Aim To research the computer optimization design in material formulation. Methods The professional software including experimental design, mathematical modeling and optimization of single and multiple purposes was d...Aim To research the computer optimization design in material formulation. Methods The professional software including experimental design, mathematical modeling and optimization of single and multiple purposes was developed and applied to the formulation design for the flame retardant ethylenepropylene-diene mischpolymer (EPDM) insulation composites. With the aid of equipartition design, the mathematical models were established based on the optimization of the four properties (limiting oxygen index, volume resistance, tensile strength and elongation). Results The models from limited experiments had good significance, and the modeling analysis conclusions were in good agreement with later experiments. The optimization formulation was practically excellent. Conclusion The software enables practically a comprehensive multi-purpose use of material formulation research.展开更多
In this article, a reduced mixed finite element （MFE） formulation based on proper orthogonal decomposition （POD） for the non-stationary conduction-convection problems is presented. Also the error estimates between...In this article, a reduced mixed finite element （MFE） formulation based on proper orthogonal decomposition （POD） for the non-stationary conduction-convection problems is presented. Also the error estimates between the reduced MFE solutions based on POD and usual MFE solutions are derived. It is shown by numerical examples that the results of numerical computation are consistent with theoretical conclusions. Moreover, it is shown that the reduced MFE formulation based on POD is feasible and efficient in finding numerical solutions for the non-stationary conduction-convection problems.展开更多
A proper orthogonal decomposition（POD） method was successfully used in the reduced-order modeling of complex systems.In this paper,we extend the applications of POD method,namely,apply POD method to a classical fini...A proper orthogonal decomposition（POD） method was successfully used in the reduced-order modeling of complex systems.In this paper,we extend the applications of POD method,namely,apply POD method to a classical finite element（FE） formulation for second-order hyperbolic equations with real practical applied background,establish a reduced FE formulation with lower dimensions and high enough accuracy,and provide the error estimates between the reduced FE solutions and the classical FE solutions and the implementation of algorithm for solving reduced FE formulation so as to provide scientific theoretic basis for service applications.Some numerical examples illustrate the fact that the results of numerical computation are consistent with theoretical conclusions.Moreover,it is shown that the reduced FE formulation based on POD method is feasible and efficient for solving FE formulation for second-order hyperbolic equations.展开更多
In this paper, we extend the applications of proper orthogonal decomposition （POD） method, i.e., apply POD method to a mixed finite element （MFE） formulation naturally satisfied Brezz-Babu^ka for parabolic equatio...In this paper, we extend the applications of proper orthogonal decomposition （POD） method, i.e., apply POD method to a mixed finite element （MFE） formulation naturally satisfied Brezz-Babu^ka for parabolic equations, establish a reduced-order MFE formulation with lower dimensions and sufficiently high accuracy, and provide the error estimates between the reduced-order POD MFE solutions and the classical MFE solutions and the implementation of algorithm for solving reduced-order MFE formulation. Some numerical examples illustrate the fact that the results of numerical computation are consis- tent with theoretical conclusions. Moreover, it is shown that the new reduced-order MFE formulation based on POD method is feasible and efficient for solving MFE formulation for parabolic equations.展开更多
The Birkhoffian mechanics is more general than the Hamilton mechanics,but only some dynamical systems can be realized as a Birkhoffian formulation.This paper proposes a novel Birkhoffian formulation for the classical ...The Birkhoffian mechanics is more general than the Hamilton mechanics,but only some dynamical systems can be realized as a Birkhoffian formulation.This paper proposes a novel Birkhoffian formulation for the classical Bessel equation.Based on the first method of Santilli,the Birkhoffian formulation of Bessel equation is established under the assumption that the Birkhoffian describes the total physical energy of the corresponding conservative systems.Zero and n-th order classical Bessel equations are studied to verify the effectiveness of the proposed formulation.展开更多
In this paper the effect of gasoline formulations on fuel economy and emissions were studied,aiming at exploring the optimized fuel formulation that can alleviate energy crisis and greenhouse effect to some extent.Fiv...In this paper the effect of gasoline formulations on fuel economy and emissions were studied,aiming at exploring the optimized fuel formulation that can alleviate energy crisis and greenhouse effect to some extent.Five gasoline blends with same research octane number(RON)were designed and tested on a calibrated gasoline direct injection(GDI)engine under the mapped characteristic conditions.Test results illustrate that the optimized fuel formulation shows good superiority in fuel economy,and reduces carbon dioxide(CO2)emissions at low engine speeds with medium loads.The brake-specific fuel consumption(BSFC)decreased by a maximum value of 3.26%mainly because of the improvement of combustion velocity and the optimization of low heating value.The optimized fuel formulation simultaneously increases total hydrocarbon(THC)emissions.Nevertheless,it also markedly reduces CO2 emissions,reaching the maximum value of 2.34%.The research results can be applied practically by refineries to reduce the CO2 emissions and to alleviate the greenhouse effect.展开更多
In this paper, a new variational formulation for a reaction-diffusion problem in broken Sobolev space is proposed. And the new formulation in the broken Sobolev space will be proved that it is well-posed and equivalen...In this paper, a new variational formulation for a reaction-diffusion problem in broken Sobolev space is proposed. And the new formulation in the broken Sobolev space will be proved that it is well-posed and equivalent to the standard Galerkin variational formulation. The method will be helpful to easily solve the original partial differential equation numerically. And the method is novel and interesting, which can be used to deal with some complicated problem, such as the low regularity problem, the differential-integral problem and so on.展开更多
The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant h...The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant health, such as growth promotion, systemic resistance induction and fertility improvements. Some strains are powerful antibiotic producers, and their suitability for use in biocontrol systems must be carefully assessed. However, many other active strains have no antibiotic capacity, and these are likely to be more useful in food production systems since they have not adverse effects on important groups of beneficial soil organisms. We have assessed the performance of selected naturally occurring Trichoderma strains (singly and in combination) and developed TUSAL, a mixture of Trichoderma harzianum and T. viride that has demonstrated to be effective against major pathogens in sugar beet and horticulture. TUSAL, has been bulked up and tested under field conditions, showing positive effects on precocity and root development, and increasing the crop production in field trials carried out in different pathosystems. The environmental impact of TUSAL strains on beneficial organisms in the environment were assessed before release, and molecular detection methods were developed to monitor the presence and performance of strains in the field. In addition, Trichoderma protein extracts with high glucanase and chitinase activities, have also been obtained from wild type strains and their effectiveness as biofungicides was tested in laboratory and field conditions, defining the concentration of protein necessary to produce fungicide effects. The genes coding for protein production were introduced into suitable organisms for large-scale production in the laboratory, never released to the environment. The effect of these novel biofungicide proteins was studied separately and synergistically with Trichoderma conidia, and with minimal doses of chemical fungicides. Suitable active Trichoderma strains are being registered in the EU by the company NBT. Both Trichoderma strains and proteins are included in formulations patented as biocontrol agents.展开更多
The taut mooring system using synthetic fiber ropes has overcome the shortcomings such as the large self-weight of the mooring lines and provides better mooring performance for the floating structures.The polyester ro...The taut mooring system using synthetic fiber ropes has overcome the shortcomings such as the large self-weight of the mooring lines and provides better mooring performance for the floating structures.The polyester rope has attracted much attention among numerous synthetic fiber rope materials due to its lightweight,low price,corrosion resistance,and high strength.Thus,the mooring characteristics of it are worth studying.Polyester mooring lines are flexible in deep water,when a marine structure is moored by them,the geometric nonlinearity such as large displacement,large stretch,and large bending deformation,and the material nonlinearity like viscoelastic of the polyester ropes become complex integrated problems to be studied.Considering the nonlinear phenomenon,the simulation and calculation of a polyester line were carried out by the absolute nodal coordinate formulation(ANCF)in this paper since the ANCF method has advantages in dealing with the significant deformation problems of the flexible structures.In addition,a chain mooring line was also simulated for comparison,and the results show that the polyester ropes reduce the self-weight of the mooring lines and provide sufficient mooring strength at the same time,and the nonlinear phenomenon of the polyester ropes is different from that of the chain mooring lines.展开更多
Many methods have been proposed in the literature for solving the split variational inequality problem.Most of these methods either require that this problem is transformed into an equivalent variational inequality pr...Many methods have been proposed in the literature for solving the split variational inequality problem.Most of these methods either require that this problem is transformed into an equivalent variational inequality problem in a product space,or that the underlying operators are co-coercive.However,it has been discovered that such product space transformation may cause some potential difficulties during implementation and its approach may not fully exploit the attractive splitting nature of the split variational inequality problem.On the other hand,the co-coercive assumption of the underlying operators would preclude the potential applications of these methods.To avoid these setbacks,we propose two new relaxed inertial methods for solving the split variational inequality problem without any product space transformation,and for which the underlying operators are freed from the restrictive co-coercive assumption.The methods proposed,involve projections onto half-spaces only,and originate from an explicit discretization of a dynamical system,which combines both the inertial and relaxation techniques in order to achieve high convergence speed.Moreover,the sequence generated by these methods is shown to converge strongly to a minimum-norm solution of the problem in real Hilbert spaces.Furthermore,numerical implementations and comparisons are given to support our theoretical findings.展开更多
This work presents the design of a robust foam formulation that tolerates harsh reservoir conditions(high salinity,high divalent ion concentration,high temperature,light oil,and hydrocarbon injection gas)in a sandston...This work presents the design of a robust foam formulation that tolerates harsh reservoir conditions(high salinity,high divalent ion concentration,high temperature,light oil,and hydrocarbon injection gas)in a sandstone reservoir.For this,we selected anionic Alpha Olefin Sulfonate(AOS)surfactants and studied their synergistic effects in mixtures with zwitterionic betaines to enhance foam performance.The laboratory workflow used to define the best formulation followed a de-risking approach in three consecutive phases.First,(phase 1)the main surfactant(AOS)was selected among a series of commercial candidates in static conditions.Then,(phase 2)the betaine booster to be combined with the previously selected AOS was chosen and their ratio optimized in static conditions.Subsequently,(phase 3)the surfactant/booster ratio was optimized under dynamic conditions in a porous medium in the absence and the presence of oil.As a result of this study,a mixture of an AOS C14-C16 and cocamidopropyl hydroxysultaine(CAPHS)was selected as the one having the best performance.The designed formulation was proven to be robust in a wide range of conditions.It generated a strong and stable foam at reservoir conditions,overcoming variations in salinity and foam quality,and tolerated the presence of oil.展开更多
^(14)C-butachlor and ^(14)C-oxadiazon could be released from four kinds of CR formulations into water respectively, and the release percentage of each herbicide increased with time, which could be expressed by regress...^(14)C-butachlor and ^(14)C-oxadiazon could be released from four kinds of CR formulations into water respectively, and the release percentage of each herbicide increased with time, which could be expressed by regression equations (very obvious positive relationship). The release percentages of ^(14)C-herbicides from CR formulations were related to herbicide CR formulation and water type. Total recovery including ^(14)C-released and ^(14)C-left in formulations for each ^(14)C-herbicide was high at the 56th day after treatment. Some of the released ^(14)C-butachlor in water could be hydrolysed although under dark condition. The rate of hydrolysis was influenced by water type and formulations.展开更多
In this article, the author uses the compensated compactness method coupled with some basic ideas of the kinetic formulation developed by Lions, Perthame, Souganidis and Tadmor to give a refined proof for the existenc...In this article, the author uses the compensated compactness method coupled with some basic ideas of the kinetic formulation developed by Lions, Perthame, Souganidis and Tadmor to give a refined proof for the existence of global entropy solutions to a system of quadratic flux. The fire-new method of reduction of Young measures is a pith of this work.展开更多
A time semi-discrete Crank-Nicolson （CN） formulation with second-order time accuracy for the non-stationary parabolized Navier-Stokes equations is firstly established. And then, a fully discrete stabilized CN mixed ...A time semi-discrete Crank-Nicolson （CN） formulation with second-order time accuracy for the non-stationary parabolized Navier-Stokes equations is firstly established. And then, a fully discrete stabilized CN mixed finite volume element （SCNMFVE） formu- lation based on two local Gaussian integrals and parameter-free with the second-order time accuracy is established directly from the time semi-discrete CN formulation so that it could avoid the discussion for semi-discrete SCNMFVE formulation with respect to spatial wriables and its theoretical analysis becomes very simple. Finally, the error estimates of SCNMFVE solutions are provided.展开更多
In this study, we employ mixed finite element （MFE） method, two local Gauss integrals, and parameter-free to establish a stabilized MFE formulation for the non-stationary incompressible Boussinesq equations. We also...In this study, we employ mixed finite element （MFE） method, two local Gauss integrals, and parameter-free to establish a stabilized MFE formulation for the non-stationary incompressible Boussinesq equations. We also provide the theoretical analysis of the existence, uniqueness, stability, and convergence of the stabilized MFE solutions for the stabilized MFE formulation.展开更多
The relationship between the extensional viscosity and material parameters was studied through the analytical formulas of stress and extensional viscosity. The differential equations were solved to obtain the relation...The relationship between the extensional viscosity and material parameters was studied through the analytical formulas of stress and extensional viscosity. The differential equations were solved to obtain the relationship between extensional viscosity and strain rates. The results obtained qualitatively agree with the experimental results. The study makes it practicable to simulate the rheologic behaviors of spinning flow of liquid crystalline polymer using co-rotational Oldroyd fluid B model.展开更多
Bupivacaine encapsulated poly(lactidecoglycolide)nanoparticles is a novel formulation of extended-release of bupivacaine in poly(lactidecoglycolide)matrix.We evaluated the efficacy and safety of bupivacaine nanopartic...Bupivacaine encapsulated poly(lactidecoglycolide)nanoparticles is a novel formulation of extended-release of bupivacaine in poly(lactidecoglycolide)matrix.We evaluated the efficacy and safety of bupivacaine nanoparticles in peripheral analgesia via behavior tests,electrophysiological recordings,pharmacokinetic analysis,and pathology staining by employing the models of uninjured rats and mice.Nanoparticles injection increased the pain thresholds of rats and mice for 21 days.展开更多
Polypropylene(PP)grease holds great potential for special industrial applications.In this study,synthetic conditions,thickener content,and the ratio of two different molecular weight PPs were investigated systematical...Polypropylene(PP)grease holds great potential for special industrial applications.In this study,synthetic conditions,thickener content,and the ratio of two different molecular weight PPs were investigated systematically using a rheometer,scanning electron microscope,X-ray diffraction,Fourier transform infrared spectrometer,oscillating tribometer,and 3D surface profiler measurements.The results showed that suitable synthetic conditions are two quenching cycles,and the synthetic temperature and time is 240℃for 12 h.The rheological analysis showed that thickener content and different proportions of the two PP molecular weights have a significant influence on the rheological properties of PP grease.High molecular weight PP(H-PP)has a stronger thickening ability than low molecular weight PP(L-PP).The higher the amount of H-PP in the fixed thickener content or the higher the thickener content with a specific proportion,the higher the viscoelasticity of PP grease.The tribological performance is related to the rheological properties.The proportion of two different molecular weight PPs in the thickener content should be appropriate;excessive H-PP content leads to lubrication failure.展开更多
Composite hollow shafts are used in power transmission applications due to their high specific stiffness and high specific strength.The dynamic characteristics of these shafts are important for transmission applicatio...Composite hollow shafts are used in power transmission applications due to their high specific stiffness and high specific strength.The dynamic characteristics of these shafts are important for transmission applications.Dynamic modelling of these shafts is generally carried out using Equivalent Modulus Beam Theory(EMBT)and Layerwise Beam Theory(LBT)formulations.The EMBT formulation is modified by considering stacking sequence,shear normal coupling,bending twisting coupling and bending stretching coupling.It is observed that modified EMBT formulation is underestimating the shafts stiffness at lower length/mean diameter(l/dm)ratios.In the present work,a new formulation is developed by adding shear deformation along the thickness direction to the existing modified EMBT formulation.The variation of shear deformation along the thickness direction is found using different shear deformation theories,i.e.,first-order shear deformation theory(FSDBT),parabolic shear deformation theory(PSDBT),trigonometric shear deformation theory(TSDBT),and hyperbolic shear deformation theory(HSDBT).The analysis is performed at l/d_(m) ratios of 5,10,15,20,25,30,35,and 40 for carbon/epoxy composites,E-glass/epoxy composites,and boron/epoxy composite shafts.The results show that new formulation has improved the bending natural frequency of the composite shafts for l/d_(m)<15 in comparison with modified EMBT.The effect of new formulation is more significant for the second and third bending modes of natural frequencies.展开更多
文摘Aim To research the computer optimization design in material formulation. Methods The professional software including experimental design, mathematical modeling and optimization of single and multiple purposes was developed and applied to the formulation design for the flame retardant ethylenepropylene-diene mischpolymer (EPDM) insulation composites. With the aid of equipartition design, the mathematical models were established based on the optimization of the four properties (limiting oxygen index, volume resistance, tensile strength and elongation). Results The models from limited experiments had good significance, and the modeling analysis conclusions were in good agreement with later experiments. The optimization formulation was practically excellent. Conclusion The software enables practically a comprehensive multi-purpose use of material formulation research.
基金supported by the National Science Foundation of China (10871022 11061009+5 种基金 40821092)the National Basic Research Program (2010CB428403 2009CB421407 2010CB951001)Natural Science Foundation of Hebei Province (A2010001663)Chinese Universities Scientific Fund (2009-2-05)
文摘In this article, a reduced mixed finite element （MFE） formulation based on proper orthogonal decomposition （POD） for the non-stationary conduction-convection problems is presented. Also the error estimates between the reduced MFE solutions based on POD and usual MFE solutions are derived. It is shown by numerical examples that the results of numerical computation are consistent with theoretical conclusions. Moreover, it is shown that the reduced MFE formulation based on POD is feasible and efficient in finding numerical solutions for the non-stationary conduction-convection problems.
基金supported by the National Science Foundation of China (11061009,40821092)the National Basic Research Program (2010CB428403,2009CB421407,2010CB951001)Natural Science Foundation of Hebei Province (A2010001663)
文摘A proper orthogonal decomposition（POD） method was successfully used in the reduced-order modeling of complex systems.In this paper,we extend the applications of POD method,namely,apply POD method to a classical finite element（FE） formulation for second-order hyperbolic equations with real practical applied background,establish a reduced FE formulation with lower dimensions and high enough accuracy,and provide the error estimates between the reduced FE solutions and the classical FE solutions and the implementation of algorithm for solving reduced FE formulation so as to provide scientific theoretic basis for service applications.Some numerical examples illustrate the fact that the results of numerical computation are consistent with theoretical conclusions.Moreover,it is shown that the reduced FE formulation based on POD method is feasible and efficient for solving FE formulation for second-order hyperbolic equations.
基金supported by the National Science Foundation of China(11271127 and 11061009)Science Research Program of Guizhou(GJ[2011]2367)the Co-Construction Project of Beijing Municipal Commission of Education
文摘In this paper, we extend the applications of proper orthogonal decomposition （POD） method, i.e., apply POD method to a mixed finite element （MFE） formulation naturally satisfied Brezz-Babu^ka for parabolic equations, establish a reduced-order MFE formulation with lower dimensions and sufficiently high accuracy, and provide the error estimates between the reduced-order POD MFE solutions and the classical MFE solutions and the implementation of algorithm for solving reduced-order MFE formulation. Some numerical examples illustrate the fact that the results of numerical computation are consis- tent with theoretical conclusions. Moreover, it is shown that the new reduced-order MFE formulation based on POD method is feasible and efficient for solving MFE formulation for parabolic equations.
基金Supported by the National Natural Science Foundation of China(11702119,11502071)the Natural Science Foundation of Jiangsu Province(BK20170565)
文摘The Birkhoffian mechanics is more general than the Hamilton mechanics,but only some dynamical systems can be realized as a Birkhoffian formulation.This paper proposes a novel Birkhoffian formulation for the classical Bessel equation.Based on the first method of Santilli,the Birkhoffian formulation of Bessel equation is established under the assumption that the Birkhoffian describes the total physical energy of the corresponding conservative systems.Zero and n-th order classical Bessel equations are studied to verify the effectiveness of the proposed formulation.
基金supported by the National Key Research and Development Program of China(No.2017YFB0306505)supported by the Sinopec Group and the Research Institute of Petroleum Processing.
文摘In this paper the effect of gasoline formulations on fuel economy and emissions were studied,aiming at exploring the optimized fuel formulation that can alleviate energy crisis and greenhouse effect to some extent.Five gasoline blends with same research octane number(RON)were designed and tested on a calibrated gasoline direct injection(GDI)engine under the mapped characteristic conditions.Test results illustrate that the optimized fuel formulation shows good superiority in fuel economy,and reduces carbon dioxide(CO2)emissions at low engine speeds with medium loads.The brake-specific fuel consumption(BSFC)decreased by a maximum value of 3.26%mainly because of the improvement of combustion velocity and the optimization of low heating value.The optimized fuel formulation simultaneously increases total hydrocarbon(THC)emissions.Nevertheless,it also markedly reduces CO2 emissions,reaching the maximum value of 2.34%.The research results can be applied practically by refineries to reduce the CO2 emissions and to alleviate the greenhouse effect.
基金Supported by the Natural Science Foundation of Henan Province（162300410031） Supported by the Excellent Youth Program of the Basic Research Operating Expenses Program of Henan Province （yqpy20140039）
文摘In this paper, a new variational formulation for a reaction-diffusion problem in broken Sobolev space is proposed. And the new formulation in the broken Sobolev space will be proved that it is well-posed and equivalent to the standard Galerkin variational formulation. The method will be helpful to easily solve the original partial differential equation numerically. And the method is novel and interesting, which can be used to deal with some complicated problem, such as the low regularity problem, the differential-integral problem and so on.
文摘The choice of active Trichoderma strains is important in designing effective and safe biocontrol applications. Many species of Trichoderma have multiple strategies for fungal antagonism and indirect effects on plant health, such as growth promotion, systemic resistance induction and fertility improvements. Some strains are powerful antibiotic producers, and their suitability for use in biocontrol systems must be carefully assessed. However, many other active strains have no antibiotic capacity, and these are likely to be more useful in food production systems since they have not adverse effects on important groups of beneficial soil organisms. We have assessed the performance of selected naturally occurring Trichoderma strains (singly and in combination) and developed TUSAL, a mixture of Trichoderma harzianum and T. viride that has demonstrated to be effective against major pathogens in sugar beet and horticulture. TUSAL, has been bulked up and tested under field conditions, showing positive effects on precocity and root development, and increasing the crop production in field trials carried out in different pathosystems. The environmental impact of TUSAL strains on beneficial organisms in the environment were assessed before release, and molecular detection methods were developed to monitor the presence and performance of strains in the field. In addition, Trichoderma protein extracts with high glucanase and chitinase activities, have also been obtained from wild type strains and their effectiveness as biofungicides was tested in laboratory and field conditions, defining the concentration of protein necessary to produce fungicide effects. The genes coding for protein production were introduced into suitable organisms for large-scale production in the laboratory, never released to the environment. The effect of these novel biofungicide proteins was studied separately and synergistically with Trichoderma conidia, and with minimal doses of chemical fungicides. Suitable active Trichoderma strains are being registered in the EU by the company NBT. Both Trichoderma strains and proteins are included in formulations patented as biocontrol agents.
基金Supported by the Specialized Research Project for LS17-2 Semi-submersible Production Platform(LSZX-2020-HN-05-0405).
文摘The taut mooring system using synthetic fiber ropes has overcome the shortcomings such as the large self-weight of the mooring lines and provides better mooring performance for the floating structures.The polyester rope has attracted much attention among numerous synthetic fiber rope materials due to its lightweight,low price,corrosion resistance,and high strength.Thus,the mooring characteristics of it are worth studying.Polyester mooring lines are flexible in deep water,when a marine structure is moored by them,the geometric nonlinearity such as large displacement,large stretch,and large bending deformation,and the material nonlinearity like viscoelastic of the polyester ropes become complex integrated problems to be studied.Considering the nonlinear phenomenon,the simulation and calculation of a polyester line were carried out by the absolute nodal coordinate formulation(ANCF)in this paper since the ANCF method has advantages in dealing with the significant deformation problems of the flexible structures.In addition,a chain mooring line was also simulated for comparison,and the results show that the polyester ropes reduce the self-weight of the mooring lines and provide sufficient mooring strength at the same time,and the nonlinear phenomenon of the polyester ropes is different from that of the chain mooring lines.
基金supported by the University of KwaZulu-Natal(UKZN)Doctoral Scholarshipsupported by the National Research Foundation(NRF)South Africa(S&F-DSI/NRF Free Standing Postdoctoral Fellowship(120784)supported by the National Research Foundation(NRF)South Africa Incentive Funding for Rated Researchers(119903).
文摘Many methods have been proposed in the literature for solving the split variational inequality problem.Most of these methods either require that this problem is transformed into an equivalent variational inequality problem in a product space,or that the underlying operators are co-coercive.However,it has been discovered that such product space transformation may cause some potential difficulties during implementation and its approach may not fully exploit the attractive splitting nature of the split variational inequality problem.On the other hand,the co-coercive assumption of the underlying operators would preclude the potential applications of these methods.To avoid these setbacks,we propose two new relaxed inertial methods for solving the split variational inequality problem without any product space transformation,and for which the underlying operators are freed from the restrictive co-coercive assumption.The methods proposed,involve projections onto half-spaces only,and originate from an explicit discretization of a dynamical system,which combines both the inertial and relaxation techniques in order to achieve high convergence speed.Moreover,the sequence generated by these methods is shown to converge strongly to a minimum-norm solution of the problem in real Hilbert spaces.Furthermore,numerical implementations and comparisons are given to support our theoretical findings.
基金funded by the Centro para el Desarrollo Tecnologico Industrial(CDTI)of the Spanish Ministry of Science and Innovation(IDI-20170503)the Fundacion Cepsa with the Escuela Tecnica Superior de Ingenieros de Minas y Energia of the Universidad Politecnica de Madrid(UPM)。
文摘This work presents the design of a robust foam formulation that tolerates harsh reservoir conditions(high salinity,high divalent ion concentration,high temperature,light oil,and hydrocarbon injection gas)in a sandstone reservoir.For this,we selected anionic Alpha Olefin Sulfonate(AOS)surfactants and studied their synergistic effects in mixtures with zwitterionic betaines to enhance foam performance.The laboratory workflow used to define the best formulation followed a de-risking approach in three consecutive phases.First,(phase 1)the main surfactant(AOS)was selected among a series of commercial candidates in static conditions.Then,(phase 2)the betaine booster to be combined with the previously selected AOS was chosen and their ratio optimized in static conditions.Subsequently,(phase 3)the surfactant/booster ratio was optimized under dynamic conditions in a porous medium in the absence and the presence of oil.As a result of this study,a mixture of an AOS C14-C16 and cocamidopropyl hydroxysultaine(CAPHS)was selected as the one having the best performance.The designed formulation was proven to be robust in a wide range of conditions.It generated a strong and stable foam at reservoir conditions,overcoming variations in salinity and foam quality,and tolerated the presence of oil.
文摘^(14)C-butachlor and ^(14)C-oxadiazon could be released from four kinds of CR formulations into water respectively, and the release percentage of each herbicide increased with time, which could be expressed by regression equations (very obvious positive relationship). The release percentages of ^(14)C-herbicides from CR formulations were related to herbicide CR formulation and water type. Total recovery including ^(14)C-released and ^(14)C-left in formulations for each ^(14)C-herbicide was high at the 56th day after treatment. Some of the released ^(14)C-butachlor in water could be hydrolysed although under dark condition. The rate of hydrolysis was influenced by water type and formulations.
基金Sponsored by the Foundation of Yancheng Teachers University (07YCKL061)
文摘In this article, the author uses the compensated compactness method coupled with some basic ideas of the kinetic formulation developed by Lions, Perthame, Souganidis and Tadmor to give a refined proof for the existence of global entropy solutions to a system of quadratic flux. The fire-new method of reduction of Young measures is a pith of this work.
基金supported by National Science Foundation of China(11271127)Science Research Project of Guizhou Province Education Department(QJHKYZ[2013]207)
文摘A time semi-discrete Crank-Nicolson （CN） formulation with second-order time accuracy for the non-stationary parabolized Navier-Stokes equations is firstly established. And then, a fully discrete stabilized CN mixed finite volume element （SCNMFVE） formu- lation based on two local Gaussian integrals and parameter-free with the second-order time accuracy is established directly from the time semi-discrete CN formulation so that it could avoid the discussion for semi-discrete SCNMFVE formulation with respect to spatial wriables and its theoretical analysis becomes very simple. Finally, the error estimates of SCNMFVE solutions are provided.
基金supported by the National Science Foundation of China(11271127)Science Research Project of Guizhou Province Education Department(QJHKYZ[2013]207)
文摘In this study, we employ mixed finite element （MFE） method, two local Gauss integrals, and parameter-free to establish a stabilized MFE formulation for the non-stationary incompressible Boussinesq equations. We also provide the theoretical analysis of the existence, uniqueness, stability, and convergence of the stabilized MFE solutions for the stabilized MFE formulation.
文摘The relationship between the extensional viscosity and material parameters was studied through the analytical formulas of stress and extensional viscosity. The differential equations were solved to obtain the relationship between extensional viscosity and strain rates. The results obtained qualitatively agree with the experimental results. The study makes it practicable to simulate the rheologic behaviors of spinning flow of liquid crystalline polymer using co-rotational Oldroyd fluid B model.
文摘Bupivacaine encapsulated poly(lactidecoglycolide)nanoparticles is a novel formulation of extended-release of bupivacaine in poly(lactidecoglycolide)matrix.We evaluated the efficacy and safety of bupivacaine nanoparticles in peripheral analgesia via behavior tests,electrophysiological recordings,pharmacokinetic analysis,and pathology staining by employing the models of uninjured rats and mice.Nanoparticles injection increased the pain thresholds of rats and mice for 21 days.
基金the financial support provided by the National Natural Science Foundation of China Project (U21A20315,21978186)the Fund for Shanxi“1331 Project” (1331)。
文摘Polypropylene(PP)grease holds great potential for special industrial applications.In this study,synthetic conditions,thickener content,and the ratio of two different molecular weight PPs were investigated systematically using a rheometer,scanning electron microscope,X-ray diffraction,Fourier transform infrared spectrometer,oscillating tribometer,and 3D surface profiler measurements.The results showed that suitable synthetic conditions are two quenching cycles,and the synthetic temperature and time is 240℃for 12 h.The rheological analysis showed that thickener content and different proportions of the two PP molecular weights have a significant influence on the rheological properties of PP grease.High molecular weight PP(H-PP)has a stronger thickening ability than low molecular weight PP(L-PP).The higher the amount of H-PP in the fixed thickener content or the higher the thickener content with a specific proportion,the higher the viscoelasticity of PP grease.The tribological performance is related to the rheological properties.The proportion of two different molecular weight PPs in the thickener content should be appropriate;excessive H-PP content leads to lubrication failure.
文摘Composite hollow shafts are used in power transmission applications due to their high specific stiffness and high specific strength.The dynamic characteristics of these shafts are important for transmission applications.Dynamic modelling of these shafts is generally carried out using Equivalent Modulus Beam Theory(EMBT)and Layerwise Beam Theory(LBT)formulations.The EMBT formulation is modified by considering stacking sequence,shear normal coupling,bending twisting coupling and bending stretching coupling.It is observed that modified EMBT formulation is underestimating the shafts stiffness at lower length/mean diameter(l/dm)ratios.In the present work,a new formulation is developed by adding shear deformation along the thickness direction to the existing modified EMBT formulation.The variation of shear deformation along the thickness direction is found using different shear deformation theories,i.e.,first-order shear deformation theory(FSDBT),parabolic shear deformation theory(PSDBT),trigonometric shear deformation theory(TSDBT),and hyperbolic shear deformation theory(HSDBT).The analysis is performed at l/d_(m) ratios of 5,10,15,20,25,30,35,and 40 for carbon/epoxy composites,E-glass/epoxy composites,and boron/epoxy composite shafts.The results show that new formulation has improved the bending natural frequency of the composite shafts for l/d_(m)<15 in comparison with modified EMBT.The effect of new formulation is more significant for the second and third bending modes of natural frequencies.
