X-ray evidence for Ge/Si(001) island columns in multilayer structure

A Ge/Si(0 0 1) multilayer structure is investigated by cross-sectional transmission electron microscopy, atomic force microscopy and double crystal X-lay diffraction. We find that the multilayer-structure-related satellite peaks in the rocking curve exhibit a similar nonuniform broadening and rye fit the zero-order peak with two Lorentz lineshapes. The ratio of the integrated intensity of two peaks is approximately equal with the anal ratio of the top Ge layer deposited between the areas that are and are not occupied by islands. It proves the existence of vertical-aligned island columns from the viewpoint of macroscopic dimension. (C) 2001 Elsevier Science B.V. All rights reserved.

古龙咀周围海区沉积物粒度特征及海底地形变化

对古龙咀周围浅海区沉积物的粒度进行了测试与分析，结合相关的地质水文资料，探讨了海岸形态对沉积物粒度的影响。研究区表层沉积物平均粒径在海湾浅海区呈带状由岸向海变细，中等水深和岬角处分布着细粒区，向外海粒径相对变粗；除险岛湾砂质区外，分选差；偏态多数为正偏或近正态；整体峰形极窄，峰型多样。底质类型以粘土质粉砂和砂质粉砂为主，由东北经古龙咀岬角向西南形成S形粘土质粉砂分布带，险岛湾地区沉积物呈带状由砂逐渐过渡到粉砂。潮汐和波浪是本区沉积物输运的主要水动力，岬角的存在影响了沉积物粒度的分布。粒度趋势分析表明沉积物整体有向岬角汇聚的输运趋势。 对收集到基于1954年、1969年、1982年测量绘成的地形图水深数据进行数字化，结合2005年测量的水深数据，分别建立各时期DEM图，在此基础上分析研究区的地形特征。四个时期海底DEM呈现出大体一致的趋势，在险岛湾及白沙口海湾内为浅水区，水深值在-1～-4 m之间，深水区主要分布在南黄岛南端至古龙咀连线以南区域，呈扇形展布，水深由南黄岛两侧向中间逐渐加深，水深值在-10～ -17 m之间。从整体上看，研究区海底地形呈NW-SE方向逐渐加深。 将数字化后的水深数据统一校正到1956黄海高程系，分别建立DEM，运用GIS的栅格计算分析得出冲淤变化图。相关结果表明：1954～1969年研究区整体近岸为冲（险岛湾除外），离岸海域为淤；1969～1982年研究区总体处于弱淤积状态；1982-2005研究区海域近岸为淤，外海以弱冲刷状态为主。

Isotope Geochemistry of Gold Ore Deposits in the Gezhen Shear Zone, Qiongxi, Hainan Island

Gold deposits hosted in the Gezhen shear zone at Qingxi, Hainan Island occur in the Precambrian metamorphic rock series and are regionally developed in the N-E direction along the tectonic zone. From northeast to southwest are distributed the Tuwaishan-Baoban gold mining district, the Erjia gold mining district and the Bumo gold mining district, making up the most industrially important gold metallogenesis zone on the Hainan Island. Isotope geochemical studies of the typical gold deposits in this metallogen