The Tianjing huowen 天経或問 of You Yi 游藝 (fl. 17C.) is a book on natural philosophy, composed under strong influence from the scholarly circle led by Fang Yizhi 方以智 (1611-1671) in the Jiangnan region. Although this book is known to have been more widely distributed in Japan than in China, no extensive survey of its textual exemplars has so far been carried out. Based on a survey of existing printed editions and manuscripts of the book, this paper seeks 1) to specify the most important exemplars useful for restoring the text of the book, and 2) to clarify the aspects of this bookʼs textual production and circulation, especially in Japan, where the majority of surviving exemplars are found.
In early 1950s USAEC launched the strategic step of R&D named “Power Reactor Demonstration Program” in the nuclear power reactors development. The purpose of the program was to enlist private resources to demonstrate the technical and economic feasibility of power reactors. In this program, the light water reactors established a basic design concept in a short development period, but it was economically unsuccessful. After that, reactor manufacturers were able to make light water reactors successful products by pursuing economic efficiency by means of increasing the scale and the power density of reactors, though these reactors were technologically unmature. Such procedure of the development led to weakness of the reactors in safety, that is, core melting due to loss of cooling function.