If you need to stop working on a mail merge you can save the envelope main document and resume the merge later .

如果您需要停止 使用邮件合并，可以先保存 信封主文档，然后在以后恢复合并。

The working principle of this system is that an image of grinding wheel envelope profile shot by CCD camera is transported into the computer then the image is treated by Matlab finally the geometrical parameters of the grinding wheel envelope profile is outputted .

该系统的 工作原理是采用高精度的CCD相机摄取样板上的砂轮 包络廓形图像，并将其传入计算机，计算机通过应用软件Matlab对图像进行处理，最终输出砂轮包络廓形的几何参数。

If you want to include a return address on the envelopes you can set this up before you start working on the envelope main document .

如果希望在信封上包含寄信人地址，可以在开始 处理 信封主文档之前完成此设置。

I get the working space of parallel mechanism by surface envelope principle .

通过曲面 包络原理求得并联机构的 工作空间。