Synthesis and electronic, magnetic properties of low-dimensional organometallic reduced mesoporous niobium oxide composites.

Herein I report the synthesis of a new family of organometallic reduced mesoporous niobium oxide composites with mixed oxidation-state organometallic nanowires in the pores and investigate their electronic and magnetic properties. This is a wonderful system which allows us to systematically study one-dimensional molecular metals based on the respective organometallic species and the reducible mesoporous niobium oxide structure. Investigations were conducted on the effects of electron configuration, ionization potential, and electron affinity of organometallic species as well as the composition of mesoporous transition metal oxide walls on the electronic and magnetic properties in the composites and the loading level of organometallics. Results obtained in this work showed the treatment of mesoporous niobium oxide with bis(benzene)chromium, bis(benzene)vanadium, bis(cyclopentadienyl)vanadium, bis(cyclopentadienyl)chromium or decamethylsamarocene led to semiconducting materials with mixed oxidation-state organometallic phases in the pores. The conductivity was as high as 10-4 ohm-1cm -1. The mixed oxidation-state organometallic phase was found playing a main role on the conductivity which was attributed to the oxidation-induced molecular orbital holes in the organometallic phase. The Hubbard model was successfully applied to this new family of materials in an effort to understand the origin of conductivity. Materials in this work were characterized by a combination of techniques including XRD, nitrogen adsorption, EPR spectroscopy, XPS, SQUID magnetometry, room temperature DC conductivity measurements, NMR, and elemental analysis.Dept. of Chemistry and Biochemistry. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2002 .H45. Source: Masters Abstracts International, Volume: 41-04, page: 1080. Adviser: David Antonelli. Thesis (M.Sc.)--University of Windsor (Canada), 2002

SIMD based multicore processor for image and video processing

制度:新 ; 報告番号:甲3602号 ; 学位の種類:博士(工学) ; 授与年月日:2012/3/15 ; 早大学位記番号:新595

Constraining Astrophysical Neutrino Flavor Composition from Leptonic Unitarity

The recent IceCube observation of ultra-high-energy astrophysical neutrinos has begun the era of neutrino astronomy. In this work, using the unitarity of leptonic mixing matrix, we derive nontrivial unitarity constraints on the flavor composition of astrophysical neutrinos detected by IceCube. Applying leptonic unitarity triangles, we deduce these unitarity bounds from geometrical conditions, such as triangular inequalities. These new bounds generally hold for three flavor neutrinos, and are independent of any experimental input or the pattern of leptonic mixing. We apply our unitarity bounds to derive general constraints on the flavor compositions for three types of astrophysical neutrino sources (and their general mixture), and compare them with the IceCube measurements. Furthermore, we prove that for any sources without $\nu_\tau$ neutrinos, a detected $\nu_\mu$ flux ratio $< 1/4$ will require the initial flavor composition with more $\nu_e$ neutrinos than $\nu_\mu$ neutrinos.Comment: JCAP Final Version. 24pp. Only minor refinements, references adde

Cue validity and object-based attention

In a previous study, Egly, Driver, and Rafal (1994) observed both space- and object-based components of visual selective attention. However, the mechanisms underlying these two components and the relationship between them are not well understood. In the present research, with a similar paradigm, these issues were addressed by manipulating cue validity. Behavioral results indicated the presence of both space- and object-based components under high cue validity, similar to the results of Egly et al.'s study. In addition, under low cue validity, the space-based component was absent, whereas the object-based component was maintained. Further event-related potential results demonstrated an object-based effect at a sensory level over the posterior areas of brain, and a space-based effect over the anterior region. The present data suggest that the space- and object-based components reflect mainly voluntary and reflexive mechanisms, respectively

Origin of Constrained Maximal CP Violation in Flavor Symmetry

Current data from neutrino oscillation experiments are in good agreement with $\delta =-\frac{\pi}{2}$ and $\theta_{23}^{} = \frac{\pi}{4}$. We define the notion of "constrained maximal CP violation" (CMCPV) for predicting these features and study their origin in flavor symmetry. We derive the parametrization-independent solution of CMCPV and give a set of equivalent definitions for it. We further present a theorem on how the CMCPV can be realized. This theorem takes advantage of residual symmetries in the neutrino and charged lepton mass matrices, and states that, up to a few minor exceptions, $(|\delta |, \theta_{23}) =(\frac{\pi}{2}, \frac{\pi}{4})$ is generated when those symmetries are real. The often considered $\mu$-$\tau$ reflection symmetry, as well as specific discrete subgroups of O(3), are special cases of our theorem.Comment: Phys.Lett.B Final Version, 13pp. All conclusions unchanged, only minor improvement to stress the parametrization-independence of our CMCP

Individualism-collectivism and interpersonal memory guidance of attention

Recently it has been shown that the allocation of attention by a participant in a visual search task can be affected by memory items that have to be maintained by a co-actor, when similar tasks are jointly engaged by dyads (He, Lever, & Humphreys, 2011). In the present study we examined the contribution of individualism-collectivism to this ‘interpersonal memory guidance’ effect. Actors performed visual search while a preview image was either held by the critical participant, held by a co-actor or was irrelevant to either participant. Attention during search was attracted to stimuli that matched the contents of the co-actor’s memory. This interpersonal effect correlated with the collectivism scores, and was enhanced by priming with a collectivistic scenario. The dimensions of individualism, however, did not contribute to performance. These data suggest that collectivism, but not individualism, modulates interpersonal influences on memory and attention in joint action