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Fast and Accurate Predictor-Corrector Methods Using Feedback-Accelerated Picard Iteration for Strongly nonlinear Problems

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 1263-1294页

作者： xuechuan Wang Wei He Haoyang feng Satya n.Atluri School of Astronautics Northwestern Polytechnical UniversityXi’an710072China Department of Mechanical Engineering Texas Tech UniversityLubbock79409USA

Although predictor-corrector methods have been extensively applied,they might not meet the requirements of practical applications and engineering tasks,particularly when high accuracy and efficiency are necessary.A novel class of correctors based on feedback-accelerated Picard iteration(FAPI)is proposed to further enhance computational *** optimal feedback terms that do not require inversion of matrices,significantly faster convergence speed and higher numerical accuracy are achieved by these correctors compared with their counterparts;however,the computational complexities are comparably *** advantages enable nonlinear engineering problems to be solved quickly and accurately,even with rough initial guesses from elementary *** proposed method offers flexibility,enabling the use of the generated correctors for either bulk processing of collocation nodes in a domain or successive corrections of a single node in a finite difference *** our method,the functional formulas of FAPI are discretized into numerical forms using the collocation *** collocated iteration formulas can directly solve nonlinear problems,but they may require significant computational resources because of the manipulation of *** address this,the collocated iteration formulas are further converted into finite difference forms,enabling the design of lightweight predictor-corrector algorithms for real-time *** generality of the proposed method is illustrated by deriving new correctors for three commonly employed finite-difference approaches:the modified Euler approach,the Adams-Bashforth-Moulton approach,and the implicit Runge-Kutta ***,the updated approaches are tested in solving strongly nonlinear problems,including the Matthieu equation,the Duffing equation,and the low-earth-orbit tracking *** numerical findings confirm the computational accuracy and efficiency of the derived predictor-correc

关键词： Predictor-corrector method feedback-accelerated Picard iteration nonlinear dynamical system real-time computation

Coke behavior with H_(2)O in a hydrogen-enriched blast furnace:A review

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International Journal of Minerals,Metallurgy and Materials 2024年第5期31卷 959-976页

作者： feng Zhou Daosheng Peng Kejiang Li Alberto n.Conejo Haotian Liao Zixin xiong Dongtao Li Jianliang Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China School of Chemical Engineering The University of QueenslandSt LuciaQLD 4072Australia Baosteel Central Research Institute(R&D Center of Wuhan Iron&Steel Co. Ltd.)Wuhan 430080China Shougang Research Institute of Technology Shougang Group Corporation Ltd.Beijing 100043China Beijing Key Laboratory of Green Recyclable Process for Iron and Steel Production Technology Beijing 100043China

Hydrogen-enriched blast furnace ironmaking has become an essential route to reduce CO_(2)emissions in the ironmaking ***,hydrogen-enriched reduction produces large amounts of H_(2)O,which places new demands on coke quality in a blast *** a hydrogen-rich blast furnace,the presence of H_(2)O promotes the solution loss *** result improves the reactivity of coke,which is 20%-30%higher in a pure H_(2)O atmosphere than in a pure CO_(2)*** activation energy range is 110-300 kJ/mol between coke and CO_(2)and 80-170 kJ/mol between coke and H_(2)***_(2)and H_(2)O are shown to have different effects on coke degradation *** review provides a comprehensive overview of the effect of H_(2)O on the structure and properties of *** exploring the interactions between H_(2)O and coke,several unresolved issues in the field requiring further research were *** review aims to provide valuable insights into coke behavior in hydrogen-rich environments and promote the further development of hydrogen-rich blast furnace ironmaking processes.

关键词： hydrogen ironmaking coke behavior blast furnace gasification microstructure kinetics

Design and identification of a double-acting piezoelectric-hydraulic hybrid actuator

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Chinese Journal of Aeronautics 2024年第3期37卷 456-467页

作者： Junjian ZHAnG Zhihua feng Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes University of Science and Technology of ChinaHefei 230026China

Traditional single-acting piezoelectric-hydraulic hybrid actuators usually have the problem of inertial force caused by flow pulsation of the liquid,which degrades their output *** suppress or solve the associated inertial force and enhance its output capabilities,this paper proposes a new type of double-acting piezoelectric-hydraulic hybrid actuator with four check valves acting as mechanical *** new hybrid actuator was fabricated and its output performance was *** the voltage is 700 Vp-pand the bias pressure is 2 MPa,the pulsation ratesδof the new actuator at 400 Hz,500 Hz and 600 Hz are 2.29,2.08 and 1.78,respectively,whileδof the single-acting hybrid actuator under the same conditions are 10.98,11.05 and ***,the liquid pulsation rate of the new hybrid actuator is significantly reduced,which is beneficial for improving the flow uniformity and weakening the influence of inertial force on the hybrid *** strategy ultimately leads to a maximum no-load velocity of 168.1 mm/s at 600 Hz and a maximum blocking force of 141 n at 450 Hz for the new hybrid *** addition,this strategy has the potential to be used in other electrohydrostatic actuators to improve their performance.

关键词： Double-acting Flow pulsation Inertial force Piezoelectric actuators Piezoelectric devices Piezoelectric hydraulic actuation Piezoelectric pump

Rational Solutions of First Order Algebraic Ordinary Differential Equations

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Journal of Systems Science & Complexity 2024年第2期37卷 567-580页

作者： feng Shuang SHEn Liyong School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

Let f(t,y,y')=∑ _(i=0)^(n )a_(i)(t,y)y'^(i)=0 be an irreducible first order ordinary differential equation with polynomial *** in 1998 proved that there exists a constant C such that every rational solution of f(t,y,y')=0 is of degree not greater than *** show that this degree bound C depends not only on the degrees of f in t,y,y' but also on the coefficients of f viewed as the polynomial in t,y,y'.In this paper,the authors show that if f satisfies deg(f,y)n max i=0{deg(a_(i),y)−2(n−i)}>0,then the degree bound C only depends on the degrees of f in t,y,y',and furthermore we present an explicit expression for C in terms of the degrees of f in t,y,y'.

关键词： Degree bound first order AODE height rational solution

Frequency Domain Fatigue Evaluation on SCR Girth-Weld Based on Structural Stress

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China Ocean Engineering 2024年第2期38卷 255-270页

作者： ZHAnG Long ZHAO Tian-feng College of Safety and Ocean Engineering China University of Petroleum(Beijing)Beijing 102249China

The Steel Catenary Riser(SCR)is a vital component for transporting oil and gas from the seabed to the floating *** harsh environmental conditions and complex platform motion make the SCR’s girth-weld prone to fatigue *** structural stress fatigue theory and Master S-n curve method provide accurate predictions for the fatigue damage on the welded joints,which demonstrate significant potential and compatibility in multi-axial and random fatigue ***,we propose a new frequency fatigue model subjected to welded joints of SCR under multiaxial stress,which fully integrates the mesh-insensitive structural stress and frequency domain random process and transforms the conventional welding fatigue technique of SCR into a spectrum analysis technique utilizing structural ***,a full-scale FE model of SCR with welds is established to obtain the modal structural stress of the girth weld and the frequency response function(FRF)of modal coordinate,and a biaxial fatigue evaluation about the girth weld of the SCR can be achieved by taking the effects of multi-load correlation and pipe-soil interaction into *** research results indicate that the frequency-domain fatigue results are aligned with the time-domain results,meeting the fatigue evaluation requirements of the SCR.

关键词： SCR girth weld random vibration self(cross)power spectrum structural stress method biaxial fatigue damage

Hydrophobic long-chain two-dimensional perovskite scintillators for underwater x-ray imaging

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Rare Metals 2024年第1期43卷 175-185页

作者： Jin-xiao Zheng Zi-An Zhou Tiao feng Hui Li Cheng-Hua Sun nüWang Yang Tian Yong Zhao Shu-Yun Zhou Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Laboratory of Bioinspired Smart Interfacial Science and Technology of the Ministry of Education Beijing Key Laboratory of Bioinspired Energy Materials and DevicesSchool of ChemistryBeijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijing 100191China Department of Engineering Physics Tsinghua University and Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China e-mail:yangt@***

The underwater x-ray imaging technology development is significant to subaqueous target reconnaissance/detection/identification, subfluvial archaeology,submerged resource exploration, etc. As the core of x-ray imaging detection, the scintillator has been plagued by inherent moisture absorption and decomposition, and strict requirements for seamless packaging and ***, we designed a manganese-doped two-dimensional(2D) perovskite scintillator modified by hydrophobic longchain organic amine through the combination of component and doping engineering. The modified perovskites show high water repellency that can be used as an underwater x-ray scintillator. x-ray images of aquatic organisms or other objects with a high spatial resolution of10 lp·mm^(-1) at a big view field(32 mm × 32 mm) were obtained by scintillation screen. This hydrophobic perovskite scintillator based on molecular design is of great promise in underwater x-ray nondestructive testing technology development.

关键词： Two-dimensional perovskite Hydrophobic Scintillators Underwater x-ray imaging Underwater nondestructive testing technology

Higher-order expansions of powered extremes of logarithmic general error distribution

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Applied Mathematics(A Journal of Chinese Universities) 2024年第1期39卷 47-54页

作者： TAn xiao-feng LI Li-hui School of Mathematics and Statistics Southwest UniversityChongqing 400715China

In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥***-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing *** is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v).

关键词： logarithmic general error distribution convergence rate higher-order expansion powered ex-treme

Sequence [2,3]-Sigmatropic Rearrangement: One-Pot Synthesis of Proparggyl Allenylamines

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Chinese Journal of Chemistry 2024年第18期42卷 2223-2227页

作者： Huihui feng Yujuan xie Lliang Huang Yongqing xu Junhai Huang Huangdi feng College of Chemistry and Chemical Engineering Shanghai University of Engineering ScienceShanghai 201620China Shanghai Frontiers Science Research Centerfor Druggability of Cardiovascular noncoding RnA Institute for Frontier Medical Technology Shanghai Universityof Engineering ScienceShanghai 201620China

Allenes,served as highly sought-after building blocks,are an indispensable component of synthetic *** utility in modulating the chemical,physical,and pharmaceutical properties of organic compounds make allenes a desirable choice in various ***,we report a facile method for the atom-economical synthesis of propargyl allenylamines via an underdeveloped[2,3]-sigmatropic *** strategy employs easily accessible propargylamines as starting materials,which are first converted into propargyl ammonium salts,followed by a base-promoted[2,3]-sigmatropic *** one-pot,two-step reaction proceeds in the absence of transition metals,displays a very broad scope,and does not require the introduction of the electron-withdrawing group into the starting materials.

关键词： Allene Propargylamine C-n activation Sigmatropic rearrangement Metal-free Synthetic methods Domino reactions

Photodegradation of xylene isomers:Kinetics,mechanism,secondary pollutant formation potential and health risk evaluation

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Journal of Environmental Sciences 2024年第2期136卷 658-669页

作者： xiaoyan Chen Weikun Zhu Sufen feng Jiangyao Chen Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Photodegradation technology has been widely applied in the purification of industrial aromatic ***,whether this technology efficiently removes the pollutants to prevent secondary pollution and health risk is still ***,the photodegradation processes of three xylenes were compared under designed reaction atmospheres and light *** lamp showed poor photodegradation ability toward xylenes,no matter in n_(2) or n_(2)+O_(2)system,while much higher photodegradation performance of xylenes were obtained under ultraviolet(UV)and vacuum ultraviolet(VUV)irradiation,especially in n_(2)+O_(2)+VUV system,where 97.9%of m-xylene,99.0%of o-xylene or 87.5%of p-xylene with the initial concentration of 860 mg/m^(3) was removed within 240 *** xylenes underwent three processes of photo-isomerization,photodecomposition and photo-oxidation to produce intermediates of aromatics,alkanes and *** them,the photo-isomerization products showed the highest concentration percentage(e.g.,≥50%in o-xylene system),confirming that photo-isomerization reaction was the dominated photodegradation process of ***,these isomerized products not only contributed about 97%and91%to the formation potential of O3(OFP)and secondary organic aerosols(SOAFP),but also displayed obvious non-carcinogenic risk,although one of photodecomposition product—benzene showed the highest occupational exposure ***,the secondary pollution and health risks of photodegradation products of xylenes were non-ignorable,although the OFP,SOAFP and health risks of the generated products reduced at least 4.5 times in comparison with that of the degraded *** findings are helpful for the appropriate application of this technology in the purification of industrial organic waste gas.

关键词： Isomer aromatics Photodegradation Ozone formation Secondary organic aerosols Health risk