Aim: To increase the transformation rate of L L-sorbose to 2-keto-L L-gulonic (2-KLG) acid in a two-step process of L L-ascrobic acid manufacture by ion beam. Methods and Results: Gluconobacter oxydans (GO29) and Bacillus megaterium (BM80) were used in the present study. Ion implantation was carried out with the heavy ion implantation facility at the institute of Plasma Physics in China. 2-KLG in whole culture broth was determined by iodometry. Mutants were screened by singlecolony isolation and 2-KLG accumulation in broth. GO29 and BM80 were implanted by either hydrogen ions (H + ) or nitrogen ions (N + ) with various doses, respectively. The average transformation rate of GM112-302 bred by ion beam in Gram-molecule was increased from 79AE3 to 94AE5% after eight passages in shaking flasks. Furthermore, in 180-ton fermentors in Jiangsu Jiangshan Pharmaceutical Co. Ltd, the transformation rate was stable at 92AE0%, indicating a producer could get 0AE99 kg of gulonic acid from 1AE0 kg of sorbose. Conclusion: Ion beam as a new mutation source had potential advantages in breeding. Comparing with original mixture GO29 and BM80, GM112-302 is more efficient in accumulating 2-KLG, especially at the later phase. Significance and Impact of the Study: GM112-302 bred by ion beam implantation dramatically increased the transformation rate by 19AE2%, which greatly increased efficiency and reduced the cost of L L-ascorbic acid manufacture in a two-step process.

EAST has been equipped with two high power lower hybrid current drive (LHCD) systems with operating frequencies of 2.45 GHz and 4.6 GHz. Comparative LHCD experiments with the two different frequencies were performed in the same conditions of plasma for the first time. It was found that current drive (CD) efficiency and plasma heating effect are much better for 4.6 GHz LH waves than for the one with 2.45 GHz. High confinement mode (H-mode) discharges with 4.6 GHz LHCD as the sole auxiliary heating source have been obtained in EAST and the confinement is higher with respect to that produced previously by 2.45 GHz. A combination of ray-tracing and Fokker-Planck calculations by using the C3PO/LUKE codes was performed in order to explain the different experimental observations between the two waves. In addition, the frequency spectral broadening of the two LH wave operating frequencies was surveyed by using a radio frequency probe.

The very weak S(0)-S(3) electric quadrupole transitions of the second overtone band of molecular hydrogen have been recorded in the laboratory by continuous-wave cavity ring-down spectroscopy near 0.8 μm. The ultrahigh sensitivity of the spectrometer (α min ∼ 1 × 10 −10 cm −1 ) allows us to detect the considered transitions at a relatively low sample pressure (50-750 torr). The line positions, intensity, and pressure-shift coefficients are derived from a fit of the line shape using a Galatry profile. Compared with literature values, the relative differences between the experimental and theoretical transition intensities are reduced by one order of magnitude, reaching a value of about 2% mainly dependent of the line-shape function adopted for the profile fitting. The thermal equilibrium relative intensity of the S(1) to S(0) line is determined with an accuracy of 0.4%, which can be used to probe the ortho-to para-H 2 concentration ratio. Our measurements confirm the quality of the high-level ab initio calculations, including the relativistic and quantum electrodynamics corrections.