In this study, photomodulated reflectance (PR) technique was employed on two different quantum well infrared photodetector (QWIP) structures, which consist of n-doped GaAs quantum wells (QWs) between undoped AlxGa1-xAs barriers with three different x compositions. Therefore, the barrier profile is in the form of a staircase-like barrier. The main difference between the two structures is the dop...

Solid solutions of (1-x)BiFeO₃-xBaTiO₃ (BF-BT, 0.05 ≤ x ≤ 0.98) were prepared and characterized. It was found that the dielectric constant εm, remnant polarization Pr and piezoelectric coefficient d33 reach their maximum values near the rhombohedral-pseudocubic phase boundary. In particular, the 0.7BF-0.3BT composition shows large polarization (Pr > 20 μC/cm²) and a temperature-stable piezoelec...

The PR oxidase, an extracellular enzyme, involved in the conversion of PR toxin into PR acid, was purified from the culture broth of Penicillium roqueforti ATCC 48936. The enzyme has a pI of 4.5 and a molecular mass of approximately 88 kDa, and it is a monomer. The optimum pH for this enzyme is ca. 4.0, and the optimum temperature is 50 degreesC.

We have measured the electrodynamic properties of Y1−xPrxBa2Cu3O7 single crystal thin films as a function of temperature using coherent THz-time-domain spectroscopy. We obtain directly the complex conductivity σ = σ1 + iσ2, the London penetration depth λL, the plasma frequency ωp, and the quasiparticle scattering rate 1/τ . We find that 1/τ drops exponentially rapidly with T below the critical ...

Since the first observation of the photorefractive (PR) effect in polymers, extensive efforts have been directed toward understanding the physics of the PR process in these systems, as well as optimizing polymer composites and glasses for various applications. Despite remarkable progress both in elucidating the mechanisms and processes contributing to the PR effect and in designing organic mate...

A set of ceria, ceria-zirconia (Ce 80 at.%, Zr 20 at.%), ceria-praseodymia (Ce 80 at.%, Pr 20 at.%) and ceria-zirconia-praseodymia (Ce 80 at.%, Zr 10 at.% and Pr 10 at.%) catalysts has been prepared by the solution combustion synthesis (SCS). The effects of Zr and Pr as dopants on ceria have been studied in CO and soot oxidation reactions. All the prepared catalysts have been characterized by c...

In this paper, a gas-kinetic BGK model is constructed for the Rayleigh-Bénard thermal convection in the incompressible flow limit, where the flow field and temperature field are described by two coupled BGK models. Since the collision times and pseudo-temperature in the corresponding BGK models can be different, the Prandtl number can be changed to any value instead of a fixed Pr = 1 in the ori...

The temperature inducible expression system, based on the pL and/or pR phage lambda promoters regulated by the thermolabile cI857 repressor has been widely use to produce recombinant proteins in prokaryotic cells. In this expression system, induction of heterologous protein is achieved by increasing the culture temperature, generally above 37 degrees C. Concomitant to the overexpression of hete...

Organic-inorganic hybrid mesoporous materials such as amino functionalized silica (SBA-Pr-NH2) have received considerable attention due to their basic catalytic applications and adsorption functions. In this work, we investigated the efficient role of SBA-Pr-NH2 as a heterogeneous nano catalyst in the synthesis of 9,10-diaryl-7H-benzo[d,e]imidazo[2,1-a]isoquinolin-7-one derivatives. Application...