@article{oai:jaxa.repo.nii.ac.jp:00034844,
 author = {宮川, 行雄 and 深谷, 敏夫 and Miyakawa, Yukio and FUkaya, Toshio},
 issue = {5/6},
 journal = {東京大學理工學研究所報告},
 month = {Sep},
 note = {The sliding friction of jewels was studied under dry and thin-film conditions. The jewels used as the plates were artificial sapphire, ruby, quartz, obsidian and glass. The sliders were prepared from various metals, such as steel, brass, Cu, Al and Sn as well as from the above mentioned jewels. The coefficient of friction varied conspicuously as the hardness of the slider varied. In dry states, artificial sapphire or ruby used as the plate showed the coefficient of friction of about 0.2 for almost all sliders, but about 0.6 for Al and Sn sliders. Quartz, obsidian and glass showed large coefficients of friction ranging from 0.7 to 1.0 when used with sliders of the same jewels as the plates or sliders of steel, Al or Sn, but showed small values of about 0.3 for brass and Cu sliders. Examining the tracks on the plates due to friction, we gave an interpretation to these results. In general, the coefficient of friction dropped to about 0.2 when clock oil, spindle oil or castor oil was used as lubricant., 資料番号: SA3417540000},
 pages = {171--175},
 title = {寳石の摩擦(應用力學)},
 volume = {3},
 year = {1949}
}