Materials Literature
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We use ab initio calculations to examine thermodynamic factors that could promote the formation of recently proposed unique oP10-FeB4 and oP12-FeB2 compounds. We demonstrate that these compact boron-rich phases are stabilized further under pressure. We also show that chromium tetraboride is more stable in the new oP10…
We study the vibrational spectrum and the low energy modes of a three dimensional colloidal crystal using confocal microscopy. This is done in a two-dimensional cut through a three-dimensional crystal. We find that the observed density of states is incompatible with the standard Debye form in either two or three dimen…
We present a theoretical analysis of the nonlinear response of a metamaterial consisting of an array of split ring resonators coupled to a two level atomic system (2LS) without inversion. We calculated the total complex susceptibility and the linear, third and fifth-order nonlinear solution of the Maxwell Bloch equati…
High resolution neutron diffraction has been used to investigate the structural origin of the large electric-field-induced remanent strain in 94(Bi1/2Na1/2)TiO3–6BaTiO3 ceramics. The virgin material was found to be a mixture of near-cubic phases with slight tetragonal and rhombohedral distortions of a0a0c+ and a−a−a−…
Silicene nanoribbons grown on a silver (110) substrate have been studied by reflection electron energy loss spectroscopy as a function of the electron beam incidence angle α. The spectra, taken at the Si K absorption edge (1.840 keV), reveal the presence of two distinct loss structures attributed to transitions 1s→π∗…
Graphene has attracted growing interest in the past few years. Growing vertically oriented graphene sheets with a designed pattern is practically attractive for device applications based on graphene. Here we report a patterned synthesis of vertical graphene nanosheets using plasma-enhanced chemical vapor deposition. B…
An environmentally benign approach to impart stainless steel (SS) surfaces with antifouling and antibacterial functionalities was described. Surface-initiated atom transfer radical polymerization (ATRP) of poly(ethylene glycol) monomethacrylate) (PEGMA) from the SS surface-coupled catecholic L-3,4-dihydroxyphenylalani…
A polymer-stabilized blue phase liquid crystal (BPLC) composite with a large Kerr constant (K∼13.7 nm/V2) is developed and its electro-optic properties characterized. In addition to the reduced operating voltage, this BPLC also exhibits a fast response time (∼1 ms), high contrast ratio (>1000:1), and relatively…
Yttrium phosphates codoped (Ce 3+,Ln 3+ ) and (Pr 3+,Ln 3+ ) with Ln = Nd, Er, Ho, Dy were investigated by thermally stimulated luminescence. Similar to Ce 3+, Pr 3+ was found able to trap holes up to high temperatures while being the radiative recombination center, whereas the Ln 3+ codopant played the role of the el…
Thin film assemblies of branched polyethylenimine (PEI) and poly(acrylic acid) (PAA), deposited using the layer-by-layer technique, were studied in an effort to produce all-polymer thin films with low oxygen permeability. Altering the pH of PEI and PAA results in large thickness variations (from 90 nm to 4.74 μm for 3…
Using first-principles calculations, we show that the band gap and electron effective mass (EEM) of graphene/boron nitride heterobilayers (C/BN HBLs) can be modulated effectively by tuning the interlayer spacing and stacking arrangement. The HBLs have smaller EEM than that of graphene bilayers (GBLs), and thus higher…
The negatively charged nitrogen-vacancy centre is a unique defect in diamond that possesses properties highly suited to many applications, including quantum information processing, quantum metrology and biolabelling. Although the unique properties of the centre have been extensively documented and utilized, a detailed…
Abstract NR/GE composites were prepared by an ultrasonically‐assisted latex mixing and in situ reduction process. Graphene oxide was dispersed in NRL using an ultrasonic field and was then reduced in situ, followed by latex coagulation to obtain the NR/GE masterbatch. The results show that the process produces a much…
Pyrophosphate (PPi) is a biologically important target. A binuclear system 3•2Zn is found to selectively recognize PPi, leading to a ratiometric fluorescent sensor at pH 7.4 in water. The binding event triggered a large fluorescence response (∼100 nm bathochromic shift) by turning on the excited state intramolecular p…
We investigate spin-dependent decay and intersystem crossing (ISC) in the optical cycle of single negatively charged nitrogen-vacancy (NV) centres in diamond. We use spin control and pulsed optical excitation to extract both the spin-resolved lifetimes of the excited states and the degree of optically induced spin pol…
The electrical property of graphene is highly sensitive to its local environment, which makes graphene an ideal channel material in electronic sensors. Reduced graphene oxide (rGO) has been used as the desirable alternative to the pristine graphene due to its low-cost, solution-processable, and scalable production. In…
We introduce a process for the fabrication of high-quality, spatially isolated nano-diamonds on iridium via microwave-plasma-assisted chemical vapour deposition (CVD) growth. We perform spectroscopy of single silicon-vacancy (SiV) centres produced during the growth of the nano-diamonds. The colour centres exhibit extr…
비닐 아세트산염 합성에 대한 1족 알칼리금속 아세트산염의 촉진 효과를 조사하였다. Pd-Au/<TEX>$SiO_2$</TEX> 촉매를 사용한 경우와 사용하지 않은 경우에 대해 에틸렌과 아세트산 간의 기체상 반응에 대해 생성물 선택성과 에틸렌 전환을 비교하였다. 촉진제가 촉매 표면을 안정화시켰으며, 생성물 선택성과 에틸렌 전환을 촉진하였다. 이 촉매 효과는 1족에서 위에서 아래로 내려갈수록 증가하였다. 이것은 아세트산염의 공통이온효과 때문이다. The effect of Group I alkali acetate promoters on vinyl acetate (VA)…
전자구조의 계산에서 교환과 상관 효과에 대한 기술을 개선하기 위해서는 교환-상관범함수에 대한 개념을 명확히 하는 것이 바람직하다. 이 목적을 성취하기 위해서는 많은 그룹의 물질에 대하여 다른 이론 방법을 적용할 필요가 있다. 본 연구에서는 탄소나노튜브의 고리와 바구니 내원자들의 밀도전하를 연구하기 위하여 혼성 밀도함수 이론(DFT) 계산을 수행하였다. 핵-핵 에너지, 전자-핵 에너지와 운동에너지에 대한 교환 및 상호작용을 관찰하였으며, B3P86, B3PW91, B1B96, BLYP와 B3LYP 수준에서 계산하였다. As an aid towards improving…
Surgeons performing endovascular interventions have high expectations with regard to the improvement of their operating tools and, more specifically, of their catheters. Active catheters, in which the tip moves actively using Shape Memory Alloy (SMA) actuators, constitute a promising approach. In this article, we revi…