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Scattering of water waves by thin vertical plate submerged below ice-cover surface

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Applied Mathematics and Mechanics(English Edition) 2011年第5期32卷 635-644页

作者： p.MAITI p.RAKSHIT S.BANERJEA Department of Mathematics Jadavpur University Deshapran Birendranath Institution For Boys

The present paper is concerned with scattering of water waves from a vertical plate, modeled as an elastic plate, submerged in deep water covered with a thin uniform sheet of ice. The problem is formulated in terms of a hypersingular integral equation by a suitable application of Green＇s integral theorem in terms of difference of potential functicns across the barrier. This integral equation is solved by a collocation method using a finite series involving Chebyshev polynomials. Reflection and transmission coefficients are obtained numerically and presented graphically for various values of the wave number and ice-cover parameter.

关键词： scattering problem ice-cover surface hypersingular integral equation Green's integral theorem reflection and transmission coefficients

MHD effects on free convective flow over moving semi-infinite vertical cylinder with temperature oscillation

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Applied Mathematics and Mechanics(English Edition) 2011年第11期32卷 1367-1376页

作者： p.LOGANATHAN M.KANNAN p.GANESAN Department of Mathematics Anna University Chennai Chennai 600025India Department of Mathematics Anand Institute of Higher Technology KazhipatturChennai 603103India

Numerical solutions of magnetodynamics （MHD） effects on the free convective flow of an incompressible viscous fluid past a moving semi-infinite vertical cylinder with temperature oscillation are presented. The dimensionless, unsteady, non-linear, and coupled governing partial differential equations are solved by using an implicit finite difference method of the Crank-Nicolson type. The velocity, temperature, and concentration profiles are studied for various parameters. The local skin-friction, the average skinfriction, the Nusselt number, and the Sherwood number are also analyzed and presented graphically. The results are compared with available results in literature, and are found to be in good agreement.

关键词： free convection MHD finite difference method heat and mass transfer

Stellar X-ray Sources in the Rosette Nebula

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Chinese Journal of Astronomy and Astrophysics 2004年第2期4卷 153-165页

作者： W.p.Chen p.S.Chiang J.Z.Li Institute of Astronomy National Central UniversityChung-Li 32054Taiwan National Astronomical Observatories Chinese Academy of SciencesBeijing 100012

We present optical photometric and spectroscopic studies of ROSAT X-ray stellar sources in the Rosette Nebula star-forming region. The brightest X-ray sources are either massive stars or active T Tauri stars associated with the open cluster NGC 2244, or are foreground stars. Some of the spectra of the young stars newly identified in the region are presented.

关键词： stars: early-type stars: pre-main sequence stars: formation HII regions

Solution and Thermodynamic Studies on Binary and Ternary Complexes of Lanthanides

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Journal of Rare Earths 2005年第4期23卷 389-396页

作者： Rajeev Kumar Udai p Singh Department of Chemistry Indian Institute of Technology Roorkee Roorkee-247667 IndiaDepartment of Chemistry Indian Institute of Technology Roorkee Roorkee-247667 India

The interactions of La（ Ⅲ ）, pr（ Ⅲ ）, Nd（ Ⅲ ）, Sm（ Ⅲ ）, Eu（Ⅲ）, Gd（ Ⅲ ）, Dy（ Ⅲ ）, and Yb（ Ⅲ ） with cytosine, 5-bromocytosine, 5-azacytosine and 5-flurocytosine as primary ligands （L） and guanine （A） as secondary ligand for both binary （ 1 ： 1 ） as well as ternary （ 1 ： 1 ： 1 ） systems were investigated by potentiometric equilibrium measurements at 25, 35 and 45 ℃ in aqueous solution （ionic strength, μ = 0.1 mol·dm^-3 NaNO3）. The stability constants of the binary （ 1 ： 1 ） and ternary （ 1 ： 1 ： 1 ） metal-ligand complexes follow the following order La 〈 pr 〈 Nd 〈 Sm 〈 Eu 〉 Gd 〈 Dy 〉 Yb. Results also indicate that the ternary lanthanide complexes of La（Ⅲ）, pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, Gd（Ⅲ）, Dy（Ⅲ）, and Yb（ Ⅲ ） are more stable than corresponding binary lanthanide complexes. The enthalpy （△Hf^o） and entropy （△Sf^o） changes for the formation of binary and ternary complexes were calculated from temperature coefficient data. The △△Sf^o values are positive for all the metal ligand systems. The negative △△Hf^o values indicate the extra stability of the ternary complexes by the exothermic enthalpy changes （△△Sf^o = △TSf^o - △BSf^o and △△Hf^o = △THf^o - △BHf^o where △TSf^o, △THf^o and △BSf^o, △BHf^o are the entropy and enthalpy values associated with the ternary and binary complexes, respectively）. It was also proposed that the guanine is bonded to metal ions through N1/C6 = O and N7 whereas cytosine and its derivatives are bonded through N3 atoms in ternary complexes.

关键词： lanthanide solution studies cytosine thermodynamic properties rare earths

LionRank: lion algorithm-based metasearch engines for re-ranking of webpages

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Science China(Information Sciences) 2018年第12期61卷 65-80页

作者： p.VIJAYA Satish CHANDER Waljat College of Applied Sciences

Due to the rapid growth of the web, the process of collecting the relevant web pages based on the user query is one of the major challenging tasks in recent days. Hence, it is very complicated for the users to know the most relevant information even though various search engines are widely employed. To deal with users' trouble in identifying the relevant information from the web, we have proposed a meta-lion search engine to capture and analyze the ranking scores of various search engines and thereby, generate the re-ranked score results. Accordingly, LionRank, a lion algorithm-based meta-search engine is proposed for the re-ranking of the web pages. Here, different features like text based, factor based, rank based and classifier based features are used by the underlying search engines. In classifier based feature extraction,we have used the fuzzy integrated extended nearest neighbor(FENN) classifier to include the semantics in feature extraction. Moreover, an intelligent re-ranking process is proposed based on the lion algorithm to fuse the features scores optimally. Finally, the results of the proposed LionRank is analyzed with the web page database collected through four benchmark queries, and the quantitative performance are analyzed using precision, recall, and F-score. From the results, we proved that the proposed LionRank obtained the maximum F-score of 81% as compared with that of existing search engines like QuadRank, Outrank, Google,Yahoo, and Bing.

关键词： web technology meta-search engine feature extraction lion algorithm FENN classifier

Negative Selection of Written Language Using Character Multiset Statistics

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Journal of Computer Science & Technology 2010年第6期25卷 1256-1266页

作者： Matti pll Timo Honkela Department of Information and Computer Science School of Science and TechnologyAalto University

We study the combination of symbol frequence analysis and negative selection for anomaly detection of discrete sequences where conventional negative selection algorithms are not practical due to data *** analysis on ergodic Markov chains is used to outline the properties of the presented anomaly detection algorithm and to predict the probability of successful *** are used to evaluate the detection sensitivity and the resolution of the analysis on both generated artificial data and real-world language data including the English *** results on large reference corpora are used to study the effects of the assumptions made in the theoretical model in comparison to real-world data.

关键词： negative selection anomaly detection frequency analysis

A novel supercapacitor-fuel cell hybrid cell

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Rare Metals 2006年第z1期25卷 12-18页

作者： WANG Y ZHENG Jim p Department of Electrical and Computer Engineering Florida A&M University and Florida State University Tallahassee FL 32310 USA Department of Electrical and Computer Engineering Florida A&M University and Florida State University Tallahassee FL 32310 USA

A monolithic hybrid fuel cell (MHFC) with a novel configuration was proposed in an effort to improve the fuel cell performance during instantaneous power changes. A modified direct methanol fuel cell (DMFC) with a layer of hydrous ruthenium dioxide (RuO2·xH2O) sandwiched between the anode catalyst layer and membrane was used to demonstrate the principle of the MHFC. Experimental results indicate that the RuO2·xH2O layer is equivalent to a resistor-capacitor transmission line and functions similar to a capacitor in parallel with the anode electrode. The improvement in dynamic response of the MHFC was experimentally confirmed under step current change and square current pulse operating. The ionic conductivity of the RuO2·xH2O layer was also obtained.

关键词： hybrid devices direct methanol fuel cells hydrous ruthenium dioxide dynamic response

Identifying the general trend of activity of non-stoichiometric metal oxide phases for CO oxidation on pd(111)

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Science China Chemistry 2019年第6期62卷 784-789页

作者： Ziyun Wang p.Hu School of Chemistry and Chemical Engineering Queen's University Belfast

Oxidation state changes under reaction conditions are very common in heterogeneous catalysis. However, due to the limitation of experiment and computational methods, the relation between oxidation state and catalytic activity is not clear. Herein, we obtain the most stable structures of palladium oxide films with different oxidation states on palladium metal surfaces using density functional theory calculations and a state-of-the-art optimization method, namely the particle swarm optimization. These structures clearly show the process of palladium oxide film formation on metallic surfaces. Using CO oxidation as a model reaction, we find that the activities increase first and then decrease with the increase of oxidation states, peaking at pd_4O_3. Our findings offer an understanding of the phase transformation and the activity of non-stoichiometric phases.

关键词： DFT non-stoichiometric oxide CO oxidation

The theory of interaction between wave and basic flow

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Chinese physics B 2008年第3期17卷 1138-1146页

作者：冉令坤 John p.Boyd Laboratory of Cloud-precipitation physics and Severe Storms (LACS) Institute of Atmospheric PhysicsChinese Academy of Sciences Department of Atmospheric Oceanicand Space ScienceUniversity of MichiganAnn ArborMichiganUSA

This paper investigates the interaction between transient wave and non-stationary and non-conservative basic flow. An interaction equation is derived from the zonally symmetric and non-hydrostatic primitive equations in Cartesian coordinates by using the Momentum-Casimir method. In the derivation, it is assumed that the transient disturbances satisfy the linear perturbation equations and the basic states are non-conservative and slowly vary in time and space. The diabatic heating composed of basic-state heating and perturbation heating is also introduced. Since the theory of wave-flow interaction is constructed in non-hydrostatic and ageostrophic dynamical framework, it is applicable to diagnosing the interaction between the meso-scale convective system in front and the background flow. It follows from the local interaction equation that the local tendency of pseudomomentum wave-activity density depends on the combination of the perturbation flux divergence second-order in disturbance amplitude, the local change of basic-state pseudomomentum density, the basic-state flux divergence and the forcing effect of diabatic heating. Furthermore, the tendency of pseudomomentum wave-activity density is opposite to that of basic-state pseudomomentum density. The globally integrated basic-state pseudomomentum equation and wave-activity equation reveal that the global development of basic-state pseudomomentum is only dominated by the basic-state diabatic heating while it is the forcing effect of total diabatic heating from which the global evolution of pseudomomentum wave activity results. Therefore, the interaction between the transient wave and the non-stationary and non-conservative basic flow is realized in virtue of the basic-state diabatic heating.

关键词： wave flow interaction pseudomomentum wave activity diabatic heating Momentum Casimir method