检索结果-南通市图书馆

Positive Solutions to m-point Boundary Value Problem of Fractional Differential Equation

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2013年第3期29卷 661-672页

作者： Yuan-sheng tian Department of Mathematics Xiangnan University

In this paper, we study the multiplicity of positive solutions to the following m-point boundary value problem of nonlinear fractional differential equations： Dqu（t）＋ f（t, u（t）） = 0, 0 t 1, u（0） = 0, u（1） =sum （μiDpu（t）｜t = ξi ） from i =1 to ∞ m-2, where q ∈R , 1 q ≤2 , 0 ξ1 ξ2 ··· ξm-2 ≤ 1/2 , μi ∈[0 , ＋∞） and p = q-1/2 , Γ（q） sum （μiξi（q-1）/2 Γ（（ q＋1）/2） from i =1 to ∞ m-2,Dq is the standard Riemann-Liouville differentiation, and f ∈C （[0 , 1]×[0 , ＋∞） , [0 , ＋∞））. By using the Leggett-Williams fixed point theorem on a convex cone, some multiplicity results of positive solutions are obtained.

关键词： fractional differential equation m-point boundary value problem fixed-point theorem positive solutions

Research and Application of Dynamic Equation for Full Frontal Impact

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2015年第3期22卷 101-106页

作者： sheng tian School of Civil Engineering and Transportation South China University of Technology

Full frontal impact theory needs researching and exploring to satisfy the primary safety design of occupant restraint system,avoiding the increasingly "engineering"trend in order to develop and design safety vehicle. After occupant restraint system is simulated by using linear elastic stiffness k,the occupant-vehicle frontal rigid barrier impact model is established. Dynamic equation of dummy chest coupling vehicle is built for full frontal impact based on ordinary vehicle deceleration by Hooke law,and the equation is solved by comparing coefficient and satisfying boundary qualifications. While relative vehicle characteristic parameters are kept unchanging,the actual vehicle deceleration is fitted to the simplified equivalent square wave( ESW),tipped equivalent square wave( TESW) and equivalent dual trapezoids wave( EDTW). Phase angle  and amplitude A of dynamic equations based on ESW,TESW and EDTW are calculated and deduced. The results show that: the dynamic equation of dummy chest coupling vehicle can be well utilized to instruct the primary safety design of full frontal impact for objective vehicle to satisfy chest deceleration demands and the equation based on TESW is best for this design.

关键词： vehicle engineering full frontal impact dynamic equation deceleration simplified wave occupant restraint system

Integrating potential distribution of dominant vegetation and land use into ecological restoration in the Yellow River Basin,China

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2022年第10期19卷 2886-2904页

作者： JIAN sheng-qi ZHU tian-sheng HU Cai-hong College of Water Resources and Environment Zhengzhou UniversityZhengzhou 450001China

Due to the influence of human activities such as cultivation and urban construction,the ecosystem of the Yellow River Basin(YRB)is subjected to increased vulnerability and even potential risk of *** restoration has led to an increase in vegetation,but excessive afforestation conversely results in low survival rate of trees,water shortages,and biodiversity *** is of great significance for achieving sustainable development of forests to reasonable revegetation in the *** present,the potential distribution pattern of dominant species and their mixed forms in the basin has not been effectively *** study simulated the potential distribution of dominant vegetation in the YRB based on Maximum Entropy(Max Ent)and Genetic Algorithm for Rule-Set Prediction(GARP)and explored the impact of human interference on it by employing land use as the environmental filter to distinguish the regions of human *** further predicted the potential distribution of typically mixed forests and discussed their human *** main results are as follows:(1)Except for Caragana korshinskii,all models had good above performance(0.7

关键词： Yellow River Potential distribution Land use Mixed forests Vegetation restoration

Multiplicity of Positive Solutions to M-point Boundary Value Problem of Second Order Impulsive Differential Equations

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2010年第1期26卷 145-158页

作者： Yuan-sheng tian Chun-gen Liu Department of Mathematics Xiangnan University Chenzhou 423000 China School of Mathematics and LPMC Nankai University Tianjin 300071 China

In this paper, by using Avery-Peterson theorem on a convex cone, we consider the m-point boundary value problems for second order impulsive differential equations with the nonlinear term depending on the first order d... 详细信息

关键词： Boundary value problem impulsive differential equations fixed-point theorem positive solutions

ADHESIVE CONTACT PROBLEM OF AXISYMMETRIC MINIATURE CIRCULAR PLATES WITH CENTRAL RIGID BUMP

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2006年第4期19卷 341-351页

作者： Fu Yiming Li sheng tian Yanping Department of Engineering Mechanics Hunan University Changsha 410082 China

Considering the adhesive effect and geometric nonlinearity, the adhesive contact between an elastic substrate and a clamped miniature circular plate with two different central rigid bumps under the action of uniform transverse pressure and in-plane tensile force in the radial direction was analyzed. And an analytical solution is presented by using the perturbation method. The relation of surface adhesive energies with critical load to detach the contacted surfaces is obtained. In the numerical results, the effects of adhesive energy, in-plane tensile force, rigid bump size and contact radius on the critical load are discussed, and the relation of critical contact radius with the gap between the central rigid bump and the substrate for different adhesive energies is investigated.

关键词： miniature hesive contact geometric circular plate two different central rigid bumps elastic substrate adnonlinearity

Flag-transitive point-primitive 2-(v,k,4) symmetric designs and two dimensional classical groups

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2011年第3期26卷 334-341页

作者： ZHOU sheng-lin tian De-lu Department of Mathematics South China University of Technology Guangzhou 510640 China

Let D be a 2-（v, k, 4） symmetric design and G be a flag-transitive point-primitive automorphism group of D with X ≥G ≤Aut（X） where X ≌ PSL2（q）.Then D is a 2-（15,8,4） symmetric design with X = PSL2（9） and ... 详细信息

关键词： Symmetric design flag-transitive point-primitive two dimensional classical group.

Bosonic Halperin(441)Fractional Quantum Hall Effect at Filling Factorν=2/5

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2022年第1期39卷 21-26页

作者： tian-sheng Zeng Liangdong Hu WZhu Department of Physics School of Physical Science and TechnologyXiamen UniversityXiamen 361005China Zhejiang University Hangzhou 310027China School of Science Westlake UniversityHangzhou 310024China Key Laboratory for Quantum Materials of Zhejiang Province School of ScienceWestlake UniversityHangzhou 310024China

Quantum Hall effects with multicomponent internal degrees of freedom facilitate the playground of novel emergent topological ***,we explore the correlated topological phases of two-component hardcore bosons at a total filling factorν=2/5 in topological lattice models under the interplay of intracomponent and intercomponent *** give the numerical demonstration of the emergence of Halperin(441)fractional quantum Hall effect based on exact diagonalization and density-matrix renormalization group *** elucidate its topological features including the degeneracy of the ground state,fractionally quantized topological Chern number matrix and chiral edge modes.

关键词： methods. topological fractional

A New Monodisperse Reactive Resin with Active Groups on the Particle Surface

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2001年第1期12卷 71-72页

作者： Yu Han GUO tian sheng SU Center for Molecule Science Institute of ChemistryThe Chinese Academy of SciencesBeijing 100080

A novel reactive resin as active support was synthesized by an improved method based on seed swelling and surface coating polymerization. The resin is monosized beads with inner nucleus of cross-linked polymer and sur... 详细信息

关键词： Monosized polymer beads reactive resin active support

Synthesis and Crystal Structure of a New Glycinato Copper Compound

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2006年第5期25卷 631-635页

作者： XIANG sheng-Chang sheng tian-Lu FU Rui-Biao HU sheng-Min WU Xin-Tao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter The Chinese Academy of Sciences Fuzhou Fujian 350002 China

A glycinato copper compound {Cu（NH2CH2COO）（H2O）ClO4} crystallizes in monoclinic, space group P21/n with a = 7.8299（9）, b = 10.3807（10）, c = 9.4775（12）A, β = 109.659（6）°, V = 725.43（12）A^3, Z = 4, Mr = 255.07, Dc = 2.335 g/cm^3, F（000） = 508,μ = 3.381 mm^-1, R = 0.0270 and wR = 0.0707 for 1677 observed reflections with Ⅰ 〉 2σ（Ⅰ）. The title compound contains a chain in the syn-anti conformation, which is generated by the glide-plane operation. The adjacent layers made up of the chains through the connection of perchlorate are related by inversion center operation, which links with each other through the hydrogen bonds.

关键词： glycinato copper complex chain hydrogen bonds