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Two-Level Stabilized Finite Volume Methods for the Stationary Navier-Stokes Equations

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Advances in Applied Mathematics and Mechanics 2013年第1期5卷 19-35页

作者： Tong Zhang Shunwei Xu School of Mathematics&Information Science Henan Polytechnic UniversityJiaozuo 454003HenanChina

In this work,two-level stabilized finite volume formulations for the 2D steady Navier-Stokes equations are *** methods are based on the local Gauss integration technique and the lowest equal-order finite element ***,the two-level stabilized finite volume methods involve solving one small NavierStokes problem on a coarse mesh with mesh size H,a large general Stokes problem for the Simple and Oseen two-level stabilized finite volume methods on the fine mesh with mesh size h=O(H^(2))or a large general Stokes equations for the Newton two-level stabilized finite volume method on a fine mesh with mesh size h=O(|logh|^(1/2)H^(3)).These methods we studied provide an approximate solution(ue v h,pe v h)with the convergence rate of same order as the standard stabilized finite volume method,which involve solving one large nonlinear problem on a fine mesh with mesh size ***,our methods can save a large amount of computational time.

关键词： Stationary Navier-Stokes equations finite volume method two-level method error estimate

Analysis to driving forces of land use change in Lu’an mining area

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中国有色金属学会会刊：英文版 2011年第S3期21卷 727-732页

作者： LIU Chang-hua, MA Xiao-xiao School of Surveying and Land Information Engineering, henan polytechnic university, Jiaozuo 454003, China School of Surveying and Land Information Engineering Henan Polytechnic University Jiaozuo 454003 China

By selecting impact factors of driving force and formulating evaluation criteria of the impacts, the evaluation system of corresponding driving force impact of land use change was established. Taking Lu'an mining area as an example, the specific impact factors of coal mine were comprehensively evaluated and analyzed in order to carry out qualitative and quantitative analysis for the driving force of mining-land use change. The principal component analysis shows that the social and economic development in mining area from 2000 to 2007 demonstrates continuous accelerate trends, and the impacts of its overall driving force to land use change are increased gradually. The socio-economic factors have more impacts to mining-land use change than those of the natural resources. The main driving force of mining-land use change also include population, technological progress and policy.

关键词： mining area land use change driving force evaluation factor principal component analysis

High-order harmonic generation in sub-one-cycle regime

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Chinese Physics B 2012年第6期21卷 280-287页

作者：向阳钮月萍祁义红龚尚庆 School of Computer Science and Thechnology Henan Polytechnic University Department of Physics East China University of Science and Technology

We theoretically investigate the high-order harmonic generation from the hydrogen atom driven by the laser pulses with the durations less than the optical cycle. It is found that the switching term of the laser field may have an obvious influence on the cutoff, intensity or plateau structure of the high-order harmonic spectrum. Generally speaking, the switching term can shorten the cutoff of the high-order harmonic spectrum for a relatively longer pulse and extend the cutoff for a relatively shorter pulse.

关键词： high-order harmonic generation sub-one-cycle pulse switching term

REGULARITY OF WEAK SOLUTIONS TO MAGNETO-MICROPOLAR FLUID EQUATIONS

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Acta Mathematica Scientia 2010年第5期30卷 1469-1480页

作者：原保全 School of Mathematics and Informatics Henan Polytechnic University

In this article, we study the regularity of weak solutions and the blow-up criteria for smooth solutions to the magneto-micropolar fluid equations in R3. We obtain the classical blow-up criteria for smooth solutions （u,w, b）, i.e., u ∈ Lq（0, T; LP（R3） for 2/q＋3/P≤ 1with 3〈P≤∞,u∈C（[0,T）;L3（R3））or△u∈Lq（0,T,LP）for 3/2〈P≤∞ satisfying 2/q＋3/P≤ 2. Moreover, our results indicate that the regularity of weak solutions is dominated by the velocity u of the fluid. In the end-point case p = ∞, the blow-up criteriacan be extended to more general spaces △u E L1 （0, T; B0∞,∞（R3）.

关键词： magneto-micropolar fluid equations regularity criteria blow-up criteria

SHRIMP zircon U-Pb ages from coal beds across the Permian-Triassic boundary, eastern Yunnan, southwestern China

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Journal of Palaeogeography 2018年第2期7卷 117-129页

作者： Juan Wang Long-Yi Shao Hao Wang Baruch Spiro David Large State Key Laboratory of Coal Resources and Safety Mining College of Geoscience and Surveying Engineering China University of Mining and Technology (Beijing) School of Resources and Environment Henan Polytechnic University Department of Mineralogy The Natural History MuseumLondon Faculty of Engineering University of Nottingham

The first SHRIMP zircon U e Pb ages from coal beds close to the end-Permian mass extinction are reported from the Ccoal seam in the Yantang Mine in Laibin Town, Xuanwei County, eastern Yunnan *** were extracted from kaolinite claystone layers, defined as tonsteins(volcanic ash deposits), in the subseam Band Bof the coal seam *** U-Pb ages are 252.0 ± 2.3 Ma and 250.3 ± 2.1 Ma for the sub-seam Band B, respectively. Within analytical uncertainties, these U-Pb ages include the time period of the onset of the mass extinction at 251.941 ± 0.037 Ma, which was obtained from the marine Meishan section in Zhejiang Province, ~1600 km away from the Yantang Mine. These new ages represent not only the first and closest ages to the PTB mass extinction in terrestrial coal beds, but also ages from the nearest site to the Emeishan volcanoes investigated so far. Therefore these new data provide the most accurate stratigraphic horizon of terrestrial facies of the end-Permian extinction in South China. The Emeishan volcanoes were likely the source of volcanic ash in the coal seams at the Xuanwei County and broader areas in South China. Furthermore, the minerals and geochemistry characteristics of the Ccoal seam also implied the influences of contemporaneous volcanic activities.

关键词： PTB mass extinction C1 coal seam SHRIMP U-Pb isotope age Xuanwei County Yunnan Province

Regularity Condition of Solutions to the Quasi-geostrophic Equations in Besov Spaces with Negative Indices

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Acta Mathematicae Applicatae Sinica 2010年第3期26卷 381-386页

作者： Bao-quan Yuan School of Mathematics and Information Science Henan Polytechnic University Henan 454000 China

With a Hǒlder type inequality in Besov spaces, we show that every strong solution θ（t, x） on （0, T ） of the dissipative quasi-geostrophic equations can be continued beyond T provided that ⊥θ（t, x） ∈L 2γ/... 详细信息

关键词： Quasi-geostrophic equations regularity conditions Besov spaces

Annual integral changes of time serial NDVI in mining subsidence area

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中国有色金属学会会刊：英文版 2011年第S3期21卷 583-588页

作者： MA Chao1, GUO Zeng-zhang1, ZHANG Xiao-ke2, HAN Rui-mei1 1. Key Laboratory of Mine Spatial Information Technologies of State Bureau of Surveying & Mapping, henan polytechnic university, Jiaozuo 454000, China 2. School of Coal Mining Engineering, Taiyuan university of Technology, Taiyuan 030024, China

By means of MORTRAN4 model of FLASSH module, an atmospheric correction of the SPOT II/IV data of four-year period for eight experimental coal faces of Lu'an mine area was done. The mining-affected zones were obtained with probability integral method. The normalized difference vegetation index (NDVI) and its mean were obtained by band ratio calculation at the mining subsidence area. Using FOURIER4 model of the fast Fourier transform (FFT) of discrete Fourier analysis theory, the mean NDVI time series data set was reconstructed. With the mean of NDVI transformed into amplitude and the phonological information transformed into phase, the law of NDVI variation by monthly, quarterly, annual were obtained. The annual integral of the time series of NDVI Fourier function (ANDVI) was obtained. The results show that an experience formula of ANDVI variation accompanies with mining time; A fast estimation formula of NPP by means of a coefficient of mining disturbance such as γ.

关键词： Lu’an mine area annual integral of NDVI net primary productivity coefficient of mining disturbance

Symmetry Reduction and Exact Solutions of a Hyperbolic Monge-Ampère Equation

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Chinese Annals of Mathematics,Series B 2012年第2期33卷 309-316页

作者： Zhongzhou DONG Yong CHEN Dexing KONG Zenggui WANG School of Mathematics and Information Science Henan Polytechnic UniversityJiaozuo 454003HenanChina Shanghai Key Laboratory of Trustworthy Computing East China Normal UniversityShanghai 200062China Center of Mathematical Sciences Zhejiang UniversityHangzhou 310027China School of Mathematics Sciences Liaocheng UniversityLiaocheng 252059ShandongChina

By means of the classical symmetry method, a hyperbolic Monge-Ampere equa- tion is investigated. The symmetry group is studied and its corresponding group invariant solutions are constructed. Based on the associated vector of the obtained symmetry, the authors construct the group-invariant optimal system of the hyperbolic Monge-Ampere equation, from which two interesting classes of solutions to the hyperbolic Monge-Ampere equation are obtained successfully.

关键词： Symmetry reduction Monge-Ampere equation Exact solutions

Global axisymmetric classical solutions of full compressible magnetohydrodynamic equations with vacuum free boundary and large initial data

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Science China Mathematics 2022年第3期65卷 471-500页

作者： Kunquan Li Zilai Li Yaobin Ou School of Mathematics Renmin University of ChinaBeijing 100872China School of Mathematics and Information Science Henan Polytechnic UniversityJiaozuo 454QQ0China

In this paper,the global existence of the classical solution to the vacuum free boundary problem of full compressible magnetohydrodynamic equations with large initial data and axial symmetry is *** solutions to the system(1.6)–(1.8) are in the class of radius-dependent solutions,i.e.,independent of the axial variable and the angular *** particular,the expanding rate of the moving boundary is *** main difficulty of this problem lies in the strong coupling of the magnetic field,velocity,temperature and the degenerate density near the free *** overcome the obstacle by establishing the lower bound of the temperature by using different Lagrangian coordinates,and deriving the uniform-in-time upper and lower bounds of the Lagrangian deformation variable r;by weighted estimates,and also the uniform-in-time weighted estimates of the higher-order derivatives of solutions by delicate analysis.

关键词： compressible magnetohydrodynamic equations vacuum free boundary global axisymmetric classical solutions large initial data