Behaviour of silicon ointment for power-cable insulation under external heating

Journal of Thermal Analysis and Calorimetry - The burning process and typical fire parameters of power-cable silicon ointment were explored experimentally using a cone calorimeter, and the effects...     

分光光度法测定三氧化铀中的硫酸根

采用TBP-萃淋树脂吸附三氧化铀样品中的铀,硫酸根与铬酸钡进行交换反应后,直接比色法测定硫酸根的含量。实验中研究了三氧化铀样品中硫酸根含量测定的样品制备、分离、反应酸度,煮沸时间,铬酸钡用量等影响因素。优化条件下,采用硝酸(5mol/L)淋洗、1mL HCl溶液(2.5mol/L)调节溶液中酸浓度、使用2mL BaCrO_4进行交换反应、煮沸3min,得到方法相对标准偏差小于10%,加标回收率为92.9%～110%。实验结果表明,直接显色的测定方法灵敏、快速、准确度高。方法测定条件易于获得,适于推广应用。     

Investigation on effects of thickness on ignition characteristics and combustion process of the oil-impregnated transformer insulating paperboard

Effects of thickness on ignition characteristics and combustion process of the oil-impregnated transformer insulating paperboard were investigated experimentally by cone calorimeter. Five thicknesses of transformer insulating paperboard, including 0.5, 1.0, 1.5, 2.0 and 3.0 mm were taken into account together with five radiation intensities between 25 and 80 kW m^?2. According to the experimental results on ignition characteristics, the 0.5-mm paperboard for all radiation intensities and the 1.0-mm paperboard with the radiation heat flux less than 35 kW m^?2 were thermal thin material. The 1.0-mm paperboard under higher radiation intensities and the paperboard with the thicknesses of 1.5, 2.0 and 3.0 mm were thermal thick material. The heat release rate (HRR) of oil-impregnated transformer insulating paperboard decreased with its thickness. Due to the different pyrolysis processes, the number of HRR peaks increased with the thickness of paperboard. The CO and CO₂ production rate and the O₂ consumption rate were all decreased with the paperboard thickness basically. There was an increase in the CO production rate at the end of fire duration, since the incomplete combustion process occurred at this stage. The increase in the CO production rate was more obvious in the experiments under lower external radiation heat fluxes.     

Layers of noncooperative games

We model and analyze classes of antagonistic stochastic games of two players. The actions of the players are formalized by marked point processes recording the cumulative damage to the players at any moment of time. The processes evolve until one of the processes crosses its fixed preassigned threshold of tolerance. Once the threshold is reached or exceeded at some point of the time (exit time), the associated player is ruined. Both stochastic processes are being “observed” by a third party point stochastic process, over which the information regarding the status of both players is obtained. We succeed in these goals by arriving at closed form joint functionals of the named elements and processes. Furthermore, we also look into the game more closely by introducing an intermediate threshold (see a layer), which a losing player is to cross prior to his ruin, in order to analyze the game more scrupulously and see what makes the player lose the game.