A study on the exchange additivity of zinc in solid mixtures in seawater——Ⅱ.Stepwise exchange in δ-MnO2/montmorrillonite mixture

In this study the zinc exchange process and the reason for the non-additive exchange of δ-MnO2/montmorrillonite have been investigated. The results suggest that with pH increasing from 2 to 8, the stepwise exchange of zinc occurs on δ-MnO. and montmorrillonite in their mixture.At low pH zinc ions are bound on δ-MnO2, while at high pH, the exchange on montmorrillonite dominates the surface interaction in the mixture. The study demonstrates that the stepwise exchange and the heterogeneity of the binding sites on δ-MnO2 surface are the reason for the non-additive exchange. It is also shown that when δ-MnO2 amounts to 5 %, zinc exchange on sea sediments is controlled by 8-MnO2.     

Deformation Patterns of an Accretionary Wedge in the Transition Zone from Subduction to Collision Offshore Southwestern Taiwan

Swath bathymetry data and seismic reflection profiles have been used to investigate details of the deformation pattern in the area offshore southwestern Taiwan where the Luzon subduction complex encroaches on the passive Chinese continental margin. Distinctive fold-and-thrust structures of the convergent zone and horst-and-graben structures of the passive margin are separated by a deformation front that extends NNW-ward from the eastern edge of the Manila Trench to the foot of the continental slope. This deformation front gradually turns into a NNE–SSW trending direction across the continental slope and the Kaoping Shelf, and connects to the frontal thrusts of the mountain belt on land Taiwan. However, the complex Penghu submarine canyon system blurs the exact location of the deformation front and nature of many morphotectonic features offshore SW Taiwan. We suggest that the deformation front offshore SW Taiwan does not appear as a simple structural line, but is characterized by a series of N–S trending folds and thrusts that terminate sequentially in an en-echelon pattern across the passive Chinese continental slope. A number of NE–SW trending lineaments cut across the fold-and-thrust structures of the frontal accretionary wedge and exhibit prominent dextral displacement indicative of the lateral expulsion of SW Taiwan. One of the prominent lineaments, named the Yung-An lineament, forms the southeastern boundary of the upper part of the Penghu submarine canyon, and has conspicuous influence over the drainage pattern of the canyon     

基于EOF分析对南海西北海域水体光谱特性的研究

This study presents an analysis of the spectral characteristics of remote sensing reflectance(R_(rs)) in northwestern South China Sea based on the in situ optical and water quality data for August 2018.R_(rs)was initially divided into four classes,classes A to D,using the max-classification algorithm,and the spectral properties of whole R_(rs) were characterized using the empirical orthogonal function(EOF) analysis.Subsequently,the dominant factors in each EOF mode were determined.The results indicated that more than 95% of the variances of R_(rs) are partly driven by the back-scattering characteristics of the suspended matter.The initial two EOF modes were well correlated with the total suspended matter and back-scattering coefficient.Furthermore,the first EOF modes of the four classes of R_(rs)(A-D R_(rs)-EOF_1) significantly contributed to the total variances of each R_(rs) class.In addition,the correlation coefficients between the amplitude factors of class A-D R_(rs)-EOF_1 and the variances of the relevant water quality and optical parameters were better than those of the unclassified ones.The spectral shape of class AR_(rs)-EOF_1 was governed by the absorption characteristic of chlorophyll a and colored dissolved organic matter(CDOM).The spectral shape of class B R_(rs)-EOF_1 was governed by the absorption characteristic of CDOM since it exhibited a high correlation with the absorption coefficient of CDOM(a_g(λ)),whereas the spectral shape of class C R_(rs)-EOF_1 was governed by the back-scattering characteristics but not affected by the suspended matter.The spectral shape of class D R_(rs)-EOF_1 exhibited a relatively good correlation with all the water quality parameters,which played a significant role in deciding its spectral shape.     

Constraining the origin and evolution of confined turbidite systems: southern Cretan margin,Eastern Mediterranean Sea (34°30–36°N)

Bathymetric, 9.5-kHz long-range sidescan sonar (OKEAN), seismic reflection and sediment-core data are used in the analysis of two tectonic troughs south of Crete, Eastern Mediterranean Sea. Here, up to 1.2 s two-way travel time (TWTT) of strata have accumulated since the Middle Miocene in association with extension in the South Aegean region. The study area comprises >100-km- long by >25-km-wide basins filled by sediments subdivided into two seismic units: (1) an upper Unit 1 deposited in sub-basins which follow the present-day configuration of the southern Cretan margin; (2) a basal Unit 2, more than 500 ms (TWTT) thick, accumulated in deeper half-graben/grabens distinct from the present-day depocentres. Both units overlap a locally stratified Unit 3 comprising the pre-Neogene core complex of Crete and Gavdos. In this work, the interpreted seismic units are correlated with the onshore stratigraphy, demonstrating that denudation processes occurring on Crete and Gavdos in response to major tectonic events have been responsible for high sedimentation rates along the proximal southern Cretan margin. Consequently, topographically confined sedimentary units have been deposited south of Crete in the last 12 Ma, including turbidites and other mass-flow deposits fed by evolving transverse and axial channel systems. Surface processes controlling facies distribution include the direct inflow of sediment from alluvial-fan systems and incising mountain rivers onto the Cretan slope, where significant sediment instability processes occur at present. In this setting, seismic profiles reveal eight different types of stratigraphic contacts on basin-margin highs, and basinal areas show evidence of halokinesis and/or fluid escape. The acquired data also show that significant changes to the margin’s configuration occurred in association with the post-Alpine tectonic and eustatic episodes affecting the Eastern Mediterranean.     

北黄海沉积物中重金属分布及环境背景值

本文讨论了北黄海１１个柱状岩芯样的颗粒物（＜０．０６３ｍｍ）中重金属的分布，采用统计学方法对Ｃｕ，Ｐｈ，Ｚｎ和Ｃｄ进行态性检验，用柱样稳定段（拐点以下）作为背景段，获得重金属环境背景值．     

真鲷的营养需要及配合饲料的研究初报

本文综述了真鲷的营养需要，研究了不同植物蛋白源对真鲷生长的影响，并在此基础上设计了三种饲料配方，试验结果表明Ｉ号饲料配方的增长率最高。     

The elemination of re-reflected waves by a porous medium of finite thickness

The elimination of re-reflected waves in a wave channel by installing a porous medium in front of the wavemaker is investigated. The thickness of the porous wall required to eliminate the re-reflected waves is shown to be related to th porosity, friction coefficient, and wave period, as well as to both the positions of the porous medium and the test structure. However, this study indicates that the goal of eliminating re-reflected waves can be achieved by simply varying the thickness of the porous medium according to the wave period, with all the other factors arbitrarily selected.Assuming that the oscillation amplitude of the wavemaker board is constant, the primitive wave amplitude, before reaching the porous medium, becomes smaller as the wave period is increased. In addition, the study found that the required thickness of the porous medium for eliminating the re-reflected wave becomes larger as the wave period is increased. This results in a trend which further reduces the wave amplitude after the wave passes through the porous medium. In consequence, the oscillation amplitude of a wavemaker board has to be adjusted in a larger scale if the wave period is to be increased.     

用铀系定年法测定南永1井珊瑚礁年龄

运用铀系定年法首次对南水1井珊瑚礁岩心中的两个层位进行测年,结果与~(14)C测年一致,证实在晚更新世与全新世之间存在沉积间断面。     

海水中砷标准物质的研制

本文介绍了海水中砷标准物质的研制过程，其中包括溶液的配制、均匀性和稳定性检验，标样的分析方法。并对标准物质的定值数据进行统计处理，两种浓度的定值结果分别为：１．００μｇ／ｃｍ３±０．０４μｇ／ｃｍ３和５１．０μｇ／ｄｍ３±２．６μｇ／ｄｍ３。两种浓度砷标准物质的稳定期均为一年     

法国“阿塔郎特”号海洋调查船上的重力取样

在海洋地质调查中，如何取得好的沉积物样品是每一位海洋地质学家所向往的，而获得好的沉积物样品的关键又很大程度上取决于先进的海洋调查仪器的使用。法国“阿塔郎特”号海洋调查船上的重力取样管不管在性能上，还是安全性上都瞰称世界上比较先进的取样设备。