Lp-Lq Estimate of the Stokes Operator and Navier–Stokes Flows in the Exterior of a Rotating Obstacle

We consider the motion of a viscous fluid filling the whole three-dimensional space exterior to a rotating obstacle with constant angular velocity. We develop the L _p -L _q estimates and the similar estimates in the Lorentz spaces of the Stokes semigroup with rotation effect. We next apply them to the Navier–Stokes equation to prove the global existence of a unique solution which goes to a stationary flow as t → ∞ with some definite rates when both the stationary flow and the initial disturbance are sufficiently small in L _3,∞ (weak-L ₃ space).     

Deep levels and growth conditions of LPE GaAs crystals

Deep levels in LPE GaAs were studied in relation to growth conditions. The residual deep levels in LPE layers are hole traps 0.50 and 0.65 eV above the top of the valence band. Their concentrations are of the order of 10¹³ cm^-3 for growth temperatures between 650 and 840°C, and increase with increasing growth temperature. The activation energy of incorporation is about 0.7 eV, which is very close to that of an arsenic vacancy. It is also noted that their concentrations near the grown surface are independent of the growth temperature. This indicates that the hole traps undergo an annealing effect after the growth period. From the experimental results for Fe and oxygen doping, each impurity acts as a deep level only when it makes a complex defect with a gallium vacancy, otherwise they are shallow levels, The distribution coefficients at 750°C are 1 × 10^-7 and 1.1 × 10^-5 for the deep and Fe and the shallow acceptor, respectively.     

Dechlorination of poly(vinyl chloride) using NaOH in ethylene glycol under atmospheric pressure

A solution of NaOH dissolved in ethylene glycol (EG) was effective in the dechlorination of poly(vinyl chloride) (PVC) at atmospheric pressure. The degree of dechlorination increased with increasing temperature, reaching a maximum of 97.8% at 190 °C. The dechlorination proceeded under chemical control and exhibited first-order kinetics with an apparent activation energy of 170 kJ mol⁻¹. The apparent rate constant for dechlorination in 1.0 M NaOH/EG was approximately 150 times greater than that in 1.0 M NaOH/H₂O. In addition, dechlorination was faster at atmospheric pressure in NaOH/EG than under high pressure in NaOH/H₂O. The dechlorination reaction occurs via a combination of E2 and S_N2 mechanisms.     

Average electron tunneling route of the electron transfer in protein media

We present a new theoretical method to determine and visualize the average tunneling route of the electron transfer (ET) in protein media. In this, we properly took into account the fluctuation of the tunneling currents and the quantum-interference effect. The route was correlated with the electronic factor in the case of ET by the elastic tunneling mechanism. We expanded by the interatomic tunneling currents 's. Incorporating the quantum-interference effect into the mean-square interatomic tunneling currents, denoted as , we could express as a sum of variant Planck's over 2pi(2). Drawing the distribution of on the protein structure, we obtain the map which visually represents which parts of bonds and spaces most significantly contribute to . We applied this method to the ET from the bacteriopheophytin anion to the primary quinone in the bacterial photosynthetic reaction center of Rhodobacter sphaeroides. We obtained 's by a combined method of molecular dynamics simulations and quantum chemical calculations. In calculating , we found that much destructive interference works among the interatomic tunneling currents even after taking the average. We drew the map by a pipe model where atoms a and b are connected by a pipe with width proportional to the magnitude of . We found that two groups of 's, which are mutually coupled with high correlation in each group, have broad pipes and form the average tunneling routes, called Trp route and Met route. Each of the two average tunneling routes is composed of a few major pathways in the Pathways model which are fused at considerable part to each other. We also analyzed the average tunneling route for the ET by the inelastic tunneling mechanism.     

A novel practical synthesis of benzothiazoles via Pd-catalyzed thiol cross-coupling

A convenient synthesis of substituted benzothiazoles from 2-bromoanilides has been accomplished. The various 2-bromoanilides were reacted with an alkyl thiolate in high yields using a palladium catalyst. The resulting sulfides were easily converted to the corresponding benzothiazoles via the simultaneous generation of thiols and condensation under basic or acidic conditions.     

Adsorption kinetics of carcinogens to DNA liquid crystalline gel beads

Adsorption behaviors of acridine orange (AO) and biphenyl (BP) to DNA liquid crystalline gel (LCG) beads in aqueous dispersing solution have been studied theoretically and experimentally. A theoretical consideration based on nonequilibrium thermodynamics predicted that the time course of the adsorption process is expressed with a scaled equation, and a scaled number of adsorbed carcinogen molecules ? is expressed with the square root of a scaled immersion time t, ? proportional, variant square root t at early stage, whereas it is expressed with a power law function 1 - ? proportional, variant (te - t)3/2 for ?0 > 1 and an exponential equation ?0 - ? proportional, variant e-t/alpha tau0 for ?0 > 1 at later stages of adsorption. Here, ?0 is the ratio of the initial number of carcinogen molecules in the dispersing solution to the number of the sites of adsorption of carcinogen molecules in the beads, te is the scaled equilibrium time of adsorption, tau0 is a time constant for adsorption, and alpha is a constant. Observed adsorption processes for AO were well expressed by the predicted ones, and the fitting parameters ?0 and tau0 increased with increasing cobalt chloride concentration CCo used for preparation of the beads, and both saturated above CCo > or = 400 mM for the adsorption of AO, whereas the adsorption processes for BP were expressed with the square root function. These results indicate that (1) the adsorption process at early stage is explained by diffusion-limited binding of the carcinogen molecules to DNA beads, and the time range of the early stage depends on the solubility (the solubility of AO in water is high whereas that of BP is low); and (2) the process at later stages depends on the balance of the numbers of adsorption sites and carcinogen molecules.     

Melting and swelling behaviors of UV-irradiated gelatin gel microcapsules

Gelatin gel microcapsules with a narrow size distribution have been prepared for the use of regenerative therapy by means of SPG (Shirasu porous glass) emulsification and UV-induced cross linking, and the melting and swelling behaviors of the gel membrane of the microcapsules were observed. The gel melting temperature was proportional to the 2/3 power of UV irradiation time t for tor=1 h. The average cross-sectional area of the microcapsules that remains insoluble normalized by that at 25 degrees C monotonically increased with temperature for tor=1 h. Repeated quenching of the gel microcapsules between two temperatures (25 and 40 degrees C) induced a reversible size change, which was attributed to the helix-coil transition of collagen molecules locally. From a theoretical consideration of gel particles, the observed gel melting behavior was explained well, and the scaled volume of the microcapsules was expressed as a function of scaled temperature with four fitting parameters for t相似文献