Synthesis and Magnetic Properties of Fergusonite Structured La(NbVMn)O4

The authors have synthesized fergusonite-structured La(Nb0·71V0·04Mn0·25)O4 samples. The samples, consisting of La3+, Nb5+, V5+, Mn4+ and oxygen ions, demonstrated temperature-dependent magnetization that increased with lowering the temperature below ≈200 K, and almost saturated below ≈100 K. At 75 K, the field-dependent magnetization demonstrated sigmoidal curve and reached 3 μB/Mn at 1 T. Such a magnetic behavior can be ascribed to exchange interaction between Mn4+Nb2O11 nanoclusters. The Mn4+ substitution for the V5+ sites of the crystal resulted also in the occupied state above the valence band maximum

Low-temperature solution-processable Ni(OH)2 ultrathin nanosheet/N-graphene nanohybrids for high-performance supercapacitor electrodes

A novel and facile strategy is developed to fabricate highly nitrogen-doped graphene (N-graphene) based layered, quasi-two-dimensional nanohybrids with ultrathin nanosheet nanocrystals using a low-temperature, solution processing method for high-performance supercapacitor electrodes. High N doping can be achieved together with one of the lowest oxygen content in chemically reduced graphene and related nanohybrids at low temperature by large-scale residue defects of chemically reduced graphene. The layered, quasi-two-dimensional nanohybrids or heterostructures of ultrathin Ni(OH)2 nanosheet nanocrystal/N-graphene can be applied in supercapacitor electrodes with ultrahigh capacitances of ∼1551 F g-1, excellent rate performance in the scan measurements (from 2 mV s-1 to 100 mV s-1) and in the discharge tests (from 1.5 A g-1 to 30 A g-1) and good cycling stability. Moreover, the capacitance of Ni(OH)2 nanosheet/N-graphene nanohybrids is two and one orders of magnitude higher than that for pure nanocrystals and for the physical mixture of nanocrystal/N- graphene, respectively. Electron transfer in supercapacitor electrodes based on nanohybrids is over 100 times faster than that in electrodes from pure nanocrystals and several tens of times faster than that in electrodes from nanocrystal/N-graphene mixtures. This low-temperature method may provide a low-cost, solution-processable and easily scalable route to high-performance graphene nanohybrid electrodes for energy applications. © 2014 the Partner Organisations

A novel Ti-based nanoglass composite with submicron–nanometer-sized hierarchical structures to modulate osteoblast behaviors

Owing to recent progress in nanotechnology, the ability to tune the surface properties of metals has opened an avenue for creating a new generation of biomaterials. Here we demonstrate the successful development of a novel Ti-based nanoglass composite with submicron–nanometer-sized hierarchical glassy structures. A first exploratory study was performed on the application of the unique nanostructure to modulate osteoblast behaviors. Our results show that this Ti-based nanoglass composite, relative to conventional metallic glasses, exhibits significantly improved biocompatibility. In fact, a 10 times enhancement in cell proliferation has been achieved. To a great extent, this superior bioactivity (such as enhanced cell proliferation and osteogenic phenotype) is promoted by its unique hierarchical structures combining nanoglobules and submicron button-like clusters from collective packing of these nanoglobules. This nanoglass composite could be widely applicable for surface modifications by means of coating on various materials including BMGs, crystalline metals or ceramics. Therefore, our successful experimental testing of this nanostructured metallic glass may open the way to new applications in novel biomaterial design for the purpose of bone replacement

Assessment Report of Doctoral Theses

フィプロイン水溶液の構造とダイナミクス[越智]Preparation of carbon anodic materials with high graphitization degree for Li ion secondary battery[梁]沿岸都市域における局地風の特性に関する研究[福田]原子間力顕微鏡による焼もどしマルテンサイトの組織観察法の開発と遅れ破壊特性に優れる組織の解析[早川]核融合炉プラズマ対向機器材料中のトリチウム透過挙動に関する研究[中村]軽水炉におけるジルカロイ燃料被覆管の高燃焼度下腐食加速現象に関する研究[木戸]広い温度範囲における各種熱伝導率測定法の比較と断熱材の熱伝導率および比熱測定に関する研究[大村]水素化精製触媒の反応中堆積物による活性劣化に関する研究[雨宮]過栄養海域の干潟における水質変動に関する研究[児玉]石炭液化大型パイロットプラントにおける閉塞性固形物に関する研究[荒牧]次世代銅製錬法に関する研究[尾島

学位論文審査報告

フィプロイン水溶液の構造とダイナミクス[越智]Preparation of carbon anodic materials with high graphitization degree for Li ion secondary battery[梁]沿岸都市域における局地風の特性に関する研究[福田]原子間力顕微鏡による焼もどしマルテンサイトの組織観察法の開発と遅れ破壊特性に優れる組織の解析[早川]核融合炉プラズマ対向機器材料中のトリチウム透過挙動に関する研究[中村]軽水炉におけるジルカロイ燃料被覆管の高燃焼度下腐食加速現象に関する研究[木戸]広い温度範囲における各種熱伝導率測定法の比較と断熱材の熱伝導率および比熱測定に関する研究[大村]水素化精製触媒の反応中堆積物による活性劣化に関する研究[雨宮]過栄養海域の干潟における水質変動に関する研究[児玉]石炭液化大型パイロットプラントにおける閉塞性固形物に関する研究[荒牧]次世代銅製錬法に関する研究[尾島