positive infinitely variable unit

Digestive tract of Gyllotalpe Unispina Sausure had special histology, there were protruding long crest on all inner wall Of digestive tract and thick short tooth in its cavum oris and pharynx, some compact thin long thom lied on gastric caecus and preventriculus, there are microvilli on its esophagus, crop and postintestine, many blunt thom were on the rectum.

本文采用组织学技术对华北蝼蛄消化道的组织结构进行了研究其消化道具有特殊的组织结构，消化道各部的内壁均有隆起的纵脊；口腔和咽上有较粗的短齿；胃盲囊、前胃上有排列紧密的细长刺：食道、嗉囊及后肠上均有纹状缘：盲肠上生有成群的纯利此项研究为讲一步防治病虫害提供了依据。

The expressions of plane and space conjuration gear forms and meshing line of a single thread twin screw pump are derived on the basis of spatial meshing theory, and the equations for original gear forms and space spiral plane are given.

根据啮合理论推导了ＨＳＢ４００／２型单头双螺杆式油气混输泵的平面和空间共轭齿形型线方程及啮合线方程。

The results show that the inner walls of the esophagus consist of longitudinal ridges, with teeth at the front tip.

结果表明,中华稻蝗食道内壁由纵行脊组成,前端有齿。

This article mainly deals with the teeth s morphological characters of Oxya chinensis inner alimentary canal, which are observed through scanning electron microscope.

本文采用扫描电镜观察了中华稻蝗消化道内壁齿的分布和结构,发现食道的两端有稀少的齿,而嗉囊ZⅡ和ZⅢ区齿粗和长,并且分布在脊的顶端,纵行排列,该区的齿较为密集。

The two members,Ya(牙) and Chi(齿),in the semantic field of tooth in the Chinese documents of Wei-Jin(魏晋) Dynasty was investigated.

"牙齿"是语言中最核心的词之一。

Introduces the control structure and its diagram of numerical control gear shaper based on PLC.

阐述了基于PLC的数控齿条插齿机控制结构,给出了系统结构示意图,并详细介绍了数控齿条插齿中通用性、间隙误差和冲程数等关键控制技术,结合实例对各项技术的应用作了简要分析。

The design of self-lock mechanism in gear and rack;

一种齿轮齿条自锁机构的设计