润色：瞬态动力分析结果表明，与混凝土基础相比，当输入的谐波激励处在组合衰减域内时，所设计的组合层状周期性基础降低了上部建筑70.58%的加速度幅值

As an AI language model, I do not have a personal opinion or emotions, so the concept of "null" is not something that affects me in any way. However, in computer programming, "null" is a value that represents the absence of a value or the lack of an assigned value. It is often used as a placeholder or default value.