Iterative method and apparatus for x-ray computed tomographic fluoroscopy
    91.
    发明授权
    Iterative method and apparatus for x-ray computed tomographic fluoroscopy 有权
    x射线计算机断层摄影术的迭代方法和装置

    公开(公告)号:US06101236A

    公开(公告)日:2000-08-08

    申请号:US165370

    申请日:1998-10-02

    IPC分类号: G06T11/00 A61B6/03

    摘要: In the present invention, an iterative process is provided for computed tomographic fluoroscopy (CTF) based upon an ordered-subset based algorithm or an adaptation of the row-action expectation maximization (RAEM) formula. This process is applied to reduce metal artifacts in CTF imaging, reduce image noise and provide rapid-image updating suitable for real-time applications. In one embodiment, generation of a projection mask and computation of a relaxation matrix are used to compensate for beam divergence and data incompleteness, and a priori knowledge such as a known image support is used to reduce image reconstruction errors.

    摘要翻译: 在本发明中,基于有序子集的算法或行行为期望最大化(RAEM)公式的适应性,提供了用于计算机断层摄影术透视(CTF)的迭代过程。 该过程应用于减少CTF成像中的金属伪影,降低图像噪声,并提供适合实时应用的快速图像更新。 在一个实施例中,使用投影掩模的生成和松弛矩阵的计算来补偿光束发散和数据不完整性,并且使用诸如已知图像支持的先验知识来减少图像重建误差。

    Method of depositing chromium and silicon on a metal to form a diffusion
coating
    92.
    发明授权
    Method of depositing chromium and silicon on a metal to form a diffusion coating 失效
    在金属上沉积铬和硅以形成扩散涂层的方法。

    公开(公告)号:US5492727A

    公开(公告)日:1996-02-20

    申请号:US240350

    申请日:1994-05-10

    IPC分类号: C23C10/54 C23C16/00

    CPC分类号: C23C10/54

    摘要: A method for the simultaneous deposition of chromium and silicon to form a diffusion coating on a workpiece uses a halide-activated cementation pack with a dual halide activator. Elemental metal powders may be employed with the dual activator. A two-step heating schedule prevents blocking a chromium carbide from forming at the surface of the workpiece. Small contents of either Ce or V can be added to the Cr+Si contents of the coating by introducing oxides of Ce or V into the filler of the pack.

    摘要翻译: 用于同时沉积铬和硅以在工件上形成扩散涂层的方法使用具有双卤化物活化剂的卤化物活化胶结包装。 元素金属粉末可与双重活化剂一起使用。 两步加热程序可防止在工件表面形成碳化铬。 可以通过将Ce或V的氧化物引入包装的填料中,将Ce或V的少量添加到涂层的Cr + Si含量中。