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Structural and Magnetic Properties of Chemically Synthesized Pd-Modified NiFe2O4 Nanoparticles

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Chinese Journal of Chemical Physics 2016年第2期29卷 245-248,I0002页

作者： shahid Aatiq shahid M. Ramay Asif Mahmood SairaRiaza Shahzad Naseem 巴基斯坦旁遮普邦大学固体物理卓越中心拉合尔100190 沙特阿拉伯沙特国王大学理学院物理与天文学系利雅得11421 沙特阿拉伯沙特国王大学工程学院化学工程系利雅得11421

Magnetic nanoparticles of NiFe2O4-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800℃ for 6 h in order to develop the crystalline phase. X-ray diffraction confirmed the spinel structure of the ferrite samples. Structural morphology and size of the nanoparticles were evaluated using a field emission scanning electron microscope. Magnetic hysteresis loops were obtained at 300 and 100 K using a physical properties measurement system. The value of saturation magnetization was observed to decrease at the temperatures with the increase of Pd contents up to 5% but then a sudden rise in saturation magnetization was observed for the addition of 10% Pd in NiFe2O4.

关键词： Magnetic nanoparticles Sol-gel auto-combustion Low temperature magneticproperty

Effect of Co substitution on the structural,electrical,and magnetic properties of Bi_(0.9)La_(0.1)FeO_3 by sol-gel synthesis

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International Journal of Minerals,Metallurgy and Materials 2013年第2期20卷 166-171页

作者： Ghulam Ali Saadat A.Siddiqi shahid M.Ramay shahid Atiq Murtaza Saleem Centre of Excellence in Solid State Physics University of the Punjab Interdisciplinary Research Centre in Biomedical Materials COMSATS Institute of Information Technology Chemical Engineering Department College of EngineeringKing Saud University

Cobalt （Co）-doped ***3 multiferroics were synthesized by a sol-gel method based on the auto- combustion technique. As-synthesized powder was examined using various characterization techniques to explore the effect of Co substitution on the properties of Bi0.9La0.1FeO3. X-ray diffraction reveals that Co-doped Bi0.9La0.1FeO3 preserves the perovskite-type rhombohedral structure of BiFeO3, and the composition without Co preserves the original structure of the phase; however, a second-phase Bi2Fe409 has been identified in all other compositions. Surface morphological studies were performed by scanning electron microscopy. Temperature-dependent resistivity of the samples reveals the characteristic insulating behavior of the multiferroic material. The resistivity is found to decrease with the increase both in temperature and Co content. Room temperature frequency-dependent dielectric measurements were also reported. Magnetic measurements show the enhancement in magnetization with the increase in Co content.

关键词： multiferroics cobalt doping microstructure electric properties magnetic properties sol-gel process

Accretion onto Charged Black Holes in Einstein and Massive Theories of Gravity

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Communications in Theoretical Physics 2019年第6期71卷 702-710页

作者： Abdul Jawad shahid Chaudhary Department of Mathematics COMSATS UniversityIslamabadLahore Campus-54000Pakistan Department of Mathematics Sharif College of Engineering and TechnologyLahore-54000Pakistan

The accretion process is being investigated onto some important black holes such as Born-Infeld-AdS black hole, non-linear charged black hole solution in AdS space-time and Einstein-Yang-Mills massive gravity in the presence of Born-Infeld nonlinear electrodynamics. We find out the relations of radial velocity, energy density and change of mass for mention black holes and analyze their behavior graphically for different values of equation of state parameters ω.We also examine the relations for critical speed for these black holes. It is observed that for different state parameters different fluids exhibit different evolutions in black holes backgrounds. The energy density of some fluids is negative or positive near the black hole while other fluids become cause to increase or decrease in black hole mass.

关键词： accretion black holes Einstein gravity massive gravity

Generalized Coherent States for Position-Dependent Effective Mass Systems

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Communications in Theoretical Physics 2016年第12期65卷 615-620页

作者： Naila Amir shahid Iqbal School of Electrical Engineering and Computer Sciences National University of Sciences and Technology School of Natural Sciences National University of Sciences and Technology

A generalized scheme for the construction of coherent states in the context of position-dependent effective mass systems has been presented. This formalism is based on the ladder operators and associated algebra of the system which are obtained using the concepts of supersymmetric quantum mechanics and the property of shape invariance. In order to exemplify the general results and to analyze the properties of the coherent states, several examples have been considered.

关键词： generalized coherent states supersymmetric quantum mechanics shape invariance ladder operators position-dependent effective mass systems non-linear oscillators Mandel parameter subPoissonian statistics

Barut–Girardello Coherent States for Nonlinear Oscillator with Position-Dependent Mass

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Communications in Theoretical Physics 2016年第7期65卷 41-48页

Using ladder operators for the non-linear oscillator with position-dependent effective mass, realization of the dynamic group SU(1,1) is presented. Keeping in view the algebraic structure of the non-linear oscillator, coherent states are constructed using Barut–Girardello formalism and their basic properties are discussed. Furthermore, the statistical properties of these states are investigated by means of Mandel parameter and second order correlation function. Moreover,it is shown that in the harmonic limit, all the results obtained for the non-linear oscillator with spatially varying mass reduce to corresponding results of the linear oscillator with constant mass.

关键词： position-dependent mass nonlinear oscillator Schdinger factorization Ladder operators su(1 1) algebra Barut–Girardello coherent states sub-poissonian statistics

On the roads to H1N1 pandemic era:drive safe and fearless using colour-coded masks

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Asian Pacific Journal of Tropical Medicine 2012年第4期5卷 333-334页

作者： M shahid Department of Microbiology Immunology & Infectious DiseasesCollege of Medicine & Medical SciencesArabian Gulf UniversityKingdom of Bahrain Section of Antimicrobial Resistance Research and Molecular Biology Department of MicrobiologyJawaharlal Nehru Medical College & HospitalAligarh Muslim UniversityAligarh-202002Uttar PradeshIndia

Notwithstanding the end of 2009 H1N1 pandemic,the threat for its revisit still persists and WHO has warned to remain *** that lime the situation was more panicky than *** this article,a suggestion to minimize the panic is provided by the usage of colour-coded masks and is proposed hereby as a "population segregation" approach in case of the revisit of HlNl or similar threatening respiratory viral infections.

关键词： H1N1 Respiratory viral infections Colour-coded masks Population segregation Public health

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

Total Fragmentation Cross Section of 158A GeV Lead Projectiles in Cu Target

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Chinese Physics Letters 2008年第9期25卷 3208-3211页

作者： Mukhtar Ahmed Rana shahid Manzoor Physics Division Directorate of Science PINSTECH PO Nilore Islamabad Pakistan

Total fragmentation cross section for the reaction 158A Pb ions ＋ Cu target is measured using the most sensitive track detector CR-39. Measured values are compared with calculations. Exposures of target-detector stack with 158A P5 projectiles are made at CERN-SPS beam facility. Results of calibration of CR-39 detector in a charge region （63 ≤ Z ≤ 83） are also reported, which can be used for high energy particle identification using CR-39 and in determination of partial charge changing cross sections. The charge resolution δz achieved by this technique is about 0.2e. A systematic dependence of total fragmentation cross section on target properties is revealed and the corresponding results are presented.

关键词： the power-law exponents precipitation durative abrupt precipitation change

A framework for coupled consolidation-desiccation behaviour of clay slurries

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International Journal of Mining Science and Technology 2018年第2期28卷 275-280页

作者： Faseel S.Khan shahid Azam Faculty of Engineering and Applied Science University of Regina

A framework is proposed to understand coupled consolidation-desiccation in clay slurries using effective stress and soil suction as state variables. Constitutive surfaces were derived from best-fit equations for reference curves where one state variable was kept at 1 kPa and the other was varied up to 10~6 *** indicated that volume compressibility comprises of apparent pre-consolidation up to 100 kPa beyond which a single best-fit curve is valid. Similarly, the theoretical virgin compression line(specific gravity dependant), indicated that both state variables have the same effect up to the air entry value(1000 kPa at a void ratio of 1.8) beyond which void ratio reduces more readily under effective stress than under soil suction. Likewise, hydraulic conductivity remained saturated up to the air entry value and varied from 10^(-9)m/s to 10^(-12)m/s. Finally, the unsaturated hydraulic conductivity correlated well with empirical relationship up to 10^(-14) m/s bevond which vapor flow became dominant.

关键词： Clay slurries Volume compressibility Hydraulic conductivity Constitutive surfaces