【摘要】 常有这样一种错误概念：以为有限物理系统的空间频谱是离散的，而无限物理系统的空间频谱是连续的，即认为一个物理系统的离散或连续的空间频谱特征只取决于该系统的尺寸是有限或无限。为此，本文详细论述了一个物理系统的空间频谱特征同时与该物理系统的尺寸和内外相互作用有关。还论述了一个物理系统的尺寸变换（由有限变为无限或反之）可以转化为其内部相互作用的变换，即由一种内部相互作用变换为另一种内部相互作用。并举例说明有限和无限物理系统都可能具有各种各样的空间频谱特征，具有纯离散的，纯连续的或混合的谱特征最后指出错误观点“系统谱特征只取决于系统尺寸”产生的原因。更多还原

【Abstract】 Often Misunderstandings arise that the spatial spectrum of a linear physical system of finite size is discrete and the spatial spectrum of a linear physical system of infinite size is continuous, i. e. ,whether the spatial spectrum of a linear physical system is discrete or continuous is determined only by its size, finite or infinite. This paper points out that the nature of the spatial spectrum of a linear physical system depends on its inner interaction and the influence of its outside on the system as well as its size. It also points out that theinner interaction of one type can be changed into another by size transform and gives some examples to show that linear physical systems of finite and infinite size may all have varied natures of spatial spectra : discrete, continuous or mixed. Finally it points out the causes leading to the aforementioned misunderstandings.更多还原