HOCO+ toward the Galactic Center

We have identified a weak thermal line U42.767, which has been detected only in the directions toward Sgr A and Sgr B2, as the HOCO+ 2_{02}--1_{01} transition. Because of the proximity of this line to the SiO maser line at 42.821 GHz (J=1-0 v=2),it was observable simultaneously in the ~43 GHz SiO maser searches at Nobeyama. From the past data of SiO maser surveys of infrared objects in the Galactic center, we created a map of emission distribution of HOCO+ in the Sgr A molecular cloud as well as maps of the 29SiO J=1-0 v=0 thermal emission and H53alpha emission. The emission distribution of HOCO+ was quite similar to the distribution of 29SiO emission. It suggests that the enhancement of the HOCO+ abundance in the galactic center is induced by shock activities which release the CO2 molecules frozen on grains into gases.Comment: PASJ Dec. 25, 2006 issue in pres

SIZE EFFECTS ON MAGNETIC PROPERTY AND CRYSTAL STRUCTURE OF MN3O4 NANOPARTICLES IN MESOPOROUS SILICA

Mn3O4 nanoparticles with particle sizes of 7.8, 11.4, and 18.3 nm were synthesized in the pores of mesoporous silica, and their crystal structure and magnetic properties were investigated. The powder X-ray diffractions at room temperature indicated that the crystal structural symmetry was the same as that for bulk crystal, and the lattice constants deviated from those for bulk crystal, which depended on the particle size. In addition, compared with the bulk crystal, the Jahn-Teller distortion for the nanoparticles was suppressed and decreased with decreasing the particle size. The coercive field for 7.8 nm was rather smaller than those for 11.4 and 18.3 nm. The nanoparticles with 11.4 and 18.3 nm exhibited pronounced three kinds of magnetic transition temperatures, whereas the susceptibility for 7.8 nm indicated the existence of two transition temperatures. These experimental results suggested that the Mn3O4 nanoparticles have a strong correlation between crystallographic structure and magnetic property, and the characteristic magnetic size effects are attributed to the reduction of Jahn-Teller distortion.The 21st International Conference on Magnetism (ICM2018), July 15-20, 2018, San Francisco, US

SiO Maser Survey of the Inner Bar of the Galactic Bulge

We surveyed 291 MSX/2MASS infrared objects in the 7 x 2 deg area of the galactic center in the 43 GHz SiO J=1--0 v=1 and 2 maser lines, obtaining accurate radial velocities of 163 detected objects. The surveyed area is the region where the IRAS catalog is incomplete due to contamination by high source density. The objects in the present MSX/2MASS sample were chosen to have similar infrared characteristics to those of the previous SiO-maser-survey samples based on the color selected IRAS sources. The sampling based on the 2MASS catalog causes a bias to the foreside objects of the bulge due to heavy obscuration by interstellar dust; the detections are considerably leaned on the V_{lsr}<0 side. The l--v diagram reveals two conspicuous features, which were not present or tenuous in the previous studies: one feature indicating a linear velocity increase with longitude with |l|<1.5 deg, which is likely associated with the inner bar, and the other feature having considerably eccentric velocities more than those of the normal x_1-orbit family feature. The extinction-corrected K magnitudes (if used as a distance modulus) tend to show a sequential deposition of these objects along the line of sight toward the Galactic center depending on their radial velocities. The tendency that appeared in the distance measures is consistent with the bulge-bar dynamical model utilizing the periodic orbit families in the bar potential.Comment: Full high resolution figures available as NRO report No.638 at http://www.nro.nao.ac.jp/library/report/list.html. PASJ 58, No. 3 (June 25 issue in press

Characteristic Size Effects on the Crystallographic Structure and Magnetic Properties of RMnO3 (R = Eu, Gd, Tb, Dy) Nanoparticles

We synthesized lanthanoid manganese oxide RMnO3 (R = Eu, Gd, Tb, and Dy) nanoparticles with particle sizes ranging from approximately 6.5 to 23 nm and investigated both their crystal structure and magnetic properties. The RMnO3 nanoparticles showed a strong correlation between crystal structure and magnetic properties, and particle size effects on these properties vary owing to the different atomic radii of the lanthanoid ions. The magnetic properties of all of the nanoparticles exhibited significant changes as the lattice constants changed at characteristic sizes that depend on the lanthanoid ionic radius; however, the characteristic size for magnetic properties corresponded to the magnitude of the orthorhombic distortion b/a = 1.10, regardless of the lanthanoid ionic radius. With decreasing particle size, EuMnO3, GdMnO3, and TbMnO3 nanoparticles induced tensile strain of MnO6 octahedra, whereas compressive strain occurred in DyMnO3 nanoparticles. The deformation of MnO6 octahedra changed the magnetic interactions, resulting in changes in the magnetic properties. As the particle size decreased, for R = Eu, Gd, and Tb, the magnetic properties, such as transition temperature, coercive field, and blocking temperature, decreased; conversely, these values increased in DyMnO3. The distortion of the unit cell induced changes in the magnetic ordering state due to decreasing particle size

Synthesis and Magnetic Property of Multiferroic BiMnO3 Nanoparticles in the Pores of Mesoporous Silica

The mesoporous silica material SBA-15 was prepared with control pore size for use as a nanoparticle synthesis template. The X-ray diffraction results show that the nanopores were ordered in a hexagonal structure. The pore size was controlled by the synthesis conditions. Nanoparticles of the multiferroic compound BiMnO3 with an average size of about 14 nm were successfully synthesized in the pores of SBA-15, and their magnetic properties were investigated. The prepared BiMnO3 nanoparticles showed both antiferromagnetic and ferromagnetic behavior, whereas BiMnO3 bulk crystals consistently showed ferromagnetic behavior. The prepared BiMnO3 nanoparticles exhibited unique magnetic size effects: the appearance of antiferromagnetic behavior and the coexistence of antiferromagnetic and ferromagnetic components

Anisotropic compression effects on nanocrystalline crystals of nickel oxide

Nickel oxide (NiO) with bulk crystalline size is an antiferromagnetic insulator correlated strongly with crystal structure. A reduction in crystalline size causes a change in the magnetic sublattice, resulting in the appearance of ferromagnetic moments. Furthermore, in the nano crystals fabricated in mesoporous silica, there is a lattice distortion at the unit cell level that brings about the change in the magnetic property, suggesting a prominent magneto-structural correlation. We investigate anisotropic compression effects on nanocrystalline NiO with a crystalline size (D) of 11.4 nm to observe this remarkable magneto-structural correlation. Magneto-crystalline anisotropy is at its maximum when negative contraction occurs. The negative contraction appears even in a bulk crystal under non-ideal hydrostatic compression, and its anomalous structural change is suppressed with decreasing D

Stability Testing of Drug Products Approved by the Japanese Government in 2015

2015年に日本で承認された新医療用製剤に対し、安定性試験の現状を調査した。我々は、2015年に安定性試験の記述がある81の新医療用製剤を特定した。長期保存試験としては、5製剤が30±2℃/65±5％相対湿度の条件下で、55製剤が25±2℃/60±5％相対湿度の条件下で、21製剤が5±3℃の条件下で試験が実施されていた。また、加速性試験では、60製剤が40±2℃/75±5％相対湿度の条件下で実施されていた。17製剤は25±2℃/60±5％相対湿度の条件下で実施された。3製剤は温度及び試験期間がマスキングされていて、不明であった。1製剤は半減期が短いため、加速試験は実施されなかった｡これらの結果から、2015年に日本で承認された新医療用製剤は、1つを除いて ICH ガイドラインに従って、適正に承認されていることがわかった