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102.
Reihaneh Malakooti Ghasem Rezanejade Bardajee Somayyeh Hadizadeh Hassan Atashin Hadiseh Khanjari 《Transition Metal Chemistry》2014,39(1):47-54
An iron Schiff base complex was encapsulated in SBA-15 mesoporous silica to afford a Fe(III)-Schiff base/SBA-15 heterogeneous nanocatalyst for the synthesis of pyridopyrazine and quinoxaline heterocycles. These reactions proceeded in water with excellent yields. The catalyst was characterized by physico-chemical and spectroscopic methods and found to retain the characteristic channel structures of the SBA-15, allowing good accessibility of the encapsulated metal complex. 相似文献
103.
Voltammetry of microparticles has been used in this work for the qualitative and quantitative analyses of zinc, tin, lead
and copper in binary, ternary or quaternary alloy samples. The analyses were carried out by spiking small amounts of the metals
into a carbon paste electrode, after which they were anodically stripped off using differential pulse voltammetry. The work
involved four separate experiments. The first one examined the type of electrolyte, which is suitable to identify the four
elements. More specifically, the aim was to examine in which electrolyte all elements can be measured simultaneously–as would
be the case in a quaternary copper alloy–without seeing any overlap in their current peaks. The second experiment focused
on optimizing the measurement conditions with the aim of having the current peaks of each element well separated from the
others. For this part, we made use of the central composite design. The aims were to: (i) maximize the separation between
current peaks, (ii) determine which variable has a higher impact on the response, (iii) give an insight in the robustness
of the method close to the optimum conditions and (iv) eventually show interactions between variables. In the third experiment,
the four elements were quantified in their binary mixtures. Here, the percentage of the oxidation current for each metal,
which is directly related to the ratio of the metal in the binary matrices, was employed for the calibration. Finally, in
the last experiment, the elements were quantified in two real quaternary samples: a brass and a lead bronze. 相似文献
104.
On the approximate solution of integro-differential equations arising in oscillating magnetic fields
In this work, we propose the Shannon wavelets approximation for the numerical solution of a class of integro-differential equations which describe the charged particle motion for certain configurations of oscillating magnetic fields. We show that using the Galerkin method and the connection coefficients of the Shannon wavelets, the problem is transformed to an infinite algebraic system, which can be solved by fixing a finite scale of approximation. The error analysis of the method is also investigated. Finally, some numerical experiments are reported to illustrate the accuracy and applicability of the method. 相似文献
105.
T. Frederico A. Delfino M. R. Hadizadeh Lauro Tomio M. T. Yamashita 《Few-Body Systems》2013,54(5-6):559-568
We report recent advances on the study of universal weakly bound four-boson states from the solutions of the Faddeev-Yakubovsky equations with zero-range two-body interactions. In particular, we present the correlation between the energies of successive tetramers between two neighbor Efimov trimers and compare it to recent finite range potential model calculations. We provide further results on the large momentum structure of the tetramer wave function, where the four-body scale, introduced in the regularization procedure of the bound state equations in momentum space, is clearly manifested. The results we are presenting confirm a previous conjecture on a four-body scaling behavior, which is independent of the three-body one. We show that the correlation between the positions of two successive resonant four-boson recombination peaks are consistent with recent data, as well as with recent calculations close to the unitary limit. Systematic deviations suggest the relevance of range corrections. 相似文献
106.
N. Tazimi M. Monemzadeh M. R. Hadizadeh 《International Journal of Theoretical Physics》2012,51(9):2871-2877
Quark masses are of great prominence in high-energy physics. In this paper, we have studied the heavy meson systems via solving the Lippmann-Schwinger equation by using the Martin potential for heavy quark masses. We have also attempted to use Martin potential to find an acceptable mass spectrum for heavy quarkonia. We obtained this spectrum via minimal phenomenological model (Melles in Phys. Rev. D. 62:074019, 2000). 相似文献
107.
The polymeric form of lead(II) thenoyltrifluoroacetonate, [Pb(ttfa)2], is modified by adduct formation with 2,2′‐bipyridine (bipy) and 1,10‐phenanthroline (phen) to give, in both cases, dimeric species [Pb2(bipy)2(ttfa)4] and [Pb2(phen)2(ttfa)4], respectively. Crystal structure determinations indicate that labile interactions involving the fluorine atoms and both the thenoyl and aza‐aromatic moieties may be important in determining the lattice arrays of these dimers, which are very similar, even though the dominant lattice forces may differ. 相似文献
108.
[Pb(phe)2]n ( 1 ) (phe is the abbreviation ofphenylalanine) have been synthesized and characterized by elemental analyses, IR and 1H NMR spectroscopy. The single crystal structure of 1 show the complex to be a 2D chain polymer as a result of phenylalanine bridging. Coordination number of PbII ions is six, PbN2O4, with “stereo‐chemically active” electron lone pairs, and the coordination sphere is hemidirected. To the best of our knowledge, this 2D coordination polymer is the first amino acid lead(II) complex that characterized by X‐ray structural analysis. 相似文献
109.
M. Hadi Hadizadeh Yazdi 《Synchrotron Radiation News》2013,26(6):13-14
The 2005 CHESS User Meeting was held on June 14 and 15, 2005, on the campus of Cornell University. A single session occupied the first day, with two concurrent workshops on the second day. The meeting was opened by User Committee member Rob Thorne (Cornell University). CHESS director Sol Gruner began with an overview of the achievements of the most recent running period and the status of the Energy Recovery Linac (ERL), Cornell’s next-generation X-ray photon source project. Quan Hao and Arthur Woll reported on the progress of the Macromolecular Diffraction Facility (MacCHESS) and the G-line, respectively. Don Bilderback gave an account of some of the recent instrumentation developments at CHESS. 相似文献
110.
Farzin Marandi Keyvan Moeini Harald Krautscheid 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(10):1389-1397
Two complexes of 5‐phenyl‐3‐(pyridin‐2‐yl)‐1,2,4‐triazine (PPTA), namely (ethanol‐κO)bis(nitrato‐κO)[5‐phenyl‐3‐(pyridin‐2‐yl‐κN)‐1,2,4‐triazine‐κN2]copper(II), [Cu(NO3)2(C14H10N4)(C2H6O)] or [Cu(NO3)2(PPTA)(EtOH)] ( 1 ), and bis[μ‐5‐phenyl‐3‐(pyridin‐2‐yl)‐1,2,4‐triazine]‐κ3N1:N2,N3;κ3N2,N3:N1‐bis[(nitrato‐κO)silver(I)], [Ag2(NO3)2(C14H10N4)2] or [Ag2(NO3)2(μ‐PPTA)2] ( 2 ), were prepared and characterized by elemental analysis, FT–IR spectroscopy and single‐crystal X‐ray diffraction. The X‐ray structure analysis of 1 revealed a copper complex with square‐pyramdial geometry containing two O‐donor nitrate ligands along with an N,N′‐donor PPTA ligand and one O‐donor ethanol ligand. In the binuclear structure of 2 , formed by the bridging of two PPTA ligands, each Ag atom has an AgN3O environment and square‐planar geometry. In addition to the four dative interactions, each Ag atom interacts with two O atoms of two nitrate ligands on adjacent complexes to complete a pseudo‐octahedral geometry. Density functional theory (DFT) calculations revealed that the geometry around the Cu and Ag atoms in 1 opt and 2 opt (opt is optimized) for an isolated molecule is the same as the experimental results. In 1 , O—H…O hydrogen bonds form R12(4) motifs. In the crystal network of the complexes, in addition to the hydrogen bonds, there are π–π stacking interactions between the aromatic rings (phenyl, pyridine and triazine) of the ligands on adjacent complexes. The ability of the ligand and complexes 1 and 2 to interact with ten selected biomacromolecules (BRAF kinase, CatB, DNA gyrase, HDAC7, rHA, RNR, TrxR, TS, Top II and B‐DNA) was investigated by docking studies. The results show that the studied compounds can interact with proteins better than doxorubicin (except for TrxR and Top II). 相似文献