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MULTIVALUED PERTURBATION TO NONLINEAR DIFFERENTIAL INCLUSIONS WITH MEMORY IN BANACH SPACES

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Chinese Annals of Mathematics,Series B 1996年第2期17卷 237-244页

作者： XUEXINGMEI SONGGUOZHU departmentofMathemtics＆Mechanics SoutheastUniversityNanjing210018China. departmentofMathematics NanjingUniversityNanjing210008China.

The authors give the existence results to the nonlinear differential inclusion u'(t) ∈ Au(t) +F(t,ut), where A is a ganerator of equicontinuous semigroup and F is multivalued.

关键词： Differential inclusion with memory Equicontimuous semigroup Housdorff measure Kamke function

On the Conditions of a Center and General Integrals of Quadratic Differential Systems

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Acta Mathematica Sinica,English Series 2001年第2期17卷 229-236页

作者： Wei Yin YE department of Mathematics. nanjing Normal {2.. nanjing 2.0097, P. R. china Yan Qian YE department of Mathematics. nanjing university, nanjing 2.0093, P. R. china department of Mathematics Nanjing Normal University Nanjing 210097 P. R. China department of Mathematics Nanjing University Nanjing 210093 P. R. China

We give the general integral of quadratic differential system with center in two cases under the Chinese classification.

关键词： Quadratic differential system Center General integral

A RESTRICTED TRUST REGION METHOD WITH SUPERMEMORY FOR UNCONSTRAINED OPTIMIZATION

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Journal of Computational Mathematics 1996年第3期14卷 195-202页

作者： L.P. Sun(department of Mathematics, nanjing university, Jiangsu,{2.) nanjing UNIV DEPT MATHJIANGSUPEOPLES R CHINA

A new method for unconstrained optimization problems is presented. It belongs to the class of trust region method, in which the descent direction is sought by using the trust region steps within the restricted subspace. Because this subspace can be specified to include information about previous steps, the method is also related to a supermemory descent method without performing multiple dimensional searches. Trust region methods have attractive global convergence property. Supermemory information has good scale independence property. Since the method possesses the characteristics of both the trust region methods and the supermemory descent methods, it is endowed with rapidly convergence. Numerical tests illustrate this point.

关键词： TF Math RTR

Robust adaptive backstepping control for a class of uncertain nonlinear systems based on disturbance observers

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Science china(Information Sciences) 2010年第6期53卷 1201-1215页

作者： MEI Rong 1,2. WU QingXian 1 & JIANG ChangSheng 1 1 Automation College, nanjing university of Aeronautics and Astronautics, nanjing 2.0016,{2. 2.Criminal Investigation department, nanjing Forest Police College, nanjing 2.0042.{2. 1. Automation College Nanjing University of Aeronautics and Astronautics Nanjing 210016 China2. Criminal Investigation Department Nanjing Forest Police College Nanjing 210042 China

In this paper, a novel robust adaptive control scheme for a class of uncertain nonlinear systems is proposed using disturbance observer and backstepping ***, a disturbance observer is developed using radial basis function(RBF) neural *** parameter updated law of the RBF neural network is given for monitoring subsystem disturbance *** robust adaptive control scheme is then presented with backstepping method based on the designed disturbance *** uniform ultimate boundedness(SGUUB) of all signals in the closed-loop uncertain nonlinear system is *** closed-loop system stability analysis shows that semiglobal uniform boundedness of all signals is guaranteed by appropriately choosing design ***, two examples are taken to illustrate the effectiveness of the proposed control scheme.

关键词： uncertain nonlinear systems disturbance observer RBF neural network backstepping control robust adaptive control

Molecular dynamics simulation of mechanical properties of TATB/fluorine-polymer PBXs along different surfaces

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Science china Chemistry 2005年第6期48卷 504-510页

作者： XIAO Jijun1, HUANG Yucheng1, HU Yingjie1,2.& XIAO Heming1 1. department of Chemistry, nanjing university of Science and Technology, {2. 2.0094, china 2. department of Chemistry, {2. Xiaozhuang College, {2. 2.0017, china Correspondence should be addressed to Xiao Heming (email: xiao@***) 1. department of Chemistry Nanjing University of Science and Technology 210094 Nanjing China 2. department of Chemistry Nanjing Xiaozhuang College 210017 Nanjing China

The mechanical properties of PBXs composed of the well-known insensitive explo-sive TATB (1,3,5-Triamino-2.4,6-trinitrobenzene) crystal and four kinds of typical fluo-rine-polymers, i.e. poly (vinylidene difluoride) (PVDF), polychlorotrifluoroethylene (PCTFE), fluo-rine rubber (F2.11) and fluorine resin (F2.14) individually, have been simulated by molecular dy-namics (MD) method. The results show that the mechanical properties of TATB can be effectively improved by blending with a small amount of fluorine-polymers. Different mechanical properties of PBXs are obtained by putting fluorine-polymer binders parallel to different crystalline surfaces. The whole effect of improving mechanical properties is found to be (010)?(100)>(001).

关键词： TATB, polymer bonded explosives, mechanical properties, molecular dynamics.

Effect of Conversion Efficiency on Gamma-Ray Burst Energy

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Chinese Journal of Astronomy and Astrophysics 2004年第3期4卷 267-274页

作者： Lei Xu Zi-Gao Dai department of Astronomy nanjing university{2. department of Astronomy Nanjing University Nanjing 210093

Beaming effect makes it possible that gamma-ray bursts have a standardenergy, but the gamma-ray energy release is sensitive to some parameters. Our attention is focusedon the effect of the gamma ray conversion efficiency (η_γ), which may range between 0.01 and 0.9,and which probably has a random value for different GRBs under certain conditions. Making use of theafterglow data from the literature, we carried out a complete correction to the conical openingangle formula. Within the framework of the conical jet model, we ran a simple Monte Carlo simulationfor random values of η_γ, and found that the gamma-ray energy release is narrowly clustered,whether we use a constant value of η_γ or random values for different gamma-ray bursts.

关键词： gamma rays: bursts ISM: jets

Galactic kinematics and structure defined by open clusters

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Research in Astronomy and Astrophysics 2009年第12期9卷 1285-1302页

作者： Zi Zhu department of Astronomy Nanjing University Nanjing 210093 China

On the basis of recently published astrophysical parameters of the open clusters, we have selected 301 clusters with measurements of their kinematical parameters to trace the local structure and kinematics of the Galactic disk. The present sample covers a range of over 3.0 kpc from the Sun and gives significant estimates of the disk structure and kinematical parameters of the Galaxy. We derive the disk scale height, vertical displacement of the Sun to the Galactic plane, solar motion with respect to the local standard of rest, circular speed of the Galactic rotation, Galactocentric distance from the Sun, etc. We found that the average scale height of the disk defined by the open clusters is Zh = 58 ± 4pc, with a vertical displacement of the Sun below the Galactic plane of z0 -= - 16±4 pc. Clusters with ages older than 50 Myr are less concentrated in the average plane （Zh=67 ±6pc） than the younger clusters （Zh = 51±5pc）. Using the approximation of axisymmetric circular rotation, we have derived the distance to the Galactic center from the Sun R0 = 8.03 ±0.70 kpc, which is in excellent agreement with the best estimate of the Galactocentric distance. From a kinematical analysis, we found an agedependent rotation of the Galaxy. The older clusters exhibit a lower velocity of vorticity, but have the same shear as the younger clusters. The mean rotation velocity of the Galaxy was obtained as 2.5 ± 10 km s-1.

关键词： Galaxy: disk -- Galaxy: kinematics and dynamics -- Galaxy: open clustersand associations: general -- Galaxy: structure

PRIMAL PERTURBATION SIMPLEX ALGORITHMS FOR LINEAR PROGRAMMING

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Journal of Computational Mathematics 2000年第6期18卷 587-596页

作者： Ping-qi Pan (department of Applied Mathematics, Southeast university, {2. 2.0096, china.) 东南大学江苏南京 210096

In this paper, we propose two new perturbation simplex variants. Solving linear programming problems without introducing artificial variables, each of the two uses the dual pivot rule to achieve primal feasibility, and then the primal pivot rule to achieve optimality. The second algorithm, a modification of the first, is designed to handle highly degenerate problems more efficiently. Some interesting results concerning merit of the perturbation are established. Numerical results from preliminary tests are also reported. [ABSTRACT FROM AUTHOR]

关键词： linear programming perturbation primal simplex algorithm partially revised tableau

Tribological Properties of Dimpled Surface Alloying Layer on Carbon Steel

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Journal of Wuhan university of Technology(Materials Science) 2009年第2期24卷 218-222页

作者：万轶 department of Materials Science & Engineering Nanjing University of Science and Technology department of Mechanical and Electrical Engineering Yingtian College

The effect of surface structure and coating on tribological properties of 45^# carbon steel disc was analyzed. A Nd：YAG laser was used to generate rnicrodirnples on steel surfaces. Dimples with diameter of 150 rn and depth of 50 rn were distributed in an orbicular array on disc surface. Then the alloying element Mo was sputtered to 45# carbon steel disc surface by means of double glow plasma technology. Diffusion Mo alloying layer with 30min thickness and high hardness up to 0.02. was formed on the disc surface. Tribological experiments of three types samples （smooth, texturing and texturing＋alloying） were conducted with a pin-on-disc tribometer. It is found that the dimpled-samples are most effective for reducing friction in comparison with smooth steel surthces, improving the lubricating state from boundary to hydrodynamic region.

关键词： laser surface texturing double glow plasma surface alloying technology carbon steel tribological performance lubricating state