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41.
Three adducts of the N,N′‐bidentate aromatic base 4,4′‐dimethyl‐2,2′‐bipyridine (dmbpy) of lead(II) salts, [Pb(dmbpy)2(NO3)2] ( 1 ), [Pb(dmbpy)2(ClO4)2] ( 2 ) and [Pb(dmbpy)(NCS)2]n ( 3 ) have been synthesized and characterized by elemental analysis, IR, 1H‐NMR and 13C‐NMR spectroscopy and studied by thermal analysis as well as X‐ray crystallography. The single‐crystal structures of these complexes show that the 6s electrons of lead(II) constitute a stereochemically active lone pair (SALP). The coordination numbers of the PbII ions are eight and seven, respectively. The supramolecular features in these complexes are guided/controlled by weak directional intermolecular interactions. 相似文献
42.
Farzin Ghanadi Maziar Arjomandi Benjamin Cazzolato Anthony Zander 《International Journal of Computational Fluid Dynamics》2014,28(5):219-231
In this study, a large eddy simulation of the three-dimensional shear flow over a flow-excited Helmholtz resonator has been implemented. The simulations have been performed over a wide range of flow speeds to analyse the effect of the inlet flow properties on the excitation condition. For validation proposes, the results obtained from the numerical simulations have been compared with published experimental data and show that numerical modelling provides an accurate representation of the pressure fluctuations inside the cavity. The main objective of this paper is to gain an understanding of the flow features over a flow-excited Helmholtz resonator. To this end, using the numerical model, the interaction of a turbulent boundary layer with a Helmholtz resonator has been considered, and the characteristics of the flow inside the resonator and over the orifice for various flow conditions are also analysed. 相似文献
43.
Alam Abedini Elias Saion Farzin Larki 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(3):983-987
Colloidal Cu–Al nanoparticles were prepared in an aqueous polyvinyl alcohol solution containing copper chloride and aluminum chloride as precursors, isopropanol as a scavenger of hydroxyl radicals, and distilled water as a solvent. The gamma irradiations were carried out in a 60Co gamma source chamber with different doses up to 120 kGy. The formation of Cu–Al nanoparticles has been observed initially by the change in color of the colloidal samples from colorless to brown. The nanoparticles properties were characterized by transmission electron microscopy, energy dispersive X-ray spectrometry, and UV–Vis spectrophotometer. At a constant Cu/Al molar ratio, size of the nanoparticles can be well controlled by varying the precursors concentration and radiation dose. The average particle diameter increases with increase of precursors concentration and decreases with increase of dose. This is owing to the competition between nucleation process, aggregation process, and ions association in the formation of nanoparticles during irradiation. 相似文献
44.
Dr. Farzin Marandi Parisa Hassanmohammadi Hoong‐Kun Fun Ching Kheng Quah 《无机化学与普通化学杂志》2012,638(2):461-465
Two novel 3D lead(II)‐azido and ‐thiocyanato coordination polymers with isonicotinate acid N‐oxide (INO) as the coligand were synthesized and characterized by elemental analysis, IR, and 1H NMR spectroscopy and were also studied using X‐ray crystallography technique. These complexes have the formulas [Pb(INO)(NCS)]n ( 1 ) and [Pb(INO)(N3)(H2O)]n ( 2 ). 相似文献
45.
Farzin Emami Mohsen Hatami Alireza Keshavarz Amir Hosein Jafari 《Optical and Quantum Electronics》2009,41(6):429-439
In this paper we simulated the pulse propagation and the switching effects in nonlinear fiber Bragg gratings using a combination
of Fourier series analysis technique and Jacobi iterative method. The effects of nonlinearity and dispersion on the pulse
propagation have been studied extensively. An all optical self switch was designed by this simulation. This switch is operated
based on the input power. 相似文献
46.
Keshavarz Farzin Mirabdolah Lavasani Arash Bayat Hamidreza 《Journal of Thermal Analysis and Calorimetry》2019,135(2):1211-1228
Journal of Thermal Analysis and Calorimetry - In the present study, the effect of nanofluid and distribution density of fin on thermal–hydraulic performance of a heat sink with drop-shaped... 相似文献
47.
Structural Chemistry - The authors regret that the Acknowledgments of the original version of this article was incorrect. 相似文献
48.
Kazemi Faramarz Arianpour Farzin Rezaie Hamid Reza 《Journal of Thermal Analysis and Calorimetry》2020,139(1):67-73
Journal of Thermal Analysis and Calorimetry - In this research, formation mechanism and kinetics of vacuum carbothermal synthesis of zirconium carbide using zirconium acetate and sucrose are... 相似文献
49.
In this paper we relate ‐designs to a forbidden configuration problem in extremal set theory. Let denote a column of 1's on top of 0's. Let denote the matrix consisting of rows of 1's and rows of 0's. We consider extremal problems for matrices avoiding certain submatrices. Let be a (0, 1)‐matrix forbidding any submatrix . Assume is ‐rowed and only columns of sum are allowed to be repeated. Assume that has the maximum number of columns subject to the given restrictions. Assume is sufficiently large. Then has each column of sum and exactly once and, given the appropriate divisibility condition, the columns of sum correspond to a ‐design with block size and parameter . The proof derives a basic upper bound on the number of columns of by a pigeonhole argument and then a careful argument, for large m, reduces the bound by a substantial amount down to the value given by design‐based constructions. We extend in a few directions. 相似文献
50.
Farzin Taghipourian Iraj Mahdavi Nezam Mahdavi-Amiri Ahmad Makui 《Applied Mathematical Modelling》2012
Hub location problem has been used in transportation network to exploit economies of scale. For example, a controversial issue in the planning of air transportation networks is inclement weather or emergency conditions. In this situation, hub facilities would not be able to provide a good service to their spoke nodes temporarily. Thus, some other kinds of predetermined underutilized facilities in the network are used as virtual hubs to host some or all connections of original hubs to recover the incurred incapacitation and increase network flexibility and demand flow. In such an unexpected situation, it is not unreasonable to expect that some information be imprecise or vague. To deal with this issue, fuzzy concept is used to pose a more realistic problem. Here, we present a fuzzy integer liner programming approach to propose a dynamic virtual hub location problem with the aim of minimizing transportation cost in the network. We examine the effectiveness of our model using the well-known CAB data set. 相似文献