Self-Organization and the Physics of Entropy Expulsion

这项研究的最终目的是建立自然界中如何自发地创造秩序的普遍概念，即自组织。到目前为止，我们广泛的模拟研究使我们提出了一个场景，即自组织有三个关键过程。首先是系统的内在非线性，其次是从外部世界提供能量(信息)的过程，第三是产生的多余量(熵)从系统中排出的过程。在本研究中，重点研究了产生的熵是限制在系统内部还是从系统中排出的差异对自组织的影响。这是通过以离子-声波双层形成为例来实现的，在这种形成中，热电子以低于电子热速度的相对速度向低温离子流动。为此，建立了一个开放边界粒子模拟模型，其中具有平缓形状分布的新鲜粒子被连续提供，而系统内部产生的脏粒子在边界处被过滤以保持净通量常数。研究发现，与先前周期的短寿命的弱的短寿命势结构相比，系统产生了具有极长寿命的巨大的类似冲击波的无碰撞势结构。与传统的弱(正常)离子-声双层相比，这种巨大的势能结构被命名为“超”离子-声双层。这一新发现得出的结论是，正如我们所断言的那样，当熵被驱逐时，自组织可以非常有力地发生。换句话说，本研究无疑促进了我们假设的自组织情景的发展。

The ultimate goal of this research is to establish the universal concept of how an orderliness is spontaneously created in nature, namely, self-organization. Our extensive simulation studies so far have led us to propose a scenario that there are three key processes in self-organization. The first is the intrinsic nonlinearity of a system, the second is the process of energy (information) supply from the external world, and the third is the process of expulsion of produced superfluous quantities (entropy) from the system.In this research particular emphasis is placed on investigating how the self-organization is influenced by the difference of whether the produced entropy is confined within the system or expulsed from it. This is done by taking as an example the ion-acoustic double layr formation, where hot electrons are streaming relatively to low temperature ions with a relative speed less than the electron thermal speed. For this purpose an open boundary particle simulation model is developed where fresh particles with a gently-shaped distribution are continuously supplied and dirty particles produced inside the system are filtered out at the boundaries so as to maintain a net flux constant.It is discovered that gigantic shock-like collisionless potential structure is created with an extreamly long lifetime, in contrast to a weak, short-lived potential structure in the previous periodic, thus, entropy-reseved system. This gigantic potential structure is named as "super" ion-acoustic double layr compared to the conventional weak ("normal") ion-acoustic double layr. This new discovery concludes that, as we assert, when entropy is expelled, self-organization can take place much vigorously. In other words, the present research has definitely contributed a big step forward to promoting our hypothesized scenario of self-organization.