三角网格曲面等参数线刀轨生成算法

提出一种三角网格曲面等参数线刀轨生成算法。采用调和映射的方法对三角网格曲面进行参数化,给出了四种等参数线刀轨规划方式;根据网格模型、投影网格和参数网格之间的对应关系,由残留高度确定参数网格中的x或r参数线;在此基础上,采用"区域划分"的方法快速生成了无干涉、无冗余数据的网格曲面等参数线行切和环切刀轨。实验结果表明该算法是可行和有效的。

凹型加肋锥-环-柱结合壳局部加强方式的研究

为了给潜艇加肋锥-环-柱结合壳提供设计依据,对组合壳中凹环壳块的加强方式进行了探讨.通过分析凹型加肋锥-环-柱结合壳中环壳块的应力,指出凹环壳块需局部加强的必要性.提出凹环壳块中部增设肋骨和凹环壳块适当加厚两种加强方式,分析它们的应力分布特点.通过大量的计算,比较两种加强方式的效率,提出"应力放大系数"作为衡量凹环壳块加强方式效率的指标.制作了2种加强方式的凹型加肋锥-环-柱结合壳精车模型,进行了模型试验.计算分析和模型试验结果表明,对凹环壳块适当加厚是提高凹型加肋锥-环-柱结合壳效率的较优越的加强方式.

The antinociceptive role of central arginine vasopressin is involved in the endogenous opiate peptide, serotonin and acetylcholine systems

Our previous work has demonstrated that arginine vasopressin (AVP) plays a role in pain modulation. The present study investigated which kinds of neuropeptides and neurotransmitters in central nervous system might be involved in AVP antinociceptive role in the rat. The results showed that (1) intraventricular injection (icv) of V1 receptor antagonist [d(CH2)5Tyr(Me)AVP] and V2 receptor antagonist [d(CH2)5[D-Ile2, Ile4, Ala9-NH2]AVP] blocked the antinociceptive effect induced by AVP (icv), (2) the opiate recaptor antagonist (naloxone) reversed the antinociceptive effect induced by AVP (icv), and (3) both the serotonin receptor antagonist (cypoheptadine) and M receptor antagonist (atropine) could attenuate the antinociceptive effect induced by AVP (icv);but (4) oxytocin, dopamine, N-methyl-D-aspartate (NMDA), γ-aminobutyric acid (GABA), N, α or β receptor antagonist did not influence the antinociceptive effect induced by AVP (icv). The data suggested that AVP antinociceptive role was involved in the endogenous opiate peptide, serotonin and acetylcholine systems in central nervous system.