口径比

不改变燃烧室体积，通过改变燃烧室的口径比和径深比，对柴油机工作过程进行了模拟计算。燃烧模型取4步简化动力学模型，湍流模型取修正k-ε模型。

The working process of diesel engine is simulated by changing flow field , surface-volume ratio , diameter-depth ratio of combustion chamber with the same volume .

老根由外向内依次为：周皮、次生韧皮部、形成层、次生木质部、初生木质部。在根中五叶木通木质部导管口径比三叶木通的大很多。

While for older roots , there are periderm , secondary phloem , cambium , secondary xylem and primary xylem . In root , the duct caliber of xylem in Akebia quinata ( Thunb . ) Decne .

对带有二次喷射导向壁面的小口径比和小径深比的ω型燃烧室，充分利用活塞顶面以上氧气的问题仍有待解决。

The ω - combustion chamber with small caliber ratio , small surface-volume ratio and leading wall of secondary spray is not very well to make use of oxygen above piston surface and in the upper portion of combustion chamber .

当喷射高度和喷嘴口径之比大于1时，流场的沿壁射流区厚度会急剧地减小，电场强度降低，从而提高铸斑的定域性。

When jet height is less than jet diameter , electric field strength will be decreased and locality will be improved .

本文就加工－精度要求高，且口径厚度比为35：1的薄形零件，设计了多种加工及上下盘方法，并用激光平面干涉仪测试加工过程，从而加工出高质量的零件。

To make a high accuracy thin plate with the ratio between diameter and thickness , 35:1 , various fabricating and blocking methods are designed and the process of fabricating is checked by a laser flat interferometer .

研究表明：口径为正方形时辐射能量较小；而对长方形口径，当脉冲极化方向与其短边平行时，辐射能量最大；在口径面积相同的条件下，多口径辐射的能量比单口径小。

The energy radiation will attain the maximum while the polarization of incident wave is parallel to the short side of a rectangular aperture . The energy radiated from the multi an aperture is less than that from a single aperture provided their apertures area being the same .