检索结果-南通市图书馆

science china mathematics 2007年第7期50卷 1055-1064页

作者： Bao-xing CHEN~(1+) Xie-bin CHEN~2 Ji-xiang MENG~3 Wen-jun XIAO~4 1 Department of Computer science,Zhangzhou Teachers college,Zhangzhou 363000,china 2 Department of mathematics and Information science,Zhangzhou Teachers college,Zhangzhou 363000,china 3 college of mathematics & system science,xinjiang university,urumqi 830046,china 4 Department of Computer science,South china university of Technology,Guangzhou 510641,china 1. Department of Computer science Zhangzhou Teachers College Zhangzhou 363000 China 2. Department of mathematics and Information science Zhangzhou Teachers College Zhangzhou 363000 China 3. college of mathematics & system science Xinjiang University Urumqi 830046 China 4. Department of Computer science South China University of Technology Guangzhou 510641 China

The double loop network(DLN)is a circulant digraph with n nodes and outdegree *** is an important topological structure of computer interconnection networks and has been widely used in the designing of local area networks and distributed *** the number n of nodes,how to construct a DLN which has minimum diameter?This problem has attracted great attention.A related and longtime unsolved problem is:for any given non-negative integer k,is there an infinite family of k-tight optimal DLN?In this paper,two main results are obtained:(1)for any k≥0,the infinite families of k-tight optimal DLN can be constructed,where the number n(k,e,c)of their nodes is a polynomial of degree 2 in e with integral coefficients containing a parameter c.(2)for any k≥0, an infinite family of singular k-tight optimal DLN can be constructed.

关键词： double loop network diameter k-tight optimal singular k-tight optimal 05C12 05C20 05C85

Optimal error bound of restricted Monte Carlo integration on anisotropic Sobolev classes

在线全文

学校读者我要写书评

暂无评论

Progress in Natural science:Materials International 2006年第6期16卷 588-593页

作者： GAO Wenhua, YE Peixin and WANG Hui (college of mathematics and system sciences, xinjiang university, urumqi 830046, china School of Mathematical sciences and LPMC, Nankai university, Tianjin 300071, china Department of mathematics, Ily Teachers' college, Yining 835000, china college of science, Hehai university, Nanjing 210098, china) [a]college of mathematics and system sciences Xinjiang University Urumqi China [b]School of Mathematical sciences and LPMC Nankai University Tianjin China [c]Department of mathematics Ily Teachers College Yining China [d]college of science Hehai University Nanjing China

We study the restricted Monte Carlo integration error for anisotropic Sobolev classes. Results prove that with O(log2 n) random bits we have the optimal order for the n-th minimal Monte Carlo integration error with ar... 详细信息

关键词： Monte Carlo integration random bits anisotropic Sobolev classes.

Electrochemical synthesis of ammonia using a cell with a Nafion membrane and SmFe_(0.7)Cu_(0.3-x)Ni_xO_3(x=0―0.3) cathode at atmospheric pressure and lower temperature

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science china Chemistry 2009年第8期52卷 1171-1175页

作者： XU GaoChao,LIU RuiQuan & WANG Jin college of Chemistry and Chemical Engineering,xinjiang university,urumqi 830046,china college of Chemistry and Chemical Engineering Xinjiang University Urumqi 830046 China

Samaria-doped ceria Ce0.8Sm0.2O2-δ(SDC) and SmFe0.7Cu0.3-xNixO3 have been synthesized by the sol-gel method and characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM) and scanning electron microscopy(SEM).The electrochemical synthesis of ammonia was investigated at atmospheric pressure and low temperature,using the SFCN materials as the cathode,a Nafion membrane as the electrolyte,nickel-doped SDC(Ni-SDC) as the anode and silver-platinum paste as the current *** was synthesized from 25 to 100℃ when the SFCN materials were used as cathode,with SmFe0.7Cu0.1Ni0.2O3 giving the highest rates of ammonia *** maximum rate of evolution of ammonia was 1.13 × 10-8 mol·cm-2·s-1 at 80℃,and the current efficiency reached as high as 90.4%.

关键词： electrochemical synthesis of ammonia ammonia synthesis at atmospheric pressure and low temperature Nafion membrane metal oxide

Biomimetic soft robotic wrist with 3-DOF motion and stiffness tunability based on ring-reinforced pneumatic actuators and a particle jamming joint

在线全文

学校读者我要写书评

暂无评论

science china(Technological sciences) 2024年第3期67卷 774-790页

作者： HU TeTe LU xinjiang YI Jian WANG YuHui XU Du State Key Laboratory of Precision Manufacturing for Extreme Service Performance School of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The human wrist, a complex articulation of skeletal muscles and two-carpal rows, substantially contributes to improvements in maneuverability by agilely performing three-degree-of-freedom(3-DOF) orienting tasks and regulating stiffness according to variations in interaction forces. However, few soft robotic wrists simultaneously demonstrate dexterous 3-DOF motion and variable stiffness;in addition, they do not fully consider a soft-rigid hybrid structure of integrated muscles and two carpal *** this study, we developed a soft-rigid hybrid structure to design a biomimetic soft robotic wrist(BSRW) that is capable of rotating in the x and y directions, twisting around the z-axis, and possessing stiffness-tunable capacity. To actuate the BSRW, a lightweight soft-ring-reinforced bellows-type pneumatic actuator(SRBPA) with large axial, linear deformation(η_(lcmax)=70.6%,η_(lemax)=54.3%) and small radial expansion(η_(demax)=3.7%) is designed to mimic the motion of skeletal muscles. To represent the function of two-carpal rows, a compact particle-jamming joint(PJJ) that combines particles with a membrane-covered ballsocket mechanism is developed to achieve various 3-DOF motions and high axial load-carrying capacity(>60 N). By varying the jamming pressure, the stiffness of the PJJ can be adjusted. Finally, a centrally positioned PJJ and six independently actuated SRBPAs, which are in an inclined and antagonistic arrangement, are sandwiched between two rigid plates to form a flexible,stable, and compact BSRW. Such a structure enables the BSRW to have a dexterous 3-DOF motion, high load-carrying ability,and stiffness tunability. Experimental analysis verify 3-DOF motion of BSRW, producing force of 29.6 N and 36 N and torque of2.2 Nm in corresponding rotations. Moreover, the range of rotational angle and stiffness-tuning properties of BSRW are studied by applying jamming pressure to the PJJ. Finally, a system combining a BSRW and a soft enclosing gripper is proposed to demo

关键词： pneumatic soft actuators particle jamming robotic wrist soft robotics stiffness-tunable

Local electronic structure and magnetic properties of 3d transition metal doped GaAs

在线全文

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2008年第5期51卷 470-480页

作者： LIN He1 & DUAN HaiMing21 Department of Chemistry,Institute of Applied Chemistry,xinjiang university,urumqi 830046,china 2Department of Physics,xinjiang university,urumqi 830046,china 1. Department of Chemistry Institute of Applied Chemistry Xinjiang University Urumqi 830046 China 2. Department of Physics Xinjiang University Urumqi 830046 China

The local electronic structure and magnetic properties of GaAs doped with 3d transition metal (Sc, Ti, V, Cr, Mn, Fe, Co, Ni) were studied by using discrete variational method (DVM) based on density functional theory. The calculated result indicated that the magnetic moment of transition metal increases first and then decreases, and reaches the maximum value when Mn is doped into GaAs. In the case of Mn concentration of 1.4%, the magnetic moment of Mn is in good agreement with the experimental result. The coupling between impure atoms in the system with two impure atoms was found to have obvious variation. For different transition metal, the coupling between the impure atom and the nearest neighbor As also has different variation.

关键词： diluted magnetic semiconductor density functional theory 3d transition metal cluster model electronic structure

A NOTE ON THE PAPER “UNIFORM PERSISTENCE IN DISCRETE SEMIDYNAMICAL system AND ITS APPLICATION”

在线全文

学校读者我要写书评

暂无评论

systems science and Mathematical sciences 1999年第2期12卷 145-148页

作者： TENG Zhidong(Department of mathematics, xinjiang university, urumqi 830046, china) 新疆大学数学系新疆乌鲁木齐

In this paper, we study the uniform persistence of a class of two dimensional periodic Kolmogorov ecosystems. As an improvement on a main result in [1] we obtain a new criterion of the uniform persistence for solutions.

关键词： Kolmogorov system periodic uniform persistence unbounded ultimate bound.

TIME-DEPENDENT COOPERATIVE system OFPOPULATION GROWTH

在线全文

学校读者我要写书评

暂无评论

systems science and Mathematical sciences 1998年第3期11卷 204-209页

作者： CUI Jingan DUAN Kuichen(Department of mathematics, xinjiang university, urumqi 830046, china) 新疆大学数学系新疆乌鲁木齐

In this paper, we consider the asymptotic behavior of a general time-dependent cooperative system. Sufficient condition is obtained for the existence of a globally attractive positive periodic solution when the system... 详细信息

关键词： Cooperative system globally attractive periodic solution Poincare mapping

LEAST-SQUARES MIXED FINITE ELEMENT METHODS FOR NONLINEAR PARABOLIC PROBLEMS

在线全文

学校读者我要写书评

暂无评论

Journal of Computational mathematics 2002年第2期20卷 153-164页

作者： Dan-ping Yang (School of mathematics and system science, Shandong university, Jinan 250100, china) School of mathematics and system science Shandong University Jinan 250100

Focuses on the formulation of a number of least-squares mixed finite element schemes to solve the initial boundary value problem of a nonlinear parabolic partial differential equation. Convergence analysis; Informatio... 详细信息

关键词： least-squares algorithm mixed finite element nonlinear parabolic problems convergence analysis

Infinite Circulant Digraphs and Random Infinite Circulant Digraphs

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2002年第4期18卷 817-822页

作者： Qiang Xiang HUANG Ji Xiang MENG The college of mathematics and sciences. xinjiang university. urumqi 830046. P. R. china Fu Ji ZHANG The Department of mathematics. Xiamen university. Xiamen 301005. P. R. china The college of mathematics and sciences Xinjiang University Urumqi 830046 P. R. China The Department of mathematics Xiamen University Xiamen 361005 P. R. China

In this paper, we completely determine the connectivity of every infinite circulant digraphs and prove that almost all infinite circulant digraphs are infinitely strongly connected and therefore have both one-and two-... 详细信息

关键词： Infinite circulant digraph Connectivity Hamiltonian path

Weighted Estimates for Marcinkiewicz Integrals with Non-Doubling Measures

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical Research with Applications 2012年第2期32卷 223-234页

作者： Songbai WANG,Yinsheng JIANG,Baode LI college of mathematics and system sciences,xinjiang university,xinjiang 830046,P.R.china college of mathematics and system sciences Xinjiang University Xinjiang 830046

Let μ be a nonnegative Radon measure on R d which satisfies the growth condition μ(B(x,r)) ≤ C0rn for all x ∈Rd and r >0,where C0 is a fixed constant and 0 详细信息

Let μ be a nonnegative Radon measure on R d which satisfies the growth condition μ(B(x,r)) ≤ C0rn for all x ∈Rd and r >0,where C0 is a fixed constant and 0

关键词： maximal singular integrals Muckenhoupt type weights sharp maximal operators non-doubling measures.