Spatiotemporal estimation of nutrient data from the northwest pacific and east asian seas.

Nutrient data obtained from field observations have the potential to enhance our understanding of oceanic biogeochemical cycling and productivity changes. In particular, long-term nutrient data can provide valuable information on the links between climate change and biogeochemical changes. However, unlike other observational variables such as sea surface temperature, nutrient data are limited in terms of their broad-scale observations and automated sensor-based measurements.

Improved Sensing Behaviors in Reduced Graphene Oxide Functionalized with Ni(OH)2 Nanoparticles.

In this paper, we detail improvements in the sensing properties of reduced graphene oxide (RGO), which were achieved through functionalization. The functionalization process utilizes graphene oxide suspensions, generating nanoparticles on the RGO surface mainly comprised of Ni(OH)2 phase. Raman spectra indicate that functionalization increases the degree of disorder in RGOs.

Improvement of Gas Sensing Characteristics by Adding Pt Nanoparticles on ZnO-Branched SnO2 Nanowires.

We coated zinc-oxide (ZnO)-branched tin oxide (SnO2) nanowires with a Pt shell layer via a sputtering method and subsequently annealed the composite to generate Pt nanoparticles. The spillover effect of Pt nanoparticles was expected to play a significant role in enhancing the response. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy revealed that the nanoparticles were comprised of a cubic Pt phase.

Fabrication and characteristics of hexagonal Zn nanowires prepared by heating a mixture of Zn and graphite powders.

We report the fabrication of thin (< 100 nm) hexagonal Zn nanowires in a conventional reactor, by heating a mixture of Zn and graphite powders. By material characterization, the products were identified as one-dimensional nanowires of serpent-like morphology with a hexagonal Zn phase. The main growth mechanism of the Zn nanowires was proposed to be a vapor-solid process, which was corroborated by the absence of any tip catalyst.

Attachment of metal nanoparticles to SnO2 nanowires for enhancement of gas sensing properties.

We fabricated SnO2/cobalt (Co) core-shell nanowires by means of a two-step process, for their application as chemical sensors. For Co-functionalization, we synthesized SnO2-Co core-shell nanowires by the sputtering deposition of Co layers on the surface of networked SnO2 nanowires, subsequently transforming the continuous Co-shell layers into crystalline islands by thermal heating. While scanning electron microscopy (SEM) images of annealed core-shell nanowires exhibited a rough surface, transmission electron microscopy (TEM) images revealed that the roughness is related to the agglomeration of the sputtered Co layer.

Freeze-drying-induced changes in the properties of graphene oxides.

We have characterized and evaluated changes in graphene oxide (GO) induced by means of freeze-drying. In order to evaluate these changes, we investigated the effects of freeze-drying and chemical reduction processes on the structure, morphology, chemical composition, and Raman properties of GO and reduced GO. The freeze-dried GO had a pore structure, maintaining a pored morphology even after thermal annealing.