We have found remarkable ion-conductive properties in a novel polymer electrolyte composed of poly(ethylene carbonate) and Li bis-(fluorosulfonyl) imide. The self-diffusion coefficient of Li-ions exceeded 10(-7) cm(2) s(-1) and the Li transference number was estimated to be more than 0.8 in composites filled with only 1 wt% of TiO2 nanoparticles.

Poly(ethylene carbonate)-based polymer electrolytes with lithium salts (LiX; X = TFSI, ClO 4 , BF 4 and PF 6 ) were prepared, and their lithium transference numbers (t + ) were measured to make comparison between different anion radius and salt concentrations. The LiTFSI electrolytes had the highest t + and Li-ion conductivities of all samples at 80 • C; these values increased with increasing salt concentration. According to the results of FT-IR measurements for all concentrated samples, the changes of band fraction, which divide at around 1720 cm −1 for carbonyl groups interact, with Li + (C=O -Li + ), are strongly related to the mobility of Li + ions. For four decades polymer electrolytes have gained attention as soft ionic materials suitable for novel battery systems such as Li-ion secondary batteries, 1,2 because of their greater safety than liquid electrolytes, their flexibility and their light weight. Unfortunately, the conductivity of typical polyether-based electrolytes such as poly(ethylene oxide) (PEO)-metal salt mixtures is not greater than about 10 −4 S cmat room temperature. 3-5 Moreover, it is extremely difficult to increase the lithium transference number above 0.5.We have recently considered polycarbonates, obtained by the alternating copolymerization of carbon dioxide with epoxides, and potential novel polymers for use as electrolytes.6-8 We focused on the chemical structure of the copolymer, which has a single carbonate group (-O-(C=O)-O-) in each repeating unit of the main chain. Carbonate-based organic solvents are usually used as the electrolyte solution in Li-ion batteries, because of their high dielectric constant. The carbonate group therefore provides a suitable structure for the polymer framework. We reported in our previous studies that a commercial polycarbonate, poly(ethylene carbonate) (PEC) can be used as a novel polymer matrix for the electrolyte, and has extraordinary ion-conductive properties. 9 The ionic conductivity of PEC-Li salt electrolytes increases with increasing salt concentration, whereas the conductivities of typical PEO-based electrolytes are maximum at around 5 mol% and decrease with increasing concentration.9 Moreover, we recently found that the lithium transference numbers (t + ) of PECbased electrolytes are greater than 0.5, and that for their composites filled with small amount of TiO 2 the values are extremely high, more than 0.8. 10 In the present study, we focused on the effect of anions on Li-ion conduction in PEC, and studied t + as a function of anion radius and salt concentration. Interactions between PEC and ions were also studied using FT-IR measurement for the first time. ExperimentalPreparation of PEC-Li salt electrolytes.-Poly(ethylene carbonate) (PEC, M n = 3.7×10 4 ) was donated by a Japanese company. PEC was dissolved as received in chloroform, and the solution was added to excess methanol. The PEC precipitated was dried in a vacuum oven at 60• C for 24 h. The 1 H and 13 C NMR spectra of the purified PEC were observed, and the ratio of the carbona...

The climatological structure of the subpolar cyclonic circulation off East Antarctica is delineated with Argo float data from the past decade. Up to 40% of the float profiles in the seasonal ice zone have been without satellite positioning. We refined their position data as following the bathymetry to get appropriate positions in the continental margin. The error of the terrain‐following interpolation was estimated by using positioned data to be 23 ± 27 (78 ± 70) km for 90 (390) day period. Profiles with the under‐ice period shorter than 360 days are adopted. The float trajectories reveal the extent of the subpolar gyre adjoined to the westward Antarctic Slope Current to its south and the southernmost eastward jet of the Antarctic Circumpolar Current along 4,000 m isobath to its north. The subpolar circulation in the Australian‐Antarctic Basin comprises of a series of quasi‐barotropic subgyre circulations, which are bounded by bathymetric spurs in the continental slope. The temperature field reveals shoreward excursions of Circumpolar Deep Water associated with the subgyres, effectively supplying heat to the continental shelves. An along‐slope temperature variation up to 1°C in 27.7–27.8 kg/m3 σθ indicates an active cross‐slope exchange within the layer. Provided the velocity field and the water mass structure, the subsurface water mass exchange is likely accomplished by a combination of topographically controlled mean flow and the eddy transports. Our findings suggest that the bathymetry primarily determines the structure of the subpolar gyre.

The Antarctic continental margin supplies the densest bottom water to the global abyss. From the late twentieth century, an acceleration in the long-term freshening of Antarctic Bottom Waters (AABW) has been detected in the Australian-Antarctic Basin. Our latest hydrographic observations reveal that, in the late 2010s, the freshening trend has reversed broadly over the continental slope. Near-bottom salinities in 2018–2019 were higher than during 2011–2015. Along 170° E, the salinity increase between 2011 and 2018 was greater than that observed in the west. The layer thickness of the densest AABW increased during the 2010s, suggesting that the Ross Sea Bottom Water intensification was a major source of the salinity increase. Freshwater content on the continental slope decreased at a rate of 58 ± 37 Gt/a in the near-bottom layer. The decadal change is very likely due to changes in Ross Sea shelf water attributable to a decrease in meltwater from West Antarctic ice shelves for the corresponding period.

The southern boundary (SB) of the Antarctic Circumpolar Current, the southernmost extent of the upper overturning circulation, regulates the Antarctic thermal conditions. The SB’s behavior remains unconstrained because it does not have a clear surface signature. Revisited hydrographic data from off East Antarctica indicate full-depth warming from 1996 to 2019, concurrent with an extensive poleward shift of the SB subsurface isotherms (>50 km), which is most prominent at 120°E off the Sabrina Coast. The SB shift is attributable to enhanced upper overturning circulation and a depth-independent frontal shift, generally accounting for 30 and 70%, respectively. Thirty years of oceanographic data corroborate the overall and localized poleward shifts that are likely controlled by continental slope topography. Numerical experiments successfully reproduce this locality and demonstrate its sensitivity to mesoscale processes and wind forcing. The poleward SB shift under intensified westerlies potentially induces multidecadal warming of Antarctic shelf water.

This paper describes deposition of ScAlN thin films by the conventional radio frequency (RF) magnetron sputtering using large size Sc-Al alloy targets with high Sc content. Two 4-in. Sc-Al alloy targets with the Sc content of 43 and 32% were prepared by the sintering method instead of the conventional dissolution method, and deposited film qualities and uniformity were evaluated. In both cases, uniform ScAlN thin films were obtained throughout the three inch wafer. However, measured Sc content was significantly lower than that of the target. Influence of the N 2 content in the sputtering gas was also investigated, and the result indicated that nitridation of the target surface is at least one of the major reasons causing the reduction of the Sc content in the deposited films. We also reports variation in film qualities observed with the accumulated sputtering time.

Melting ice shelves around Antarctica control the massive input of freshwater into the ocean and play an intricate role in global heat redistribution. The Amery Ice Shelf regulates wintertime sea-ice growth and dense shelf water formation. We investigated the role of warm Antarctic Surface Water in ice shelf melting and its impact on dense shelf water. Here we show that the coastal ocean in summer 2016/17 was almost sea-ice free, leading to higher surface water temperatures. The glacial meltwater fraction in surface water was the highest on record, hypothesised to be attributable to anomalous ice shelf melting. The excess heat and freshwater in early 2017 delayed the seasonal evolution of dense shelf water. Focused on ice shelf melting at depth, the importance and impacts of warming surface waters has been overlooked. In a warming climate, increased surface water heating will reduce coastal sea-ice production and potentially Antarctic Bottom Water formation.

To quantitatively assess the inorganic carbon cycle in the eastern Indian sector of the Southern Ocean (80–150°E, south of 60°S), we measured ocean surface temperature, salinity, total alkalinity (TA), the partial pressure of carbon dioxide (pCO2), and concentrations of chlorophyll‐a (chl a), dissolved inorganic carbon (DIC), and nutrients during the KY18 survey (December 2018–January 2019). The sea–air CO2 flux in this region was −8.3 ± 12.7 mmol m−2 day−1 (−92.1 to +10.6 mmol m−2 day−1). The ocean was therefore a weak CO2 sink. Based on the DIC and TA in the temperature minimum layer, we estimated the change of pCO2 from winter to summer (δpCO2) due to changes in water temperature, salinity, and biological activity (photosynthesis). The spatial distribution of pCO2 in the western part (80–110°E) of the study area was mainly driven by biological activity, which decreased pCO2 from December to early January, and in the eastern part (110–150°E) by temperature, which increased pCO2 from January to February. We also examined the changes in the CO2 concentrations (xCO2) over time by comparing data from 1996 with our data (2018–2019). The oceanic and atmospheric xCO2 increased by 23 and 45 ppm in 23 years, respectively. These changes of ocean xCO2 were mainly driven by an increase in CO2 uptake from the atmosphere as a result of the rise in atmospheric xCO2 and increase in biological activity associated with the change in the water‐mass distribution.