Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in pet...Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in petroleum fractions. To achieve molecular management in refining processes, a novel model that is based on structure oriented lumping(SOL) and group contribution(GC) methods was proposed in this study. SOL method was applied to describe a petroleum fraction with structural increments, and GC method aimed to estimate molecular properties. The latter was achieved by associating rules between SOL structural increments and GC structures. A three-step reconstruction algorithm was developed to build a representative set of molecules from partial analytical data. First, structural distribution parameters were optimized with several properties. Then, a molecular library was created by using the optimized parameters. In the final step, maximum information entropy(MIE) method was applied to obtain a molecular fraction. Two industrial samples were used to validate the method, and the simulation results of the feedstock properties agreed well with the experimental data.展开更多
Hydrocracking is a catalytic reaction process in the petroleum refineries for converting the higher boiling temperature residue of crude oil into a lighter fraction of hydrocarbons such as gasoline and diesel. In this...Hydrocracking is a catalytic reaction process in the petroleum refineries for converting the higher boiling temperature residue of crude oil into a lighter fraction of hydrocarbons such as gasoline and diesel. In this study, a modified continuous lumping kinetic approach is applied to model the hydro-cracking of vacuum gas oil. The model is modified to take into consideration the reactor temperature on the reaction yield distribution. The model is calibrated by maximizing the likelihood function between the modeled and measured data at four different reactor temperatures. Bayesian approach parameter estimation is also applied to obtain the confidence interval of model parameters by considering the uncertainty associated with the measured errors and the model structural errors. Then Monte Carlo simulation is applied to the posterior range of the model parameters to obtain the 95% confidence interval of the model outputs for each individual fraction of the hydrocracking products. A good agreement is observed between the output of the calibrated model and the measured data points. The Bayesian approach based on the Markov Chain Monte Carlo simulation is shown to be efficient to quantify the uncertainty associated with the parameter values of the continuous lumping model.展开更多
The vibration analysis of Kirchhoff plates requires robust mass lumping schemes to guarantee numerical stability and accuracy.However,existing methods fail to generate symmetric and positive definite mass matrices whe...The vibration analysis of Kirchhoff plates requires robust mass lumping schemes to guarantee numerical stability and accuracy.However,existing methods fail to generate symmetric and positive definite mass matrices when handling rotational degrees of freedom,leading to compromised performance in both time and frequency domains analyses.This study proposes a manifold-based mass lumping scheme that systematically resolves the inertia matrix formulas for rotational/torsional degrees of freedom.By reinterpreting the finite element mesh as a mathematical cover composed of overlapping patches,Hermitian interpolations for plate deflection are derived using partition of unity principles.The manifold-based mass matrix is constructed by integrating the virtual work of inertia forces over these patches,ensuring symmetry and positive definiteness.Numerical benchmarks demonstrate that the manifold-based mass lumping scheme performance can be comparable or better than the consistent mass scheme and other existing mass lumping schemes.This work establishes a unified theory for mass lumping in fourth order plate dynamics,proving that the widely used row-sum method is a special case of the manifold-based framework.The scheme resolves long-standing limitations in rotational/torsional inertia conservation and provides a foundation for extending rigorous mass lumping to 3D shell and nonlinear dynamic analyses.展开更多
In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equ...In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equation,but also analyze the dynamical behaviors of nonlinear local wave propagation in shallow water.Firstly,based on the Hirota bilinear approach,one to four-order soliton solutions of the YTSF equation are obtained,and the effects of different parameters on the amplitude,propagation trajectory,and displacement of solitons are investigated.Secondly,using the long wave limit approach,one to three-order lump solutions and various physical quantities of the YTSF equation are derived.It is found that the real and imaginary parts of the parameter pi dominate the propagation trajectory and the shape of lump waves,respectively.Furthermore,we construct the hybrid solution for the YTSF equation,leading to the conclusion that the interaction between lumps and solitons constitutes an elastic collision.To intuitively understand the dynamic behaviors of these solutions,we conduct numerical simulations to present vivid three-dimensional visualizations.展开更多
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
Hydrogenation technology is an indispensable chemical upgrading process for converting the heavy feedstock into favorable lighter products.In this work,a new kinetic model containing four hydrocarbon lumps(feedstock,d...Hydrogenation technology is an indispensable chemical upgrading process for converting the heavy feedstock into favorable lighter products.In this work,a new kinetic model containing four hydrocarbon lumps(feedstock,diesel,gasoline,cracking gas)was developed to describe the coal tar hydrogenation process,the Levenberg–Marquardt’s optimization algorithm was used to determine the kinetic parameters by minimizing the sum of square errors between experimental and calculated data,the predictions from model validation showed a good agreement with experimental values.Subsequently,an adiabatic reactor model based on proposed lumped kinetic model was constructed to further investigate the performance of hydrogenation fixed-bed units,the mass balance and energy balance within the phases in the reactor were taken into accounts in the form of ordinary differential equation.An application of the reactor model was performed for simulating the actual bench-scale plant of coal tar hydrogenation,the simulated results on the products yields and temperatures distribution along with the reactor are shown to be good consistent with the experimental data.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 13-node quadrilateral and 39-node hexahedral cubic serendipity elements produce nodally integrated positive-definite lumped heat capacity matrices in higher-order finite element analysis.However,these elements dis...The 13-node quadrilateral and 39-node hexahedral cubic serendipity elements produce nodally integrated positive-definite lumped heat capacity matrices in higher-order finite element analysis.However,these elements display severe convergence deterioration in explicit transient heat conduction analysis with lumped heat ca-pacity matrices.This convergence decay is due to the violation of variational integration consistency by the standard Galerkin formulation with lumped heat capacity matrices.This issue is resolved by introducing the boundary-enhanced Galerkin weak form that incorporates the elemental boundary contribution in the discrete finite element formulation.Subsequently,it is theoretically proven that a direct nodal integration identically fulfills the variational integration consistency in the context of the boundary-enhanced Galerkin weak form.The proposed variationally consistent nodal integration therefore enables optimal convergence for explicit transient heat conduction analysis with lumped heat capacity matrices.The efficacy of the proposed variationally con-sistent nodal integration formulation for the 13-node quadrilateral and 39-node hexahedral cubic elements is thoroughly demonstrated via numerical examples.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
基金Supported by the National Natural Science Foundation of China(U1462206)
文摘Molecular management is a promising technology to face challenges in the refining industry, such as more stringent requirements for product oil and heavier crude oil, and to maximize the value of every molecule in petroleum fractions. To achieve molecular management in refining processes, a novel model that is based on structure oriented lumping(SOL) and group contribution(GC) methods was proposed in this study. SOL method was applied to describe a petroleum fraction with structural increments, and GC method aimed to estimate molecular properties. The latter was achieved by associating rules between SOL structural increments and GC structures. A three-step reconstruction algorithm was developed to build a representative set of molecules from partial analytical data. First, structural distribution parameters were optimized with several properties. Then, a molecular library was created by using the optimized parameters. In the final step, maximum information entropy(MIE) method was applied to obtain a molecular fraction. Two industrial samples were used to validate the method, and the simulation results of the feedstock properties agreed well with the experimental data.
文摘Hydrocracking is a catalytic reaction process in the petroleum refineries for converting the higher boiling temperature residue of crude oil into a lighter fraction of hydrocarbons such as gasoline and diesel. In this study, a modified continuous lumping kinetic approach is applied to model the hydro-cracking of vacuum gas oil. The model is modified to take into consideration the reactor temperature on the reaction yield distribution. The model is calibrated by maximizing the likelihood function between the modeled and measured data at four different reactor temperatures. Bayesian approach parameter estimation is also applied to obtain the confidence interval of model parameters by considering the uncertainty associated with the measured errors and the model structural errors. Then Monte Carlo simulation is applied to the posterior range of the model parameters to obtain the 95% confidence interval of the model outputs for each individual fraction of the hydrocracking products. A good agreement is observed between the output of the calibrated model and the measured data points. The Bayesian approach based on the Markov Chain Monte Carlo simulation is shown to be efficient to quantify the uncertainty associated with the parameter values of the continuous lumping model.
基金supported by National Natural Science Foundation of China(Grant Nos.42107214 and 52130905)the Natural Science Foundation of Chongqing(No.CSTB2024NSCQMSX0740)the Henan Province Science and Technology Research Projects(No.252102220050).
文摘The vibration analysis of Kirchhoff plates requires robust mass lumping schemes to guarantee numerical stability and accuracy.However,existing methods fail to generate symmetric and positive definite mass matrices when handling rotational degrees of freedom,leading to compromised performance in both time and frequency domains analyses.This study proposes a manifold-based mass lumping scheme that systematically resolves the inertia matrix formulas for rotational/torsional degrees of freedom.By reinterpreting the finite element mesh as a mathematical cover composed of overlapping patches,Hermitian interpolations for plate deflection are derived using partition of unity principles.The manifold-based mass matrix is constructed by integrating the virtual work of inertia forces over these patches,ensuring symmetry and positive definiteness.Numerical benchmarks demonstrate that the manifold-based mass lumping scheme performance can be comparable or better than the consistent mass scheme and other existing mass lumping schemes.This work establishes a unified theory for mass lumping in fourth order plate dynamics,proving that the widely used row-sum method is a special case of the manifold-based framework.The scheme resolves long-standing limitations in rotational/torsional inertia conservation and provides a foundation for extending rigorous mass lumping to 3D shell and nonlinear dynamic analyses.
基金Supported by the National Natural Science Foundation of China(12001424,12271324)the Natural Science Basic research program of Shaanxi Province(2021JZ-21)+1 种基金the China Postdoctoral Science Foundation(2020M673332)Xi’an University,Xi’an Science and Technology Plan Wutongshu Technology Transfer Action Innovation Team(25WTZD07)。
文摘In this article,by employing the Hirota bilinear approach and the long wave limit method,we not only derive soliton solutions,lump solutions,and hybrid solutions for the(2+1)-dimensional Yu-Toda-Sasa-Fukuyama(YTSF)equation,but also analyze the dynamical behaviors of nonlinear local wave propagation in shallow water.Firstly,based on the Hirota bilinear approach,one to four-order soliton solutions of the YTSF equation are obtained,and the effects of different parameters on the amplitude,propagation trajectory,and displacement of solitons are investigated.Secondly,using the long wave limit approach,one to three-order lump solutions and various physical quantities of the YTSF equation are derived.It is found that the real and imaginary parts of the parameter pi dominate the propagation trajectory and the shape of lump waves,respectively.Furthermore,we construct the hybrid solution for the YTSF equation,leading to the conclusion that the interaction between lumps and solitons constitutes an elastic collision.To intuitively understand the dynamic behaviors of these solutions,we conduct numerical simulations to present vivid three-dimensional visualizations.
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the Joint Funds of the National Natural Science Foundation of China(PRIKY15013 and 2015D-5006-0406)the National Natural Science Foundation of China(No.21808223).
文摘Hydrogenation technology is an indispensable chemical upgrading process for converting the heavy feedstock into favorable lighter products.In this work,a new kinetic model containing four hydrocarbon lumps(feedstock,diesel,gasoline,cracking gas)was developed to describe the coal tar hydrogenation process,the Levenberg–Marquardt’s optimization algorithm was used to determine the kinetic parameters by minimizing the sum of square errors between experimental and calculated data,the predictions from model validation showed a good agreement with experimental values.Subsequently,an adiabatic reactor model based on proposed lumped kinetic model was constructed to further investigate the performance of hydrogenation fixed-bed units,the mass balance and energy balance within the phases in the reactor were taken into accounts in the form of ordinary differential equation.An application of the reactor model was performed for simulating the actual bench-scale plant of coal tar hydrogenation,the simulated results on the products yields and temperatures distribution along with the reactor are shown to be good consistent with the experimental data.
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supported by the National Natural Science Foundation of China(Grant Nos.12372201 and 12072302).
文摘The 13-node quadrilateral and 39-node hexahedral cubic serendipity elements produce nodally integrated positive-definite lumped heat capacity matrices in higher-order finite element analysis.However,these elements display severe convergence deterioration in explicit transient heat conduction analysis with lumped heat ca-pacity matrices.This convergence decay is due to the violation of variational integration consistency by the standard Galerkin formulation with lumped heat capacity matrices.This issue is resolved by introducing the boundary-enhanced Galerkin weak form that incorporates the elemental boundary contribution in the discrete finite element formulation.Subsequently,it is theoretically proven that a direct nodal integration identically fulfills the variational integration consistency in the context of the boundary-enhanced Galerkin weak form.The proposed variationally consistent nodal integration therefore enables optimal convergence for explicit transient heat conduction analysis with lumped heat capacity matrices.The efficacy of the proposed variationally con-sistent nodal integration formulation for the 13-node quadrilateral and 39-node hexahedral cubic elements is thoroughly demonstrated via numerical examples.
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.
