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Upscaling conductivity and porosity in three-dimensional heterogeneous porous media

Chinese Science Bulletin 2004年第22期49卷 2415-2423页

作者： ZHANG Yong Hydrologic Science,University of California,Davis,CA 95616,usa Desert Research Institute,2215 Raggio Parkway,Reno,NV 89512,usa Hydrologic Science University of California Davis CA 95616 United States Desert Research Institute 2215 Raggio Parkway Reno NV 89512 United States

An empirical formula is presented to upscale the conductivity of 3-dimensional heterogeneous porous me- dia, in which the distribution of local-scale conductivity is non-Gaussian with a high variance. The upscaled conductiv- ity is determined as a function of the volumetric proportion, the spatial connectivity and the statistical geometric length of high-permeable inclusions, and the arithmetic mean of con- ductivities of all hydrofacies. A systematic comparison to other traditional upscaling methods indicates that this em- pirical formula provides a better estimation of the equivalent conductivity. In the second part of this study, numerical ex- periments of solute migration reveal that porosity also needs to be upscaled to capture the transport of contaminants in a heterogeneous medium using an effective or upscaled homo- geneous medium. This is due to the tendency of contaminants to be preferrentially transported by 3-dimensional pathways composed of high-permeable materials in heterogeneous aquifer systems. The apparent difference between the actual transport velocity of contaminants and the upscaled velocity, based on the equivalent conductivity, forces upscaling of po- rosity. Further systematic analyses demonstrate that the up- scaled porosity follows a non-linear trend as the content of high-permeable sediments decreases. Resultant upscaled porosity, with values varying between 0.004 and 1.5, is be- yond the definition of the traditional porosity on the representative elementary volume (REV) scale. When the content of high-permeable materials is less than 30%, the upscaling of porosity is critical in the simulation of the contaminant transport in a heterogeneous medium using an upscaled, homogeneous counterpart.

关键词：标度方法传导率多孔性三维空间异类多孔介质多孔材料

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Simulation of Seasonal Circulations and Thermohaline Variabilities in the Gulf of Thailand

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Advances in Atmospheric Sciences 2008年第3期25卷 489-506页

作者： Nitima ASCHARIYAPHOTHA Prungchan WONGWISES Somchai WONGWISES usa Wannasingha HUMPHRIES 游小宝 The Joint Graduate School of Energy and Environment King Mongkut's University of Technology Thonburi The Joint Graduate School of Energy and Environment King Mongkut's University of Technology ThonburiBangkok 10140Thailand Department of Mechanical Engineering King Mongkut's University of Technology ThonburkBangkok 10140Thailand Department of Mathematics King Mongkut's University of Technology ThonburiBangkok 10140Thailand Institute of Atmospheric Physics Chinese Academy of SciencesBeijing 100029

Based on the Princeton Ocean Model （POM）, the seasonal thermohaline feature and the ocean circulation in the Gulf of Thailand （GOT）, situated between 6°N to 14°N latitude and 99°E to 105°E longitude, were studied numerically with 37 × 97 orthogonal curvilinear grid and 10 vertical sigma levels conforming to a realistic bottom topography. A spin-up phase of the first model run was executed using wind stress calculated from climatological monthly mean wind, restoring-type surface heat and salt, and climatological monthly mean fresh water flux data. In this paper, the temperature and salinity fields taken from Levitus94 data sets and the calculated temperature and salinity from the model run for 12-month mean and for each season are presented where the winter, summer, rainy, and end of the rainy seasons of Thailand are represented by the months January, April, July, and October, respectively. The simulated circulations are also described. The results show that the temperature in the GoT is warmer than the temperature of the other parts connected to the South China Sea （SCS）. At any depth of inflow from SCS into the GoT, the salinity is high, but in the outflow from the GoT at the surface, the salinity is low. The strong circulations are clockwise during summer and the rainy seasons of Thailand, which are the East Asian monsoon periods, northeasterly and southwesterly during summer. They occur near Pattani and Narathiwat provinces during summer and in the central GoT during the rainy seasons. Sensitivity experiments were designed to investigate the effects of wind forcing and open boundary conditions. Wind forcing is shown to be the important factor for generating the circulation in the GoT. The lateral velocity at the open boundaries is of considerable importance to current circulation for the rainy and end of the rainy seasons, with insignificant effect for the winter and summer seasons of Thailand.

关键词： seasonal circulation Gulf of Thailand spin-up phase thermohaline curvilinear grid

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Discrete Calderón-type Reproducing Formula

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Acta Mathematica Sinica,English Series 2000年第2期16卷 277-294页

作者： Yongsheng Han Department of Mathematics,Auburn University,Auburn,Alabama 36849-5310,usa Department of Mathematics Auburn University Auburn Alabama 36849-5310 USA

In this paper we use the Calderón-Zygmund operator theory to provide a discrete Calderón- type reproducing *** translation,dilation and,in particular,the Fourier transform are never used in the proofs,all results still hold on spaces of homogeneous type introduced by Coifman and Weiss. As a consequence,we obtain a class of frames with the minimum regularity properties.

关键词： Spaces of homogeneous type Calderón reproducing formula Frame

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ADVANCED SYNTHESIS OF LIGHT METALS

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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 531-536页

作者： F.H. Froes(IMAP, University of Idaho, Moscow, ID 838443026, usa ) Univ of Idaho Moscow United States

The synthesis, processing and mechanical properties of the light metals, aluminum,magnesium and titanium Produced by advanced techniques are reviewed. Synthesis techniques to be addressed will include rapid solidifica... 详细信息

关键词： synthesis/processing powder metallurgy lightweight metals,aluminum magnesium,titanium rapid solidification spray depositin mechanical alloying Plasma processing,vapor deposition

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Boundary Layer Theory and the Zero-Viscosity Limit of the Navier-Stokes Equation

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Acta Mathematica Sinica,English Series 2000年第2期16卷 207-218页

作者： Weinan E Department of Mathematics and Program in Applied and Computational Mathematics,Princeton University,usa Department of Mathematics and Program in Applied and Computational Mathematics Princeton University Princeton USA

A central problem in the mathematical analysis of fluid dynamics is the asymptotic limit of the fluid flow as viscosity goes to *** is particularly important when boundaries are present since vorticitv is typically generated at the boundary as a result of boundary layer *** boundary laver theory,developed by Prandtl about a hundred years ago,has become a standard tool in addressing these *** at the mathematical level,there is still a lack of fundamental understanding of these questions and the validity of the boundary layer *** this article,we review recent progresses on the analysis of Prandtl’s equation and the related issue of the zero-viscosity limit for the solutions of the Navier-Stokes *** also discuss some directions where progress is expected in the near future.

关键词： Boundary layer Blow-up Zero-viscosity limit Prandtl’s equation

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The Symplectic Floer Homology of the Square Knot and Granny Knots

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Acta Mathematica Sinica,English Series 1999年第1期15卷 1-10页

作者： Weiping LiDepartment of Mathematics,Oklahoma State University,Stillwater,Oklahoma 74078-0613,usa Department of Mathematics Oklahoma State University Stillwater USA

Using a kind of Mayer-Vietoris principle for the symplectic Floer homology of knots,we compute the symplectic Floer homology of the square knot and granny knots.

关键词： Knot Knot Cobordism Maslov Index Floer Homology

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Polynomials,Higher Order Sobolev Extension Theorems and Interpolation Inequalities on Weighted Folland-Stein Spaces on Stratified Groups

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Acta Mathematica Sinica,English Series 2000年第3期16卷 405-444页

作者： Guozhen Lu Department of Mathematics,Wayne State University,Detroit,MI 48202,usa Department of Mathematics Wayne State University Detroit USA

This paper consists of three main *** of them is to develop local and global Sobolev interpolation inequalities of any higher order for the nonisotropic Sobolev spaces on stratified nilpotent Lie *** the extensive research after Jerison’s work[3]on Poincaré-type inequalities for Hrmander’s vector fields over the years,our results given here even in the nonweighted case appear to be *** interpolation inequalities have crucial applications to subelliptic or parabolic PDE’s involving vector *** main tools to prove such inequalities are approximating the Sobolev func- tions by polynomials associated with the left invariant vector fields on *** very useful properties for polynomials associated with the functions are given here and they appear to have independent interests in their own *** the existence of such polynomials is the second main part of this *** results of these two parts have been announced in the author’s paper in Mathematical Research Letters[38]. The third main part of this paper contains extension theorems on anisotropic Sobolev spaces on stratified groups and their applications to proving Sobolev interpolation inequalities on(εδ)domains. Some results of weighted Sobolev spaces are also given *** construct a linear extension operator which is bounded on different Sobolev spaces *** particular,we are able to construct a bounded linear extension operator such that the derivatives of the extended function can be controlled by the same order of derivatives of the given Sobolev *** are stated and proved for weighted anisotropic Sobolev spaces on stratified groups.

关键词： Poincaré inequalities Extension theorems Interpolation inequalities Anisotropic Sobolev spaces A_p weights (ε,δ)domains Vector fields Polynomials on stratified groups

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HIGH-ORDER WENO SIMULATIONS OF THREE-DIMENSIONAL RESHOCKED RICHTMYER-MESHKOV INSTABILITY TO LATE TIMES:DYNAMICS,DEPENDENCE ON INITIAL CONDITIONS,AND COMPARISONS TO EXPERIMENTAL DATA

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Acta Mathematica Scientia 2010年第2期30卷 595-620页

作者： Oleg Schilling Marco Latini Lawrence Livermore National Laboratory Applied and Computational Mathematics California Institute of Technology CNA Corporation

The dynamics of the reshocked multi-mode Richtmyer-Meshkov instability is investigated using 513 × 257^2 three-dimensional ninth-order weighted essentially nonoscil- latory shock-capturing simulations. A two-mode initial perturbation with superposed ran- dom noise is used to model the Mach 1.5 air/SF6 Vetter-Sturtevant shock tube experiment. The mass fraction and enstrophy isosurfaces, and density cross-sections are utilized to show the detailed flow structure before, during, and after reshock. It is shown that the mixing layer growth agrees well with the experimentally measured growth rate before and after reshock. The post-reshock growth rate is also in good agreement with the prediction of the Mikaelian model. A parametric study of the sensitivity of the layer growth to the choice of amplitudes of the short and long wavelength initial interfacial perturbation is also pre- sented. Finally, the amplification effects of reshock are quantified using the evolution of the turbulent kinetic energy and turbulent enstrophy spectra, as well as the evolution of the baroclinic enstrophy production, buoyancy production, and shear production terms in the enstrophy and turbulent kinetic transport equations.

关键词： Richtmyer-Meshkov instability reshock mixing properties weighted essen-tially nonoscillatory (WENO) method

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Targeted cancer therapies based on antibodies directed against epidermal growth factor receptor:status and perspectives

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Acta Pharmacologica Sinica 2007年第9期28卷 1476-1493页

作者： Zhenping ZHU Im Clone Systems Incorporated,New York,NY 10014,usa ImClone Systems Incorporated New York USA

Compelling experimental and clinical evidence suggests that epidermal growthfactor receptor (EGFR) plays an important role in the pathogenesis of a variety ofhuman cancers;thus,providing a strong rationale for the development of receptorantagonists as effective and specific therapeutic strategies for the treatment ofEGFR-expressing *** antibodies (mAb),owing to their highspecificity towards a given target,represent a unique class of novel cancertherapeutics.A number of anti-EGFR mAb are currently being developed in ourclinic,including two that have been approved by the United States Food andDrug Administration for the treatment of refractory metastatic colorectal cancer(mCRC) and squamous cell carcinomas of the head and neck (SCCHN).Cetuximab(Erbitux,IMC-C225),an IgG1 mAb,has demonstrated significant antitumor activity,both as a single agent and in combination with chemotherapeutics and radiation,in patients with refractory mCRC and SCCHN,***(Vectibix),an IgG2 mAb,has been approved as a single agent for the treatment ofpatients with refractory *** mAb,via blocking ligand/receptorinteractions,exert their biological activity via multiple mechanisms,includinginhibition of cell cycle progression,potentiation of cell apoptosis,inhibition ofDNA repair,inhibition of angiogenesis,tumor cell invasion and metastasis and,potentially,induction of immunological effector ***-EGFR anti-bodies have demonstrated good safety profiles and potent anticancer activity inour clinic and may prove to be efficacious agents in the treatment of a variety ofhuman malignancies.

关键词： wear particles osteolysis aseptic loosening doxycycline

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Energetics and Propagation of Coronal Mass Ejections in Different Plasma Environments

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Chinese Journal of Astronomy and Astrophysics 2002年第6期2卷 539-556页

作者： Jun LinHarvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, usa Harvard-Smithsonian Center for Astrophysics 60 Garden Street Cambridge MA 02138 USA

Based on previous work, we investigate the propagation of CMEs in a more realistic plasma environment than the isothermal atmosphere, and find that it is a slightly faster reconnection for flux ropes to break free. The average Alfven Mach number MA for the inflow into the reconnection site has to be at least 0.013 in order to give a plausible eruption (compared to MA = 0.005 for the isothermal atmosphere). Taking MA = 0.1, we find that the energy output and the electric field induced inside the current sheet match the temporal behavior inferred from the energetic, long duration, CME-associated X-ray events. The results indicate that catastrophic loss of equilibrium in the coronal magnetic field provides the most promising mechanism for major solar eruptions, and that the more energetic the eruption is, the earlier the associated flare peaks. The variation of the output power with the background field strength revealed by our calculations implies the poor correlation between slow CMEs and solar flares. This work also further confirms the explanation we proposed for the peculiar motion of giant X-ray arches and anomalous post-flare loops. Their kinematic pattern and observed heights are determined by the local Alfven speed and its variation with height.

关键词： Sun: CMEs - Sun: atmosphere - Sun: magnetic fields

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