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Wavelet Multi-Resolution Interpolation Galerkin Method for Linear Singularly Perturbed Boundary Value Problems

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 297-318页

作者： Jiaqun Wang Guanxu Pan Youhe Zhou xiaojing liu School of Management Science and Engineering Anhui University of Finance and EconomicsBengbu233030China Key Laboratory of Mechanics on Disaster and Environment in Western China The Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou730000China

In this study,a wavelet multi-resolution interpolation Galerkin method(WMIGM)is proposed to solve linear singularly perturbed boundary value problems.Unlike conventional wavelet schemes,the proposed algorithm can be readily extended to special node generation techniques,such as the Shishkin node.Such a wavelet method allows a high degree of local refinement of the nodal distribution to efficiently capture localized steep gradients.All the shape functions possess the Kronecker delta property,making the imposition of boundary conditions as easy as that in the finite element method.Four numerical examples are studied to demonstrate the validity and accuracy of the proposedwavelet method.The results showthat the use ofmodified Shishkin nodes can significantly reduce numerical oscillation near the boundary layer.Compared with many other methods,the proposed method possesses satisfactory accuracy and efficiency.The theoretical and numerical results demonstrate that the order of theε-uniform convergence of this wavelet method can reach 5.

关键词： Wavelet multi-resolution interpolation Galerkin singularly perturbed boundary value problems mesh-free method Shishkin node boundary layer

Enhanced stability of nitrogen-doped carbon-supported palladium catalyst for oxidative carbonylation of phenol

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Chinese Journal of Chemical Engineering 2024年第1期65卷 19-28页

作者： xiaojing liu Ruohan Zhao Hao Zhao Zhimiao Wang Fang Li Wei Xue Yanji Wang Hebei Provincial Key Laboratory of Green Chemical Technology and High Efficient Energy Saving School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China Tianjin Key Laboratory of Chemical Process Safety Tianjin 300130China Hebei Industrial Technology Research Institute of Green Chemical Industry Huanghua 061100China

Enhancing the stability of supported noble metal catalysts emerges is a major challenge in both science and industry.Herein,a heterogeneous Pd catalyst(Pd/NCF)was prepared by supporting Pd ultrafine metal nanoparticles(NPs)on nitrogen-doped carbon;synthesized by using F127 as a stabilizer,as well as chitosan as a carbon and nitrogen source.The Pd/NCF catalyst was efficient and recyclable for oxidative carbonylation of phenol to diphenyl carbonate,exhibiting higher stability than Pd/NC prepared without F127 addition.The hydrogen bond between chitosan(CTS)and F127 was enhanced by F127,which anchored the N in the free amino group,increasing the N content of the carbon material and ensuring that the support could provide sufficient N sites for the deposition of Pd NPs.This process helped to improve metal dispersion.The increased metal-support interaction,which limits the leaching and coarsening of Pd NPs,improves the stability of the Pd/NCF catalyst.Furthermore,density functional theory calculations indicated that pyridine N stabilized the Pd^(2+)species,significantly inhibiting the loss of Pd^(2+)in Pd/NCF during the reaction process.This work provides a promising avenue towards enhancing the stability of nitrogen-doped carbon-supported metal catalysts.

关键词： Supported Pd catalyst N-doped carbon Amphiphilic triblock copolymer Pyridinic nitrogen Stability

一种基于血液检测的诊断和预测HBV相关疾病的弹性方法

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Engineering 2024年第1期32卷 174-185页

作者： Gege Hou Yunru Chen xiaojing liu Dong Zhang Zhimin Geng Shubin Si School of Mechanical Engineering Northwestern Polytechnical UniversityXi'an 710072China Key Laboratory of Industrial Engineering and Intelligent Manufacturing(Ministry of Industry and Information Technology) Xi'an 710072China Department of Infectious Diseases The First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an 710061China Department of Hepatobiliary Surgery The First Affiliated Hospital of Xi'an Jiaotong UniversityXi'an 710061China

Chronic hepatitis B virus(HBV)infection,which threatens global public health,is a major contributor to liver-related morbidity and mortality.Examinations for liver diseases related to chronic HBV infection-including laboratory tests,ultrasounds,computed tomography(CT),and liver biopsies-may take up medical resources,particularly since they overlap in most instances.Thus,there is an urgent need to establish an economical and effective diagnosis method in order to streamline the medical process for HBV-related disea ses.Using complex network models constructed based on clinical blood tests,we provide such a method by defining the novel measure of functional resilience to assess patients’liver conditions.By combining network models and dynamics,we discovered the pivotal items and their corresponding thresholds,which can guide further research on preventing disease deterioration in critical states of these diseases.The macro-averaged precision of our method,functional resilience,is84.74%,whereas the macro-averaged precision of physicians’experience without assistance from imaging or biopsy is 55.63%.From an economic perspective,our approach could save the equivalent of at least30 USD per visit for most Chinese patients and at least 400 USD per visit for most US patients,compared with general diagnostic methods.Globally,this will add to savings of at least 10.5 billion USD annually.Our method can comprehensively evaluate the condition of patients’livers and help avert the waste of medical resources during the diagnosis of liver disease by reducing excessive imaging exams.

关键词： HBV-related diseases Functional resilience Improve medical resource utilization Critical states Network

Wavelet multiresolution interpolation Galerkin method for nonlinear boundary value problems with localized steep gradients

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Applied Mathematics and Mechanics(English Edition) 2022年第6期43卷 863-882页

作者： xiaojing liu Youhe ZHOU Jizeng WANG Key Laboratory of Mechanics on Disaster and Environment in Western China(Lanzhou University) the Ministry of EducationCollege of Civil Engineering and MechanicsLanzhou UniversityLanzhou 730000China

The wavelet multiresolution interpolation for continuous functions defined on a finite interval is developed in this study by using a simple alternative of transformation matrix.The wavelet multiresolution interpolation Galerkin method that applies this interpolation to represent the unknown function and nonlinear terms independently is proposed to solve the boundary value problems with the mixed Dirichlet-Robin boundary conditions and various nonlinearities,including transcendental ones,in which the discretization process is as simple as that in solving linear problems,and only common two-term connection coefficients are needed.All matrices are independent of unknown node values and lead to high efficiency in the calculation of the residual and Jacobian matrices needed in Newton’s method,which does not require numerical integration in the resulting nonlinear discrete system.The validity of the proposed method is examined through several nonlinear problems with interior or boundary layers.The results demonstrate that the proposed wavelet method shows excellent accuracy and stability against nonuniform grids,and high resolution of localized steep gradients can be achieved by using local refined multiresolution grids.In addition,Newton’s method converges rapidly in solving the nonlinear discrete system created by the proposed wavelet method,including the initial guess far from real solutions.

关键词： wavelet multiresolution interpolation transcendental nonlinearity localized steep gradient singularly perturbed boundary value problem Troesch’s problem

The uniqueness and superiority of energy utilization in yaks compared with cattle in the highlands:A review

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Animal Nutrition 2023年第1期12卷 138-144页

作者： xiaojing liu Jian Gao Suozhu liu Yanfen Cheng Lizhuang Hao Shujie liu Weiyun Zhu Laboratory of Gastrointestinal Microbiology National Center for International Research on Animal Gut NutritionNanjing Agricultural UniversityNanjing 210095China College of Animal Science Tibet Agricultural and Animal Husbandry UniversityLinzhi 860000China Key Laboratory of Plateau Grazing Animal Nutrition and Feed Science of Qinghai Province State Key Laboratory of Plateau Ecology and AgricultureQinghai Plateau Yak Research CenterQinghai Academy of Animal Science and Veterinary Medicine of Qinghai UniversityXining 810016China

Yaks living on the Qinghai-Tibetan Plateau for a long time have evolved a series of mechanisms to adapt to the unique geographical environment and climate characteristics of the plateau.Compared with other ruminants,yaks have higher energy utilization and metabolic efficiency.This paper presents possible mechanisms responsible for the efficient energy utilization,absorption and metabolism resulting from the unique evolutionary process of yaks.It is hoped that the information discussed in this review will give a better insight into the uniqueness and superiority of yaks in regards to energy metabolism and utilization compared with cattle and open new avenues for the targeted regulation of energy utilization pathways of other ruminants.

关键词： Energy metabolism Energy utilization Fibrous feed Yak

Multiresolution method for bending of plates with complex shapes

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Applied Mathematics and Mechanics(English Edition) 2023年第4期44卷 561-582页

作者： Jizeng WANG Yonggu FENG Cong XU xiaojing liu Youhe ZHOU Key Laboratory of Mechanics on Disaster and Environment in Western China(Lanzhou University) the Ministry of EducationLanzhou 730000China College of Civil Engineering and Mechanics Lanzhou UniversityLanzhou 730000China

A high-accuracy multiresolution method is proposed to solve mechanics problems subject to complex shapes or irregular domains.To realize this method,we design a new wavelet basis function,by which we construct a fifth-order numerical scheme for the approximation of multi-dimensional functions and their multiple integrals defined in complex domains.In the solution of differential equations,various derivatives of the unknown function are denoted as new functions.Then,the integral relations between these functions are applied in terms of wavelet approximation of multiple integrals.Therefore,the original equation with derivatives of various orders can be converted to a system of algebraic equations with discrete nodal values of the highest-order derivative.During the application of the proposed method,boundary conditions can be automatically included in the integration operations,and relevant matrices can be assured to exhibit perfect sparse patterns.As examples,we consider several second-order mathematics problems defined on regular and irregular domains and the fourth-order bending problems of plates with various shapes.By comparing the solutions obtained by the proposed method with the exact solutions,the new multiresolution method is found to have a convergence rate of fifth order.The solution accuracy of this method with only a few hundreds of nodes can be much higher than that of the finite element method(FEM)with tens of thousands of elements.In addition,because the accuracy order for direct approximation of a function using the proposed basis function is also fifth order,we may conclude that the accuracy of the proposed method is almost independent of the equation order and domain complexity.

关键词： multiresolution generalized Coiflet wavelet integral collocation method irregular domain complex shape high accuracy plate bending

A selected population study reveals the biochemical mechanism of intramuscular fat deposition in chicken meat

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Journal of Animal Science and Biotechnology 2022年第5期13卷 1282-1292页

作者： Huanxian Cui Lu liu xiaojing liu Yongli Wang Na Luo Xiaodong Tan Yuting Zhu Ranran liu Guiping Zhao Jie Wen State Key Laboratory of Animal Nutrition Chinese Academy of Agricultural SciencesBeijing 100193China Institute of Animal Science Chinese Academy of Agricultural SciencesBeijing 100193China

Background:Increasing intramuscular fat(IMF)is an important strategy to improve meat quality,but the regulation mechanism of IMF deposition needs to be systematically clarified.Results:A total of 520 chickens from a selected line with improved IMF content and a control line were used to investigate the biochemical mechanism of IMF deposition in chickens.The results showed that the increased IMF would improve the flavor and tenderness quality of chicken meat.IMF content was mainly determined both by measuring triglyceride(TG)and phospholipid(PLIP)in muscle tissue,but only TG content was found to be decisive for IMF deposition.Furthermore,the increase in major fatty acid(FA)components in IMF is mainly derived from TGs(including C16:0,C16:1,C18:1n9c,and C18:2n6c,etc.),and the inhibition of certain very-long-chain FAs would help to IMF/TG deposition.Conclusions:Our study elucidated the underlying biochemical mechanism of IMF deposition in chicken:Prevalent accumulation of long-chain FAs and inhibitions of medium-chain FAs and very long chain FA would jointly result in the increase of TGs with the FA biosynthesis and cellular uptake ways.Our findings will guide the production of high-quality chicken meat.

关键词： Biochemical mechanism Chicken Fatty acid composition Intramuscular fat

Multi-year throughfall reduction enhanced the growth and non-structural carbohydrate storage of roots at the expenses of above-ground growth in a warm-temperate natural oak forest

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Forest Ecosystems 2023年第3期10卷 357-367页

作者： Cuiju liu Zhicheng Chen Shirong liu Kunfang Cao Baoliang Niu xiaojing liu Xiaomin Gao Key Laboratory of Forest Ecology and Environment National Forestry and Grassland AdministrationEcology and Nature Conservation InstituteChinese Academy of ForestryBeijing100091China Baotianman Forest Ecosystem Research Station Nanyang473000China Guangxi Key Laboratory of Forest Ecology and Conservation College of ForestryGuangxi UniversityNanning530004China Henan Baotianman Nature Reserve Administration Neixiang474350China

The more frequent occurrence and severer drought events resulting from climate change are increasingly affecting the physiological performance of trees and ecosystem carbon sequestration in many regions of the world.However,our understanding of the mechanisms underlying the responses and adaption of forest trees to prolonged and multi-year drought is still limited.To address this problem,we conducted a long-term manipulative throughfall reduction(TFR,reduction of natural throughfall by 50%–70%during growing seasons)experiment in a natural oriental white oak(Quercus aliena var.acuteserrata Maxim.)forest under warm-temperate climate.After seven years of continuous TFR treatment,the aboveground growth in Q.aliena var.acuteserrata started to decline.Compared with the control plots,trees in the TFR treatment significantly reduced growth increments of stems(14.2%)and leaf area index(6.8%).The rate of net photosynthesis appeared to be more susceptible to changes in soil water in trees subjected to the TFR than in the control.The TFR-treated trees allocated significantly more photosynthates to belowground,leading to enhanced growth and nonstructural carbohydrates(NSC)storage in roots.The 7-year continuous TFR treatment increased the biomass,the production and the NSC concentration in the fine roots by 53.6%,153.6%and 9.6%,respectively.There were clear trade-offs between the aboveground growth and the fine root biomass and NSC storage in Q.aliena var.acuteserrata trees in response to the multi-year TFR treatment.A negative correlation between the fine root NSC concentration and soil water suggested a strategy of preferential C storage over growth when soil water became deficient;the stored NSC during water limitation would then help promote root growth when drought stress is released.Our findings demonstrate the warm-temperate oak forest adopted a more conservative NSC use strategy in response to long-term drought stress,with enhanced root growth and NSC storage at the expenses of above-ground growth to mitigate climate

关键词： Climate change Carbon allocation Drought stress Forest ecophysiology Nonstructural carbohydrates Warm-temperate forests

A Novel Multiobjective Fireworks Algorithm and Its Applications to Imbalanced Distance Minimization Problems

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IEEE/CAA Journal of Automatica Sinica 2022年第8期9卷 1476-1489页

作者： Shoufei Han Kun Zhu MengChu Zhou xiaojing liu Haoyue liu Yusuf Al-Turki Abdullah Abusorrah College of Computer Science and Technology Nanjing University of Aeronautics and Astronauticsand also with the Collaborative Innovation Center of Novel Software Technology and IndustrializationNanjing 211106China Department of Electrical and Computer Engineering New Jersey Institute of TechnologyNewark NJ 07102 USA Center of Research Excellence in Renewable Energy and Power Systems Department of Electrical and Computer EngineeringFaculty of Engineeringand also with the K.A.CARE Energy Research and Innovation CenterKing Abdulaziz UniversityJeddah 21589Saudi Arabia

Recently,multimodal multiobjective optimization problems(MMOPs)have received increasing attention.Their goal is to find a Pareto front and as many equivalent Pareto optimal solutions as possible.Although some evolutionary algorithms for them have been proposed,they mainly focus on the convergence rate in the decision space while ignoring solutions diversity.In this paper,we propose a new multiobjective fireworks algorithm for them,which is able to balance exploitation and exploration in the decision space.We first extend a latest single-objective fireworks algorithm to handle MMOPs.Then we make improvements by incorporating an adaptive strategy and special archive guidance into it,where special archives are established for each firework,and two strategies(i.e.,explosion and random strategies)are adaptively selected to update the positions of sparks generated by fireworks with the guidance of special archives.Finally,we compare the proposed algorithm with eight state-of-the-art multimodal multiobjective algorithms on all 22 MMOPs from CEC2019 and several imbalanced distance minimization problems.Experimental results show that the proposed algorithm is superior to compared algorithms in solving them.Also,its runtime is less than its peers'.

关键词： Adaptive strategy fireworks algorithm multimodal multiobjective optimization problems(MMOP)