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On adjacent-vertex-distinguishing total coloring of graphs

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Science China Mathematics 2005年第3期48卷 289-299页

作者： ZHANG Zhongfu, CHEN Xiang’en, LI Jingwen, YAO Bing, LU Xinzhong & WANG Jianfang College of Mathematics and Information Science, Northwest Normal university, lanzhou 730070, China Department of Computer, lanzhou Normal College, lanzhou 730070, China Institute of Applied Mathematics, lanzhou jiaotong university, lanzhou 730070, China College of Information and Electrical Engineering, lanzhou jiaotong university, lanzhou 730070, China Institute of Applied Mathematics, Chinese Academy of Sciences, Beijing 100080, China College of Mathematics and Information Science Northwest Normal University Lanzhou China Department of Computer Lanzhou Normal College Lanzhou China Institute of Applied Mathematics Lanzhou Jiaotong University Lanzhou China College of Information and Electrical Engineering Lanzhou Jiaotong University Lanzhou China Institute of Applied Mathematics Chinese Academy of Sciences Beijing China

In this paper, we present a new concept of the adjacent-vertex-distinguishing total coloring of graphs (briefly, AVDTC of graphs) and, meanwhile, have obtained the adjacent-vertex-distinguishing total chromatic number... 详细信息

关键词： graph, proper total coloring, adjacent-vertex-distinguishing total coloring, adjacent-vertex-distinguishing total chromatic number.

Differences between laminar convections through parallel plain planes with uniform wall temperature and heat flux in terms of process parameter

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Science China(Technological Sciences) 2010年第3期53卷 789-799页

作者： WANG LiangBi,LIN ZhiMin,WU Xiang&SONG KeWei School of Mechatronic Engineering,lanzhou jiaotong university,lanzhou 730070,China School of Mechatronic Engineering Lanzhou Jiaotong University Lanzhou China

Using the process parameter description,we analyzed the difference between the characteristics of laminar convections through parallel plain planes with uniform temperature and heat *** results show the following.(1)On the wall surface of the developing region,under uniform heat flux boundary condition,the heat flux normal to the wall surface is transported through a convection process although the velocity is zero;the velocity gradient contributes to this transport,but under uniform temperature boundary condition,the heat flux normal to the wall surface is transported through a difussion process.(2)Inside the flow of the developing region,whether under uniform temperature or heat flux boundary condition,the heat flux along the main flow direction and the heat flux normal to the wall surface are transported through a convection process,and the contributions of velocity and velocity gradient are dependent on the thermal boundary condition.(3)On the wall surface of the fully developed region,under uniform heat flux boundary condition,the heat flux normal to the wall surface is transported through a convection process;the velocity gradient contributes to this transport,but under uniform temperature boundary condition,the heat flux normal to the wall surface is transported through a diffusion process.(4)Inside the flow of the fully developed region,under uniform temperature boundary condition,the heat flux along the main flow direction and the heat flux normal to the wall surface are transported through a convection process,and the velocity and velocity gradient contribute to these transports;under uniform heat flux boundary condition,the heat flux along the main flow direction and the heat flux normal to the wall surface are transported through a convection ***,the transport of the heat flux along the main flow direction is a no-net convection process;the velocity gradient contributes to the transport of the heat flux only in the normal direction o

关键词： mechanism of convective heat transfer description of process parameter parallel plain planes uniform wall temperature uniform wall heat flux laminar flow

Improvements on voltage-resistant performance of bipolar static induction transistor (BSIT) with buried gate structure

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Science China(Information Sciences) 2012年第4期55卷 962-970页

作者： WANG YongShun,FENG JingJing,LIU ChunJuan,WANG ZiTing,WANG ZaiXing & ZHANG CaiZhen School of Electronic and Information Engineering,lanzhou jiaotong university,lanzhou 730070,China School of Electronic and Information Engineering Lanzhou Jiaotong University Lanzhou China

The breakdown mechanism of power bipolar static induction transistor (BSIT) with buried gate structure is analyzed in depth.A power BSIT sample with high voltage-resistant capability has been designed and fabricated in this *** technological methods for improving high voltage performances are *** active region of BSIT is surrounded with a deep trench to avoid any probable influences of various defects on device *** field-limiting ring-shape junctions and one channel termination ring-shape junction are arranged around the gate region to reduce the electric field *** gate-source breakdown voltage BV GS of power BSIT has been increased to 110 V from previous value of 50-60 V,and its blocking voltage is increased to 1700 *** optimal geometrical dimensions for achieving the maximum breakdown voltage BV GS and blocking voltage V block are also represented in the paper.

关键词： bipolar static induction transistor voltage-resistant capability punch-through deep trench

A computer simulation of nucleation and growth of thin films

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Science China(Physics,Mechanics & Astronomy) 2004年第4期47卷 442-451页

作者： ZHENG Xiaoping1,ZHANG Peifeng2,HE Deyan2,LIU Jun2& MA Jiantai3 1. Key Laboratory of Opto-Electronic Technology and Intelligent Control, Ministry of Education, lanzhou jiaotong university, lanzhou 730070, China 2. School of Physical Science and Technology, lanzhou university, lanzhou 730000, China 3. School of Chemistry and Chemistry Engineering, lanzhou university, lanzhou 730000, China Key Laboratory of Opto-Electronic Technology and Intelligent Control Ministry of Education Lanzhou Jiaotong University Lanzhou China School of Physical Science and Technology Lanzhou University Lanzhou China School of Chemistry and Chemistry Engineering Lanzhou University Lanzhou China

A three-dimensional kinetic Monte Carlo technique has been developed for simulating the nucleation and growth of thin films. This model involves incident atom attachment, surface diffusion of the atoms on the growing surface and atom detachment from the growing surface. It takes some new effects into account, such as a significant improvement in calculation of activation energy for the atom diffusion, which renders the model more reasonable. In addition three optimum temperatures and the consistency of their dependence on deposition rate have been found out; the dependence of the surface roughness and relative density on the deposition rate has been discussed; and the approximation of freezing neighbour atoms and periodic boundary conditions has been applied.

关键词： Monte Carlo, thin film, nucleation, surface roughness, relative density.

Guided wave propagation in multilayered piezoelectric structures

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Science China(Physics,Mechanics & Astronomy) 2009年第7期52卷 1094-1104页

作者： GUO YongQiang1, CHEN WeiQiu2,3 & ZHANG YongLiang4 1 Key Laboratory of Mechanics on Disaster and Environment in Western China, Ministry of Education, and School of Civil Engineering and Mechanics, lanzhou university, lanzhou 730000, China 2 Key Laboratory of Soft Soils and Geoenvironmental Engineering, Ministry of Education, and Department of Civil Engineering, Zhejiang university, Hangzhou 310058, China 3 Department of Engineering Mechanics, Zhejiang university, Hangzhou 310027, China 4 School of Civil Engineering, lanzhou jiaotong university, lanzhou 730070, China Key Laboratory of Mechanics on Disaster and Environment in Western China Ministry of Education and School of Civil Engineering and Mechanics Lanzhou University Lanzhou China Key Laboratory of Soft Soils and Geoenvironmental Engineering Ministry of Education and Department of Civil Engineering Zhejiang University Hangzhou China Department of Engineering Mechanics Zhejiang University Hangzhou China School of Civil Engineering Lanzhou Jiaotong University Lanzhou China

A general formulation of the method of the reverberation-ray matrix (MRRM) based on the state space formalism and plane wave expansion technique is presented for the analysis of guided waves in multilayered piezoelectric structures. Each layer of the structure is made of an arbitrarily anisotropic piezoelectric material. Since the state equation of each layer is derived from the three-dimensional theory of linear piezoelectricity, all wave modes are included in the formulation. Within the framework of the MRRM, the phase relation is properly established by excluding exponentially growing functions, while the scattering relation is also appropriately set up by avoiding matrix inversion operation. Consequently, the present MRRM is unconditionally numerically stable and free from computational limitations to the total number of layers, the thickness of individual layers, and the frequency range. Numerical examples are given to illustrate the good performance of the proposed formulation for the analysis of the dispersion characteristic of waves in layered piezoelectric structures.

关键词： multilayered piezoelectric structures the method of reverberation-ray matrix guided waves dispersion characteristic

Improvements on radiation-hardened performance of static induction transistor

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Science China(Information Sciences) 2010年第5期53卷 1089-1096页

作者： WANG YongShun 1 , LUO XianLiang 1 , LI HaiRong 2 , WANG ZiTing 1 , WU Rong 1 , ZHANG CaiZhen 2 & LI SiYuan 2 1 School of Electronic and Information Engineering, lanzhou jiaotong university, lanzhou 730070, China 2 Institute of Microelectronics, School of Physical Science and Technology, lanzhou university, lanzhou 730000, China School of Electronic and Information Engineering Lanzhou Jiaotong University Lanzhou China Institute of Microelectronics School of Physical Science and Technology Lanzhou University Lanzhou China

The radiation-hardened performances of static induction transistor (SIT) have been studied in depth in this paper. The effects of radiation of electron beam on the I-V characteristics, carrier distribution and potential distribution in the channel of SIT have been represented. A large number of electron-hole pairs are generated in the depletion region of reversely biased gate-channel PN junction. The radiation-generated electrons drift towards the drain region at high positive potential, while generated holes flow into gate region biased to the lowest potential. With the accumulation of holes in gate region, the gate potential is boosted, resulting in a decrease in the height of potential barrier in channel, and an increase in drain current. I-V characteristics of SIT in the presence of radiation have been theoretically derived, and compared with experimental results. With the increase in thickness of epitaxial layer, the radiation-hardened capability of SIT is continuously improved until the optimum thickness of 26 μm is reached. The optimum matching relationship among geometric, material and technological parameters has been represented to acquire excellent radiation-hardened performances of SIT.

关键词： static induction transistor radiation-resistant potential barrier electron beam radiationgenerated carriers

TRAVELLING FRONT SOLUTIONS IN A DIFFUSIVE VECTOR DISEASE MODEL WITH SPATIO-TEMPORAL DELAY

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Annals of Differential Equations 2012年第4期28卷 471-479页

作者： Cunhua Zhang Dept.of Math.,lanzhou jiaotong university,lanzhou 730070

This paper is concerned with travelling front solutions to a vector disease model with a spatio-temporal delay incorporated as an integral convolution over all the past time up to now and the whole one-dimensional spatial domain *** the delay kernel is assumed to be the strong generic kernel,using the linear chain techniques and the geometric singular perturbation theory,the existence of travelling front solutions is shown for small delay.

关键词： diffusive vector disease model nonlocal delay strong generic kernel travelling wave fronts

Multifield coupling model and its applications for pile foundation in permafrost

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Science China Earth Sciences 2005年第7期48卷 968-977页

作者： WU Yaping1,2, ZHU Yuanlin2, GUO Chunxiang1, SU Qiang1 & MA Wei2 1. School of Civil Engineering, lanzhou jiaotong university, lanzhou 730070, China 2. State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, lanzhou 730000, China School of Civil Engineering Lanzhou Jiaotong University Lanzhou 730070 China State Key Laboratory of Frozen Soil Engineering Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China

Importing the interface element which links the frozen soil base with concrete piles and considering the couplings of stress field, temperature field and moisture field, this paper es- tablishes the nonlinear visco-elastic plastic finite element model of pile-soil. For a practical bridge structure the stress field and displacement field of single pile in freezing process are calculated. This paper emphatically studies the process of the tangential frost heave stress field, freezing stress field and displacement field varying with time, and ulteriorly studies time variation process of single pile carrying capacity in freezing process.

关键词： permafrost pile foundation freezing process multifield coupling analysis model.

OPTIMAL CONTROL PROBLEM FOR A PERIODIC PREDATOR-PREY MODEL WITH AGE-DEPENDENCE

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Annals of Differential Equations 2012年第3期28卷 313-319页

作者： Zhixue Luo ,Zhenggang Ba,Xiaodi Yu(Dept.of Math.,lanzhou jiaotong university,lanzhou 730070)

In this paper,we investigate optimal policy for periodic predator-prey system with ***,we consider the model with periodic vital rates and initial *** existence of optimal control strategy is discussed by Mazur’s the... 详细信息

关键词： periodic predator-prey age-dependence optimal harvesting control the maximum principle