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MONOTONICITY CORRECTIONS FOR NINE-POINT SCHEME OF DIFFUSION EQUATIONS

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Journal of Computational Mathematics 2024年第5期42卷 1305-1327页

作者： Wang kong Zhenying Hong Guangwei Yuan Zhiqiang Sheng School of Mathematics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Key Laboratory of Mathematical Modelling and High Performance Computing of Air Vehicles(NUAA) MIITNanjing 211106China Laboratory of Computational Physics Institute of Applied Physics and Computational MathematicsBeijing 100088China HEDPS Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China

In this paper,we present a nonlinear correction technique to modify the nine-point scheme proposed in[SIAM ***.,30:3(2008),1341-1361]such that the resulted scheme preserves the *** first express the flux by the cell-centered unknowns and edge unknowns based on the stencil of the nine-point ***,we use a nonlinear combination technique to get a monotone *** order to obtain a cell-centered finite volume scheme,we need to use the cell-centered unknowns to locally approximate the auxiliary *** present a new method to approximate the auxiliary unknowns by using the idea of an improved multi-points flux *** numerical results show that the new proposed scheme is robust,can handle some distorted grids that some existing finite volume schemes could not handle,and has higher numerical accuracy than some existing positivity-preserving finite volume schemes.

关键词： Monotonicity corrections Diffusion equation Improved MPFA Distorted meshes

Two kinds of average approximation accuracy

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CAAI Transactions on Intelligence technology 2024年第2期9卷 481-490页

作者： Qingzhao kong Wanting Wang Dongxiao Zhang Wenbin Zhang Department of science Jimei UniversityXiamenChina Digital Fujian Big Data Modeling and Intelligent Computing Institute Jimei UniversityXiamenChina Department of Computer science Michigan Technological UniversityHoughtonMichiganUSA

Rough set theory places great importance on approximation accuracy,which is used to gauge how well a rough set model describes a target ***,traditional approximation accuracy has limitations since it varies with changes in the target concept and cannot evaluate the overall descriptive ability of a rough set *** overcome this,two types of average approximation accuracy that objectively assess a rough set model’s ability to approximate all information granules is *** first is the relative average approximation accuracy,which is based on all sets in the universe and has several basic *** second is the absolute average approximation accuracy,which is based on undefinable sets and has yielded significant *** also explore the relationship between these two types of average approximation ***,the average approximation accuracy has practical applications in addressing missing attribute values in incomplete information tables.

关键词： rough sets rough set theory

Distinct enhancer-promoter modes determine Sox2 regulation in mouse pluripotent cells

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Genes & Diseases 2024年第1期11卷 26-29页

作者： Lei Huang Xiusheng Zhu Qing Li Dashuai kong Qitong Huang Jing Luo Siyuan kong Yanling Peng Yubo Zhang Animal Functional Genomics Group Shenzhen BranchGuangdong Laboratory for Lingnan Modern AgricultureKey Laboratory of Livestock and Poultry Multi-omics of MAPAShenzhen Agricultural Genome Research InstituteChinese Academyof Agricultural SciencesShenzhenGuangdong 518120China Animal Breeding and Genomics Wageningen University&ResearchWageningen 6708PBNetherlands College of Life science and Engineering Foshan UniversityFoshanGuangdong 528231China School of Life sciences Henan UniversityKaifengHenan 475004China

Sox2 is a key transfer factor for maintaining pluripotency and self-renewal in embryonic stem cells(ESCs),1 though the mechanism of its transcriptional regulation in ESCs has not been fully *** enhancer-promoter interactions are vital for Sox2 transcription activity in ***,how these diverse interactions individually influence Sox2 gene regulation in mouse ESCs remains *** studies found that three distal enhancers(termed E1,E2,and E3)interact with Sox2 promoter?(Fig.1A;Fig.S1A,and Table S1).

关键词： Sox2 regulation distal

Exploring differentiated improvement strategies of cultivated land quality in China

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Frontiers of Agricultural science and Engineering 2024年第2期11卷 282-291页

作者： Wenguang CHEN Xiangbin kong Yubo LIAO College of Land science and technology China Agricultural UniversityBeijing 100193China

Quality is the core feature of cultivated land. In the face of deteriorating cultivated land quality and growing food demand, improving cultivated land quality is a top priority for guaranteeing the sustainable use of resources and national food security. Cultivated land quality in the new era can be considered in four dimensions: suitability, contiguity, resistance and ecological stress. Cultivated land suitability in China shows a decreasing trend from east to west, cultivated land contiguity is high in the north-east and low in the south-west. In terms of cultivated land resistance, the number of strongly and weakly resistant cropping fields is small and spatially clustered. Cultivated land with ecological stress is mainly located in the northern region. Based on the current situation of cultivated land quality and the strategic needs of national high-quality development, China's future goals for improving cultivated land quality include four aspects: promoting the sustainable use of resources,improving the economic benefits of farming, coping with extreme meteorological disasters and meeting the transition of the food *** the backdrop of a volatile international environment and high domestic demand for food, China should guarantee a safe supply of staples, a stable supply of animal feed and a moderate supply of high-nutrient food. In the future, China should create three major food production spaces: highstandard, low-to medium-yield, and marginal cultivated land. China urgently needs to construct three paths to implement the goal of improving cultivated land quality, namely the development of high-standard cultivated land with the core of spatial optimization, resilience enhancement and scale coupling,the transformation of low-to medium-yield cultivated land with the core of obstacle elimination, tenure adjustment, ecological sustainable, and the conservation development of marginal cultivated land with a focus on sustainable use.

关键词： China cultivated land quality differentiated improvement food security

Dynamical distribution of continuous service time model involving non-Maxwellian collision kernel and value functions

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Chinese Physics B 2024年第9期33卷 340-348页

作者： Minfang Zhao Lingting kong Miao Liu Shaoyong Lai School of Mathematics and Statistics Yili Normal UniversityYining 835000China Institute of Applied Mathematics Yili Normal UniversityYining 835000China School of Mathematics Southwestern University of Finance and EconomicsChengdu 611130China

The distribution of continuous service time in call centers is investigated.A non-Maxwellian collision kernel combining two different value functions in the interaction rule are used to describe the evolution of continuous service time,*** the statistical mechanical and asymptotic limit methods,Fokker–Planck equations are derived from the corresponding Boltzmann-type equations with non-Maxwellian collision *** steady-state solutions of the Fokker–Planck equation are obtained in exact *** experiments are provided to support our results under different parameters.

关键词： kinetic theory service time Fokker–Planck equation value function

Temperature prediction model in multiphase flow considering phase transition in the drilling operations

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Petroleum science 2024年第3期21卷 1969-1979页

作者： Yang Zhang Yong-An Li Xiang-Wei kong Hao Liu Teng-Fei Sun College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100027China School of Petroleum Engineering Yangtze UniversityWuhan430000HubeiChina

The study considers gas compression properties,gas slippage,back pressure(BP),phase transition(PT),well depth,and differences in gas-liquid physical properties.A new temperature model for multiphase flow is proposed by considering phase transition in the drilling *** mathematical model of multiphase flow is solved using the finite difference method with annulus mesh division for grid nodes,and a module for multiphase flow calculation and analysis is *** results indicate that the temperature varies along the annulus with the variation of gas influx at the bottom of the *** the process of controlled pressure drilling,as gas slips along the annulus to the wellhead,its volume continuously expands,leading to an increase in the gas content within the annulus,and consequently,an increase in the pressure drop caused by gas *** temperature increases with the increase in BP and decreases in gas influx rate and wellbore *** gas influx,the thermal conductivity coefficient for the gas-drilling mud two phases is significantly weakened,resulting in a considerable change in temperature along the *** the context of MPD,the method of slightly changing the temperature along the annulus by controlling the back pressure is feasible.

关键词： Managed pressure drilling Phase transition Temperature Gas-drilling mud two phase

Acoustic Velocity-Based Inversion of the Physical Properties of Sea Ice in the Central Arctic Region

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Journal of Ocean university of China 2024年第5期23卷 1213-1220页

作者： kong Yadong XING Junhui XU Haowei XU Chong Key Laboratory of Submarine Geosciences and Prospecting Techniques Ministry of Education(MOE)and College of Marine GeosciencesOcean University of ChinaQingdao 266100China Laboratory for Marine Mineral Resources Qingdao Marine Science and Technology CenterQingdao 266071China

Studying the Arctic sea ice contributes to a comprehensive understanding of the climate system in polar regions and offers valuable insights into the interplay between polar climate change and the global climate and *** of the key research aspects is the investigation of the temperature,salinity,and density parameters of sea ice to obtain essential *** the 11th Chinese National Arctic Research Expedition,acoustic velocity was measured on an ice core at a short-term ice station,however,temperature,salinity,and density were not *** the present work,we utilized a genetic algorithm to invert these obtained acoustic velocity data to sea ice temperature,salinity,and density parameters on the basis of the relationship between acoustic velocity and the physical properties of Arctic summer sea *** validated the effectiveness of this inversion procedure by comparing its findings with those of other *** results indicate that within the normalized depth range of 0.43-0.94,the ranges for temperature,salinity,and density are -0.48--0.29℃,1.63-3.35,and 793.1-904.1 kg m^(-3),respectively.

关键词： acoustic velocity Arctic sea ice inversion of sea ice properties genetic algorithm

A TRUST-REGION METHOD FOR SOLVING TRUNCATED COMPLEX SINGULAR VALUE DECOMPOSITION

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Journal of Computational Mathematics 2024年第4期42卷 999-1031页

作者： Jiaofen Li Lingchang kong Xuefeng Duan Xuelin Zhou Qilun Luo School of Mathematics and Computing science Guangxi Colleges and Universities Key Laboratory of Data Analysis and ComputationGuangxi Key Laboratory of Automatic Detecting Technology and InstrumentsGuilin University of Electronic TechnologyCenter for Applied Mathematics of Guangxi(GUET)Guilin 541004China School of Mathematical sciences South China Normal UniversityGuangzhou 510000China School of Mathematics and Computing science Guilin University of Electronic TechnologyGuilin 541004China School of Mathematics and Computing science Guangxi Colleges and Universities Key Laboratory of Data Analysis and ComputationGuilin University of Electronic TechnologyCenter for Applied Mathematics of Guangxi(GUET)Guilin 541004China School of Mathematics and Statistics Yunan UniversityKunming 650000China

The truncated singular value decomposition has been widely used in many areas of science including engineering,and statistics,*** this paper,the original truncated complex singular value decomposition problem is formulated as a Riemannian optimiza-tion problem on a product of two complex Stiefel manifolds,a practical algorithm based on the generic Riemannian trust-region method of Absil et *** presented to solve the underlying problem,which enjoys the global convergence and local superlinear conver-gence *** experiments are provided to illustrate the efficiency of the proposed *** with some classical Riemannian gradient-type methods,the existing Riemannian version of limited-memory BFGS algorithms in the MATLAB toolbox Manopt and the Riemannian manifold optimization library ROPTLIB,and some latest infeasible methods for solving manifold optimization problems,are also provided to show the merits of the proposed approach.

关键词： Truncated singular value decomposition Riemannian optimization Trust-region method

Dealuminated Hβ zeolite for selective conversion of fructose to furfural and formic acid

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Green Energy & Environment 2024年第2期9卷 311-320页

作者： Rui Li Qixuan Lin Junli Ren Xiaobao Yang Yingxiong Wang Lingzhao kong State Key Laboratory of Pulp and Paper Engineering School of Light Industry and EngineeringSouth China University of TechnologyGuangzhou510640China Institute of Coal Chemistry Chinese Academy of Sciences27 South Taoyuan RoadTaiyuan030001China CAS Key Laboratory of Low-Carbon Conversion science and Engineering Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China School of Environmental science and technology Suzhou university of science and technology Suzhou Jiangsu215009China

The fructose-to-furfural transformation is facing major challenges in the selectivity and high efficiency. Herein, we have developed a simple and effective approach for the selective conversion of fructose to furfural using Hβ zeolite modified by organic acids for dealuminization to regulate its textural and acidic properties. It was found that citric acid-dealuminized Hβ zeolite possessed high specific surface areas, wide channels and high Brønsted acid amount, which facilitated the selective conversion of fructose to furfural with a maximum yield of 76.2% at433 K for 1 h in the γ-butyrolactone(GBL)-H_(2)O system, as well as the concomitant formation of 83.0% formic acid. The^(13)C-isotope labelling experiments and the mechanism revealed that the selective cleavage of C1–C2 or C5–C6 bond on fructose was firstly occurred to form pentose or C5 intermediate by weak Brønsted acid, which was then dehydrated to furfural by strong Brønsted acid. Also this dealuminized Hβ catalyst showed the great recycling performance and was active for the conversion of glucose and mannose.

关键词： Fructose Dealuminated-Hb zeolite Selective conversion Furfural