Bifurcation analysis of a simple 3D oscillator and chaos synchronization of its coupled systems

Tama?evi?ius et al. proposed a simple 3D chaotic oscillator for educational purpose. In fact the oscillator can be implemented very easily and it shows typical bifurcation scenario so that it is a suitable training object for introductory education for students. However, as far as we know, no concrete studies on bifurcations or applications on this oscillator have been investigated. In this paper, we make a thorough investigation on local bifurcations of periodic solutions in this oscillator by using a shooting method. Based on results of the analysis, we study chaos synchronization phenomena in diffusively coupled oscillators. Both bifurcation sets of periodic solutions and parameter regions of in-phase synchronized solutions are revealed. An experimental laboratory of chaos synchronization is also demonstrated.     

Sperner’s lemma and zero point theorems on a discrete simplex and a discrete simplotope

We show two discrete zero point theorems that are derived from Sperner’s lemma and a Sperner-like theorem (van der Laan and Talman [Math. Oper. Res. (1982)] [5]; Freund [Math. Oper. Res. (1986)]) [3]. Applications to economic and game models are also presented.     

Volume and viscosity of Zr–Cu–Al glass-forming liquid alloys

We examined the volume and viscosity of Zr–Cu–Al glass-forming liquid alloys to clarify the origin of a frozen free volume in glassy alloys. Since an excess free volume imparts toughness and ductility to glassy alloys, we attempted to increase this volume in glass structures so that they could be used as engineering materials. The maximum frozen excess free volume was observed in the ternary eutectic composition of the Zr–Cu–Al alloy system; however, its origin remains unclear. We attempted to reveal the mechanism of the formation of the frozen excess free volume in Zr–Cu–Al glassy alloys.     

Asymmetric Synthesis of Heptacosane-6,8-Diols Induced by Chiral Sulfoxides

The asymmetric synthesis of (6S,8R)-, (6S,8S)-, (6R,8S)- and (6R,8R)-heptacosane-6,8-diols from (2S)-, (2R)-1-[(R)-p-tolylsulfinyl]-2-heptanols and 1-icosanal is described.     

Photothermal Conversion of CO2 into CH4 with H2 over Group VIII Nanocatalysts: An Alternative Approach for Solar Fuel Production

The photothermal conversion of CO₂ provides a straightforward and effective method for the highly efficient production of solar fuels with high solar‐light utilization efficiency. This is due to several crucial features of the Group VIII nanocatalysts, including effective energy utilization over the whole range of the solar spectrum, excellent photothermal performance, and unique activation abilities. Photothermal CO₂ reaction rates (mol h^?1 g^?1) that are several orders of magnitude larger than those obtained with photocatalytic methods (μmol h^?1 g^?1) were thus achieved. It is proposed that the overall water‐based CO₂ conversion process can be achieved by combining light‐driven H₂ production from water and photothermal CO₂ conversion with H₂. More generally, this work suggests that traditional catalysts that are characterized by intense photoabsorption will find new applications in photo‐induced green‐chemistry processes.     

A new confidence interval for all characteristic roots of a covariance matrix

Confidence intervals for all of the characteristic roots of a sample covariance matrix are derived. Using a perturbation expansion, we obtain a new confidence interval for these roots. Then, we propose another confidence interval based on the results of Monte Carlo simulations. Since it is based on simulations, this new confidence interval is both narrower and more accurate than others when the difference between the largest and smallest characteristic roots of the population covariance matrix is large.     

Multistage devitrification of Mg-Ni-Mm and g-Ni-Y-Mm metallic glasses (Mm = misch metal)

Devitrification behaviour of Mg-Ni-Mm and Mg-Ni-Y-Mm metallic glasses (Mm = misch metal) was studied by differential scanning calorimetry, isothermal calorimetry, X-ray diffractometry and transmission electron microscopy. These materials exhibited a multistage devitrification with a primary exothermic peak with an onset temperature of about 450 K. Local atomic order changed during primary devitrification. This change occurs without an incubation period and leads to embrittlement of the samples. The activation energy value for the first exothermic heat effect in the Mg 86 Ni 10 Y 2 Mm 2 alloy is higher than the activation energy for Mg self-diffusion, implying that redistribution of the other alloying elements also takes place. The strongest heat effects are connected with the devitrification of the amorphous phase (changes in the local atomic order, precipitation of hcp Mg and the metastable compounds) while the magnitude of the heat effect of the transformation of metastable crystalline phases to stable phases in the Mg 86 Ni 10 Y 2 Mm 2 alloy, for example, is 17 times weaker than the effect of devitrification of the amorphous phase. A continuous heating transformation diagram is derived from the results.     

G protein subtype specificity of rhodopsin intermediates metarhodopsin Ib and metarhodopsin II

Rhodopsin is one of the members of the G protein-coupled receptor family that can catalyze a GDP–GTP exchange reaction on the retinal G protein transducin (Gt) upon photon absorption. There are at least two intermediate states, meta-Ib and meta-II, which exhibit direct interaction with Gt. Meta-Ib binds to GDP-bound Gt, while meta-II forms a complex with Gt having no nucleotide, suggesting that meta-Ib is a state that initially interacts with Gt. Here we investigated whether or not meta-Ib exhibits specific interaction with G protein similar to meta-II, by examining the binding efficiencies of meta-Ib and meta-II to Giα and its mutants whose C-terminal 11 amino acids were replaced with those of Goα, Gqα and Gsα. The affinity of meta-Ib to the C-terminal 11 amino acids of Gtα was similar to those of Giα and its mutant with Goα's C-terminal 11 amino acids, whereas meta-II exhibited affinity to the C-terminal 11 amino acids of Giα mutant with Goα's C-terminal 11 amino acids about half of what was seen for Gtα and Giα. Both intermediates exhibited no affinity to the Giα mutants containing the C-terminal 11 amino acids of Gqα and Gsα. These results suggested that meta-Ib is the state that exhibits specific interaction with G protein as meta-II does, although meta-Ib exhibits a slightly lenient binding selectivity compared to that of meta-II.