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Titanium Alloy Surface Modification by a Spatio-Temporal Atmospheric Pressure DBD Afterglow

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Plasma Science and Technology 2007年第6期9卷 670-673页

作者： E.PANOUSIS f.clement J.f.LOISEAU N.SPYROU B.HELD J.LARRIEU f.GUERTON Laboratory of Gas Electronics and Plasmas-Pau University 64000 PauFrance Electrotechnic Materials LaboratoryUniversity of Patras26500 Patras-RioGreece Laboratory of Gas Electronics and Plasmas-Pau University 64000 PauFrance Electrotechnic Materials Laboratory University of Patras26500 Patras-RioGreece Laboratoire Interdisciplinaire de Spectroscopie Electronique University of Namur5000 NamurBelgium

The experimental work reported here is devoted to the study of the modifications inflicted on the surface of titanium alloy specimens by an atmospheric pressure dielectric barrier discharge（DBD） reactor in both spatial and temporal afterglow conditions. A commercially available （AcXys Technologies） modified reactor system was used for the surface treatment of the TiA6V4 titanium alloy that is widely used in the aeronautical industry. Wettability surface characterisation and XPS analyses are performed to give a macroscopic and microscopic insight to the surface modifications. Best operating conditions, at constant input energy, were obtained for a duty cycle equal to 10%.

关键词： DBD titanium alloy atmospheric pressure

Averaging in SU(2) open quantum random walk

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Chinese Physics B 2014年第3期23卷 109-111页

作者： clement Ampadu 31 Carrolton Road Massachusetts Boston 02132 USA

We study the average position and the symmetry of the distribution in the SU（2） open quantum random walk （OQRW）. We show that the average position in the central limit theorem （CLT） is non-uniform compared with ... 详细信息

关键词： open quantum random walk central limit theorem average position SU(2) operator

Brun-Type formalism for Decoherence in Two-Dimensional Quantum Walks

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Communications in Theoretical Physics 2012年第1期57卷 41-55页

作者： clement Ampadu 31 Carrolton Road BostonMassachusetts02132USA

We study decoherence in the quantum walk on the *** generalize the method of decoherent coin quantum walk,introduced by [***,et al.,***.A 67(2003) 032304],which could be applicable to all sorts of decoherence in two-dimensional quantum walks,irrespective of the unitary transformation governing the *** an application we study decoherence in the presence of broken line noise in which the quantum walk is governed by the two-dimensional Hadamard operator.

关键词： coin-position decoherence quantum random walk coin decoherence

Return Probability of the Open Quantum Random Walk with Time-Dependence

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Communications in Theoretical Physics 2013年第5期59卷 563-567页

作者： clement Ampadu 31 Carrolton Road Boston Massachusetts 02132 USA

We study the open quantum random walk (OQRW) with time-dependence on the one-dimensional lattice space and obtain the associated limit distribution. As an application we study the return probability of the OQRW. We al... 详细信息

关键词： open quantum random walk return probability limit theorem central limit theorem average time

Return Probability of the fibonacci Quantum Walk

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Communications in Theoretical Physics 2012年第8期58卷 220-224页

作者： clement AMPADU 31 Carrolton Road Boston Massachusetts 02132 USA

In this paper the return probability of the one-dimensional discrete-time quantum walk is studied. We derive probabilistic formulas for the return probability related to the quantum walk governed by the fibonacci coin.

关键词： return probability fibonacci transformation quantum random walk

Kinetic and thermodynamic studies on partitioning of polychlorinated biphenyls (PCBs) between aqueous solution and modeled individual soil particle grain sizes

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Journal of Environmental Sciences 2019年第2期31卷 100-110页

作者： Gbadebo clement Adeyinka Brenda Moodley School of Chemistry and Physics College of AgricultureEngineering and SciencesUniversity of KwaZulu-Natal

The significance of soil mineral properties and secondary environmental conditions such as pH, temperature, ionic strength and time in the partitioning of eight selected polychlorinated biphenyl(PCB) congeners between aqueous solution and soil particles with different grain sizes was studied. The mineral properties of a model soil sample were determined, and Brunauer–Emmett–Teller(BET) adsorption–desorption isotherms were employed to observe the surface characteristics of the individual modeled soil *** adsorption experiments were conducted to determine the sorption of PCBs onto soil particles of different sizes. The results revealed that the sorption of PCB congeners onto the soil was dependent on the amount of soil organic matter, surface area, and pore size distribution of the various individual soil particles. Low pH favored the sorption of PCBs,with maximum sorption occurring between pH 6.5 and 7.5 with an equilibration period of 8 *** in the ionic strength were found to be less significant. Low temperature favored the sorption of PCBs onto the soil compared to high temperatures. Thermodynamic studies showed that the partition coefficient(K_d) decreased with increasing temperature, and negative and low values of ΔH° indicated an exothermic physisorption process. The data generated is critical and will help in further understanding remediation and cleanup strategies for polluted water.

关键词： Partitioning PCBs Soil particle grain sizes Kinetics Thermodynamic studies pH

A time series for monitoring vegetation activity and phenology at 10-daily time steps covering large parts of South America

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International Journal of Digital Earth 2011年第5期4卷 365-386页

作者： clement Atzbergera Paul HCEilers Joint Research Centre of the European Commission(JRC) Institute for the Protection and Security of the CitizenMARS unitVia Enrico Fermi 274921027 IspraItaly Department of Biostatistics Erasmus Medical CentreDr.Molewaterplein 503015 GE RotterdamThe Netherlands

It is widely accepted that natural resources should only be sustainably exploited and utilized to effectively preserve our planet for future *** better manage the natural resources,and to better understand the closely linked Earth systems,the concept of Digital Earth has been strongly promoted since US Vice President Al Gore’s speech in *** core element of Digital Earth is the use and integration of remote sensing *** satellite imagery can cover the entire globe repeatedly at a sufficient high-spatial resolution to map changes in land cover and land use,but also to detect more subtle changes related for instance to climate *** uncover global change effects on vegetation activity and phenology,it is important to establish high quality time series characterizing the past situation against which the current state can be *** the present study we describe a time series of vegetation activity at 10-daily time steps between 1998 and 2008 covering large parts of South America at 1 km spatial *** emphasis was put on noise *** carefully filtered time series of vegetation indices can be used as a benchmark and for studying vegetation dynamics at a continental *** temporal smoothing,subtle spatio-temporal patterns in vegetation composition,density and phenology would be hidden by atmospheric noise and undetected *** noise is immanent in data that have undergone solely a maximum value *** the present study,the Whittaker smoother(WS)was applied to a SPOT VGT time *** WS balances the fidelity to the observations with the roughness of the smoothed *** algorithm is extremely fast,gives continuous control over smoothness with only one parameter,and interpolates *** filtering efficiently removed the negatively biased noise present in the original data,while preserving the overall shape of the curves showing vegetation growth and *** variog

关键词： :digital earth remote sensing global environmental change SPOT VGT Whittaker smoother NDVI seasonality earth observation global data bases image processing natural resources vegetation indices

Dibaryons: Molecular versus compact hexaquarks

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Chinese Physics C 2021年第2期45卷 23-38页

作者： H.clement T.Skorodko Physikalisches Institut der Universität Tübingen and Kepler Center for Astro and Particle Physics University of TübingenAuf der Morgenstelle 14D-72076 TübingenGermany

Hexaquarks constitute a natural extension of complex quark systems,just as tetra-and pentaquarks *** this end,the current status of d^(*)(2380)in both experiment and theory is *** high-precision meas-urements in the nucleon-nucleon channel and analyses thereof have established d^(*)(2380)as an indisputable reson-ance in the long-sought dibaryon *** features of this I(J^(P))=0(3^(+))state are its narrow width and deep binding relative to the 0(1232)0(1232)*** decay branchings favor theoretical calculations predict-ing a compact hexaquark nature of this *** review the current status of experimental and theoretical studies on d^(*)(2380)as well as new physics aspects it may bring in *** addition,we review the situation at the 0(1232)N and N^(*)(1440)N thresholds,where evidence for a number of resonances of presumably molecular nature has been found-similar to the situation in charmed and beauty ***,we briefly discuss the situation of dibaryon searches in the flavored quark sectors.

关键词： dibaryon hexaquark molecule

Species Distribution Modelling performance and its implication for Sentinel-2-based prediction of invasive Prosopis juliflora in lower Awash River basin, Ethiopia

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Ecological Processes 2021年第1期10卷 250-265页

作者： Nurhussen Ahmed clement Atzberger Worku Zewdie Department of Remote Sensing Entoto Observatory and Research CenterEthiopian Space Science and Technology Institute(ESSTI)Addis AbabaEthiopia. Department of Geography and Environmental Studies Wollo UniversityDessieEthiopia. Institute of Geomatics University of Natural Resources and Life SciencesVienna(BOKU)Peter JordanStraße 821190 ViennaAustria.

Background:Species Distribution Modelling(SDM)coupled with freely available multispectral imagery from Sentinel-2(S2)satellite provides an immense contribution in monitoring invasive ***,attempts to evaluate the performances of SDMs using S2 spectral bands and S2 Radiometric Indices(S2-RIs)and biophysical variables,in particular,were ***,this study aimed at evaluating the performance of six commonly used SDMs and one ensemble model for S2-based variables in modelling the current distribution of Prosopis juliflora in the lower Awash River basin,***-five variables were computed from Sentinel-2B level-2A,and out of the variables,twelve significant variables were selected using Variable Inflation factor(VIf).A total of 680 presence and absence data were collected to train and validate variables using the tenfold bootstrap replication approach in the R software“sdm”*** performance of the models was evaluated using sensitivity,specificity,True Skill Statistics(TSS),kappa coefficient,area under the curve(AUC),and ***:Our findings demonstrated that except bioclim all machine learning and regression models provided successful *** the tested models,Random forest(Rf)performed better with 93%TSS and 99%AUC followed by Boosted Regression Trees(BRT),ensemble,Generalized Additive Model(GAM),Support Vector Machine(SVM),and Generalized Linear Model(GLM)in decreasing *** relative influence of vegetation indices was the highest followed by soil indices,biophysical variables,and water indices in decreasing *** to Rf prediction,16.14%(1553.5 km^(2))of the study area was invaded by the alien ***:Our results highlighted that S2-RIs and biophysical variables combined with machine learning and regression models have a higher capacity to model invasive species ***,the use of machine learning algorithms such as Rf algorithm is highly essential for remote sensing-based inva

关键词： Biophysical processors Prosopis juliflora Radiometric indices Remote sensing Sentinel-2 Species Distribution Modelling