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Charm mixing from BABAR

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Chinese Physics C 2008年第6期32卷 463-469页

作者： n.neri BABAR Collaboration Universitàdi Pisa and INFNL.Bruno Pontecorvo 356127 PisaItaly

We present recent results from BABAR experiment for D^0-D^0mixing measurements. Mixing parameters can be measured in different ways using different D^ decay modes, here we discuss the most sensitive analyses such as D^0→ K^＋π^- where we had the first evidence of charm mixing, the measurement of the ratio of lifetimes of the decays D^0→ K^K^ and D^0→π^＋π^- relative to D^0→ K^-π^＋, the time dependent Dalitz plot analysis of D^0→K^＋π^-π^0. new limits on CP-violating time-integrated asymmetries in Do→ K^＋K^- and D^0→π^＋π^- are also discussed. The analyses presented are based on 384 fb^-1 data collected with the BABAR detector at the PEP-II asymmetric B Factory.

关键词： charm mixing flavor oscillations D^0 mesons BABAR

Influence of Various Parameters on Collapse Behaviour of Thin Cylinders

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上海交通大学学报 2004年第z2期38卷 1-7页

作者： n K Gupta Applied Mechanics Department ⅡT Delhi India - 110016

Axial compression experiments on as received aluminum tubes and tubes with wall thickness eccentricity incorporated by off centre machining showed that the eccentricity caused transition of their collapse mode from axisymmetric to diamond. The numerical simulation of the collapse phenomenon was undertaken using a static non-linear Finite Element Analysis in AnSYS, and results are found to compare well with the experimental load compression and energy absorption responses for axisymmetric concertina and non-axisymmetric diamond modes. Having validated the numerical model with experiments, it has been used to undertake a systematic study of the load - compression characteristics and collapse mode transitions of the tubes with varying eccentricities in wall thickness and boundary conditions, as well as the material properties.

关键词： thin tube collapse thickness eccentricity AnSYS axial compression

Minimization of methabenzthiazuron residues in leaching water using amended soils and photocatalytic treatment with TiO_2 and ZnO

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Journal of Environmental Sciences 2014年第4期26卷 757-764页

作者： Jos Fenoll Pilar Flores Pilar Hellín Joaquín Hern'andez Simón navarro Department of Food Quality Murcia Institute of Agri-Food Research and Development Department of Agricultural Chemistry Geology and Pedology School of Chemistry University of Murcia Campus Universitario de Espinardo

In the present work, potential groundwater pollution by methabenzthiazuron （MTBU） and the effect of three different amendments （composted sheep manure, composted pine bark and spent coffee grounds） on its mobility were investigated under laboratory conditions. The efficiency of ZnO and TiO2 suspensions in the photocatalytic degradation of MTBU in leaching water was also investigated. The relative and cumulative breakthrough curves were obtained from disturbed soil columns. The presence and/or addition of organic matter drastically reduced the movement of the herbicide. On other hand, photocatalytic experiments showed that the addition of ZnO and TiO2 strongly enhances the degradation rate of this herbicide compared with the results of photolytic experiments under artificial light. ZnO appeared to be more effective in MTBU oxidation than TiO2. The results obtained point to the interest of using organic wastes and heterogeneous photocatalysis for reducing the pollution of groundwater by pesticide drainage.

关键词： groundwater pollution organic amendment pesticide movement photocatalytic oxidation semiconductor oxides

On Integrable Roots in Split Lie Triple Systems

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Acta Mathematica Sinica,English Series 2009年第11期25卷 1759-1774页

作者： A.J.CALDERón MARTín Departamento de Matemáticas Universidad de Cádiz

We focus on the notion of an integrable root in the framework of split Lie triple systems T with a coherent 0-root space. As a main result, it is shown that if T has all its nonzero roots integrable, then its standard embedding is a split Lie algebra having all its nonzero roots integrable. As a consequence, a local finiteness theorem for split Lie triple systems, saying that whenever all nonzero roots of T are integrable then T is locally finite, is stated. Finally, a classification theorem for split simple Lie triple systems having all its nonzero roots integrable is given.

关键词： Lie triple system root split Lie algebra classification theory

Pulsed high-current discharge in water:adiabatic model of expanding plasma channel and acoustic wave

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Plasma Science and Technology 2022年第3期24卷 123-129页

作者： A KOZYREV A ZHERLITSYn n SEMEnIUK Institute of High-Current Electronics Russian Academy of SciencesTomsk 634055Russia

This paper presents the results of a theoretical and experimental study of the use of a pulsed discharge in water to obtain a strong acoustic wave in a liquid medium.A discharge with a current amplitude of 10 kA,a duration of 400 ns,and an amplitude pulsed power of 280 MW in water at atmospheric pressure created an expanding acoustic wave with an amplitude of more than 100 *** describe the formation of the discharge channel,an isothermal plasma model has been developed,which made it possible to calculate both the expansion dynamics of a high-current channel and the strong acoustic wave generated by *** calculations show that the number density of plasma in the channel reaches 10^(20) cm^(-3),while the degree of water vapor ionization is about 10%,and the channel wall extends with a velocity of 500 m s^(−1).The calculations for the acoustic wave are in good agreement with measurements.

关键词： plasma applications electrical discharge in water dense plasma channel

Quaternion methods and models of regular celestial mechanics and astrodynamics

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Applied Mathematics and Mechanics(English Edition) 2022年第1期43卷 21-80页

作者： Y.n.CHELnOKOV Institute of Precision Mechanics and Control Russian Academy of SciencesSaratov410031Russia

This paper is a review,which focuses on our work,while including an analysis of many works of other researchers in the field of quaternionic *** regular quaternion models of celestial mechanics and astrodynamics in the Kustaanheimo-Stiefel(KS)variables and Euler(Rodrigues-Hamilton)parameters are *** models are derived by the quaternion methods of mechanics and are based on the differential equations of the perturbed spatial two-body problem and the perturbed spatial central motion of a point *** paper also covers some applications of these *** and Scheifele are known to have doubted that quaternions and quaternion matrices can be used efficiently to regularize the equations of celestial ***,the author of this paper and other researchers refuted this point of view and showed that the quaternion approach actually leads to efficient solutions for regularizing the equations of celestial mechanics and *** paper presents convenient geometric and kinematic interpretations of the KS transformation and the KS bilinear relation proposed by the present *** general(compared with the KS equations)quaternion regular equations of the perturbed spatial two-body problem in the KS variables are *** equations are derived with the assumption that the KS bilinear relation was not *** main stages of the quaternion theory of regularizing the vector differential equation of the perturbed central motion of a point particle are presented,together with regular equations in the KS variables and Euler parameters,derived by the aforementioned *** also present the derivation of regular quaternion equations of the perturbed spatial two-body problem in the Levi-Civita variables and the Euler parameters,developed by the ideal rectangular Hansen coordinates and the orientation quaternion of the ideal coordinate *** paper also gives new results using quaternionic methods in the pertur

关键词： celestial mechanics astrodynamics perturbed spatial two-body problem central motion regularization Levi-Civita and Kustaanheimo-Stiefel(KS)variables Euler parameter quaternion

A methodological framework for improving air quality monitoring network *** to environment management

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Journal of Environmental Sciences 2021年第4期33卷 138-147页

作者： David Galán-Madruga Department of Atmospheric Pollution National Center for Environment HealthHealth Institute Carlos IIICtra.Majadahonda a Pozuelo km 2228220 MadridSpain

This work aims to provide a methodology framework which allows to improve the performance and efficiency of an air quality monitoring network(AQMn).It requires to be constituted by a minimum and reliable number of measurement ***,the AQMn efficiency should be assessed over time,as a consequence of the possible emergence of new emission sources of air pollutants,which could lead to variations on their spatial distribution within the target ***_(10)particles data monitored by the Community of Madrid's(Spain)AQMn between 2008 and 2017 were used to develop a methodology to optimize the AQMn *** annual spatial distribution of average PM_(10)levels over the studied period monitored by all current stations vs those more representative was provided by a geographic information system(GIS),and the percentage of similarity between both postulates was quantified using simple linear regression(>95%).As one innovative tool of this study,the practical application of the proposed methodology was validated using PM_(10)particles data measured by AQMn during 2007 and 2018,reaching a similitude degree higher than 95%.The influence of temporal variation on the proposed methodological framework was around 20%.The proposed methodology sets criteria for identifying non-redundant stations within AQMn,it is also able to appropriately assess the representativeness of fixed monitoring sites within an AQMn and it complements the guidelines set by European legislation on air pollutants monitoring at fixed stations,which could help to tackle efforts to improve the air quality management.

关键词： Air quality Ambient air monitoring network PM_(10)particles Redundant stations Optimization Environment management

InVESTIGATIOn OF DOMInAnT FREQUEnCIES In TRAnSITIOn REYnOLDS nUMBER RAnGE OF FLOW AROUnD A CIRCULAR CYLInDER PART I:EXPERIMEnTAL STUDY OF THE RELATIOn BETWEEn VORTEX SHEDDInG AnD TRAnSITIOn FREQUEnCIES

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Chinese Journal of Mechanical Engineering 2006年第3期19卷 159-167页

作者： AHMED n A School of Mechanical and Manufacturing Engineering University of new South Wales Sydney 2052 Australia

A comprehensive hot wire investigation of the flow around a circular cylinder is carried out in an 18＂ × 18＂ wind tunnel to look into the dominant frequencies at the stagnation, separation and separated shear layers in the transition Reynolds number range. The majority of the experiments are carried out at Reynolds number of 4.5×104, with additional transition frequency tests at Reynolds numbers of 2.9×104, 3.3×104 and 9.7×104 respectively. The results are analysed in terms of power spectral density. While the frequency associated with stagnation is found to be essentially due to vortex shedding, frequency doubling of vortex shedding is also evident in the separated shear layers. Two peaks associated with transition frequencies are detected and their possible implications are presented.

关键词： Vortex shedding Transition Separated flow Power spectral density

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Structure and Properties of Functionalized Polyfluorenone Containing Hetero Aromatic Side Chains

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Chinese Journal of Polymer Science 2014年第5期32卷 667-674页

作者： R.Venkatesan n.Somanathan n.Rajeswari Department of Printing Technology College of Engineering Guindy Anna University Polymer lab Central Leather Research institute

The optical properties of substituted fluorenones with diverse structures have been analyzed using molecular orbital calculations in order to understand the structure-property relations. Based on theoretical predictions, synthesis of some model compounds has been attempted. The experimentally obtained optical properties are in close agreement with the theoretically obtained results.

关键词： Conjugated polymer UV-Visible spectroscopy Band gap Structure and properties Molecular orbital calculations.