Electrochromic Variation of the Infrared Emissivity in Tungsten Oxide Compounds

The so-called plastic technology first developed for the Li-based batteries leads to a new flexible infrared modulator. Orthorhombic monohydrated tungsten oxide (o-WO³ · H₂O) is used as the active insertion element in the LiCoO₂/o-WO³ · H₂O system. To prevent its degradation under air moisture, the device is protected with hermetic plastic and a window. Measurements of the reflectivity values indicate a very good contrast between the bleached and colored states for the first insertion (about 50% contrast in the 2.5–15 μm range), but the contrast between the inserted and de-inserted states is only about 30%. Optical properties follow quite well Drude mechanism.     

Protonic conductivity of β″ and ion-rich β-alumina. II: Ammonium compounds

The conductivity and thermal stability of NH⁺₄, H⁺(H₂O)_nβ″ and ion-rich β-alumina single crystals have been measured by the complex impedance method in the 25–700°C temperature range. Both structures have similar properties, but ion-rich β-alumina shows a higher stability and a lower activation energy (β: 0.18 eV, β″ 0.24 eV below 400°C and 250°C respectively). The room temperature conductivity is about 3×10^-5ω^-1cm^-1. The conducting properties and mechanisms are discussed and compared to other protonic or ionic conductors.     

The neuroblast and angioblast chemotaxic factor SDF-1 (CXCL12) expression is briefly up regulated by reactive astrocytes in brain following neonatal hypoxic-ischemic injury

Background  

Stromal cell-derived factor 1 (SDF-1 or CXCL12) is chemotaxic for CXCR4 expressing bone marrow-derived cells. It functions in brain embryonic development and in response to ischemic injury in helping guide neuroblast migration and vasculogenesis. In experimental adult stroke models SDF-1 is expressed perivascularly in the injured region up to 30 days after the injury, suggesting it could be a therapeutic target for tissue repair strategies. We hypothesized that SDF-1 would be expressed in similar temporal and spatial patterns following hypoxic-ischemic (HI) injury in neonatal brain.     

An alternating direction scheme on a nonuniform mesh for reaction-diffusion parabolic problems

In this paper we develop a numerical method for two-dimensionaltime-dependent reaction-diffusion problems. This method, whichcan immediately be generalized to higher dimensions, is shownto be uniformly convergent with respect to the diffusion problems.This method, which can immediately be generalized to higherdimensions, is shown to be uniformly convergent with respectto the diffusion parameter.     

Internal energy content of n-butylbenzene, bromobenzene, iodobenzene and aniline molecular ions generated by two-photon ionization at 266 nm. A photodissociation study

A technique to investigate photodissociation kinetics on a nanosecond time scale has been devised for molecular ions generated by multiphoton ionization (MPI) using mass-analyzed ion kinetic energy spectrometry. The branching ratio or rate constant has been determined for the photodissociation of the n-butylbenzene, bromobenzene, iodobenzene, and aniline molecular ions generated by MPI at 266 nm. The ion internal energies have been estimated by comparing the measured kinetic data with the previous energy dependence data. The analysis has shown that only those molecular ions generated by two-photon ionization contribute to the photodissociation signals. Around half of the available energy has been found to remain as molecular ion internal energy in the two-photon ionization process. Copyright 1999 John Wiley & Sons, Ltd.