[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

Well-crystallized Nd-substituted Bi4Ti3O12 ferroelectric thin films, Bi3.5Nd0.5Ti3O12 (BNdT50) and Bi3.15Nd0.85Ti3O12 (BNdT85), were prepared on Pt/TiO2/SiO2/Si substrates by chemical solution deposition. The microstructures were studied by x-ray diffraction and transmission electron microscopy. Fatigue characteristics of BNdT50 and BNdT85 films were measured at 25, 75 and 125 °C. Both films showed better fatigue resistance at elevated temperatures. The improved fatigue resistance is discussed in terms of the temperature dependence of the competition between domain wall pinning and unpinning, which determine the loss of remanent polarization.

https://iopscience.iop.org/article/10.1088/0022-3727/41/12/122003/pdf

Fatigue characteristics of Nd-substituted Bi4Ti3O12 ferroelectric thin films at elevated temperatures

Fabrication of fine mullite powders by α-Al(OH)3–SiO2 core–shell structure precursors

In this work, zinc sulfide (ZnS) on hydroxylated multi-walled carbon nanotubes (MWCNTs) composite was prepared for lithium-ion batteries (LIBs) anode. It is demonstrated that atomic layer deposition (ALD) enables a conformal, uniform, and ultrathin ZnS (~ 7 nm) layer onto the surface of hydroxylated MWCNTs. The resulting MWCNTs@ZnS core–shell composite displays excellent electrochemical performances as LIBs anode, accounting for high capacity, stable cyclability, high rate capability, and exceptional coulombic efficiency. The MWCNTs@ZnS composite can exhibit a stable discharge capacity, sustaining 520 mAh g−1 versus 108 mAh g−1 for commercial ZnS powders after 200 cycles at 100 mA g−1. The improved electrochemical performances are attributed to the synergistic effect from MWCNTs and ALD ZnS film. MWCNTs have good conductivity and huge surface area while the ALD ZnS film has high Li storage capability. This study verifies that ALD is highly flexible in developing excellent electrodes of LIBs.

Core-shell MWCNTs@ZnS composite prepared by atomic layer deposition for high-performance lithium-ion batteries anode

A stretchable petal patterned strain sensor comprising Ir nanoparticles-modified multi-walled carbon nanotubes for human-motion detection

Hydrophilic FePt nanoparticles (NPs) have been embedded into the MgO-matrix systems via a sol–gel process to prevent FePt NPs from aggregating and sintering during the heat-treatment process required for the L10 ordering. The chemically ordered L10-phase FePt can be obtained after annealing at 700 °C for 60 min in atmosphere containing H2. The effect of the pH value of MgO collosol and FePt nanocrystal loading amount on the structure, morphology, and magnetic properties of FePt/MgO nanocomposites has been investigated. The neutral pH value of 7 in MgO sol is beneficial to stabilize FePt NPs and obtain higher chemical ordering parameter S for the face-centered tetragonal -FePt/MgO nanocomposites with larger coercivity. The FePt NPs loading amount also plays a key role in tuning the microstructure and magnetic properties of the nanocomposites. The relatively higher FePt NPs loading with FePt/MgO molar ratio (RFM) of 1:2 leads to relatively perfect hexagonal assembly and pure L10 phase. When the RFM is 1:5 and 1:10, the MgO-matrix in nanocomposites causes the Fe element loss in FePt NPs along with formation of secondary phases such as magnesioferrite or Pt3Fe during the annealing process. Under optimal processing of neutral pH value of 7 and RFM of 1:2, the presence of MgO matrix produces more homogeneous microstructures and better magnetic properties with higher room-temperature coercivity (H
 C = 4.65 kOe).

Aidong Li

Papers

Fatigue characteristics of Nd-substituted Bi4Ti3O12 ferroelectric thin films at elevated temperatures

Fabrication of fine mullite powders by α-Al(OH)3–SiO2 core–shell structure precursors

Core-shell MWCNTs@ZnS composite prepared by atomic layer deposition for high-performance lithium-ion batteries anode

A stretchable petal patterned strain sensor comprising Ir nanoparticles-modified multi-walled carbon nanotubes for human-motion detection

Fabrication and magnetic properties of FePt nanoparticle assemblies embedded in MgO-matrix systems