Research on a Structure Analysis of Materials with a Maximum Entropy Restoration of Electron Microscope Images.

1.最大熵复原程序的实现：开发了受量子噪声空间随机分布约束的最大熵复原程序，并在PC机上实现。该程序可以直观地显示修复过程中图像的变化，以及改进的ME修复方法与传统的开方约束方法之间的差异。2.弱相物体透射电子显微镜图像的恢复：将改进的运动估计方法应用于铁蛋白颗粒大散焦的电子显微镜图像的解卷。在散焦图像中，由于对比度传递函数(CTF)的严重振荡而使对比度反转而模糊的铁蛋白颗粒的核心被恢复到具有正确对比度的原始尺寸。傅立叶分析表明，即使在零附近也能通过ME恢复的pi相移自动重建散焦图像中的反差频率区。3晶体成像的实现：为了将ME恢复应用于晶体样品，需要通过模拟样品下方的复波函数来计算图像强度，并将图像强度与观测图像进行比较。因此，用C++语言实现了图像模拟程序，并将其整合到ME恢复程序中。模拟结果与标准程序计算结果吻合较好。4.高分辨率晶体图像ME复原方法的发展：现有ME方法由于设计上的缺陷，不能应用于晶体图像。当电子波函数复杂时，只处理实数。为了解决这一问题，该算法被扩展到处理复杂函数。

1.Implementation of Maximum Entropy (ME) Restoration Programs : Computer programs for the ME image restoration constrained by the spatially random distribution of quantum noise were developed and implemented on PCs. The programs allows visualization of changes in the image during the process of restorations and the difference between the modified ME restoration and conventional kai-squared constrained method. It also enables us to study the effect of the ME restoration in the Fourier space.2.Restoration of TEM Images of Weak-phase Objects : The modified ME method was applied to deconvolution of largely defocused TEM images of ferritin particles. The cores of ferritin particles, which were blurred with reversed contrast due to the severely oscillating contrast transfer function (CTF) in the defocused image, are recovered to the original size with the correct contrast. The Fourier analysis showed that the frequency regions of reversed contrast in the defocused image is automatically reconstructed by the phase shift of pi as a result of the ME restoration even around zeros in the CTF.3.Implementation of the Imaging of Crystals : For application of the ME restoration to crystal specimens, simulation of TEM imaging is required to calculate the image intensity from a simulated complex wave function just below the specimen and to compare the image intensity with the observed image. An image simulation program was, therefore, implemented with a C++ language and incorporated into ME restoration programs. The results of the simulation were in good agreement with those calculated with a standard program.4.Development of ME Restoration of High-resolution Crystal Images : Existing ME methods cannot be applied to crystal images since they are designed. to treat only real number while the electron wave function is complex. To solve this problem, the algorism was extended to deal with complex function.