Study on acoustical physical constants of ZnO single crystal using the ultrasonic microspectroscopy technology

2008 IEEE International Ultrasonics Symposium Proceeding

Depletion of CCS in a Candidate Warm-Carbon-Chain-Chemistry Source L483

We have carried out an observation of the CCS ($J_{N}$=2$_{1}-$1$_{0}$) line with the Very Large Array in its D-configuration toward a protostellar core L483 (IRAS~18140$-$0440). This is a candidate source of the newly found carbon-chain rich environment called "Warm-Carbon-Chain-Chemistry (WCCC)", according to the previous observations of carbon-chain molecules. The CCS distribution in L483 is found to consist of two clumps aligned in the northwest-southeast direction, well tracing the CCS ridge observed with the single-dish radio telescope. The most remarkable feature is that CCS is depleted at the core center. Such a CCS distribution with the central hole is consistent with those of previously observed prestellar and protostellar cores, but it is rather unexpected for L483. This is because the distribution of CS, which is usually similar to that of CCS, is centrally peaked. Our results imply that the CCS ($J_{N}$=2$_{1}-$1$_{0}$) line would selectively trace the outer cold envelope in the chemically less evolved phase that is seriously resolved out with the interferometric observation. Thus, it is most likely that the high abundance of CCS in L483 relative to the other WCCC sources is not due to the activity of the protostar, although it would be related to its younger chemical evolutionary stage, or a short timescale of the prestellar phase.Comment: 10 pages, 3 figures, accepted for publication in ApJ Part

Morphology and Anatomy of Holocene Raised Coral Reef Terraces in Kodakara Island, Tokara Islands, northwestern Pacific, Japan

Well-developed Holocene raised coral reef terraces are formed in Kodakara Island (29°13'N 129°19'E), Tokara Islands, northwestern Pacific, Japan. Detailed morphology and sedimentary structure of the raised reef terraces are observed by field survey through the terraces surface and core drillings. The Holocene raised reef in Kodakara Island are divided into three terraces (TI to III). The surface geo-biological facies and paleo-morphology such as spur and groove system or reef mounds are well preserved on these terraces. The raised coral reefs in Kodakara Island consist of reef flats and reef slopes. No lagoon formed in these terraces. On the raised reef surface, we observed five distinct reefal facies (S-f1-5). The platy and encrusting Acropora facies is the major constituent of the terrace surfaces. We obtained seven drilling cores (B1 to 7) from Terraces I and II along a transect in the southern part of the island. The thickness of the Holocene reef is more than 14m which is approximately equivalent to the Holocene reefs in the middle and southern Ryukyu Islands. Sedimentary structure consists of seven facies (C-f1-7: five reefal and two non-reefal facies). The drilling cores indicating the shallowing sequence at the upward of the cores which characterized by platy-encrusting Acropora facies overlying massive Porites, favid and/or encrusting-foliaceous coral facies. It may indicate the environmental change such as wave-energy gradients and turbidity during the reef development

Bilayer Indium Tin Oxide Electrodes for Deformation-Free Ultrathin Flexible Perovskite Solar Cells

The superior electrical conductivity and optical transparency of indium tin oxide (ITO) make it an ideal electrode material for use in optoelectronic devices such as solar cells. When ITO electrodes are fabricated on very thin plastic substrates, however, the internal stress of the ITO layer causes the substrate to deform, severely limiting the device's performance. Herein, it is shown that ITO bilayers composed of an amorphous base layer and a crystalline overlayer lead to deformation-free ITO electrodes. It is shown that an optimized bilayer structure is achieved when the internal stresses of the amorphous and crystalline layers approximately cancel. With this approach, mixed composition metal halide perovskite solar cells with ITO electrodes are successfully fabricated on 4 μm polyethylene naphthalate films. A power conversion efficiency (PCE) of 18.2% is obtained for the reference cell design, corresponding to a power-to-weight ratio of 24 W g−1 before encapsulation. The devices retain 95% of the original PCE after 1000 bend cycles, while under simulated indoor lighting (white LED, 200 lux, 5000 K) the PCE reaches 28.3%. A 3-cell module with a designated area of 2.3 cm² is realized with a power output of 28.1 mW and an open-circuit voltage of 3.17 V

Drilling Research of a high-latiude coral reef in Mage Island, Stsunan Islands, Japan

Four drilling cores are observed from a high-latitude coral reef at the northwestern Mage Island (N30゜45' 40"). The thickness of the Holocene reef is around 2.5m in the reef edge and 4m in back reef. The Holocene thickness is relatively thin comparing to the modern reefs in the middle or the southern Ryukyu Islands. The reef structure Acropora facies, reworked coral rubble facies. This zonal structure conforms to the ecological coral-zonation corresponding to the wave-energy gradient