Cogent Physics最新文献_第4页

First principles investigation of structural, elastic, electronic and optical properties of ABi2O6 (A = Mg, Zn) with trirutile-type structure 三重结构ABi2O6 (A = Mg, Zn)的结构、弹性、电子和光学性质的第一性原理研究

Cogent Physics Pub Date : 2016-12-01 DOI: 10.1080/23311940.2016.1257414

M. A. Rahman, M. A. Rahman, U. Chowdhury, M. Bhuiyan, Md. Lokman Ali, M. R. Sarker

{"title":"First principles investigation of structural, elastic, electronic and optical properties of ABi2O6 (A = Mg, Zn) with trirutile-type structure","authors":"M. A. Rahman, M. A. Rahman, U. Chowdhury, M. Bhuiyan, Md. Lokman Ali, M. R. Sarker","doi":"10.1080/23311940.2016.1257414","DOIUrl":"https://doi.org/10.1080/23311940.2016.1257414","url":null,"abstract":"Abstract First principles calculations based on density functional theory with generalized gradient approximation are performed to investigate the structural, elastic, electronic, and optical properties of new bismuth oxides, ABi2O6 (A = Mg, Zn) with the trirutile-type structure. Initially, the geometry structures obtained by geometry optimization are consistent with the experimental values. The calculated structural parameters show a good agreement with the experimental results. The optimized lattice parameters, six independent elastic constants (C11, C12, C13, C33, C44 and C66), bulk modulus (B), shear modulus (G), Young’s modulus (Y), Pugh’s ratio (G/B), Poisson’s ratio (ν), and elastic anisotropy (A) are calculated and discussed. This is the first quantitative theoretical prediction of the electronic, elastic, and optical properties of these compounds. The investigation of the electronic band structures reveals that these compounds are electrical conductors, with contribution predominantly from the Bi 6p states. The analysis of the elastic constants and other moduli shows large anisotropy on elasticity and brittle behavior. The origins of features that appear in different optical properties of these two compounds have been discussed using band structures. The large reflectivity of the predicted compounds in the low energy region might be helpful in high-quality candidate materials for coating to avoid solar heating.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1257414","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60084752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Forecasting of the electricity price on the day-ahead electricity market in Russia 俄罗斯电力市场日前电价预测

Cogent Physics Pub Date : 2016-11-03 DOI: 10.2139/ssrn.2877697

A. Maksimov, Daria V. Shchurupova

引用次数: 3

Preparation and thermal properties of Sm2AlTaO7 sm2alta7的制备及其热性能

Cogent Physics Pub Date : 2016-10-28 DOI: 10.1080/23311940.2016.1244244

Yu Haipeng, Chen Xiaoge, Zhang Hongsong, Zhang Haoming, Zhao Yongde, Liu Yanxu, Tang An

引用次数: 5

CLÆSS: The hard X-ray absorption beamline of the ALBA CELLS synchrotron CLÆSS: ALBA CELLS同步加速器的硬x射线吸收束线

Cogent Physics Pub Date : 2016-10-04 DOI: 10.1080/23311940.2016.1231987

L. Simonelli, C. Marini, W. Olszewski, M. Á. Pérez, N. Ramanan, G. Guilera, V. Cuartero, K. Klementiev

引用次数: 103

Influence of oriented magnetic field on natural convection in an equilateral triangular enclosure filled with water- and kerosene-based ferrofluids using a two-component nonhomogeneous thermal equilibrium model 基于双分量非均匀热平衡模型的定向磁场对充满水基和煤油基铁磁流体的等边三角形圈闭内自然对流的影响

Cogent Physics Pub Date : 2016-09-29 DOI: 10.1080/23311940.2016.1234662

M. Rahman

{"title":"Influence of oriented magnetic field on natural convection in an equilateral triangular enclosure filled with water- and kerosene-based ferrofluids using a two-component nonhomogeneous thermal equilibrium model","authors":"M. Rahman","doi":"10.1080/23311940.2016.1234662","DOIUrl":"https://doi.org/10.1080/23311940.2016.1234662","url":null,"abstract":"Abstract In this paper, hydromagnetic natural convection heat transfer in an equilateral triangular enclosure filled with water- and kerosene-based ferrofluids has been analyzed using a two-component non-homogeneous thermal equilibrium model. The enclosure is permeated by an inclined magnetic field of having uniform strength. The effects of Brownian motion and thermophoresis of the nanoparticles are incorporated into the ferrofluid model. The Galerkin weighted residual finite-element method has been employed to solve the governing nondimensional partial differential equations. Fe3O4-water and Co-kerosene ferrofluids have been used for the present investigation. The effects of various model parameters such as Rayleigh number, Hartmann number, and inclination angle of the magnetic field on the streamlines, isotherms, and isoconcentrations have been displayed graphically. In addition, the heat transfer augmentation for various combinations of model parameters have been done in light of the average Nusselt number from the bottom heated wall. The results indicate that increment in the magnetic field reduces the heat transfer rate, whereas increment in the magnetic field inclination angle augments the heat transfer rate significantly. The results further indicate that there exists a strong interaction between cobalt and kerosene in the presence of magnetic field which can be utilized efficiently for desired heat transfer augmentation in engineering problems.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1234662","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60085134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Ab initio study on structural, elastic, electronic and optical properties of cuprate based superconductor 铜基超导体结构、弹性、电子和光学性质的从头算研究

Cogent Physics Pub Date : 2016-09-28 DOI: 10.1080/23311940.2016.1231361

U. Chowdhury, Md Atikur Rahman, M. A. Rahman, M. Bhuiyan, Md. Lokman Ali

{"title":"Ab initio study on structural, elastic, electronic and optical properties of cuprate based superconductor","authors":"U. Chowdhury, Md Atikur Rahman, M. A. Rahman, M. Bhuiyan, Md. Lokman Ali","doi":"10.1080/23311940.2016.1231361","DOIUrl":"https://doi.org/10.1080/23311940.2016.1231361","url":null,"abstract":"Abstract The structural, elastic, electronic, and optical properties of BaCuO2 are investigated using the plane-wave ultrasoft pseudo-potential technique, which is based on the first-principle density functional theory (DFT) with generalized gradient approximation (GGA). The calculated structural parameters show a good agreement with the experimental and other theoretical results. The optimized lattice parameters, independent elastic constants (C11, C12, C13, C33, C44, and C66), Bulk modulus B, compressibility K, Shear modulus G, and Poisson’s ratio ν, as well as the band structures, total and atom-projected densities of states and finally the optical properties of BaCuO2 has been evaluated and discussed. The band structure and density of states show that these phases have metallic behavior and the major contribution comes from O-2P states for BaCuO2. Further, the first time investigated optical functions reveal that the reflectivity is high in the IR-UV region up to 28.5eV for BaCuO2 respectively, showing this to be a promising coating material.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-09-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1231361","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60085095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Structural, magnetic and dielectric properties of pure and nickel-doped barium nanohexaferrites synthesized using chemical co-precipitation technique 化学共沉淀法合成纯和掺镍钡纳米六铁氧体的结构、磁性和介电性能

Cogent Physics Pub Date : 2016-07-18 DOI: 10.1080/23311940.2016.1208450

Naini Dawar, Mansi Chitkara, I. S. Sandhu, J. Jolly, S. Malhotra

{"title":"Structural, magnetic and dielectric properties of pure and nickel-doped barium nanohexaferrites synthesized using chemical co-precipitation technique","authors":"Naini Dawar, Mansi Chitkara, I. S. Sandhu, J. Jolly, S. Malhotra","doi":"10.1080/23311940.2016.1208450","DOIUrl":"https://doi.org/10.1080/23311940.2016.1208450","url":null,"abstract":"Abstract Nickel-doped barium nanohexaferrites with the chemical formula BaNixFe(12-x)O19 are prepared using the chemical co-precipitation technique. The calcination of the samples is done at 800°C for 4 h. In order to carry out the structural analysis that includes the crystallographic and the morphological investigations, X-ray diffraction and TEM are carried out to govern the phase, structure and the size of the crystal. By the use of Debye–Scherrer equation, the size of the crystallite is calculated to be in the range of 38–100 nm. TEM results reveal the magnetoplumbite structure of the hexaferrites. The M–H curve obtained using the Vibrating Sample Magnetometer computes the magnetic parameters like saturation magnetization, coercivity, remanence and verifies the behaviour of hexaferrites as hard magnetic materials. Further, the effect of variation in calcination temperature is also investigated on the values of magnetic parameters of hexaferrites. In order to carry out the investigations on the electrical properties of hexaferrites, the two-probe method and parallel plate capacitor set-up are used. The values of relative permittivity, dielectric loss and loss tangent are computed as a function of frequency. The values of DC electrical resistance for pure and nickel-doped barium nanohexaferrites are evaluated from the slope of I–V graphs.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1208450","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60085081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

A novel synthesis of polymeric CO via useful hard X-ray photochemistry 用硬x射线光化学合成聚合一氧化碳的新方法

Cogent Physics Pub Date : 2016-04-25 DOI: 10.1080/23311940.2016.1169880

M. Pravica, D. Sneed, Quinlan B. Smith, B. Billinghurst, T. May, M. White, K. Dziubek

{"title":"A novel synthesis of polymeric CO via useful hard X-ray photochemistry","authors":"M. Pravica, D. Sneed, Quinlan B. Smith, B. Billinghurst, T. May, M. White, K. Dziubek","doi":"10.1080/23311940.2016.1169880","DOIUrl":"https://doi.org/10.1080/23311940.2016.1169880","url":null,"abstract":"Abstract We report on the synchrotron hard X-ray-induced decomposition of strontium oxalate (SrC2O4) pressurized to 7 GPa inside a diamond anvil cell (DAC). After some 4 h of irradiation in a white X-ray synchrotron beam, a dark reddish/brown region formed in the area of irradiation which was surrounded by a yellowish brown remainder in the rest of the sample. Upon depressurization of the sample to ambient conditions, the reacted/decomposed sample was recoverable as a dark brown/red and yellow waxy solid. Synchrotron infrared spectroscopy confirmed the strong presence of CO2 even under ambient conditions with the sample exposed to air and other strongly absorbing regions, suggesting that the sample may likely be polymerized CO (in part) with dispersed CO2 and SrO trapped within the polymer. These results will have significant implications in the ability to readily produce and trap CO2 in situ via irradiation of a simple powder for useful hard X-ray photochemistry and in the ability to easily manufacture polymeric CO (via loading of powders in a DAC or high volume press) without the need for the dangerous and complex loading of toxic CO. A novel means of X-ray-induced polymerization under extreme conditions has also been demonstrated.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1169880","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60085048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Phononic band gap and wave propagation on polyvinylidene fluoride-based acoustic metamaterials 聚偏氟乙烯基声学超材料的声子带隙和波传播

Cogent Physics Pub Date : 2016-04-11 DOI: 10.1080/23311940.2016.1169570

O. Oltulu, Sevket Simsek, A. Mamedov, E. Ozbay

{"title":"Phononic band gap and wave propagation on polyvinylidene fluoride-based acoustic metamaterials","authors":"O. Oltulu, Sevket Simsek, A. Mamedov, E. Ozbay","doi":"10.1080/23311940.2016.1169570","DOIUrl":"https://doi.org/10.1080/23311940.2016.1169570","url":null,"abstract":"Abstract In the present work, the acoustic band structure of a two-dimensional phononic crystal (PC) containing an organic ferroelectric (PVDF-polyvinylidene fluoride) and topological insulator (SnTe) was investigated by the plane-wave-expansion (PWE) method. Two-dimensional PC with square lattices composed of SnTe cylindrical rods embedded in the PVDF matrix is studied to find the allowed and stop bands for the waves of certain energy. Phononic band diagram ω = ω(k) for a 2D PC, in which non-dimensional frequencies ωa/2πc (c-velocity of wave) were plotted vs. the wavevector k along the Г–X–M–Г path in the square Brillouin zone shows five stop bands in the frequency range between 10 and 110 kHz. The ferroelectric properties of PVDF and the unusual properties of SnTe as a topological material give us the ability to control the wave propagation through the PC over a wide frequency range of 103–106 Hz. SnTe is a discrete component that allows conducting electricity on its surface but shows insulator properties through its bulk volume. Tin telluride is considered as an acoustic topological insulator as the extension of topological insulators into the field of “topological phononics”.","PeriodicalId":43050,"journal":{"name":"Cogent Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23311940.2016.1169570","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60085036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Effect of ultra-high pressure on small animals, tardigrades and Artemia 超高压对小动物、缓步动物和蒿属植物的影响

Cogent Physics Pub Date : 2016-04-06 DOI: 10.1080/23311940.2016.1167575

F. Ono, Y. Mori, K. Takarabe, Akiko Fujii, M. Saigusa, Y. Matsushima, D. Yamazaki, E. Ito, S. Galas, N. Saini

引用次数: 19