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31.
Thin nanocrystalline amorphous NiTi film was deposited on Si substrate using DC magnetron sputtering. The as-deposited NiTi thin film was crystallized by heat treatment at 500 °C for 1 h. The crystal structure, surface morphology, microstructure and surface chemistry of the deposited films were studied using X-ray diffraction, atomic force microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy (XPS), respectively. Corrosion behaviour was assessed in Ringer’s solution at 37 °C by open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy as a function of exposure time. OCP values indicate that the tendency for the formation of a spontaneous oxide film is greater for the NiTi thin films than the bulk NiTi. Long time exposure to Ringer’s solution was found to have a great effect on the corrosion behaviour of the samples. Significantly low corrosion current density was obtained for the annealed NiTi film from the potentiodynamic polarization curves indicating a typical passive behaviour, but as-deposited film and bulk NiTi alloy exhibited breakdown of passivity at potentials approximately +1.4 V (vs. SCE). XPS showed that the oxide film formed on the annealed NiTi thin film mainly composed of Ti oxides, and no evidence of Ni was found up to 8.2 nm beneath the top surface, suggesting the excellent corrosion resistance of this sample in Ringer’s solution. 相似文献
32.
Nader Ghaffari Khaligh 《催化学报》2014,35(7):1036-1042
3-Methyl-1-sulfonic acid imidazolium hydrogen sulfate has been used as an efficient, halogen-free,and reusable Brnsted acidic ionic liquid catalyst for the synthesis of ethyl-4-aryl/heteryl- hexahydro-trimehtyl-5-oxoquinoline-3-carboxylates via the one-pot condensation of dimedone with aryl/heteryl aldehydes, ethyl acetoacetate, and ammonium acetate under solvent-free conditions. This method has the advantage of being clean and simple, as well as providing the desired product in high yield over a short reaction time. Furthermore, the catalyst could be recycled and reused four times without any discernible reduction in activity. 相似文献
33.
Nader Ghaffari Khaligh 《催化学报》2014,35(9):1497-1503
1,1''-Butylenebispyridinium hydrogen sulfate is an efficient, halogen-free and reusable Brönsted ionic liquid catalyst for the synthesis of ethyl-4-aryl/heteryl-hexahydro-trimehtyl-5- oxoquinoline-3-carboxylates by the one-pot condensation of dimedone, aryl/heteryl aldehydes, ethyl acetoacetate, and ammonium acetate under solvent-free conditions. This method has the advantages of high yield, clean reaction, simple methodology, and short reaction time. The ionic liquid can be recycled five times without significant loss of the catalytic activity. 相似文献
34.
Nader Ghaffari Khaligh 《催化学报》2014,(11)
A simple and facile synthesis of 12-arylbenzo[g]indeno[2,1-b]quinoline-6,11,13-trione deriv-atives was accomplished by the one-pot condensation of 2-hydroxynaphthalene-1,4-dione, aryl aldehydes, 2H-ind... 相似文献
35.
Here, we present a method to synthesize expandable spherical polystyrene beads containing well-dispersed water microdroplets. The beads, 2–3 mm in diameter, were prepared through surfactant-free Pickering emulsion polymerization in water-in-oil-in-water (w/o/w) system using cross-linked starch nanoparticles (CSTN) as emulsifier. The CSTNs were in situ surface-modified by styrene maleic anhydride copolymer as confirmed by infrared spectroscopy and contact angle analysis. The entrapped water microdroplets with the average size of 3–4 μm were shown to be surrounded by a dense layer of the CSTN. The number droplet density as well as water encapsulation efficiency in the polystyrene beads increased with the CSTN concentration. Furthermore, regardless of CSTN content, all samples exhibited high encapsulation stability of over 68 % after 3 months. These characteristics along with good expansion behavior suggest the synthesized beads as expandable polystyrene containing water as a green blowing agent. 相似文献
36.
Soliman Mohamed A. Mohamed Nader M. A. Takamiya Koichi Sekimoto Shun Inagaki Makoto Oki Yuichi Ohtsuki Tsutomu 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(3):1099-1107
Journal of Radioanalytical and Nuclear Chemistry - To assess the capability of Kyoto University Research Reactor to supply the domestic needs of medical isotopes, its neutron flux has been fully... 相似文献
37.
Noroozi Pesyan Nader Rezanejade Bardajee Ghasem Kashani Elmira Mohammadi Marzieh Batmani Hana 《Research on Chemical Intermediates》2020,46(1):347-367
Research on Chemical Intermediates - An efficient, rapid, and environmentally benign Ni(II)-Schiff base/SBA-15-catalyzed one-pot three-component cyclocondensation process was described via the... 相似文献
38.
V. S. Kharlamov D. V. Kulikov Yu. V. Trushin P. Nader P. Mazri Th. Stauden J. Pezoldt 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(2):241-244
Structures grown using the technique of molecular-beam epitaxy during deposition of carbon and/or germanium atoms on an Si(111)
surface were investigated experimentally and theoretically. Experimental profiles of in-depth component distribution were
obtained using SIMS-profiling, whereas a complex technique of computer simulation taking into account diffusion and ballistic
processes was applied for the calculated profiles. 相似文献
39.
Konstantin Pankrashkin Svetlana Roganova Nader Yeganefar 《Integral Equations and Operator Theory》2011,71(2):199-223
We study Laplace-type operators on hybrid manifolds, i.e., on configurations consisting of closed two-dimensional manifolds
and one-dimensional segments. Such an operator can be constructed by using the Laplace–Beltrami operators on each component
with some boundary conditions at the points of gluing. The large spectral parameter expansion of the trace of the second power
of the resolvent is obtained. Some questions of the inverse spectral theory are addressed. 相似文献
40.
We propose a new type of two-dimensional (2D) photonic crystal L-shaped bent waveguides based on ring resonators with an acceptable bandwidth. The proposed structure mechanism is based on coupling between a waveguide and a ring resonator. This structure is designed and verified by finite-difference time-domain (FDTD) computation. Our simulation using this method gets over 90% output. 相似文献