We develop a simplified light source at 461 nm for laser cooling of Sr without frequency-doubling crystals but with blue laser diodes. An anti-reflection coated blue laser diode in an external cavity (Littrow) configuration provides an output power of 40 mW at 461 nm. Another blue laser diode is used to amplify the laser power up to 110 mW by injection locking. For frequency stabilization, we demonstrate modulation-free polarization spectroscopy of Sr in a hollow cathode lamp. The simplification of the laser system achieved in this work is of great importance for the construction of transportable optical lattice clocks.

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Macrocyclic compounds consisting of three 2,6-pyridylene and three 3,5-pyridylene units linked by acetylene bonds were synthesized by a Sonogashira reaction. The X-ray structures showed π-stacked pairs of two macrocycles, in which a 2,6-pyridylene unit of the one molecule overlaps a 3,5-pyridylene of the other molecule because of dipole-dipole interaction. Atomic force microscope (AFM) measurements revealed fibril structures indicating the stacking of the rigid planar macrocycles. Hydrogen-bonding ability of the macrocyclic inside was demonstrated by the addition of octyl β-D-glucopyranoside.

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A simple, easy, and rapid process of fabricating superhydrophobic surfaces on magnesium alloy AZ31 by a one-step immersion at room temperature was developed. The myristic acid-modified micro-/nanostructured surfaces showed static water contact angles over 150° and water contact angle hysteresis below 10°, thus illustrating superhydrophobic property. The shortest treatment time for obtaining the superhydrophobic surfaces was 30 s. In addition, we demonstrated for the first time that crystalline solid myristic acid could be formed on a Mg alloy using a suitable molar ratio of Ce ions and myristic acid. The contact angle hysteresis was lowered with an increase in the immersion time. Potentiodynamic polarization curve measurements revealed that the corrosion resistance of AZ31 treated by the immersion process improved considerably by the formation of superhydrophobic surfaces. The chemical durability of the superhydrophobic surfaces fabricated on AZ31 was also examined. The static water contact angle values for the superhydrophobic surfaces after immersion in aqueous solutions at pHs 4, 7, and 10 for 12 h were estimated to be 90 ± 2°, 119 ± 2°, and 138 ± 2°, respectively, demonstrating that their chemical durability in a basic solution was high.

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Transition-metal-doped Li2O cathodes using redox reaction of solid-state oxygen are candidates as high capacity cathode materials for lithium-ion batteries. In our previously reported study, copper-doped Li2O (CuDL) exhibited a high charge–discharge capacity of 300 mAh g–1. However, the developed cathode not only exhibited poor cyclability but also decomposed during charge–discharge cycles. In this study, fluorine and copper were codoped into the Li2O structure by stepwise mechanochemical reaction to create a high performance cathode with high cyclability. Fluorine-, copper-doped Li2O (F–CuDL) was prepared by the mechanochemical reaction of Li2O with LiF, followed by a reaction with CuO. The F–CuDL cathode exhibited a good cycle performance (300 mAh g–1, 30 cycles at a constant current of 50 mA g–1). X-ray diffraction (XRD) and Cu K-edge X-ray absorption near edge structure (XANES) analyses revealed that F–CuDL does not undergo decomposition even after charge–discharge cycles, revealing that doping with fluorine leads to the stabilization of the CuDL crystal structure.

Absolute intensity calibrated extreme ultraviolet spectra radiated by highly charged holmium (Ho) ions from 1 μm Nd:YAG laser generated plasmas in the 1–8 nm wavelength spectral range were measured and investigated. The spectral features show a broad structured continuum-like emission band, most prominent in the wavelength range 6–8 nm, which accounts for more than half of the emitted power. Assuming local thermodynamic equilibrium (LTE) in the laser produced plasmas and using the flexible atomic code and Cowan suite of codes, the wavelengths and LTE-gA values of unresolved transition arrays (UTAs) from E 1-contributing transition arrays 4p–4d, 4d–4f and super transition arrays such as 4p64d k−14f + 4p54d k+1–4p64d k−24f2 + 4p44d k+2 + 4p54d k 4f and 4d10(5s5p) k 4f m−k –4d9(5s5p) k 4f m−k+1 were calculated and shown to be responsible for the strongest observed spectral structure. Transitions between these excited to excited states are considered, since even if only weakly present, they will not be influenced by opacity effects unlike resonance transitions involving ground configurations. Another two intense continuous emission bands at 3–6 nm and 2–3 nm that dominate the spectra in the shorter wavelength range mainly arise from 4d–5p, 4d5s–4d5s5p, 4f–5g, 4f5s–4f5s5g and 4d–5f, 4d5s–4d5s5f, 4p–5s transitions. Spectral line shape parameters of Gaussian fits to the LTE-gA weighted radiation spectra of each Ho ion were given, enabling direct explanation of recorded spectra. Based on the LTE-gA UTAs formalism parameters, reasonable agreement is obtained between the synthetic spectrum and experimental result enabling some of the observed spectral features to be identified.