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Potential distribution around a test charge in a positive dust-electron plasma

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Frontiers of physics 2016年第3期11卷 133-141页

作者： s. ali National Centre for Physics (NCP) at Quaid-e-Azam University Campus Shahdra Valley Road Islamabad 44000 Pakistan

The electrostatic potential caused by a test-charge particle in a positive dust-electron plasma is studied, accounting for the d^Lst-charge fluctuations associated with ultraviolet photoelectron and thermionic emissions. For this purpose, the set of Vlasov-Poisson equations coupled with the dust charging equation is solved by using the space-time Fourier transform technique. As a consequence, a modified dielectric response function is obtained for dust-acoustic waves in a positive dust-electron plasma. By imposing certain conditions on the velocity of the test charge, the electrostatic potential is decomposed into the Deby^Hiickel （DH）, wake-field （WF）, and far-field （FF） potentials that are significantly modified in the limit of a large dust-charge relaxation rate both analytically and numerically. The results can be helpful for understanding dust crystallization/coagulation in two- component plasmas, where positively charged dust grains are present.

关键词： dusty plasmas dust charge fluctuations positively charged dusty plasma shielding anddynamical potentials

Newtonian heating in stagnation point flow of Burgers fluid

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Applied Mathematics and Mechanics(English Edition) 2015年第1期36卷 61-68页

作者： T.HAYAT s.ali M.AWAIs M.s.ALHUTHali Department of Mathematics Quaid-i-Azam University Nonlinear Analysis and Applied Mathematics (NAAM) Research Group Faculty of Science King Abdulaziz University Faculty of Engineering sciences Ghulam Ishaq Khan Institute of Engineering Sciences and Technology Department of Mathematics COMSATS Institute of Information Technology

The Newtonian heating effects in the stagnation point flow of a Burgers fluid are addressed in this paper. The boundary layer flow problems are stated in the spatial domain from zero to infinity. The solution expressions for the velocity and the temperature are obtained and examined for the influential variables. The tabulated values show comparison with the previous results. It is observed that the obtained results are in good agreement with the existing results in limiting sense.

关键词： Burgers fluid Newtonian heating series solutions

Nonplanar Electrostatic solitary Waves in a Relativistic Degenerate Dense Plasma

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Communications in Theoretical Physics 2013年第4期59卷 479-483页

作者： Ata-ur-Rahman A. Mushtaq s. ali A. Qamar Institute of Physics & Electronics University of Peshawar National Center for Physics Shahdrah Valley Road Department of Physics Abdul Wali Khan University

By employing the reductive perturbation technique, the propagation of cylindrical and spherical ion acoustic solitary waves is studied in an unmagnetized dense relativistic plasma, consisting of relativistically degenerate electrons and cold fluid ions. A modified Korteweg-de-Vries equation is derived and its numerical solutions have been analyzed to identify the basic features of electrostatic solitary structures that may form in such a degenerate Fermi plasma. Different degrees of relativistic electron degeneracy are discussed and compared. It is found that increasing number density leads to decrease the amplitude the width of the ion acoustic solitary wave in both the cylindrical and spherical geometries. The relevance of the work to the compact astrophysical objects, particularly white dwarfs is pointed out.

关键词：稠密等离子体相对论电子孤立波静电非平面退化扰动技术波的传播

Optoelectronic Response of GeZn_(2)O_(4) through the Modified Becke-Johnson Potential

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Chinese Physics Letters 2012年第9期29卷 142-146页

作者： Iftikhar Ahmad B.Amin M.Maqbool s.Muhammad G.Murtaza s.ali N.A.Noor Department of Physics University of MalakandPakistan Materials Modeling Lab Department of PhysicsHazara University21300Pakistan Department of Physics and Astronomy Ball State UniversityIndiana47306-0505USA Department of Physics Islamia College UniversityPeshawarPakistan Department of Physics University of the PunjabQuaid-e-Azam Campus54590Pakistan

A first-principles technique capable of describing the nearly excited states of semiconductors and insulators,namely the modified Becke–Johnson(mBJ)potential approximation,is used to investigate the electronic band structure and optical properties of spinel oxides:GeZn_(2)O_(4).The predicted band gaps using the mBJ approximation are significantly more accurate than the proposed previous theoretical work using the common LDA and GGA.Band gap dependent optical parameters,like the dielectric constant,index of refraction,reflectivity and optical conductivity are calculated and analyzed.The results from the dielectric constant shows that the numerical value of the static dielectric,after dropping constantly,becomes less than zero and the material exhibits metallic behavior.The refractive index also drops below unity for photons higher than 18 eV,which indicates that the velocities of incident photons are greater than the velocity of light.However,these phenomena can be explained by the fact that a signal must be transmitted as a wave packet rather than a monochromatic wave.This comprehensive theoretical study of the optoelectronic properties predicts that these materials can effectively be used in optical devices.

关键词： wave. dielectric approximation

Performance and calibration of quark/gluon-jet taggers using 140 fb^(-1) of pp collisions at √s=13 TeV with the ATLAs detector

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Chinese Physics C 2024年第2期48卷 1-25页

作者： G. Aad B. Abbott K. Abeling N.J. Abicht s.H. Abidi A. Aboulhorma H. Abramowicz H. Abreu Y. Abulaiti B.s. Acharya C. Adam Bourdarios L. Adamczyk s.V. Addepalli M.J. Addison J. Adelman A. Adiguzel T. Adye A.A. Affolder Y. Afik M.N. Agaras J. Agarwala A. Aggarwal C. Agheorghiesei A. Ahmad F. Ahmadov W.s. Ahmed s. Ahuja X. Ai G. Aielli A. Aikot M. Ait Tamlihat B. Aitbenchikh I. Aizenberg M. Akbiyik T.P.A. Åkesson A.V. Akimov D. Akiyama N.N. Akolkar K. Al Khoury G.L. Alberghi J. Albert P. Albicocco G.L. Albouy s. Alderweireldt M. Aleksa I.N. Aleksandrov C. Alexa T. Alexopoulos F. Alfonsi M. Algren M. Alhroob B. ali H.M.J. ali s. ali s.W. alibocus M. aliev G. alimonti W. Alkakhi C. Allaire B.M.M. Allbrooke J.F. Allen C.A. Allendes Flores P.P. Allport A. Aloisio F. Alonso C. Alpigiani M. Alvarez Estevez A. Alvarez Fernandez M. Alves Cardoso M.G. Alviggi M. Aly Y. Amaral Coutinho A. Ambler C. Amelung M. Amerl C.G. Ames D. Amidei s.P. Amor Dos santos K.R. Amos V. Ananiev C. Anastopoulos T. Andeen J.K. Anders s.Y. Andrean A. Andreazza s. Angelidakis A. Angerami A.V. Anisenkov A. Annovi C. Antel M.T. Anthony E. Antipov M. Antonelli F. Anulli M. Aoki T. Aoki J.A. Aparisi Pozo M.A. Aparo L. Aperio Bella C. Appelt A. Apyan N. Aranzabal s.J. Arbiol Val C. Arcangeletti A.T.H. Arce E. Arena J-F. Arguin s. Argyropoulos J.-H. Arling O. Arnaez H. Arnold G. Artoni H. Asada K. Asai s. Asai N.A. Asbah J. Assahsah K. Assamagan R. Astalos s. Atashi R.J. Atkin M. Atkinson H. Atmani P.A. Atmasiddha K. Augsten s. Auricchio A.D. Auriol V.A. Austrup G. Avolio K. Axiotis G. Azuelos D. Babal H. Bachacou K. Bachas A. Bachiu F. Backman A. Badea P. Bagnaia M. Bahmani A.J. Bailey V.R. Bailey J.T. Baines L. Baines O.K. Baker E. Bakos D. Bakshi Gupta V. Balakrishnan R. Balasubramanian E.M. Baldin P. Balek E. Ballabene F. Balli L.M. Baltes W.K. Balunas J. Balz E. Banas M. Bandieramonte A. Bandyopadhyay s. Bansal L. Barak M. Barakat E.L. Barberio D. Barberis M. Barbero M.Z. Barel K.N. Barends T. Barillari M-s. Barisits T. Barklow P. Baron D.A. Baron Mo The ATLAs Collaboration

The identification of jets originating from quarks and gluons,often referred to as quark/gluon tagging,plays an important role in various analyses performed at the Large Hadron Collider,as standard Model measurements and searches for new particles decaying to quarks often rely on suppressing a large gluon-induced background.This paper describes the measurement of the efficiencies of quark/gluon taggers developed within the ATLAs Collaboration,using √s=13 TeV proton–proton collision data with an integrated luminosity of 140 fb^(-1) collected by the ATLAs experiment.Two taggers with high performances in rejecting jets from gluon over jets from quarks are studied:one tagger is based on requirements on the number of inner-detector tracks associated with the jet,and the other combines several jet substructure observables using a boosted decision tree.A method is established to determine the quark/gluon fraction in data,by using quark/gluon-enriched subsamples defined by the jet pseudorapidity.Differences in tagging efficiency between data and simulation are provided for jets with transverse momentum between 500 GeV and 2 TeV and for multiple tagger working points.

关键词： ATLAs JET QUARK GLUON TAGGING

Big data challenge for monitoring quality in higher education institutions using business intelligence dashboards

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Journal of Electronic science and Technology 2024年第1期22卷 25-41页

作者： ali sorour Anthony s.Atkins Faculty of Digital TechnologyInnovationand BusinessStaffordshire UniversityStoke-on-TrentST42DEUnited Kingdom

As big data becomes an apparent challenge to handle when building a business intelligence(BI)system,there is a motivation to handle this challenging issue in higher education institutions(HEIs).Monitoring quality in HEIs encompasses handling huge amounts of data coming from different sources.This paper reviews big data and analyses the cases from the literature regarding quality assurance(QA)in HEIs.It also outlines a framework that can address the big data challenge in HEIs to handle QA monitoring using BI dashboards and a prototype dashboard is presented in this paper.The dashboard was developed using a utilisation tool to monitor QA in HEIs to provide visual representations of big data.The prototype dashboard enables stakeholders to monitor compliance with QA standards while addressing the big data challenge associated with the substantial volume of data managed by HEIs’QA systems.This paper also outlines how the developed system integrates big data from social media into the monitoring dashboard.

关键词： Big data Business intelligence(BI) Dashboards Higher education(HE) Quality assurance(QA) social media

Pharmacological insights into Chukrasia velutina bark:Experimental and computer-aided approaches

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Animal Models and Experimental Medicine 2022年第4期5卷 377-388页

作者： Israt Jahan shahenur Alam sakib Najmul Alam Mohuya Majumder sanjida sharmin A.s.M.ali Reza Department of Pharmacy International Islamic University ChittagongChittagongBangladesh Department of Pharmacy East West UniversityDhakaBangladesh

Background:Chukrasia velutina is an enthnomedicinally used plant reported to have significant medicinal values.The present study aimed to explore the pharmacological activities of bark methanol extract using in vitro,in vivo and in silico models.Methods:The study was designed to investigate the pharmacological effects of methanol extract of Chukrasia velutina bark(MECVB)through in vitro,in vivo and in silico assays.Analgesic activity was tested using formalin-i nduced nociception and acetic acid-i nduced writhing assays while the antipyretic effect was tested using yeast-i nduced hyperthermia in mice model.The antioxidant effect was tested using the DPPH and reducing power assay and the cytotoxic screening was tested using the brine shrimp lethality bioassay.In addition,in silico studies were conducted using computer aided methods.Results:In the acetic acid-i nduced writhing assay,the extract showed 28.36%and 56.16%inhibition of writhing for doses of 200 and 400 mg/kg,respectively.Moreover,a dose-dependent formalin-i nduced licking response was observed in both early and late phase.In yeast-i nduced pyrexia,the MECVB exhibited(pstrated an ICvalue of 78.86μg/ml compared with ascorbic acid(IC23.53μg/ml)in the DPPH scavenging assay.The compounds sitosterol,5,7-dimethoxycoumarin and scopoletin were seen be effective in molecular docking scores against COX-I(2OYE),COX-II(6COX)and human peroxiredoxin 5(1HD2).In ADME/T analysis,5,7-dimethoxycoumarin and scopoletin satisfied Lipinski’s rule of five and thus are potential drug candidates.Conclusion:The bark of Chukrasia velutina showed significant analgesic and antipyretic properties and is a potential source of natural anti-oxidative agents.

关键词： anti-nociceptive antioxidant antipyretic Chukrasia velutina cytotoxicity

Big data technology in infectious diseases modeling,simulation,and prediction after the COVID-19 outbreak

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智慧医学(英文) 2023年第2期3卷 85-96页

作者： Honghao shi Jingyuan Wang Jiawei Cheng Xiaopeng Qi Hanran Ji Claudio J struchiner Daniel AM Villela Eduard V Karamov ali s Turgiev school of Computer science and Engineering Beihang UniversityBeijing 100191China Center for Global Public Health Chinese Center for Disease Control and PreventionBeijing 102211China Fundação Getúlio Vargas Rio de JaneiroBrazil Instituto de Medicina social Hesio Cordeiro Universidade do Estado do Rio de JaneiroRio de JaneiroBrazil Programa de Computação Científica Fundação Oswaldo CruzRio de JaneiroBrazil Gamaleya National Research Center for Epidemiology and Microbiology of the Russian Ministry of Health Russia National Medical Research Center of Phthisiopulmonology and Infectious Diseases of the Russian Ministry of Health Russia

After the outbreak of COVID-19,the interaction of infectious disease systems and social systems has challenged traditional infectious disease modeling methods.starting from the research purpose and data,researchers im-proved the structure and data of the compartment model or used agents and artificial intelligence based models to solve epidemiological problems.In terms of modeling methods,the researchers use compartment subdivi-sion,dynamic parameters,agent-based model methods,and artificial intelligence related methods.In terms of factors studied,the researchers studied 6 categories:human mobility,nonpharmaceutical interventions(NPIs),ages,medical resources,human response,and vaccine.The researchers completed the study of factors through modeling methods to quantitatively analyze the impact of social systems and put forward their suggestions for the future transmission status of infectious diseases and prevention and control strategies.This review started with a research structure of research purpose,factor,data,model,and conclusion.Focusing on the post-COVID-19 infectious disease prediction simulation research,this study summarized various improvement methods and analyzes matching improvements for various specific research purposes.

关键词： Infectious disease model Data embedding social system Dynamic Modeling the social systems

Effects of electron trapping on nonlinear electron-acoustic waves excited by an electron beam via particle-in-cell simulations

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Plasma science and Technology 2019年第5期21卷 93-101页

作者： A A ABID 陆全明陈华岳柯阳光 s ali 王水 CAs Key Laboratory of Geospace Environment Department of Geophysics and Planetary ScienceUniversity of Science and Technology of ChinaHefei 230026People's Republic of China National Centre for Physics(NCP)at Quaid-e-Azam University Campus Shahdra Valley Road.Islamabad 44000Pakistan Hefei National Laboratory for Physical sciences at the Microscale and Department of Physics University of Science and Technology of ChinaHefei 230026People's Republic of China

By performing one-dimensional particle-in-cell simulations,the nonlinear effects of electronacoustic(EA)waves are investigated in a multispecies plasma,whose constituents are hot electrons,cold electrons,and beam electrons with immobile neutralized positive ions.Numerical analyses have identified that EA waves with a sufficiently large amplitude tend to trap cold electrons.Because EA waves are dispersive,where the wave modes with different wavenumbers have different phase velocities,the trapping may lead to the nlixing of cold electrons.The cold electrons finally get thermalized or heated.The investigation also shows that the excited EA waves give rise to a broad range of wave frequencies,which may be helpful for understanding the broadband-electrostatic-noise spectrum in the Earth's auroral region.

关键词： electron acoustic waves cold electrons trapping particle-in-cell(PIC)simulation