Prediction method of sand-movement direction in water by geochemical elements

The analysis of sand samples by x-ray fluorescent spectroscopy (XRF) gives the ratio of the geochemical elements to construct the sand samples. The x-ray analysis therefore shows the geochemical characteristics of sand in the sampled area. In this study, sand is sampled on coasts and rivers of the Noto Peninsula to determine the geochemical elements and to show the geological characteristics that occur, especially iron and calcium. The experiments show the effect of rivers and Kotogahama beach on iron and calcium, respectively. Applying the method of ratio matching to the measured data of the geochemical elements, the direction of movement of sand on the coast is determined by considering the correlation matrix and the ratio of geochemical elements between sand samples at two locations. The predominant longshore direction movement of sand offshore in the study area is from south to north. Sand in rivers is not directly transported to adjacent beaches; however, offshore sand is transported to beaches. The estimated direction of movement of sand longshore near coastal structures agrees with observations. The proposed method to predict the direction of movement of sand gives the correct one in comparison with the observed data in rivers.     

橄榄石中H的结合机制及扩散行为

名义上无水矿物(nominally anhydrous minerals,NAMs)中以点缺陷形式存在的结构水,因其对于矿物物理化学性质的显著影响而受到越来越广泛的关注。橄榄石是上地幔中含量最丰富的矿物,水在橄榄石中的存在形式、扩散机制和速率对上地幔的流变学和电导性质有着重要的影响。因此,对于橄榄石中H的结合机制及其扩散机制和速率的了解有助于理解地球深部的水循环,也有助于构建上地幔流变结构以及解释电导测量结果。本文总结了近几十年来学界对于H在橄榄石中存在的缺陷类型与OH红外光谱吸收峰之间的对应关系,以及H在矿物晶格中的扩散机制、扩散速率等重要问题的研究成果,并探讨了现有研究中依然存在的问题。     

The project “spice”

Proposed to both the French and the European Space Agency as one possible small mission, SPICE is a project for a dedicated small satellite for a near-IR spectroscopic all-sky survey. The instrument would cover the spectral range 1.8 - 3.6µm, possibly extended to 1.8 - 7µm, at a resolution of 100, with pixels of 1 arc-min. The excellent sensitivity (0.02 MJy sr-1) results from: i) the quasi-zero level of background due to the efficient passive cooling of the whole experiment; ii) the use of large format arrays; iii) the non-stop observing mode (drift-scanning). The spectral domain, complementing the one of ISO, partially opaque from the ground, is specially rich in spectral features tracing stars and all components of the Interstellar Medium (molecular, atomic and ionized gas, dust). With a cooling below 80 K of the focal instrument, then it becomes possible to consider doubling the spectral domain and to cover the whole 1.8 - 7µm range.     

The C1XS X-ray Spectrometer on Chandrayaan-1

The Chandrayaan-1 X-ray Spectrometer (C1XS) is a compact X-ray spectrometer for the Indian Space Research Organisation (ISRO) Chandrayaan-1 lunar mission. It exploits heritage from the D-CIXS instrument on ESA's SMART-1 mission. As a result of detailed developments to all aspects of the design, its performance as measured in the laboratory greatly surpasses that of D-CIXS. In comparison with SMART-1, Chandrayaan-1 is a science-oriented rather than a technology mission, leading to far more favourable conditions for science measurements. C1XS is designed to measure absolute and relative abundances of major rock-forming elements (principally Mg, Al, Si, Ca and Fe) in the lunar crust with spatial resolution ?25 FWHM km, and to achieve relative elemental abundances of better than 10%.     

Spectroscopic evolution of nova LW serpentis 1978 during its early decline

Optical spectroscopic data are presented on nova LW Serpentis 1978, obtained during its decline fromV 9.0 to ≃10.2 (compared to a value of ∼ 8.0 at recorded maximum). The spectrum and its evolution compare well with a typical nova, though the principal absorption (∼ −750 km s^−l) was very weak in comparison with the diffuse-enhanced absorption (∼ −1300 km s⁻¹). The principal absorption could be identified only in the lines of O I λλ7774, 8446, and in moderate-resolution observations of Hα. The salient features of spectral evolution follow: The near-infrared triplet of Ca n continuously weakened. O I λ8446 was always brighter than O I λ 7774, indicating continued importance of Lyman Β fluorescence. The lines due to [O I], [N II] and N n brightened considerably near the end of our observations (37 days from maximum). The Hα emission line was asymmetric all through with more emission towards the red. Its emission profile showed considerable structure. Based on the individual peaks in the Hα line profile, a kinematical model is proposed for the shell of LW Ser. The model consists of an equatorial ring, and a polar cone on the side away from the earth. The nearer polar cone did not show significant emission of Hα during our observations. The polar axis of the shell is inclined at a small angle (∼ 15‡) to the line of sight.     

Geochemical analyses of geological layers and groundwater flows

X-ray fluorescent spectroscope analysis easily finds ratios of geochemical elements in soil. Applying the method of ratio matching to measured ratios, the classification of geological layers, and the flow directions of groundwater can be determined. This method is applied to three hill slopes in Japan and the results are in good agreement with the observations and measurements of soil cores obtained by drilling. The classification of geological layers is found to be quantitatively connected with the rates of organic matter in soil cores. Received: 5 February 1999 · Accepted: 7 September 1999     

A new occurrence of retrogressed eclogite from the Sanbagawa belt of southwest Japan and its significance

The present paper reports, for the first time, the occurrence of an omphacite‐bearing mafic schist from the Asemi‐gawa region of the Sanbagawa belt (southwest Japan). The mafic schist occurs as thin layers within pelitic schist of the albite–biotite zone. Omphacite in the mafic schist only occurs as inclusions in garnet, and albite is the major Na phase in the matrix, suggesting that the mafic schist represents highly retrogressed eclogite. Garnet grains in the sample show prograde‐type compositional zoning with no textural or compositional break, and contain mineral inclusions of omphacite, quartz, glaucophane, barroisite/hornblende, epidote and titanite. In addition to the petrographic observations, Raman spectroscopy and focused ion beam system–transmission electron microscope analyses were used for identification of omphacite in the sample. The omphacite in the sample shows a strong Raman peak at 678 cm^?1, and concomitant Raman peaks are all consistent with those of the reference omphacite Raman spectrum. The selected area electron diffraction pattern of the omphacite is compatible with the common P2/n omphacite structure. Quartz inclusions in the mafic schist preserve high residual pressure values of Δω₁ > 8.5 cm^?1, corresponding to the eclogite facies conditions. The combination of Raman geothermobarometries and garnet–clinopyroxene geothermometry gives peak pressure–temperature (P–T) conditions of 1.7–2.0 GPa and 440–540 °C for the mafic schist. The peak P–T values are comparable to those of the schistose eclogitic rocks in other Sanbagawa eclogite units of Shikoku. These findings along with previous age constraints suggest that most of the Sanbagawa schistose eclogites and associated metasedimentary rocks share similar simple P–T histories along the Late Cretaceous subduction zone.     

国内外钼资源供需形势分析

全面、系统地建立钼矿石、钼矿粉分析方法,对钼元素研究开发和保障钼矿工业发展具有重要意义。目前多采用酸溶或碱熔样品后进行分析,其不足是测定钼含量的范围窄,消耗样品量大,还需使用大量酸碱,且受仪器限制,分析高含量钼时多需对样品溶液进行数次稀释,使分析步骤更加繁琐。发射光谱法则可避免上述问题,但用之准确分析高含量钼矿石钼矿粉尚有测试方法的瓶颈需要突破。本文研究通过内标元素、分析线对、缓冲剂配比、电流程序等环节的实验分析,建立了固体进样-交流电弧发射光谱法测定钼矿石中高含量钼的分析方法：优化样品与光谱缓冲剂质量比至1∶2,优化分析线对,截取曝光时间35s,采用以国家一级合成硅酸盐光谱分析标准物质和国家一级矿石标准物质组成的自研标准系列制作标准曲线,由全谱交直流电弧发射光谱仪自动扣除分析线和内标线背景后以对数坐标二次曲线拟合计算,使测定范围扩展为500～500800μg/g,检出限为27.38μg/g,相对标准偏差（RSD）为3.28%～8.30%,相对误差为-0.43%～0.73%。结果表明,本文方法在实现绿色分析的同时,在检出限相当、精密度合格的条件下,一次性分析高含量钼的上限从5%提高至50%。

     

Ultra-Deep Optical Spectroscopy with PMAS. Using the Nod-and-Shuffle Technique

PMAS, the Potsdam Multi-Aperture Spectrophotometer, is a new integral field spectrograph in the optical, which is optimized for good transmission and high image quality from 350 nm to 1 μm. We present our plan to implement a CCD charge-shuffle mode to allow for beam switching with a very high degree of sky subtraction accuracy for faint object 3-D spectroscopy. This revised version was published online in July 2006 with corrections to the Cover Date.     

A SIMPLE SOIL MOISTURE INDEX TO FORECAST CROP YIELDS

Neutron probe soil moisture measurements obtained biweekly during the growing season between 1982 and 1991 from multiple depths under grass-covered plots at 17 Illinois Climate Network sites are used to forecast crop yields. A Soil Moisture Index (SMIX) that combines the effect of intensity, duration, and timing of drought or excessively wet conditions was computed by integrating the quantity of available soil moisture throughout the rooting zone over the growing season. Relationships between the SMIX values and crop yields are evaluated at county, regional, and statewide scales. Coefficients of determination (r ²) for relationships between the SMIX values and maize, soybeans, and hay yields at the statewide level are 0.88, 0.74, and 0.81, respectively, when the period of integration is terminated at the end of the growing season. This new soil index can be employed to forecast yields as early as 12 weeks before harvest for the state of Illinois. However, predictions with RMSE ≤ 10% of the mean yield can be achieved only for SMIX integration periods ending 5, 9, and 6 weeks before harvest for maize, soybeans, and hay, respectively. Nomograms are presented for using the relationships between the SMIX values and crop yields to forecast Illinois's major crops well before harvest.