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Enhanced particle transport events are discovered and analyzed as the density limit of the J-TEXT tokamak is approached. Edge shear layer collapse is observed and the ratio of Reynolds power to turbulence production decreases. Simultaneously, the divergence of turbulence internal energy flux (i.e. turbulence spreading) increases, indicating that shear layer collapse triggers an outward spreading event. Studies of correlations show that the enhanced particle transport events are quasi-coherent, and manifested primarily in density fluctuations which exhibit positive skewness. Electron adiabaticity emerges as the critical parameter which signals transport event onset. For α < 0.35 as density approaches the Greenwald density, both turbulence spreading and density fluctuations rise rapidly. Taken together, these results elucidate the connections between edge shear layer, density fluctuations, particle transport events, turbulence spreading and plasma edge cooling as the density limit is approached.

An 8-week study was conducted to determine folic acid requirement and its effect on antioxidant capacity and immunity in juvenile Chinese mitten crab Eriocheir sinensis (Milne-Edwards, 1853), followed by a challenge assay with the pathogen Aeromonas hydrophila for 2 weeks. Folic acid was added to a basal diet at seven levels (0, 0.5, 1.0, 2.0, 4.0, 8.0, 16.0 mg folic acid kg−1 diet), and a diet free of folic acid and vitamin B12 was also included as a control. Crabs were fed twice daily in 32 tanks with 7.76–8.17 mg oxygen L−1, 25.0–31.0 °C and 7.5–8.3 pH. Growth and feed efficiency were significantly greater in crabs fed ≥2.0 mg folic acid kg−1, but not significantly different between crabs fed diets >2.0 mg folic acid. The superoxide dismutase activity and glutathione S-transferase activity were highest in crabs fed ≥2.0 mg folic acid kg−1, followed by those fed 0.5 and 1.0 mg folic acid kg−1, and the control diet. The malondialdehyde content was highest in crabs fed the control diet, followed by those fed 0 mg folic acid kg−1, and the lowest value occurred in those fed ≥0.5 mg folic acid kg−1. Phenoloxidase activity and total haemocytes were significantly higher in crabs fed ≥2.0 mg folic acid kg−1 than other diets. Crabs fed 2.0 mg folic acid kg−1 had the highest lysozyme, acid phosphatase and alkaline phosphatase activities but the lowest cumulative mortality. The optimum dietary folic acid requirement by E. sinensis was estimated at 2.29–2.90 mg kg−1 diet.

The Young’s modulus of micromechanical silicon films is very different from bulk silicon structures. It is very meaningful to test Young’s modulus of micromechanical silicon films in related studies. Owing to its small and fragile characterstics, a suitable non-contact and nondestructive method is needed to test the Young’s modulus of micromechanical silicon films with plate-like and beamlike structures. Utilizing acoustic excitation and optical detection method based on theoretical analysis, a new resonant method is presented to determinate Young’s modulus of micromachined silicon films. By using this novel method, more accurate results have been achieved and the measuring error is 11%, better than the reported 14%.

Recently, high luminance and high efficiency were realized in organic thin-film electroluminescence devices with multilayer structure, which include an emitting layer, a hole transporting layer, and an electron transporting layer. Generally these carrier transporting layers have the properties of inhibiting different type carriers such as transporting hole while inhibition electrons, by which the carrier are confinement in emitting layer. In this letter, we report some properties of hole blocking layers which were realized in a double layer structure with ITO/emitting layer/hole blocking layer/Al. In this structure, the emitting layer was 1,1,4,4,-tetraphenyl-1,3-butadiene(TPB) doped poly(N-vinylcarbazole) (PVK), which has large hole mobility, and hole blocking layer was PBD.