Preparing For Hyperseed MAC: An Observing Campaign To Monitor The Entry Of The Genesis Sample Return Capsule

The imminent return of the Genesis Sample Return Capsule (SRC) from the Earth’s L1 point on September 8, 2004, represents the first opportunity since the Apollo era to study the atmospheric entry of a meter-sized body at or above the Earth’s escape speed. Until now, reentry heating models are based on only one successful reentry with an instrumented vehicle at higher than escape speed, the 22 May 1965 NASA “FIRE 2” experiment. In preparation of an instrumented airborne and ground-based observing campaign, we examined the expected bolide radiation for the reentry of the Genesis SRC. We find that the expected emission spectrum consists mostly of blackbody emission from the SRC surface (T∼ ∼2630 K@peak heating), slightly skewed in shape because of a range of surface temperatures. At high enough spectral resolution, shock emission from nitrogen and oxygen atoms, as well as the first positive and first negative bands of N₂⁺, will stand out above this continuum. Carbon atom lines and the 389-nm CN band emission may also be detected, as well as the mid-IR 4.6-μm CO band. The ablation rate can be studied from the signature of trace sodium in the heat shield material, calibrated by the total amount of matter lost from the recovered shield. A pristine collection of the heat shield would also permit the sampling of products of ablation.     

Anatomy of individual agglutinates from a lunar highland soil

Abstract— We report results of our investigation of the relationship between values of I_s/FeO (relative concentration of nanophase Fe⁰ divided by total FeO content), glass abundance, total Fe content, and degree of digestion of <20 μm clasts for 22 individual agglutinates (250–1000 μm) from the mature Apollo 16 soil 61181 (I_s/FeO = 82 units in the <250 μm fraction). Agglutinates are important products of space weathering on the Moon, and they influence spectral observations at visible and near-IR wavelengths. Values of I_s/FeO for individual agglutinates (250–1000 μm) within this single soil span a range from 3 to 262 units which is larger than the range observed for all Apollo 16 bulk soils (～0 to 110 units). No correlation was observed between I_s/FeO and glass abundance and FeO concentrations for either agglutinitic glass or whole agglutinate particles under investigation. Our results suggest that the variation in I_s/FeO for agglutinates from a single soil may be in part a consequence of natural mixing processes on the Moon that produce highly-variable environments (with respect to surface exposure) for agglutinate formation and in part to variable kinetics of reactions in an agglutinate melt, which are influenced by a variety of factors including melt composition, temperature, impactor velocity, and quench rate. We cannot exclude but do not see evidence for other processes including addition of exotic agglutinates, micrometeoritic bombardment into compositionally-diverse microtargets, recycling of agglutinates, preferential melting of very fine soil particles, and production of nanophase Fe⁰ in amorphous rims of very fine irradiated lunar grains contributing to the observed variation of I_s/FeO.     

Diamond Discovered in Dangqiong Ophiolite, Western Yarlung-Zangbu Suture Zone, Tibet

<正>The first diamonds from ophiolite were found in peridotite of Luobusa ophiolite along Yarlung Zangbu suture zone in Tibet,China(IGCAGS,1981),and then more and more diamonds found in harzgurgite(Bai et al.,1993;Yang et al.,2007a;Robinson et al.,2014;Xu et al.,     

Diopside and Magnetite Exsolutions in Olivine from Lower Cr# Dunite in the Dongbo Ophiolite, Southern Tibet

<正>Diopside and magnetite exsolutions occur as oriented intergrowths within olivine of the lower Cr~#dunite in the Dongbo ophiolite,Tibet.The fresh lower Cr~#dunite has a mineral assemblage of olivine,spinel and diopside.The Fo content of its olivine is 90–92,which is lower than that of the higher Cr~#dunite lenses(Fo92-Fo94)without     

Composition and Textual Characterization of Platinum-group Mineral (PGM) in Chromites from Zedang Ophiolite in Tibet, China

<正>1 Introduction Platinum-group elements(PGE)are mainly concentrated in some specific minerals known as PGMs,which commonly occur in podiform chromites of ophiolites.In-situ PGM assemblages in chromites can provide valuable information on the physico-chemical nature of the parental melt(s)from which chromitite     

The pre-Landnám fauna of Iceland: a palaeontological contribution

The origins of the Icelandic biota are discussed with particular reference to recent work on Coleopteran (beetle) and Trichopteran (caddis fly) fossils from deposits which are earlier than the arrival of man (Landnám) in the country. The hypothesis of survival through Pleistocene glaciations in refugia is discounted in favour of immigration on ice floes during Late Glacial/Early Holocene deglaciation. Consideration of the nature of the insect fauna and the extent of Late Glacial ice sheets, with the evidence from ocean circulation patterns, suggests a source area in the fjords of south-west Norway. The model is applicable to the origins of the biota on all the North Atlantic islands, east of the Davis Strait.     

PRINCIPAL COMPONENTS REGRESSION FOR ROUTINE MULTICOMPONENT UV DETERMINATIONS: A VALIDATION PROTOCOL

A validation protocol for multicomponent spectroscopic assays based on principal componentsregression is described. Factorial design and hypothesis tests are used to establish the linearity andabsence of interaction between components in the regression model. Testing considers multiple responsevariables simultaneously so that correlation between residuals is properly treated. Assay reproducibilityand sensitivity to related substances are evaluated.     

MIXTURE ANGLYSIS USING FACTOR ANGLYSIS I: CALIBRATION AND QUANTITATION

One of the major application areas of factor analysis, multivariate calibration and quantitation, is coveredin this review. The algorithms, methodologies and applications covered include principal componentregression, target transformation factor analysis, singular value decomposition and rank annihilationfactor analysis. Many important areas of research having relevance to multivariate calibration andquantitation problems are also covered in this review, including background correction, measurementerror, rank determination, cross-validation, figures of merit, detection of invalid samples, experimentaldesign, sample selection, statistical inference and wavelength selection.