Outbreak of luminescent disease was reported from Litopenaeus vannamei shrimp farms in Zhangpu County, Southern China during May–July 2011. The clinical signs included fluorescent, less food consumption and high mortality. Bacteria were isolated from the infected shrimps. The pathogen, a luminescent bacterium named VH1 was identified as Vibrio campbellii based on MLSA analysis (16S rDNA, rpoD and toxR). The haemolysin (hly) gene specific in V. campbellii was detected in strain VH1. Pathogenicity test using immersion infection confirmed that strain VH1 was virulent to L. vannamei postlarvae and juveniles, and the LC50 value was 1.55 × 106 CFU mL−1 and 1.7 × 106 CFU mL−1 respectively.

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Multilayer ordered GeSi quantum dots (QDs) with thin Si spacers were obtained via self-assembly on pit-patterned Si(001) substrates. The lateral ordering of GeSi QDs predetermined by the periodic pit pattern results in remarkably improved size uniformity in comparison with random QDs on flat substrates. A much stronger and narrower photoluminescence (PL) peak from ordered QDs were observed than that from random ones, particularly at high excitation power. Such enhanced PL signal was attributed to the high density of states and the uniform distribution of excitons in the ordered and uniform QDs, which can efficiently suppress the Auger effect and the Coulomb screening effect. Moreover, anomalous narrowing of the PL peak from the ordered QDs with the excitation power was observed, which was explained in terms of distributed feedback associated with the periodic stacked GeSi QDs.