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Existence of Optical Vortex Solitons in Pair Plasmas

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Acta Mathematicae Applicatae Sinica 2023年第3期39卷 571-582页

作者： rui-feng zhang School of Mathematics and Statistics Henan UniversityKaifeng 475004China

Optical vortices arise as phase dislocations of light fields and they are of importance in modern optical *** this study,we employ the calculus of variations method to develop an existence theory for the steady state vortex solutions of a nonlinear Schr?dinger type equation to model light waves that propagate in a medium with a new focusing-defocusing ***,we demonstrate the existence of positive radially symmetric solutions by constrained minimization,where we give some interesting explicit estimates related to vortex winding numbers and the wave propagation ***,we establish the existence of saddle-point solutions through a mountain-pass argument.

关键词： Calculus of variations mountain-pass theorem pair plasmas nonlinear Schr?dinger type equation optical vortices

The Global Attractors for the Dissipative Generalized Hasegawa-Mima Equation

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Acta Mathematicae Applicatae Sinica 2008年第1期24卷 19-28页

作者： rui-feng zhang Institute of Applied Mathematics Henan University College of Mathematics and Information Science Henan University Kaifeng 475001 China

The long time behavior of solutions of the generalized Hasegawa-Mima equation with dissipation term is considered. The existence of global attractors of the periodic initial value problem is proved, and the estimate of the upper bound of the Hausdorff and fractal dimensions for the global attractors is obtained by means of uniform a priori estimates method.

关键词： Hasegawa-Mima equation global attractors hausdorff dimension fractal dimension

AN EXPLICIT PSEUDO-SPECTRAL SCHEME WHIT ALMOST UNCONDITIONAL STABILITY FOR THE CAHN-HILLIARD EQUATION

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Journal of Computational Mathematics 2000年第2期18卷 165-172页

作者： Bai-nian Lu rui-feng zhang Department of Mathematics Shaanxi Normal UniversityXi’an 710062China Department of Mathematics Kaifeng Normal CollageKaifengChina

Proposes an explicit fully discrete three-level pseudo-spectral scheme with unconditional stability for the Cahn-Hilliard equation. Equations for pseudo-spectral scheme; Analysis of linear stability of critical points.

关键词： Cahn-Hilliard equation pseudo-spectral scheme almost unconditional stability linear stability for criticlal points numerical experiments

The Solutions of the Coupled Einstein-Maxwell Equations and Dilaton Equations

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Acta Mathematicae Applicatae Sinica 2018年第3期34卷 485-492页

作者： rui-feng zhang Ya GU Institute of Contemporary Mathematics Henan University Kaifeng 475004 China School of Mathematics and Statistics Henan University Kaifeng 475004 China

In this paper, we consider extremely charged static perfect fluid distributions with a dilaton field in the framework of general relativity. By using calculus of variations, we establish the existence theorem for the solutions of this important gravitational system. We show that there is a continuous family of smooth solutions realizing asymptotically flat space metrics.

关键词： nonlinear elliptic equations the variational method the asymptotic estimates.

The Existence of Solutions for the Problem in the Optical Lattice with Nonlocal Nonlinearity

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Acta Mathematicae Applicatae Sinica 2012年第4期28卷 681-690页

作者： rui-feng zhang Ren-tao LIU Institute of Contemporary Mathematics Henan University College of Mathematics and Information Science Henan University

We address the impact of nonlocality in the physical features exhibited by solitons supported by Kerr-type nonlinear media with an imprinted optical lattice. We discuss the solitons solution for a class of nonlinear SchrSdinger equations in the optical lattice with nonlocal nonlinearity. We also show via a uniform priori estimate that existence and uniqueness of the global solution for the initial problem.

关键词： SchrSdinger equation Cauchy problem contract mapping principle Calerkin method

Topological Multiple Recurrence of Weakly Mixing Minimal Systems for Generalized Polynomials

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Acta Mathematica Sinica,English Series 2021年第12期37卷 1847-1874页

作者： rui feng zhang Jian Jie ZHAO School of Mathematics Hefei University of TechnologyHefei 230009P.R.China CAS Wu Wen-Tsun Key Laboratory of Mathematics and School of Mathematics University of Science and Technology of ChinaHefei 230026P.R.China

Let(X,T)be a weakly mixing minimal system,p_(1),...,p_(d) be integer-valued generalized polynomials and(p_(1),p_(2),...,p_(d))be *** there exists a residual subset X_(0) of X such that for all x∈X0,{(T^(p1(n))x,...,T... 详细信息

关键词： Generalized polynomials weakly mixing multiple recurrence

Expression of vascular endothelial growth factors A and C in human pancreatic cancer

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World Journal of Gastroenterology 2006年第2期12卷 280-286页

作者： rui-feng Tang Shu-Xia Wang Li Peng Shun-Xiang Wang Meng zhang Zhi-feng Li Zhi-Ming zhang Yan Xiao feng-rui zhang Department of Hepatobiliary Surgery 4th Hospital Hebei Medical University Shijiazhuang 050011 Hebei Province China Department of Dermatology 4th Hospital Hebei Medical University Shijiazhuang 050011 Hebei Province China

AIM： To study the expression of vascular endothelial growth factor A （VEGF-A） and VEGF-C and to determine whether the presence of VEGF-A and VEGF-C was associated with the clinicopathologic characteristics of pancreatic cancer. METHODS： VEGF-A and VEGF-C mRNA transcripts were examined by Northern blot in 6 human pancreatic cancer cell lines and 8 normal pancreatic tissues and 8 pancreatic carcinoma specimens. The expression of VEGF-A and VEGF-C proteins was examined by Western blot in the tested cell lines and by immunohistochemical stain in 50 pancreatic carcinoma samples. RESULTS： VEGF-A and VEGF-C mRNA transcripts were present in all the 6 human pancreatic cancer cell lines. Immunoblotting revealed the presence of VEGF-A and VEGF-C proteins in all the cell lines. Northern blot analysis of total RNA revealed 3.0-fold and 3.6-fold increase in VEGF-A and VEGF-C mRNA transcript in the cancer samples, respectively. Immunohistochemical analysis confirmed the expression of VEGF-A and VEGF-C in cancer cells within the tumor mass. Immunohistochemical analysis of 50 pancreatic cancer tissue samples revealed the presence of VEGF-A and VEGF-C immunoreactivity in 50% and 80% of the cancer tissue samples, respectively. The presence of VEGF-A in these cells was associated with larger tumor size and enhanced local spread （x^2= 6.690, P= 0.035〈0.05） but was not associated with decreased patient survival. However, the presence of VEGF-C in the cancer cells was associated with increased lymph node metastasis （x^2= 5.710, P= 0.017〈0.05）,but was not associated with decreased patient survival. There was no correlation between the expression of VEGF-A and VEGF-C in the same cancer cells. CONCLUSION： VEGF-A and VEGF-C are commonly overexpressed in human pancreatic cancer and may contribute to tumor growth and lymph node metastasis, There is no relationship between the expression of VEGF-A and VEGF-C in pancreatic cancer.

关键词： Pancreatic cancer Vascular endothelial growth factor-A Vascular endothelial growth factor-C Survival

Cu/Li Ratio on the Microstructure Evolution and Corrosion Behaviors of Al–xCu–yLi–Mg Alloys

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Acta Metallurgica Sinica(English Letters) 2020年第9期33卷 1201-1216页

作者： Dan-Yang Liu Jin-feng Li Yong-Cheng Lin Peng-Cheng Ma Yong-Lai Chen Xu-Hu zhang rui-feng zhang School of Materials Science and Engineering Central South UniversityChangsha 410083China School of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China Key Laboratory of Nonferrous Materials Science and Engineering of Ministry of Education Central South UniversityChangsha 410083China Aerospace Research Institute of Materials and Processing Technology Beijing 100076China

The microstructure evolution and the corrosion feature of Al–x Cu– y Li–Mg alloys( x : y = 0.44, 1.65 and 4.2) were systematically investigated under the same artificial aging conditions. The relationships between types of precipitates and mechanical performance, as well as electrochemical behaviors, were discussed. Our results show that different types of precipitates can be obtained in alloys with different Cu/Li mass ratios, which significantly influences the mechanical performance of the alloys and substantial corrosion behaviors. Specifically, the analogous corrosion evolution in the aging Al– x Cu– y Li–Mg alloys was first ascertained to be derived from the growth mechanism of the precipitates at the grain boundary(GB). Moreover, a small number of GB precipitates can be obtained in the aged alloy with the lowest Cu/Li mass ratio, thereby resulting in the largest intergranular corrosion resistance. A higher proportion of the GB T1 phase in the continuous precipitates induces higher corrosion sensitivity in alloy with a high Cu/Li mass ratio.

关键词： Al–Cu–Li–Mg alloy Cu/Li mass ratio Microstructure evolution Corrosion behaviors

Starlet:Network defense resource allocation with multi-armed bandits for cloud-edge crowd sensing in IoT

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Digital Communications and Networks 2024年第3期10卷 586-596页

作者： Hui Xia Ning Huang Xuecai feng rui zhang Chao Liu College of Computer Science and Technology Ocean University of ChinaQingdao266100China

The cloud platform has limited defense resources to fully protect the edge servers used to process crowd sensing data in Internet of *** guarantee the network's overall security,we present a network defense resource allocation with multi-armed bandits to maximize the network's overall ***,we propose the method for dynamic setting of node defense resource thresholds to obtain the defender(attacker)benefit function of edge servers(nodes)and ***,we design a defense resource sharing mechanism for neighboring nodes to obtain the defense capability of ***,we use the decomposability and Lipschitz conti-nuity of the defender's total expected utility to reduce the difference between the utility's discrete and continuous arms and analyze the difference ***,experimental results show that the method maximizes the defender's total expected utility and reduces the difference between the discrete and continuous arms of the utility.

关键词： Internet of things Defense resource sharing Multi-armed bandits Defense resource allocation