检索结果-南通市图书馆

Chinese Journal of Chemical Engineering 2017年第9期25卷 1137-1142页

作者： S.r.mishra m.m.Bhatti Department of mathematics Siksha ‘O’ Anusandhan University Shanghai Institute of Applied mathematics and mechanics Shanghai University

In this article, we have considered the simultaneous influence of ohmic heating and chemical reaction on heat and mass transfer over a stretching sheet. The effects of applied magnetic field are also taken into consideration while the induced magnetic field is not considered due to very small magnetics reynolds number. The governing flow problem comprises of momentum, continuity, thermal energy and concentration equation which are transformed into highly nonlinear coupled ordinary differential equations by means of similarity transforms, which are then, solved numerically with the help of Successive Linearization method(SLm) and Chebyshev Spectral collocation method. Numerical values of skin friction coefficient, local Nusselt number, and Sherwood number are also taken into account with the help of tables. The physical influence of the involved parameters of flow velocity, temperature and concentration distribution is discussed and demonstrated graphically. The numerical comparison is also presented with the existing published results and found that the present results are in excellent agreement which also confirms the validity of the present methodology.

关键词： Ohmic heating Heat and mass transfer Chemical reaction Successive linearization method

Thermomagnetic viscoelastic responses in a functionally graded hollow structure

在线全文

学校读者我要写书评

暂无评论

Acta mechanica Sinica 2011年第4期27卷 567-577页

作者： m.N.m.Allam r.Tantawy mathematics Department Faculty of ScienceMansoura University

This paper presents an analytical solution for the interaction of electric potentials, electric displacements, elastic deformations, and thermoelasticity, and describes electromagnetoelastic responses and perturbation of the magnetic field vector in hollow structures （cylinder or sphere）, subjected to mechanical load and electric potential. The material properties, thermal expansion coefficient and magnetic permeability of the structure are assumed to be graded in the radial direction by a power law distribution. In the present model we consider the solution for the case of a hollow structure made of viscoelastic isotropic material, reinforced by elastic isotropic fibers, this material is considered as structurally anisotropic material. The exact solutions for stresses and perturbations of the magnetic field vector in FGm hollow structures are determined using the infinitesimal theory of magnetothermoelasticity, and then the hollow structure model with viscoelastic material is solved using the correspondence principle and Illyushin＇s approximation method. Finally, numerical results are carried out and discussed.

关键词： Functionally graded material Viscoelasticity Perturbation of magnetic field vector magnetoelasticity

INErTIAL ALGOrITHmS FOr THE STATIONArY NAVIEr-STOKES EQUATIONS

在线全文

学校读者我要写书评

暂无评论

Acta mathematica Scientia 2003年第2期23卷 219-238页

作者：侯延仁 r.m.m.mattheij College of Science Xi'an Jiaotong University Department of mathematics and Computing Science

Several kind of new numerical schemes for the stationary Navier-Stokes equations based on the virtue of Inertial manifold and Approximate Inertial manifold, which we call them inertial algorithms in this paper, together with their error estimations are presented. All these algorithms are constructed under an uniform frame, that is to construct some kind of new projections for the Sobolev space in which the true solution is sought. It is shown that the proposed inertial algorithms can greatly improve the convergence rate of the standard Galerkin approximate solution with lower computing effort. And some numerical examples are also given to verify results of this paper.

关键词： Navier-Stokes equations error estimation inertial algorithms

An improved displacement-based adaptive pushover procedure based on factor modal combination rule

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2014年第2期13卷 223-241页

作者： Abbasnia r Tajik Davoudi A maddah m.m Department of Civil Engineering Iran University of Science and Technology

An accurate estimation of the applied load pattern is an essential component in each pushover procedure. recently, a number of adaptive pushover methods have been proposed in which the effects of the higher modes as well as the progressive changes in the dynamic characteristics of structures are taken into account to compute the applied load pattern. The basic shortcoming of these advanced pushover methods is related to employing the quadratic modal combination rule, whereby the sign reversals of the modal load vectors are suppressed. In this study, an improved displacement-based adaptive pushover method is developed in which the applied load pattern is computed using the factor modal combination rule(FmC). In the proposed procedure, multiple load patterns, depending on the number of the modes considered, are determined in order to take into account the sign reversals of different modal load vectors. The accuracy of the proposed method is verifi ed for seven moment resisting frame buildings of 3, 9 and 20 stories with regularity or vertically geometric and mass irregularities subjected to 60 earthquake ground motion records. The results showed that the proposed methodology is capable of reproducing the peak dynamic responses with very good accuracy.

关键词： adaptive pushover higher modes sign reversal factor modal combination rule

Characteristics of Positive Ions in the Sheath region of magnetized Collisional Electronegative Discharges

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2014年第6期16卷 552-556页

作者： m.m.HATAmI A.r.NIKNAm Physics Department of K.N.Toosi University of Technology Laser-Plasma research Institute of Shahid Beheshti University G.C.

A hydrodynamic model is used to investigate the characteristics of positive ions in the sheath region of a low-pressure magnetized electronegative discharge. Positive ions are modeled as a cold fluid, while the electron and negative ion density distributions obey the Boltzmann distribution with two different temperatures. By taking into account the ion-neutral collision effect in the sheath region and assuming that the momentum transfer cross section has a power law dependence on the velocity of positive ions, the sheath formation criterion （modified Bohm＇s criterion） is derived and it is shown that there are specified maximum and minimum limits for the ion mach number m. Considering these two limits of m, the behaviors of electrostatic potential, charged particle density distributions and positive ion velocities in the sheath region are studied for different values of ion-neutral collision frequency.

关键词： electronegative plasma hydrodynamic model magnetized plasma sheath,Bohm's criterion

Current perspectives and the future of disease-modifying therapies in type 1 diabetes

在线全文

学校读者我要写书评

暂无评论

World Journal of Diabetes 2025年第1期16卷 12-21页

作者： Sunetra mondal Joseph m Pappachan Department of Endocrinology NRS Medical College and HospitalKolkata 700014West BengalIndia Department of Endocrinology and metabolism Lancashire Teaching Hospitals NHS TrustPreston PR29HTUnited Kingdom Faculty of Science Manchester Metropolitan UniversityManchester M156BHUnited Kingdom Department of Endocrinology Kasturba Medical CollegeManipal 576104India

Use of immunomodulating agents to prevent the progression of autoimmuneβ-cell damage leading to type 1 diabetes mellitus(T1Dm)is an interesting area for *** include non-specific anti-inflammatory agents,immunologic vaccination and anti-inflammatory agents targeting specific immune cells or *** is an anti-CD3-molecule that binds to and leads to the disappearance of the CD3/TCr complex and rendering the T cell anergic to its target *** and clinical trials have demonstrated its efficacy in reducing the decline in serum C-peptide levels and the need for insulin therapy if used early in the disease process of *** benefits have been apparent as early as six months to as long as seven years after *** has recently been approved by the Food and Drug Administration to delay the onset of clinical(stage 3)type 1 diabetes in children above 8 years of *** their recent metaanalysis published in the World Journal of Diabetes,ma et al found that those in the teplizumab treatment group have a greater likelihood of reduction in insulin use,change in C-peptide response,and better glycemic control compared to the control group with a good safety ***,all the included randomized control trials have been conducted in high-income *** cost of therapy and unknown utility of the molecule in stage 3 disease limit its widespread use.

关键词： Teplizumab Type 1 diabetes mellitus Disease modifying therapy β-cell function C-peptide Immunotherapy

Energy states of the Hulthen plus Coulomb-like potential with position-dependent mass function in external magnetic fields

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第2期27卷 234-238页

作者： m Eshghi r Sever S m Ikhdair Young researchers and Elite Club Central Tehran Branch Islamic Azad University Department of Physics Middle East Technical University Department of Physics Faculty of Science An-Najah National University Department of Electrical Engineering Near East University

We need to solve a suitable exponential form of the position-dependent mass （PDm） Schr6dinger equation with a charged particle placed in the Hulthen plus Coulomb-like potential field and under the actions of the external magnetic and Aharonov-Bohm （AB） flux fields. The bound state energies and their corresponding wave functions are calculated for the spatially-dependent mass distribution function of interest in physics. A few plots of some numerical results with respect to the energy are shown.

关键词： Schr6dinger equation Hulthen plus Coulomb-like potential position-dependent mass distributionfunctions perpendicular magnetic and Aharonov-Bohm flux fields

recognition of the Projective Special Linear Group over GF(3)

在线全文

学校读者我要写书评

暂无评论

Acta mathematica Sinica,English Series 2010年第3期26卷 477-488页

作者： m.r.DArAFSHEH School of mathematics College of Science University of Tehran

Let P be a finite group and denote by w（P） the set of its element orders. P is called k-recognizable by the set of its element orders if for any finte group G with ω（G） =ω（P） there are, up to isomorphism, k finite groups G such that G ≌P. In this paper we will prove that the group Lp（3）, where p 〉 3 is a prime number, is at most 2-recognizable.

关键词： element order projective special linear group recognition by spectrum

Electrodeless plasma thrusters for spacecraft: a review

在线全文

学校读者我要写书评

暂无评论

Plasma Science and Technology 2017年第8期19卷 1-24页

作者： S N BATHGATE m m m BILEK D r mCKENZIE Applied and Plasma Physics School of PhysicsUniversity of Sydney

The physics of electrodeless electric thrusters that use directed plasma to propel spacecraft without employing electrodes subject to plasma erosion is reviewed. Electrodeless plasma thrusters are potentially more durable than presently deployed thrusters that use electrodes such as gridded ion,Hall thrusters, arcjets and resistojets. Like other plasma thrusters, electrodeless thrusters have the advantage of reduced fuel mass compared to chemical thrusters that produce the same thrust. The status of electrodeless plasma thrusters that could be used in communications satellites and in spacecraft for interplanetary missions is examined. Electrodeless thrusters under development or planned for deployment include devices that use a rotating magnetic field; devices that use a rotating electric field; pulsed inductive devices that exploit the Lorentz force on an induced current loop in a plasma; devices that use radiofrequency fields to heat plasmas and have magnetic nozzles to accelerate the hot plasma and other devices that exploit the Lorentz force. Using metrics of specific impulse and thrust efficiency, we find that the most promising designs are those that use Lorentz forces directly to expel plasma and those that use magnetic nozzles to accelerate plasma.

关键词： spacecraft a review propellant Lorentz thrust rotating radiofrequency erosion presently exploit

Swelling-induced finite bending of functionally graded pH-responsive hydrogels:a semi-analytical method

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2019年第5期40卷 679-694页

作者： m.SHOJAEIFArD m.r.BAYAT m.BAGHANI School of mechanical Engineering College of Engineering University of Tehran

recently, pH-sensitive hydrogels have been utilized in the diverse applications including sensors, switches, and actuators. In order to have continuous stress and deformation ?elds, a new semi-analytical approach is developed to predict the swelling induced?nite bending for a functionally graded(FG) layer composed of a pH-sensitive hydrogel,in which the cross-link density is continuously distributed along the thickness direction under the plane strain condition. Without considering the intermediary virtual reference,the initial state is mapped into the deformed con?guration in a circular shape by utilizing a total deformation gradient tensor stemming from the inhomogeneous swelling of an FG layer in response to the variation of the pH value of the solvent. To enlighten the capability of the presented analytical method, the ?nite element method(FEm) is used to verify the accuracy of the analytical results in some case studies. The perfect agreement con-?rms the accuracy of the presented method. Due to the applicability of FG pH-sensitive hydrogels, some design factors such as the semi-angle, the bending curvature, the aspect ratio, and the distributions of deformation and stress ?elds are studied. Furthermore, the tangential free-stress axes are illustrated in deformed con?guration.

关键词： pH-sensitive hydrogel functionally graded(FG)layer finite bending semianalytical solution finite element method(FEm)