Performance of a lithium fluoride bolometer for Tokyo dark matter search experiment     

Wataru Ootani  Makoto Minowa  Takayuki Watanabe  Yutaka Ito  Yasuhiro Kishimoto  Kentaro Miuchi  Yoshizumi Inoue  Youiti Ootuka 《Astroparticle Physics》1998,9(4):325-329

The performance of a 21-g lithium fluoride bolometer is presented. The background spectrum was measured in the surface laboratory. We derive an exclusion plot for the spin-dependent coupled Weakly Interacting Massive Particles (WIMPs) cross section.  相似文献   

“Extreme boiling” model for variable salinity of the Hokko low-sulfidation epithermal Au prospect, southwestern Hokkaido, Japan   总被引：1，自引：0，他引：1  

A.-M. Scott  Y. Watanabe 《Mineralium Deposita》1998,33(6):568-578

The Hokko prospect is located in the Minamikayabe area southwestern Hokkaido, Japan, where gold-bearing quartz veins of Pliocene age are exposed at the surface. The alteration mineral assemblage is typical of low-sulfidation epithermal systems, with the quartz veins associated with adularia alteration overprinted on Late Miocene propylitic alteration. Fluid inclusion studies of the vein quartz reveal mean homogenization temperatures of approximately 220 °C, and the co-existence of low-salinity (<2 wt.% NaCl equivalent) and moderate salinity (2 to 12 wt.% NaCl equivalent) fluid inclusions within the same veins. The moderate salinity fluid inclusions (2–12 wt.% NaCl equivalent) typically have relatively low homogenization temperatures between 150° to 200 °C. The results obtained from stable isotope analysis of  δ¹⁸O in quartz vein material showed a gradual decrease in  δ¹⁸O signatures with increasing depth. The majority of the samples have calculated fluid source signatures (δ¹⁸O_H2O) between −8.0 and −10.0‰, but there is a significant change in the composition above 185 m drill depth. The shallower samples in particular show a wide range of oxygen isotope signatures that are associated with the moderate salinity fluid inclusions. We interpret that low-salinity inclusions within the Hokko system represent the composition of the liquid phase of the fluid, before boiling, and that the moderate-salinity inclusions are representative of the residual liquid phase, after extensive non-adiabatic boiling and vapor loss in an open system. This mechanism resulted in the entrapment of fluids with variable salinities at the same time, and in close proximity to each other. This is also reflected in the  δ¹⁸O_H2O values which become more variable and heavier where the moderate-salinity inclusions occur. Deposition of ore minerals within the Hokko vein system also occurred at this time as a result of boiling and gas loss. Received: 30 May 1997 / Accepted: 6 January 1998  相似文献   

High temperature heating of the Allende meteorite     

Kenji Notsu  Naoki Onuma  Norimasa Nishida  Hiroshi Nagasawa 《Geochimica et cosmochimica acta》1978,42(6):903-907

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Mode of eruption of Miyake-jima volcano in historic times     

Naoki Isshiki 《Bulletin of Volcanology》1964,27(1):29-48

Miyake-jima, an island volcano, resting on the Izu-Mariana arc is a basaltic stratovolcano dotted with many parasitic cones and craters. Literatures tell us thirteen eruptions which took place in A.D. 1085, 1154, 1469, 1535, 1595, 1643, 1712–1714, 1763–1769, 1811, 1835, 1874, 1940 and 1962. The last two eruptions were studied in detail by using modern scientific techniques after the surface activities had almost died down. Of the thirteen eruptions, the earlier five are only described as «eruption» and no detailed accounts are written in a document. The eruptions in and after 1643 all occurred from parasitic craters or fissure vents and are classified into the following two types:

1. 1)
   Eruption from a center or centers on or around a parasitic knob on the southwestern flank of the main stratovolcano. Examples are eruptions of 1643, 1712–1714, 1763–1769 and 1835.  相似文献