COUPLING OF ASSUMED STRESS FINITE ELEMENT AND BOUNDARY ELEMENT METHODS WITH STRESS-TRACTION EQUILIBRIUM

In this study, the stress based finite element method is coupled with the boundary element method in two different ways. In the first one, the ordinary distribution matrix is used for coupling. In the second one, the stress traction equilibrium is used at the interface line of both regions as a new coupling process. This new coupling procedure is presented without a distribution matrix. Several case studies are solved for the validation of the developed coupling procedure. The results of case studies are compared with the distribution matrix coupling, displacement based finite element method, assumed stress finite element method, boundary element method, ANSYS and analytical results whenever possible. It is shown that the coupling of the stress traction equilibrium with assumed stress finite elements gives as accurate results as those by the distribution matrix coupling.

A URI 4-NODE QUADRILATERAL ELEMENT BY ASSUMED STRAIN METHOD FOR NONLINEAR PROBLEMS

In this paper one-point quadrature'assumed strain'mixed element formulation based on the Hu-Washizu variational principle is presented.Special care is taken to avoid hourglass modes and volumetric locking as well as shear locking.The assumed strain fields are constructed so that those portions of the fields which lead to volumetric and shear locking phenomena are eliminated by projection,while the implementation of the proposed URI scheme is straightforward to suppress hour- glass modes.In order to treat geometric nonlinearities simply and efficiently,a corotational coordinate system is used.Several numerical examples are given to demonstrate the performance of the suggested formulation,including nonlinear static/dynamic mechanical problems.

Space Charge Effects in CSL Gauge——with previously assumed charge distribution

The "cascade static lens （CSL） gauge" has a high sensitivity（S） because the emitted electrons repeat the go and back oscillation before they are received by the electrodes. (S=18.6 Pa-1 (2480 Torr-1 in a

ASSUME用法译评

在英语语言文学中,对assume这个词的一般用法可散见于有关书籍。但传统英语对其描述甚为肤浅,缺乏深层次探讨,往往失之偏顿。本文拟从语言学角度对其主要用法特征.潜在语义作较为深入的研讨,以就教于前辈与同行。

Meeting the Climate Commitments

The 2024 UN Climate Change Conference(COP29)will convene from 11 to 22 November in Baku,Azerbaijan.This year’s conference assumes special significance due to conflicts in some regions,geopolitical tensions and heightened uncertainties in the world.World leaders are expected to report on the progress in implementing their climate commitments.

A hybrid LES (Large Eddy Simulation)/assumed sub-grid PDF (Probability Density Function) model for supersonic turbulent combustion

A hybrid LES (Large Eddy Simulation)/assumed sub-grid PDF (Probability Density Function) closure model has been devel-oped for supersonic turbulent combustion. Scalar transport equations for all species in a given chemical kinetic mechanism were solved, which are necessary in the supersonic combustion where the non-equilibrium chemistry is essentially involved. The clipped Gaussian PDF of temperature and multivariate ? PDF of composition were used to close the sub-grid chemical sources that appear in the conservation equations. The sub-grid variances of temperature and composition were constructed based on scale similarity approach. A semi-implicit approach based on the PDF model was proposed to tackle the resulting numerical stiffness associated with finite rate chemistry. The model was applied to simulate a supersonic, coaxial H2-air burner, where both the mean and rms (root mean square) results were compared with the experimental data. In general, good agree-ments were achieved, which indicated that the present sub-grid PDF method could work well in simulating supersonic turbu-lent combustion. Moreover, the calculation showed that the sub-grid fluctuations of temperature and major species in the combustion region were of the order of 10%-20% of their rms, while the sub-grid fluctuation of hydroxyl might be as high as 40%-50% of its rms.

John Bell Assumes Presidency of IH&RA

The Board of Directors of theInternational Hotel ＆ Restaurant Assn.hasannounced the election of John Bell,former Director General and CEO of theCaribbean Hotel Assn,to the globalassociation’s Presidency.The appointmenttook place at the IH&RA General Assemblyduring the organization’s 40th AnnualCongress,held in Cairo,Egypt.“John Bellis a hospitality industry executive ofinternational renown who put theCaribbean hospitality industy on the mapwhile at the leadership of CHA.”statedIH＆RA Chief Executive Officer.Alain-Philippe Feutre.“His proven expertise willgreatly benefit IH&RA.”

The Distribution of Zeros of Quasi-Polynomials

PROFESSOR Yitang Zhang, a number theorist at the University of California, Santa Barbara, USA, has posted a paper on arXiv [1] that hints at the possibility that he may have solved the Landau-Siegel zeros conjecture. He has claimed that he has disproved a weaker version of the Landau-Siegel zeroes conjecture, an important problem related to the hypothesis.The conjecture is that there are solutions to the zeta function that do not assume the form prescribed by the Riemann hypothesis. Inspired by his work, in this Perspective, we would like to discuss about the distribution of zeros of quasi-polynomials for linear time-invariant(LTI) systems with time delays.

THE STEPPE FRONTIERS OF PĀRSA: NEGOTIATING THE NORTHEASTERN BORDERLANDS OF THE TEISPID-ACHAEMENID EMPIRE

1.Introduction:a history of violence In the eyes of both ancients and moderns,the Central Asian frontier zone(s)of the Achaemenid Empire,here understood as the satrapies of Baktria,Sogdiana,Chorasmia,and the semi-desertic steppes to their north,has traditionally assumed the features of a liminal territory characterized by geopolitical instability and cultural alienation.

最古老的石器

Archaeologists in Kenya have dug up some of the oldest stone tools ever found,but who used them is a mystery.In the past,scientists assumed that our direct ancestors were the only toolmakers.But two big fossil teeth found along with the tools at the Kenyan site belong to an extinct human cousin known as Paranthropus,according to a study published in the journal Science.This adds to the evidence that our direct relatives may not have been the only tool users and makers during the Stone Age.

FUZZY ADAPTIVE CONTROL OF FLEXIBLE-LINK ROBOT MANIPULATOR

A fuzzy adaptive control method is proposed for a flexible robot manipulator. Due to the structure characteristics of the flexible manipulator, the vibration modes must be controlled to realize the high-precision tip position. The Lagrangian principle is utilized to model the dynamic function of the single-degree flexible manipulator incorporating the assumed modes method. Simulation results of the fuzzy adaptive control method in the location control and the trajectory tracking with different tip disturbances are presented and compared with the results of the classic PD control. It shows that the controller can obtain the stable and robust performance.

《英语词汇学》辅导(5)

Ⅰ.Each of the statements below is followed by four alternative answers.Choose the one that wouldbest complete the statement.1.Polysemy is a common feature peculiar to ___.A.English only B.Chinese only C.all natural languages D.some natural languages2.From the ____ point of view,polysemy is assumed to be the result of growth and development of thesemantic structure of one and same word.A.linguistic B.diachronic C.synchronic D.

Bifurcation and buckling analysis of a unilaterally confined self-rotating cantilever beam

A nonlinear dynamic model of a simple nonholonomic system comprising a self-rotating cantilever beam subjected to a unilateral locked or unlocked constraint is established by employing the general Hamilton＇s Variational Principle. The critical values, at which the trivial equilibrium loses its stability or the unilateral constraint is activated or a saddle-node bifurcation occurs, and the equilibria are investigated by approximately analytical and numerical methods. The results indicate that both the buckled equilibria and the bifurcation mode of the beam are different depending on whether the distance of the clearance of unilateral constraint equals zero or not and whether the unilateral constraint is locked or not. The unidirectional snap-through phenomenon （i.e. catastrophe phenomenon） is destined to occur in the system no matter whether the constraint is lockable or not. The saddle-node bifurcation can occur only on the condition that the unilateral constraint is lockable and its clearance is nonzero. The results obtained by two methods are consistent.

Exploring high-temperature superconductivity in hard matter close to structural instability

This paper discusses where and how high-temperature superconductors can be found.

On the Correct Form of the Saha Equation for Two-Temperature Plasmas

Two quite different Saha equations modified to a two-temperature plasma were proposed and employed in many literatures.In order to clear up this confusion phenomenon lasted for a few decades in the community of thermal plasma science and technology,this paper re-examines the thermodynamic derivation of the two-temperature Saha equations.It is pointed out that the modified Saha equation deduced by using the minimum Gibbs or Helmholtz free energy is incorrect for the two-temperature plasma.Instead,a more rigorous derivation is presented here from the basic thermodynamic principle that the entropy in an isolated system always assumes its maximum value at chemical equilibrium.

Earthquake loss estimation by using Gross Domestic Product and population data

In the traditional method of earthquake loss estimation, all the social wealthes are classified according to their structural type and occupational use. Inventory data is collected and the total loss is estimated from each facility class separately. For many regions of the world, however, the vast amount of data required by this method is difficult or impossible to obtain. The traditional method is also unable to estimate quickly the loss from an unexpected disaster earthquake. It is difficult to give the necessary risk information to help the government to rescue and relief the earthquake disaster. This paper proposes a simple estimation method of earthquake loss based on macroscopic economical index of Gross Domestic Product (GDP) and population distribution data. A preliminary nonlinear relation among hazard loss, seismic intensity and social wealth was developed by means of some earthquake disaster records during 1980～1995. This method was applied to analyze several assumed earthquakes. The preliminary analysis results show that the new method is effective and reasonable for quick assessment of earthquake loss.

Potential of kynurenine metabolites in drug development against neurodegenerative diseases

Reactive oxygen species(ROS)and kynurenines:Kynurenines represent a relatively heterogenous group of tryptophan metabolites(Figure 1 A).The amino acid tryptophan is metabolized in the humans by the kynurenine or serotonin pathway.For a long time,the kynurenine pathway was assumed primarily to constitute the source for nicotinamide-adenine dinucleotide phosphate,one of the most utilized redox active enzyme cofactors.