In order to confirm the existence of an ordering transition in ice VI, an investigation of the thermal expansion was carried out at low temperatures 4.2° K–200° K and high pressure l0.54 kbar. (AIP)
Abstract The R aman spectra of carbonaceous material ( CM ) from 19 metasediment samples collected from six widely separated areas of S outhwest J apan and metamorphosed at temperatures from 165 to 655°C show systematic changes with metamorphic temperature that can be classified into four types: low‐grade CM ( c. 150–280° C ), medium‐grade CM ( c. 280–400°C), high‐grade CM ( c. 400–650°C), and well‐crystallized graphite (> c. 650°C). The Raman spectra of low‐grade CM exhibit features typical of amorphous carbon, in which several disordered bands (D‐band) appear in the first‐order region. In the R aman spectra of medium‐grade CM , the graphite band ( G ‐band) can be recognized and several abrupt changes occur in the trends for several band parameters. The observed changes indicate that CM starts to transform from amorphous carbon to crystallized graphite at around 280°C, and this transformation continues until 400°C. The G ‐band becomes the most prominent peak at high‐grade CM suggesting that the CM structure is close to that of well‐crystallized graphite. In the highest temperature sample of 655°C, the R aman spectra of CM show a strong G ‐band with almost no recognizable D ‐band, implying the CM grain is well‐crystallized graphite. In the R aman spectra of low‐ to medium‐grade CM , comparisons of several band parameters with the known metamorphic temperature show inverse correlations between metamorphic temperature and the full width at half maximum ( FWHM ) of the D 1‐ and D 2‐bands. These correlations are calibrated as new R aman CM geothermometers, applicable in the range of c. 150–400°C. Details of the methodology for peak decomposition of R aman spectra from the low to medium temperature range are also discussed with the aim of establishing a robust and user‐friendly geothermometer.
To improve the fuel efficiency of electric vehicles, it is necessary to reduce the weight of the wireless power transfer coil in the vehicles. Resistance due to the skin effect or the proximity effect increases during wireless power transfer, decreasing the transmission efficiency. This study aims to reduce the weight of the coil by replacing it with an aluminum plate coil, which is easy to manufacture and inexpensive. The weight of the coil was reduced by 3/4 (from 1.9 to 0.44 kg) when compared with copper Litz wire. Furthermore, the AC resistance was reduced by applying magnetic coating to the same coil. Consequently, the transmission efficiency increased from 88.2% to 89.3%, an improvement of 1.1%. The optimal material for magnetic coating was revealed in an analysis.
Measurements of the pressure dependence of the Curie temperatures in ordered FePt and CoPt alloys were made in a high pressure region up to 12 GPa by using a double-stage multianvil apparatus. For both aloys TC decreased almost linearly by applying pressure with a rate of -5. 98 K/GPa for FePt and -6. 54 K/GPa for CoPt. These rates can be explained in accordance with the Heine's law if it is assumed that Tc is inversely proportional to the band-width.
