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31.
Yazdani Elahe Kazemi Miraki Maryam Salamatmanesh Arefe Azarnia Jamshid Azizi Kobra Ghandi Leila Heydari Akbar 《Research on Chemical Intermediates》2019,45(4):1775-1793
Research on Chemical Intermediates - A novel copper(II)–salen complex was immobilized on the surface of magnetite nanoparticles using chitosan as a linker. This system exhibits superior... 相似文献
32.
Ali Eftekhari Bahareh Yazdani 《Journal of polymer science. Part A, Polymer chemistry》2010,48(10):2204-2213
Because of its special chemical composition, graphite oxide has peculiar influences on electrochemical processes. The existence of various functional groups significantly affects electropolymerization processes and the formation of conductive polymers. Electrochemical synthesis of polyaniline (as a prototype of conductive polymers) on a paste‐based substrate of graphite oxide was investigated. In this case, the electropolymerization is significantly different from conventional cases, and the polymer is generated just during the first potential cycle. This can be attributed to the fact that graphite oxide can assist the monomer oxidation. Alternatively, electropolymerization was successfully performed inside the graphite oxide layers via electrochemical treatment of aniline‐intercalated graphite oxide in the supporting electrolyte. Although these phenomena are related to the chemical composition of graphite oxide, the graphite prepared by the reduction of graphite oxide also displayed some advantages for the electropolymerization (over natural graphite). There is an emphasis on the morphological investigations throughout this study, because novel morphologies were observed in the system under investigation. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2204–2213, 2010 相似文献
33.
M. Hesani A. Yazdani B. Abedi Ravan M. Ghazanfari 《Solid State Communications》2010,150(13-14):594-597
Some size-dependent characteristics of FeCo nanoparticles are investigated in this paper. The nanoparticles are fabricated using a coprecipitation route and their sizes are controlled by changing the reaction time. Transverse electron microscopy (TEM) images show that the nanoparticles are all spherical with an average size of 2–6 nm. The average size obtained from X-ray diffraction (XRD) measurements is in the range 1–3 nm. Magnetic measurements reveal that the nanoparticles are ordered ferromagnetically and have a high coercivity of about 500 Oe. In our measurements, the coercivity was decreased with decreasing particle size, indicating that the nanoparticles were in a single-domain region. Production of FeCo nanoparticles with high coercivity and fine dimension is highly promising for future recording media technology. 相似文献
34.
Alireza Yazdani Leonardo Dueñas-Osorio Qilin Li 《Communications in Nonlinear Science & Numerical Simulation》2013,18(10):2722-2732
To date, a number of metrics have been proposed to quantify inherent robustness of network topology against failures. However, each single metric usually only offers a limited view of network vulnerability to different types of random failures and targeted attacks. When applied to certain network configurations, different metrics rank network topology robustness in different orders which is rather inconsistent, and no single metric fully characterizes network robustness against different modes of failure. To overcome such inconsistency, this work proposes a multi-metric approach as the basis of evaluating aggregate ranking of network topology robustness. This is based on simultaneous utilization of a minimal set of distinct robustness metrics that are standardized so to give way to a direct comparison of vulnerability across networks with different sizes and configurations, hence leading to an initial scoring of inherent topology robustness. Subsequently, based on the inputs of initial scoring a rank aggregation method is employed to allocate an overall ranking of robustness to each network topology. A discussion is presented in support of the presented multi-metric approach and its applications to more realistically assess and rank network topology robustness. 相似文献
35.
Mohammad Joshaghani Davoud Yazdani Ali Akbar Zinatizadeh 《Journal of the Iranian Chemical Society》2017,14(11):2449-2456
Zero-valent iron-modified Degussa P25-TiO2/ZnO nanocomposites (denoted as P25/Fe0/ZnO) were designed and prepared via Fe0 impregnation of P25-TiO2/ZnO and then were employed in the visible-light photocatalytic degradation of p-nitrophenol (PNP) in the presence of [K2S2O8]. Central composite design was applied for response surface modeling (RSM) to understand the influence of selected factors (pH, [Fe0] wt% and [K2S2O8] concentration) on the degradation of PNP and to determine the interaction between the factors. The maximal PNP degradation efficiency (86.9%) was obtained with P25/1.5 wt% Fe0/ZnO at 3 mg/L of [K2S2O8] concentration and pH 7.5. In addition, the RSM showed a satisfactory correlation between the experimental and predicted values of PNP degradation. The P25/Fe0/ZnO photocatalyst performance was also examined degrading methyl orange and phenol and high degradation efficiency, 82 and 99%, was achieved, respectively. The structure, morphology, light absorption and photocatalytic properties of as-prepared P25/Fe0/ZnO were studied using TEM, BET, XRD, FTIR and DRS. 相似文献
36.
Rahman Hosseinzadeh Mahmood Tajbakhsh Alireza Shakoori Mohammad Yazdani Niaki 《Monatshefte für Chemie / Chemical Monthly》2004,135(10):1243-1249
Summary. 2,6-Dicarboxypyridinium chlorochromate (2,6-DCPCC) was found to be an efficient reagent for the conversion of acetals, thioacetals, and 1,1-diacetates to their corresponding carbonyl compounds under neutral and anhydrous conditions in good to excellent yields. Selective deprotection of acetals or 1,1-diacetates in the presence of thioacetals at room temperature is also observed with this reagent. 相似文献
37.
The Prisoner’s Dilemma and Snowdrift games are the main theoretical constructs used to study the evolutionary dynamics of cooperation. In large, well-mixed populations, mean-field models predict a stable equilibrium abundance of all defectors in the Prisoner’s Dilemma and a stable mixed-equilibrium of cooperators and defectors in the Snowdrift game. In the spatial extensions of these games, which can greatly modify the fates of populations (including allowing cooperators to persist in the Prisoner’s Dilemma, for example), lattice models are typically used to represent space, individuals play only with their nearest neighbours, and strategy replacement is a function of the differences in payoffs between neighbours. Interestingly, certain values of the cost–benefit ratio of cooperation, coupled with particular spatial configurations of cooperators and defectors, can lead to ‘global standoffs’, a situation in which all cooperator–defector neighbours have identical payoffs, leading to the development of static spatial patterns. We start by investigating the conditions that can lead to ‘local standoffs’ (i.e., in which isolated pairs of neighbouring cooperators and defectors cannot overtake one another), and then use exhaustive searches of small square lattices (4×4 and 6×6) of degree k=3,k=4, and k=6, to show that two main types of global standoff patterns–‘periodic’ and ‘aperiodic’–are possible by tiling local standoffs across entire spatially structured populations. Of these two types, we argue that only aperiodic global standoffs are likely to be potentially attracting, i.e., capable of emerging spontaneously from non-standoff conditions. Finally, we use stochastic simulation models with comparatively large lattices (100×100) to show that global standoffs in the Prisoner’s Dilemma and Snowdrift games do indeed only (but not always) emerge under the conditions predicted by the small-lattice analysis. 相似文献
38.
K. Hosseini E. Yazdani Bejarbaneh A. Bekir M. Kaplan 《Optical and Quantum Electronics》2017,49(7):241
This paper aims to conduct an analytical study into some nonlinear models of pseudoparabolic type, including the Oskolkov, Oskolkov–Benjamin–Bona–Mahony–Burgers, and Benjamin–Bona–Mahony–Peregrine–Burgers equations. A number of new exact solutions for these pseudoparabolic type equations have been derived based on the modified Kudryashov method that its calculations are performed in a symbolic computation system known as Maple. 相似文献
39.
Polyaniline nanoparticle (nPANI) was successfully synthesized through ultrasonic-assisted reverse microemulsion polymerization method. The effect of four parameters including concentration of aniline (ANI) as monomer, molar ratio of dodecybenzene sulfonic acid (DBSA) as surfactant to ANI, molar ratio of ammonium peroxydisulfate (APS) as oxidant to ANI and polymerization temperaturewere systematically studied in terms of the structural characterizations of nPANI by applying the Taguchi method of experimental design. Data analysis indicated that there is a dependency between conductivity and particle size in the nanoscale; the maximum conductivity of nPANI was obtained when the diameter of the particles was 30?nm. 相似文献
40.
Peter Borwein Kwok-Kwong Stephen Choi Soroosh Yazdani 《Proceedings of the American Mathematical Society》2001,129(1):19-27
The Fekete polynomials are defined as
where is the Legendre symbol. These polynomials arise in a number of contexts in analysis and number theory. For example, after cyclic permutation they provide sequences with smallest known norm out of the polynomials with coefficients.
The main purpose of this paper is to prove the following extremal property that characterizes the Fekete polynomials by their size at roots of unity.
Theorem 0.1. Let with odd and . If
then must be an odd prime and is . Here
This result also gives a partial answer to a problem of Harvey Cohn on character sums.