WATER MASS FORMATION IN THE SOUTH INDIAN OCEAN BY AIR-SEA FLUXES

1Introduction　TheIndianCentralWater (ICW) ,formedandsubductedintheSubtropicalConvergenceintheSouthIndianOcean ,occupiesasignificantportionofthethermoclineintheIndianOcean[1,2 ]　 (Fig .1 ) .TheSubantarcticModeWater(SAMW)isformedinthe 2 6.5-2 7.1σθrangenorthoftheSub antarcticFront—thesouthernboundaryofthesubtropicalgyres[3]　 .InthesoutheastIndianO cean ,theSAMWisthethickest,ventilatedasathicklayerofhighoxygenextendingtothetropicalIndianOcean[4 ,5 ]　 .　Watermasstransformation…     

东海陆坡海底块体运动地形分析方法

随着油气资源开发向深水区发展,迫切需要采用一定的方法去了解块体运动的特征以及分析块体运动对深水油气资源开发的可能性.本文阐述了东海陆坡块体运动地形分析方法以及多种数据处理技术的使用.多波束测深系统为人们提供了直观的海底地貌形态特征,地层剖面仪系统能探测海底以下沉积物性质和结构的变化.GIS、Fledermaus、Delph等软件系统可以定量分析海底微地貌形态特征.     

北祁连中西段与超基性岩有关的金矿化特征及成因探讨

北祁连中西段发育三套早古生代蛇绿岩及相应的基性、超基性岩,呈北、中、南三条带状分布。区内金的活化、迁移主要受控于超基性岩带和与其分布近于一致的两条韧性剪切带,金矿化主要发生在强蚀变超基性岩体内、岩体与围岩接触带、断裂破碎蚀变带内。根据包裹体测温及成分测定、稳定同位素特征资料及超基性岩中金丰度值等分析,金矿物质主要来自超基性岩,流体来源于深部,其成因属与超基性岩有关的韧性剪切带型金矿床。     

The chemical changes of DOM from black waters to coastal marine waters by HPLC combined with ultrahigh resolution mass spectrometry

How dissolved organic matter (DOM) undergoes chemical changes during its transit from river to ocean remains a challenge due to its complex structure. In this study, DOM along a river transect from black waters to marine waters is characterized using an offline combination of reversed-phase high performance liquid chromatography (RP-HPLC) coupled to electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS), as well as tandem ESI-FTICR-MS. In addition, a water extract from degraded wood that mainly consists of lignins is used for comparison to the DOM from this transect. The HPLC chromatograms of all DOM samples and the wood extract show two major well-separated components; one is hydrophilic and the other is hydrophobic, based on their elution order from the C₁₈ column. From the FTICR-MS analysis of the HPLC fractions, the hydrophilic components mainly contain low molecular weight compounds (less than 400 Da), while the hydrophobic fractions contain the vast majority of compounds of the bulk C₁₈ extracted DOM. The wood extract and the DOM samples from the transect of black waters to coastal marine waters show strikingly similar HPLC chromatograms, and the FTICR-MS analysis further indicates that a large fraction of molecular formulas from these samples are the same, existing as lignin-like compounds. Tandem mass spectrometry experiments show that several representative molecules from the lignin-like compounds have similar functional group losses and fragmentation patterns, consistent with modified lignin structural entities in the wood extract and these DOM samples. Taken together, these data suggest that lignin-derived compounds may survive the transit from the river to the coastal ocean and can accumulate there because of their refractory nature.     

金川二矿区充填体稳定性的影响因素分析

充填采矿法以其高回收率、低贫化率的优点, 尤其在矿体赋存条件复杂、地表环境需要保护以及容易发生岩爆的矿床开采中具有不可替代的作用。金川二矿区数十年充填开采实践表明, 影响充填体稳定性的主要因素包括矿山工程地质条件、充填体强度、回采工艺以及围岩边界条件等, 其中充填体强度特性往往事关充填采矿工程的成败, 矿体回采进路尺寸是影响充填体承载层稳定性的关键因素, 充填体与围岩体的不规则边界可以转移充填体的部分自重力到围岩体中, 减小作用在承载层上的作用力, 从而达到提高充填体稳定性的目的。     

鄂尔多斯盆地姬塬地区延长组下组合油源特征综合研究

在充分总结姬塬地区延长组下组合大量原油及烃源岩生物标志化合物资料的基础上,结合研究薄弱带的铁边城区块的原油样品族组分组成、饱和烃色质及烃源岩样品总有机碳、热解、族组分组成及饱和烃色质测试结果,系统分析了研究区目的层段的油源特征,并明确了原油与烃源岩在空间上的匹配特征。结果表明,C30重排藿烷含量差异能够有效区分长7、长9烃源岩及生成烃类。长7油页岩为主力烃源岩,长7灰黑色泥岩次之。在姬塬地区东南部的铁边城区块存在长9烃源岩分布,且对长9油层组有一定程度的生烃贡献。空间上,姬塬地区延长组下组合的油源特征具有明显的分区性,大致以古峰庄东—红井子—姬塬西—樊学西南为分界,界限东北部区域的Ⅰ类原油为西南部长7油页岩长距离侧向运聚结果,东南端的Ⅰ-Ⅱ类过渡型原油为长7油页岩与长9暗色泥岩混合贡献产物;界限西南部区域的Ⅱ-Ⅲ类原油来自长7黑色泥岩。     

A numerical study of flexural buckling of foliated rock slopes

The occurrence of foliated rock masses is common in mining environment. Methods employing continuum approximation in describing the deformation of such rock masses possess a clear advantage over methods where each rock layer and each inter‐layer interface (joint) is explicitly modelled. In devising such a continuum model it is imperative that moment (couple) stresses and internal rotations associated with the bending of the rock layers be properly incorporated in the model formulation. Such an approach will lead to a Cosserat‐type theory. In the present model, the behaviour of the intact rock layer is assumed to be linearly elastic and the joints are assumed to be elastic–perfectly plastic. Condition of slip at the interfaces are determined by a Mohr–Coulomb criterion with tension cut off at zero normal stress. The theory is valid for large deformations. The model is incorporated into the finite element program AFENA and validated against an analytical solution of elementary buckling problems of a layered medium under gravity loading. A design chart suitable for assessing the stability of slopes in foliated rock masses against flexural buckling failure has been developed. The design chart is easy to use and provides a quick estimate of critical loading factors for slopes in foliated rock masses. It is shown that the model based on Euler's buckling theory as proposed by Cavers (Rock Mechanics and Rock Engineering 1981; 14 :87–104) substantially overestimates the critical heights for a vertical slope and underestimates the same for sub‐vertical slopes. Copyright © 2001 John Wiley & Sons, Ltd.