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Diffusion Equation on Fractals:Three-Dimensional Case

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Communications in Nonlinear Science and Numerical Simulation 1999年第3期4卷 3-5页

作者： Qiuhua ZENG and Houqiang LI(department of Physics, sichuan University,{2., china) department of Physics Sichuan University ChengDu 610064 China

IntroductionInrecentyearsthephenomenonofunusualtrajnsport-prop***onindisorderedmediaorfractalmedia,anomalousdiffusionistheoretic... 详细信息

IntroductionInrecentyearsthephenomenonofunusualtrajnsport-prop***onindisorderedmediaorfractalmedia,anomalousdiffusionistheoretic...

关键词： comb model probability density diffusion on fractals

Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

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Wuhan University Journal of Natural Sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2. 3 ,HUANG Zhiqin 2. 3, 4 1. The Faculty of Geography and Resources Science, sichuan Normal University, chengdu 610066, sichuan, china 2. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, chengdu 610041, sichuan, china 3. Graduate University of the Chinese Academy of Sciences, Beijing 100049, china 4. Information Center of Land and Resources department of sichuan Province, chengdu 610041, sichuan, china The Faculty of Geography Resources Science Sichuan Normal University 610066 Chengdu Sichuan China Institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate University of the Chinese Academy of Sciences 100049 Beijing China Information Center of Land Resources department of sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992.is extracted from the dynamic polygons of 2.02. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 35°. The areas of steep land cultivated had been slowly reduced from 1992.to 2.02. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area

Numerical simulation of air-water two-phase flow over stepped spillways

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Science china(Technological Sciences) 2006年第6期49卷 674-684页

作者： CHENG Xiangju1, CHEN Yongcan1 & LUO Lin2.1. department of Hydraulic Engineering, Tsinghua University, Beijing 100084, china 2. State Key Laboratory of Hydraulics and Mountain River Engineering, {2. University, chengdu 610065, china department of Hydraulic Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Hydraulics Mountain River Engineering Sichuan University Chengdu 610065 China

Stepped spillways for significant energy dissipation along the chute have gained interest; popularity among researchers; dam engineers. Due to the complexity of air-water two-phase flow over stepped spillways, the finite volume computational fluid dynamics module of the FLUENT software was used to simulate the main characteristics of the flow. Adopting the RNG k- turbulence model, the mixture flow model for air-water two-phase flow was used to simulate the flow field over stepped spillway with the PISO arithmetic technique. The numerical result successfully reproduced the complex flow over a stepped spillway of an experiment case, including the interaction between entrained air bubbles; cavity recirculation in the skimming flow regime, velocity distribution; the pressure profiles on the step surface as well. The result is helpful for understanding the detailed information about energy dissipation over stepped spillways.

关键词： stepped spillway, mixture model, RNG k-εmodel, air-water two-phase flow.

Anomalous Fractional Diffusion Equation forTransport Phenomena

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 99-104页

作者： Qiuhua ZENG Houqiang LI De LIU(department of Physics, sichuan University,{2., china) department of Physics Sichuan University ChengDu 610064 China

We derive the standard diffusion equation from the continuity equationand by discussing the defectiveness of earlier proposed equations, we get the generalizedfractional diffusion equation for anomalous diffusion.

关键词： fractal lattice probability density fractal anomalous diffusion

Representation of Integers by Ternary Quadratic Forms

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Acta Mathematica Sinica,English Series 2001年第4期17卷 715-720页

作者： De Lang LI Chun Lai ZHAO department of mathematics, {2. University, chengdu 610064, P. R. china department of mathematics, Peking University, Beijing 100871, P. R. china 四川大学数学系四川成都北京大学数学系北京

In this paper we give a formula for the number of representations of some square-free integers by certain ternary quadratic forms and estimate the lower bound of the 2.power appearing in this number.

关键词： Congruent elliptic curve Tate-Shafarevich group Modular form Class number

The Space of Maps from a Locally Compact Space to a Banach Space

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Acta Mathematica Sinica,English Series 1997年第3期13卷 333-336页

作者： Wang Yangeng (department of mathematics,{2. University,chengdu 610064,china) department of mathematics Sichuan University

The space of continuous maps from a topological space X to a topological space Y is denoted by C（X,Y）with the compact-open *** this paper we prove that C（X,Y）is an absolute retract if X is a locally compact separable metric space and Y a convex set in a Banach *** the above fact we know that C（X,Y）is homomorphic to Hilbert space l2./sub> if X is a locally compact separable metric space and Y a separable Banach space;in particular,C（Rn,Rm） is homomorphic to Hilbert space l2./sub>.

关键词： Absolute retract Function space Infinite-dimensional manifold

Theoretical study of aging effects on LaNi_(5) tritium storage

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 676-686页

作者： PING Feilin1,2. JIANG Gang1, ZHANG Lin2.& ZHU Zhenghe1 1. Institute of Atomic and Molecular Physics, sichuan University, chengdu 610065,{2. 2. Research Center of Laser Fusion, Mianyang 62.900,{2. 1. Institute of Atomic and Molecular Physics Sichuan University 610065 Chengdu China 2. Research Center of Laser Fusion 621900 Miangyang China

The electronic structure and energy of La2.i10H12.and La2.i10H11He (He is at tetrahedral, octahedral or twelve-face polyhedral interstitials) double cells have been calculated using the density functional theory. Their equilibrium structure, energy bands, electronic density of states (DOS) and X-ray diffraction are presented and discussed. The results indicate the helium-3 produced due to the decay of tritium is most possibly sited at twelve-face polyhedral and octahedral interstices and changes the thermodynamic properties of LaNi5 tritide system. The changes due to aging such as the reduction in the isotherm plateau pressure, increase of the isotherm plateau slope, and appearance of deeply trapped hydrogen are caused not only by the lattice expansion, but also by modification of the electronic structure due to the presence of He.

关键词： LaNi5 alloy, density functional theory, electronic structure, aging.

Enantioselective Reduction of Prochiral Ketones Catalyed by Oxazaborolidine Derived from L-Cystine

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Chinese Chemical Letters 1997年第8期8卷 679-680页

作者： Xing Shu Li Xiao Ling Zhang Ru Gang Xie(department of Chemistry, sichuan {2. University, chengdu, 610064)(department of Chemistry, sichuan Educational College, chengdu, 610041) department of Chemistry Sichuan Union University Chengdu 610064 China department of Chemistry Sichuan Educational College Chengdu 610041 China

Two new chiral oxazaborolidine derivated from L-cystine have been used to catalyze the enantioselective reduction of prochiral ketones and the secondary alcohols are obtained with good to excellent opitical yields.

关键词： Enantioselective Reduction of Prochiral Ketones Catalyed by Oxazaborolidine Derived from L-Cystine

A study of the optimal solution of a macroeconomics model

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西南师范大学学报(自然科学版) 1999年第5期24卷 519-525页

作者： Xiong Dasheng 1,Du Dongyao 2.1 department of mathematics,Southwest{2. Normal University,Chongqing 400715 2.Financial Section,sichuan union University,chengdu 610065 西南师范大学数学系重庆四川大学financial section 重庆

The optimal economic growth is always a main problem in economic control theory and it has been investigated by many scholars in their papers. A new sufficient condition of optimal control from a new angle is put forw... 详细信息

关键词： optimal economic growth optimal control sufficient condition trajectory