著者

菱木 風花

出版者

独立行政法人 国立科学博物館

雑誌

国立科学博物館研究報告E類(理工学) (ISSN:18819095)

巻号頁・発行日

vol.45, pp.1-11, 2022-12-23 (Released:2022-12-27)

参考文献数

40

---

This paper aims to reexamine the theoretical methods employed by the physicist Hantaro Nagaoka (1865–1950) for earthquake studies from the 1900s through the 1920s by conducting an in-depth analysis of his academic papers. He used two theoretical methods for earthquake studies. One used the principle of elasticity studies against the background of the current that succeeded in France in the first half of the 19th century. The other defined potential functions and explained phenomena from continuous equations of the nature of waves against the background of new currents that emerged in Britain or Germany from the mid-19th century onwards. The differences between these methods were not related to his research subjects or the timing of his research activities. He tried to understand and explain local natural disaster phenomena such as earthquakes through both kinds of theoretical methods.

著者

有賀 暢迪

出版者

独立行政法人 国立科学博物館

雑誌

国立科学博物館研究報告E類(理工学) (ISSN:18819095)

巻号頁・発行日

vol.45, pp.13-16, 2022-12-23 (Released:2022-12-27)

参考文献数

2

---

In the summer of 2022, the National Museum of Nature and Science, Tokyo, held a special exhibition “Various Stories from Artifacts of Scientific, Technological, & Natural History.” It was based on a preceding “integrated research” project running from FY2016 through FY2020. The present report provides a brief description of, as a part of the exhibition, the displayed objects that were related to KAMIOKANDE, the large-scale experimental facility best known for neutrino studies. It also mentions other KAMIOKANDE-related materials included in the permanent exhibition.

著者

沓名 貴彦

出版者

独立行政法人 国立科学博物館

雑誌

国立科学博物館研究報告E類(理工学) (ISSN:18819095)

巻号頁・発行日

vol.44, pp.17-27, 2021-12-24 (Released:2023-02-09)

参考文献数

9

---

Iwabitsu Castle Ruins in Higashi-Agatsuma-machi, Agatsuma-gun, Gunma Prefecture, is famous as mountaintop castle built by the Sanada clan in the Sengoku period, Japan. Two crucibles and four copper ingots excavated from the main bailey were investigated by non-destructive analysis using X-ray Radiography and X-ray Fluorescence Spectroscopy (XRF). As a result, we were found that one of the two crucibles was used for melting gold and another for melting bronze. As there were no impurities around the gold particle that could have been derived from gold ore, this consequence indicates that at placer gold was used. And, ingot’s materials were showed that three were bronze and one was pure copper by XRF. Also, adhesion of zinc was detected on all crucibles and one bronze ingot. In the crucible, zinc was attached in dots, and copper was not strongly detected in the same point. On the other hand, bronze ingot was showed that zinc was diffusely adhered. These results are suggested that brass was made from zinc metal or zinc mineral at the metal workshop where crucibles and copper ingots were used at that time. Therefore, we reveal that the existence of metal workshop utilizing gold and copper alloys such as bronze and brass in the main bailey of a mountaintop castle in the Sengoku period, for the first time in Japan.