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Effects of 0, 500, 1000, and 1500 ppm (wt/vol) ascorbyl palmitate (AP) on the methylene-blue-and the chlorophyll-sensitized photooxidations of linoleic acid or soybean oil, either in methanol or in a solvent mixture (benzene/methanol, 4:1, vol/vol), were studied during storage under 3300 lux fluorescent light for 5 h. Steady-state kinetic approximation was used to determine a quenching mechanism and quenching rate constant of AP in the chlorophyll-sensitized photooxidation of methyl linoleate in a solvent mixture (benzene/methanol, 4:1, vol/vol). Both methylene blue and chlorophyll greatly increased the photooxidation of linoleic acid and soybean oil, as was expected. AP was extremely effective at minimizing both methylene-blue-and chlorophyll-sensitized photooxidations of linoleic acid and soybean oil, and its effectiveness was concentration-dependent. The addition of 500, 1000, and 1500 ppm AP resulted in 69.3, 83.6, and 94.6% inhibition of methyleneblue-sensitized photooxidation of linoleic acid, respectively, after 5-h storage under fluorescent light. AP showed significantly greater antiphotooxidative activity than α-tocopherol for the reduction of methylene blue-sensitized photooxidation of linoleic acid (P < 0.05). The steady-state kinetic studies indicated that AP quenched singlet oxygen only to minimize the chlorophyll-sensitized photooxidation of oils. The calculated total quenching rate of AP was 1.0 x 10 8 M −1 s −1 . The present results clearly showed, for the first time, the effective singlet oxygen quenching ability of AP for the reduction of photosensitized oxidation of oils.

Dislocation creep behaviors of CoCrFeMnNi were investigated at intermediate temperatures. Shape of creep curves, stress exponents and the activation energies at high stresses (> 40 MPa) were distinctly different from those at low stresses, suggesting the transition of creep mechanism from climb-controlled creep to viscous glide creep. Lattice strain energy of dislocations plays an important role on the distribution of atoms over the configurational entropy in the vicinity of dislocation. The excellent agreement between the experimental transition stress and the theoretical stress using the data of Cr suggests that Cr is the most influential element to the viscous glide at high stresses. IMPACT STATEMENT We report climb-to glide-creep transition in CoCrFeMnNi first time. The transition to viscous glide is attributed to dragging of dislocations caused by change of dislocation-line-energy and mobility of segregated atoms.