Orientation-controlled,low-temperature plasma growth and applications of h-BN nanosheets

Nano Research - Dimensionality and orientation of hexagonal boron nitride (h-BN) nanosheets are promising to create and control their unique properties for diverse applications. However,...     

Preparation of gold/hydroxyapatite hybrids using natural fish scale template and their effective albumin interactions

The gold (Au) nanoparticles (NPs) with the diameter of 15–40?nm were successfully synthesized in the hierarchical hydroxyapatite (HAp) nanostructures of natural fish scale templates, which were carried out by the Au³⁺ ion chemisorption, reduction and calcination processes to form the AuNPs/HAp hybrids. The AuNPs size as well as the surface plasmon resonance (SPR) absorption maximum was preserved with the hybridization process. Moreover, the AuNPs/HAp hybrid nanostructures exhibited preferential protein adsorption behavior at the biological bovine serum albumin (Ab) concentration regions that correspond to be 1.5?μM in the cell culture medium and 15.1?μM in human blood, and the Ab adsorption equilibrium constant of AuNPs/HAp hybrid was higher than that of the HAp alone. The SPR absorption maxima of the Ab-adsorbed AuNPs/HAp fish scales were red-shifted as compared with those of the AuNPs/HAp fish scales. Therefore, we synthesized the AuNPs using the fish scale template to exhibit the preferential protein adsorption, which will be a great significance to research the AuNPs/HAp hybrid functions.     

Effect of the Atomic Ratio of Ba to Ti on Optical Properties of Gold-Dispersed BaTiO3 Thin Films

Gold-dispersed BaTiO, thin films were prepared by the rf magnetron sputtering method. The atomic ratio of Ba to Ti in the films was varied and the effects on the linear and nonlinear optical properties were investigated. As the atomic ratio increased, the value of χ⁽³⁾/α₅₃₂ for the gold-dispersed BaTiO₃ thin films slightly increased. It was found that the increase in the value of χ⁽³⁾/α₅₃₂ is due mainly to a change in the crystalline state of the BaTiO₃ matrix. However, it was also found that the atomic ratio had a smaller effect on the value of χ⁽³⁾/α₅₃₂ than did the refractive index of the matrix.     

A new approach to catalytic coal gasification: The recovery and reuse of calcium using biomass derived crude vinegars

A new concept in catalytic coal gasification has been developed. The use of crude vinegars (CVs) derived from different lignocellulosic biomass resources is described for the recovery and reuse of calcium in coal gasification. Calcium introduced by impregnation with a CV solution produced a higher catalytic activity than calcium loaded by impregnation with an aqueous acetic acid solution. Furthermore, CVs were found to be capable of reclaiming calcium from gasification residue and of improving the catalytic activity of the indigenous crystalline calcite in bituminous coal as in situ catalyst.     

Calcium loading during the dewatering of wet biomass in kerosene and catalytic activity for subsequent char gasification

This paper describes a novel approach for upgrading biomass fuels with high water content for gasification, using an oil-slurry dewatering (OSD) process and wet coffee grounds (CG) as a feedstock. The point of novelty is that calcium loading is carried out during the dewatering of wet CG in kerosene. The present work is focused on characterizing the dispersion state of calcium and its catalytic activity for subsequent char gasification. XRD and CO₂ chemisorption techniques have been applied to access the crystallite characteristics of calcium species in OSD-upgraded CG samples and their derived chars. The results obtained show that, for calcium loadings lower than 3 wt%, calcium highly disperses into the CG matrix under dewatering condition, and its catalytic activity for char gasification is comparable to that obtained by impregnation with an aqueous solution of calcium acetate. The results conclude that the dewatering process can provide an effective and practical catalyst loading procedure for biomass fuels with high water content. On the other hand, calcium loadings higher than 3 wt% give raise to poor dispersion in terms of significant decrease in the external surface area of the catalyst, being no longer proportional to the catalytic activity for char gasification.     

Efficient Catalytic Asymmetric Synthesis of trans‐5‐Aryl‐2‐substituted Cyclohexanones by Rhodium‐Catalyzed Conjugate Arylation of Racemic 6‐Substituted Cyclohexenones

Catalytic asymmetric conjugate arylation of racemic 6‐substituted cyclohexenones with arylboronic acids was catalyzed by 3 mol % of chiral amidophosphane‐[RhCl(C₂H₄)]₂ in a 10:1 mixture of 1,4‐dioxane and water at 70 °C to afford a nearly 1:1 mixture of trans‐ and cis‐5‐aryl‐2‐substituted cyclohexanones in high enantioselectivity, which was subsequently epimerized with sodium ethoxide in ethanol to give thermodynamically stable trans‐5‐aryl‐2‐substituted cyclohexanones with 99–97 % ee in high two‐step yields.     

A new approach to phoneme recognition by phoneme filter neural networks

This paper describes a phoneme filter neural network (PFN) approach to phoneme recognition. Most conventional speech recognition neural networks have a serious drawback: the network output values do not correspond to candidate likelihoods. The PFN is a multilayer neural network with fewer hidden units than input units prepared for each of the phoneme categories. Each network is trained as an identity mapping by speech data belonging to one phoneme category. In the recognition process, the similarity between the input data and output data is computed for each network. The results of the experiment to apply the Japanese vowel recognition task showed that the PFN recognition rates for the top two or more choices are higher than those of a conventional three-layer neural network and the PFN outputs represented candidate likelihoods. It was also confirmed that the PFN had a mapping ability and recognition performance superior to those of the linear K-L transformation method because of the nonlinearity of the PFN.     

Robust stability of large-scale systems which contain time-invariant lur'e-type uncertainties in subsystems and norm-bounded uncertainties in interconnections

In this paper a new frequency-domain condition for the robust stability of a class of large-scale systems is derived. It is assumed that each subsystem contains one time-invariant nonlinearity satisfying a sector condition, and that the interconnecting functions are linearly bounded by the norms of the scalar outputs of subsystems. In deriving the above such Lur'e-type Lyapunov functions of subsystems are constructed so that their weighted sum is a Lyapunov function of the overall system. This condition is potential to give a sharper result than the circle-condition-type result which was obtained previously. Furthermore, a method to estimate the domain of attraction using the above Lyapunov function is also given when the sector condition is satisfied only locally.