检索结果-南通市图书馆

同方期刊数据库

Mechanical and thermal postbuckling of FGM thick circular cylindrical shells reinforced by FGM stiffener system using higher-order shear deformation theory

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2017年第1期38卷 73-98页

作者： d.V.dUNG h.T.ThIEM Faculty of Mathematics Mechanics and InformaticsVietnam National UniversityHanoi 100000Vietnam

The postbuckling of the eccentrically stiffened circular cylindrical shells made of functionally graded materials （FGMs）, subjected to the axial compressive load and external uniform pressure and filled inside by the elastic foundations in the thermal environments, is investigated with an analytical method. The shells are reinforced by FGM stringers and rings. The thermal elements of the shells and stiffeners in the fundamental equations are considered. The equilibrium and nonlinear stability equations in terms of the displacement components for the stiffened shells are derived with the third-order shear deformation theory and Leckhniskii smeared stiffener technique. The closed-form expressions for determining the buckling load and postbuckling load-deflection curves are obtained with the Galerkin method. The effects of the stiffeners, the foundations, the material and dimensional parameters, and the pre-existent axial compressive and thermal load are considered.

关键词： stiffened cylindrical shell functionally graded material (FGM) postbuck- ling elastic foundation analytical

Modified Joint distribution of Wave heights and Periods

在线全文

学校读者我要写书评

暂无评论

China Ocean Engineering 2016年第3期30卷 359-374页

作者： h.d.Zhang C.Guedes Soares Centre for Marine Technology and Ocean Engineering (CENTEC) Instituto Superior Técnico Universidade de Lisboa

The modified versions of the linear theoretical model of Longuet-higgins （1983） are derived in this work and also compared with the laboratory experiments carried out in MAR1NTEK. The main feature of modifications is to replace the mean frequency in the formulation with the peak frequency of the wave spectrum. These two alternative forms of joint distributions are checked in three typical random sea states characterized by the initial wave steepness. In order to further explore the properties ＆these models, the associated marginal distributions of wave heights and wave periods are also researched with the observed statistics and some encouraging results are obtained.

关键词： Longuet-higgins joint distribution mixed sea state nonlinear wave series wave height wave period

在线全文

学校读者我要写书评

暂无评论

无机合成

无机合成

作者： d.h.·布希(d.h. Busch)

Analytical investigation of Jeffery-hamel flow with high magnetic field and nanoparticle by Adomian decomposition method

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2012年第1期33卷 25-36页

作者： M.ShEIKhOLESLAMI d.d.GANJI h.R.AShORYNEJAd.h.B.ROKNI Faculty of Mechanical Engineering Babol University of TechnologyP.O.Box 484BabolIslamic Republic of Iran

In this study, the effects of magnetic field and nanoparticle on the Jeffery- hamel flow are studied using a powerful analytical method called the Adomian decomposition method （AdM）. The traditional Navier-Stokes equation of fluid mechanics and Maxwell＇s electromagnetism governing equations are reduced to nonlinear ordinary differential equations to model the problem. The obtained results are well agreed with that of the Runge-Kutta method. The present plots confirm that the method.h.s high accuracy for different a, ha, and Re numbers. The flow field inside the divergent channel is studied for various values of hartmann ：number and angle of channel. The effect of nanoparticle volume fraction in the absence of magnetic field is investigated.

关键词： magnetohydrodynamic Jeffery-hamel flow Adomian decomposition method nonlinear ordinary differential equation nanofluid

decoupling coefficients of dilatational wave for Biot's dynamic equation and its Green's functions in frequency domain

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2016年第1期37卷 121-136页

作者： Boyang dING A.h.d.ChENG Zhanglong ChEN City College Zhejiang University department of Civil Engineering Zhejiang University of Technology College of Civil Engineering and Architecture University of Mississippi

Green＇s functions for Blot＇s dynamic equation in the frequency domain can be a highly useful tool for the investigation of dynamic responses of a saturated porous medium. Its applications are found in soil dynamics, seismology, earthquake engineering, rock mechanics, geophysics, and acoustics. however, the mathematical work for deriving it can be daunting. Green＇s functions have been presented utilizing an analogy between the dynamic thermoelasticity and the dynamic poroelasticity in the frequency domain using the u-p formulation. In this work, a special term ＂decoupling coefficient＂ for the decomposition of the fast and slow dilatational waves is proposed and expressed to present a new methodology for deriving the poroelastodynamic Green＇s functions. The correct- ness of the solution is demonstrated by numerically comparing the current solution with Cheng＇s previous solution. The separation of the two waves in the present methodology allows the more accurate evaluation of Green＇s functions, particularly the solution of the slow dilatational wave. This can be advantageous for the numerical implementation of the boundary element method （BEM） and other applications.

关键词： decoupling coefficient dilatational wave Biot's equation poroelastodynamic Green's function frequency domain

在线全文

学校读者我要写书评

暂无评论

工程项目经济评价入门

工程项目经济评价入门

作者： d.h.·艾伦(d.h. Allen)

学校读者我要写书评

暂无评论

儿子与情人

儿子与情人

作者： d.h.·劳伦斯(d.h. Lawrence)

Evaluation of effects of 1,3-dinitrobenzene on sperm motility of hamster using computer assisted semen analysis (CASA)

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2001年第2期3卷 109-114页

作者： L.d.C.Peiris h.d.M.Moore dept. of Zoology University of Colombo Colombo 03 Sri LankaDept. of Molecular Biology and Biotechnology University of Sheffield Sheffield S 10 2TN UK

Aim: To evaluate the effects of 1,3-dinitrobenznene (mdNB) on sperm motility of hamster and to correlate the re-sults with the fertility. Methods: Adult male hamsters were gavaged with one of the 3 dose regimes of mdNB(1.5 mg daily for 4 weeks ,1.5 mg one day a week for 4 weeks and 1.0 mg 3 days a week for 4 weeks). Computerassisted semen analysis (CASA) was used to analyse the sperm motility parameters, curvilinear velocity (VCL) andstraight line velocity (VSL) of sperm in distal corpus epididymides and distal cauda epididymides. In vitro fertilisationwas carried out only for 1.5 mg mdNB daily group to determine the sperm fertilising capacity. Results: There wasa significant reduction in sperm velocity parameters at weeks 3 and 4 after treatment, which was correlated with a de-cline in sperm fertility. Conclusion; Sperm velocity parameters may be used to determine the effect of a toxic insulton the sperm function.

关键词： mdNB sperm motility CASA sperm fertility

在线全文

学校读者我要写书评

暂无评论

中国农业的发展

中国农业的发展

作者： d.h.·珀金斯(d.h. Perkins)