摘要：An alluvium with a sandy aquifer at the bottom,but lacking an effective impermeable layer between the sandy aquifer and bedrock is referred to as a special alluvial *** by the drainage of the aquifer due to mining activities,a shaft wall in this special alluvial stratum will be subject to a downward load by an additional vertical force which must be taken into consideration in the design of the shaft *** complexity of interaction between shaft wall and the surrounding walls makes it extremely difficult to determine this additional vertical *** a particular shaft wall in an extra-thick alluvium and assuming that the friction coefficient between shaft wall and stratum does not change with depth,an analysis of a numerical simulation of the stress within the shaft wall has been carried *** and size of the additional vertical stress have been obtained,based on specific values of the friction coefficient,the modulus of elasticity of the drainage layer and the thickness of the drainage ***, the safety of shaft walls with different structural types was studied and a more suitable structural design,providing an important basis for the design of shaft walls,is promoted.

摘要：为满足核电厂设计中对控制棒的要求,对结构改进的大晶粒控制棒吸收体材料银铟镉吸收体棒进行了试制,开展了化学成分分析、晶粒度、物理性能、力学性能和蠕变性能测试,研究了晶粒度及中心开孔对吸收体棒性能的影响.结果表明:试制的银铟镉吸收体棒的化学成分和杂质元素含量满足ASTM标准规定,物理性能与对比材料相当;增大晶粒尺寸能够改善吸收体棒的导热系数和蠕变性能,但强度有所降低;中心孔对吸收体棒的力学性能没有影响,预期可以满足核电厂对控制棒高价值和长寿命的要求.

摘要：考虑到再生混凝土微细观结构的非均质性,建立了包括新、旧界面过渡区,新砂浆、旧粘结砂浆和天然骨料的再生混凝土五相模型。基于Monte Carlo理论,借助MATLAB软件平台开发了更贴近实际的再生混凝土凸多边形粗骨料分析模型。模型计算结果与试验结果相近,证明五相凸骨料细观模型能较好地预测再生混凝土中氯离子的渗透行为,进而定量分析了再生骨料混凝土特性因子对氯离子渗透的影响。研究结果表明:当再生粗骨料体积分数由0增至50%时,氯离子扩散系数和扩散深度分别增加102.0%和23.9%;当界面过渡区厚度从25μm扩大至100μm时,氯离子扩散深度和扩散系数分别增加13%和37.0%;当再生粗骨料含量较大时,旧粘结砂浆的增加会显著降低再生混凝土抗氯离子渗透性能,旧砂浆粘结率从0.1增加到0.4,氯离子扩散系数增加18.2%;新、旧界面过渡区和旧粘结砂浆是影响再生混凝土抗氯离子渗透能力的根本原因。