With the proposal of China’s“Carbon Peaking and Carbon Neutrality”policy,the steel industry faces urgent pressure to transition toward green and low-carbon development.However,the persistent reliance on burden stru...With the proposal of China’s“Carbon Peaking and Carbon Neutrality”policy,the steel industry faces urgent pressure to transition toward green and low-carbon development.However,the persistent reliance on burden structure dominated by sinter and pellet in China has led to the high energy consumption and pollution emissions in process before ironmaking,which has increasingly become a major obstacle to the green development of the steel industry.Lump ore can be directly charged into blast furnaces without high-temperature roasting,making it a more environmentally friendly and cleaner raw material option.The utilization of lump ore in blast furnace not only has obvious economic advantages but also achieves significant energy saving and carbon reduction effects.Therefore,an overview of the application of natural lump ore resources was provided,with a focus on its metallurgical properties and the factors influencing them.It further analyzed and summarized strategies for optimizing lump ore performance,particularly highlighting the advantages and technical challenges associated with preheating treatments.Additionally,the application experience,changes in technical and economic indicators,as well as the effects of energy saving and carbon reduction under the condition of a high ratio of lump ore in actual production were elaborated in detail.The results show that after loading lump ore to blast furnaces,the raw material cost is reduced by approximately 50.88 CNY/t,and the CO_(2)emissions from the production of 1 t pig iron can be reduced by 51.18 kg.展开更多
Nonlinear static procedures are widely adopted in structural engineering practice for seismic performance assessment due to their simplicity and computational efficiency.However,their reliability depends heavily on ho...Nonlinear static procedures are widely adopted in structural engineering practice for seismic performance assessment due to their simplicity and computational efficiency.However,their reliability depends heavily on how the nonlinear behaviour of structural components is represented.The recent earthquakes in Albania(2019)and Türkiye(2023)have underscored the need for accurate assessment techniques,particularly for older reinforced concrete buildings with poor detailing.This study quantifies the discrepancies between default and user-defined component modelling in pushover analysis of pre-modern reinforced concrete structures,analysing two representative low-and mid-rise reinforced concrete frame buildings.The lumped plasticity approach incorporates moment-rotation relationships derived from actual member properties and reinforcement configurations,while the distributed plasticity approach uses software-generated default properties based on modern codes.Results show that the distributed plasticity models systematically overestimate both the strength and the deformation capacity by up to 35%compared to lumped plasticity models,especially in buildings with poor detailing and low concrete strength.These findings demonstrate that default software procedures,widely used in practice but not validated for pre-modern structures,produce dangerously unconservative seismic performance estimates.The study provides quantitative evidence of the critical need for tailored modelling strategies that reflect the actual conditions of the existing building stock.展开更多
The rapid increase in traffic loads and frequencies has rendered conventional asphalt pavement inadequate to maintain its durability under tropical climates.This challenge has necessitated the exploration of new sourc...The rapid increase in traffic loads and frequencies has rendered conventional asphalt pavement inadequate to maintain its durability under tropical climates.This challenge has necessitated the exploration of new sources of modified asphalt with enhanced stiffness and superior performance at high temperatures.Natural rubber(NR)is a renewable biopolymer that has received growing interest as a modifier for asphalt binders.Cup lump rubber(CLR),a type of NR,is used to enhance asphalt properties and improve the performance of road pavements.This study evaluates the influence of wax-based surfactants(WS)on CLR-modified asphalt binder(CMB).The assessment focuses on changes in chemical characteristics,rheological behaviour,activation energy,and morphology.Four concentrations of WS(0.1%,0.15%,0.2%,and 0.25%)were incorporated into CMB.Analysis of CMB chemical changes showed that viscosity increased due to higher sulfoxide,carbonyl,and aromatic bond indices.These chemical modifications contributed to improved resistance of the binder to heat-induced deterioration.In both unaged and aged CMB samples,the incorporation of WS reduced the sulfoxide index of the binder.Rheological analysis indicated that CMB improved rutting resistance and anti-ageing performance,while WS further enhanced fatigue resistance.Activation energy analysis suggested that the combination of CMB with 0.15%WS produced the most favourable enhancement.Micrograph results showed that WS improved binder homogeneity and interconnectivity.In conclusion,the findings indicated that incorporating 0.15%WS into CMB enhanced the performance and durability of the asphalt pavement.展开更多
Attributed graph clustering plays a vital role in uncovering hidden network structures,but it presents significant challenges.In recent years,various models have been proposed to identify meaningful clusters by integr...Attributed graph clustering plays a vital role in uncovering hidden network structures,but it presents significant challenges.In recent years,various models have been proposed to identify meaningful clusters by integrating both structural and attribute-based information.However,these models often emphasize node proximities without adequately balancing the efficiency of clustering based on both structural and attribute data.Furthermore,they tend to neglect the critical fuzzy information inherent in attributed graph clusters.To address these issues,we introduce a new framework,Markov lumpability optimization,for efficient clustering of large-scale attributed graphs.Specifically,we define a lumped Markov chain on an attribute-augmented graph and introduce a new metric,Markov lumpability,to quantify the differences between the original and lumped Markov transition probability matrices.To minimize this measure,we propose a conjugate gradient projectionbased approach that ensures the partitioning closely aligns with the intrinsic structure of fuzzy clusters through conditional optimization.Extensive experiments on both synthetic and real-world datasets demonstrate the superior performance of the proposed framework compared to existing clustering algorithms.This framework has many potential applications,including dynamic community analysis of social networks,user profiling in recommendation systems,functional module identification in biological molecular networks,and financial risk control,offering a new paradigm for mining complex patterns in high-dimensional attributed graph data.展开更多
Industrial ebullated-bed is an important device for promoting the cleaning and upgrading of oil products. The lumped kinetic model is a powerful tool for predicting the product yield of the ebullated-bed residue hydro...Industrial ebullated-bed is an important device for promoting the cleaning and upgrading of oil products. The lumped kinetic model is a powerful tool for predicting the product yield of the ebullated-bed residue hydrogenation (EBRH) unit, However, during the long-term operation of the device, there are phenomena such as low frequency of material property analysis leading to limited operating data and diverse operating modes at the same time scale, which poses a huge challenge to building an accurate product yield prediction model. To address these challenges, a data augmentation-based eleven lumped reaction kinetics mechanism model was constructed. This model combines generative adversarial networks, outlier elimination, and L2 norm data filtering to expand the dataset and utilizes kernel principal component analysis-fuzzy C-means for operating condition partitioning. Based on the hydrogenation reaction mechanism, a single and sub operating condition eleven lumped reaction kinetics model of an ebullated-bed residue hydrogenation unit, comprising 55 reaction paths and 110 parameters, was constructed before and after data augmentation. Compared to the single model before data enhancement, the average absolute error of the sub-models under data enhancement division was reduced by 23%. Thus, these findings can help guide the operation and optimization of the production process.展开更多
Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In orde...Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In order to further reduce the size and improve the performance of the proposed filter,defected ground structure(DGS)has been implemented in the filter.Based on this structure,the volume of the inductor is reduced by 60%eficiently compared with the inductor without DGS,and the Q-factor is increased up to 257%compared with the traditional multilayer spiral inductor.The measured results indicate that the designed filter has a very sharp stopband,an insertion loss of 2.3dB,and a return loss of 18.6dB in the passband.The whole volume of the fabricated filter is 0.032入_(g)×0.05入_(g)×0.00075入_(g),where Ag is the guided wavelength of the center frequency.The proposed filter is easily integrated into radio-frequency/microwave circuitry at a low manufacturing cost,especially wireless communication.展开更多
The(2+1)-dimensional generalized coupled nonlinear Schrödinger equations with a four-wave mixing term are studied in this paper,which describe optical solitons in birefringent fibers.Utilizing the Hirota bilinear...The(2+1)-dimensional generalized coupled nonlinear Schrödinger equations with a four-wave mixing term are studied in this paper,which describe optical solitons in birefringent fibers.Utilizing the Hirota bilinear method,we systematically construct single-and double-periodic lump solutions.To provide a detailed insight into the dynamic behavior of the nonlinear waves,we explore diverse mixed solutions,including bright-dark,W-shaped,multi-peak,and bright soliton solutions.Building upon single-periodic lump solutions,we analyze the dynamics of lump waves on both plane-wave and periodic backgrounds using the long-wave limit method.Moreover,we obtain the interaction solutions involving lumps,periodic lumps,and solitons.The interactions among two solitons,multiple lumps,and mixed waves are illustrated and analyzed.Comparative analysis reveals that these multi-lump solutions exhibit richer dynamical properties than conventional single-lump ones.These results contribute to a deeper understanding of nonlinear systems and may facilitate solving nonlinear problems in nature.展开更多
The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.F...The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature.展开更多
Topological states realized in metamaterials have provided a versatile platform for exploring topological physics and enabling novel applications,with topolectrical circuits emerging as a prominent example.However,pre...Topological states realized in metamaterials have provided a versatile platform for exploring topological physics and enabling novel applications,with topolectrical circuits emerging as a prominent example.However,previous research in this feld has primarily focused on lumped-element implementations,while non-lumped microwave circuits remain relatively underexplored.In this work,we design and investigate a one-dimensional non-lumped Su–Schriefer–Heeger topolectrical circuit composed of copper parallel-plate transmission lines and inductors,ofering compatibility with integrated microwave applications.Full-wave microwave simulations in the 0–10 GHz range show excellent agreement with theoretical predictions.The impedance spectrum of a fveunit-cell system displays periodic resonant passbands and stopbands corresponding to bulk states,while distinct high-Q(on the order of 10^(2))topological boundary resonances(TBRs)emerge within the stopbands,indicating the presence of localized edge states.Furthermore,the TBRs vanish when the system is reconfgured into the trivial phase,providing direct evidence of its topological nature.These response characteristics make the proposed resonator a promising candidate for future microwave devices and topological circuit applications.展开更多
本文应用Hirota双线性方法探讨了(2 + 1)维Boiti-Leon-Manna-Pempinelli (BLMP)方程的解及其相互作用。该方法的一个特点是使用对数变换将方程转化为双线性形式,且我们在对数变换中引入了非零常数。本文分析了1-lump波分别与1-kink孤波...本文应用Hirota双线性方法探讨了(2 + 1)维Boiti-Leon-Manna-Pempinelli (BLMP)方程的解及其相互作用。该方法的一个特点是使用对数变换将方程转化为双线性形式,且我们在对数变换中引入了非零常数。本文分析了1-lump波分别与1-kink孤波和2-kink孤波之间的相互作用,揭示了它们的弹性和共振碰撞行为。为了进一步说明这些解的特征,我们利用Mathematica软件提供了详细的三维图示结果。In this study, we investigate the (2 + 1)-dimensional Boiti-Leon-Manna-Pempinelli equations using the Hirota bilinear method. A feature of our approach is the use of a logarithmic transformation to convert the equation into bilinear form with the introduction of a nonzero constant in the transformation. We analyze the interaction dynamics of lump solutions with one and two kink solitons, revealing their elastic and resonant collision behaviors. To further illustrate the characteristics of these solutions, we provide detailed 3D plots using the Mathematica software.展开更多
In this manuscript,a reduced(3+1)-dimensional nonlinear evolution equation is studied.We first construct the bilinear formalism of the equation by using the binary Bell polynomials theory,then explore a lump solution ...In this manuscript,a reduced(3+1)-dimensional nonlinear evolution equation is studied.We first construct the bilinear formalism of the equation by using the binary Bell polynomials theory,then explore a lump solution to the special case for z=x.Furthermore,a more general form of lump solution of the equation is found which possesses seven arbitrary parameters and four constraint conditions.By cutting the lump by the induced soliton(s),lumpoff and instanton/rogue wave solutions are also constructed by the more general form of lump solution.展开更多
We study a simplified(3+1)-dimensional model equation and construct a lump solution for the special case of z=y using the Hirota bilinear method.Then,a more general form of lump solution is constructed,which contains ...We study a simplified(3+1)-dimensional model equation and construct a lump solution for the special case of z=y using the Hirota bilinear method.Then,a more general form of lump solution is constructed,which contains more arbitrary autocephalous parameters.In addition,a lumpoff solution is also derived based on the general lump solutions and a stripe soliton.Furthermore,we figure out instanton/rogue wave solutions via introducing two stripe solitons.Finally,one can better illustrate these propagation phenomena of these solutions by analyzing images.展开更多
For a variable coefficient Kadomtsev-Petviashvili(KP)equation the Lax pair as well as conjugate Lax pair are derived from the Painleve analysis.The N-fold binary Darboux transformation is presented in a compact form.A...For a variable coefficient Kadomtsev-Petviashvili(KP)equation the Lax pair as well as conjugate Lax pair are derived from the Painleve analysis.The N-fold binary Darboux transformation is presented in a compact form.As an application,the multi-lump,higher-order lump and general lump-soliton interaction solutions for the variable coefficient KP equation are obtained.Typical lump structures with amplitudes exponentially decaying to zero as the time tends to infinity and interactions between one lump and one soliton are shown.展开更多
In this paper, we investigate a(2+1)-dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupershmidt equation. The lump waves, lumpoff waves, and rogue waves are presented based on the Hirota bilinear form of this eq...In this paper, we investigate a(2+1)-dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupershmidt equation. The lump waves, lumpoff waves, and rogue waves are presented based on the Hirota bilinear form of this equation. It is worth noting that the moving path as well as the appearance time and place of the lump waves are given. Moreover, the special rogue waves are considered when lump solution is swallowed by double solitons. Finally,the corresponding characteristics of the dynamical behavior are displayed.展开更多
The lump solution is one of the exact solutions of the nonlinear evolution equation.In this paper,we study the lump solution and lump-type solutions of(2+1)-dimensional dissipative Ablowitz-Kaup-Newell-Segure(AKNS)equ...The lump solution is one of the exact solutions of the nonlinear evolution equation.In this paper,we study the lump solution and lump-type solutions of(2+1)-dimensional dissipative Ablowitz-Kaup-Newell-Segure(AKNS)equation by the Hirota bilinear method and test function method.With the help of Maple,we draw three-dimensional plots of the lump solution and lump-type solutions,and by observing the plots,we analyze the dynamic behavior of the(2+1)-dimensional dissipative AKNS equation.We find that the interaction solutions come in a variety of interesting forms.展开更多
基金support by National Natural Science Foundation of China(52474342).
文摘With the proposal of China’s“Carbon Peaking and Carbon Neutrality”policy,the steel industry faces urgent pressure to transition toward green and low-carbon development.However,the persistent reliance on burden structure dominated by sinter and pellet in China has led to the high energy consumption and pollution emissions in process before ironmaking,which has increasingly become a major obstacle to the green development of the steel industry.Lump ore can be directly charged into blast furnaces without high-temperature roasting,making it a more environmentally friendly and cleaner raw material option.The utilization of lump ore in blast furnace not only has obvious economic advantages but also achieves significant energy saving and carbon reduction effects.Therefore,an overview of the application of natural lump ore resources was provided,with a focus on its metallurgical properties and the factors influencing them.It further analyzed and summarized strategies for optimizing lump ore performance,particularly highlighting the advantages and technical challenges associated with preheating treatments.Additionally,the application experience,changes in technical and economic indicators,as well as the effects of energy saving and carbon reduction under the condition of a high ratio of lump ore in actual production were elaborated in detail.The results show that after loading lump ore to blast furnaces,the raw material cost is reduced by approximately 50.88 CNY/t,and the CO_(2)emissions from the production of 1 t pig iron can be reduced by 51.18 kg.
文摘Nonlinear static procedures are widely adopted in structural engineering practice for seismic performance assessment due to their simplicity and computational efficiency.However,their reliability depends heavily on how the nonlinear behaviour of structural components is represented.The recent earthquakes in Albania(2019)and Türkiye(2023)have underscored the need for accurate assessment techniques,particularly for older reinforced concrete buildings with poor detailing.This study quantifies the discrepancies between default and user-defined component modelling in pushover analysis of pre-modern reinforced concrete structures,analysing two representative low-and mid-rise reinforced concrete frame buildings.The lumped plasticity approach incorporates moment-rotation relationships derived from actual member properties and reinforcement configurations,while the distributed plasticity approach uses software-generated default properties based on modern codes.Results show that the distributed plasticity models systematically overestimate both the strength and the deformation capacity by up to 35%compared to lumped plasticity models,especially in buildings with poor detailing and low concrete strength.These findings demonstrate that default software procedures,widely used in practice but not validated for pre-modern structures,produce dangerously unconservative seismic performance estimates.The study provides quantitative evidence of the critical need for tailored modelling strategies that reflect the actual conditions of the existing building stock.
基金the financial support provided under the Fundamental Research Grant Scheme(FRGS),Project Code:FRGS/1/2021/TK01/USM/02/1,which made this research possible,The kind assistance and collaboration of all material suppliers were also gratefully acknowledged.Additional appreciation is extended to the Public Works Department Malaysia for the scholarship provided through the Hadiah Latihan Persekutuan programme for professional and managerial officers pursuing doctoral studies(JPA-1-840622086040)The APC was funded by Prof.Hui Yao from Beijing University of Technology.
文摘The rapid increase in traffic loads and frequencies has rendered conventional asphalt pavement inadequate to maintain its durability under tropical climates.This challenge has necessitated the exploration of new sources of modified asphalt with enhanced stiffness and superior performance at high temperatures.Natural rubber(NR)is a renewable biopolymer that has received growing interest as a modifier for asphalt binders.Cup lump rubber(CLR),a type of NR,is used to enhance asphalt properties and improve the performance of road pavements.This study evaluates the influence of wax-based surfactants(WS)on CLR-modified asphalt binder(CMB).The assessment focuses on changes in chemical characteristics,rheological behaviour,activation energy,and morphology.Four concentrations of WS(0.1%,0.15%,0.2%,and 0.25%)were incorporated into CMB.Analysis of CMB chemical changes showed that viscosity increased due to higher sulfoxide,carbonyl,and aromatic bond indices.These chemical modifications contributed to improved resistance of the binder to heat-induced deterioration.In both unaged and aged CMB samples,the incorporation of WS reduced the sulfoxide index of the binder.Rheological analysis indicated that CMB improved rutting resistance and anti-ageing performance,while WS further enhanced fatigue resistance.Activation energy analysis suggested that the combination of CMB with 0.15%WS produced the most favourable enhancement.Micrograph results showed that WS improved binder homogeneity and interconnectivity.In conclusion,the findings indicated that incorporating 0.15%WS into CMB enhanced the performance and durability of the asphalt pavement.
基金supported by the National Natural Science Foundation of China(Grant No.72571150)Beijing Natural Science Foundation(Grant No.9182015)。
文摘Attributed graph clustering plays a vital role in uncovering hidden network structures,but it presents significant challenges.In recent years,various models have been proposed to identify meaningful clusters by integrating both structural and attribute-based information.However,these models often emphasize node proximities without adequately balancing the efficiency of clustering based on both structural and attribute data.Furthermore,they tend to neglect the critical fuzzy information inherent in attributed graph clusters.To address these issues,we introduce a new framework,Markov lumpability optimization,for efficient clustering of large-scale attributed graphs.Specifically,we define a lumped Markov chain on an attribute-augmented graph and introduce a new metric,Markov lumpability,to quantify the differences between the original and lumped Markov transition probability matrices.To minimize this measure,we propose a conjugate gradient projectionbased approach that ensures the partitioning closely aligns with the intrinsic structure of fuzzy clusters through conditional optimization.Extensive experiments on both synthetic and real-world datasets demonstrate the superior performance of the proposed framework compared to existing clustering algorithms.This framework has many potential applications,including dynamic community analysis of social networks,user profiling in recommendation systems,functional module identification in biological molecular networks,and financial risk control,offering a new paradigm for mining complex patterns in high-dimensional attributed graph data.
基金supported by National Natural Science Foundation of China(Basic Science Center Program:61988101)National Natural Science Foundation of China(62394345,62373155,62173147)the Major Science and Technology Project of Xinjiang(No.2022A01006-4).
文摘Industrial ebullated-bed is an important device for promoting the cleaning and upgrading of oil products. The lumped kinetic model is a powerful tool for predicting the product yield of the ebullated-bed residue hydrogenation (EBRH) unit, However, during the long-term operation of the device, there are phenomena such as low frequency of material property analysis leading to limited operating data and diverse operating modes at the same time scale, which poses a huge challenge to building an accurate product yield prediction model. To address these challenges, a data augmentation-based eleven lumped reaction kinetics mechanism model was constructed. This model combines generative adversarial networks, outlier elimination, and L2 norm data filtering to expand the dataset and utilizes kernel principal component analysis-fuzzy C-means for operating condition partitioning. Based on the hydrogenation reaction mechanism, a single and sub operating condition eleven lumped reaction kinetics model of an ebullated-bed residue hydrogenation unit, comprising 55 reaction paths and 110 parameters, was constructed before and after data augmentation. Compared to the single model before data enhancement, the average absolute error of the sub-models under data enhancement division was reduced by 23%. Thus, these findings can help guide the operation and optimization of the production process.
基金the Shaanxi Provincial Key Research and Development Program(No.2020GY-040)。
文摘Design of a miniaturized lumped-element bandpass filter in multilayer liquid crystal polymer technology is proposed.Fractional bandwidth of the bandpass filter is 20%,operating at a center frequency of 500 MHz.In order to further reduce the size and improve the performance of the proposed filter,defected ground structure(DGS)has been implemented in the filter.Based on this structure,the volume of the inductor is reduced by 60%eficiently compared with the inductor without DGS,and the Q-factor is increased up to 257%compared with the traditional multilayer spiral inductor.The measured results indicate that the designed filter has a very sharp stopband,an insertion loss of 2.3dB,and a return loss of 18.6dB in the passband.The whole volume of the fabricated filter is 0.032入_(g)×0.05入_(g)×0.00075入_(g),where Ag is the guided wavelength of the center frequency.The proposed filter is easily integrated into radio-frequency/microwave circuitry at a low manufacturing cost,especially wireless communication.
基金supported by the Applied Basic Research Program of Shanxi Province,China(Grant Nos.202403021212253 and 202203021221217).
文摘The(2+1)-dimensional generalized coupled nonlinear Schrödinger equations with a four-wave mixing term are studied in this paper,which describe optical solitons in birefringent fibers.Utilizing the Hirota bilinear method,we systematically construct single-and double-periodic lump solutions.To provide a detailed insight into the dynamic behavior of the nonlinear waves,we explore diverse mixed solutions,including bright-dark,W-shaped,multi-peak,and bright soliton solutions.Building upon single-periodic lump solutions,we analyze the dynamics of lump waves on both plane-wave and periodic backgrounds using the long-wave limit method.Moreover,we obtain the interaction solutions involving lumps,periodic lumps,and solitons.The interactions among two solitons,multiple lumps,and mixed waves are illustrated and analyzed.Comparative analysis reveals that these multi-lump solutions exhibit richer dynamical properties than conventional single-lump ones.These results contribute to a deeper understanding of nonlinear systems and may facilitate solving nonlinear problems in nature.
基金the French Defense Innovation Agency (AID)the French Procurement Agency for Armament (DGA)ONERA's scientific direction for funding and supporting the present work
文摘The aim of this paper is to simulate and study the early moments of the reactive ballistics of a large caliber projectile fired from a gun,combining 0D and 2D axisymmetric Computational Fluid Dynamics(CFD)approaches.First,the methodology is introduced with the development of an interior ballistics(IB)lumped parameter code(LPC),integrating an original image processing method for calculating the specific regression of propellant grains that compose the gun propellant.The ONERA CFD code CEDRE,equipped with a Dynamic Mesh Technique(DMT),is then used in conjunction with the developed LPC to build a dedicated methodology to calculate IB.First results obtained on the AGARD gun and 40 mm gun test cases are in a good agreement with the existing literature.CEDRE is also used to calculate inter-mediate ballistics(first milliseconds of free flight of the projectile)with a multispecies and reactive approach either starting from the gun muzzle plane or directly following IB.In the latter case,an inverse problem involving a Latin hypercube sampling method is used to find a gun propellant configuration that allows the projectile to reach a given exit velocity and base pressure when IB ends.The methodology developed in this work makes it possible to study the flame front of the intermediate flash and depressurization that occurs in a base bleed(BB)channel at the gun muzzle.Average pressure variations in the BB channel during depressurization are in good agreement with literature.
基金supported by the National Natural Science Foundation of China(Grant No.11874431)the National Key R&D Program of China(Grant No.2018YFA0306800)。
文摘Topological states realized in metamaterials have provided a versatile platform for exploring topological physics and enabling novel applications,with topolectrical circuits emerging as a prominent example.However,previous research in this feld has primarily focused on lumped-element implementations,while non-lumped microwave circuits remain relatively underexplored.In this work,we design and investigate a one-dimensional non-lumped Su–Schriefer–Heeger topolectrical circuit composed of copper parallel-plate transmission lines and inductors,ofering compatibility with integrated microwave applications.Full-wave microwave simulations in the 0–10 GHz range show excellent agreement with theoretical predictions.The impedance spectrum of a fveunit-cell system displays periodic resonant passbands and stopbands corresponding to bulk states,while distinct high-Q(on the order of 10^(2))topological boundary resonances(TBRs)emerge within the stopbands,indicating the presence of localized edge states.Furthermore,the TBRs vanish when the system is reconfgured into the trivial phase,providing direct evidence of its topological nature.These response characteristics make the proposed resonator a promising candidate for future microwave devices and topological circuit applications.
文摘本文应用Hirota双线性方法探讨了(2 + 1)维Boiti-Leon-Manna-Pempinelli (BLMP)方程的解及其相互作用。该方法的一个特点是使用对数变换将方程转化为双线性形式,且我们在对数变换中引入了非零常数。本文分析了1-lump波分别与1-kink孤波和2-kink孤波之间的相互作用,揭示了它们的弹性和共振碰撞行为。为了进一步说明这些解的特征,我们利用Mathematica软件提供了详细的三维图示结果。In this study, we investigate the (2 + 1)-dimensional Boiti-Leon-Manna-Pempinelli equations using the Hirota bilinear method. A feature of our approach is the use of a logarithmic transformation to convert the equation into bilinear form with the introduction of a nonzero constant in the transformation. We analyze the interaction dynamics of lump solutions with one and two kink solitons, revealing their elastic and resonant collision behaviors. To further illustrate the characteristics of these solutions, we provide detailed 3D plots using the Mathematica software.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11675084 and 11435005)the Fund from the Educational Commission of Zhejiang Province,China(Grant No.Y201737177)+1 种基金Ningbo Natural Science Foundation(Grant No.2015A610159)the K C Wong Magna Fund in Ningbo University
文摘In this manuscript,a reduced(3+1)-dimensional nonlinear evolution equation is studied.We first construct the bilinear formalism of the equation by using the binary Bell polynomials theory,then explore a lump solution to the special case for z=x.Furthermore,a more general form of lump solution of the equation is found which possesses seven arbitrary parameters and four constraint conditions.By cutting the lump by the induced soliton(s),lumpoff and instanton/rogue wave solutions are also constructed by the more general form of lump solution.
基金Project supported by the National Natural Science Foundation of China(Grant No.11971475)。
文摘We study a simplified(3+1)-dimensional model equation and construct a lump solution for the special case of z=y using the Hirota bilinear method.Then,a more general form of lump solution is constructed,which contains more arbitrary autocephalous parameters.In addition,a lumpoff solution is also derived based on the general lump solutions and a stripe soliton.Furthermore,we figure out instanton/rogue wave solutions via introducing two stripe solitons.Finally,one can better illustrate these propagation phenomena of these solutions by analyzing images.
基金the National Natural Science Foundation of China under Grant(11705290,11901538,11875126)the China Postdoctoral Science Foundation funded sixty-fourth batch(2018M640678)+1 种基金the Young Scholar Foundation of ZUT(2018XQG16)Training Plan for Key Young Teachers of Colleges and Universities in Henan Province(2019GGJS143)。
文摘For a variable coefficient Kadomtsev-Petviashvili(KP)equation the Lax pair as well as conjugate Lax pair are derived from the Painleve analysis.The N-fold binary Darboux transformation is presented in a compact form.As an application,the multi-lump,higher-order lump and general lump-soliton interaction solutions for the variable coefficient KP equation are obtained.Typical lump structures with amplitudes exponentially decaying to zero as the time tends to infinity and interactions between one lump and one soliton are shown.
基金Supported by the Postgraduate Research&Practice Innovation Program of Jiansu Province under Grant No.SJKY19 1877the Fundamental Research Funds for the Central University under Grant No.2017XKZD11
文摘In this paper, we investigate a(2+1)-dimensional generalized Konopelchenko-Dubrovsky-Kaup-Kupershmidt equation. The lump waves, lumpoff waves, and rogue waves are presented based on the Hirota bilinear form of this equation. It is worth noting that the moving path as well as the appearance time and place of the lump waves are given. Moreover, the special rogue waves are considered when lump solution is swallowed by double solitons. Finally,the corresponding characteristics of the dynamical behavior are displayed.
文摘The lump solution is one of the exact solutions of the nonlinear evolution equation.In this paper,we study the lump solution and lump-type solutions of(2+1)-dimensional dissipative Ablowitz-Kaup-Newell-Segure(AKNS)equation by the Hirota bilinear method and test function method.With the help of Maple,we draw three-dimensional plots of the lump solution and lump-type solutions,and by observing the plots,we analyze the dynamic behavior of the(2+1)-dimensional dissipative AKNS equation.We find that the interaction solutions come in a variety of interesting forms.
