Lack of exposed ice inside lunar south pole Shackleton Crater   总被引：2，自引：0，他引：2  

Haruyama J  Ohtake M  Matsunaga T  Morota T  Honda C  Yokota Y  Pieters CM  Hara S  Hioki K  Saiki K  Miyamoto H  Iwasaki A  Abe M  Ogawa Y  Takeda H  Shirao M  Yamaji A  Josset JL 《Science (New York, N.Y.)》2008,322(5903):938-939

The inside of Shackleton Crater at the lunar south pole is permanently shadowed; it has been inferred to hold water-ice deposits. The Terrain Camera (TC), a 10-meter-resolution stereo camera onboard the Selenological and Engineering Explorer (SELENE) spacecraft, succeeded in imaging the inside of the crater, which was faintly lit by sunlight scattered from the upper inner wall near the rim. The estimated temperature of the crater floor, based on the crater shape model derived from the TC data, is less than approximately 90 kelvin, cold enough to hold water-ice. However, at the TC's spatial resolution, the derived albedo indicates that exposed relatively pure water-ice deposits are not on the crater floor. Water-ice may be disseminated and mixed with soil over a small percentage of the area or may not exist at all.  相似文献   

Isolation and structure of whiskey polyphenols produced by oxidation of oak wood ellagitannins     

Fujieda M  Tanaka T  Suwa Y  Koshimizu S  Kouno I 《Journal of agricultural and food chemistry》2008,56(16):7305-7310

Three new phenolic compounds named whiskey tannins A and B and carboxyl ellagic acid were isolated from commercial Japanese whiskey, along with gallic acid, ellagic acid, brevifolin carboxylic acid, three galloyl glucoses, a galloyl ester of phenolic glucoside, 2,3-(S)-hexahydroxydiphenoylglucose, and castacrenin B. Whiskey tannins A and B were oxidation products of a major oak wood ellagitannin, castalagin, in which the pyrogallol ring at the glucose C-1 position of castalagin was oxidized to a cyclopentenone moiety. These tannins originated from ellagitannins contained in the oak wood used for barrel production; however, the original oak wood ellagitannins were not detected in the whiskey. To examine whether the whiskey tannins were produced during the charring process of barrel production, pyrolysis products of castalagin were investigated. Dehydrocastalagin and a new phenolcarboxylic acid trislactone having an isocoumarin structure were isolated, along with castacrenin F and ellagic acid. However, whiskey tannins were not detected in the products.  相似文献   

Spatial structures of N₂O, CO₂, and CH₄ fluxes from Acacia mangium plantation soils during a relatively dry season in Indonesia     

Ryota Konda  Seiichi Ohta  Shigehiro Ishizuka  Seiko Arai  Saifuddin Ansori  Nagaharu Tanaka  Arisman Hardjono 《Soil biology & biochemistry》2008,40(12):3021-3030

We investigated spatial structures of N₂O, CO₂, and CH₄ fluxes during a relatively dry season in an Acacia mangium plantation stand in Sumatra, Indonesia. The fluxes and soil properties were measured at 1-m intervals in a 1 × 30-m plot (62 grid points) and at 10-m intervals in a 40 × 100-m plot (55 grid points) at different topographical positions of the upper plateau, slope, and valley bottom in the plantation. Spatial structures of each gas flux and soil property were identified using geostatistical analysis. The means (±SD) of N₂O, CO₂, and CH₄ fluxes in the 10-m grids were 0.54 (±0.33) mg N m⁻² d⁻¹, 2.81 (±0.71) g C m⁻² d⁻¹, and −0.84 (±0.33) mg C m⁻² d⁻¹, respectively. This suggests that A. mangium soils function as a larger source of N₂O than natural forest soils in the adjacent province on Sumatra during the relatively dry season, while CO₂ and CH₄ emissions from the A. mangium soils were less than or consistent with those in the natural forest soils. Multiple spatial dependence of N₂O fluxes within 3.2 m (1-m grids) and 35.0 m (10-m grids), and CO₂ fluxes within 1.8 m (1-m grids) and over 65 m (10-m grids) was detected. From the relationship among N₂O and CO₂ gas fluxes, soil properties, and topographic elements, we suggest that the multiple spatial structures of N₂O and CO₂ fluxes are mainly associated with soil resources such as readily mineralizable carbon and nitrogen in a relatively dry season. The soil resource distributions were probably controlled by the meso- and microtopography. Meanwhile, CH₄ fluxes were spatially independent in the A. mangium soils, and the water-filled pore space appeared to mainly control the spatial distribution of these fluxes.  相似文献   

Determination of Damaged Starch and Diastatic Activity in Wheat Flour Using a Flow-Injection Analysis Biosensor Method     

Ryuichi Haginoya  Kunio Sakai  Takashi Komatsu  Seiichi Nagao  Kenji Yokoyama  Toshifumi Takeuchi  Ritsuko Matsukawa  Isao Karube 《Cereal Chemistry》1997,74(6):745-749

The determination of damaged starch and diastatic activity in flour was studied using a flow-injection analysis (FIA) biosensor system. The system consisted of an oxygen electrode and an immobilized enzyme column containing purified glucoamylase and glucose oxidase immobilized on activated aminopropyl glass beads. The biosensor system has an optimum pH between 6.5 and 7.5 and an optimum temperature of 35°C for glucose measurement. The response of the FIA biosensor was linear up to 1.000 g/L of glucose with a lower detection limit of 0.025 g/L. Each assay took about 20 min, and the system showed good reproducibility (r = 0.998, n = 8). When applied to the measurement of damaged starch and diastatic activity in wheat flour, the results obtained agreed with those obtained using the conventional methods of measurement. This biosensor system is a rapid practical alternative for the measurement of damaged starch and diastatic activity in wheat flour.  相似文献