- 著者
- Katsunori KOSUGE Atsushi YAMAZAKI Atsumu TSUNASHIMA Ryohei OTSUKA
- 出版者
- The Ceramic Society of Japan
- 雑誌
- Journal of the Ceramic Society of Japan (ISSN:09145400)
- 巻号頁・発行日
- vol.100, no.1159, pp.326-331, 1992-03-01 (Released:2010-08-06)
- 参考文献数
- 15
- 被引用文献数
- 32 59
In order to synthesize well-crystallized magadiite and kenyaite as a single phase in a short reaction time, amorphous silica was hydrothermally reacted with alkaline solutions in the temperature range from 150°C to 200°C. From a suspension containing SiO2 and NaOH with molar ratios of H2O/SiO2=18.5 and NaOH/SiO2=0.23, magadiite was formed after a reaction time of 48 h at 150°C or after 18h at 170°C. The formation of Na-kenyaite, however, required 6h at 200°C. Then, KOH and K2CO3 were used to lower the formation temperature of kenyaite. K-kenyaite was synthesized after 16h at 185°C from a suspension with molar ratios of H2O/SiO2=18.5 and KOH/SiO2=0.23. Furthermore, (Na, K)-kenyaite was formed after 48h at 150°C or after 24h at 170°C from suspensions with molar ratios of H2O/SiO2=18.5, NaOH/SiO2=0.23 and NaOH/K2CO3=0.95-23. Magadiite and kenyaite were formed through a difinite induction period after dissolution of amorphous silica.
- 著者
- Mitsuteru Sato Yukihiro Takahashi Makoto Suzuki Atsushi Yamazaki Tomoo Ushio
- 出版者
- 一般社団法人 電気学会
- 雑誌
- 電気学会論文誌A(基礎・材料・共通部門誌) (ISSN:03854205)
- 巻号頁・発行日
- vol.131, no.12, pp.1000-1005, 2011-12-01 (Released:2011-12-01)
- 参考文献数
- 15
- 被引用文献数
- 6 10
Six-channel spectrophotometers (PH) are the science instruments of JEM-GLIMS to measure absolute intensity of the emission originated from lightning discharges and upper atmospheric transient luminous events (TLEs). PH unit-1 (PH-U1) consists of four spectrophotometer channels named from PH1 to PH4, while PH unit-2 (PH-U2) two spectrophotometer channels named PH5 and PH6. Optical filters of these spectrophotometers are selected to detect TLE emission lines of N2 1PG, N2 2PG, N2+ 1NG, and N2 LBH. Since the bandwidth of the optical filter of PH2, 3, 5, and 6 is 10 nm and since PH1 measures NUV emission, photomultiplier tubes with high-voltage converters are used as a photon detector. To the contrary, PH4 uses a photodiode as a photon detector because the pass-band of the optical filter is enough wide to detect transient optical emission. Though PH does not equip spatial resolution, it can acquire light curve data with a high time resolution of 50 μs with a 12-bit resolution. Thus, the combinational analysis of PH data and Lightning and Sprite Imager (LSI) data, it is possible to clarify the relationship between TLEs and their parent lightning discharges, the occurrence condition of TLEs, and the energy of the electrons which excite TLE emission.