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Degree Conditions on Copies of Forests in Graphs

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Journal of the Operations research Society of China 2023年第3期11卷 667-672页

作者： Xiao-Dong Chen Shuai-Jun Chen Ming-Chu Li School of Mathematics Liaoning Normal UniversityDalian116029LiaoningChina College of Science Liaoning University of TechnologyJinzhou121001LiaoningChina School of Softsware Dalian University of TechnologyDalian116024LiaoningChina

For a graph G,letμ(G)=min{max{d(x),d(y)}:x≠y,xy∉E(G),x,y∈V(G)}if G is non-complete,otherwise,μ(G)=+∞.For a given positive number s,we call that a graph G satisfies Fan-type conditions ifμ(G)≥***μ(G)≥s,then a vertex v is called a small vertex if the degree of v in G is less than *** this paper,we prove that for a forest F with m edges,if G is a graph of order n≥|F|andμ(G)≥m with at most max{n−2m,0}small vertices,then G contains a copy of *** also give examples to illustrate both the bounds in our result are best possible.

关键词： Fan-type conditions Forest Copy Small vertex

Adaptive Numerical Approach for Optimal Control of a Single Train

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Journal of Systems Science & Complexity 2019年第4期32卷 1053-1071页

作者： WU Xiang ZHANG Kanjian CHENG Ming School of Mathematical Sciences Guizhou Normal UniversityGuiyang 550001China School of Electrical Engineering Southeast UniversityNanjing 210096China School of Automation Southeast UniversityNanjing 210096China Key Laboratory of Measurement and Control of CSE Ministry of EducationSoutheast UniversityNanjing 210096China

This paper considers the optimal control problem of a single train,which is formulated as an optimal control problem of nonlinear systems with switching *** switching sequence and the switching time are decision variables to be chosen *** speaking,it is very difficult to solve this problem analytically due to its nonlinear nature,the complexity of the controller,and the existence of system state and control input *** obtain the numerical solution,by introducing binary functions for every value of the control input,relaxing the binary functions,and imposing a penalty function on the relaxation,the problem is transformed into a parameter optimization problem,which can be efficiently solved by using any gradient-based numerical ***,the authors propose an adaptive numerical approach to solve this *** results indicate that any optimal solution of the parameter optimization problem is also an optimal solution of the original ***,an optimal control problem of a single train illustrates that the adaptive numerical approach proposed by us is less time-consuming and obtains a better cost function value than the existing approaches.

关键词： Adaptive numerical approach nonlinear system optimal control switching controller train control

Determination of L-phenylalanine by cucurbit[7]uril sensitized fluorescence quenching method

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Chinese Chemical Letters 2011年第7期22卷 851-854页

作者： Chang Feng Li Li Ming Du Hao Wu Ying Xia Chang Analytical and Testing Center Shanxi Normal University Linfen 041004 China School of Chemistry and Materials Science Shanxi Normal University Linfen 041004 China

The determination method of L-phenylalartine （LPA） by fluorescence quenching was developed. The assay was based on the combination of the cucurbit[7]uril （CB [7]） with palmatine hydrochloride （PAL） reaction. In the presence of CB [7], the fluorescence of PAL was quenched by LPA which can be employed to detect LPA. Under the optimal conditions, a linear range 3.63 ×10^-8- 9.68 ×10^-6 mol/L and a detection limit 1.27 ×10^-8 mol/L of LPA were obtained. The relative standard deviation （R.S.D） was 1.8% obtained from a series of 11 standards each containing 6.05 ×10^-6 mol/L of LPA. This paper also discusses the mechanism of fluorescence indicator probe.

关键词： L-phenylalanine Palmatine hydrochloride Cucurbituril Fluorescent probe

MULTIPLICITY OF POSITIVE SOLUTIONS FOR A CLASS OF CONCAVE-CONVEX ELLIPTIC EQUATIONS WITH CRITICAL GROWTH

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Acta Mathematica Scientia 2018年第2期38卷 497-518页

作者：廖家锋蒲洋唐春雷 School of Mathematics and Statistics Southwest University Chongqing 400715 China School of Mathematics and Information China West Normal University Nanchong 637002 China

In this article, the following concave and convex nonlinearities elliptic equations involving critical growth is considered,{-△u=g（x）｜u｜2＊-2u＋λf（x）｜u｜q-2u,x∈Ω u=0,x∈δΩ where Ω RN（N ≥ 3） is an open bounded domain with smooth boundary, 1 〈 q 〈 2, λ 〉 0. 2＊= 2N/N-2 is the critical Sobolev exponent, f ∈L2＊/2N/N-2 is nonzero and nonnegative, and g E （Ω） is a positive function with k local maximum points. By the Nehari method and variational method, k ＋ 1 positive solutions are obtained. Our results complement and optimize the previous work by Lin [MR2870946, Nonlinear Anal. 75（2012） 2660-26711.

关键词： Semilinear elliptic equations critical growth positive solutions Nehari method variational method

Explaining the Multiwavelength Emission of Hard-Te V BL Lac Objects Using a Truncated Conical Jet Model

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research in Astronomy and Astrophysics 2022年第4期22卷 42-54页

作者： Maichang Lei Yuan Zheng Jianfu Zhang Jiancheng Wang College of Physics and Engineering Technology Xingyi Normal University for NationalitiesXingyi 562400China Department of Physics Xiangtan UniversityXiangtan 411105China Yunnan Observatories Chinese Academy of SciencesKunming 650216China

Hard-Te V BL Lac objects are newly identified populations of active galactic nuclei with the emittedγ-ray photons well above Te V *** this paper,we explain the multiwavelength emission of six Hard-Te V BL Lac objects by using a truncated conical emission region of the jet,where the electron distribution is obtained by numerically solving the evolution equation along the jet *** comparison,we also apply the model to Mrk 421and Mrk 501,which are the potential candidates for the hard Te V *** demonstrate that the model can satisfactorily reproduce the spectral energy distributions of eight sources,particularly of six Hard-Te V sources,where no extreme minimum Lorentz factor of the electron population is *** contrast with Mrk 421 and Mrk 501,six Hard-Te V sources have rather low magnetization in emitting regions and high cutoff energies of the electron distributions.

关键词： galaxies:active (galaxies:)BL Lacertae objects:general radiation mechanisms:non-thermal

Robust asymptotic stability for BAM neural networks with time-varying delays via LMI approach

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Applied Mathematics(A Journal of Chinese Universities) 2009年第3期24卷 282-290页

作者： LIU Jia ZONG Guang-deng ZHANG Yun-xi research Institute of Automation Qufu Normal University Qufu 273165 China School of Automation Nanjing University of Science & Technology Nanjing 210064 China

Several novel stability conditions for BAM neural networks with time-varying delays are *** on Lyapunov-Krasovskii functional combined with linear matrix inequality approach,the delay-dependent linear matrix inequality（LMI） conditions are established to guarantee robust asymptotic stability for given delayed BAM neural *** criteria can be easily verified by utilizing the recently developed algorithms for solving LMIs.A numerical example is provided to demonstrate the effectiveness and less conservatism of the main results.

关键词： robust asymptotic stability bidirectional associative memory (BAM) neural networks timevarying delays linear matrix inequality(LMI) Lyapunov-Krasovskii functional

Coherent Control of Molecular Orientation by a Terahertz Few-Cycle Laser Pulse

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Chinese Physics Letters 2013年第2期30卷 82-85页

作者： QIN Chao-Chao LIU Yu-Zhu ZHANG Xian-Zhou LIU Yu-Fang Department of Physics Henan Normal UniversityXinxiang 453007 College of Physics and Opto-electronics Engineering Nanjing University of Information Science&TechnologyNanjing 210044

The coherent control of molecular orientation by a terahertz few-cycle laser pulse is theoretically *** is demonstrated that the field-free molecular orientation results from the interference contributions between the odd and even rotational wave packet,and therefore the constructive and destructive interferences lead to the observation of the positive and negative orientations,corresponding to the positive and negative ***,the enhancement or suppression of the molecular orientation can be coherently manipulated by precisely controlling the carrier-envelope phase of the terahertz few-cycle pulse.

关键词： coherent Pulse Molecular

Constructions of 1（1/2）-Designs from Unitary Geometry over Finite Fields

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Algebra Colloquium 2017年第3期24卷 381-392页

作者： Rongquan Feng Yang Zhang LMAM School of Mathematical Sciences Peking University Beijing 100871 China Department of Mathematics and Statistics Texas Tech University Lubbock TX 79409 USA

In this paper, we construct some 1（1/2）-designs, which are also known as partial geometric designs, using totally isotropic subspaces of the unitary space. Phrthermore, these 1（1/2）-designs yield six infinite fami... 详细信息

关键词： 1(1/2)-design unitary space totally isotropic subspace directed strongly regulargraph

Synthesis,Fluorescence and Magnetic Properties of a New Europium(Ⅲ) Complex Eu(L)3(Phen)2

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Chinese Journal of Structural Chemistry 2017年第1期36卷 170-174页

作者：谭雄文李昶红李衡峰杨颖群 School of Materials Science and Engineering Central South University Key Laboratory of Functional Organometallic Materials of Hunan Province College Department of Chemistry and Materials ScienceHengyang Normal University Department of Chemical Engineering Hunan Institute of Technology

A new europium（III） complex Eu（L）3（Phen）2（1） with 2-benzoylbenzoic acid（HL） and 1,10-phenanthroline（Phen） as ligands has been synthesized. Crystal data for the complex are as follows： monoclinic, space group P21/c, a = 2.2577（4）, b = 1.23484（19）, c = 1.8789（3） nm, β = 94.918（3）o, V = 5.2189（14） nm^3, Dc = 1.512 g/cm^3, Z = 4, μ（Mo Kα） = 1.269 mm^-1, F（000） = 2408, the final R = 0.0433 and w R = 0.1038. The Eu（III） ion is coordinated by nine atoms to give a single-capped square antiprism coordination geometry. 1 shows two intense fluorescence emission bands arising from the transitions of Eu^3＋： ^5D0→^7F1（597 nm） and ^5D0→^7F2（615 nm） with an excitation wavelength of 396 nm. In addition, 1 displays antiferromagnetic property at low temperature.

关键词： europium(Ⅲ) complex 2-benzoylbenzoic acid crystal structure fluorescent and magnetic properties