[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

The term photonic crystals appears because of the analogy between electron waves in crystals and the light waves in artificial periodic dielectric structures. During the recent years the investigation of one-, two-and three-dimensional periodic structures has attracted a widespread attention of the world optics community because of great potentiality of such structures in advanced applied optical fields. The interest in periodic structures has been stimulated by the fast development of semiconductor technology that now allows the fabrication of artificial structures, whose period is comparable with the wavelength of light in the visible and infrared ranges.

http://ieeexplore.ieee.org/iel5/6354/16969/00781867.pdf

Photonic crystals

II. Structure of Perovskites 1982 A. Crystal Structure 1982 B. Nonstoichiometry in Perovskites 1983 1. Oxygen Nonstoichiometry 1983 2. Cation Nonstoichiometry 1984 C. Physical Properties 1985 D. Adsorption Properties 1986 1. CO and NO Adsorption 1986 2. Oxygen Adsorption 1987 E. Specific Surface and Porosity 1987 F. Thermal Stability in a Reducing Atmosphere 1989 III. Acid−Base and Redox Properties 1990 A. Acidity and Basicity 1990 B. Redox Processes 1991 1. Kinetics and Mechanisms 1992 2. Reduction−Oxidation Cycles 1993 C. Ion Mobility 1993 1. Oxygen Transport 1993 2. Cation Transport 1994 IV. Heterogeneous Catalysis 1995 A. Oxidation Reactions 1995 1. CO Oxidation 1995 2. Oxidation of Hydrocarbons 1996 B. Pollution Abatement 2001 1. NOx Decomposition 2001 2. Exhaust Treatment 2002 3. Stability 2004 C. Hydrogenation and Hydrogenolysis Reactions 2004 1. Hydrogenation of Carbon Oxides 2004 2. Hydrogenation and Hydrogenolysis Reactions 2006

Chemical structures and performance of perovskite oxides.

Nanoparticles (NPs) are increasingly used to target bacteria as an alternative to antibiotics. Nanotechnology may be particularly advantageous in treating bacterial infections. Examples include the utilization of NPs in antibacterial coatings for implantable devices and medicinal materials to prevent infection and promote wound healing, in antibiotic delivery systems to treat disease, in bacterial detection systems to generate microbial diagnostics, and in antibacterial vaccines to control bacterial infections. The antibacterial mechanisms of NPs are poorly understood, but the currently accepted mechanisms include oxidative stress induction, metal ion release, and non-oxidative mechanisms. The multiple simultaneous mechanisms of action against microbes would require multiple simultaneous gene mutations in the same bacterial cell for antibacterial resistance to develop; therefore, it is difficult for bacterial cells to become resistant to NPs. In this review, we discuss the antibacterial mechanisms of NPs against bacteria and the factors that are involved. The limitations of current research are also discussed.

/pdf/the-antimicrobial-activity-of-nanoparticles-present-455xafgyws.pdf

The antimicrobial activity of nanoparticles: present situation and prospects for the future

Tubular and fibrous nanostructures of titanates have recently been
synthesized and characterized. Three general approaches (template assisted, anodic oxidation, and alkaline hydrothermal) for the preparation of nanostructured titanate and TiO2 are reviewed. The crystal structures, morphologies, and mechanism of formation
of nanostructured titanates produced by the alkaline hydrothermal method are critically discussed. The physicochemical properties of nanostructured titanates are highlighted and the links between properties and applications are emphasized. Examples of early applications of nanostructured titanates in catalysis, photocatalysis, electrocatalysis, lithium batteries, hydrogen storage, and solar-cell technologies are reviewed. The stability of titanate nanotubes at elevated temperatures and in acid media is considered.

Protonated Titanates and TiO2 Nanostructured Materials: Synthesis, Properties, and Applications

The effect of postannealing temperature (500, 600 and 700°C) on the band alignments and interfacial structures of Al2O3 films grown on Ge by atomic layer deposition was investigated by X-ray photoelectron spectroscopy and electrical measurements. With increasing postannealing temperature, the reaction between Al2O3 and Ge becomes serious and the valence-band offsets of Al2O3/Ge interface is observed to upshift. The conduction-band offsets at the interface of Al2O3/Ge without and with postannealing temperatures at 500, 600 and 700°C are estimated to be 2.90, 2.75, 2.59 and 2.41 eV, respectively.

Effects of Postannealing Temperature on the Band Alignments and Interfacial Properties of Atomic Layer Deposited Al2O3 on Ge Substrates

PEMFCs In article number 2103144, Jia Li, Jianguo Liu and co-workers demonstrate the underlying mechanism of cobalt doping on the unprecedented activity and durability of sub-2 nm Pt nanoclusters. With extremely efficient utilization of Pt and superior performance in low-Pt loading proton exchange membrane fuel cells (PEMFCs), the electrocatalysts contribute significantly to reduce the cost of PEMFCs and mitigate the dependence of hydrogen energy on precious metals. 

Cobalt‐Doping Stabilized Active and Durable Sub‐2 nm Pt Nanoclusters for Low‐Pt‐Loading PEMFC Cathode (Adv. Energy Mater. 13/2022)

SrBi2Ta2O9 (SBT) films were prepared on Pt/TiO2/SiO2/Si substrates at 750°C in oxygen by metalorganic decomposition method. SBT film capacitors were re-annealed in Ar (N2) at 350-750°C and then followed the O2 recovery at 750°C. Effects of anneal atmosphere on the structure, morphology and ferroelectric properties have been investigated deeply. After above 550°C 100% Ar or N2 reanneal, the remnant polarization decreases and coercive field increases significantly. The subsequent O2 recovery can hardly rejuvenated them. The result is different from that from forming gas processing (annealing in hydrogen atmosphere). The possible origin and mechanism is discussed and proposed.

Effects of anneal atmosphere on the structural and ferroelectric properties of SrBi2Ta2O9 thin films

SrBi 2 Ta 2 O 9 (SBT) films were prepared on Pt/TiO 2 /SiO 2 /Si and P-Si(100) substrates by metal-organic decomposition. Electric field was in-situ applied on the films during crystallization. It was found that magnitude and direction of the field and the substrate had great effect on structure, morphology and ferroelectric properties of the SBT films. Positive field (assuming the substrates is electrical grounded) enhanced C-axis orientation of the films deposition on Pt/TiO 2 /SiO 2 /Si substrates, while negative field had little effect on it. Meanwhile electric field had no effect on that of the films deposited on Si substrates. The films deposited on Pt/TiO 2 /SiO 2 /Si substrates under 90 V and 120 V applied voltage had good fatigue and retention properties. We think that amount and kind of induced charge in the interface between the film and substrate are main causes of the structure change.

Aidong Li

Papers

Effects of Postannealing Temperature on the Band Alignments and Interfacial Properties of Atomic Layer Deposited Al2O3 on Ge Substrates

Cobalt‐Doping Stabilized Active and Durable Sub‐2 nm Pt Nanoclusters for Low‐Pt‐Loading PEMFC Cathode (Adv. Energy Mater. 13/2022)

Effects of anneal atmosphere on the structural and ferroelectric properties of SrBi2Ta2O9 thin films

Effect of In-Situ Applied Electric Field on Structure and Ferroelectric Properties of SrBi 2 Ta 2 O 9 Films

Ferroelectric SrBi2Ta2O9-SiO2 Glass-Ceramic Thin Films in Metal/Ferroelectric/Insulator/Semiconductor Structures