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101.
Hassan Hassanabadi Won Sang Chung Soroush Zare Hadi Sobhani 《The European Physical Journal C - Particles and Fields》2018,78(1):83
This paper contains a discussion of a relativistic spin-0 system in the presence of a Gödel-type background space-time. The Duffin–Kemmer–Petiau (DKP) equation in the presence of a Gödel-type background space-time is studied in detail. After a derivation of the final form of this equation in the considered framework, free spin-0 particles have been studied. 相似文献
102.
New ordered MAX phase Mo_2 TiAlC_2: Elastic and electronic properties from first-principles 下载免费PDF全文
First-principles computation on the basis of density functional theory(DFT) is executed with the CASTEP code to explore the structural, elastic, and electronic properties along with Debye temperature and theoretical Vickers' hardness of newly discovered ordered MAX phase carbide Mo_2TiAlC_2. The computed structural parameters are very reasonable compared with the experimental results. The mechanical stability is verified by using the computed elastic constants. The brittleness of the compound is indicated by both the Poisson's and Pugh's ratios. The new MAX phase is capable of resisting the pressure and tension and also has the clear directional bonding between atoms. The compound shows significant elastic anisotropy. The Debye temperature estimated from elastic moduli(B, G) is found to be 413.6 K. The electronic structure indicates that the bonding nature of Mo_2TiAlC_2 is a mixture of covalent and metallic with few ionic characters. The electron charge density map shows a strong directional Mo–C–Mo covalent bonding associated with a relatively weak Ti–C bond.The calculated Fermi surface is due to the low-dispersive Mo 4d-like bands, which makes the compound a conductive one.The hardness of the compound is also evaluated and a high value of 9.01 GPa is an indication of its strong covalent bonding. 相似文献
103.
Rashba effect in presence of a time-dependent interaction has been considered.Then time-evolution of such a system has been studied by using Lewis–Riesenfeld dynamical invariant and unitary transformation method.So appropriate dynamical invariant and unitary transformation according the considered system have been constructed as well as some special cases have come into this article which are common in physics. 相似文献
104.
Hadi Beitollahi Alireza Mohadesi Mortaza Mostafavi Hassan Karimi-Maleh Mehdi Baghayeri Ali Akbari 《Ionics》2014,20(5):729-737
A novel carbon paste electrode modified with carbon nanotubes and 5-amino-2′-ethyl -biphenyl-2-ol was fabricated. The electrochemical study of the modified electrode, as well as its efficiency for electrocatalytic oxidation of ascorbic acid (AA), is described. The electrode was employed to study the electrocatalytic oxidation of AA, using cyclic voltammetry, chronoamperometry, and square-wave voltammetry (SWV) as diagnostic techniques. It has been found that the oxidation of AA at the surface of modified electrode occurs at a potential of about 250 mV less positive than that of an unmodified carbon paste electrode. SWV exhibits a linear dynamic range from 2.0?×?10?7 to 5.0?×?10?4 M and a detection limit of 1.0?×?10?7 M for AA. In addition, this modified electrode was used for simultaneous determination of AA, acetaminophen (AC), and tryptophan (TRP). Finally, the modified electrode was used for determination of AA, AC, and TRP in pharmaceutical products. 相似文献
105.
Abdollahi A Hassani A Ghosta Y Bernousi I Meshkatalsadat MH Shabani R Ziaee SM 《Natural product research》2012,26(1):77-83
The effects of postharvest spraying of essential oils from sweet basil (Ocimum basilicum), fennel (Foeniculum vulgare), summer savory (Satureja hortensis) and thyme (Thymus vulgaris) on fungal decay and quality parameters of the 'Thompson seedless' table grape stored at 0?±?1°C for 60 days were evaluated. Results showed that the essential oils, especially of thyme and fennel, have a good inhibitory effect on the development of fungal decay in Thompson table grapes. In addition, essential oils reduced weight loss, berry and rachis browning and had no considerable adverse effect on the flavour of the fruits. GC-MS analysis showed that the main compounds identified in sweet basil, fennel, summer savory and thyme oils are linalool (65.25%), trans-anethole (64.72%), carvacrol (54.14%) and β-ocimene (12.62%), respectively. Therefore, these essential oils have good potential for use as an alternative to synthetic fungicides for the preservation and storage of table grapes. 相似文献
106.
In this study, the application of various concentrations (0.02%, 0.04%, 0.06% and 0.08%) of Satureja khuzestanica essential oil (EO) was examined on the oxidative stability of sunflower oil and compared to butylated hydroxyanisole (BHA) during storage at 60°C. Gas chromatography (GC) and GC-mass spectrometry analyses of the oils revealed that carvacrol (87.7%) was the major component of EO. Peroxide value and anisidine value measurements in sunflower oil showed that all concentrations of EO had antioxidant effects in comparison to BHA. Oil samples supplemented with EO concentration of 0.08% were the most stable during storage (p?0.05). EO also was able to reduce the stable free radical 2, 2-diphenyl-1-picrylhydrazyl with a 50% inhibition concentration (IC??) of 31.5?±?0.6?μg?mL?1. Therefore, the results indicate that EO could be used as a natural antioxidant in food lipids. 相似文献
107.
Ali Taherkhani Hassan Karimi-Maleh Ali A.Ensafi Hadi Beitollahi Ahmad Hosseini Mohammad A.Khalilzadeh Hassan Bagheri 《中国化学快报》2012,23(2):237-240
A carbon paste electrode(CPE) chemically modified with multiwall carbon nanotubes and ferrocene(FC) was used as a selective electrochemical sensor for the simultaneous determination of trace amounts of cysteamine(CA) and folic acid(FA).This modified electrode showed very efficient electrocatalytic activity for the anodic oxidation of CA.The peak current of differential pulse voltammograms of CA and FA increased linearly with their concentration in the ranges of 0.7-200μmol/L CA and 5.0- 700μmol/L FA.The detection limits for CA and FA were 0.3μmol/L and 2.0μmoI/L,respectively.The diffusion coefficient(D) and transfer coefficient(α) of CA were also determined.These conditions are sufficient to allow determination of CA and FA both individually and simultaneously. 相似文献
108.
Hamid Golchoubian Zahra Mohseni Afshar Golasa Moayyedi Giuseppe Bruno Hadi Amiri Rudbari 《中国化学》2012,30(8):1873-1880
The syntheses of three mixed ligand chelate copper(II) complexes of the type [Cu(L)(acac)(H2O)]BPh4 where acac=acetyleacetonate; L=N,N‐dimethyl,N′‐benzylethane‐1,2‐diamine ( L1 ), N,N‐dimethyl, N′‐2‐methylbenzylethane‐1,2‐diamine ( L2 ) or N,N‐dimethyl,N′‐2‐chlorobenzylethane‐1,2‐diamine ( L3 ) are reported and characterized by elemental analyses, spectroscopic and molar conductance measurements. The X‐ray structure of complex 1 shows that the central copper atom is placed in a distorted square pyramidal geometry made by acac and diamine chelate in the base and a H2O molecule on the apex. The prepared complexes are fairly soluble in a large number of organic solvents and show positive solvatochromism. Calculations of SMLR (stepwise multiple linear regression) method was utilized to find the best model explaining the observed solvatochromic behavior and showed that among different solvent parameters, donor number (DN) is a dominant factor responsible for the shift in the d‐d absorption band of the complexes to the lower wavenumber with increasing its values. The importance of substituent effect in diamine ligand on the spectral and SMLR measurements is also discussed. 相似文献
109.
Hadi Beitollahi Jahan-Bakhsh Raoof Hassan Karimi-Maleh Rahman Hosseinzadeh 《Journal of Solid State Electrochemistry》2012,16(4):1701-1707
This paper reports the selective determination of isoproterenol (IP) in the presence of uric acid (UA) and folic acid (FA)
using 2,7-bis(ferrocenyl ethyl)fluoren-9-one modified carbon nanotube paste electrode (2,7-BFCNPE) in 0.1 M phosphate buffer
solution (PBS) (pH 7.0). The bare carbon paste electrode does not separate the voltammetric signals of IP, UA, and FA. However,
2,7-BFCNPE not only resolved the voltammetric signals of IP, UA, and FA with potential differences of 150, 325, and 475 mV
between IP–UA, UA–FA, and IP–FA, respectively, but also dramatically enhanced the oxidation peak currents of them when compared
to bare carbon paste electrode. In PBS of pH 7.0, the oxidation current increased linearly with two concentration intervals
of IP, one is 0.08 to 17.5 μM and the other is 17.50 to 700.0 μM. The detection limit (3σ) obtained by DPV was 26.0 ± 2 nM. The practical application of the modified electrode was demonstrated by determining IP
in IP injection, urine, and human blood serum. 相似文献
110.
Effects of substrate on crystallinity, surface morphology, and luminescence properties of radio frequency sputtered zinc oxide (ZnO) thin films were investigated. A variety of materials such as Si (100), Si (111), Al2O3, quartz, and silicon carbide (SiC) wafers were examined as substrates for deposition of ZnO thin films. The results showed smooth and uniform growth of c-axis orientation films. The thickness of the layers was about 50 nm. The average grain sizes of films were about 10, 13, and 12 nm for Si (111), quartz, and SiC samples, respectively. The deposited film on Al2O3 showed the largest grain size, about 500 nm. Grazing incidence x-ray diffraction patterns of the samples revealed that sputtered layers on Al2O3 and quartz had better crystallinity with higher peak at (002) orientation compared to Si and SiC substrates. Moreover, the Al2O3 sample exhibited a weak peak at position of (100) planes of ZnO too. The photoluminescence spectra of the samples showed a typical luminescence behavior with a broad UV band, including a main peak at around 388 nm and a weak shoulder peak at around 381 nm, corresponding with bound excitonic recombination and free excitonic recombination, respectively. The luminescence peak revealed that the intensity of UV emission is not necessarily dependent on the grain sizes and the micro-structural quality of ZnO films. 相似文献