Objective To discuss the X-ray and biomechanics characteristic of lumbar spondylolisthesis with intact neural arch and analyze the pathological course of degenerate lumbar instability.

目的探讨椎弓完整性滑脱症的X线、生物力学特点与退行性腰椎不稳的病理进程。

The second problem analyzed is seismic reliability of concrete dam, the artificial neural network model of seismic reliability of concrete gravity dam and concrete arch dam is proposed.

第二个分析的问题是混凝土坝的抗震可靠度问题，应用人工神经网络技术建立混凝土重力坝和拱坝的抗震可靠度模型。