Labelling of some planar graphs with a condition at distancetwo

Sumei Zhang,Qiaoling Ma 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.24 No.1

LABELLING OF SOME PLANAR GRAPHS WITH A CONDITION AT DISTANCE TWO

Zhang, Sumei,Ma, Qiaoling 한국전산응용수학회 2007 Journal of applied mathematics & informatics Vol.24 No.1

The problem of vertex labeling with a condition at distance two in a graph, is a variation of Hale's channel assignment problem, which was first explored by Griggs and Yeh. For positive integer $p{\geq}q$, the ${\lambda}_{p,q}$-number of graph G, denoted ${\lambda}(G;p,q)$, is the smallest span among all integer labellings of V(G) such that vertices at distance two receive labels which differ by at least q and adjacent vertices receive labels which differ by at least p. Van den Heuvel and McGuinness have proved that ${\lambda}(G;p,q){\leq}(4q-2){\Delta}+10p+38q-24$ for any planar graph G with maximum degree ${\Delta}$. In this paper, we studied the upper bound of ${\lambda}_{p,q}$-number of some planar graphs. It is proved that ${\lambda}(G;p,q){\leq}(2q-1){\Delta}+2(2p-1)$ if G is an outerplanar graph and ${\lambda}(G;p,q){\leq}(2q-1){\Delta}+6p-4q-1$ if G is a Halin graph.

Preparation of Tunable Emissive Poly(ethylene oxide) Nanofibers by Doping with TPP and DCM

Lianji Zhang,이연식,Dongri Zhang,Sumei Zhan,Peipei Yang,Guixia Yang,Zonghao Huang 한국고분자학회 2012 Macromolecular Research Vol.20 No.2

Poly(ethylene oxide) (PEO) nanofibers that were doubly-doped with a donor, 1,3,5-triphenyl-2-pyrzoline (TPP), and an acceptor, 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl-aminostyryl)-4H-pyran (DCM), were prepared by electrospinning to be 200-300 nm in diameter. Fluorescence from DCM was caused by non-radiative Forster-type fluorescence resonance energy transfer from photo-excited TPP to DCM. The color of the fluorescence from the PEO-TPP/DCM nanofibers was controllable through variation of the TPP:DCM molar ratio and ranged from blue to orange to white.

High-performance Zinc-Tin-Oxide thin film transistors based on environment friendly solution process

Qian Zhang,Guodong Xia,Lubin Li,Wenwen Xia,Hong-Yu Gong,Sumei Wang 한국물리학회 2019 Current Applied Physics Vol.19 No.2

Zinc-Tin-Oxide (ZTO) thin films were fabricated using a simple and eco-friendly sol-gel method and their application in thin film transistors (TFTs) was investigated. Annealing temperature has a crucial influence on the structure and electrical properties of sol-gel ZTO thin films. The ZTO thin films annealed at 300–600 °C revealed smooth and uniform surfaces with amorphous state, in addition, a high optical transparency over 90% of the ZTO films in the visible range was obtained. The electrical performance of ZTO TFTs showed obvious dependence on annealing temperature. The ZTO TFTs annealed at 500 °C showed a high carrier mobility of 5.9 cm2 /V, high on/off current ratio (Ion/off) of 106 -107 , and threshold voltage (Vth) of 1.03 V. To demonstrate the application of sol-gel ZTO films in low-power display fields, we also fabricated ZTO TFTs with a solution-processed high-permittivity (high-k) ZrTiOx dielectric layer. The ZTO/ZrTiOx TFTs showed high mobility of 17.9 cm2 /V and Ion/off of 105 -106 at a low operation voltage of 3 V, indicating that Indium-free ZTO thin films would be potential candidates for low cost, high performance oxide TFT devices.

Simulation of Tensile Bolts in Finite Element Modeling of Semi-rigid Beam-to-column Connections

Zhaoqi Wu,Sumei Zhang,Shao-Fei Jiang 한국강구조학회 2012 International Journal of Steel Structures Vol.12 No.3

This paper presents an innovative bolt model suitable for the three dimensional finite element analysis (FEA) of the semirigid beam-to-column bolted connections. The model is particularly useful for the moment-rotation relationship of beam-tocolumn connections, especially in cases where the connectors such as endplates, angles, T-stubs, are not particularly thin. In this paper, the bolt tensile behavior is firstly discussed by using a refined finite element model, in which the complex geometries of both external and internal threads were modeled. Then, the bolt behavior predicted by the commonly used models was compared with that of the refined FEA to appraise the accuracy of these models. The comparison shows most of the models commonly used can not predict accurately the axial stiffness, carrying capacity and ductility of bolt simultaneously. Afterwards,an innovative bolt model was proposed and the model accorded with the refined FEA for single bolts. Finally, the proposed model was applied to analyze the moment-rotation behavior of several experimented and well documented connections with different configurations. The results indicate that the proposed model is feasible and efficient.

Geochemistry, zircon U-Pb ages and Sr-Nd-Hf isotopes of an Early Triassic appinitic complex in southeastern Inner Mongolia, China: implications for the late tectonic evolution of the Paleo-Asian Ocean

Junbin Zhu,Sumei Zhang 한국지질과학협의회 2020 Geosciences Journal Vol.24 No.6

Appinite commonly occurs in convergent plate tectonic settings and thus can constrain the tectonic evolution of ancient orogens. Geochemical and geochronological analyses were carried out on a newly identified Early Triassic appinitic complex in southeastern Inner Mongolia in the eastern segment of the Central Asian Orogenic Belt. Petrographically, the Luotuochang complex can be divided into two zones: an outer zone of intermediate rocks and inner zone dominated by mafic rocks. A monzonite sample from the outer zone yielded weighted mean zircon 206Pb/238U ages of 246 ± 1.6 Ma, whereas the gabbro from the inner zone yielded an age of 243 ± 1.2 Ma. The inner zone mafic rocks have SiO2 contents of 45.56 to 54.27 wt% with high MgO, Cr, Ni and Sr contents, elevated Ba/Nb, Ba/Zr, Rb/Y and Th/Zr, and low TiO2, Nb/Zr and Nb/Y. These features suggest that the metasomatized lithospheric mantle is the primitive magma source. SiO2 contents of the outer zone intermediate rocks range from 57.6 to 63.69 wt% and K2O, Ba and Sr contents are enriched; the εNd(t) (+2.2 to +4.0) and εHf(t) (+8.4 to +13.5) values are also high. These characteristics suggest that the magma of these rocks mainly derived from the mantle with possible juvenile lower crust involvement. Based on these geochemical data and results from regional geological investigations, we propose that the Luotuochang appinitic complex was formed in a post-orogenic extensional setting. Its formation was likely the result of lithospheric delamination, upwelling of new mantle material and partial melting of the overlying lower crust during crustal compression and thickening soon after the closure of the restricted Paleo-Asian Ocean basin.

Hysteretic Behavior of Reinforced Concrete Columns Confined By Square Steel Tubes.

Xiaoyong Wang(왕소용),Sumei Zhang(장수메이),Lee, Han-Seoung(이한승) 한국콘크리트학회 2006 한국콘크리트학회 학술대회 논문집 Vol.2006 No.5

Experimental Study and Numerical Analysis on Heavy-Duty Cast Steel Universal Hinged Supports for Large Span Structures

Yuyin Wang,Chao Gong,Sumei Zhang,Haishan Guo 한국강구조학회 2010 International Journal of Steel Structures Vol.10 No.1

Heavy-duty cast steel universal hinged supports are gaining increasing usage in modern large-span structures, offering extremely large individual load carrying capacity and universal rotation ability which is preferable to release temperature effects and to improve force conditions of lower structures. This paper presents a full-scale experimental study and elastic-plastic finite element (FE) analysis on the performance of an innovative heavy-duty cast steel support. The support is composed of three main components, i.e. an upper one, a lower one and an intermediate rotation pad. External loads are designed to be passed and transferred through the contact interaction of the three casting parts. The support studied in this paper is expected to possess a higher capacity than existing supports while having the ability of universal rotation under heavy loads. Three full-scale static experiments corresponding to three typical load cases (i.e. tension-shear load case, compression-shear load case, and sheartension load case, respectively) have been carried out employing a multifunctional loading device. A three-dimensional FE model was developed using the commercial software ANSYS, considering the contact behavior between the support components and accounting for both material and geometrical nonlinearities. The model was validated against the experimental results reported in this paper. The performance of this support was evaluated in accordance with a Chinese national code ‘Technical specification for application of connections of structural steel casting (CECS 235:2008)’. This study concluded that this type of support performs well and that it could be used for realistic applications.

Compressive Behavior of T-shaped Concrete Filled Steel Tubular Columns

Hua Yang,Yuanlong Yang,Sumei Zhang 한국강구조학회 2010 International Journal of Steel Structures Vol.10 No.4

Special-shaped column structures improve residential architectural space, compared with traditional frame structures. However, in respect to applicable building height and seismic fortification intensity, traditional special-shaped reinforced concrete (RC) columns have strict limitations in seismic behavior, which hampers further generalization and application of special-shaped columns. Due to increase in constraint effect for concrete, special-shaped concrete-filled steel tube (CFST)columns are expected to behave advantages on the strength, ductility and seismic behavior over special-shaped RC columns. However, special attention should be paid to prevent the steel plates’ premature local buckling and the separation between steel tube and concrete at inner corners. The battlement-shaped bar stiffeners and tensile bar stiffeners, welded on tube surfaces, were first put forward in this paper. Experimental study of 9 stubs in three groups subjected to axial loads was conducted, and the specimens consist of 3 square stubs (including 1 non-stiffened and 2 stiffened CFST specimens) and 6 T-shaped stubs (including 1 RC specimen, 2 non-stiffened and 3 stiffened CFST specimens). Failure modes and static properties of the specimens were investigated. Experimental results reveal that: Due to the constraint effect provided by T-shaped tubes, the CFST specimens behave advantages on the RC specimen in the ascending stiffness, peak resistance and ductility (except for the battlementshaped bar stiffened CFSTs). For square and T-shaped stiffened CFST specimens, the stiffeners improve their ductility,especially the tensile bar which gives the best performance in ductility and improves the peak resistance substantially. The stiffeners postpone the buckling of tubes, and even upgrade the classification of composite sections, without thickening the tubes.

In-Plane Stability of Concrete-Filled Steel Tubular Parabolic Truss Arches

Changyong Liu,Qing Hu,Yuyin Wang,Sumei Zhang 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.4

For determining the in-plane buckling resistance of a concrete-fi lled steel tubular (CFST) arch, the current technical code GB50923-2013 specifi es the use of an equivalent beam-column method which ignores the eff ect of rise-to-span ratio. This may induce a gap between the calculated result and actual stability capacity. In this study, a FE model is used to predict the buckling behavior of CFST truss arches subjected to uniformly distributed loads. The infl uence of rise-to-span ratio on the capacity of truss arches is investigated, and it is found that the stability capacity reduces as rise-to-span ratio declines. Besides, the calculations of equivalent slenderness ratio for diff erent truss sections are made to consider the eff ect of shear deformation. Moreover, based on FE results, a new design equation is proposed to predict the in-plane strength of CFST parabolic truss arches under uniformly distributed loads.