For the finishing of difficult-to-machine materials, plasma-assisted polishing (PAP), which combines modification by water vapor plasma and polishing by a soft abrasive, was proposed. Optimization of ...plasma oxidation and abrasive polishing was conducted to increase the material removal rate of PAP, which was applied to 4H-SiC (0001). It was found that with a low concentration of water vapor in helium gas, the plasma oxidation rate was greatly increased. Also, because of the different oxidation rates of the four types of terrace that appear alternately in 4H-SiC, a high removal rate of the oxide was necessary to obtain a uniform step–terrace structure with atomic order.
A major quantitative trait locus (QTL) controlling response to photoperiod, Hd1, was identified by means of a mapbased cloning strategy. High-resolution mapping using 1505 segregants enabled us to ...define a genomic region of ∼12 kb as a candidate for Hd1. Further analysis revealed that the Hd1 QTL corresponds to a gene that is a homolog of CONSTANS in Arabidopsis. Sequencing analysis revealed a 43-bp deletion in the first exon of the photoperiod sensitivity 1 (se1) mutant HS66 and a 433-bp insertion in the intron in mutant HS110. Se1 is allelic to the Hd1 QTL, as determined by analysis of two se1 mutants, HS66 and HS110. Genetic complementation analysis proved the function of the candidate gene. The amount of Hd1 mRNA was not greatly affected by a change in length of the photoperiod. We suggest that Hd1 functions in the promotion of heading under short-day conditions and in inhibition under long-day conditions.
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