Tangshan, China

Xuzhou Normal University

Tangshan, China

Jiangsu Normal University is a national university located in Xuzhou, Jiangsu province, China. Wikipedia.

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Pang H.-K.,Xuzhou Normal University | Sun H.-W.,University of Macau
Journal of Computational Physics | Year: 2012

The fractional diffusion equation is discretized by the implicit finite difference scheme with the shifted Grünwald formula. The scheme is unconditionally stable and the coefficient matrix possesses the Toeplitz-like structure. A multigrid method is proposed to solve the resulting system. Meanwhile, the fast Toeplitz matrix-vector multiplication is utilized to lower the computational cost with only O(NlogN) complexity, where N is the number of the grid points. Numerical experiments are given to demonstrate the efficiency of the method. © 2011 Elsevier Inc.

Xie X.-J.,Qufu Normal University | Duan N.,Xuzhou Normal University | Yu X.,Nanjing Southeast University
IEEE Transactions on Automatic Control | Year: 2011

This technical note considers a class of high-order stochastic nonlinear systems with stochastic integral input-to-state stability (SiISS) inverse dynamics, and drift and diffusion terms depending upon the stochastic inverse dynamics and all the states. A new design and analysis approach to the problem of state-feedback global regulation is developed to guarantee that all the signals of the closed-loop system are bounded almost surely and the states can be regulated to zero almost surely. © 2010 IEEE.

Xie X.-J.,Qufu Normal University | Duan N.,Xuzhou Normal University
IEEE Transactions on Automatic Control | Year: 2010

This note considers output tracking of high-order stochastic nonlinear systems without imposing any restriction on the high-order and the drift and diffusion terms. By using the backstepping design technique, a smooth state-feedback controller is given to guarantee that the solution process is bounded in probability and the error signal between the output and the reference signal can be regulated into a small neighborhood of the origin in probability. A practical example of stochastic benchmark mechanical system and simulation are provided to demonstrate the effectiveness of the control scheme. © 2010 IEEE.

Duan N.,Xuzhou Normal University | Xie X.-J.,Xuzhou Normal University | Xie X.-J.,Qufu Normal University
IEEE Transactions on Automatic Control | Year: 2011

For a class of stochastic nonlinear systems in which the drift and diffusion vector fields depend on the unmeasurable states besides the measurable output, the research purpose of this technical note is to find the maximum value interval of observer gain for the desired control performance. For this interval, the designed output-feedback controller ensures that the equilibrium at the origin is globally asymptotically stable in probability, and the inverse optimal stabilization in probability is achieved. © 2011 IEEE.

Wang F.,Xuzhou Normal University
Advanced Materials Research | Year: 2012

In order to obtain accurate results from computer simulation of the dynamic behavior of conveyor belts an accuracy description of the resistance forces, especially the indentation rolling resistance, is necessary. Since the indentation rolling resistance can account for the major part of the total rolling resistance, it is important to calculate it using a proper method. A new full two-dimensional semi-analytical method based on Maxwell model is developed to rigorously and efficiently simulate and solve the indentation rolling resistance of conveyor belts. In this method, the solution is expanded into a set of Fourier series, a so-called Maxwell model characterizing the viscoelastic properties for the belt cover material is used to relate Fourier coefficients, and a special boundary element is developed to handle the rolling contact boundary condition. A verification example is given to validate the methodology. © (2012) Trans Tech Publications.

Lv Y.,Xuzhou Normal University | Du Z.,Xuzhou Normal University
Nonlinear Analysis: Real World Applications | Year: 2011

In this paper, a Volterra model with mutual interference and Holling III type functional response is investigated, some sufficient conditions which guarantee the existence and global attractivity of a positive periodic solution for the system are obtained and two examples are given to verify the results by using MatLab. Furthermore, our results improve the main results in the literature. © 2011 Elsevier Ltd. All rights reserved.

Xiao Z.-J.,Nanjing Normal University | Liu X.,Xuzhou Normal University
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2011

In this work, we calculate the CP-averaged branching ratios and the polarization fractions of the charmless hadronic Bc→A 2A3 decays within the framework of perturbative QCD (pQCD) approach, where A is either a light P13 or P11 axial-vector meson. These 32 decay modes can occur through the annihilation topology only. Based on the perturbative calculations and phenomenological analysis, we find the following results: (a) the branching ratios of the considered 32 Bc→A 2A3 decays are in the range of 10-5 to 10 -8; (b) Bc→a1b1, K̄10K1+ and some other decays have sizable branching ratios and can be measured at the LHC experiments; (c)the branching ratios of Bc→A 2(P11)A3(P11) decays are generally much larger than those of Bc→A2(P13)A3(P13) decays with a factor around (10∼100); (d)the branching ratios of Bc→K̄10K1+ decays are sensitive to the value of θK, which will be tested by the running LHC and forthcoming SuperB experiments; (e)the large longitudinal polarization contributions govern most considered decays and play the dominant role. © 2011 American Physical Society.

Shi F.,Xuzhou Normal University | Tao Z.-L.,Hefei University of Technology | Luo S.-W.,Hefei University of Technology | Tu S.-J.,Xuzhou Normal University | Gong L.-Z.,Hefei University of Technology
Chemistry - A European Journal | Year: 2012

Catalytic asymmetric construction of the biologically important spiro[pyrrolidin-3,2'-oxindole] scaffold with contiguous quaternary stereogenic centers in excellent stereoselectivities (up to >99:1 d.r., 98 % ee) has been established by using an organocatalytic 1,3-dipolar cycloaddition of isatin-based azomethine ylides. This protocol represents the first example of catalytic asymmetric 1,3-dipolar cycloadditions involving azomethine ylides generated in situ from unsymmetrical cyclic ketones. In addition, theoretical calculations were performed on the transition state of the reaction to understand the stereochemistry. Preliminary bioassays with these spiro[pyrrolidin-3,2'-oxindole] revealed that several compounds showed moderate cytotoxicity to SW116 cells. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Yu J.,Hefei University of Technology | Shi F.,Xuzhou Normal University | Gong L.-Z.,Hefei University of Technology
Accounts of Chemical Research | Year: 2011

Optically pure nitrogenous compounds, and especially nitrogen-containing heterocycles, have drawn intense research attention because of their frequent isolation as natural products. These compounds have wide-ranging biological and pharmaceutical activities, offering potential as new drug candidates. Among the various synthetic approaches to nitrogenous heterocycles, the use of asymmetric multicomponent reactions (MCRs) catalyzed by chiral phosphoric acids has recently emerged as a particularly robust tool. This method combines the prominent merits of MCRs with organocatalysis, thus affording enantio-enriched nitrogenous heterocyclic compounds with excellent enantioselectivity, atom economy, bond-forming efficiency, structural diversity, and complexity. In this Account, we discuss a variety of asymmetric MCRs catalyzed by chiral phosphoric acids that lead to the production of structurally diverse nitrogenous heterocycles.In MCRs, three or more reagents are combined simultaneously to produce a single product containing structural contributions from all the components. These one-pot processes are especially useful in the construction of heterocyclic cores: they can provide a high degree of both complexity and diversity for a targeted set of scaffolds while minimizing the number of synthetic operations. Unfortunately, enantioselective MCRs have thus far been relatively underdeveloped. Particularly lacking are reactions that proceed through imine intermediates, which are formed from the condensation of carbonyls and amines. The concomitant generation of water in the condensation reaction can deactivate some Lewis acid catalysts, resulting in premature termination of the reaction. Thus, chiral catalysts typically must be compatible with water for MCRs to generate nitrogenous compounds. Recently, organocatalytic MCRs have proven valuable in this respect. Brønsted acids, an important class of organocatalysts, are highly compatible with water and thereby offer great potential as chiral catalysts for multicomponent protocols that unavoidably release water molecules during the course of the reaction.We present a detailed investigation of several MCRs catalyzed by chiral phosphoric acids, including Biginelli and Biginelli-like reactions; 1,3-dipolar cycloadditions; aza Diels-Alder reactions; and some other cyclization reactions. These approaches have enabled the facile preparation of 3,4-dihydropyrimidinones, pyrrolidines, piperidines, and dihydropyridines with high optical purity. The synthetic applications of these new protocols are also discussed, together with theoretical studies of the reaction transition states that address the regio- and stereochemistry. In addition, we briefly illustrate the application of a recently developed strategy that involves relay catalysis by a binary system consisting of a chiral phosphoric acid and a metal complex. This technique has provided access to new reactions that generate structurally diverse and complex heterocycles.Enantioselective organocatalytic MCRs remain a challenge, but we illustrate success on several fronts with chiral phosphoric acids as the primary catalysts. Further progress will undoubtedly provide even better access to the chiral nitrogen-containing heterocycles that are not only prevalent as natural products but also serve as key chiral building blocks in organic synthesis. © 2011 American Chemical Society.

Yang L.,Xuzhou Normal University | Xu L.,Yangzhou University
Information Sciences | Year: 2011

Rough set theory is a powerful mathematical tool for dealing with inexact, uncertain or vague information. The core concepts of rough set theory are information systems and approximation operators of approximation spaces. Approximation operators draw close links between rough set theory and topology. This paper concerns generalized approximation spaces via topological methods and studies topological properties of rough sets. Classical separation axioms, compactness and connectedness for topological spaces are extended to generalized approximation spaces. Relationships among separation axioms for generalized approximation spaces and relationships between topological spaces and their induced generalized approximation spaces are investigated. An example is given to illustrate a new approach to recover missing values for incomplete information systems by regularity of generalized approximation spaces. © 2011 Elsevier Inc. All rights reserved.

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