Papers by Keyword: High Hydrostatic Pressure

Abstract: This paper investigated the effect of high hydrostatic pressure processing on sensory quality, physical and chemical quality and nutrients of strawberry juice.The L*,E,soluble solid,titratable acid and total phenols were not significantly affected by HHP treatment (p<0.05), the a* and b* value were significantly increased with the extension of pressure and time except 400 MPa. The suspension stability showed a gradual rise trend. High pressure can well maintain the anthocyanins of strawberry juice.Well,under 500 MPa,10~40min ,the content of anthocyanins were significantly changed (p<0.05),but the retention rate of anthocyanins is 90%~95%.

Abstract: Solid phase epitaxial regrowth (SPER) of amorphized layer in Czochralski grown silicon (Cz-Si) created by self-implantation (Si+ dose 2x1016 cm-2, energy 150 keV), subsequently annealed for 5 h at up to 1400 K under Ar pressure up to 1.4 GPa, was investigated by Secondary Ion Mass Spectrometry (SIMS) and X-ray methods. Annealing of Cz-Si:Si resulted in pressure-dependent SPER with a marked carbon and oxygen gettering within regrown region. Depth profiling of carbon and oxygen contaminants provides useful information concerning SPER in implanted single crystalline silicon.

Abstract: Stress relaxation processes accompanying intermetallic growth during reactive diffusion between Cd and Ni have been studied by the methods of optical and scanning electron microscopy, provided with X-ray microanalysis. The experiments were carried out with the two-layer Cd-Ni samples at 250 and 280oC under hydrostatic pressures 350-900 MPa. The observed processes have been compared with those occurred at low pressures to demonstrate that the mechanisms of stress relaxation and thus the kinetics of intermetallic growth essentially depend on applied hydrostatic pressure. New mechanisms of stress relaxation were found, such as Cd extrusion and Cd whisker growth, which accompanied formation of Cd21Ni5 compound. It is shown, that the whisker growth is more probable at lower temperatures when the grain size is smaller, and the stress gradient, which support a driving force for whisker formation, is higher. An atomic mechanism for whisker growth, based on diffusion climbing of dislocation loops produced by Bardeen-Herring source for building new atomic layers, has been discussed.

Abstract: The effect of treatment at up to 1400 K (HT) under enhanced hydrostatic pressure (HP, up to 1.2 GPa) on helium implanted single crystalline silicon (Si:He, He ion dose up to 6x1017cm-2, energy up to 300 keV) has been investigated by transmission electron microscopy, secondary ion mass spectrometry, photoluminescence and X-Ray methods. The treatment of Si:He at ≤ 920 K - HP results in a formation of buried nano-structured layers containing helium filled cavities/bubbles and numerous extended defects; many less dislocations are created at ≥ 1270 K in Si:He treated under HP. HP affects the recrystallization of amorphous Si, diffusivity of implanted He and of implantation-induced defects and thus promotes the creation of more but smaller He-filled cavities/bubbles as well as other defects near the range of implanted He+.

Abstract: The evolution of nitrogen related infrared vibrational spectra of CZ-Si implanted with nitrogen, with doses 1017 ion/cm2 and 1018 ion/cm2, at 140 keV, was studied after annealing at 1130°C/5h under different hydrostatic pressures, from 1 bar to 10.7 kbar. It was found for each pressure applied, that the increased nitrogen dose leads to transformation of broadband spectra to the fine structure ones, corresponding to crystalline silicon nitride. The spectral position of observed sharp peaks in the investigated pressure region is red shifted in comparison to the peaks of crystalline silicon oxynitride found recently by other investigators in nitrogen-containing poly-Si as well as in a residual melt of nitrogen-doped CZ-Si. The application of pressure during annealing results in further red shift of the nitrogen-related bands. The observed decrease of frequency of vibrational bands is explained in terms of the pressure induced lowered incorporation of oxygen into growing oxynitride phase.