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Remarks on Vanishing Viscosity Limits for the 3D Navier-Stokes Equations with a Slip Boundary Condition

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Chinese Annals of Mathematics,Series B 2011年第3期32卷 321-332页

作者： Yuelong XIAO1 Zhouping XIN2.1institute for Computational and applied Mathematics,Xiangtan {2.,Xiangtan 411105,Hunan,china The institute of Mathematical Sciences,The Chinese {2. of Hong Kong,Hong Kong,china.2.he institute of Mathematical Sciences,The Chinese {2. of Hong Kong,Hong Kong,china. The institute of Mathematical Sciences The Chinese University of Hong Kong Hong Kong China

The authors study vanishing viscosity limits of solutions to the 3-dimensional incompressible Navier-Stokes system in general smooth domains with curved boundaries for a class of slip boundary conditions. In contrast to the case of flat boundaries, where the uniform convergence in super-norm can be obtained, the asymptotic behavior of viscous solutions for small viscosity depends on the curvature of the boundary in general. It is shown, in particular, that the viscous solution converges to that of the ideal Euler equations in C（[0, T]; HI（Ω）） provided that the initial vorticity vanishes on the boundary of the domain.

关键词： Poincare inequality Sobolev spaces with variable exponent

Theoretical study on S_1(~1B_(3u)) state electronic structure and absorption spectrum of pyrazine

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Science china chemistry 2008年第12期51卷 1166-1173页

作者： HE RongXing1, ZHU ChaoYuan 2. CHIN Chih-Hao3 & LIN Sheng-Hsien2.3 1 College of chemistry and Chemical Engineering, Southwest university, Chongqing 400715,{2. 2.Department of applied chemistry, institute of Molecular Science and Center for Interdisciplinary Molecular Science, National Chiao-Tung university, Hsinchu 300,{2. 3 institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 106,{2. 1. College of chemistry and Chemical Engineering Southwest University Chongqing 400715 China 2. Department of applied chemistry Institute of Molecular Science and Center for Interdisciplinary Molecular Science National Chiao-Tung University Hsinchu 300 China 3. institute of Atomic and Molecular Sciences Academia Sinica Taipei 106 China

Making use of a set of quantum chemistry methods, the harmonic potential surfaces of the ground state (S0(1Ag)) and the first (S1(1B3u)) excited state of pyrazine are investigated, and the electronic structures of the two states are characterized. In the present study, the conventional quantum mechanical method, taking account of the Born-Oppenheimer adiabatic approximation, is adopted to simulate the absorp-tion spectrum of S1(1B3u) state of pyrazine. The assignment of main vibronic transitions is made for S1(1B3u) state. It is found that the spectral profile is mainly described by the Franck-Condon progression of totally symmetric mode ν6a. For the five totally symmetric modes, the present calculations show that the frequency differences between the ground and the S1(1B3u) state are small. Therefore the displaced harmonic oscillator approximation along with Franck-Condon transition is used to simulate S1(1B3u) absorption spectra. The distortion effect due to the so-called quadratic coupling is demonstrated to be unimportant for the absorption spectrum, except the coupling mode ν10a. The calculated S1(1B3u) ab-sorption spectrum is in reasonable agreement with the experimental spectra.

关键词： pyrazine absorption spectrum quantum mechanical method electronic structure

Biological aspects on the cultures of the entomophthoralean fungus Pandora delphacis grown on broomcorn millets

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Science Bulletin 2003年第17期48卷 1816-1821页

作者： FENG Mingguang1,2.& LIANG Yong1 1. institute of Microbiology, College of Life Sciences, Zhejiang Univer-sity, Hangzhou 31002., china 2. institute of applied Entomology, College of Agricultural Sciences and Biotechnology, Zhejiang university, Hangzhou 31002., china institute of Microbiology College of Life Sciences Zhejiang University Hangzhou 310029 China

A novel method was developed to use glutinous broomcorn millets (Panicum miliaceum L.) as solid substrate to make cultures of the entomophthoralean fungus Pandora delphacis specifically pathogenic to planthoppers, leafhop-pers and aphids. Steamed millets with water content of 45% were inoculated with a liquid culture of P. delphacis at a ratio of 2.% (v/w) and then incubated at 2.℃ and L:D 12.12. The millets cultured for 3—17 d exhibited high potential for co-nidial production. The 5-d-old millet culture sporulated most abundantly, discharging up to 17.12.(1.31) 104 conidia/ millet. The cultures incubated for 7—11 d also had a satis-factory sporulation capability, yielding 13.00—13.90 104 conidia/millet. Compared to 2.32.(0.34) 104 conidia dis-charged from each of Myzus persicae adults killed by P. del-phacis and a ≤60-h duration of sporulation, each of the millets cultured for 5—11 d produced 5.6—7.4 times more conidia with an over doubled duration for conidial discharge (144 h). Among 106 M. persicae adults exposed to the shower of conidia discharged from the cultured millets, a total mor-tality of 69.8% caused by P. delphacis infection was observed within 7 d after exposure, but no death was attributed to the fungal infection in the aphids unexposed. The results indi-cate that the millet cultures of P. delphacis are biologically similar to aphid cadavers killed by the same fungus. Due to the superiority of the cultured millets to the cadavers in sporulation potential and duration, the method for making cultures of P. delphacis on the broomcorn millets is highly recommended for use in study of entomophthoralean fungi for microbial control. This is the first report on the success of the solid culture of Pandora species on cereals.

关键词： entomophthorales Pandora delphacis broomcorn millets solid culture sporulation capability aphid infectivity.

A new DNA algorithm to solve graph coloring problem

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Progress in Natural Science:Materials International 2007年第6期17卷 733-738页

作者： Jiang Xingpeng1, Li Yin2. Meng Ya3 and Meng Dazhi2.1. National Laboratory of Pattern Recognition,institute of Automation, Chinese Academy of Sciences, Beijing 100080, china 2. College of {2. Sciences, Beijing university of Technology, Beijing 10002., china 3. School of Science, Beijing institute of Technology, Beijing 100081, china) National Laboratory of Pattern Recognition Institute of Automation Chinese Academy of Sciences Beijing 100080 China College of applied Sciences Beijing University of Technology Beijing 100022 China School of Science Beijing Institute of Technology Beijing 100081 China

Using a small quantity of DNA molecules and little experimental time to solve complex problems successfully is a goal of DNA computing. Some NP-hard problems have been solved by DNA computing with lower time complexity than conventional computing. However, this advantage often brings higher space complexity and needs a large number of DNA encoding molecules. One example is graph coloring problem. Current DNA algorithms need exponentially increasing DNA encoding strands with the growing of problem size. Here we propose a new DNA algorithm of graph coloring problem based on the proof of four-color theorem. This algorithm has good properties of needing a relatively small number of operations in polynomial time and needing a small number of DNA encoding molecules (we need only 6R DNA encoding molecules if the number of regions in a graph is R).

关键词： DNA computing NP-hard problem graph coloring problem.

Daily variation of carbon flux in soils of Populus euphratica forests in the middle and lower reaches of the Tarim River

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Progress in Natural Science:Materials International 2007年第5期17卷 584-590页

作者： Huang Xiang , Chen Yaning , Li Weihong , Ma Jianxin and Chen Yapeng (xinjiang institute of Ecology and Geography, Chinese Academy of Sciences, {2. 830011, china Graduate university, Chinese Academy of Sciences, Beijing 100039, china) [a]xinjiang institute of Ecology and Geography Chinese Academy of Sciences Urumqi China [b]Chinese Academy of Sciences Graduate University Beijing China

In order to lucubrate the daily variation of respiration in soils of Populus euphratica forests and analyze its relationship with environmental factors in the middle and lower reaches of the Tarim River, the LI-8100 instrument of soil CO2.flux system was used to measure the parameters of soil carbon flux and air temperature 10 cm above ground surface along the profiles of Usyman, Archy River, Yengisu and Karday, and the relationships between the soil carbon flux and the soil moisture content were analyzed. The nonlinear regression analysis was carried out with the software SPSS13.0. We observed that: (1) soil respiration began to be restrained when the air temperature was up to 30℃10 cm above the ground surface; (2. the rates of soil respiration under the forests of Populus euphratica were significantly different at various moisture contents, the soil carbon flux was high along the Usyman profile, which has a high soil moisture content, and it was low along the profiles of Archy River, Yengisu and Karday, which has a low soil moisture content; (3) the exponential model can be used to explain the relationship between soil respiration and air temperature 10 cm above the ground surface. The average Q10 values along the profiles of Usyman, Archy River, Yengisu and Karday are 0. 61, 0.16, 0. 2. and 0. 35 respectively, much lower than the average of the world; (4) there is a positive correlation between the soil carbon flux and the soil moisture content.

关键词： Populus euphratica soil carbon flux air temperature 10 cm above ground surface soil moisture content the Tarim River.

Improvement of Lithium Interface Stability with 1,4-dioxane Pretreatment

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Journal of Wuhan university of Technology(Materials Science) 2007年第3期22卷 494-498页

作者：丁飞 Department of applied chemistry Harbin Institute of Technology

1,4-dioxane （DOA） was originally used to pretreat the lithium metal electrode in order to improve its interface stability. Electrochemical impedance spectra （EIS） measurements reveal that with DOA pretreatment, lithium electrode has a low and stable interfacial resistance during the storage in electrolyte for a long time. And it is also found that the pretreated lithium electrode has an improved interfacial performance in repeated charge/discharge cycles. Furthermore, it is proved by SEM that the pretreated one has smooth morphology after long-time storage or repeated charge/discharge cycles. Consequentially, because of more stable interface characteristics of lithium electrode, the rechargeable lithium cell with DOA pretreated lithium anode has an obviously enhanced discharging performance and a better cycleability, compared with that of the cell using the untreated lithium anode.

关键词： lithium battery interface film stability 1,4-dioxane pretreatment EIS

An Approximate Solution Technique Depending on an Artificial Parameter: A Special Example

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Communications in Nonlinear Science and Numerical Simulation 1998年第2期3卷 40-45页

作者： Jihuan HE (Shanghai university, Shanghai institute of {2. Mathematics and Mechanics, Shanghai 2.0072. china) Shanghai university Shanghai Institute of Applied Mathematics and Mechanics Shanghai 200072 China

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关键词： perturbation methods homotopy Duffing equation nonlinearity

An interpolating boundary element-free method (IBEFM) for elasticity problems

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Science china(Physics,Mechanics & Astronomy) 2010年第4期53卷 758-766页

作者： REN HongPing 1 , CHENG YuMin 2.& ZHANG Wu 1 1 School of Computer Engineering and Science, Shanghai university, Shanghai 2.0072. china 2.Shanghai {2. of applied Mathematics and Mechanics, Shanghai university, Shanghai 2.0072. china 1. School of Computer Engineering and Science Shanghai University Shanghai 200072 China2. Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

The paper begins by discussing the interpolating moving least-squares (IMLS) method. Then the formulae of the IMLS method obtained by Lancaster are revised. On the basis of the boundary element-free method (BEFM), combining the boundary integral equation method with the IMLS method improved in this paper, the interpolating boundary element-free method (IBEFM) for two-dimensional elasticity problems is presented, and the corresponding formulae of the IBEFM for two-dimensional elasticity problems are obtained. In the IMLS method in this paper, the shape function satisfies the property of Kronecker δ function, and then in the IBEFM the boundary conditions can be applied directly and easily. The IBEFM is a direct meshless boundary integral equation method in which the basic unknown quantity is the real solution to the nodal variables. Thus it gives a greater computational precision. Numerical examples are presented to demonstrate the method.

关键词： moving least-squares (MLS) approximation interpolating moving least-squares (IMLS) method boundary integral equation meshless method boundary element-free method (BEFM) interpolating boundary element-free method (IBEFM) elasticity problem

A new calculation method for the number of radial slots of a Terfenol rod

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Science china(Technological Sciences) 2009年第2期52卷 336-338页

作者： HE XiPing1 & ZHANG Pin2.1 applied Acoustics institute, Shaanxi Normal {2., Xi’an 710062. china 2.School of Science, Xi’an {2. of Architecture and Technology, Xi’an 710055, china 1. applied Acoustics institute Shaanxi Normal University Xi’an 710062 China 2. School of Science Xi’an University of Architecture and Technology Xi’an 710055 China

Terfenol is an ideal choice for medium to high power low frequency sonar. It can offer the transducer designer higher strain, higher power density, but the designer must be aware of the eddy current. To enhance efficiency of the barrel-stave transducer powered by a Terfenol rod, radial slots rather than laminations were used to control eddy currents in the Terfenol drive rod, and the effectiveness and the number of these slots were studied experimentally and calculated by finite element modeling. Based on the characteristic of vortex path, a new simple geometrical method to calculate the number of the radial slots of a Terfenol rod at the operating frequency is put forward in this paper. Moreover, the calculated results are in good agreement with those of using the finite element method (FEM) for the slotted Terfenol rod given by the literature. The method will save much cost to design Terfenol rod transducers.

关键词： Terfenol-D rod eddy current losses limit operating frequency