Dielectric-Barrier Discharges: Their History, Discharge Physics, and Industrial Applications

Dielectric-barrier discharges (silent discharges) are used on a large industrial scale. They combine the advantages of non-equilibrium plasma properties with the ease of atmospheric-pressure operation. A prominent feature is the simple scalability from small laboratory reactors to large industrial installations with megawatt input powers. Efficient and cost-effective all-solid-state power supplies are available. The preferred frequency range lies between 1 kHz and 10 MHz, the preferred pressure range between 10 kPa and 500 kPa. Industrial applications include ozone generation, pollution control, surface treatment, high power CO₂ lasers, ultraviolet excimer lamps, excimer based mercury-free fluorescent lamps, and flat large-area plasma displays. Depending on the application and the operating conditions the discharge can have pronounced filamentary structure or fairly diffuse appearance. History, discharge physics, and plasma chemistry of dielectric-barrier discharges and their applications are discussed in detail.     

Physics of the zero-point field: implications for inertia,gravitation and mass

Previous studies of the physics of a classical electromagnetic zero-point field (ZPF) have implicated it as a possible basis for a number of quantum phenomena. Recent work implies that the ZPF may play an even more significant role as the source of inertia and gravitation of matter. Furthermore, this close link between electromagnetism and inertia suggests that it may be fruitful to investigate to what extent the fundamental physical process of electromagnetic radiation by accelerated charged particles could be interpreted as scattering of ambient ZPF radiation. This could also bear upon the origin of radiation reaction and on the existence of the same Planck function underlying both thermal emission and the acceleration-dependent Davies--Unruh effect. If these findings are substantiated by further investigations, a paradigm shift would be necessitated in physics. An overview of these concepts is presented thereby outlining a research agenda which could ultimately lead to revolutionary technologies.     

An Alchemist in Greenland: Hans Egede (1686–1758) and Alchemical Practice in the Colony of Hope

The article explores the practical and social circumstances of the alchemical experiments performed by the Norwegian priest and missionary Hans Egede (1686–1758) in the Colony of Hope in Greenland. Sources not previously used in connection with Egede’s alchemy are used to investigate in which ways his situation in the colony affected alchemical practice. A lack of fuel is found to have been a main obstacle which may have limited the number of experiments that Egede was able to perform in Greenland. At the same time, the area had natural resources that were useful to the alchemist, and Egede’s position as head of the colony gave access to resources that facilitated alchemical practice.     

Physics of shell assembly: line tension, hole implosion, and closure catastrophe

The self-assembly of perfectly ordered closed shells is a challenging process involved in many biological and nanoscale systems. However, most of the aspects that determine their formation are still unknown. Here we investigate the growth of shells by simulating the assembly of spherical structures made of N identical subunits. Remarkably, we show that the formation and energetics of partially assembled shells are dominated by an effective line-tension that can be described in simple thermodynamic terms. In addition, we unveil two mechanisms that can prevent the correct formation of defect-free structures: "hole implosion," which leads to a premature closure of the shell; and "closure catastrophe," which causes a dramatic production of structural disorder during the later stages of the growth of big shells.     

技能形成、技能形成体制及其经济社会学的研究展望

逆全球化回潮意味着全球生产价值链条秩序的重新洗牌,对于中国制造而言,依赖比较优势的传统发展模式面临着前所未有的挑战,其突出表现就是基于低技能、低成本的经济发展方式与社会平等之间的矛盾日益尖锐。在发达资本主义国家从劳动密集型迈向技术密集型发展方式的转型过程中,国家技能形成体制起到了最为核心的作用,成为其重要的比较制度优势。国家技能形成体制分为国家主义、市场主义、集体主义、以及分隔主义四种制度模式。这四种制度模式具有不同的制度特性,同时也会导致不同的经济社会后果。中国的国家技能形成体制呈现出明显的碎片化,其间的制度冲突已成为阻碍中国技能生产、劳工保护乃至国家制造业创新能力提升的深层制度根源。从人力资本形成走向技能形成、分析技术流动的社会断裂现象成为经济社会学相关领域研究的一个新增长点。     

Department of Physics,Shaoxing College of Arts and Sciences,Shaoxing 312000

A simplified method, Laplace transformation, is used to discuss the radial Schrodinger equation with the weakest bound electron potential model (WBEPM). Through using such method, the second-order differential equation is reduced to a first-order differential equation and the exact bound state solutions including energy spectrum and normalized wave functions are obtained by making use of the integral. The results agree with those obtained by Zheng. It is most important that the two kinds of new recursion relations of radial wave functions are derived by the same method. These new recursion relations are the relations between the effective principal and angular-momentum quantum numbers, and are comprehensive in application to the calculations of transition probabilities in atomic and molecular physics.