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101.
102.
Arham S. Ahmed Ameer Azam M. Chaman S. Tabassum 《Journal of Physics and Chemistry of Solids》2012,73(7):943-947
Nanocrystalline tin oxide (SnO2) powders were synthesized through wet chemical route using tin metal as precursor. The morphology and optical properties, as well as the effect of sintering on the structural attributes of SnO2 particles were analyzed using Transmission electron microscopy (TEM), UV–visible spectrophotometry (UV–vis) and X-ray diffraction (XRD), respectively. The data revealed that the lattice strain plays a significant role in determining the structural properties of sintered nanoparticles. The particle size was found to be 5.8 nm, 19.1 nm and 21.7 nm for samples sintered at 300 °C, 500 °C, and 700 °C, respectively. Also, the band gaps were substantially reduced from 4.1 eV to 3.8 eV with increasing sintering temperatures. The results elucidated that the structural and optical properties of the SnO2 nanoparticles can be easily modulated by altering sintering temperature during de novo synthesis. 相似文献
103.
Mercury selenide (HgSe) nanostructures were synthesized via a sonochemical method based on the reaction between HgCl(2), SeCl(4) and hydrazine hydrate (N(2)H(4)·H(2)O) in water, in presence of various capping agents. The effects of preparation parameters such as: the kind of capping agent and its amount, ultrasonic power, reaction time and temperature were investigated. It was found that morphology, particle size and phase of the products could be greatly affected by these parameters. HgSe nanostructures were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), photoluminescence spectroscopy (PL) and X-ray energy dispersive spectroscopy (EDS). 相似文献
104.
Ali Akbar Ashkarran Azam Iraji?zad Seyed Mohammad Mahdavi Mohammad Mahdi Ahadian Mohammad Reza Hormozi?Nezhad 《Applied Physics A: Materials Science & Processing》2009,96(2):423-428
The microstructural (XRD and SEM) and dielectric behavior of Pb(Zr0.54Ti0.46)O3 (PZT 54/46) ceramic system with donor (La, Nb and La+Nb) doping was studied. For all Nb-doped PZT samples, only one (tetragonal) phase was found, which confirms the compositional
shifts near the morphotropic phase boundary. For La- and La+Nb-doped samples, there are two (rhombohedral and tetragonal)
phases. Dielectric characteristic behavior (1/ε) for La- and La+Nb-doped PZT was associated with two-phase transitions: Ferro–Ferro at low temperature and Ferro–Para at Curie temperature.
For Nb-doped samples, only one phase transition is observed, which indicates the presence of a single ferroelectric phase. 相似文献
105.
S. A. Mardan I. Noureen M. Azam M. A. Rehman M. Hussan 《The European Physical Journal C - Particles and Fields》2018,78(6):516
In this paper, we investigate the gravitational behavior of compact objects with the help of generalized polytropic equation of state in isotropic coordinates. We found three exact solutions of Einstein field equations by taking into account the different values of polytropic index with spherically symmetric anisotropic inner fluid distribution. We have regained the masses of PSR \(\hbox {J}1614-2230\), Vela X-1, Vela 4U, PSR J1903+327 and 4U 1820-30. Speed of sound has been used to analyze the stability of models. The comprehensive analysis indicates that all the models are physically viable and well behaved. 相似文献
106.
Saeedeh Golharani Sajad Jahanbakht Azam Moeini-Nashalji 《Waves in Random and Complex Media》2018,28(3):488-507
In this paper, a plasma waveguide made of two eccentric cylindrical metallic walls have been studied according to the theory of transmission lines. The inductance per unit length L, the capacitance per unit length C, the resistance per unit length R and the shunt conductance per unit length G are obtained. The graphs of variations of the mentioned parameters vs. geometrical dimensions of waveguide are investigated. This investigations have been done for two different types of plasma waveguide. At first stage, plasma region will be considered in cold and collisional approximation and in second stage, a drift plasma in cold collisionless approximation will be considered. Also, graphs of phase velocity variation vs. the main parameters of the waveguide are presented. 相似文献
107.
In this paper,we investigate the stability of quark stars with four different types of inner matter configurations;isotropic,charged isotropic,anisotropic and charged anisotropic by using the concept of cracking.For this purpose,we have applied local density perturbations technique to the hydrostatic equilibrium equation as well as on physical parameters involved in the model.We conclude that quark stars become potentially unstable when inner matter configuration is changed and electromagnetic field is applied. 相似文献
108.
Mehdi Ranjbar Azam Iraji zad Seyyed Mohammad Mahdavi 《Applied Physics A: Materials Science & Processing》2008,92(3):627-634
In this study WO
x
films were deposited by laser ablation of ultra-pure (5N) tungsten trioxide targets onto SiO2 or silicon substrates at 250°C temperature, 100 mTorr oxygen partial pressure and 1×10−5 Torr vacuum. Surface chemical states and compositions of the deposits were determined by X-ray photoelectron spectroscopy.
The results showed that deposits in oxygen partial pressure contain W6+ with x∼3.1, while vacuum-deposited films have different W states with various percentage distributions as W4+>W5+>W6+>W0, and x∼1. We used fast electrical resistance measurement as a probe to study the deposition process. Film resistance as a function
of deposition time in vacuum revealed some microsecond fluctuations modulated on the time variation curve of electrical resistance.
We attribute these data to surface absorption and desorption of oxygen during layer deposition. Finally, the effect of the
laser beam on the target’s structure, surface morphology and chemical state was studied. Our results revealed that in spite
of structural variation by laser irradiation, the O/W ratio remained about 3. 相似文献
109.
Hassan Wafi Garba Muhammad Sabiu Abdullahi Mohamad Shazwan Shah Jamil Nor Azam Endot 《Molecules (Basel, Switzerland)》2021,26(19)
The reduction of 4-nitrophenol to 4-aminophenol by sodium borohydride was used as a model to test the catalytic activity of copper(II) complexes containing N,O-chelating Schiff base ligands. In this study, a series of copper(II) complexes containing respective Schiff base ligands, N′-salicylidene-2-aminophenol (1), N′-salicylidene-2-aminothiazole (2), and N,N′-bis(salicylidene)-o-phenylenediamine (3), were synthesized and characterized by elemental analysis, Fourier transform infrared (FT-IR), UV-Visible (UV-Vis) and electron paramagnetic resonance (EPR) spectroscopies. The results from the 4-nitrophenol reduction showed that 3 has the highest catalytic activities with 97.5% conversion, followed by 2 and 1 with 95.2% and 90.8% conversions, respectively. The optimization of the catalyst amount revealed that 1.0 mol% of the catalyst was the most optimized amount with the highest conversion compared to the other doses, 0.5 mol% and 1.5 mol%. Recyclability and reproducibility tests confirmed that all three complexes were active, efficient, and possess excellent reproducibility with consistent catalytic performances and could be used again without a major decrease in the catalytic activity. 相似文献
110.
This paper is a report on the development of a convenient approach to fabricating a very efficient hybrid photoelectrocatalyst for water splitting.This photoele... 相似文献