Band Gaps of Na2C60 and K4C60

respectively.     

Sillimanite‐mullite transformation observed in synchrotron X‐ray diffraction experiments

High‐resolution synchrotron powder X‐ray diffraction (XRD) experiments were conducted to clarify the transformation of sillimanite to mullite (mullitization) and determine the mullitization temperature (T_c). We were able to distinguish sillimanite and mullite in the XRD patterns, despite their very similar crystallographic parameters, and to detect the appearance of small mullite peaks among sillimanite peaks. Analysis of the Johnson‐Mehl‐Avrami (JMA) equation for mullitization ratio (ζ) revealed that at temperatures T≥1240°C the mullitization had the same kinetics. The activation energy E at T≥1240°C obtained from the Arrhenius plot was 679.8 kJ mol^?1. In analysis using a time‐temperature‐transformation diagram for mullitization, a mullitization curve of ζ=1% can be described as where t is time, n is a reaction‐mechanism‐dependent parameter determined as 0.324 by JMA‐analysis, k₀ is the frequency factor, E_A is the activation energy for atomic diffusion, and represents the activation energy for nucleation. The results of fitting the data to this equation were T_c=1199°C, A=3.9×10⁶ kJ mol^?1 K^?2, E_A=605 kJ mol^?1, and k₀=3.65×10¹⁵. We conclude that the boundary between sillimanite and mullite+SiO₂ in the phase diagram is ~1200°C.     

In Situ Observation of Deformation in Semi-solid Fe-C Alloys at High Shear Rate

Synchrotron X-ray radiography at 125 frames per second was used to study deformation mechanisms in semi-solid Fe-C alloys at high solid fraction and shear strain rates of 10^?1/s. An image correlation approach was also used to quantify the shear strain fields and study shear-induced dilation and the origin of shear cracking. It was shown that, at high solid fraction (90 to 93 pct solid), rearrangement including rotation and translation of solid particles became restricted and shear strain localized into narrow liquid-filled channels/fissures. Shear cracking was shown to originate from inadequate liquid flow into the expanding spaces between solid particles caused by shear-induced dilation. At lower solid fraction (~85 pct solid), solid particles rearranged with a significantly higher component of rotation leading to more shear-induced dilation and a wider shear band.     

Ground object recognition and segmentation from aerial image‐based 3D point cloud

Several attempts have been made to grasp three‐dimensional (3D) ground shape from a 3D point cloud generated by aerial vehicles, which help fast situation recognition. However, identifying such objects on the ground from a 3D point cloud, which consists of 3D coordinates and color information, is not straightforward due to the gap between the low‐level point information (coordinates and colors) and high‐level context information (objects). In this paper, we propose a ground object recognition and segmentation method from a geo‐referenced point cloud. Basically, we rely on some existing tools to generate such a point cloud from aerial images, and our method tries to give semantics to each set of clustered points. In our method, firstly, such points that correspond to the ground surface are removed using the elevation data from the Geographical Survey Institute. Next, we apply an interpoint distance‐based clustering and color‐based clustering. Then, such clusters that share some regions are merged to correctly identify a cluster that corresponds to a single object. We have evaluated our method in several experiments in real fields. We have confirmed that our method can remove the ground surface within 20 cm error and can recognize most of the objects.     

Investigation into Coordination States of Diglycolamide and Dioxaoctanediamide Complexes with Lanthanide Elements Using Spectroscopic Methods

The extraction behavior and complexation state of diglycolamide (DGA) and dioxaoctanediamide (DOODA) ligands were investigated for several trivalent lanthanide ions (Ln(III)). The stoichiometry of the extraction of La(III), Nd(III), and Ho(III) with the hydrophobic ligands, N,N,N’,N’-tetraoctyl diglycolamide (TODGA) and N,N,N’,N’-tetraoctyl dioxaoctanediamide (DOODA(C8)), was determined by slope analyses in CHCl₃ and CCl₄ system. Ultraviolet-visible (UV-Vis) spectroscopy was employed for determination of the stability constants (β) of trivalent lanthanide ion (Ln³⁺) with the hydrophilic ligands, N,N,N’,N’-tetraethyl diglycolamide (TEDGA) and N,N,N’,N’-tetraethyl dioxaoctanediamide (DOODA(C2)). DGA ligands are found to have an affinity of heavier Ln(III), while DOODA ligands prefer to coordinate with lighter Ln(III). Infrared (IR) and nuclear magnetic resonance (NMR) spectroscopic measurements reveal that the carbonyl oxygen atoms of TODGA and DOODA(C8) worked as dominant donors in complexation with La(III). In contrast, the ether oxygen of the hydrophilic ligands makes major contribution to formation of La(III) complex.     

Development of Trityl Group Anchored Solubilizing Tags for Peptide and Protein Synthesis

Recently, solubilizing tag methods (Trt-K and Trt-R method) were developed for the challenging synthesis of peptides/proteins by means of native chemical ligation. In this system, the solubilizing tag can be attached to the Cys side chain by simply mixing the tag-introducing reagent under acidic conditions. The tagged peptides/proteins exhibited high water solubility thanks to the introduction of redundant oligo-Lys/Arg. In the final reaction, the tag can be quickly and cleanly detached by a standard deprotection reaction with trifluoroacetic acid. Herein, the development and application of these methods are described.