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Investigating effect of coke porosity on blast furnace performance based on multi-physical fields

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Journal of Iron and Steel Research International 2024年第2期31卷 357-367页

作者： ji Chen Zhao Lei Zhe Yao li Wang Qiang ling Ping Cui Anhui Province Key Laboratory of Coal Clean Conversion and High Valued Utilization School of Chemistry and Chemical EngineeringAnhui University of TechnologyMa’anshan243002AnhuiChina Shanxi Academy of Printing Technology Research Institute Co. Ltd.Xi’an710077ShaanxiChina

Reducing coke use is an effective measure to reduce carbon emission and energy consumption in the blast furnace(BF)***,BF is a high-temperature moving bed reactor,where complex physical transformations coupled with complicated reactions *** makes it challenging to investigate the factors determining BF performance with the conventional method.A multi-physical field coupling mathematical model of BF was thus developed to describe its mass and heat transfer as well as its intrinsic ***,the proposed model was validated with the production *** coupling conditions,influences of dominating reactions on BF performance(temperature distribution,gas distribution,iron formation reaction,and direct reduction degree)were *** results indicated that coke combustion,indirect reduction,and direct reduction of iron ore mainly took place nearby the shaft tuyere,cohesive zone,and dripping zone,***,the rate of coke solution loss reaction was increased with the rising coke porosity in the cohesive *** the effect of coke porosity on the efficiency and stability of BF,the coke porosity of 0.42 was regarded as a reasonable value.

关键词： Blast furnace Mathematical model Multi-physical field Simulation Coke porosity

Understanding and improving Yangtze River Basin summer precipitation prediction using an optimal multi-Physics ensemble

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Frontiers of Earth Science 2024年第1期18卷 256-277页

作者： Yang ZHAO Fengxue QIAO Xin-Zhong liANG jinhua YU Climate Environment and Sustainability CenterNanjing University of Information Science and TechnologyNanjing 210044China Key Laboratory of Geographic Information Science(Ministry of Education) East China Normal UniversityShanghai 200241China School of Geographic Sciences East China Normal UniversityShanghai 200241China department of Atmospheric and Oceanic Science University of MarylandCollege Park MD 20740USA Earth System Science Interdisciplinary Center University of MarylandCollege Park MD 20740USA Key Laboratory of Meteorological Disaster(KLME)(Ministry of Education)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science and TechnologyNanjing 210044China

This study employs the regional Climate-Weather Research and Forecasting model(CWRF)to first investigate the primary physical mechanisms causing biases in simulating summer precipitation over the Yangtze River Basin(YRB),and then enhance its predictive ability through an optimal multi-physics ensemble *** CWRF 30-km simulations in china are compared among 28 combinations of varying physics parameterizations during 1980−***-term average summer biases in YRB precipitation are remotely correlated with those of large-scale *** teleconnections of biases are highly consistent with the observed correlation patterns between interannual variations of precipitation and circulations,despite minor shifts in their primary action *** YRB precipitation aligns with a southward shifted East Asian westerly jet,an intensified low-level southerly flow south of YRB,and a south-eastward shifted South Asian high,alongside higher moisture availability over ***,decreased YRB precipitation corresponds to an opposite circulation *** CWRF control configuration using the ensemble cumulus parameterization(ECP),compared to other cumulus schemes,best captures the observed YRB precipitation characteristics and associated circulation *** ECP with the Morrison or Morrison-aerosol microphysics and the CCCMA or CAML radiation schemes enhances the overall CWRF *** to the control CWRF,the ensemble average of these skill-enhanced physics configurations more accurately reproduces YRB summer precipitation’s spatial distributions,interannual anomalies,and associated circulation *** Bayesian Joint Probability calibration to these configurations improves the ensemble’s spatial distributions but compromises its interannual anomalies and teleconnection *** findings highlight substantial potential for refining the representation of climate system physics to improve YRB precipitation *** is notabl

关键词： physics parameterization regional climate model downscaling skill enhancement multi-physics ensemble teleconnection bias reduction

linear estimation and distribution of the limit cycles bifurcated from a kind of degenerate polycycles

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Science china mathematics 2007年第3期50卷 334-344页

作者： li-qin ZHAO department of mathematics, Beijing normal university, Beijing 100875, china department of mathematics Beijing Normal University Beijing 100875 China

In this paper, we investigate the number and the distribution of the limit cycles bifurcated from a kind of degenerate planar polycycles through three singular points: a saddle-node P 0, a fine saddle P 1 with finite order m ∈ N, a contractive (attracting) saddle P 2 with the hyperbolicity ratio q 2(0) ? Q. The connection between P 0 and P 1 is of hh-type and the connection between P 0 and P 2 is of hp-type. It is assumed that the connections between P 0 to P 2 and P 0 to P 1 keep unbroken. We obtain that the cyclicity of this polycycle is not more than 3m + 1, which is linearly dependent on the order of the resonant saddle P 1. We also show that the cyclicity is not more than m + 3 if q 2(0) > m, and that the nearer q 2(0) is close to 1, the more the limit cycles are bifurcated.

关键词： degenerate polycycle cyclicity finitely-smooth normal form transition map 34C05 34C23 58F14

Optimal Scheduling of Regional Integrated Energy Systems Considering Hybrid Demand Response

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CSEE Journal of Power and Energy Systems 2024年第3期10卷 1208-1219页

作者： Ganyun Lyu bin Cao Dexiang jia Nan Wang Jun li Guangyu Chen department of Electrical Engineering Nanjing Institute of TechnologyNanjing 211167China State Grid Energy Research Institute Co. LTDBeijing 102209China State Grid Integrated Energy Service Group Co. LTDBeijing 100032China IEEE CSEE

Flexible load can optimize the load curve,which is an important means to promote renewable energy *** peculiarities of electricity,heat,cooling and gas loads are analyzed in this paper,considering the fuzzy degree of human perception for water temperature,and the characteristic model of hot water load is *** the fuzzy degree of human perception of ambient temperature,the characteristic model of cooling load is established by using PMV and PPD ***,considering four combinations of cut load,translatable load,transferable load and alternative load,and considering the coupling relationship of composite parts,different response models of load are established *** the minimum cost of the system,including operation and compensation costs as the objective function,the optimization scheduling model of the regional integrated energy system is established,and the Gurobi solver is used for simulation analysis to solve the optimal output and load response curve of each piece of *** results show that the load curve can be optimized,the flexible regulation ability of the regional integrated energy system can be enhanced,the energy loss of the system can be reduced,and the wind power consumption ability of the system can be increased by considering the integrated demand response.

关键词： Alternative load day ahead optimal scheduling integrated demand response PMV and PPD index regional integrated energy system

ON THE APPROXIMATELY SIMILARITY OF OPERATORS

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Chinese Annals of mathematics,Series B 1998年第4期19卷 465-472页

作者： WEI GUOQIANG (department of mathematics, East china normal university, Shanghai 200062, china.) E china normal Univ Dept Math Shanghai 200062 Peoples R China

The author shows that a rank-preserving *-isorporphism between separable C*-algebras with unity is approximately equivalent to the identity representation. Some applications are made for approximately similarity of n-... 详细信息

关键词： C*-algebra Rank-preserving *-isomorphism Approximately equevalent,Approximately similar n-tuples of operators

MULTIPliCITY OF PERIODICSOLUTIONS OF DUFFING'S EQUATIONSWITH liPSCHITZIAN CONDITIONMULTIPliCITY OF PERIODICSOLUTIONS OF DUFFING'S EQUATIONS WITH liPSCHITZIAN CONDITION

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Chinese Annals of mathematics,Series B 2000年第4期21卷 479-488页

作者： WANG ZAIHONG (department of mathematics, Capital normal university, Beijing 100037, china.) department of mathematics Capital Normal University Beijing 100037 China

This paper deals with the existence and multiplicity of periodic solutions of Duffing equations x + g(x) = p(t). The author proves an infinity of periodic solutions to the periodically forced nonlinear Duffing equations provided that g(x) satisfies the globally lipschitzian condition and the time-mapping satisfies the weaker oscillating property.

关键词： Periodic solution Time mapping Poincare-Birkhoff twist theorem

Clinical study on the relationship between liver cirrhosis,ascites,and hyponatremia

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 751-758页

作者： Xuan-ji li Hui-Hui Meng department of Gastroenterology Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022Hubei ProvinceChina department of Hepatology Hubei Provincial Hospital of Traditional Chinese MedicineWuhan 430065Hubei ProvinceChina

BACKGROUND Cirrhosis is a common liver disease,and ascites is one of the common clinical ***,the clinical manifestations of ascites combined with hyponatremia as a high-risk condition and its relationship to patient prognosis have not been fully *** To explore the clinical manifestations,prognostic factors,and relationships of ascites with hyponatremia in patients with cirrhosis to provide better diagnostic and treatment *** In this study,we retrospectively analyzed the clinical data of 150 patients diagnosed with cirrhosis and ascites between 2017 and *** were divided into two groups:ascites combined with hyponatremia group and ascites *** compared the general characteristics,degree of hyponatremia,complications,treatment,and prognosis between the two *** In the study results,patients in the ascites combined with hyponatremia group showed an older average age(58.2±8.9 years),64.4%were male,and had a significantly longer hospitalization time(12.7±5.3 d).Hyponatremia was more severe in this group,with a mean serum sodium concentration of 128.5±4.3 mmol/L,which was significantly different from the ascites group of 137.6±2.1 mmol/*** with ascites and hyponatremia were more likely to develop hepatic encephalopathy(56.2%vs 39.0%),renal impairment(45.2%vs 28.6%)and infection(37.0%vs 23.4%).Regarding treatment,this group more frequently used diuretics(80.8%vs 62.3%)and salt supplements(60.3%vs 38.9%).Multiple logistic regression analysis identified older age[Odds ratio(OR)=1.06,P=0.025]and male gender(OR=1.72,P=0.020)as risk factors for hyponatremia combined with ***,patients with ascites and hyponatremia present a clear high-risk status,accompanied by severe complications and poor *** In patients with cirrhosis,ascites with hyponatremia is a high-risk condition that is often associated with severe complications.

关键词： liver cirrhosis Ascites Hyponatremia Risk Complications

ON THE ESTIMATIONS OF BOUNDS FOR DETERMINANT OF HADAMARD PRODUCT OF H-MATICES

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Journal of Computational mathematics 2001年第4期19卷 365-370页

作者： Yao-tang li (department of Mathemotics, Yuunan university, Kunming 650091, china) ji-cheng li (department of mathematics, Xian jiaotong university, Xian 71049, china) 云南大学云南昆明 650091 西安交通大学陕西西安 710049

In this paper, some estimations of bounds for determinant of Hadamard product of H-matrices are given. The main result is the following: if A= (aij) and B=(bij) are nonsingular H-matrices of order n and ∏in=1, aiibii> 0, and Ak and Bk, k = 1, 2,…,n, are the k× k leading principal submatrices of A and B, respectively, then where M(Ak) denotes the comparison mains of Ak.

关键词： H-matrix Determinant Hadamard product.

A Logarithmic Decay of the Energy for the Hyperbolic Equation with Supercritical Damping

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Journal of Partial Differential Equations 2024年第2期37卷 150-165页

作者： li Xiaolei GUO bin School of mathematics and Statistics Changchun University of Science and TechnologyChangchun 130022China School of mathematics Jilin UniversityChangchun 130012China

We are concerned with the following quasilinear wave equation involving variable sources and supercritical damping:■Generally speaking,when one tries to use the classical multiplier method to analyze tRhe asymptotic behavior of solutions,an inevitable step is to deal with the integralΩ|ut|^(m−2)utudx.A usual technique is to apply Young’s inequality and Sobolev embedding inequality to use the energy function and its derivative to control this integral for the subcritical or critical ***,for the supercritical case,the failure of the Sobolev embedding inequality makes the classical method be *** do this,our strategy is to prove the rate of the integral RΩ|u|^(m)dx grows polynomially as a positive power of time variable t and apply the modified multiplier method to obtain the energy functional decays *** results improve and extend our previous work[12].Finally,some numerical examples are also given to authenticate our results.

关键词： Energy decay estimate asymptotic behavior p(x)-Laplacian operator supercritical damping