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51.
Bahrami Mojgan Borhani Gholam Hussein Bakhshi Saeed Reza Ghasemi Ali 《Journal of Sol-Gel Science and Technology》2017,81(3):921-933
Journal of Sol-Gel Science and Technology - In this study, the Taguchi method was used to design of experiment to obtain optimum conditions for hybrid Si–Zr sol–gel coating doped with... 相似文献
52.
Covalent bonding of magnetic Fe3O4 nanoparticles to aminopropyl‐functionalized magnesium phyllosilicate clay: Synthesis and cytotoxic potential investigation 下载免费PDF全文
Hasan Nasrabadi Zahra Amirghofran Ahmadreza Esmaeilbeig Mehrangiz Bahrami S. Jafar Hoseini 《应用有机金属化学》2018,32(2)
Stable water dispersion of Fe3O4 magnetic nanoparticles (NPs) were successfully synthesized by using 3‐glycidoxypropyltrimethoxysilane (GPTMS) and Mg‐phyllo (organo) silicate known as aminoclay (AC) containing pendant amino groups with the approximate composition (R8Si8Mg6O16(OH)4, R = CH2CH2CH2NH2). The Fe3O4‐GPTMS magnetic NPs with an epoxy functional group are suitable for forming a covalent bond with the amine group of aminoclay in an epoxy ring opening reaction. Appropriate Fe3O4‐GPTMS‐aminoclay (FG‐AC) magnetic composite are promising carriers for the targeting and delivery of platinum‐based anticancer drugs. Analysis of the cytotoxicity of the nanostructures on a K562 leukemia cell line using a colorimetery assay shows that both the FG‐AC and cis‐platin/FG‐AC magnetic composite were biocompatible. The nanostructures characterizations were investigated by Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy and energy dispersive analysis of X‐ray techniques. Magnetic measurement revealed that the saturated magnetization of the FG‐AC nanocomposite reached 7.6 emu/g and showed the characteristics of magnetism. 相似文献
53.
Hamed Raeisifard Mehdi Zamanian Mansour Nikkhah Bahrami Aghil Yousefi-Koma Hafez Raeisi Fard 《Journal of sound and vibration》2014
In this article, a comprehensive nonlinear analysis for a piezoelectric laminated micro system around its static deflection is presented. This static deflection is created by an electrostatic DC control voltage through an electrode plate. The micro system beam is assumed as an elastic Euler-Bernoulli beam with clamped-free end conditions. The dynamic equations of this model have been derived by using the Hamilton method and considering the nonlinear inertia, curvature, piezoelectric and electrostatic terms. The static and dynamic solutions have been achieved by using the Galerkin method and the multiple-scales perturbation approach, respectively. The results are compared with numerical and other existing experimental results. By studying the primary resonance excitation, the effects of different parameters such as geometry, material and excitations voltage on the system?s softening and hardening behaviors are evaluated. In a piezoelectrically actuated micro system it was showed that because of existence of curvature and inertia nonlinear terms a small change in excitation amplitude can lead to the formation and expansion of nonlinear response. In this paper, it is demonstrated that by applying an electrostatic DC control voltage, these nonlinearities can be controlled and altered to a linear domain. This model can be used to design a nano or micro-scale smart device. 相似文献
54.
Aidin Bahrami Sirous Yourdkhani Mehdi D. Esrafili Milad Bahrami Nasser L. Hadipour 《Structural chemistry》2013,24(4):1273-1279
Density functional theory calculations at the B3LYP/6-31G(d) and B3LYP/6-31+G(d) levels were carried out for the adsorption of NH3 on three symmetric isomers of B80 {C 1, T h, I h}. To investigate the binding features of B80 isomers with NH3, different studies including the structural and electronic parameters, the 14N electric field gradient tensors and the atoms in molecules (AIM) properties were considered. The calculated parameters by these investigations can be used as powerful tools to find out some of the unknown aspects of electronic structures of the boron buckyball and its isomers. According to previous studies, boron buckyball as an amphoteric and a hard molecule has two distinct reactive sites defined as cap and frame which act as an acid and a base, respectively. Regarding the obtained results in this study, all the isomers had the same exposure when NH3 molecule reacted with the external wall of B80. For instance, the stability of N–B bond in the cap site was significantly more than the stability of N–B bond in the frame. Moreover, the adsorption of NH3 on frame site showed a considerable reduction in HOMO–LUMO energy gap. According to AIM theory, an electrostatic nature was observed for N–B interaction. Concerning the selected isomers of buckyball, the capability of the NH3–B80 complexes to localize electron at the N–B bond critical points depend on the reaction sites significantly. In general, 14N nuclear quadruple coupling constants and asymmetry parameter reveal a remarkable effect of NH3 adsorption on electronic structure of the B80. 相似文献
55.
Ghahremani Masoumeh Bahrami Hamed Douroudgari Hamed Vahedpour Morteza 《Structural chemistry》2020,31(1):411-421
Structural Chemistry - Sulfinamides, as an asymmetric synthesizer, especially in drug synthesis, play critical roles in organic chemistry. In this study, the gas phase ion energetics data including... 相似文献
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57.
A simple graphical approach to predict local residue conformation using NMR chemical shifts and density functional theory 下载免费PDF全文
Hoora Shaghaghi Hossein Pasha Ebrahimi Fariba Fathi Niloufar Bahrami Panah Mehdi Jalali‐Heravi Mohsen Tafazzoli 《Journal of computational chemistry》2016,37(14):1296-1305
The dependency of amino acid chemical shifts on φ and ψ torsion angle is, independently, studied using a five‐residue fragment of ubiquitin and ONIOM(DFT:HF) approach. The variation of absolute deviation of 13Cα chemical shifts relative to φ dihedral angle is specifically dependent on secondary structure of protein not on amino acid type and fragment sequence. This dependency is observed neither on any of 13Cβ, and 1Hα chemical shifts nor on the variation of absolute deviation of 13Cα chemical shifts relative to ψ dihedral angle. The 13Cα absolute deviation chemical shifts (ADCC) plots are found as a suitable and simple tool to predict secondary structure of protein with no requirement of highly accurate calculations, priori knowledge of protein structure and structural refinement. Comparison of Full‐DFT and ONIOM(DFT:HF) approaches illustrates that the trend of 13Cα ADCC plots are independent of computational method but not of basis set valence shell type. © 2016 Wiley Periodicals, Inc. 相似文献
58.
A sensitive and fast method for the simultaneous determination of trace amounts of nickel and cadmium in real samples has been described using differential pulse adsorptive stripping voltammetry (DPASV) by adsorptive accumulation of the N,N′‐bis(salicylaldehydo)4‐carboxyphenylenediamine (BSCPDA)–complex on the hanging mercury drop electrode (HMDE). As supporting electrolyte 0.02 mol L?1 ammonia buffers containing ligand has been used. Optimal analytical conditions were found to be: BSCPDA concentration of 42 μM, pH 9.6 and adsorption potential at ?50 mV versus Ag/AgCl. With an accumulation time of 20 s, the peaks current are proportional to the concentration of nickel and cadmium over the 1–180, and 0.5–200 ng mL?1 with detection limits of 0.06 and 0.03 ng mL?1 respectively. The sensitivity of method for determination of nickel and cadmium were obtained 0.54 and 0.98 nA mL ng?1, respectively. The procedure was applied to simultaneous determination of nickel and cadmium in some real and synthetic artificial samples with satisfactory results. 相似文献
59.
Amanj Kheradmand Ahmad Ramazani Saadat Abadi Farhad Khorasheh Morteza Baghalha Hiva Bahrami 《Polymer Science Series B》2016,58(3):271-277
In this study, we have reported the preparation of bi-supported Ziegler-Natta catalysts using magnesium ethoxide and graphene oxide as support. The polymerization process was carried out in slurry phase using triisobutylaluminum as a co-catalyst.The XRD analysis of TiCl4/graphene oxide/Mg(OEt)2 catalyst demonstrated that the space between the layers of graphene oxide had increased to 0.2 nm.The catalyst was characterized by XPS, BET, BJH, SEM, and TGA. The catalyst activity was studied for various Al/Ti molar ratios, and the catalyst activity was optimum at Al/Ti molar ratio of 315. 相似文献
60.
Mohammad Ali Bodaghifard Sajad Asadbegi Zahra Bahrami 《Journal of the Iranian Chemical Society》2017,14(2):365-376
(Triazinediyl)bis sulfamic acid-functionalized silica-coated magnetite nanoparticles have been prepared and applicated as an efficient catalyst for synthesis of mono-, bis-, tris- and spiro-perimidines. The desired products have been synthesized in high purity and good yields. The workup procedure of reaction is simple. The catalyst was easily separated from the reaction mixture with the assistance of an external magnetic field and reused for several runs without deterioration in catalytic activity. The core/shell nanoparticles were characterized by transmission electron microscopy, scanning electron microscope, powder X-ray diffraction, energy dispersive spectrometer, Fourier transform infrared spectroscopy and vibrating sample magnetometer. 相似文献