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CHROMATIC NUMBER OF SQUARE OF MAXIMAL OUTERPLANAR GRAPHS

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Applied Mathematics(A Journal of Chinese Universities) 2007年第2期22卷 163-168页

作者： Luo Xiaofang Yiwu industrial and commercial college Yiwu 322000 China

Let x（G^2） denote the chromatic number of the square of a maximal outerplanar graph G and Q denote a maximal outerplanar graph obtained by adding three chords y1 y3, y3y5, y5y1 to a 6-cycle y1y2…y6y1. In this paper, it is proved that △ ＋ 1 ≤ x（G^2） ≤△ ＋ 2, and x（G^2） = A ＋ 2 if and only if G is Q, where A represents the maximum degree of G.

关键词： chromatic number maximal outerplanar graph square of graph maximum degree

Effect of charge compensation on emission spectrum of Ca_2SiO_4:Dy^(3+) phosphor

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Chinese Optics Letters 2008年第4期6卷 274-275页

作者：李盼来张子才张坤杨志平王志军郭庆林 college of Physics Science and Technology Hebei University Baoding 071002 industrial and commercial college Hebei University Baoding 071002

The Ca2SiO4：Dy^3＋ phosphor was synthesized by the high temperature solid-state reaction method in air. The emission spectrum of Ca2SiO4：Dy^3＋ phosphor shows several bands at 486, 575, and 665 nm under the 365-nm excitation. The effects of Li^＋, Na^＋, and K^＋ on the emission spectrum of Ca2SiO4：Dy^3＋ phosphor were studied. The results show that the emission spectrum intensity is greatly influenced by Li^＋, Na^＋, and K^＋. The charge compensation concentration corresponding to the maximum emission intensity is different with different charge compensations.

关键词： Calcium compounds Dysprosium Emission spectroscopy Rare earth additions Solid state reactions

A novel weighted evolving network model based on clique overlapping growth

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Journal of Central South University 2010年第4期17卷 830-835页

作者：杨旭华王波孙豹 college of Information Engineering Zhejiang University of Technology Department of Computer Science and Engineering Yiwu Industrial and Commercial College

A novel weighted evolving network model based on the clique overlapping growth was *** model shows different network characteristics under two different selection mechanisms that are preferential selection and random *** the basis of mean-field theory,this model under the two different selection mechanisms was *** analytic equations of distributions of the number of cliques that a vertex joins and the vertex strength of the model were *** is proved that both distributions follow the scale-free power-law distribution in preferential selection mechanism and the exponential distribution in random selection mechanism,*** analytic expressions of exponents of corresponding distributions were *** agreement between the simulations and analytical results indicates the validity of the theoretical ***,three real transport bus networks(BTNs) of Beijing,Shanghai and Hangzhou in China were *** analyzing their network properties,it is discovered that these real BTNs belong to a kind of weighted evolving network model with clique overlapping growth and random selection mechanism that was proposed in this context.

关键词： weighted network clique overlapping mean-field theory bus transport network

Grammian Solutions to a Variable-Coefficient KP Equation

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Chinese Physics Letters 2008年第2期25卷 357-358页

作者：叶灵娅吕逸能张翼金慧萍 Department or Mathematics Zhejiang Normal University Jinhua 321004 Yiwu industrial and commercial college Yiwu 322000

Solutions in the Grammian form for a variable-coefficient Kadomtsev-Petviashvili （KP） equation which has the Wronskian solutions are derived by means of Pfaffian derivative formulae.

关键词： pulsars x-ray spectra relativity and gravitation redshift

Improvement Up-conversion Luminescence Properties of SrIn_2O_04:Er^(3+) by Doping Yb^(3+) as Sensitizer

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Journal of the Chinese Ceramic Society 2016年第2期 78-83页

作者： QI Shuai TIAN Yinghe LI Yong ZHANG Huan LI Xiang YOU Jianqi YUAN Xiaoxian WANG Zhijun LI Panlai LIU Haiyan college of Physics Science & Technology Hebei University industrial & commercial college Hebei University

A series of Yb^(3+)/Er^(3+) or Er^(3+) doped SrIn_2O_4 were synthesized by a high temperature solid state *** up-conversion luminescence property and the phase formation of SrIn_2O_4:Er^(3+) and SrIn_2O_4:Yb^(3+),Er^(3+) were investigated by X-ray diffraction(XRD) and spectral *** XRD pattern shows that incorporating different amounts of Yb^(3+)and Er^(3+) have no influence on the phase formation of SrIn_2O_*** up-conversion luminescence spectrum of SrIn_2O_4:Er^(3+) presented a weak luminescence due to ground state absorption of Er^(3+).However,Yb^(3+)/Er^(3+) codoped SrIn_2O_4 depicted the green(525 and 551 run) and red(662 nm) up-conversion luminescence which were assigned to the energy transfer from the Yb^(3+) transition ~2F_(7/2)-~2F_(5/2) to the Er^(3+) transitions ~2H_(11/2)-~4I_(15/2) and ~4F_(9/2-~4I_(15/2),*** possible up-conversion luminescence mechanism of SrIn_2O_4:Yb^(3+),Er^(3+) was *** results could be helpful to the development of up-conversion luminescence materials.

关键词： up-conversion luminescence SrIn2O4 Er Yb co-doped

Mean-field Theory for Some Bus Transport Networks with Random Overlapping Clique Structure

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Communications in Theoretical Physics 2010年第4期53卷 688-692页

作者：杨旭华孙豹王波孙优贤 college of Information Engineering Zhejiang University of Technology State Key Laboratory of industrial Control Technology Zhejiang University Department of Computer Science and Engineering Yiwu Industrial and Commercial College

Transport networks, such as railway networks and airport networks, are a kind of random network with complex topology. Recently, more and more scholars paid attention to various kinds of transport networks and try to explore their inherent characteristics. Here we study the exponential properties of a recently introduced Bus Transport Networks （BTNs） evolution model with random overlapping clique structure, which gives a possible explanation for the observed exponential distribution of the connectivities of some BTNs of three major cities in China. Applying mean-field theory, we analyze the BTNs model and prove that this model has the character of exponential distribution of the connectivities, and develop a method to predict the growth dynamics of the individual vertices, and use this to calculate analytically the connectivity distribution and the exponents. By comparing mean-field based theoretic results with the statistical data of real BTNs, we observe that, as a whole, both of their data show similar character of exponential distribution of the connectivities, and their exponents have same order of magnitude, which show the availability of the analytical result of this paper.

关键词： mean-field theory bus transport network evolution model exponential distribution

Ru/NiMnB spherical cluster pillar for highly proficient green hydrogen electrocatalyst at high current density

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Journal of Energy Chemistry 2025年第1期100卷 397-408页

作者： Md Ahasan Habib Shusen Lin Mehedi Hasan Joni Sumiya Akter Dristy Rutuja Mandavkar Jae-Hun Jeong Jihoon Lee Department of Electronic Engineering College of Electronics and Information Kwangwoon University

Advanced OER/HER electrocatalytic alternatives are crucial for the wide adaptation of green hydrogen ***,Ru/NiMnB spherical cluster pillar （SCP）,denoted as Ru/NiMnB,is synthesized using a combination of electro-deposition and hydrothermal *** investigation of Ru doping in the NiMnB matrix revealed significant improvements in electrocatalytic *** Ru/NiMnB SCPs demonstrate superior OER/HER activity with low overpotentials of 150 and 103 mV at 50mA/cm2in 1 M KOH,making them highly competitive with state-of-the-art ***,the Ru/NiMnB SCPs exhibit a low 2-E cell voltage of 2.80 V at ultra-high current density of 2,000 m A/cm2in 1 M KOH,outperforming the standard benchmark electrodes of RuO2||Pt/C,thereby positioning Ru/NiMnB as one of the best bifunctional *** SCPs exhibit exceptional high-current characteristics,stability and corrosion resistance,as evidenced by continuous operation at 1,000 mA/cm2high-current density for over 150 h in 6 M KOH at elevated temperatures under harsh industrial *** a small amount of Ru incorporation significantly enhances the electrocatalytic performances of NiMnB,attributed to increased active sites and improved intrinsic properties such as conductivity,adsorption/desorption capability and reaction ***,Ru/NiMnB SCPs present a promising bi-functional electrode concept for efficient green H2production.

关键词： Advanced electrocatalyst High current Corrosion resistance industrial requirement

Some Results on Distance Two Labelling of Outerplanar Graphs

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Acta Mathematicae Applicatae Sinica 2009年第1期25卷 21-32页

作者： Wei- fan Wang Xiao-fang Lu Department of Mathematics Zhejiang Normal University Jinhua 321004 China Yiwu industrial and commercial college Zhejiang Yiwu 322000 China

Let G be an outerplanar graph with maximum degree △. Let χ（G^2） and A（G） denote the chromatic number of the square and the L（2, 1）-labelling number of G, respectively. In this paper we prove the following results：（1） χ（G^2） = 7 if △= 6; （2） λ（G） ≤ △ ＋5 if △ ≥ 4, and ）,（G）≤ 7 if △ = 3; and （3） there is an outerplanar graph G with △ = 4 such that ）λ（G） = 7. These improve some known results on the distance two labelling of outerplanar graphs.

关键词： L(2, 1)-labelling chromatic number outerplanar graph

Some Exact Solutions of Variable Coefficient Cubic-Quintic Nonlinear Schrdinger Equation with an External Potential

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Communications in Theoretical Physics 2009年第3期51卷 391-394页

作者： ZHU Jia-Min LIU Yu-Lu Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China Yiwu industrial and commercial college Yiwu 322000 China

By constructing appropriate transformations and an extended elliptic sub-equation approach, we find some exact solutions of variable coefficient cubic-quintie nonlinear Schrodinger equation with an external potential, which include bell and kink profile solitary wave solutions, singular solutions, triangular periodic wave solutions and so on.

关键词： cubic-quintic nonlinear Schrodinger equation variable coefficient exact solution