Based on the characteristics of double cavitycentral venous catheters, Selected the suitable extruding process, and designed the extruding die.
前言： 根据双腔中心静脉导管的特点，选择了合适的导管成型工艺，并设计了挤出机机头的芯模和口模。
2
An external layer of compact Bone surrounds a central area of spongy Bone, except at the marrow cavity.
骨的外层为质密的骨皮质，包围着海绵状骨松质中心区（不算骨髓腔）。
3
Purpose: To search the value of central venous catheter in the diagnosis and treatment which was placed in serous membrane cavity for the treatment of malignant fluid.