A Study of Estimating the Safe Storage Life, Self-accelerating Decomposition Temperature and Critical Temperature of Thermal Explosion of Double-base Propellant Using Isothermal and Non-isothermal Decomposition Behaviours

A method of estimating the safe storage life （τ）, self-accelerating decomposition temperature （TsADT） and critical temperature of thermal explosion （Tb） of double-base propellant using isothermal and non-isothermal decomposition behaviours is presented. For double-base propellant composed of 56±1wt% of nitrocellulose （NC）, 27±0.5wt% of nitroglycerine （NG）, 8.15±0.15wt% of dinitrotoluene （DNT）, 2.5±0.1wt% of methyl centralite, 5.0±0.15wt% of catalyst and 1.0±0.1wt% of other, the values of r of 49.4 years at 40℃, of TSAOT of 151.35℃ and of Tb of 163.01℃ were obtained.

Microstructure Evolution of T91 Heat-Resistant Steels after Long-Time Aging

To investigate the evolution of microstructure damage degree and the precipitated phases of heat-resistant metal in power plant under high temperature and stress environment, the high- temperature aging tests were conducted to investigate the aging behavior of T91 steel at different temperatures and stress. The optical microscopy, scanning electron microscopy, and transmis- sion electron microscopy were used to investigate the structure and precipitated phases, the results showed that the orientation characteristics of tempered martensite was dispersed, and the grain size is obviously increased. The density of dislocation decreased with increasing temperature and stress. The important strengthen- ing phase of M23C6 （M=Fe, Cr） was coarsened by the diffusion of main alloying elements Cr, while the smaller size MX （M=Nb,V; X=C, N） phase distributed in the grain is relatively stable in the aging.

Online aging study of a high rate MRPC

With the constant increase of accelerator luminosity, the rate requirements of MRPC detectors have become very important, and the aging characteristics of the detector have to be studied meticulously. An online aging test system has been set up in our lab, and in this paper the setupof the system is described and the performance stability of a high-rate MRPC studied over a long running time under a high luminosity environment. The high rate MRPC was irradiated by X-rays for 36 days and the accumulated charge density reached 0.1 C/cm2. No obvious performance degradation was observed for the detector.

Ageing of GaN HEMT devices： which degradation indicators？

A following of diverse degradation indicators during the ageing in operational conditions of A1- GaN/GaN HEMTs （high electron mobility transistors） is proposed. Measurements of pulsed I-V, Schottky barrier height, RF output power and gate current versus output power during the early phase of the ageing test （2000 h on a 6000 h total） are presented. These preliminary results give insight on some of the principal degradation indicators that are interesting to follow during an ageing test close to operational conditions on such components.

Effect of temperature and moisture on the luminescence properties of silicone filled with YAG phosphor

In order to determine the environmental effects on the luminescence properties of a phosphor layer for high-power light emitting diodes, a high humidity and temperature test （85℃/85%RH） and a thermal aging test （85℃） were performed on silicone/YAG phosphor composites. The luminescence properties of silicone/phosphor composites are monitored by a fluorescence spectrometer. The results show that high temperature could result in an increase in conversion efficiency of composites during the early aging stage and red shift of YAG phosphor; and high humidity could result in a significant decrease in conversion efficiency of composites while having a small influence upon the optimal excitation wavelength of the YAG phosphor.