碳酸镁

Considering to the fatigue calendar characteristics of materials, the sequence effects of loading spectrum and the mechanical behavior of cyclic hardening/softening of metals, the cumulative fatigue damage is proved to have character of Markov process. Also, the distribution of the cumulative fatigue damage and its critical value is deduced to vary with the pre-exposure calendar time of materials.

考虑载荷次序效应、材料循环硬化/软化效应及材料的大气环境腐蚀老化效应，论证了疲劳累积损伤随机过程的Markov性，及疲劳累积损伤的正态分布特性，同时证明了临界累积损伤的统计特性随日历时间的变化关系，在此基础上建立了一新的全动态疲劳累积损伤统计干涉模型。

For distorted book image under random twisted status,by comparing its margin-gray-curve data with the stored margin-gray-curves data,a group of multinomial coefficients whose corresponding twisted status is proximal to that of the to be corrected image can be selected out to determine automatically a group of distortion parameters that is suitable for distortion correction.

任意弯曲状态下的书籍扫描图像可以在数据文件中搜索到与其最接近的弯曲状态，并利用对应的多项式系数自动求得最佳畸变参数，用于图像的畸变校正实验，获得了较好的校正效果，最大误差由未校正时的63%下降到了4.4%。这使得在无需人工测量或调整畸变参数的条件下可自动校正书籍扫描图像。