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Applied Mathematics and Mechanics(English Edition) 2014年第1期35卷 85-96页

作者： I.M.stamovA t.g.stamov Department of Mathematics The University of Texas at San Antonio Department of Engineering Design Faculty of Mechanical EngineeringTechnical University of Sofia

Sufficient conditions are investigated for the global stability of the solu tions to models based on nonlinear impulsive differential equations with ＂supremum＂ and variable impulsive perturbations. the main tools are the Lyapunov functions and Razu mikhin technique. two illustrative examples are given to demonstrate the effectiveness of the obtained results.

关键词： global stability Lyapunov-Razumikhin function nonlinear impulsive dif-ferential equation with "supremum" variable impulsive perturbation

transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN t.ASgHAR Z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

this paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. the influence of magnetic fields is also inspected in terms of their physical characteristics. to depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).the effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： hybrid nanofluid oscillating curved stretchable sheet gyrotactic microorganism Cattaneo-Christov heat and mass flux chemical reaction analytical solution O368

Breather solutions of modified Benjamin-Bona-Mahony equation

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Chinese Physics B 2021年第2期30卷 220-226页

作者： g t Adamashvili technical University of georgia Kostava Street 77Tbilisi0179Georgia

New two-component vector breather solution of the modified Benjamin-Bona-Mahony(MBBM)equation is *** the generalized perturbation reduction method,the MBBM equation is reduced to the coupled nonlinear Schr¨odinger equations for auxiliary *** analytical expressions for the profile and parameters of the vector breather oscillating with the sum and difference of the frequencies and wavenumbers are *** two-component vector breather and single-component scalar breather of the MBBM equation is compared.

关键词： modified Benjamin-Bona-Mahony equation generalized perturbation reduction method vector breather nonlinear waves

the impact of alpha-fetoprotein (AFP), child-turcotte-pugh (CtP) score and disease staging on the survival of hepatocellular carcinoma (HCC) patients: a retrospective cohort from single oncology center

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Oncology research 2025年第1期33卷 149-160页

作者： Nasser Mulla Yousef Katib Asim M Almughamsi Duaa S Alkhayat Mohamed Mosaad Samir t Alfotih Rawan Alaofi Department of Internal Medicine Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Radiology Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Surgery Faculty of Medicine Taibah University Madinah 42278 Saudi Arabia. Department of Endemic and Infectious Diseases Suez Canal University Ismailia 41522 Egypt. King Salman bin Abdulaziz Medical City Madinah 42311 Saudi Arabia. Prince Mohammed Bin Abdulaziz Hospital Madinah 41511 Saudi Arabia.

Background:Hepatocellular carcinoma (HCC) is the most common cause of cancer-related death in Saudi Arabia. Our study aimed to investigate the patterns of HCC and the effect of tNM staging, Alfa-fetoprotein (AFP), and Child-turcotte Pugh (CtP) on patients' overall survival (OS).Methods:A retrospective analysis was conducted on 43 HCC patients at a single oncology center in Saudi Arabia from 2015 to 2020. All patients had to fulfill one of the following criteria: (a) a liver lesion reported as definitive HCC on dynamic imaging and/or (b) a biopsy-confirmed diagnosis.Results:the mean patient age of all HCC cases was 66.8 with a male-to-female ratio of 3.3:1. All patients were stratified into two groups: viral HCC (n = 22, 51%) and non-viral HCC (n = 21, 49%). Among viral-HCC patients, 55% were due to HBV and 45% due to HCV. Cirrhosis was diagnosed in 79% of cases. Age and sex did not significantly statistically differ in OS among viral and non-viral HCC patients (-value > 0.05). About 65% of patients had tumor size >5 cm during the diagnosis, with a significant statistical difference in OS (-value = 0.027). AFP was >400 ng/ml in 45% of the patients. there was a statistically significant difference in the OS in terms of AFP levels (-value = 0.021). A statistically significant difference was also observed between the CtP score and OS (-value = 0.02). CtP class B had the longest survival. BSC was the most common treatment provided to HCC patients followed by sorafenib therapy. there was a significant statistical difference in OS among viral and non-viral HCC patients (-value = 0.008).Conclusions:the most common predictors for OS were the underlying cause of HCC, AFP, and tumor size. Being having non-viral etiology, a tumor size >5 cm, an AFP > 400 ng/mL, and a CtP score class C were all negatively associated with OS.

关键词： Alpha-fetoprotein (AFP) Child-turcotte-pugh Hepatocellular carcinoma Pattern Progression free survival

Performance Analysis of Intelligent Robust Facility Layout Design

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 407-418页

作者： g MOSLEMIPOUR t S LEE Y t LOONg Department of Industrial Engineering Payame Noor University Faculty of Engineering and technology Multimedia University

Design of a robust production facility layout with minimum handling cost （MHC） presents an appropriate approach to tackle facility layout problems in a dynamic volatile environment, in which product demands randomly change in each planning period. the objective of the design is to find the robust facility layout with minimum total material handling cost over the entire multiperiod planning horizon. this paper proposes a new mathematical model for designing robust machine layout in the stochastic dynamic environment of manufacturing systems using quadratic assignment problem （QAP） formulation. In this investigation, product demands are assumed to be normally distributed random variables with known expected value, variance, and covariance that randomly change from period to period. the proposed model was verified and validated using randomly generated numerical data and benchmark examples. the effect of dependent product demands and varying interest rate on the total cost function of the proposed model has also been investigated. Sensitivity analysis on the proposed model has been performed. Dynamic programming and simulated annealing optimization algorithms were used in solving the modeled example problems.

关键词： Robust layout Dynamic stochastic environment Manufacturing system Dynamic programming

Almost Everywhere Convergence of Fejér Means of L^1 Functions on Rarely Unbounded Vilenkin groups

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Acta Mathematica Sinica,English Series 2007年第12期23卷 2269-2294页

作者： gyrgy gt College of Nyíregyháza Institute of Mathematics and Computer Science

A highly celebrated problem in dyadic harmonic analysis is the pointwise convergence of the Fejér （or （C, 1）） means of functions on unbounded Vilenkin groups. there are several papers of the author of this paper concerning this. that is, we know the a.e. convergence σnf → f （n → ∞） for functions f ∈ L^p, where p 〉 1 （Journal of Approximation theory, 101（1）, 1-36, （1999）） and also the a.e. convergence σMnf → f （n → ∞） for functions f ∈ L^1 （Journal of Approximation theory, 124（1）, 25-43, （2003））. the aim of this paper is to prove the a.e. relation limn→∞ σnf = f for each integrable function f on any rarely unbounded Vilenkin group. the concept of the rarely unbounded Vilenkin group is discussed in the paper. Basically, it means that the generating sequence m may be an unbounded one, but its ＂big elements＂ are not ＂too dense＂.

关键词： rarely unbounded Vilenkin groups Vilenkin series Fejér means a.e. convergence

Almost Everywhere Convergence of Sequences of Cesàro and Riesz Means of Integrable Functions with Respect to the Multidimensional Walsh System

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Acta Mathematica Sinica,English Series 2014年第2期30卷 311-322页

作者： gyrgy gt Institute of Mathematics and Computer Science College of Nyíregyhza

the aim of this paper is to prove the *** of sequences of the Cesaro and Riesz means of the Walsh–Fourier series of d variable integrable *** is,let a=（a1,...,ad）：N→Nd（d∈P）such that aj（n＋1）≥δsupk≤n aj（k）（j=1,...,d,n∈N）for someδ〉0 and a1（＋∞）=···=ad（＋∞）=＋∞.then,for each integrable function f∈L1（Id）,we have the *** for the Cesaro means limn→∞σαa（n）f=f and for the Riesz means limn→∞σα,γa（n）f=f for any 0〈αj≤1≤γj（j=1,...,d）.A straightforward consequence of our result is the so-called cone restricted *** of the multidimensional Cesaro and Riesz means of integrable functions,which was proved earlier by Weisz.

关键词： Walsh system d-dimensional Fejer and Riesz means subsequence almost everywhereconvergence

Development and testing of Aluminum Micro Channel Heat Sink

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Journal of thermal Science 2010年第3期19卷 245-252页

作者： g.Kumaraguruparan t.Sornakumar Department of Mechanical Engineering Thiagarajar College of EngineeringMadurai-625015India

Microchannel heat sinks constitute an innovative cooling technology for the removal of a large amount of heat from a small area and are suitable for electronics *** the present work,tool Steel D2 grade milling slitting saw type plain milling cutter is fabricated the microchannels are machined in aluminum work pieces to form the microchannel heat sink using the fabricated milling cutter in an horizontal milling machine.A new experimental set-up is fabricated to conduct the tests on the microchannel heat *** heat carried by the water increases with mass flow rate and heat *** heat transfer coefficient and Nusselt number increases with mass flow rate and increased heat *** pressure drop increases with Reynolds number and decreases with input *** friction factor decreases with Reynolds number and decreases with input *** thermal resistance decreases with pumping power and decreases with input heat.

关键词： Microchannel heat transfer pressure drop friction factor heat transfer coefficient.

Uniform and L-convergence of Logarithmic Means of Walsh-Fourier Series

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Acta Mathematica Sinica,English Series 2006年第2期22卷 497-506页

作者： g.gát U.gOgINAVA Institute of Mathematics and Computer Science College of Nyiregyhaza Department of Mechanics and Mathematics Tbilisi State University

the （NSrlund） logarithmic means of the Fourier series of the integrable function f is：1/lnn-1∑k=1Sk（f）/n-k, where ln：=n-1∑k=11/k.In this paper we discuss some convergence and divergence properties of this logarithmic means of the Walsh-Fourier series of functions in the uniform, and in the L^1 Lebesgue norm. Among others, as an application of our divergence results we give a negative answer to a question of Móricz concerning the convergence of logarithmic means in norm.

关键词： Walsh system Norlund logarithmic means Convergence divergence properties

Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-tALOOKOLAEI H.gHANDVAR E.JUMAEV S.KHAtIR t.CUONg-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and technology Solutions Ho Chi Minh City Open University

this paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FgP) materials. the strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. the curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. the accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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