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The peculiar velocity and temperature profile of galaxy clusters

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Research in Astronomy and Astrophysics 2014年第6期14卷 667-672页

作者： Tabasum Masood Naseer iqbal Department of Physics Kashmir University Inter University Centre for Astronomy and Astrophysics IUCAA

Dynamical parameters like average velocity dispersion and temperature profile of galaxy clusters are determined using the theory of quasi-equilibrium ther- modynamics. The calculated results of velocity dispersion show a good agreement between theory and simulations with the results of velocity dispersion from Abdullah et al. An adaptive mesh refinement grid-based hybrid code has been used to carry out the simulations. Our results indicate that the average velocity dispersion profile of 20 Abell galaxy clusters falls in the range of 500 - 1000 km s^-1 and their temperature profile is of the order of 10^7 to 10^8 K calculated on the basis of kinetic theory. The data in the plot show a significant contribution from gravitating particles clustering together in the vicinity of the cluster center and beyond a certain region this veloc- ity dies out and becomes dominated by the Hubble flow due to which all the galaxy clusters in an expanding universe participate in Hubble expansion.

关键词： galaxies: clusters -- gravitation -- simulations

Spin and pseudospin symmetric Dirac particles in the field of Tietz-Hua potential including Coulomb tensor interaction

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Chinese Physics B 2013年第9期22卷 233-244页

作者： Sameer M. Ikhdair majid Hamzavi Department of Physics Faculty of ScienceAn-Najah National UniversityNew CampusJunaidNablusWest BankPalestine Department of Electrical and Electronic Engineering Near East University Department of Science and Engineering Abhar BranchIslamic Azad University

Approximate analytical solutions of the Dirac equation for Tietz-Hua （TH） potential including Coulomb-like tensor （CLT） potential with arbitrary spin-orbit quantum number K are obtained within the Pekeris approximation scheme to deal with the spin-orbit coupling terms K（K± 1）r^-2. Under the exact spin and pseudospin symmetric limitation, bound state energy eigenvalues and associated unnormalized two-component wave functions of the Dirac particle in the field of both attractive and repulsive TH potential with tensor potential are found using the parametric Nikiforov-Uvarov （NU） method. The cases of the Morse oscillator with tensor potential, the generalized Morse oscillator with tensor potential, and the non-relativistic limits have been investigated.

关键词： Dirac equation Tietz-Hua (TH) potential Coulomb-like tensor (CLT) potential generalizedMorse potential

Utilizing a new soil effective temperature scheme and archived satellite microwave brightness temperature data to estimate surface soil moisture in the Nagqu region, Tibetan Plateau of China

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Journal of Arid Land 2018年第1期10卷 84-100页

作者： TIAN Hui Mudassar iqbal Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Since the early 2000s, many satellite passive microwave brightness temperature （BT） archives, such as the Advanced Microwave Scanning Radiometer for the Earth Observing System （AMSR-E） BTs, have become the useful resources for assessing the changes in the surface and deep soil moistures over both arid and semi-arid regions. In this study, we used a new soil effective temperature （T scheme and the archived AMSR-E BTs to estimate surface soil moisture （SM） over the Nagqu region in the central Tibetan Plateau, China. The surface and deep soil temperatures required for the calculation of regional-scale T were obtained from outputs of the Community Land Model version 4.5 （CLM4.5）. In situ SM measurements at the CEOP-CAMP/Tibet （Coordinated Enhanced Observing Period Asia-Australia Monsoon Project on the Tibetan Plateau） experimental sites were used to validate the AMSR-E-based SM estimations at regional and single-site scales. Furthermore, the spatial distribution of monthly mean surface SM over the Nagqu region was obtained from 16 daytime AMSR-E BT observations in July 2004 over the Nagqu region. Results revealed that the AMSR-E-based surface SM estimations agreed well with the in situ-based surface SM measurements, with the root mean square error （RMSE） ranging from 0.042 to 0.066 m3/m3 and the coefficient of determination （R2） ranging from 0.71 to 0.92 during the nighttime and daytime. The regional surface soil water state map showed a clear spatial pattern related to the terrain. It indicated that the lower surface SM values occurred in the mountainous areas of the northern, mid-western and southeastern parts of Nagqu region, while the higher surface SM values appeared in the low elevation areas such as the Tongtian River Basin, Namco Lake and bog meadows in the central part of Nagqu region. Our analysis also showed that the new T^scheme does not require special fitting parameters or additional assumptions, which simplifies the data requirements for regional-scale ap

关键词： soil effective temperature archived AMSR-E brightness temperature CLM4.5 soil temperature output Cumulative Distribution Function (CDF) matching surface soil moisture Tibetan Plateau

Coherent States of Nonlinear Oscillators with Position-Dependent Mass:Temporal Stability and Fractional Revivals

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Communications in Theoretical Physics 2017年第8期68卷 181-190页

作者： Naila Amir Shahid iqbal School of Electrical Engineering and Computer Sciences National University of Sciences and Technology Department of Physics School of Natural Sciences National University of Sciences and Technology

We develop generalized coherent states for a class of nonlinear oscillators with position-dependent effective mass in the context of the Gazeau–Klauder formalism and discuss some of their properties. In order to investigate the temporal evolution we first explore the statistical properties by means of weighting distribution and the Mandel parameter. It is found that the temporal evolution of the coherent states may exhibit the phenomena of quantum revivals and fractional revivals for a particular choice of position-dependent mass oscillator.

关键词： position-dependent effective mass nonlinear oscillators Gazeau–Klauder coherent states Mandel parameter sub-Poissonian statistics temporal stability quantum revivals fractional revivals

Soliton formation in electron-temperature-gradient-driven magnetoplasma

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Plasma Science and Technology 2018年第2期20卷 82-86页

作者： M Yaqub KHAN Javed iqbal Department of Mathematics Riphah International University

Electron-temperature-gradient（ETG）-driven solitons are studied in a *** derive the linear dispersion relation and an admitted solitary wave solution Korteweg–de Vries-typeequation（Kd V）for the ETG mode in the nonlinear regime by using the Braginskii model and a *** is found that the ETG mode supports only rarefactive *** is also observed that the ratio of electron-to-ion temperature t=T T,e ithe ratio of gradient scale lengths h=L L,（en） Tand the magnetic field B affect both the amplitude and width of a *** is found that the soliton profile changes with variation in these *** apply the homotopy perturbation method to the derived Kd V *** is found this method is computationally attractive and the results are very *** work may be useful to study the low electrostatic modes in inhomogeneous electron–ion plasma with density and *** illustration,the model has been applied to tokamak plasma.

关键词： ETG mode KdV equation HPM

Influence of B source materials on the synthesis of TiB_2-Al_2O_3 nanocomposite powders by mechanical alloying

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International Journal of Minerals,Metallurgy and Materials 2013年第12期20卷 1214-1220页

作者： majid Abdellahi Javad Heidari Rahman Sabouhi Materials Engineering Department Islamic Azad University

An Al2O3-TiB2 nanocomposite was successfully synthesized by ball milling of Al, TiO2 and two B source materials of B2O3 （system （1）） and H3BO3 （system （2））. Phase identification of the milled samples was examined by Xray diffraction. The morphology and microstructure of the milled powders were monitored by scanning electron microscopy and transmission electron microscopy. It was found that the formation of this composite was completed after 15 and 30 h of milling time in systems （1） and （2）, respectively. More milling energy was required for the formation of this composite in system （2） due to the lubricant properties of HaBO3 and also its decomposition to HBO2 and B2O3 during milling. On the basis of X-ray diffraction patterns and thermodynamic calculations, this composite was formed by highly exothermic mechanically induced self-sustaining reactions （MSR） in both systems. The MSR mode took place around 9 h and 25 h of milling in systems （1） and （2）, respectively. At the end of milling （15 h for system （1） and 30 h for system （2）） the grain size of about 35-50 nm was obtained in both systems.

关键词： nanocomposites powders alumina titanium diboride mechanical alloying

Effects of external fields on a two-dimensional Klein-Gordon particle under pseudo-harmonic oscillator interaction

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Chinese Physics B 2012年第11期21卷 68-73页

作者： Sameer M.Ikhdair majid Hamzavi Physics Department Near East University Department of Basic Sciences Shahrood BranchIslamic Azad University

We study the effects of the perpendicular magnetic and Aharonov-Bohm （AB） flux fields on the energy levels of a two-dimensional （2D） Klein Gordon （KG） particle subjected to an equal scalar and vector pseudo-harmonic oscillator （PHO）. We calculate the exact energy eigenvalues and normalized wave functions in terms of chemical potential param- eter, magnetic field strength, AB flux field, and magnetic quantum number by means of the Nikiforov Uvarov （NU） method. The non-relativistic limit, PHO, and harmonic oscillator solutions in the existence and absence of external fields are also obtained.

关键词： Klein-Gordon equation two-dimensional pseudo-harmonic oscillator (PHO) potential,magnetic and Aharonov-Bohm (AB) flux fields Nikiforov-Uvarov method

Multi-objective optimization of molten carbonate fuel cell system for reducing CO2 emission from exhaust gases

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Frontiers in Energy 2015年第1期9卷 106-114页

作者： Ramin ROSHANDEL majid ASTANEHI Farzin GOLZAR Department of Energy Engineering Sharif University of TechnologyTehran 14565114 Iran

The aim of this paper is to investigate the implementation of a molten carbonate fuel cell （MCFC） as a CO2 separator. By applying multi-objective optimization （MOO） using the genetic algorithm, the optimal values of operating load and the corresponding values of objective functions are obtained. Objective functions are minimiza- tion of the cost of electricity （COE） and minimization of CO2 emission rate. CO2 tax that is accounted as the pollution-related cost, transforming the environmental objective to the cost function. The results show that the MCFC stack which is fed by the syngas and gas turbine exhaust, not only reduces CO2 emission rate, but also produces electricity and reduces environmental cost of the system.

关键词： molten carbonate fuel cell (MCFC) multi-objective optimization (MOO) Pareto curve geneticalgorithm CO2 separation

Computational Methods for Single-cell DNA Methylome Analysis

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Genomics, Proteomics & Bioinformatics 2023年第1期21卷 48-66页

作者： Waleed iqbal Wanding Zhou Center for Computational and Genomic Medicine Children’s Hospital of PhiladelphiaPhiladelphiaPA 19104USA Department of Pathology and Laboratory Medicine University of PennsylvaniaPhiladelphiaPA 19104USA

Dissecting intercellular epigenetic differences is key to understanding tissue *** advances in single-cell DNA methylome profiling have presented opportunities to resolve this heterogeneity at the maximum *** these advances enable us to explore frontiers of chromatin biology and better understand cell lineage relationships,they pose new challenges in data processing and *** review surveys the current state of computational tools developed for single-cell DNA methylome data *** discuss critical components of single-cell DNA methylome data analysis,including data preprocessing,quality control,imputation,dimensionality reduction,cell clustering,supervised cell annotation,cell lineage reconstruction,gene activity scoring,and integration with transcriptome *** also highlight unique aspects of single-cell DNA methylome data analysis and discuss how techniques common to other single-cell omics data analyses can be adapted to analyze DNA ***,we discuss existing challenges and opportunities for future development.

关键词： Single-cell genomics Bioinformatics DNA methylation Computational tool Epigenetics