Summertime Surface N2O Concentration Observed on FildesPeninsula Antarctica： Correlation with TotalAtmospheric O3 and Solar Activity     

ZHU Renbin  SUN Liguang  YIN Xuebin  LIU Xiaodong  XING Guangxi 《大气科学进展》2004,21(2):204-210

Three-year summertime surface atmospheric N2O concentrations were observed for the first timeon the Fildes Peninsula, maritime Antarctica, and the relationships among the N2O concentration, totalatmospheric O3 amount, and sunspot number were analyzed. Solar activity had an important effecton surface N20 concentration and total O3 amount, and increases of sunspot number were followed bydecreases in the N2O concentration and total O3 amount. A corresponding relationship exists betweenthe N2O concentration and total atmospheric O3, and ozone destruction was preceded by N2O reduction.We propose that the extended solar activity in the Antarctic summer reduces the stratospheric N2O byconverting it into NOx, increases the diffusion of N2O from the troposphere to the stratosphere, decreasesthe surface atmospheric N2O, and depletes O3 via the chemical reaction between O3 and NOx. Ourobservation results are consistent with the theory of solar activity regarding the formation of the AntarcticO3 hole.  相似文献   

个旧塘子凹锡多金属矿床微量元素地球化学特征   总被引：4，自引：0，他引：4  

贾润幸  方维萱  赫英  高振敏  李红阳 《矿物学报》2004,24(2):136-142

塘子凹矿床位于个旧老厂矿田的西北部，矿体按产出方式可分为接触带原生硫化矿和脉状氧化矿。本文着重从微量元素地球化学和矿物地球化学角度探讨了本区脉状氧化矿的成因问题，认为该区脉状氧化矿与接触带原生硫化矿具有同源性，而与围岩大理岩没有成因联系；在成矿后期，地表流体对脉状矿体中多种微量元素特别是V、As、Sb、Bi等有强烈的富集作用。  相似文献   

Ground-Based UV Measurements of BrO and OClO over Ny-Ålesund during Winter 1996 and 1997 and Andøya during Winter 1998/99     

K. K. Tørnkvist  D. W. Arlander  B.-M. Sinnhuber 《Journal of Atmospheric Chemistry》2002,43(2):75-106

Presented here are measurements of BrO and OClO performed by ground-based UV-visible zenith-sky viewing spectrometers developed by the Norwegian Institute for Air Research (NILU). Measurements were taken at Ny-Ålesund, Spitsbergen (79° N, 11° E), in winter and spring1996 and 1997 and at Andøya (69.3° N, 16° E) from summer 1998 until summer 1999. AM and PM differential slant column densities (DSCDs) at 90°SZA of BrO and OClO reached their maxima during polar vortex conditions in the winter months and were anti-correlated to temperature andNO₂. Comparison of BrO with a 3-D chemical transport model showed good agreement for seasonal trends and non-vortex conditions. BrO AM/PM ratios were underestimated by the model for vortex conditions, indicating the need for better quantification of BrO source and sink reaction rates. The detection of OClO above 200 K at the 475 K isentropic level indicates the possible activation of chlorine on sulphate particles. Several episodes of boundary layer ozone depletion due to marine-derived BrO were evident in our zenith-skyspectra during April 1997 in Ny-Ålesund.  相似文献   

卤水-白云石法氧化镁产品中降低锰含量工艺条件的探索     

马建国  方裕勋  王年罗 《华东地质学院学报》2002,25(1):55-58

研究了卤水－白云石法氧化镁产品中降低锰含量的工艺条件，通过白云石加硝酸钾煅烧或氢氧化镁沉淀中加PAN络合、氯仿萃取的方法降低氧化镁中锰含量。该工艺操作较简便、氧化镁中含量降至0．007％以下，氧化镁纯度达98％以上，取得满意结果。  相似文献   

尼日利亚石类矿物的晶体化学研究及其意义     

陈敬中  王秋玲  韩炜  彭珏  张荣红 《矿物学报》2002,22(1):43-48

湖南省安化、临武、柿竹园等地区有一类含锡、镁、铁、锌、钛、锰、铝等多种元素的复杂氧化物矿物 ,它们是尼日利亚石、镁尼日利亚石 (彭志忠石 )等。本文从紧密堆积原理出发 ,深入探讨了尼日利亚石类矿物的晶体化学特征。它们的晶体结构可用O(阳离子八面体配位的层 )、T1(阳离子八面体配位与一种方向阳离子四面体配位的混合层 )、T2 (阳离子八面体配位与两种方向阳离子四面体配位的混合层 )堆积方式表征 ,O层与T层交替排列。尼日利亚石 6H的晶体结构表示为…OT2 OT1OT1… ,尼日利亚石 2 4R的晶体结构表示为…OT1OT2 OT2 OT1…× 3 ,等等 ;它们的晶体结构中既有尖晶石的…OT2 OT2 … ,又有铁钒矿的…OT1OT1…晶体结构单位。这类矿物研究在矿物学、宝石学、材料科学等方面有重要的理论和实际意义  相似文献   

Nitrous oxide in fresh water systems: An estimate for the yield of atmospheric N2O associated with disposal of human waste     

W. A. Kaplan  J. W. Elkins  C. E. Kolb  M. B. McElroy  S. C. Wofsy  A. P. Durán 《Pure and Applied Geophysics》1978,116(2-3):423-438

The N₂O content of waters in the Potomac and Merrimack Rivers was measured on a number of occasions over the period April to July 1977. The concentrations of dissolved N₂O exceed those which would apply in equilibrium with air by factors ranging from about 46 in the Potomac to 1.2 in the Merrimack. Highest concentrations of dissolved N₂O were associated with sewage discharges from the vicinity of Washington, D.C. and analysis indicates a relatively high yield, 1.3 to 11 percent, for prompt conversion of waste nitrogen to N₂O. The yield could be even higher if bubbles originating in sediments should contain as little as 0.3 percent N₂O. Measurements of dissolved N₂O in fresh water ponds near Boston demonstrate that aquatic systems may provide both strong sources and sinks for atmospheric N₂O.  相似文献   

水晶晶体中的球粒状与管状铁氧化物包裹体的形貌结构与成因     

张良钜  饶灿  张昌龙  阮青锋  雷威  廖宝丽  何涛 《地质论评》2008,54(6):786-792

产出在四川美姑峨眉山玄武岩中的水晶有两种类型,即产出在玄武岩气孔中第一成矿阶段紫色水晶和“三色”层水晶与玄武岩层间滑（错）动裂隙或晶洞中第二成矿阶段的浅色水晶。晶体中铁氧化物包裹体为镜铁矿、赤铁矿、纤铁矿。包裹体的形貌结构有两种类型：其一具三圈层构造球粒（0.15~0.5㎜）,它由球核、球壳与表层三部分组成,球核与表层为红棕色,球壳为铁黑色,称“红夹黑”。扫描电镜（SEM）与能谱分析（EDS）表明,球壳由绕球核呈放射状排列的片状镜铁矿组成,表层为红色半透明鳞片状纤铁矿,球核由微晶赤铁矿定向聚合呈圆球形或向外伸出的圆柱形,球粒产出在“三色”层水晶的红棕色间歇层的夹层（0.4~0.7㎜）中;其二具两圈层构造的中空管,管的长轴方向垂直水晶的菱面体单形晶面方向。SEM及EDS测试表明,管中心为空管,内圈为铁黑色片状镜铁矿,外圈为厚度不一的红棕色赤铁矿,管的形貌有滴管状、钟乳状、倒葫芦状,晶出在第二成矿阶段第一世代条带状水晶的条带中。“三色”层及条带状水晶中的包裹体是强酸性氧逸度高、且热动力生长环境条件极不稳定的产物。水晶流体包裹体均一温度及拉曼光谱分析研究,水晶矿属低温热液（150~190℃）成矿,成矿流体的盐度较低, 5.7%~13.2%NaCl_eq,其中紫晶盐度最高（13.2% NaCl_eq）,条带状水晶盐度较低（6% NaCl_eq）。流体包裹体主要由H₂O和SO₂及微量CH₄组成。这项研究对了解铁氧化物生长机理、生长速率、生长环境热动力条件变化及成矿阶段划分都具重要意义,同时对研究现今表生氧化环境所形成铁氧化物种类、机理也有现实指导意义。  相似文献   

Mixed messages in iron oxide–copper–gold systems of the Cloncurry district,Australia: insights from PIXE analysis of halogens and copper in fluid inclusions     

Timothy Baker  Roger Mustard  Bin Fu  Patrick J. Williams  Guoyi Dong  Louise Fisher  Geordie Mark  Chris G. Ryan 《Mineralium Deposita》2008,43(6):599-608

Proterozoic rocks of the Cloncurry district in NW Queensland, Australia, are host to giant (tens to hundreds of square kilometers) hydrothermal systems that include (1) barren regional sodic–calcic alteration, (2) granite-hosted hydrothermal complexes with magmatic–hydrothermal transition features, and (3) iron oxide–copper–gold (IOCG) deposits. Fluid inclusion microthermometry and proton-induced X-ray emission (PIXE) show that IOCG deposits and the granite-hosted hydrothermal complexes contain abundant high temperature, ultrasaline, complex multisolid (type 1) inclusions that are less common in the regional sodic–calcic alteration. The latter is characterized by lower salinity three-phase halite-bearing (type 2) and two-phase (type 3) aqueous inclusions. Copper contents of the type 1 inclusions (>300 ppm) is higher than in type 2 and 3 inclusions (<300 ppm), and the highest copper concentrations (>1,000 ppm) are found both in the granite-hosted systems and in inclusions with Br/Cl ratios that are consistent with a magmatic source. The Br/Cl ratios of the inclusions with lower Cu contents are consistent with an evaporite-related origin. Wide ranges in salinity and homogenization temperatures for fluid inclusions in IOCG deposits and evidence for multiple fluid sources, as suggested by halogen ratios, indicate fluid mixing as an important process in IOCG genesis. The data support both leaching of Cu by voluminous nonmagmatic fluids from crustal rocks, as well as the direct exsolution of Cu-rich fluids from magmas. However, larger IOCG deposits may form from magmatic-derived fluids based on their higher Cu content.  相似文献   

盐湖卤水制备工业级氢氧化镁和氧化镁中氯的存在形式研究          下载免费PDF全文

宋磊  曹雨微  王景凤  刘远  孔会民  宋学文 《盐湖研究》2021,29(3):90-97

氯离子作为利用盐湖镁资源制备高端镁产品的主要杂质,严重影响了产品的应用价值。为探索出氯离子的存在形式,有效降低氯含量,文章通过SEM、EDS等物理表征方法,结合化学分析检测手段,设计了三种研究方案,探明了盐湖卤水制备工业级Mg(OH)_2和MgO中杂质氯的存在形式有结合态和游离态两种。结合Mg(OH)_2和MgO的生产工艺,还系统分析了产品中氯的形成机理,对生产过程中控制和降低氯杂质提供了合理化建议。  相似文献   

MgO‐Based Binder for Treating Contaminated Sediments: Characteristics of Metal Stabilization and Mineral Carbonation          下载免费PDF全文

Kyung‐Yup Hwang  Jeong‐Yun Seo  Hoang Q. H. Phan  Jun‐Young Ahn  Inseong Hwang 《洁净——土壤、空气、水》2014,42(3):355-363

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