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Synthesis and Characterization of Alkaline-Earth Metal (Ca, Sr, and Ba) Doped Nanodimensional LaMnO_(3) Rare-Earth Manganites

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Chinese Physics Letters 2013年第7期30卷 217-220页

作者： Asma khalid Saadat Anwar Siddiqi Affia Aslam School of Physics University of MelbourneParkville VIC 3010Australia Interdisciplinary Research Centre in Biomedical Materials COMSATS Institute of Information TechnologyDefence RoadOff Raiwind RoadLahore-54700Pakistan Department of Physics University of HailHail-30055Saudi Arabia

The substitution of divalent cations of alkaline-earth elements in nanodimensional structures of rare-earth manganites produces advanced materials with potential electrical and magnetic functionalities.A systematic investigation of La_(0.65)A_(0.35)MnO_(3)(A=Ca,Sr,Ba)materials synthesized with a modified citrate route adopting ethanol dehydration has been *** structural and morphological analyses are carried out by using x-ray diffraction and scanning electron microscopy,*** measurements are performed in variation with temperature to study the electrical transport properties which are found to vary with the size of the A-site cationic *** temperature magnetic measurements are carried out to investigate the type of magnetic phase present in *** stability of the magnetic phase and coercivity are found to be dependent on the size of nanocrystallites.

关键词： materials. earth dimensional

Symmetry solutions of a nonlinear elastic wave equation with third-order anharmonic corrections

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Applied Mathematics and Mechanics(English Edition) 2009年第8期30卷 1017-1026页

作者： M.Tahir Mustafa khalid Masood Department of Mathematics and Statistics King Fahd University of Petroleum and MineralsDhahran 31261 Saudi Arabia Department of Mathematics Hafr Al-Batin Community College King Fahd University of Petroleum and MineralsP. O. Box 5087 Dhahran 31261 Saudi Arabia

Lie symmetry method is applied to analyze a nonlinear elastic wave equation for longitudinal deformations with third-order anharmonic corrections to the elastic energy. Symmetry algebra is found and reductions to second-order ordinary differential equations （ODEs） are obtained through invariance under different symmetries. The reduced ODEs are further analyzed to obtain several exact solutions in an explicit form. It was observed in the literature that anharmonic corrections generally lead to solutions with time-dependent singularities in finite times singularities, we also obtain solutions which Along with solutions with time-dependent do not exhibit time-dependent singularities.

关键词： group invariant solutions Lie symmetries nonlinear elasticity equations partial differential equations

Phase Diagram Body-Centredof Catalytic Oxidation of CO on the Surface-Subsurface of a Body-Centred Cubic Structure with Eley-Rideal Process： A Monte Carlo Simulation

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Chinese Physics Letters 2004年第9期21卷 1838-1841页

作者： AU.Qaisrani M.khalid MusaKaleemBalocht DepartmentofPhysics GomalUniversityD.I.KhanPakistan DepartmentofChemistry GomalUniversityD.I.KhanPakistan

Monte Carlo simulation is used to explore the effects of the Eley-Rideal (ER) process on the phase diagram of the Langmuir–Hinshelwood (LH) type monomer–dimer (CO–O2) catalytic reaction on the surface and subsurface of a body-centred cubic structure, which extends to only two layers in the z-direction. The dimer (O2) is adsorbed in such a way that it takes one surface site whereas the second site is from the subsurface. For this mechanism, an interesting situation develops. The production rate of CO2 is found to be consistent with experiment. The qualitative trend of the surface oxygen coverage is not consistent with the experimental situation in one model while it is found to be consistent with that in another model, i.e. the coverage of surface oxygen decreases slowly with increase of concentration of CO (yCO). Moreover, the production of CO2 can be predicted in the form of a mathematical relation.

关键词： Phase diagrams

Surface Passivation of Ti/4H-SiC Schottky Barrier Diode

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Communications in Theoretical Physics 2012年第10期58卷 577-582页

作者： Muhammad khalid Saira Riaz Shahzad Naseem Microelectronics Division/Centre of Excellence in Solid State Physics School of Physical SciencesUniversity of the Punjab

Surface properties of SiC power devices mostly depend on the passivation layer(PL).This layer has direct influence on electrical characteristics of devices.2D numerical simulation of forward and reverse characteristics with and without different(PLs)(SiO2,HfO2 and Si3N4) has been *** results show that the breakdown voltage increases with increasing PL thickness,and there is a lesser significant effect on forward *** maximum breakdown voltage with and without SiO2 PL is 1240 V and 276 V,***2 PL has compatibility with SiC surface providing high breakdown voltage,6 and 8% higher than that of HfO2 and Si3N4 *** leakage current is observed which then further decreases on reducing the thickness of ***,variation of forward current with dielectric constant and thickness of PLs was ***,it is suggested that matches of our results with published experimental results indicate that the Sentaurus TCAD simulator is a predictive tool for the SiC Schottky barrier diode simulation.

关键词： Passivation breakdown voltage leakage current electric field on-resistance

TWO DISJOINT AND INFINITE SETS OF SOLUTIONS FOR AN ELLIPTIC EQUATION INVOLVING CRITICAL HARDY-SOBOLEV EXPONENTS

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数学物理学报:B辑英文版 2023年第5期43卷 2061-2074页

作者： khalid BOUABID Rachid ECHARGHAOUI Mohssine EL MANSOUR Department of Mathematics Faculty of SciencesIbn Tofail UniversityKenitraB.P.133Morocco

In this paper,by an approximating argument,we obtain two disjoint and infinite sets of solutions for the following elliptic equation with critical Hardy-Sobolev exponents■whereΩis a smooth bounded domain in RN with 0∈?Ωand all the principle curvatures of?Ωat 0 are negative,a∈C1(Ω,R*+),μ>0,02(q+1)/(q-1).By2*:=2N/(N-2)and 2*(s):(2(N-s))/(N-2)we denote the critical Sobolev exponent and Hardy-Sobolev exponent,respectively.

关键词： Laplacien critical Sobolev-Hardy exponent critical Sobolev exponent infinitely many solutions Pohozaev identity

Effect of deposition parameters on structural and mechanical properties of niobium nitride synthesized by plasma focus device

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Chinese Physics B 2015年第6期24卷 416-424页

作者： Jamil Siddiqui Tousif Hussain Riaz Ahmad Nida khalid Center for Advanced Studies in Physics(CASP) 1-Church RoadGC University Department of Physics Government College University

Effects of deposition angle and axial distance on the structural and mechanical properties of niobium nitride syn- thesized by a dense plasma focus （DPF） system are studied. The x-ray diffraction （XRD） confirms that the deposition parameters affect the growth of multi-phase niobium nitride. Scanning electron microscopy （SEM） shows the granular surface morphology with strong thermally assisted coagulation effects observed at the 5-cm axial distance. The non-porous granular morphology observed at the 9-cm distance along the anode axis is different from those observed at deposition angles of 10° and 20°. Energy dispersive x-ray （EDX） spectroscopy reveals the maximum nitrogen content at the shortest （5 cm） axial position. Atomic force microscopy （AFM） exhibits that the roughness of coated films varies for coatings synthesized at different axial and angular positions, and the Vickers micro-hardness test shows that a maximum hardness value is （08.44 ±0.01） GPa for niobium nitride synthesized at 5-cm axial distance, which is about 500% more than that of a virgin sample.

关键词： DPF device niobium nitride XRD SEM AFM micro-hardness

Bendable tube-shaped supercapacitor based on reduced graphene oxide and Prussian blue coated carbon fiber yarns for energy storage

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Journal of Energy Chemistry 2018年第3期27卷 866-873页

作者： Mohd.khalid Ana M.B.Honorato Department of Macromolecular Science and Engineering Case Western Reserve University

Carbon fiber yarns（CFY） are promising as a new type of flexible building blocks for the construction of flexible architectures for the energy storage applications. The main hurdle with CFY is how to make them high energy and power capable by using economically and environmentally viable materials. Here,we report reduced graphene oxide（r GO） and Prussian blue（PB） coated CFY, derived from a facile electrochemical process at room temperature for supercapacitor electrodes. The PB coated CFY and r GO coated CFY electrodes exhibit the excellent gravimetric capacitance of 339 F/g and 160.2 F/g, respectively, in aqueous KCl electrolyte in three-electrode cell configuration. When we coupled these electrodes inside the flexible plastic tube and separated by the electrolyte wet filter paper in order to construct flexible architecture, the resulting device delivers excellent specific energy of 52.1 Wh/kg and 26.5 Wh/kg with offering specific power of 3100 W/kg and 14400 W/kg respectively, under a wide operating potential of1.8 V with excellent rate capability. The device shows high tolerance towards bending, and retained its efficiency to the capacitance after being bent at an angle of 360° for 200 bending cycles.

关键词： Carbon fiber yarns Bendable supercapacitor Energy density Power density

Effect of Phosphorus and Irrigation Levels on Yield,Water Productivity,Phosphorus Use Efficiency and Income of Lowland Rice in Northwest Pakistan

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Rice science 2013年第1期20卷 61-72页

作者： khalid USMAN Department of Agronomy Faculty of AgricultureGomal UniversityDera Ismail Khan 29050Pakistan

With decreasing availability of water for agriculture and increasing demand for rice production, an optimum use of irrigation water and phosphorus may guarantee sustainable rice production. Field experiments were conducted in 2003 and 2004 to investigate the effect of phosphorus and irrigation levels on yield, water productivity （WP）, phosphorus use efficiency （PUE） and income of low land rice. The experiment was laid out in randomized complete block design with split plot arrangements replicated four times. Main plot consisted of five phosphorus levels, viz. 0 （P0）, 50 （P50）, 100 （P100）, 150 （P15o）, and 200 （P200） kg/hm2, while subplots contained of irrigation times, i.e. 8 （I8）, 10 （I10）, 12 （I12）, and 14 （I14） irrigation levels, each with a water depth of 7.5 cm. Mean values revealed that P150 in combination with I10 produced the highest paddy yield （9.8 t/hm2） and net benefit （1 231.8 US$/hm2） among all the treatments. Phosphorus enhanced WP when applied in appropriate combination with irrigation level. The highest mean WP [13.3 kg/（hm2-mm）] could be achieved at Plso with 18 and decreased with increase in irrigation level, while the highest mean PUE （20.1 kg/kg） could be achieved at P100 with I10 and diminished with higher P levels. The overall results indicate that P150 along with I10 was the best combination for sustainable rice cultivation in silty clay soil.

关键词： virrigation level phosphorus phosphorus use efficiency rice water productivity yield

Assessment of seismic hazard of roller compacted concrete dam site in Gilgit-Baltistan of northern Pakistan

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Earthquake Engineering and Engineering Vibration 2021年第3期20卷 621-630页

作者： Shahzada Khurram Perveiz khalid Jahanzeb Qureshi Zia Ud Din Institute of Geology University of the PunjabLahore 54590Pakistan Department of Space Science University of the PunjabLahore 54590Pakistan

The proposed site of the Diamer Bhasha Dam in northern Pakistan is situated in an active tectonic zone with intensive seismicity,which makes it necessary for seismic hazard analysis(SHA).Deterministic and probabilistic approaches have been used for SHA of the dam *** Main Mantle Thrust(MMT),Main Karakaram Thrust(MKT),Raikot-Sassi Fault(RKSF)and Kohistan Fault(KF)have been considered as major seismic sources,all of which can create maximum ground shaking with maximum potential earthquake(MPE).Deterministically estimated MPE for magnitudes of 7.8,7.7,7.6,and 7.1 can be produced from MMT,MKT,RKSF and KF,*** corresponding peak ground accelerations(PGA)of 0.07,0.11,0.13 and 0.05 g can also be generated from these earthquakes,*** deterministic analysis predicts a so-called floating earthquake as a MPE of magnitude=7.1 as close as 10 km away from the *** corresponding PGA was computed as 0.38 g for a maximum design earthquake at the project ***,the probabilistic analysis revealed that the PGA with 50%probability of exceedance in 100 years is 0.18 ***,this PGA value related to the operational basis earthquake(OBE)is suggested for the design of this project with shear wave velocity(V_(s30))equal to 760 m/s under dense soil and soft rock conditions.

关键词： seismic hazard analysis peak ground acceleration Gilgat-Biltastan Diamer Bhasha Dam