science Foundation of China
文摘The concentration dependence of the reduced viscosity of dilute polymer solution is interpreted in the light of a new concept of the self-association of polymer chains in dilute solution. The apparent self-association constant is defined as the molar association constant divided by the molar mass of individual polymer chain and is numerically interconvertible with the Huggins coefficient. The molar association constant is directly proportional to the effective hydrodynamic volume of the polymer chain in solution and is irrespective of the chain architecture. The effective hydrodynamic volume accounts for the non-spherical conformation of a short polymer chain in solution and is a product of a shape factor and hydrodynamic volume. The observed enhancement of Huggins coefficient for short chain and branched polymer is satisfactorily interpreted by the concept of self-association. The concept of self-association allows us to predict the existence of a boundary concentration C-s(dynamic contact concentration) which divides the dilute polymer solution into two regions.
文摘In this paper, we consider the global existence of classical solution to the 3-D compressible Navier-Stokes equations with a density-dependent viscosity coefficient λ(ρ)provided that the initial energy is small in some sense. In our result, we give a relation between the initial energy and the viscosity coefficient μ, and it shows that the initial energy can be large if the coefficient of the viscosity μ is taken to be large, which implies that large viscosity μ means large solution.
基金This work was supported by the National Basic Research Project-Macromolecular Condensed State,and the National Natural Science Foundationof China
文摘Careful measurements of the dilute solution viscosities of polyethylene glycol and polyvinyl alcohol in water were carried out. The reduced viscosities of both polymer solutions plot upward curves at extremely dilute concentration levels similar to the phenomena observed for many polymer solutions in the early 1950's. Upon observation of the changes of the flow times of pure water in and the wall surface wettability of the viscometer after measuring solution viscosity, a view was formed that the observed viscosity abnormality at extremely dilute concentration regions is solely due to the effect of adsorption of polymer chains onto the wall surface of viscometer. A theory of adsorption effect based on the Langmuir isotherms was proposed and a mathematical; analysis for data treatment was performed. The theory could adequately describe the existing viscosity data. It seems necessary to correct the viscosity result of dilute polymer solutions measured by glass capillary viscometer by taking into account the effect of adsorption in all cases.
基金Supported by the National Natural Science Foundation of China (30371009)Science Foundation of Fujian Department of Education (JA03059)Key Project of Science and Technology of Fujian Province (2003Y008)
文摘Molecular dynamics （MD） method is adopted to simulate the conformation variations of konjac glucomannan （KGM） saline solution at different temperatures, and structurally analyze the trends and reasons of viscosity change in KGM saline solution with temperature. The experimental results have been analyzed to find out that the sum of formative hydrogen bonds decreases with the rise of temperature and the amount of intramolecular hydrogen bonds suddenly increases at 323 K. Besides, in terms of molecular orbital data obtained from simulation, we can know that hydrogen bonding energy also decreases with the rise of temperature. Therefore, we can predict the viscosity of KGM saline solution decreases gradually when rising the temperature.
基金Supported by the National Natural Science Foundation of China(11171340)
文摘In this work, we obtain the global existence and uniqueness of classical solu-tions to a viscous liquid-gas two-phase model with mass-dependent viscosity and vacuum in one dimension, where the initial vacuum is allowed. We get the upper and lower bounds of gas and liquid masses n and m by the continuity methods which we use to study the compressible Navier-Stokes equations.
