Melting curve of methane was measured up to 4.8GPa and 260°C using a diamond anvil type high pressure-temperature apparatus. Pressure and temperature in the sample chamber were measured from the wavelength and the line width of the fluorescence line emitted from a ruby chip placed in the sample chamber. This melting curve provides important constraint on the evolution of the icy satellites.
When a molybdenite was dissolved and treated by the conventional chemical procedure, it was difficult to achieve the isotopic equilibrium between the 187Os radiogenically accumulated in the molybdenite and“common”Os added as a kind of internal standard, even after chemically complete decomposition. It is evident that this isotopic disequilibrium effect results in deterioration of Re-Os age for the molybdenite. A newly developed analytical technique employing a microwave digestion was found out to promote the isotopic equilibration of Os from two sources and to provide us with the ages concordant with those obtained by other geochronometers.
A novel in vitro method for maintaining the physiological activities of late gestation rat fetuses was developed. The uterus with fetuses was isolated from a pregnant rat and was perfused with a physiological solution through a cannula inserted into uterine artery. With this transplacental-perfusion method, it became possible to maintain the activities of the heart and the central nervous system of late gestation rat fetuses (E14-E21) for more than 24 hours in vitro. The present method may be useful for a variety of studies on mammalian fetal development, enabling direct observation and manipulation of late gestation fetuses.