Namhongsa, W.Seetawan, T.
5页查看更多>>摘要：A horizontal-shaped cell of a bulk oxide thermoelectric material was constructed using misfit layered Ca3Co4O9 (CCO) and perovskite CaMnO3 (CMO). The electrical power was measured based on the operating parameters. The horizontal shape can improve the efficiency of the thermoelectric cell because it reduces the heat loss through the sidewalls to the junction of the thermoelectric legs, resulting in an improved thermoelectric efficiency. The pair was connected to a series circuit to generate an open-circuit voltage (V-OC) of 107.98 mV. The maximum output power (P-max) of the thermoelectric cell was 7.1 mu W at triangle T = 473 K. A significant increase in the output characteristics of the cell indicates that the bulk was effective. The horizontal-shaped cell of the bulk thermoelectric oxide exhibited promising output characteristics.
原文链接:
NSTL
Elsevier
Ghorbani-Oranj, FarshidAbdi-Ghaleh, RezaRoumi, BitaJamshidi-Ghaleh, Kazem...
9页查看更多>>摘要：In this paper, the transmission, Faraday rotation, and ellipticity spectra of the multilayered structures with the arrangement of the periodic and fifth-order Fibonacci sequence have been numerically studied in the THz frequency region. The building blocks of the structures are a graphene sheet on the SiC layer (G-SiC), and a SiO2 layer. An external magnetic field is perpendicularly applied to the structures to induce the gyrotropic characteristics of the graphene sheets. The graphene sheets are considered as the thickness-less surfaces, and the 4 by 4 transfer matrix method has been utilized to study the mentioned spectra for TM and TE polarizations. The effects of incident angles have been investigated on the responses of the structures. The results revealed that the Fibonacci structure indicates a high Faraday rotation angle at around 11 THz. This property originates from the particular arrangement of the constituting layers of the Fibonacci structure.
原文链接:- NSTL
- Elsevier
Xu, BeiSun, ShoufaGu, Qiang
6页查看更多>>摘要：We investigate the Kondo effect of a spin-3/2 Fermi gas and give a detailed calculation of the impurity resistance and ground state energy based on the s-d exchange model. It is found that the impurity resistance increases logarithmically with the decrease of temperature in the case of antiferromagnetic coupling similar to the spin-1/2 system but has a larger resistance minimum value due to the increase of spin scattering channels. In the case of antiferromagnetic interaction, the ground state is still the Kondo singlet state while the septuplet state has the lowest energy for ferromagnetic coupling. And with the same antiferromagnetic s-d coupling parameter, the energy of the Kondo singlet state is lower than spin-1/2, which indicates that the larger spin, the easier it is to enter the Kondo-screened phase. This provides some theoretical support for the realization of the Kondo effect with ultra-cold atoms.
原文链接:- NSTL
- Elsevier
Irshad, AmnaShahid, MuhammadEl-Bahy, Salah M.El Azab, Islam H....
13页查看更多>>摘要：The breakdown of the coloured and colourless organic dyes under natural sunlight was investigated by the prepared photocatalysts. Cobalt aluminate (CoAl2O4, CA) and nickel doped cobalt aluminate (Ni-CoAl2O4, NCA) were well synthesized by an easy pechini route. Ultra-sonication route was followed to prepare composite with carbon nanotubes (CoAl2O4@CNT, NCA@CNT). The prepared catalysts were comprehensively characterized by various techniques. Spinel structure and functional groups of synthesized photocatalysts was confirmed by XRD and FT-IR techniques. The surface morphology of the synthesized materials was analyzed via SEM. The optical properties of fabricated photocatalysts were investigated via UV-Visible spectroscopy. NCA@CNT nano composite exhibited greater photocatalytic activity than doped and undoped photocatalysts. NCA@CNT exhibited 92.7%, 88.77%, and 63.34% photodegradation of crystal violet, methylene blue, and benzoic acid respectively. A scavenger experiment was carried out to figure out efficient photoactive species taking part in the photodegradation of organic pollutants.
原文链接:- NSTL
- Elsevier
El Mouhi, RahmaSlimi, AhmedFitri, AsmaeBenjelloun, Adil Touimi...
13页查看更多>>摘要：In this study, the electrochemical, photovoltaic and absorption properties of the new designed organic sensitizers dyes: Dye-1, Dye-2, Dye-3 and Dye-4 based on Dye-R, of D-pi-A architecture, before and after binding to the TiO2 cluster surface on the ability to inject electrons to the surface. The D donor is the thieno[2,3-b] indole, pi-spacer is thiophene, A acceptor is cycnoacrylic acid (CA). The properties were calculated using functional density theory (DFT), time-dependent TD-DFT and the density-functional tight-binding (DFTB) approach. Our study also focused on the analysis of the effects of the introduction of the auxiliary donor (D ')/acceptor (A ') groups on the main photovoltaic properties of the reference molecule Dye-R and to study the relationship between the molecular structure and optoelectronic properties. The analysis of the calculated properties of the new designed compounds D-D '-pi-A (Dye-1), D-pi-D '-A (Dye-2), D-A '-pi-A (Dye-3) and D-pi-A '-A (Dye-4), where A ' is benzothiadiazole and D ' is 9,9-diethyl-9H-fluorene, indicate that the molecular architecture has a significant effect on various properties of the studied dyes and that nature (donor D ' or acceptor A ') of the introduced groups, as well as the choice of their locations with respect to the 7E bridge, is of great importance. Indeed, among the four designed compounds Dye-4 (D-pi-A '-A) and Dye-3 (D-A '-pi-A) display significantly better properties than those of the reference molecule Dye-R (D-pi-A) and of the two other designed dyes Dye-1 (D-D '-7E-A), Dye-2 (D-pi-D '-A).
原文链接:- NSTL
- Elsevier
Sihi, AntikPandey, Sudhir K. K.
8页查看更多>>摘要：We present a comparative electronic structure study using DFT and various beyond-DFT (DFT+U, G(0)W0, DFT+DMFT) methods for ferromagnetic Iron (Fe) to find better approach for describing the spectral properties of correlated magnetic system. The computed value of U (W) is~& nbsp;5.4 (~& nbsp;0.8) eV. The calculated spectra of all methods are providing good agreement with experimental spectra (ES) for peaks' positions. But, the proper line shape is only found from DFT+DMFT with correct estimation of incoherent states, which depends on J and form of local Coulomb interactions. The estimation of reduced magnetization as function of reduced temperature using DFT+DMFT shows good agreement with the experimental data. The insight of paramagnetic electronic structure of Fe is also explored. This work suggests that even for simple correlated magnetic metal, we need DFT+DMFT method to reproduce the ES with great accuracy.
原文链接:- NSTL
- Elsevier
Li, LeiGong, YuanyuanWang, ChenZhang, Yujing...
7页查看更多>>摘要：In this paper, we adopt copper-mould casting to prepare the compound with nominal composition of LaFe10-.3Al(2.7), which has been reported to exhibit isotropic zero thermal expansion (ZTE). The rapid cooling rate provided by copper-mould makes the alpha-Fe phases in both as-cast and annealed sheets have similar size and homogeneously distributed. This improvement is helpful to prepare bulks with uniform and stable thermal expansion. On the other hand, the rapid cooling rate reduces the size of the alpha-Fe phases in the as-cast sheet. It facilitates the formation of NaZn13 phase during annealing. For the sheet with thickness = 2 mm, annealing time can be shorten to be 2 days. Moreover, we add Co in the composition to enhance the magnetic ordering disordering temperature of the NaZn13 phase. The ZTE temperature region is successfully enlarged to room temperature. Our results provide a strategy to design LaFe13-xAlx bulks with ZTE reaching room temperature.
原文链接:- NSTL
- Elsevier
Sarkar, JitGanguly, Subhas
7页查看更多>>摘要：Cu-Ag core-shell nanowires are a special type of nanostructured material, which are characterized by excellent oxidation resistance due to the Ag shell, together with very high conductivity and flexibility with the presence of copper nanowires (Cu NWs) in the core. This article reports a theoretical characterization of thermal properties of Cu-Ag core-shell nanowires using a non-equilibrium molecular dynamics simulation study. The important thermal properties include thermal conductivity, melting point, specific heat capacity, and coefficients of thermal expansion have been simulated against the size parameters of the nanowires. The simulation has recognized the notable phenomenon such as lower thermal conductivity as compared to the bulk copper, negative coefficients of thermal expansion and the melting point as high as 1369.8 K. The simulated results and the overall thermal behaviour of the Cu-Ag core-shell nanowires have been discussed in this article with insight into the different phenomenon occurring at the atomic scale.
原文链接:- NSTL
- Elsevier
Zhang, JingZhang, JingziYang, XiaohangWang, Weidong...
5页查看更多>>摘要：To explore comprehensive performance has been the focus of attention utilized advanced technique to prepare different chemical and crystal structures of free-lead dielectric ceramics. In this paper, ferroelectric Ba(Zr0.3Ti0.7) O-3/Ba(Zr0.05Ti0.95)O-3 bilayer thin film has been fabricated on SrTiO3 substrate by pulsed laser deposition technique. X-ray diffraction analysis confirms crystalline nature of the film. The morphology and the ingredient of the film was observed utilizing scanning electron microscope and Energy dispersive spectrometer, respectively. Related electrical measurements, including dielectric and ferroelectric, were recorded for the film. It was found that there are the multi-peaks on dielectric spectrum of the film, which is the discrepancy with Ba(ZrxTi1-x) O-3 target material. It is proposed that the dielectric character of the film is relevance to the intrinsic property of Ba(ZrxTi1-x)O-3 target material and the electric performance of the interface in the film. This work will generate fresh insights into exploring various structure and functional Ba(ZrxTi1-x)O3 material system.
原文链接:- NSTL
- Elsevier
Zhang, TingyuYuan, ZhangfuWang, RongyueMa, Bowen...
8页查看更多>>摘要：The alloy composition influences the wettability of molten metal at high temperatures. A new Sn-Co-La alloy was used as a surface adhesive for NdFeB material and the wettability and contact surface morphology of the alloy on NdFeB substrate were studied. To explain the connectionism of alloy on NdFeB substrate following lanthanum addition, the interfacial reaction activation energy of the Sn-Co-La/NdFeB system was calculated. The results show that when the percent of cobalt in the alloy is grown, its melting point rises, making it harder to wet on the NdFeB surface. The activation energy of the interfacial contact between the alloy and the NdFeB substrate surface is reduced from 168.371 kJ/mol to 107.062 kJ/mol when the Lanthanum concentration is increased from 0.5 wt% to 1 wt%. The inclusion of lanthanum increases the thickness of intermetallic compounds and improves the wettability of the alloy and substrate.
原文链接:- NSTL
- Elsevier
