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Using the Green's function approach, the density–density correlation function and the dielectric function in the random-phase approximation for a quasi-two-dimensional (quasi-2D) dipolar Bose gas are derived. From the pole of the density correlation function, by considering thermally induced roton-like excitations, the excitation spectrum of the system is calculated. It is shown that the position and depth of the roton minimum of the excitation spectrum are tunable by changing the temperature. To show how the position of the roton minimum influences the phenomenon of superfluidity, the superfluid density of the system is obtained and it is shown that the interplay of the thermal rotonization, contact and dipole–dipole interaction (DDI) can affect the superfluid fraction of a quasi-2D Bose gas. It is found that contact, DDI interactions, and thermally induced rotons enhance the fluctuations and reduce the superfluid density. In the absence of DDI and thermally induced rotons, the usual T3 dependence of superfluid density in 2D is obtained and the correction T4 term arises from DDI. It is shown that if the roton minimum is close to zero, the thermally induced rotons change the linear temperature dependence of the superfluid fraction, leading to a transition to nontrivial supersolid phase. 相似文献
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Forouzan Zonouzi Alireza Shayesteh Taher Alizadeh Hamid Dezhampanah Bahram Ghalami-Choobar Afsaneh Zonouzi 《中国化学会会志》2020,67(1):41-45
The (E)-2-hydroxy-5-(aryldiazenyl) benzaldehydes (azo dyes 1–4 ) were synthesized in high purity. As they are insoluble in water, the usual analytical methods cannot be utilized to determine their pKa values. Cyclic voltammetry was experimentally used to determine their pKa values in DMSO solvent. In addition, computational methods and a conductor-like screening model (COSMO) were used to calculate the solvent effect. , , Kexchange, and pKa values were estimated for the azo dyes being studied using the BP86, TPSS, B3LYP, PBE0, TPSSh, and PW6B95 density functionals in def2-TZVP basis sets. The obtained mean absolute deviations (MADs) indicate that the results of BP86, PBE0, and PW6B95 functionals are in good agreement with experimental values. 相似文献
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Forouzan Aboufazeli Hamid Reza Lotfi Zadeh Zhad Omid Sadeghi Mohammad Karimi Ezzatolla Najafi 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(1):18-24
In this work, MCM-41 (Mobil Composition of Matter number 41) nanoporous silica has been synthesized and characterized by X-ray powder diffraction and IR spectroscopy. In the next step, poly-thiophene was coated on the nanoporous silica in order to increase its surface area. This composite was characterized by X-Ray powder diffraction, High resolution transmission electronic microscopy micrograph (HRTEM), elemental analysis (CHNS) and Thermal analysis (TG/DTA). The application of this composite was investigated in mercury ions removal from waste water prior to determination by inductively coupled plasma atomic emission spectroscopy (ICP-OES). In order to investigate the effect of nanoporous structure on the efficiency of this composite, the same composite without porous structure has been synthesized and the results were compared. 相似文献
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Traffic of leukocytes in microvascular networks (particularly through arteriolar bifurcations and venular convergences) affects the dynamics of capillary blood flow, initiation of leukocyte adhesion during inflammation, and localization and development of atherosclerotic plaques in vivo. Recently, a growing research effort has been focused on fabricating microvascular networks comprising artificial vessels with more realistic, rounded cross-sections. This paper investigated the impact of the cross-sectional geometry of microchannels on the traffic of leukocytes flowing with human whole blood through a non-symmetrical bifurcation that consisted of a 50 μm mother channel bifurcating into 30 μm and 50 μm daughter branches. Two versions of the same bifurcation comprising microchannels with rectangular and rounded cross-sections were fabricated using conventional multi-layer photolithography to produce rectangular microchannles that were then rounded in situ using a recently developed method of liquid PDMS/air bubble injection. For microchannels with rounded cross-sections, about two-thirds of marginated leukocytes traveling along a path in the top plane of the bifurcation entered the smallest 30 μm daughter branch. This distribution was reversed in microchannels with rectangular cross-sections--the majority of leukocytes traveling along a similar path continued to follow the 50 μm microchannels after the bifurcation. This dramatic difference in the distribution of leukocyte traffic among the branches of the bifurcation can be explained by preferential margination of leukocytes towards the corners of the 50 μm mother microchannels with rectangular cross-sections, and by the additional hindrance to leukocyte entry created by the sharp transition from the 50 μm mother microchannel to the 30 μm daughter branch at the intersection. The results of this study suggest that the trajectories of marginated leukocytes passing through non-symmetrical bifurcations are significantly affected by the cross-sectional geometry of microchannels and emphasize the importance of using microfludic systems with geometrical configurations closely matching physiological configurations when modeling the dynamics of whole blood flow in the microcirculation. 相似文献
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The Gerotor pumps have a vast number of applications in industries and automobiles. The flow rate irregularity and wear rate
proportional factor influence on the lifetime of the Gerotor pumps. In this paper, the optimization problem cost functions
and constraints have been developed according to volumetric, dynamic and geometric properties. In order to have general optimum
solution and reduce number of design variables, all variables have changed to non-dimensional variables by using the outer
rotor lobe center radius which causes the non-dimensional cost functions too. The multi-objective optimization problem has
been changed to single objective optimization problem by using a multi-objective optimization classical method. The single
objective optimization problem has been solved by using of a mixed integer nonlinear optimization algorithm. The optimization
programming has been implemented for several values of number of the outer rotor teeth, non-dimensional displacement and rotors
width. On the other hand the influence of varied parameter such as number of outer rotors teeth, the value of non-dimensional
displacement and non-dimensional rotor width have been surveyed on each of cost functions. The results show in constant input
torque, as using greater number of outer rotor teeth up to critical value improves the wear of teeth. Also optimum value of
flow rate irregularity in odd values of outer rotor teeth is smaller than even ones. At last for having better comparison,
two sample commercial pumps have been optimized. The results show both wear rate proportional factor and flow irregularity
have been significantly improved. 相似文献
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Gholamian Forouzan Chaloosi Marzieh Husain Syed Wagif Dehghani Hossein 《平面色谱法杂志一现代薄层色谱法》2001,14(4):296-299
JPC – Journal of Planar Chromatography – Modern TLC - High-performance thin-layer chromatography (HPTLC) has been used for separation and quantitation of components of high explosives... 相似文献
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Louis Schutz Forouzan Kazemi Elby Mackenzie Jean-Yves Bergeron Eric Gagnon Jerome P. Claverie 《Journal of polymer science. Part A, Polymer chemistry》2021,59(4):321-328
Vast quantities of the natural terpene (R)-limonene can be collected from food waste. Epoxidation of its two double bonds provides limonene dioxide (LDO), a difunctional epoxy monomer. However, LDO is a mixture of four isomers, two of which (trans-LDO) are actually difunctional while the others (cis-LDO) have one epoxide group which is significantly less reactive, as revealed by Fourier transformed infrared spectroscopic analysis of formulations cross-linked with polyethylene imine. These results are also confirmed when preparing epoxy formulations using respectively cis or trans isomers. From DFT calculations, the reactivity of each epoxide group of LDO has been assessed in model reactions with primary and secondary amines, in the presence of amine or alcohol hydrogen-bond donors. The kinetics of cross-linking has also been probed by differential scanning calorimetry. As measured by dynamic mechanical analysis, the resulting epoxy resins based on trans isomers have a storage modulus of ca 1GPa at room temperature and a glass transition temperature (Tg) of 70°C. These results demonstrate that trans LDO is a promising bio-based epoxy monomer, which could be used as an alternative to petroleum-based epoxy monomers. 相似文献
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Mohammad Karimi Forouzan Aboufazeli Hamid Reza Lotfi Zadeh Zhad Omid Sadeghi Ezzatollah Najafi 《燃料化学学报》2013,41(1):91-95
In this work,fullerene was modified by platinum,ruthenium,tin and tungsten nanoparticles.The material was characterized by XRD,ICP-OES and TEM micrograph.The average nanoparticle size on fullerene was 5-8 nm.The application of this material was investigated as a catalyst for methanol oxidation in direct methanol fuel cell.A glassy carbon electrode was modified by Pt/Ru/Sn/W fullerene and electrocatalytic activity of the electrode toward methanol oxidation in basic medium has been demonstrated and investigated using cyclic voltammetry.The catalyst showed good reactivity for methanol oxidation. 相似文献
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Forouzan Gholamian Mahdi Ansari Mohammad Abdullah Farideh Bataghva Sara Ghariban-Lavasani 《高分子科学》2013,31(10):1372-1381
The interaction of a new neutral polymeric bonding agent (NPBA) containing N-Vinylpyrrolidone units with two types of oxidizers (ammonium perchlorate and Keto-RDX) was investigated by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). NPBA forms a layer of film on the surface of oxidizers. The paper gives hypothetical mechanisms for improving significantly mechanical properties by addition of the neutral polymeric bonding agent (NPBA). 相似文献