Successive phase transitions and phase diagrams of the quasi-two-dimensional triangular antiferromagnet Rb4Mn(MoO4)3

Comprehensive experimental studies by magnetic, thermal and neutron measurements have clarified that Rb4Mn(MoO4)3 is a model system of a quasi-2D triangular Heisenberg antiferromagnet with an easy-axis anisotropy, exhibiting successive transitions across an intermediate collinear phase. As a rare case for geometrically frustrated magnetism, quantitative agreement between experiment and theory is found for complete, anisotropic phase diagrams as well as magnetic properties.Comment: 4 pages, 5 figure

Sr/Ca-Ba/Ca systematics in Antarctic Ca-rich achondrites and their origins

The Ca, Sr and Ba contents of six Antarctic polymict eucrites (Y-74450,Y-75011,Y-75015,ALH-765,ALH-78040 and ALH-78132) and a unique Antarctic achondrite (ALH-77005) have been determined by ICP-OES. When the data are plotted in the Sr/Ca-Ba/Ca diagram which enables us to visualize igneous processes such as partial melting and crystal fractionation, the eucrites fall on a crystal fractionation line defined by a set of typical eucrites and the unique achondrite falls on a partial melting line through chondritic Sr/Ca and Ba/Ca ratios. The results suggest that the eucrites are a series of melts evolved from a primary magma by clinopyroxene and plagioclase fractionation, while the unique achondrite is a residual solid phase derived from a chondritic source material by a largescale partial melting

Rapid Simultaneous 17 Elements Analysis of Some Yamato Meteorites by ICP-OES

Seventeen elements in stone meteorites were determined rapidly and simultaneously by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectroscopy). Five antarctic meteorites were classified by using ICP-OES data. The result is as follows : Yamato-74001 and -75028 are H chondrite and Yamato-74035,-74191 and Allan Hills-769 are L chondrite

Case study: acquisition of Japanese in aural language by the four year old child whose hearing loss was detected when he was visiting in U. S. with his family

Access to thesis is restricted. Contact Archives and Rare Books. This paper reports the results of language training for a newly diagnosed hearing impaired Japanese child using methods from the CID parent-infant program

A Classification of Several Yamato-74 Chondrites

Six Yamato-74 chondritic meteorites have been classified, based on iron contents of olivines and orthopyroxenes in their small fragments. The results are as follows : Yamato-74193,-74498 and -74507 are H4-chondrites, Yamato-74367 and -74603 are L4-chondrites, and Yamato-74454 is L5-chondrite

Oxygen isotopic compositions of petrographically described inclusions from Antarctic unequilibrated ordinary chondrites

Several inclusions from the Antarctic unequilibrated ordinary chondrites (ALH-764 (LL3), ALH-77015 (L3) and Y-790448 (L3)) were excavated and their petrography, chemical and oxygen isotopic compositions were determined. The coherent data indicates that precursors of the ordinary chondrites consist of a mixture of two different solid materials. One is a pre-existing solid enriched in albite component and depleted in ^O component and the other is a solid depleted in albite component and enriched in ^O component. The latter solid material may be an evaporation residue of the former solid material in an ambient gas

Oxygen Isotopes in Several Yamato Meteorites

Oxygen isotopic compositions (^O/^O and ^O/^O) of five Yamato meteorites have revealed that Yamato-7303 (m), -74190,-74191,and -7308 (l), -74013 can be classified as L ordinary chondrites and differentiated meteorites, respectively. The former three meteorites may have been derived from one parent body, and the latter two meteorites are from another parent body in the solar system

Origin and Evolution of Condrules Based on Na/Al-Dispersion and -Convergence in Yamato-74 Ordinary Chondrites

Na/Al convergence has been observed in groundmass of chondrules and matrix from seven Yamato-74 (H, L, 4-5) chondrites. On the other hand, Na/Al dispersion has prevailed in groundmass of chondrules and matrix from Yamato-74191 (L3) chondrite. The results suggest that : (1) Primordial liquid droplets as precursors of the chondrules might be derived from a rapidly cooling solar nebula by fractional condensation. (2) The hot liquid droplets thus formed might be cooled instantaneously by radiation loss in the cooling nebula. (3) The chondrules as quenched products might be subjected to mutual collision during accumulation in the cold nebula. (4) Planetesimals accumulated by the chondrules might be transferred from the place of birth to an unknown hot region in the proto solar nebula

Rb-Sr isotope systematics and Sr/Ca-Ba/Ca ratios at DSDP Hole 89-462A

Four samples of Nauru Basin basalts (Cores 94 to 109 of Hole 462A, sub-bottom depth 1077-1209 m) have 87Sr/86Sr ratios in the range 0.7037 to 0.7038, which is distinctly higher than the ratios of N-type MORB. The Rb contents of the samples are depleted in comparison with those of MORB and ocean-island basalts. These chemical and isotopic characteristics are identical to those of the basalts previously drilled during Leg 61 (Cores 75 to 90 of Hole 462A), and are explained in terms of inhomogeneity of the source region in the mantle or later alteration effects. Sr/Ca-Ba/Ca systematics of 15 samples from Cores 462A-94 to 462A-109 and 14 samples from Cores 462A-75 to 462A-90 suggest that the Nauru Basin basalts are derived from a mantle peridotite by 20 to 30% partial melting with subsequent Plagioclase crystallization

(Table 1) Sr isotopes and chemical composition of DSDP Hole 61-462A basalts

Sixteen elemental abundances and 87Sr/86Sr ratio of the Nauru Basin basalt (Cores 75 to 90: sub-bottom depths 950 m to 1050 m) from Hole 462A have been determined by inductively coupled plasma-optical emission spectroscopy and mass spectrometry. The result indicates that the basalt is a new type of oceanic tholeiite, elementally similar to normal mid-oceanic ridge basalts and isotopically similar to oceanic island-type basalts