Karim, Hawbash H.Omar, M. S.Qader, Ibrahim Nazem
10页查看更多>>摘要：The Morelli-Callaway model was used to calculate the lattice thermal conductivity (LTC) of indium arsenide in both zinc blende and wurtzite phases of bulk and nanowire (NW) forms under applied hydrostatic pressures. Calculations were performed for NWs with diameters of 50, 63, 66, 100, and 148 nm in the temperature range of (0-400) K. The melting temperature and hydrostatic pressure phase diagram of the bulk and NW forms were predicted using the Clapeyron equation. A new method was developed to examine various related parameters, such as bulk modulus and mass density. The influence of pressure on melting temperature, melting enthalpy, melting entropy, surface energy, and stress. Results indicate that the calculated values of group velocity increased with the increase in NW size. The melting temperature dropped sharply with the rise in pressure. The pressure and temperature dependencies of the LTC were obtained, and they decreased with applied hydrostatic pressure.
原文链接:
NSTL
Elsevier
Lin, HuilongTong, MuyunWang, HaoLu, Nan...
8页查看更多>>摘要：Metal matrix for the impact protection often requires high strength and good ductility as well as large energy absorption capacity. However, the traditional metal matrix alloys show relatively low strength and ductility to limit the energy absorption capacity. Here, the effect of chemical composition on properties of CoxNi50-xFe25Cr25 high entropy alloys is studied using first-principal calculations. The integrated method considering the competitive relationship between the strength and ductility is proposed to evaluate the energy absorption capacity. The results show that CoNiFeCr HEA with high strength and good ductility exhibits the exceptional energy absorption capacity, where the specific strength and ductility are 889 kN m/kg and 0.99. This work gives a new light into the selection and evaluation of strong energy-absorbing alloys.
原文链接:- NSTL
- Elsevier
Sahoo, Rashmi RekhaChoudhary, R. N. P.
12页查看更多>>摘要：Comprehensive study of structural, dielectric, electrical, and ferroelectric characteristics of Yttrium Barium Copper Oxide (Y2BaCuO5) ceramic, (accompanying phase of high-Tc superconductor YBa2Cu3O7-X can unravel plethora of fascinating applications. Y2BaCuO5 green phase cuprate has been prepared by employing ceramic fabrication technology. Room-temperature X-ray diffraction data of the polycrystalline sample suggests that it crystallizes in orthorhombic system in non-centrosymmetric Pbn2(1) spacegroup. The microstructure and elemental composition clearly illustrated by SEM micrograph and EDAX data. Frequency dependence of dielectric parameter has been discussed using Maxwell-Wagner model. Grain and grain boundary effects discussed using Nyquist plots; fitted to RQC and RC-RQC circuits. Temperature and Frequency dependent conductivity behaviour are explained using Arhenius equation and Jonscher power law. NSPT and CBH model of charge transport mechanisms observed. (I-V) charecteristics demonstrates semiconductor behaviour of Y2BaCuO5 and its suitability for rectifier applications. Existence of hysteresis loop at room and high temperature up to 200 C suggests ferroelectricity in Y2BaCuO5.
原文链接:- NSTL
- Elsevier
Ahmed, HussainMukhtar, SurayyaAgathopoulos, SimeonIlyas, Syed Zafar...
9页查看更多>>摘要：Lead-free perovskite solar cells (PSCs), such as the mixed-halide perovskites (MHPs) ones, are promising devices in order to overcome the inherent problems of instability and toxicity of the lead-based PSCs. This is the first study that reports on Ga-based lead-free mixed halide perovskites with a general formula of Cs3GaI6-xBrx for 0 <= x <= 6, investigated by CASTEP with norm-conserving and Vanderbilt ultrasoft pseudopotentials along the projector augmented wave (PAW) method (for core-level properties) in the framework of density functional theory (DFT). The role of Ga at the B position of the perovskite structure ABX(3) was investigated. The effect of increasing of I concentration was thoroughly determined. The investigated compounds manifest good structural stability and have energy bandgaps close to the Shockley-Queisser limit of 1.34 eV. The bandgaps of Cs3GaI2Br4, Cs3GaI3Br3, Cs3GaI4Br2, and Cs3GaI5Br were calculated as 1.779, 1.615, 1.354, and 1.319 eV, respectively. The optical absorption coefficients of the investigated MHPs lie in the range of 10(4) per cm. Among the investigated materials, Cs3GaI4Br2 and Cs3GaI5Br are recommended for solar cells and other photovoltaic applications.
原文链接:- NSTL
- Elsevier
Kushvaha, D. K.Rout, S. K.Tiwari, B.
15页查看更多>>摘要：The article depicts structural, microstructural, and electrical behavior of Bi-0.5(Na0.8K0.2)(0.5)TiO3-BaNb2O6 (BNKT-BN) composite, synthesized by cost-effective solid-state reaction technique. The article demonstrates a detailed study of phase formation, impedance spectroscopy, ferroelectric, piezoelectric, and high-density energy storage behavior of investigated materials. The grain size distribution shows dense grain with an average grain size of composite within the range of 1.25 mu m-1.42 mu m. The investigation shows that with the addition of orthorhombic BN phase in tetragonal BNKT phase, the piezoelectric strain decreases from 0.0144% for 00BN to 0.0018% for 40BN. With the addition of 10% of BN phase, a sudden and significant drop in dielectric constant could be observed from -3485(00BN) to -1470, which also reduces the relaxor property of material. The 40BN with recoverable energy -136 mJ/cm(3) and -52% efficiency suggests the composition suitable for pulsed power application.
原文链接:- NSTL
- Elsevier
Hosseini, ZakiehAzizian-Kalandaragh, YasharSobhanian, SamadPirgholi-Givi, Gholamreza...
10页查看更多>>摘要：In this paper, we report a simple ultrasound-assisted method for the preparation of CdS nanostructures to utilize as an interfacial layer for fabrication of Al/CdS-PVP/p-Si structure. The comparison of C-f and I-V characterizations on both Al/p-Si (MS) and Al/CdS-PVP/p-Si (MPS) Schottky structures have been analyzed and reported. For the fabrication of CdS semiconductor nanostructures, the sonochemistry method was used. The optical, compositional, and structure of the prepared CdS nanostructures have been investigated by UV-Vis spectroscopy, X-ray diffraction (XRD), FE-SEM, and EDX techniques. The main electrical and dielectric parameters of the fabricated MS and MPS structures have been characterized. The analyses depict the presence of CdS-PVP nanocomposite improves the efficiency of the MPS diode by reducing the ideality factor and increasing the barrier height and shunt resistance. The result of dielectric studies showed dielectric parameters are strongly frequency-dependent.
原文链接:- NSTL
- Elsevier
Aziz, FatimaAbo-Dief, Hala M.Warsi, Al-zohaWarsi, Muhammad Farooq...
14页查看更多>>摘要：A facile strategy of co-precipitation and ultra-sonication was used for the formation of pristine metal oxides (NiO and ZnO) and NiO/ZnO nanocomposite respectively. X-ray Diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used for the structural, spectral and morphological analysis of as synthesized sample. The band gap value of NiO/ZnO nanocomposite was 1.87eV. The crystalline size of the nano-composite calculated using XRD data is 10.88 nm. Photocatalytic ability of as synthesized samples was examined for the degradation of methylene blue, Rhodamine-B and Benzoic acid. The percentage degradation of methylene blue using NiO, ZnO and NiO/ZnO nanocomposite was 54%, 81.5% and 97.1% while in case of Rhodamine-B and Benzoic acid the degradation efficiency of as synthesized samples was 49.6%, 77% and 88.1% for Rhodamine B and 59.2%, 81.3 and 93.2 for Benzoic acid. This enhanced photo catalytic ability of nanocomposite make it a potential candidate for removal of organic pollutants from waste water.
原文链接:- NSTL
- Elsevier
Nazir, RabiaYaqoob, JunaidKhan, Muhammad UsmanGilani, Mazhar Amjad...
15页查看更多>>摘要：Fabrication of stable novel nonlinear optical (NLO) materials is tremendously demanding owing to their ubiquitous optoelectronic applications. For meeting the briskly expanding demands of novel NLO materials, herein we made an attempt to design alkali metals (Li, Na and K) doped 2N-atoms functionalized corannulene (C18N2H10) complexes. Geometric, thermodynamics, electronics and NLO properties of newly designed complexes are explored by using density functional theory (DFT) method. The computational results revealed that doped complexes exhibit excellent thermodynamic stabilities with binding energy of -28.57 kcalmol(-1). The HOMO-LUMO (EH-L) energy gap is narrowed considerably and the smallest EH-L gap is executed 1.01 eV. Time-dependent density functional theory (TD-DFT) calculations demonstrate that these complexes are transparent in the ultra violet (UV) region. Natural bond orbitals (NBOs), total density of state (TDOS) and partial density of state (PDOS) and non-covalent interaction (NCI) analyses are performed to confirm the charge transfer, the participation of different fragments and type of the interaction respectively. The highest first hyperpolarizability of 4.84 x 10(4) au is computed for IV-ex isomer of series Na@2N-Cor. These fascinating results will attract the high research interest of equally theoretical as well as experimental researchers for developing high performance NLO materials.
原文链接:- NSTL
- Elsevier
Abid, MuhammadAyoub, AreedaAkram, Javed
7页查看更多>>摘要：We study the significance of Photon/Phonons bunching and antibunching on the dynamics of the quantum entanglement in the presence of coupled PT-symmetry systems with balanced/unbalanced gain and loss. We suggest a hybrid electromechanical system to realize a strong and tunable coupling between a CoplanarWaveguide (CPW) microwave cavity and a nanomechanical resonator (NAMR) via a superconducting Transmon qubit. The hybrid electromechanical system consists of a non-hermitian Hamiltonian with balanced/unbalanced gain and loss. The interplay between the quantum entanglement and the PT-symmetry systems is also thoroughly investigated. We frame a connection between Number operators, Photon/Phonons antibunching, and entanglement. It has been observed that the relative Photon/Phonons numbers play a key role in the quantum entanglement dynamics. Furthermore, we study that quantum entanglement can be characterized by defining a Photon/Phonons antibunching. The Photon/Phonons antibunching is strongly dependent on the initial squeezed state and the rate of balanced/unbalanced gain and loss of the system.
原文链接:- NSTL
- Elsevier
