ニホン ニ テイチャク シタ トガリアメンボ ノ シュウネン ケイカ ト ラン キュウミン

トガリアメンボは和歌山県北部および大阪府南部において卵態で越冬することを明らかにした。当該地域において, 本種の成虫は一般に6月上旬から11月下旬まで水面上で活動し, 10月以降には休眠卵を産出した。野外で越冬した卵の孵化時期は不斉一であり, 翌年の4月下旬から5月中旬に孵化した。休眠卵は1か月以上の5℃暴露および2時間の-5℃暴露に耐性を有していた。非休眠卵の卵期間は20℃で約27日, 25℃で約19日, 28℃で約15日であり, 発育は斉一であった。幼虫期間は日長と無関係で, 20℃で約62日, 25℃で約38日, 28℃で約32日であった。有翅型成虫は6月から11月まで出現した。野外における本種の産卵基質には水面上に浮遊する植物片が利用されており, 樹皮断片, および長さ35mm以下で直径2～4mm の枝片に特に多く産卵されることが明らかになった。また, 室内では, 一部の卵は産卵基質に挿入されず水中に放出された。これらにも正常に発育して水中から孵化するもののあることを認めた。In northern Wakayama and southern Osaka areas on Honshu Island, it was confirmed that the waterstrider Rhagadotarsus kraepelini Breddin overwinters as eggs. Adults generally appeared on ponds from early June to late November. Alate adults were observed from June through to November, and diapausing eggs were produced from October onwards. Hatching of these diapausing eggs under field conditions occurred between late April and mid-May of the following year. Diapausing eggs that were exposed to 5℃ for 41 days and then chilled to -5℃ for a further 2 hours were able to complete their hatching when returned to an incubation temperature of 25℃. Duration from oviposition to hatching in non-diapausing eggs was approximately 27 days when incubated at 20℃, 19 days at 25℃, and 15 days at 28℃. Developmental times in nymphs decreased as incubation temperatures increased, and were unaffected by photoperiod. In field populations, floating plant materials such as bits of bark and short twigs were used as ovipositional substances. In laboratory rearing trials, a small proportion of eggs were also deposited in the water and had become fixed to the bottom of the container. Some of these eggs successfully hatched

Dependence of Activity of Rutile Titanium(IV) Oxide Powder for Photocatalytic Overall Water Splitting on Structural Properties

Rutile TiO2 powder having a band gap of 3.0 eV was studied as a photocatalyst for overall water splitting with respect to structural properties. The structures of rutile TiO2 samples were characterized by means of X-ray diffraction, scanning electron microscopy, photoacoustic spectroscopy, and a photoelectrochemical technique. It was found that rutile TiO2 particles that are photocatalytically active for the reaction exhibit a lower density of surface trapping states that slow water oxidation kinetics, as well as spatially separated reduction/oxidation sites at exposed crystal faces. This study also demonstrated that the photocatalytic activity of rutile TiO2 for overall water splitting, even when the material was well crystallized, was sensitive to defects that exist in (or near) the surface rather than in the bulk crystal