Fusui Zhang

Triploid and Tetraploid Zhikong Scallop, Chlamys farreri Jones et Preston, Produced by Inhibiting Polar Body I

Abstract: Triploid scallops are valuable for aquaculture because of their enlarged adductor muscle, and tetraploids are important for the commercial production of triploids. We tested tetraploid induction in the zhikong scallop by inhibiting polar body I in newly fertilized eggs. The ploidy of resultant embryos was determined by chromosome counting at 2- to 4-cell stage and by flow cytometry thereafter. Embryos from the control groups were mostly diploids (79%), along with some aneuploids. Embryos from the treated groups were 13% diploids, 18% triploids, 26% tetraploids, 13% pentaploids, and 36% aneuploids. Tetraploids, pentaploids, and most aneuploids suffered heavy mortality during the first week and became undetectable among the larvae at day 14. Five tetraploids (2%) were found among a sample of 267 spat from one of the replicates, and none was detected at day 450. The adductor muscle of triploid scallops was 44% heavier (P < .01) than that of diploids, confirming the value of the triploid technology in this species.

Upconversion luminescence in Er-doped γ-AlON ceramic phosphors

γ-AlON:Er3+ phosphors with different Er3+ concentration for upconversion luminescence were prepared by a combination of carbothermal reduction and nitridation and solid-state synthesis methods. The effect of Er3+ content on emission spectra was investigated. Under the excitation of 980 nm diode laser, green emission centered at 548 nm and red emission centered at 666 nm were observed, which are ascribed to the transition of S43/2/H211/2→I415/2 and F49/2→I415/2 of Er3+ ions, respectively. The pump power dependence indicates a two-photon process involved in the upconversion luminescence. The ratio of red emission relative to green emission was enhanced with the increase in Er3+ concentration. The possible mechanisms were discussed.

Structural characterization of SiGe/Si dry thermal oxidation

In this paper, a study on the dry thermal oxidation of a graded SiGe layer is proposed. By oxidation of a graded SiGe layer, the effect of Ge pileup was reduced and dependence of the oxidation ambient was analyzed. During oxidation at pure oxide ambient, pure compositions of silicon dioxide are formed without dislocation, and it was clearly proved by the TEM, EDS, SE, and AFM results. Whereas, after oxidation under atmospheric pressure with 21/min mix gas flow of Ar50%+O/sub 2/50%, composition of SiGeO/sub 2/ was found at the top layer. This result can propose an oxidation method optimization of SiGe/Si heterostructures.

Ge condensation characterization of SiGe-on-insulator structure fabricated by separation of oxygen implantation

In this paper we present a virtual strained silicon substrate, full relaxed SiGe-on-insulator (SGOI)(Ge% = 15%) structure with stepwise buffer layers and high quality box layer, fabricated by separation by implantation of oxygen (SIMOX) technique. The Ge condensation effect of the top SiGe layer is found and its dependence on the SIMOX parameters is also reviewed. This result is a unique way to get high Ge content of SGOI/Si heterostructures.

Control of the YSZ biaxial alignment on polycrystalline NiCr substrates by ion beam selective resputtering

(001)-oriented and in-plane aligned yttria-stabilized zirconia (YSZ) films were synthesized on polycrystalline NiCr substrates by ion beam assisted deposition (IBAD). The YSZ biaxial alignment were found to be controlled by the assisted argon ion beam bombardment. The incident angle and energy of the assisted bombarding ion beam strongly influence the alignment. The optimal alignment was obtained with the assisted ion beam bombarding at 55° incident angle and 250–500 energy. The Monte Carlo method was used to simulate the alignment formation with argon ions bombarding the zirconia crystals. Results indicated that when the energy of the bombarding ions is less than 50 eV, there is no obvious difference in the sputtering yields and the radiation damage of zirconia between different incident angles. However with the ion energy increasing, the variation increases rapidly. When the ion energy reaches 250 eV, the sputtering yields and the radiation damage of zirconia induced by Ar+ bombarding along [111] direction (54.7° from the [001]) of the zirconia are much lower than those produced by Ar+ bombarding along other directions. It can be concluded that the (001)-oriented grains are resputtered less than other grains when the assisted ions bombarding at 55° incident angle, which causes YSZ grains with (001) orientation to prevail over initial random oriented grains and form the biaxial alignment.