Effects of Zirconium Doping Into a Monoclinic Scheelite BiVO4 Crystal on Its Structural, Photocatalytic, and Photoelectrochemical Properties

Effects of zirconium (Zr) doping into BiVO4 powder on its structural properties and photocatalytic activity for O2 evolution were examined. The formation of BiVO4 powder crystallized in a monoclinic scheelite structure (ms-BiVO4) was achieved when the sample was doped with a relatively small amount of Zr. The photocatalytic activity of Zr-doped ms-BiVO4 powder was much higher than that of non-doped ms-BiVO4. However, further doping caused a reduction of photocatalytic activity for O2 evolution due to the occurrence of structural alterations into tetragonal scheelite and tetragonal zircon structures. Similar effects of Zr doping were also observed for the photoelectrochemical (PEC) system based on BiVO4 thin films doped with various amounts of Zr. Thus, Zr doping was confirmed to be effective for improvements of photocatalytic and PEC functions of BiVO4 for water oxidation

Non-linear Mining of Social Activities in Tensor Streams

Web検索履歴等に代表される大規模時系列データは，時刻や地域，キーワードといった様々な情報とともに収集され，テンソルストリームとして扱うことができる．Web上におけるユーザアクティビティの解析では，より高精度な将来予測を実現することが重要な課題の1つであるが，複雑な構造を持つテンソルストリームから将来予測に有用なパターンを発見することが問題となる．本論文では，時間，国，キーワードの3つ組に対するWeb検索数で構成されるテンソルストリームを効果的に解析するためのストリームアルゴリズムであるCUBECASTを提案する．CUBECASTは与えられたテンソルストリームに含まれる潜在的な長期トレンドと季節パターンを発見し，それらを基に類似した特徴を持つ地域グループへと分解する．このとき，提案手法は次の特長を持つ．(a)長期トレンドと季節パターンの非線形特性を単一のモデルで表現する．(b)パラメータチューニングや事前知識を必要とせず，時系列モデルやパターン変化を自動的に推定する．(c)逐次的かつ適応的にパターン変化をとらえ，テンソルストリームを効率的に処理する．実データを用いた実験では，提案手法が将来予測に有用なパターンを効果的かつ効率的に発見できることを示し，既存の時系列予測手法と比較して，予測精度，計算時間の改善を確認した．Given a large time-evolving event series such as Google web-search logs, which are collected according to various aspects, i.e., timestamps, locations and keywords, how accurately can we forecast their future activities? How can we reveal significant patterns that allow us to long-term forecast from such complex tensor streams? In this paper, we propose a streaming method, namely, CUBECAST, that is designed to capture basic trends and seasonality in tensor streams and extract temporal and multi-dimensional relationships between such dynamics. Our proposed method has the following properties: (a) it is effective: it finds both trends and seasonality and summarizes their dynamics into simultaneous non-linear latent space. (b) it is automatic: it automatically recognizes and models such structural patterns without any parameter tuning or prior information. (c) it is scalable: it incrementally and adaptively detects shifting points of patterns for a semi-infinite collection of tensor streams. Extensive experiments that we conducted on real datasets demonstrate that our algorithm can effectively and efficiently find meaningful patterns for generating future values, and outperforms the state-of-the-art algorithms for time series forecasting in terms of forecasting accuracy and computational time

水の光電気化学的酸化分解に活性な BiVO4薄膜光電極への Zr 添加効果

Effects of zirconium (Zr) doping into BiVO4 electrode on its structural properties and photoelectrochemical (PEC) property for water oxidation were examined. The BiVO4 electrodes with different Zr contents were prepared via a spin-coating process. Structural analyses using XRD and Raman spectroscopy indicated that all the samples consisted of mixtures of monoclinic scheelite (ms-BiVO4) and tetragonal scheelite (ts-BiVO4) structures. The highest PEC property for water oxidation was achieved when the sample doped with a relatively small amount of Zr (i.e., 0.5% of Zr-doped BiVO4); further doping caused a reduction of PEC property, probably due to the enhancement of carrier recombination induced by such excess Zr components

Desorption of excimers from the surface of solid Ne by low-energy electron or photon impact

If a solid Ne surface is irradiated by 20–200 eV electrons or by 55–75 nm synchrotron radiation, Ne 2 * excimers in a 3 Σ u state are desorbed to form a luminescent “plume” in front of the sample. The kinetic energy of the desorbed excimers was found to be (0.2±0.1)eV, which indicates that the cavity ejection mechanism is valid for the excimer desorption. The decay with time of the plume emission is not of single exponential type, because the emission lifetime of the desorbed excimers, which is of the order of 10 -6 s, depends on their vibrational level. Most of them are in the highest vibrational level since desorption takes place much faster than vibrational relaxation

The Use of Fitness Testing to Predict Occupational Performance in Tactical Personnel: A Critical Review

Tactical personnel work in an occupation that involves tasks requiring a high level of cardiovascular fitness as well as muscular strength and endurance. The aim of this literature review was to identify and critique studies investigating the relationship between physical fitness, quantified by fitness assessment measures, and occupational task performance. Databases were searched for relevant articles which assessed a fitness measure and a measure of occupational performance. A total of 15 articles were included and were deemed to be of acceptable methodological quality (8.4/12 on the Critical Appraisal Skills Programme checklist). Included articles assessed a variety of fitness attributes and occupational tasks. Across tactical groups, there appear to be no standardized fitness tests that can determine occupational performance, with aerobic fitness, anaerobic fitness, strength, endurance, power, and agility all being associated with occupational task performance. A wide range of fitness assessments appears to be required to predict occupational performance within tactical personnel. Efforts should be made to base fitness assessments on occupational demands unique to both the environment and requirements of each individual tactical unit