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Applied Mathematics and Mechanics(English Edition) 2019年第9期40卷 1285-1300页

作者： M. MADHU n. S. SHASHIKumAR B. MAHAnTHESH B. j. GIREESHA n. KISHAn Department of Studies and Research in Mathematics Kuvempu University Shankaraghatta 577451 India Department of Mathematics Christ Deemed to be University Bangalore 560029 India Department of Mathematics Osmania University Telangana 500007 India

The entropy generation and heat transfer characteristics of magnetohydrodynamic (MHD) third-grade fluid flow through a vertical porous microchannel with a convective boundary condition are analyzed. Entropy generation due to flow of MHD non-newtonian third-grade fluid within a microchannel and temperature-dependent viscosity is studied using the entropy generation rate and Vogel's model. The equations describing flow and heat transport along with boundary conditions are first made dimensionless using proper non-dimensional transformations and then solved numerically via the finite element method (FEM). An appropriate comparison is made with the previously published results in the literature as a limiting case of the considered problem. The comparison confirms excellent agreement. The effects of the Grashof number, the Hartmann number, the Biot number, the exponential space-and thermal-dependent heat source (ESHS/THS) parameters, and the viscous dissipation parameter on the temperature and velocity are studied and presented graphically. The entropy generation and the Bej.n number are also calculated. From the comprehensive parametric study, it is recognized that the production of entropy can be improved with convective heating and viscous dissipation aspects. It is also found that the ESHS aspect dominates the THS aspect.

关键词： microchannel entropy generation Bej.n number third-grade fluid magnetic field

Medium Range Prediction of Summer Monsoon Activities over India vis-a-vis Their Correspondence with the Observational Features

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Advances in Atmospheric Sciences 1999年第1期16卷 135-148页

作者： Swati Basu K. j. Ramesh Z. n. Begum national Centre for Medium Range Weather Forecasting (nCMRWF) Department of Science and Technology New Delhi India

A detailed examination on various aspects of the southwest monsoon over the Indian subcontinent using analyses and forecasts of the nCMRWF global data assimilation and forecast system for the years 1994 and 1996 is carried out in this study. Obj.ctive procedures developed by Ramesh et al. (1996) based on the monsoon 1995 data are employed in the present work. It is found that all the deterministic features of the summer monsoon viz., the onset, its advancement, stagnation/revival and the withdrawal, can reasonably by prognosticated after employing the obj.ctive methodologies and monitoring daily variations of certain derived quantities from the large scale analyses and forecasts. Further, a good correspondence of the observed large scale/synoptic scale circulation features and the observed rainfall etc. with the deterministic characteristics of the summer monsoon show a good prospect for real time prognosis of the important summer monsoon activities over the Indian subcontinent.

关键词： Summer monsoon Obj.ctive procedure Onset Advancement Withdrawal

LASER HEAT TREATInG RESEARCH OF THREE KInDS OF HIGH SPEED STEEL

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Acta Metallurgica Sinica(English Letters) 1999年第5期12卷 757-760页

作者： Liu, W.n. Fang, M.n. Xing, j. Liu, Y.W. Changchun Inst of Optics and Fine Mechanics Changchun China

After laser quenching and tempering of three kinds of annealed tool high-speed steel(W18Cr-4V, W9Mo3Cr4V1, W6Mo5Cr4V2) test samples, the microhardness measurer was used to test the samples and some problems, such as the hardness and depth of hardening-quenching layer were analyzed. Furthermore, after laser quenching and tempering of the quenched and three-time tempered high-speed steel (W18Cr4V) and its hardness analyzing, different results of laser-quenching samples were obtained under different initial heat-treating.

关键词： Hardening Heat treatment Laser beam effects Microhardness Phase transitions Quenching

Hysteresis loop behaviors of ferroelectric thin films: A Monte Carlo simulation study

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Chinese Physics B 2015年第11期24卷 492-496页

作者： C.M.Bedoya-Hincapié H.H.Ortiz-varez E.Restrepo-parra j.j.Olaya-Flrez j.E.Alfonso PCM Computational Applications Universidad Nacional de Colombia Univesidad Santo Tomás Universidad de Caldas AFIS Análisis de Fallas Integridad y Superficies Universidad Nacional de Colombia Grupo de Ciencia de Materialesy superficies Departamento de Física Universidad Nacional de Colombia

The ferroelectric response of bismuth titanate Bi4Ti3O12 （BIT） thin film is studied through a Monte Carlo simulation of hysteresis loops. The ferroelectric system is described by using a Diffour Hamiltonian with three terms： the electric field applied in the z direction, the nearest dipole-dipole interaction in the transversal （x-y） direction, and the nearest dipole-dipole interaction in the direction perpendicular to the thin film （the z axis）. In the sample construction, we take into consideration the dipole orientations of the monoclinic and orthorhombic structures that can appear in BIT at low temperature in the ferroelectric state. The effects of temperature, stress, and the concentration of pinned dipole defects are assessed by using the hysteresis loops. The results indicate the changes in the hysteresis area with temperature and stress, and the asymmetric hysteresis loops exhibit evidence of the imprint failure mechanism with the emergence of pinned dipolar defects. The simulated shift in the hysteresis loops conforms to the experimental ferroelectric response.

关键词： ferroelectrics bismuth titanate hysteresis loop dipolar defects

Coercivity Enhancement of nd-Fe-B Thin Film Magnets through Dy Surface Diffusion Process

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j.urnal of Materials Science & Technology 2011年第9期27卷 826-830页

作者： C.Y. You j. Zhu n. Tian Z.X. Lu State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Xi＇an University of Technology Xi＇an 710048 China

The Dy capping layer was deposited at different temperatures on the nd-Fe-B thin films to investigate the mechanism of the coercivity enhancement through the Dy surface diffusion. The highest coercivity of 2005 kA/m （25.2 kOe） was obtained at the Dy deposition temperature of 460℃, which was significantly higher than the value of 1297 kA/m （16.3 kOe） without Dy capping layer. By performing the transmission electron microscopy （TEM） analysis, it was found that some of the grain boundaries were enriched with nd element, which could be partly ascribed to the promotion by the Dy surface diffusion. In comparison to the evolution of the spin reorientation temperature of nd2Fe14B phase after the deposition of the Dy capping layer, it is concluded that structural modification plays a significant role in the coercivity enhancement due to the Dy surface diffusion.

关键词： nd-Fe-B thin film Coercivity enhancement Dy layer Microstructure

Convergence of Hybrid Steepest-Descent Methods for Generalized Variational Inequalities

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Acta Mathematica Sinica,English Series 2006年第1期22卷 1-12页

作者： Liu Chuan ZEnG n. C. Wong j. C. YAO Department of Mathematics Shanghai Normal University Shanghai 200234 P. R. China Department of Applied Mathematics National Sun Yat-sen University Kaohsiung Taiwan 804

In this paper, we consider the generalized variational inequality GVI（F, g, C）, where F and g are mappings from a Hilbert space into itself and C is the fixed point set of a nonexpansive mapping. We propose two iterative algorithms to find approximate solutions of the GVI（F,g, C）. Strong convergence results are established and applications to constrained generalized pseudo-inverse are included.

关键词： iterative algorithms hybrid steepest-descent methods nonexpansive mappings Hilbert space Constrained generalized pseudo-inverse

Geomorphic evidence of ancient catastrophic flow type landslides in the mid-mountain ridges of the Western Flysch Carpathian Mountains(Czech Republic)

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International j.urnal of Sediment Research 2009年第1期24卷 88-98页

作者： T. PnEK j. HRADECKY K. ILHn Assoc. University of Ostrava Faculty of Science Department of Physical Geography and Geoecology Chittussiho 10 71000 Ostrava Czech Republic University of Ostrava Faculty of Science Department of Physical Geography and Geoecology Chittussiho 10 71000 Ostrava Czech Republic

Ancient flow type landslides are relatively frequent fossil forms of the relief in mid-mountain conditions of the Czech Carpathian Mountains. Sixty rather distinctive displays of debris flows,rock avalanches,and debris avalanches have been mapped in the uppermost part of the territory. Unlike contemporary sporadic and low volume debris flows,ancient(Pleistocene and Lower Holocene) accumulations are a few orders of magnitude more extensive and were of considerable geomorphologic significance in forming the steep sections of mountain valleys and slopes. This geomorphic pattern does not hold for flow type slides,the source of which is material released as a consequence of numerous deep-seated landslides. Due to deep disruption of slopes,a few high-magnitude flow type landslides(e.g.,rock avalanches),quite rare in flysch mid-mountain conditions,also occurred in the Late Holocene.

关键词： Debris flows Rock avalanches Deep-seated landslides Flysch Western Carpathian Mountains

Strength reduction factors for structural rubbercrete

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Frontiers of Structural and Civil Engineering 2014年第3期8卷 270-281页

作者： Bashar S. MOHAMMED n. j. AZMI Department of Civil Engineering Universiti Teknologi PETRONAS Tronoh Perak 31750 Malaysia Department of Civil Engineering Universiti Tenaga Nasional Putra Jaya 43000 Malaysia

Many researches have been carried out to study the fresh and hardened properties of concrete containing crumb rubber as replacement to fine aggregate by volume, yet there is no specific guideline has been developed on the mix design of the rubbercrete. The experimental program, which has been developed and reported in this paper, is designed and executed to provide such mix design guidelines. A total of 45 concrete mixes with three different water to cement ratio （0.41, 0.57 and 0.68） were cast and tested for fresh and mechanical properties of rubbercrete such as slump, air content, unit weight, compressive strength, flexural strength, splitting tensile strength and modulus of elasticity. Influence of mix design parameters such as percentage of crumb rubber replacement, cement content, water content, fine aggregate content, and coarse aggregate content were investigated. Three levels of slump value （for conventional concrete mixes） has been selected; low, medium and high slump. In each slump level, water content was kept constant. Equations for the reduction factors （RFs） for compressive strength, flexural strength, splitting tensile strength and modulus of elasticity have been developed. These RFs can be used to design rubbercrete mixes based on the conventional mix （0% crumb rubber content）

关键词： crumb rubber recycled tire mix design reduction factor strength modulus elasticity

Coral Reef Recovery Status in South Andaman Islands after the Bleaching Event 2010

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j.urnal of Ocean University of China 2013年第1期12卷 91-96页

作者： n. Marimuthu j. j.rald Wilson n. V. Vinithkumar R. Kirubagaran Department of Marine Biology Faculty of Marine Sciences King Abdulaziz University Andaman and nicobar Centre for Ocean Science and Technology National Institute of Ocean Technology (Ministry of Earth Sciences Govt. of India) Marine Biotechnology National Institute of Ocean Technology (Ministry of Earth Sciences Govt. of India)

The Andaman and nicobar Islands are one of the Union Territories of India, located in the eastern part of the Bay of Bengal. In 2010 summer, the increment in sea surface water temperature （up to 34℃） resulted in the bleaching of about 74% to 77% of corals in the South Andaman. During this event, coral species such as Acropora cerealis, A. humilis, Montipora sp., Favia paIlida, Diploastrea sp., Goniopora sp. Fungia concinna, Gardineroseries sp., Porites sp., Favites abdita and Lobophyllia robusta were severely affected. This study is to assess the recovery status of the reef ecosystem by estimating the percentage of Live Coral cover, Bleached coral cover, Dead coral with algae, Rubble, Sandy fiat, Algal assemblage and other associated organisms, The sedimentation rate （mg cm^-2 d^-1） and coral coverage （%） were assessed during this study period. The average sedimentation rate was ranged between 0.27 and 0.89 mg cm^-2 d^1. The observed post bleaching recovery of coral cover was 21.1% at Port Blair Bay and 13.29% at Havelock Island. The mortality rate of coral cover due to this bleaching was estimated as 2.05% at Port Blair Bay and 9.82% at Havelock Island. Once the sea water temperature resumed back to the normal condition, most of the corals were found recovered.

关键词： coral reef coral recovery coral bleaching sea surface temperature

The organization of societal conflicts by pavement ants Tetramorium caespitum： an agent-based model of amine-mediated decision making

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Current Zoology 2016年第3期62卷 277-284页

作者： Kevin M. HOOVER Andrew n. BUBAK Isaac j. LAW j.zmine D. W. YAEGER Kenneth j. REnnER j.hn G. SWALLOW Michael j. GREEnE Department of Integrative Biology University of Colorado Denver Denver CO 80217-3364 USA neuroscience Program University of Colorado Anschutz Medical Campus Aurora CO 80045 USA Department of Biology University of South Dakota Vermillion South Dakota 57069 USA

Ant colonies self-organize to solve complex problems despite the simplicity of an individual ant＇s brain. Pavement ant Tetramorium caespitum colonies must solve the problem of defending the ter- ritory that they patrol in search of energetically rich forage. When members of 2 colonies randomly interact at the territory boundary a decision to fight occurs when： 1） there is a mismatch in nest- mate recognition cues and 2） each ant has a recent history of high interaction rates with nestmate ants. Instead of fighting, some ants will decide to recruit more workers from the nest to the fighting location, and in this way a positive feedback mediates the development of colony wide wars. In ants, the monoamines serotonin （5-HT） and octopamine （OA） modulate many behaviors associated with colony organization and in particular behaviors associated with nestmate recognition and ag- gression. In this article, we develop and explore an agent-based model that conceptualizes how in- dividual changes in brain concentrations of 5-HT and OA, paired with a simple threshold-based de- cision rule, can lead to the development of colony wide warfare. Model simulations do lead to the development of warfare with 91% of ants fighting at the end of 1 h. When conducting a sensitivity analysis, we determined that uncertainty in monoamine concentration signal decay influences the behavior of the model more than uncertainty in the decision-making rule or density. We conclude that pavement ant behavior is consistent with the detection of interaction rate through a single timed interval rather than integration of multiple interactions.

关键词： agent-based model aggressive behavior ants decision making monoamines octopamine serotonin.