云南祥云马厂箐富碱斑岩体的地球化学特征及其形成的构造环境

云南祥云马厂箐岩体处于扬子板块西缘与NW向的金沙江—哀牢山深大断裂带东侧交汇部位,属于哀牢山—金沙江富碱侵入岩带的组成部分。马厂箐岩体主要为花岗斑岩、二长斑岩和正长斑岩,岩体化学成分具有富碱、富铝和高钾的特点。岩石富集大离子亲石元素(Rb、Sr、Ba、Th和U)和轻稀土元素(LREE)、相对亏损高场强元素(Ta、Nb和Ti),且Ta、Nb和Ti具"TNT"负异常;LREE/HREE值为8.04～23.99,δEu值为0.72～0.88,负Eu异常不明显;n(87Sr)/n(86Sr)值范围为0.7072～0.7086,均值为0.7080,高于原始地幔现代值0.7045;n(143Nd)/n(144Nd)值范围为0.5121～0.5124,均值0.5123,低于原始地幔现代值0.512638;ISr值范围为0.7061～0.7075,均值为0.7070;εNd值范围为(3.1～(10.2,均值为(6.8。马厂箐岩体既不属于传统的含碱性暗色矿物的碱性岩类,也不同于典型的A型花岗岩,应属于富碱侵入岩类;岩体的岩浆起源于壳—幔物质混合的一种所谓EMⅡ型富集地幔源;其壳幔混合特征,主要是俯冲进入上地幔的地壳物质与地幔物质发生了源区混合作用的结果;形成于碰撞后的板内构造环境。     

郯庐断裂带南段构造演化与邻区成矿作用——从年代学资料得到的启示

郯庐断裂带为我国东部北北东—北东向岩石圈深大断裂带。在其南段的邻区,分布有胶东金矿区、鲁西铁金矿区以及长江中下游的铁铜(金)成矿带和苏北油气田等矿产。从已获得大量测年资料分析,可将构造—岩浆—成矿事件分为3个阶段:1)早期(800～550 Ma):自元古宙泛古陆裂解和随之而来的加里东期古地震和局部海西期喷流作用,证实地壳运动早已拉开了它的"构造活动序幕",此阶段继承和构建了华北克拉通岩石圈先存的构造薄弱带,从成矿作用而论,此阶段可称为"成矿预备场地";2)主期(1 80～110 Ma):在三叠纪期间,扬子板块和华北板块陆—陆碰撞和中生代西太平洋板块向欧亚板块俯冲等,造就了现今郯庐断裂与分支断裂的构造格架。其中主峰形成时间为140～120 Ma±,在这个阶段广泛有钙碱性系列、富钾高锶钙碱系列、碱性系列岩浆和后期成矿热液,沿着有利构造空间剧烈活动和成矿就位。本区壳幔混熔型和壳源同熔型花岗岩,是地壳减薄和下地壳拆沉、底侵的产物,而不是单一的构造运动的结果。此阶段可称为断裂构造—岩浆活动—成矿作用的鼎盛期;3)晚期(60Ma～现代):沿东西向与北北东向(或北东向)断裂交汇处,存在橄榄玄武岩喷侵,为石油和天然气的形成提供了热源和物源,此期可称其为构造—岩浆活动的衰变期。     

Hydrothermal Alteration Related to Silver Mineralization at the Iwami Silver Deposit,Shimane Prefecture,Japan

The Iwami epithermal silver deposit consists of Ag-Cu veins in a dacitic intrusive body at the deep portion of the Eikyu area, and veinlets with disseminated Ag mineralization in dacitic tuff breccia at a shallow portion of the Fukuishi area. Hydrothermal alteration associated with the silver mineralization is characterized by intense potassium metasomatism with oxidizing conditions. An illite zone occurs around the pathways of uprising fluids in both the Eikyu and Fukuishi areas. It grades laterally into the illite/smectite zone, which is surrounded by a broad smectite zone. Because of boiling, abundant adularia associated with silver mineralization overlaps on the altered tuff breccia in the Fukuishi area. The alteration zoning suggests that the western Eikyu area and the eastern Fukuishi area belong to a single hydrothermal system. The data of fluid inclusion microthermometry indicate that the temperatures range 220–270°C, and salinities range 5–7 wt percent NaCl equivalent for the silver mineralization at the upper portion in the Eikyu area and the lower portion in the Fukuishi area. Radiometric ages for volcanic rocks in the area range from 2.19 to 1.64 Ma, and the dacitic intrusion formed at approximately 1.6 Ma. The silver-dominant mineralizing hydrothermal fluids system was active around 1.44 to 1.07 Ma, which formed the Eikyu Ag-Cu veins at depth, and the Fukuishi Ag ores at the shallower portion.     

Re-Os geochronology of Cu and W-Mo deposits in the Balkhash metallogenic belt,Kazakhstan and its geological significance

<正>The Central Asian metallogenic domain(CAMD) is a multi-core metallogenic system controlled by boundary strike-slip fault systems.The Balkhash metallogenic belt in Kazakhstan,in which occur many large and super-large porphyritic Cu—Mo deposits and some quartz vein- and greisen-type W—Mo deposits,is a well-known porphyritic Cu—Mo metallogenic belt in the CAMD.In this paper 11 molybdenite samples from the western segment of the Balkhash metallogenic belt are selected for Re—Os compositional analyses and Re—Os isotopic dating.Molybdenites from the Borly porphyry Cu deposit and the three quartz vein-greisen W—Mo deposits—East Kounrad.Akshatau and Zhanet—all have relatively high Re contents(2712—2772μg/g for Borly and 2.267—31.50μg/g for the other three W—Mo deposits),and lower common Os contents(0.670—2.696 ng/g for Borly and 0.0051—0.056 ng/g for the other three).The molybdenites from the Borly porphyry Cu—Mo deposit and the East Kounrad,Zhanet,and Akshatau quartz vein- and greisen-type W—Mo deposits give average model Re—Os ages of 315.9 Ma,298.0 Ma,295.0 Ma,and 289.3 Ma respectively.Meanwhile,molybdenites from the East Kounrad,Zhanet,and Akshatau W—Mo deposits give a Re—Os isochron age of 297.9 Ma,with an MSWD value of 0.97.Re-Os dating of the molybdenites indicates that Cu—W—Mo metallogenesis in the western Balkhash metallogenic belt occurred during Late Carboniferous to Early Permian(315.9—289.3 Ma),while the porphyry Cu—Mo deposits formed at—316 Ma,and the quartz vein-greisen W—Mo deposits formed at ~298 Ma.The Re—Os model and isochron ages thus suggest that Late Carboniferous porphyry granitoid and pegmatite magmatism took place during the late Hercynian movement.Compared to the Junggar-East Tianshan porphyry Cu metallogenic belt in northwestern China,the formation of the Cu—Mo metallogenesis in the Balkhash metallogenic belt occurred between that of the Tuwu-Yandong in East Tianshan and the Baogutu porphyry Cu deposits in West Junggar. Collectively,the large-scale Late Carboniferous porphyry Cu—Mo metallogenesis in the Central Asian metallogenic domain is related to Hercynian tectono-magmatic activities.     

Biosorption of cadmium(II) from aqueous solution onto <Emphasis Type="Italic">Hydrilla verticillata</Emphasis>

Biosorption is an effective method to remove heavy metals from wastewater. In this work, the biosorption of Cd(II) onto Hydrilla verticillata was examined in aqueous solution with parameters of initial pH, adsorbent dosage, contact time, initial Cd(II) concentration, temperature, and co-existing ion. Linear Langmuir and Freundlich models were applied to describe the equilibrium isotherms, and both of the two models were fitted well. The monolayer adsorption capacity of Cd(II) was found to be 50 mg/g at pH 6 and 20°C. Dubinin–Radushkevich isotherm model was also applied to the equilibrium data. The mean free energy of adsorption (11.18 kJ/mol) indicated that the adsorption of Cd(II) onto H. verticillata might be carried out via chemical ion-exchange mechanism. Thermodynamic parameters, including free energy (∆G ⁰), enthalpy (∆H ⁰), and entropy (∆S ⁰) of adsorption, were also calculated. These results showed that the biosorption of Cd(II) onto H. verticillata was a feasible, spontaneous, and exothermic process in nature. Desorption experiments indicated that 0.01 mol/L EDTA and HNO₃ were efficient desorbents for the recovery of Cd(II) from biomass. IR spectrum analysis suggested that amido, hydroxyl, C=O and C–O could combine strongly with Cd(II). EDX spectrum analysis suggested that an ion exchange mechanism might be involved.     

龙口湾水动力特征及其对人工岛群建设的响应

基于龙口湾及附近海域的水文实测资料,利用Mike21数学模型模拟了人工岛建设前后的潮流、波浪、纳潮量及水交换率等水动力特征,探讨了人工岛群建设对龙口湾水动力环境的影响。结果表明,人工岛建设显著改变了龙口湾潮流场特征及水体运动路径,湾内受到人工岛的阻挡,流速普遍减小,局部区域潮流运动形式由往复流变为旋转流,流向变化较大,余流形成多个涡旋;湾外由于堤头挑流作用导致局部区域流速增大且余流流速增大,潮流运动形式未发生明显改变。受人工岛的掩蔽作用,人工岛及附近区域的波浪有效波高普遍减小。龙口湾潮位出现北部最大潮差变小、南部最大潮差增大的格局,壅水作用导致人工岛内部水道潮差变化明显。人工岛建设直接占据了龙口湾海域面积,导致其纳潮量明显减小,水交换率呈现南部和北部增大、人工岛北侧以及内部水道减小的特征,人工岛造成的水动力环境的改变是影响水交换率变化的主要原因。人工岛群建设导致龙口湾内的潮流、波浪、纳潮量以及水交换等水动力特征减弱,是引起龙口湾水动力条件变化的根本因素。     

Experimental Study of Overtopping on Sea Dikes and Coastal Flooding Under the Coupled Processes of Tides and Waves

Storm surges are cataclysmic natural disasters that occur along the coasts and are usually accompanied by large waves. The effects of coupled storm surges and waves can pose a significant threat to coastal security. Previous laboratory studies on the effects of storm surges and waves on coastal structures have typically utilized steady water levels and constant wave elements. An indoor simulation of the coupled processes of tides and waves is developed by adding a tide generation system to an existing laboratory wave basin to model continuous dynamic tide levels so that tide generation and wave-making occur synchronously in the pool. Specific experimental methods are given, which are applied to further study waves overtopping on artificial sea dikes and coastal flooding evolution under the coupled actions of tides and waves. The results of the overtopping discharge obtained by the test with a dynamic water level are compared with those obtained from steady water level tests and the existing empirical formula. In addition, the impacts of ecological coastal shelterbelts and structures on coastal flood processes and distributions are also investigated. The proposed simulation methods provide a new approach for studying the effects of storm surges and waves on coastal areas. The study also aims to provide a reference for coastal protective engineering.

     

一类信号恢复问题的投影迭代硬阈值算法

本文给出了基于L₀模求解该问题的非凸模型,借助于稀疏正则化方法来克服问题的不适定性。该模型利用紧小波框架对信号进行稀疏逼近,并利用L₀模度量稀疏性。提出了求解该模型的投影迭代硬阈值算法,并证明了算法的全局收敛性。该算法每一步都有闭式解,计算过程简洁高效。数值实验表明,方法在重建信号的视觉质量和量化指标方面均优于所对比的pFISTA方法。     

老工业区产业结构转型与用地结构转型互动机制及优化路径——以上海市宝山区为例

尝试理清老工业区产业结构转型与用地结构转型内涵,提出其转型效率的函数表达,分析二者间的互动关系;并运用改进的动态变化度及偏离系数,对上海市宝山区进行实证研究。结果表明:(1)宝山区产业结构与用地结构变化度逐渐增加,工业和第三产业动态度分别由1996年的2.48%和5.36%上升至2012年的4.75%和5.51%,用地结构动态度由11.16%上升至13.53%;(2)宝山区三次产业结构总体趋于优化,但产业内部并未优化,仍以重化工业和传统服务业为主导;(3)宝山区用地结构与产业结构不协调并处于加剧的状态。老工业区产业结构与用地结构存在较强的互动关系,改进的动态变化度及偏离系数方法为老工业区产业结构转型与用地结构转型问题提供了一种研究思路。提出宝山区产业结构转型与用地结构转型的优化路径。     

南半球环状模与南极冰芯中气候信息关联研究综述

冰芯作为气候环境信息的良好载体,在研究过去大气环流异常中具有其他气候代用指标难以比拟的优势。本文重点综述了南极冰芯气候记录与南半球环状模(SAM-Southern Annular Mode)的关联特征:SAM与冰芯记录为同期变化,冰芯中NO-3、海盐组分(以Na+为代表)和水同位素比值δ18O同SAM指数具有较好的关联性;冰芯中SO2-4和MSA同SAM存在一定的关联,但相关性不显著;西南极冰芯记录的积累率同SAM具有较强的关联。需要说明的是,冰芯中各参数与SAM的相关性存在较大的空间差异。