Superconductivity due to charge transfer to the CuO2 sheet from the (Tl,Pb) O layer in Tl0.5Pb0.5Sr2−xNdxCuO5−δ

The superconductivity of Tl_0.5Pb_0.5Sr_2−xNd_xCuO_5−δ was observed for x ≥ 0.3, although the calculated Cu valence assuming Tl³⁺ and Pb⁴⁺ is slightly above or below 2.0. The binding energy of the Tl and Pb 4f core levels measured by XPS shifted to higher energy than those of Tl³⁺ and Pb⁴⁺ in the reference materials, showing that the Tl and Pb valences are lower than 3 + and 4 +, respectively. These observations strongly suggest that holes in the CuO₂ sheet are created by charge transfer from the (Tl,Pb)O layer, similar to the double-layered Tl---Ba cuprates.

In contrast, the temperature variation of electrical conductivity of Tl_0.5Pb_0.5Sr₂CuO_5−δ changed from metallic to semiconducting with increasing oxygen deficiency, δ, and no superconductivity was observed through any control of δ. Although XPS measurement also suggested that Tl and Pb valences lowered with increasing oxygen deficiency, δ, the reason why the system did not show superconductivity can be understood by the depletion of oxygen from the CuO₂ plane during deoxygenation.     

Detection of small RNA molecules by a combination of branched rolling circle amplification and bioluminescent pyrophosphate assay

Polyfluorinated compounds (PFCs) are a relatively new and diverse set of compounds analyzed as contaminants in food. Their unique physical-chemical properties dictate the methods used for their analysis. Current analyses of the more volatile PFCs involve gas chromatography–mass spectrometry; liquid chromatography–tandem mass spectrometry is generally used for the less volatile PFCs. Considerations in the analysis of PFCs in foods include contamination from the widespread presence of materials that contain various PFCs, endogenous interfering compounds, and matrix effects. Future opportunities for research on PFCs in food exist, particularly in the areas of biological molecule–PFC interactions and the effects of food processing on these interactions. Future research will be facilitated by the synthesis of a wider variety of analytical standards.     

Multivariable RBF-ARX model-based robust MPC approach and application to thermal power plant

For a class of smooth nonlinear multivariable systems whose working-points vary with time and the future working-points knowledge are unknown, a combination of a local linearization and a polytopic uncertain linear parameter-varying (LPV) state-space model is built to approximate the present and the future system’s nonlinear behavior, respectively. The combination models are constructed on the basis of a matrix polynomial multi-input multi-output (MIMO) RBF-ARX model identified offline for representing the underlying nonlinear system. A min–max robust MPC strategy is designed to achieve the systems’ output-tracking control based on the approximate models proposed. The closed loop stability of the MPC algorithm is guaranteed by the use of time-varying parameter-dependent Lyapunov function and the feasibility of the linear matrix inequalities (LMIs). The effectiveness of the modeling and control methods proposed in this paper is illustrated by a case study of a thermal power plant simulator.     

Highly efficient and broadband Si homojunction structured near-infrared light emitting diodes based on the phonon-assisted optical near-field process

We fabricated a highly efficient, broadband light emitting diode driven by an optical near field generated at the inhomogeneous domain boundary of a dopant in a homojunction bulk Si crystal and evaluated its performance. To fabricate this device, a forward current was made to flow through a Si p–n junction to anneal it. During this process, the device was irradiated with near-infrared light, producing stimulated-emission light using a two-step phonon-assisted process triggered by the optical near field, and the annealing rate was controlled in a self-organized manner. The device emitted light in a wide photon energy region of 0.73–1.24 eV (wavelength 1.00–1.70 μm). The total power of the emitted light with 11 W of electrical input power was as high as 1.1 W. The external power conversion efficiency of the emitted light was 1.3%, the differential external power conversion efficiency was 5.0%, the external quantum efficiency was 15%, and the differential external quantum efficiency was 40%. The dependency of the emitted light power density on the injected current density clearly showed a characteristic reflecting the two-step phonon-assisted transition process.     

Four-Body Structure of Λ Hypernuclei and 4He Tetramer System

Gaussian Expansion Method has been applied to four-body calculations of ${^4_{\Lambda}{\rm H}}$ and ${^4_{\Lambda}{\rm He}}$ , and four-body calculation of ⁴He tetramer. We found that Λ N? Σ N coupling is important to make bound A = 4 hypernuclei. The binding energies of the tetramer ground state and excited states are obtained as 558.98 and 127.33 mK.     

Evaluating the coupling strength of electron–hole pairs and phonons in a 0.9 μm-wavelength silicon light emitting diode using dressed-photon–phonons

We investigated the coupling strength between electron–hole pairs and phonons in a silicon light emitting diode (Si-LED) fabricated by dressed-photon-assisted annealing. This Si-LED emitted light in the 1.4 eV photon energy (0.9 μm wavelength) band, and phonon sidebands were observed in the emission spectrum. From a comparison with simulation results, these sidebands were found to be due to coupling of electron–hole pairs with LO-mode and TO-mode coherent phonons via dressed-photon–phonons. The value of the Huang–Rhys factor, $S$ , representing the coupling strength between the electron–hole pairs and the phonons was estimated to be $4.08 \pm 0.02$ .     

Flexibility Control of Two-Dimensional Coordination Polymers by Crystal Morphology: Water Adsorption and Thermal Expansion

Layer flexibility in two-dimensional coordination polymers (2D-CPs) contributes to several functional materials as it results in anisotropic structural response to external stimuli. Chemical modification is a common technique for modifying layer structures. This study demonstrates that crystal morphology of a cyanide-bridged 2D-CP of type [Mn(salen)]₂[ReN(CN)₄] ( 1 ) consisting of flexible undulating layers significantly impacts the layer configuration and assembly. Nanoplates of 1 showed an in-plane contraction of layers with a longer interlayer distance compared to the micrometer-sized rod-type particles. These effects by crystal morphology on the structure of the 2D-CP impacted the structural flexibility, resulting in dual-functional changes: the enhancement of the sensitivity of structural transformation to water adsorption and modification of anisotropic thermal expansion of 1 . Moreover, the nanoplates incorporated new adsorption sites within the layers, resulting in the uptake of an additional water molecule compared to the micrometer-sized rods.     

Determination of ASP3258, a novel phosphodiesterase type 4 inhibitor,in rat plasma by high‐performance liquid chromatography with fluorescence detection and its application to pharmacokinetic study

The potent phosphodiesterase 4 inhibitor ASP3258 contains a carboxylic acid moiety and a naphthyridine ring and is a novel therapeutic agent for asthma and chronic obstructive pulmonary disease. To support the drug development of ASP3258, we developed and validated a simple method for its determination in rat plasma. Following the addition of the analog AS1406604‐00 as an internal standard, plasma samples were processed using C₁₈‐bonded solid‐phase extraction cartridges under acidic conditions and injected into a high‐performance liquid chromatography system with fluorescence detection. Chromatographic separation was achieved on a Shiseido Capcell Pak C₁₈ UG120 column (3.0 × 150 mm, 5 µm) with a mobile phase consisting of acetonitrile–0.5% acetic acid (50:50, v/v). HPLC eluent was monitored with a fluorescence detector set at a wavelength of 315 nm for excitation and 365 nm for emission. The calibration curve was linear over a range of 2.5–250 ng/mL. Validation data demonstrated that the method is selective, sensitive and accurate. In addition, the present method was successfully applied to rat plasma samples from a pharmacokinetic study. Copyright © 2014 John Wiley & Sons, Ltd.     

Two-dimensional array of room-temperature nanophotonic logic gates using InAs quantum dots in mesa structures

We present a detailed study of the dynamics of light in passive nonlinear resonators with shallow and deep intracavity periodic modulation of the refractive index in both longitudinal and transverse directions of the resonator. We investigate solutions localized in the transverse direction (so-called Bloch cavity solitons) by means of envelope equations for underlying linear Bloch modes and solving Maxwell’s equations directly. Using a round-trip model for forward and backward propagating waves we review different types of Bloch cavity solitons supported by both focusing (at normal diffraction) and defocussing (at anomalous diffraction) nonlinearities in a cavity with a weak-contrast modulation of the refractive index. Moreover, we identify Bloch cavity solitons in a Kerr-nonlinear all-photonic crystal resonator solving Maxwell’s equations directly. In order to analyze the properties of Bloch cavity solitons and to obtain analytical access we develop a modified mean-field model and prove its validity. In particular, we demonstrate a substantial narrowing of Bloch cavity solitons near the zero-diffraction regime. Adjusting the quality factor and resonance frequencies of the resonator optimal Bloch cavity solitons in terms of width and pump energy are identified.