水辅助注塑大直径介质导管制品的冷却分析

采用数学分析方法 ,通过假设、简化分析模型 ,用数学模型来表述物理模型 ,确定了水辅助注塑(WAIM )大直径介质导管制品的冷却时间 ,并运用算例和国外试验的结果进行验证。结果发现 :水辅助注射成型新工艺可以更加显著地缩短注塑周期 ,降低制件壁厚 ,允许制件有更大的实际直径。因此 ,WAIM技术可用来高效率地生产大直径、高质量、薄壁的介质导管。

水辅助注射成型技术

水辅助注射成型是IKV公司在通过对气体辅助注射成型技术和设备改进的基础上,开发成功的一种新技术,该技术可用于生产棒状或管状空心制品。水辅助注射成型技术在注射期间,水的前沿象柱塞一样作用在制品的熔融芯上,从水的前沿到熔体的过渡段,固化一层很薄的塑料膜,就象高粘度的型芯,进一步推动聚合物熔体。

Noradrenaline as a putative neurotransmitter mediating hypotension-induced Fos-like immunoreactivity inthe supraoptic nucleus of the rat

Hemorrhage or hypotension induces extensive Foslike immunoreactivity in the magnocellular neurosecretory cells in the supraoptic nucleus of the hypothalamus in rat, especially in the vasopressin neurons. The present study was to explore the neurotransmitter mediating this effect. Microinfusion of the alpha-adrenergic blocker into the supraoptic nucleus reduced the hypotension-induced Fos, whereas beta-antagonist did not affect it significantly. Alpha1- and alpha2-antagonist, prazosin and yohimbine,both reduced the Fos-positive cell counts. However, the effective dosage of yohimbine was much larger. Alpha1-agonist, methoxamine, induced abundant Fos-like immnnoreactivity in the vasopressin cells in this nucleus,while beta-and alpha2-agonist did not elicit such effect.Administration of the noradrenergic re-uptake inhibitor,desipramine, to this nucleus to locally accumulate the spontaneously released noradrenaline from the nerve terminals also induced Fos expression, mostly in the vasopressin cells.