STREAMLINE DIFFUSION F.E.M. FOR SOBOLEV EQUATIONS WITH CONVECTION DOMINATED TERM

In this paper,a streamline diffusion F.E.M. for linear Sobolev equations with convection dominated term is given.According to the range of space time F.E mesh parameter h ,two choices for artifical diffusion parameter δ are presented,and for the corresponding computation schemes the stability and error estimates in suitable norms are estabilished.

A Priori and A Posteriori Error Estimates of Streamline Diffusion Finite Element Method for Optimal Control Problem Governed by Convection Dominated Diffusion Equation

In this paper,we investigate a streamline diffusion finite element approxi- mation scheme for the constrained optimal control problem governed by linear con- vection dominated diffusion equations.We prove the existence and uniqueness of the discretized scheme.Then a priori and a posteriori error estimates are derived for the state,the co-state and the control.Three numerical examples are presented to illustrate our theoretical results.

Effects of water level fluctuation on sedimentary characteristics and reservoir architecture of a lake, river dominated delta

The hydrodynamic conditions present in a river delta's formation are a highly important factor in the variation between its sedimentary regulation and characteristics. In the case of the lacustrine basin river-dominated delta, water level fluctuations and fluviation, are both important controlling factors of the sedimentary characteristics and reservoir architecture. To discuss the effects of water level fluctuation on sediment characteristics and reservoir architecture of this delta, the Fangniugou section in the east of the Songliao Basin was selected for study. Based on an outcrop investigation of the lacustrine basin river-dominated delta, combining with an analysis of the major and trace chemical elements in the sediments to determine the relative water depth, through architecture bounding surfaces and lithofacies division, sedimentary microfacies recognition and architectural element research, this work illustrated the effects of water level fluctuation on the reservoir architecture and established sedimentary models for the lacustrine basin river-dominated delta under various water level conditions. The results show that there are 8 lithofacies in the Fangniugou section. The fan delta front, which is the main object of this study, develops four sedimentary microfacies that include the underwater distributary channel, river mouth bar, sheet sand and interdistributary bay. The effects of water level fluctuation on different orders geographic architecture elements are respectively reflected in the vertical combination of the composite sand bodies, the plane combination of the single sand bodies, the particle size changes in the vertical of hyperplasia in the single sand body, the coset and lamina. In the case of the sand body development of the petroliferous basin, varying water level conditions and research locations resulted in significant variation in the distribution and combination of the sand bodies in the lacustrine basin.

LARGE DEVIATIONS FOR SUMS OF INDEPENDENT RANDOM VARIABLES WITH DOMINATEDLY VARYING TAILS

In this paper the large deviation results for partial and random sums Sn-ESn=n∑i=1Xi-n∑i=1EXi,n≥1;S（t）-ES（t）=N（t）∑i=1Xi-E（N（t）∑i=1Xi）,t≥0 are proved, where {N（t）;t ≥ 0} is a counting process of non-negative integer-valued random variables, and {Xn; n ≥ 1} are a sequence of independent non-negative random variables independent of {N（t）; t ≥ 0}. These results extend and improve some known conclusions.

Perturbation Analysis for Stability of Convolution Dominated Infinite Matrices

Stability of infinite matrices has important applications to spline approximation, wavelets, Gabor time-frequency analysis, etc. In this paper, perturbation analysis for convolution dominated infinite matrices was studied by introducing an idea of lp-stability at infinity. For infinite matrices in the Gohberg-Baskakov-Sjostrand class, a practical criterion for the lp-stability at infinity of convolution dominated infinite matrices on Zd under perturbation of compact operators was given.

The First Vertebrate Assemblage Dominated by Fishes and Turtles of the Jehol Biota in Jilin Province, NE China

Objective The Early Cretaceous sediments are well-exposed in southern Jilin Province,and yield abundant invertebrate and plant fossils,including the typical EosestheriaEphemeropsis trisetalis-Lycoptera（E-E-L）assemblage of the Jehol Biota（Shao Tiequan et al.,2017）.However,vertebrate fossils,especially tetrapods,are extremely rare and there is no formal documents on these fossils.Recently,a new fossil site dominated by fishes and turtles has been discovered in the middle part of the

High Resolution Compact Finite Difference Schemes for Convection Dominated Problems

In this short article, the upwind and central compact finite difference schemes for spatial discretization of the first-order derivative are analyzed. Comparison of the schemes is provided and the best discretization scheme for convection dominated problems is suggested.

MIXED FINITE ELEMENT METHOD FOR THE CONVECTION-DOMINATED DIFFUSION PROBLEMS WITH SMALL PARAMETER ε

In this paper a mixed finite element method for the convection dominated diffusion problems with small parameter ε is presented,the effect of the parameter ε on the approximation error is considered and a sufficient condition for optimal error estimates is derived.The paper also shows that under some conditions,the standard finite element method only gives a bounded solution,however the mixed finite element method gives a convergent one. Received March 1,1997. 1991 MR Subject Classification: 65N30,65M15.

A Passion For an Unusual Art:A female artist is committed to mastering the male-dominated art of high-pole lion dance

Lion dance is a popular folk activity in China,and is traditionally associated with joyful celebrations since it is thought to bring riches and good fortune.Dancers in lion costumes jump back and forth while integrating Chinese martial arts and acrobatics to the sounds of drums,cymbals,and resounding gongs.Such performances draw huge crowds,which always adds to a joyous mood.Lion dancer Liang Jiali,28,from Foshan City in south China’s Guangdong Province,carries the ancient tradition on poles of various heights.She was chosen at the age of seven to join the only elite women’s team in China,the Shunde Women’s Lion Dance Troupe.She has been attached to the male-dominated art genre for 21 years now.

Who will Dominate 2008 Fabrics China?

2008 Fabrics China Creation Competition, oriented with the theme of promoting product innovation, turns out to be one of the most influential and authoritative

Molecular detection of microbial communities associated with Microcystis vs Synechococcus dominated waters in Tianjin,China

Harmful cyanobacterial blooms cause many ecological disasters worldwide. During the development of cyanobacterial blooms, the diversity and domination of cyanobacterial taxa are of a particular concern. In this study, the microbial community structure within a water system, such as in Yuqiao Reservoir and Haihe River in Tianjin City, China, was compared by using next-generation sequencing. A total of 5 001 operational taxonomic units were obtained and clustered from filtered 16 S rDNA V3–V4 region sequences. The cyanobacterial and microbial structures greatly differed in these two water areas. Microcystis was dominant in Yuqiao, whereas Synechococcus was dominant in Haihe. Proteobacteria species were dominant among all detected samples. The relative abundances of Bacteroidetes and Planctomycetes were higher in Yuqiao Reservoir than in Haihe River, whereas Firmicutes and Verrucomicrobia were relatively abundant in Haihe River. Further analyses indicated that the domination of both cyanobacteria was strongly related to several environmental factors, such as total nitrogen, total phosphorus, and dissolved oxygen, reflecting the role of trophic states in shaping the dominance of cyanobacterial taxa. The present study provided the example for Microcystis and Synechococcus dominance along a cyanobacterial bloom in north China. Applying highthroughput sequencing could offer a wide field of vision in analyzing microbial community structures.

Planet wind: Planetary evolution dominated by electromagnetic forces

1. Introduction Over the five centuries since Copernicus, the focus of planetary science has transitioned from the visible realm to the invisible. In the more than 60 years following the advent of the space age, our ability to comprehend planets has grown from the gravitational forces to electromagnetic forces.

Generic Modeling and Control Framework for Power Systems Dominated by Power Converters Connected Through a Passive Transmission and Distribution Grid

In this paper,a compact mathematical model having an elegant structure,together with a generic control framework,are proposed for generic power systems dominated by power converters that are interconnected through a passive transmission and distribution(T&D)grid,by adopting the port-Hamiltonian(pH)systems theory and the fundamental circuit theory.The models of generic T&D lines are developed and then the model of a generic T&D grid is established.With the proposed control framework,the controlled converters are proven to be passive and Input-to-State Stable(ISS).The compact mathematical model is scalable and can be applied to power systems with multiple power electronic converters with generic passive controllers,passive local loads,and different types of passive T&D lines connected in a meshed configuration without self-loops,so it is very generic.Moreover,the resulting power system is proven to be ISS as well.The analysis is carried out without assumptions on constant frequency/voltage,constant loads,and/or lossless networks,except the need of passivity for all parts involved,and without using the Clarke/Park transformations or the graph theory.To simplify the presentation,three-phase balanced systems are adopted but the results can be easily adapted for single-phase or unbalanced three-phase systems.

Large deviations for heavy-tailed random sums of independent random variables with dominatedly varying tails

We prove large deviation results on the partial and random sums s n =Σ i=1 n X i , n?1; S(t)=Σ i=1 N(t) X i , t?0, where {N(t);t?0} are non-negative integer-valued random variables and {X n ;n?1} are independent non-negative random variables with distribution, F n , of X n , independent of {N(t);t?0}. Special attention is paid to the distribution of dominated variation.

Characterization and modeling of wind-dominated ambient noise in South China Sea

The action of wind on the sea surface plays an important role in the noise generation mechanism.Sea surface wind speed can be estimated accurately provided there is an accurate understanding of the relationship between the ocean ambient noise and wind speed.Many measurements and analyses of the wind dependence of ambient noise have been conducted.The approximate empirical rule given by Wenz[1]states that in the frequency band between 0.5and 5 kHz,the ambient sea-noise spectrum levels decrease

VARIATIONAL DISCRETIZATION FOR OPTIMAL CONTROL GOVERNED BY CONVECTION DOMINATED DIFFUSION EQUATIONS

In this paper, we study variational discretization for the constrained optimal control problem governed by convection dominated diffusion equations, where the state equation is approximated by the edge stabilization Galerkin method. A priori error estimates are derived for the state, the adjoint state and the control. Moreover, residual type a posteriori error estimates in the L^2-norm are obtained. Finally, two numerical experiments are presented to illustrate the theoretical results.

Phosphorus removal in small constructed wetlands dominated by submersed aquatic vegetation in South Florida, USA

Aims Free-surface flow-constructed wetland is a powerful means for the reduction of contaminants from agricultural runoff.Wetlands dominated by submerged aquatic vegetations(SAVs)may take up nutrients,particularly phosphorus(P),from surface flow with high efficiency.The objective of this study was to assess P removal performance by the SAV community under high and low P concentrations.Methods Weekly or biweekly inflow and outflow water samples were collected from four small constructed wetlands(test cells)planted with SAV in South Florida,USA,between September 1999 and September 2001.These test cells were divided into two groups,with the north test cells receiving a higher inflow total phosphorus(TP)concentration(average=75 lg l^(-1))than the south test cells receiving a lower TP concentration(average=23 lg l^(-1)).Limerock(LR)berms were installed in two of these test cells to allow an evaluation of the efficiency of this physical barrier to enhance wetland performance.Important findings North test cells displayed high TP removal of;60%while the removal efficiency of the south test cells was only;20%.Soluble reactive phosphorus concentrations in both north and south test cells were sequestered down to near-detection limit.High removal efficiencies for particulate phosphorus were also observed in the north test cells.The LR berms at the two test cells were found to be associated with decreases of an average TP removal of 2 lg l^(-1).Outflow TP concentration did not increase with inflow TP concentration,but increased with nominal hydraulic loading rates.Findings from this study demonstrated high P removal from inflow water containing high TP concentration by the SAV wetland and the importance of hydraulic regime to wetland performance.

Elementary Theory for Optimum Extraction of Space-Charge-Dominated Ion Beams from Plasma Boundaries

The problem of extracting space-charge-limited ion beams from spherical emission boundaries is analyzed for simple,two electrode,parallel-plate and spherical sector electrode systems by application of Langmuir-Blodgett theory with account taken for the divergent lens effect caused by the aperture in the extraction electrode.Results derived from simulation studies for the three electrode system,designed for use with the Oak Ridge National Laboratory ECR ion source,complement predictions made from elementary analytical theory with or without magnetic field in the extraction region of the source.Under minimum half- angular divergence(minimum emittance)conditions,the plasma emission boundary has an optimum curvature and the perveance,P,(i.e,current density,j+and extraction gap,d),has an optimum value for a given charge- state.From these studies,we find that the optimum perveance for any electrode system can be determined from the Child-Langmuir relation for the parallel-plate electrode system multiplied by a factor,F with value 0.49≤F≤1.

Equivalent Conditions of Dominated Splitting for Volume-Preserving Diffeomorphisms

We discuss the equivalent conditions of dominated splitting for conservative diffeomorphisms in C^1 topology.

Dominated Splitting Versus Small Angles

In this paper, we give a partial answer to the problem proposed by Lan Wen. Roughly speaking, we prove that for a fixed i, f has C^1 persistently no small angles if and only if f has a dominated splitting of index i on the C^1 i-preperiodic set P＊^1（f）. To prove this, we mainly use some important conceptions and techniques developed by Christian Bonatti. In the last section, we also give a characterization of the finest dominated splitting for linear cocvcles.