Development of the gas puffing imaging diagnostic on J-TEXT tokamak.

Edge turbulence is important for plasma confinement, so the gas puffing imaging (GPI) diagnostic was proposed on the J-TEXT tokamak for the two-dimensional measurement of turbulence in the edge region. GPI is a diagnostic of plasma turbulence that uses a puff of neutral gas at the plasma edge to increase the local visible light emission for improved space-time resolution of plasma fluctuations. Considering the conditions of J-TEXT, the observation area is 21° away from the position of the optical system in the toroidal direction, and the observation area is 10 cm × 10 cm inside and outside the last closed flux surface. To have a lower divergence of the gas flow, the gas puff nozzle is specially designed. An interface has been developed for operation. To photograph the line radiation generated by the neutral gas cloud along the magnetic field lines, the optical system is designed. It is composed of a quartz glass, mirrors, commercial lenses, filters, and high-speed cameras. The high-speed camera can capture the line radiation with a speed up to 180 000 frames/s with 256 pixels × 256 pixels and an exposure time of 5 µs. In a recent experiment, the new GPI diagnostic has obtained some preliminary pictures.

A young male adolescent with feminine appearance: diagnosis of 46, XX syndrome neglected for 4 years with gynaecomastia presentation.

Gynaecomastia is common in infancy and adolescent boys, but other inciting causes should be kept in mind and necessitate further evaluation should be conducted to determine any underlying conditions. A 22-year-old unmarried male adolescent visited our endocrinology clinic for feminine appearance despite operations for bilateral gynaecomastia 4 years ago. Physical examination showed inverted triangular distribution of pubic hair, sparse beard, small-sized testes, flaccid short penis and surgical scar of the chest wall. Serum hormones study revealed primary hypergonadotropic hypogonadism, and cytogenetic study disclosed female complement (46, XX). The authors recommend that sexual chromosome abnormality should be considered in patients with hypogonadism to avert androgen deficiency-related complications early and that long-term team care should be provided to improve the patient's health-related quality of life.

Optical properties and carrier dynamics of self-assembled GaN/Al(0.11)Ga(0.89)N quantum dots.

GaN quantum dots were grown on an Al(0.11)Ga(0.89)N buffer layer by using flow rate modulation epitaxy. The Stranski-Krastanov growth mode was identified by an atomic force microscopy study. The thickness of the wetting layer is about 7.2 monolayers. The temperature dependent photoluminescence studies showed that at low temperature the localization energy, which accounts for de-trapping of excitons, decreases with the reducing dot size. The decrease in emission efficiency at high temperature is attributed to the activation of carriers from the GaN dot to the nitrogen vacancy (V(N)) state of the Al(0.11)Ga(0.89)N barrier layer. The activation energy decreases with reducing dot size.