Pure X-ray diffraction profiles have been analysed for polyamide 1010 and PA1O1O-BMI system by means of multipeak fitting resolution of X-ray diffraction. The methods of variance and fourth moment have been applied to...Pure X-ray diffraction profiles have been analysed for polyamide 1010 and PA1O1O-BMI system by means of multipeak fitting resolution of X-ray diffraction. The methods of variance and fourth moment have been applied to determine the particle size and strain values for the paracrystalline materials. The results indicated that both variance and fourth moment of X-ray diffraction line profile yielded approximately the same values of the particle size and the strain. The particle sizes of (100) reflection have been found to decrease with increasing BMI content, whereas the strain values increased.展开更多
This paper considers a fault-tolerant decentralized H-infinity control problem for multi-channel linear time-invariant systems. The purpose is to design a decentralized H-infinity output feedback controller to.stabili...This paper considers a fault-tolerant decentralized H-infinity control problem for multi-channel linear time-invariant systems. The purpose is to design a decentralized H-infinity output feedback controller to.stabilize the given system and achieve a certain H-infinity performance requirement both in the normal situation and in the situation where any one of the local controllers fails. The designed problem is reduced to a feasibility problem of a set of bilinear matrix inequalities （BMIs）. An algorithm is proposed to solve the BMIs. First, the normal situation is considered where all the local controllers are functioning. The local controllers are obtained from a standard centralized H-infinity controller by using a homotopy method imposing a structural constraint progressively. Secondly, the above case is extended to the one where any one of the local controllers fails. We again use a homotopy method where the coefficient matrices of the failed controller are decreased progressively to zero. The efficiency of the proposed algorithm is demonstrated by an example.展开更多
为了研究树脂膜溶渗(resin film infusion,RFI)工艺中树脂的浸渍规律,研制高性能复合材料,首先建立了130℃下改性双马来酰亚胺(bism aleimide,BMI)树脂随时间变化的粘度拟合模型,然后采用有限元/控制体法以及相关实验数据,对带加强筋复...为了研究树脂膜溶渗(resin film infusion,RFI)工艺中树脂的浸渍规律,研制高性能复合材料,首先建立了130℃下改性双马来酰亚胺(bism aleimide,BMI)树脂随时间变化的粘度拟合模型,然后采用有限元/控制体法以及相关实验数据,对带加强筋复合材料板在130℃等温下的RFI成型工艺改性BMI树脂浸渍过程进行了数值模拟,预测了树脂浸渍过程前沿位置、压力分布、浸渍时间和树脂浸渍高度。最后通过模拟发现整个树脂浸渍前沿几乎同时向前推进,浸渍过程前期快后期慢,环境压力越大浸渍高度越高,但是浸渍高度有渐近值等现象。展开更多
基金This work was supported by the National Natural Science Foundation of China and by the National Basic Research Project-Macromolecular Condensed State
文摘Pure X-ray diffraction profiles have been analysed for polyamide 1010 and PA1O1O-BMI system by means of multipeak fitting resolution of X-ray diffraction. The methods of variance and fourth moment have been applied to determine the particle size and strain values for the paracrystalline materials. The results indicated that both variance and fourth moment of X-ray diffraction line profile yielded approximately the same values of the particle size and the strain. The particle sizes of (100) reflection have been found to decrease with increasing BMI content, whereas the strain values increased.
基金This work was supported in part by the National Natural Science Foundation of China (No. 60634020)in part by postdoctoral science foundation of China (20060390883).
文摘This paper considers a fault-tolerant decentralized H-infinity control problem for multi-channel linear time-invariant systems. The purpose is to design a decentralized H-infinity output feedback controller to.stabilize the given system and achieve a certain H-infinity performance requirement both in the normal situation and in the situation where any one of the local controllers fails. The designed problem is reduced to a feasibility problem of a set of bilinear matrix inequalities （BMIs）. An algorithm is proposed to solve the BMIs. First, the normal situation is considered where all the local controllers are functioning. The local controllers are obtained from a standard centralized H-infinity controller by using a homotopy method imposing a structural constraint progressively. Secondly, the above case is extended to the one where any one of the local controllers fails. We again use a homotopy method where the coefficient matrices of the failed controller are decreased progressively to zero. The efficiency of the proposed algorithm is demonstrated by an example.
文摘为了研究树脂膜溶渗(resin film infusion,RFI)工艺中树脂的浸渍规律,研制高性能复合材料,首先建立了130℃下改性双马来酰亚胺(bism aleimide,BMI)树脂随时间变化的粘度拟合模型,然后采用有限元/控制体法以及相关实验数据,对带加强筋复合材料板在130℃等温下的RFI成型工艺改性BMI树脂浸渍过程进行了数值模拟,预测了树脂浸渍过程前沿位置、压力分布、浸渍时间和树脂浸渍高度。最后通过模拟发现整个树脂浸渍前沿几乎同时向前推进,浸渍过程前期快后期慢,环境压力越大浸渍高度越高,但是浸渍高度有渐近值等现象。
