Ga As太阳电池是目前大部分航天器的主要动力来源,因此有必要对其在空间辐射环境条件下的性能衰减进行评估,以优化电池的辐射防护措施,保证电池在空间应用的高可靠和长寿命的要求。本文在Ga As太阳电池辐射损伤原理的基础上,分别研究了...Ga As太阳电池是目前大部分航天器的主要动力来源,因此有必要对其在空间辐射环境条件下的性能衰减进行评估,以优化电池的辐射防护措施,保证电池在空间应用的高可靠和长寿命的要求。本文在Ga As太阳电池辐射损伤原理的基础上,分别研究了等效注量衰减、非电离能损衰减和缺陷损伤三种评估方法的物理机制、建模思路和模型,并对三种方法进行了对比分析。展开更多
Paraffin microcapsules with urea-formaldehyde polymer skin are prepared by in-situ polymerization of urea-formaldehyde prepolymer. It is found that the pH value of the aqueous solution, addition of NaCl and temperatur...Paraffin microcapsules with urea-formaldehyde polymer skin are prepared by in-situ polymerization of urea-formaldehyde prepolymer. It is found that the pH value of the aqueous solution, addition of NaCl and temperature affect the developing rate of microcapsules, and the most important appears pH value. The thermal properties of the microcapsules are explored by differential scanning calorimetry. The optimum conditions are:pH value 1.5, temperature 333.15～363.15 K, mass fraction of NaCl about 10%. The thermal analysis results show that the endothermic ability between 296.26 K and 308.15 K amounts to 9.11 J/g when the microcapsules undergo solid-liquid phase change at 300.53 K, the mean fusion heat of the microcapsule is 1.20 J/(g·K).展开更多
文摘Paraffin microcapsules with urea-formaldehyde polymer skin are prepared by in-situ polymerization of urea-formaldehyde prepolymer. It is found that the pH value of the aqueous solution, addition of NaCl and temperature affect the developing rate of microcapsules, and the most important appears pH value. The thermal properties of the microcapsules are explored by differential scanning calorimetry. The optimum conditions are:pH value 1.5, temperature 333.15～363.15 K, mass fraction of NaCl about 10%. The thermal analysis results show that the endothermic ability between 296.26 K and 308.15 K amounts to 9.11 J/g when the microcapsules undergo solid-liquid phase change at 300.53 K, the mean fusion heat of the microcapsule is 1.20 J/(g·K).
