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11.
O. Aytekin A. Bayri 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2012,86(13):2037-2040
In this study the role of the antiferromagnetic interactions in recently synthesized dinuclear Cr(III) complex has been investigated. Since there was not enough structural information for the characterization of the synthesis, we claim that there should be antiferromagnetic interactions between the dinuclear Fe(III) ions, if the proposed structure is the real structure. A new experiment is proposed to test the predictions of this theoretical investigation. 相似文献
12.
The bat head-related transfer function reveals binaural cues for sound localization in azimuth and elevation 总被引:3,自引:0,他引:3
Aytekin M Grassi E Sahota M Moss CF 《The Journal of the Acoustical Society of America》2004,116(6):3594-3605
Directional properties of the sound transformation at the ear of four intact echolocating bats, Eptesicus fuscus, were investigated via measurements of the head-related transfer function (HRTF). Contributions of external ear structures to directional features of the transfer functions were examined by remeasuring the HRTF in the absence of the pinna and tragus. The investigation mainly focused on the interactions between the spatial and the spectral features in the bat HRTF. The pinna provides gain and shapes these features over a large frequency band (20-90 kHz), and the tragus contributes gain and directionality at the high frequencies (60 to 90 kHz). Analysis of the spatial and spectral characteristics of the bat HRTF reveals that both interaural level differences (ILD) and monaural spectral features are subject to changes in sound source azimuth and elevation. Consequently, localization cues for horizontal and vertical components of the sound source location interact. Availability of multiple cues about sound source azimuth and elevation should enhance information to support reliable sound localization. These findings stress the importance of the acoustic information received at the two ears for sound localization of sonar target position in both azimuth and elevation. 相似文献
13.
We study the relationship of two incidence geometric convexity notions, namely, ovoids in real affine spaces and compact unitals of codimension 1 in topological affine translation planes. In [3] we showed that every ovoid in a translation plane is a unital, and we asked if the converse is true. Here we introduce the notion of a shell, which is distinctly weaker than that of an ovoid and still implies the unital property if the translation plane is properly chosen (and the shell is not too degenerate). We give an explicit example of a shell that is not an ovoid. The question remains whether or not conversely, every compact unital of codimension 1 in a translation plane is a shell.This paper was written while the third author was supported by a grant from DFG and TÜBITAK.Received March 12, 2002
Published online November 18, 2002 相似文献
14.
A spread of
is a set of l-dimensional subspaces L V partitioning V {0}. We construct examples of compact spreads that are identical with their sets of orthogonal spaces L
. In the corresponding topological translation planes, every Euclidean sphere is a unital with the additional property that every point at infinity has flat feet. 相似文献
15.
Nadeem ur Rehman Öznur Gölbaşı Emine Koç 《Rendiconti del Circolo Matematico di Palermo》1938,62(2):245-251
Let \((R,*)\) be a \(2\)-torsion free \(*\)-prime ring with involution \(*\), \(L\ne \{0\}\) be a \(*\)-Lie ideal of \(R\). An additive mapping \(d:R\rightarrow R\) is called an \((\alpha ,\beta )\)-derivation of \(R\) such that \(d(xy)=d(x)\alpha (y)+\beta (x)d(y)\). In the present paper, we shall show that when \(L\) satisfies any of several identities involving \(d\), then \(L\) is central. 相似文献
16.
Emine Özge Karaca Mitat Akkoç Muhammad Nawaz Tahir Cengiz Arıcı Fatma İmik Nevin Gürbüz Sedat Yaşar İsmail Özdemir 《Tetrahedron letters》2017,58(36):3529-3532
A series of seven-membered ditopic ring-expanded N-heterocyclic carbene (dre-NHC) precursors, bearing sterically demanding and electron-rich aryl groups, were synthesised in moderate yields via the reaction of 1,2,4,5-tetrakis(bromomethyl)benzene with the corresponding N,N′-diarylformamidines in the presence of K2CO3 in acetonitrile under an air atmosphere. All new compounds were characterised by HRMS, NMR spectroscopy, and microanalysis, as well as X-ray crystallography for compound 1c. The development of an efficient catalytic system for the Suzuki-Miyaura coupling reaction of aryl chlorides with various boronic acids was also investigated using the in situ generated dre-NHC ligands. 相似文献
17.
Electrochemical behavior of resazurin on HMDE in Britton-Robinson (B-R) buffers (pH 2.0–10.0) was studied using the square-wave
voltammetry (SWV), square-wave adsorptive stripping voltammetry (SWAdSV), and cyclic voltammetry (CV) techniques. The voltammogram
of resazurin in B-R buffer at pH < 4.0 exhibited two cathodic reduction peaks. The voltammetric peaks were obtained at −0.144
V (reversible) and −1.250 V (irreversible) at pH 3.2, and correspond to the reduction of resorufin to dihydroresorufin and
to the catalytic hydrogen wave, respectively. At pH > 4.0, a new irreversible cathodic reduction peak, assigned to the protonation
of N-oxide on the phenoxazin ring, was observed. Electrochemical parameters (I
p/E
p, I
p/v, I
p/pH, I
p/t
acc) of the compound were determined. From the voltammetric data, electrochemical reduction mechanisms for all peaks have been
suggested. Maximum peak current for the reversible peak was obtained at pH 4.1. A linear relationship between the current
and concentration was determined, and also the lowest detection limit was found as 3.25 × 10−8 mol L−1 and 1.98 × 10−10 mol L−1 for SWV and SWAdSV, respectively. 相似文献
18.
Emine Sarigllü 《商业与工业应用随机模型》1994,10(1):27-46
Prediction of customer choice behaviour has been a big challenge for marketing researchers. They have adopted various models to represent customers purchase patterns. Some researchers considered simple zero–order models. Others proposed higher–order models to represent explicitly customers tendency to seek [variety] or [reinforcement] as they make repetitive choices. Nevertheless, the question [Which model has the highest probability of representing some future data?] still prevails. The objective of this paper is to address this question. We assess the predictive effectiveness of the well–known customer choice models. In particular, we compare the predictive ability of the [dynamic attribute satiation] (DAS) model due to McAlister (Journal of Consumer Research, 91, pp. 141–150, 1982) with that of the well–known stochastic variety seeking and reinforcement behaviour models. We found that the stochastic [beta binomial] model has the best predictive effectiveness on both simulated and real purchase data. Using simulations, we also assessed the effectiveness of the stochastic models in representing various complex choice processes generated by the DAS. The beta binomial model mimicked the DAS processes the best. In this research we also propose, for the first time, a stochastic choice rule for the DAS model. 相似文献
19.
20.
Cemal Özeroğlu Emine Doğan Gönül Keçeli 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(2):577-586
In this study, a crosslinked copolymer bearing sodium methacrylate functional groups has been proposed to remove Cs(I) ions
from aqueous solutions. For this purpose, the crosslinked copolymer of ethylene glycol dimethacrylate (EGDM) and methacrylic
acid (MA) containing 25% MA as weight percentage was synthesized by using benzoyl peroxide (BPO)-N,N-dimethyl aniline initiator system. The available carboxyl groups in copolymer were converted to the groups of sodium methacrylate
using 2 N NaOH. The adsorption behavior of cesium ions on the densely crosslinked poly(sodium methacrylate) from aqueous solutions
were investigated by the technique of ICP-MS measurements of cesium ions in solutions. Batch adsorption method was used to
analyze the Cs(I) adsorption as a function of parameters such as the amount of adsorbent, contact time, pH of solution, initial
Cs(I) concentration and temperature. The adsorption data were evaluated by the Freundlich, Langmuir and Dubinin–Radushkevich
(D–R) isotherms. The adsorption capacity and free energy change were calculated by using D–R isotherm. The adsorption data
obtained from experimental results have been tested by the fractional power, the Elovich, the pseudo-first order and the pseudo-second
order kinetic models. 相似文献