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1.
橄榄岩蛇纹石化过程中氢气和烷烃的形成 总被引：1，自引：1，他引：0
蛇纹石化过程中形成氢气、烷烃和有机酸,为海底热液区生命活动提供物质和能量来源,可能对地球和其他行星早期生命起源和演化有重要影响。目前关于蛇纹石化过程中氢气和烷烃形成的研究大多以橄榄石为初始物,且温度和压力较低(≤300℃,500bar)。本研究通过一系列的水热实验,研究300~500℃、1~3kbar时橄榄石、斜方辉石、单斜辉石、橄榄岩、玄武岩以及玄武岩与橄榄岩混合物发生蛇纹石化反应后氢气和烷烃的生成。300℃、3kbar时,橄榄石蛇纹石化后产生的氢气远大于辉石蚀变后产生氢气的量。随着温度的增加,400~500℃、3kbar时,橄榄石蚀变程度极低,产生氢气的量低于斜方辉石。单斜辉石实验后没有发生蚀变,不产生氢气和烷烃。400~500℃、3kbar时,橄榄岩蛇纹石化后产生的氢气和烷烃远高于橄榄石、斜方辉石和单斜辉石。玄武岩蛇纹石化后生成氢气和甲烷的量低于橄榄岩,但与玄武岩和橄榄岩混合物相当。这是因为玄武岩的单斜辉石蚀变后形成富铁的透辉石(~8.1%FeO),透辉石的Fe以Fe2+为主,这降低了Fe3+和氢气的量。以上表明,橄榄岩的蛇纹石化不同于橄榄石和斜方辉石。不仅是海底热液蚀变产生氢气和甲烷,洋壳俯冲过程中地幔楔橄榄岩蛇纹石化也会生成氢气和甲烷,但由于洋壳玄武岩的加入,氢气和甲烷的量会远小于橄榄岩蚀变时的量。 相似文献
2.
本文利用电子背散射衍射(EBSD)技术对河北张家口大麻坪汉诺坝玄武岩橄榄岩捕虏体中斜方辉石与玄武岩反应结构的显微构造进行了详细研究。研究结果表明: ① 其反应边具有复杂的多层筛状结构特征,包括玄武岩层、富橄榄石层以及橄榄石和单斜辉石交生层;② 由外至内,橄榄石的Mg值逐渐升高,而单斜辉石的Mg值变化不大;③ 反应边结构中的单斜辉石与斜方辉石残斑之间存在很好的结晶学拓扑关系,即(100)opx//(100)cpx、(010)opx//(010)cpx、(001)opx//(001)cpx;④ 橄榄石的结晶学取向无序且与斜方辉石和单斜辉石均无关。这个反应过程可以用贫硅熔体先与斜方辉石反应形成单斜辉石,并导致熔体富硅,从而橄榄石从反应熔体中结晶出来合理地解释。相对富硅熔体与橄榄岩的反应,贫硅熔体与橄榄岩的反应过程由于筛状反应边的存在可能更容易进行,筛状结构反应边可以为熔体在橄榄岩中沿颗粒边界运移提供通道,并使橄榄岩主要组成矿物发生细粒化和岩石结构变得松散,可以有效保证熔体上升过程中对橄榄岩的持续侵蚀和破坏,从而可能导致岩石圈地幔性质的迅速转变。 相似文献
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酸解烃是油气化探方法中准确度相对较高的一项指标,已得到广泛的应用,深入研究酸解气有助于对其机理的进一步解释,并且有利于开发新的分析指标。本文利用气相色谱法测定了油气化探样品经盐酸分解后所得气体中烃类组分与非烃气体组分的含量,发现了酸解气中甲烷与氢气的含量具有正相关性。进而通过X射线荧光光谱和X射线衍射分析样品的元素和矿物组成、样品再粉碎分析以及激光拉曼光谱分析包裹体成分等实验,获得以下结论:(1)酸解气中的甲烷和氢气含量与样品元素组成无关,与碳酸盐矿物正相关,其含量可以反映深部油气的情况;(2)两种气体并不是以物理吸附形式存在于样品中,而是存在于更小的空间内,证明了酸解烃分析方法具有相当高的稳定性;(3)获得了甲烷和氢气同时存在于包裹体的直接证据,由此推测这两种气体可能具有同源性。由于甲烷和氢气含量相关性的存在,酸解脱气中氢气的含量测定有望成为油气化探的新指标,应用于油气资源调查。 相似文献
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橄榄岩-熔体的相互作用:岩石圈地幔组成转变的重要方式 总被引：31，自引：2，他引：31
橄榄岩-熔体/岩浆的相互作用常被用来解释蛇绿岩套橄榄岩、造山带橄榄岩、超镁铁质侵入杂岩体、地幔橄榄岩捕虏体中某些具有不平衡结构和矿物组成的岩石的形成过程。橄榄岩-熔体的反应主要有两种方式,即消耗橄榄石(和单斜辉石)生成斜方辉石或消耗斜方辉石生成橄榄石(和单斜辉石)。反应的结果不仅造成矿物百分含量的变化,而且造成矿物组成的变化;后者更重要但未引起足够的重视。华北东部中生代玄武质岩石中具有环带状结构的橄榄石和辉石捕虏晶,特别是具有环带状结构的地幔橄榄岩捕虏体的发现,暗示这种橄榄岩-熔体的相互作用在华北东南部中生代岩石圈地幔中很可能普遍存在,为岩石圈地幔组成转变和快速富集的重要方式。这是全球首例由橄榄岩-熔体相互反应造成的岩石圈地幔大规模的组成变化。反应熔体来源途径主要有地壳来源和软流圈地幔来源。来源不同的熔体与橄榄岩的反应造成的组成变化完全不同。 相似文献
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昌乐方山新生代玄武岩中携带有大量深源捕虏岩,其岩石类型以二辉辉石岩、二辉橄榄岩为主,方辉橄榄岩、单斜辉石岩、单辉橄榄岩少见,未见纯橄岩。二辉辉石岩、二辉橄榄岩、方辉橄榄岩的矿物岩石、地球化学特征和平衡温度压力计算显示为地幔来源,采用地质温度压力计进行计算,获取三者都源于岩石圈地幔,形成的深度范围为41~66.7 km。根据单辉橄榄岩和单斜辉石岩的矿物化学分析,单斜辉石岩和单辉橄榄岩形成深度要低于前三者,且与前三者有密切成因联系。"熔体—岩石"反应在各类深源捕虏岩中广泛存在,除方辉橄榄岩样品不存在明显的"熔体—岩石"反应外,二辉辉石岩、单斜辉石岩、二辉橄榄岩中不同的矿物边缘与玄武质熔体接触部位有着不同类型的反应边和反应矿物出现:橄榄石边部发生(Mg,Fe)_2SiO_4(镁橄榄石)+熔体(原始岩浆)=(Mg,Fe)_2SiO_4(贵橄榄石)+熔体(演化岩浆)反应,使得边部富铁贫镁;单斜辉石与玄武质熔体反应,多具有粉红色反应边,具有富Ti、Al、Fe,贫Si、Mg,较玄武岩基质中单斜辉石斑晶更低Mg~#的特征。斜方辉石与玄武质熔体反应生成复杂的反应带,存在斜方辉石+熔体=橄榄石+SiO_2(熔体)+单斜辉石的反应,反应带内新生成的矿物由内向外具有明显趋向玄武质熔体成分的变化;尖晶石与玄武质熔体反应边缘具有富Fe、Ti,贫Mg、Al,以及更高的Cr~#,趋向于形成钛铁矿的变化特征。二辉橄榄岩中熔体囊和单辉橄榄岩中筛状单斜辉石以及粉红色的反应边都暗示了二者至少经历了两个期次的熔体作用。随着岩石圈地幔的演化,熔体的再富集作用使得难熔的方辉橄榄岩逐渐转变为相对富集的二辉橄榄岩,后期二辉橄榄岩又与玄武质熔体反应,生成更加富集的单辉橄榄岩,而方山方辉橄榄岩也受到了熔体的轻度改造,已不具有难熔古老岩石圈地幔岩石的显著特征,鲁西新生代玄武岩中深源捕虏体与熔体的反应广泛存在,熔体成分以玄武质为主,这可能是华北克拉通岩石圈置换的重要方式之一,导致古老岩石圈地幔的消失。 相似文献
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温度对低煤阶煤生物甲烷生成的影响 总被引：1，自引：0，他引：1
温度是煤层生物甲烷生成的重要控制因素之一。为研究不同温度条件下生物甲烷的生成量及其变化规律,在实验室条件下,对河南义马低煤阶煤在不同温度(25℃、35℃、45℃、55℃、65)℃下进行了生物甲烷模拟生成实验,并通过对不同反应阶段生成气体的组分及体积分数的检测,探讨了温度对低煤阶煤之甲烷生成的影响。实验结果表明:35℃时,生物甲烷含量最大,而在45℃和55℃时,甲烷含量有所下降;随着反应的持续进行,生成气体中甲烷体积分数逐渐增高(由11.4%增至65.71%),而二氧化碳的体积分数则呈下降趋势(由30.59%降至15.37%)。 相似文献
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北秦岭松树沟橄榄岩与铬铁矿矿床的成因关系 总被引：2，自引：1，他引：1
松树沟橄榄岩体是秦岭造山带中规模最大的赋存铬铁矿床的超基性岩体。松树沟橄榄岩主要由细粒橄榄岩质糜棱岩和中粗粒橄榄岩组成。本文通过对松树沟橄榄岩的岩相学、主微量、稀土元素地球化学的系统研究,认为松树沟细粒方辉橄榄岩为洋脊扩张过程中地幔岩减压-近分离熔融产生的残留体,细粒纯橄岩主要由地幔橄榄岩熔融残留橄榄石、消耗辉石的减压熔融反应:aCpx+bOpx+cSpl=dOl+1Melt生成的橄榄石和少量的地幔方辉橄榄岩残留体组成,但均受到了后期渗滤熔体的再富集作用;中粗粒纯橄岩和方辉橄榄岩主要为上述反应产生的渗滤熔体被圈闭在迁移通道或减压扩容带内在热边界层(TBL)通过反应:MeltA=Ol+MeltB冷凝结晶而成,属堆晶橄榄岩。Pb-Sr-Nd同位素地球化学的证据显示,松树沟橄榄岩与基性岩具有共同的地幔源区,二者同为松树沟蛇绿岩的重要组成部分。通过矿床地质特征及铬铁矿电子探针测试研究,认为松树沟铬铁矿床是产于中粗粒堆晶纯橄岩中的层状铬铁矿床,形成于格林威尔期松树沟洋盆的扩张过程中,是中粗粒纯橄岩在热边界层(TBL)的冷凝结晶过程中岩浆分异作用的产物。 相似文献
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海洋天然气水合物氢氧同位素分馏初探 总被引：1，自引：0，他引：1
天然气水合物的形成会造成氢、氧同位素的分馏.在实验室合成研究中,利用天然海水 [(含 0.03%十二烷基硫酸钠 (SDS)]与甲烷气体反应,通过对水合物生成前后溶液中的 Cl-的质量浓度和氢、氧同位素组成的测定,研究了天然气水合物生成过程中氢、氧同位素的分馏情况.实验证明氢、氧的重同位素易于富集在水合物中,其在天然海水-甲烷体系中的分馏系数分别为 1.018～ 1.036和 1.003 4～ 1.006 3,这一分馏系数稍大于前人在纯水和 NaCl溶液中所测得的分馏系数. 相似文献
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异剥橄榄岩化是地幔橄榄岩与硅不饱和熔体发生强烈相互作用的地幔过程。这一过程通常伴随地幔物理-化学性质的显著改变,与克拉通岩石圈减薄和破坏密切相关。本文梳理了前人对异剥橄榄岩化的驱动机理、结构和成分特征及其对大陆稳定性影响等方面的定性认识,并在此基础上通过热力学模拟,刻画了不同属性地幔与熔体在不同温度压力条件下的相互作用过程,目标是为定量限定异剥橄榄岩化的发生条件、物理-化学效应及地球动力学意义。研究显示,异剥橄榄岩化通常会出现磷灰石、角闪石、金云母和碳酸盐等标志性交代矿物,并以斜方辉石被单斜辉石替换为典型特征,还可发育海绵边、熔体囊(已冷却结晶为单斜辉石、橄榄石等细粒矿物)和矿物环带等非平衡结构。热力学模拟表明,熔岩反应过程受原岩、熔体性质以及熔/岩比例的共同控制,不同属性地幔(难熔方辉橄榄岩、饱满二辉橄榄岩)与贫硅(如霞石岩)熔体反应都能生成富单斜辉石橄榄岩,且在较高压力(如2.5GPa和4.0GPa)条件下更容易形成异剥橄榄岩;相比之下,不同性质地幔与富硅(如MORB)熔体反应在任何压力条件下均不能产生异剥橄榄岩。此外,两类熔体参与的熔岩反应均能引起围岩密度逐渐增加,并在高压条件下... 相似文献
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西藏雅鲁藏布江缝合带西段巴尔地幔橄榄岩成因及构造意义 总被引：10，自引：7，他引：3
巴尔蛇绿岩属于雅鲁藏布江缝合带的西延部分,距拉萨约1200km,主要由地幔橄榄岩、少量的橄长堆晶岩和玄武岩组成.地幔橄榄岩主体为合单辉方辉橄榄岩,少量为二辉橄榄岩.根据巴尔蛇绿岩地幔橄榄岩的结构构造特征,将矿物组合划分为3个世代,第一世代残余地幔矿物组合:橄榄石+斜方辉石+单斜辉石;第二世代部分熔融及熔-岩反应矿物组合:橄榄石+斜方辉石+单斜辉石+尖晶石;第三世代地幔交代作用矿物组合,主要为含水矿物角闪石.将3个世代的矿物组合归并为2个演化阶段:第一阶段,包括第一世代和第二世代矿物组合,形成于MOR(mid-ocean ridge)构造环境下的洋脊扩张阶段;第二阶段,为第三世代矿物角闪石,形成于SSZ(super-subduction zone)环境下的俯冲阶段.对比雅鲁藏布江缝合带不同区段蛇绿岩中地幔橄榄岩的特征,发现雅鲁藏布江缝合带存在MOR和SSZ两种类型的蛇绿岩,其中中段的蛇绿岩主要以典型的SSZ型地幔橄榄岩为主,而东、西段则以受到不同程度SSZ环境改造的MOR型地幔橄榄岩为主,认为雅鲁藏布江缝合带蛇绿岩地幔橄榄岩演化分段性的特征,与新特提斯洋沿弧方向上板块活动的动力学机制的不均一有关. 相似文献
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根据X射线衍射(XRD)分析发现: A Fe3(SO4)2(OH)6(A=K+、H3O+)系列铁钒的XRD数据十分相近,难以用XRD区别,需通过能谱(EDS)辅助分析,才能区分此类铁矾。另外,此类铁矾的003和107面网间距d随K+含量增大而增大,且呈一元三次方程的关系;而033和220面网间距d随K+含量增大而减小,呈一元二次方程的关系。对该现象从铁矾晶体结构方面进行解释:K+、H3O+离子位于较大空隙中,且沿着Z轴方向排列,当K+、H3O+离子之间相互替换时,会导致该铁矾晶体结构在Z轴方向有较明显的变化。 相似文献
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Pyromorphite Pb5(PO4)3Cl and mimetite Pb5(AsO4)3Cl are isostructural minerals with apatite. Due to their high environmental stability, they have gained considerable attention as metals sequestration agents in water treatment and contaminated soil remediation. Pyromorphite and mimetite can form a continuous solid solution series in near-Earth surface environments. Precipitation of the end members and intermediate members of the series is likely to occur in the areas where the cost-effective in situ immobilization reclamation method, based on phosphate amendments, is applied. In contrast to the widely studied thermodynamic parameters of pyromorphite and mimetite, knowledge of the thermodynamics of their solid solutions is sparse. To supplement the data, a number of compounds from the pyromorphite-mimetite series were synthesized at room temperature using a method to simulate the conditions in the near-Earth surface environments. Afterwards, batch dissolution and dissolution-recrystallization experiments of seven synthesized precipitates were conducted at 25 °C, pH = 2 and in a 0.05 M KNO3 background electrolyte. The experiments were carried out for a period of 6 (dissolution) and 14 (dissolution-recrystallization) months. A plateau in the [Pb] evolution patterns was used to determine equilibrium. All seven dissolutions were congruent, and the ionic activity products (IAP) of the minerals from the pyromorphite-mimetite solid solution series were calculated based on the dissolution reaction: . The IAPs for pyromorphite and mimetite exhibit a significant difference in values over three orders of magnitude between approximately 10−79 for pyromorphite and approximately 10−76 for mimetite. The series appeared to be ideal, and Lippmann and Roozboom diagrams were used for better understanding of its thermodynamics. The results indicated a strong tendency of pyromorphite to partition into the solid phase in the series, which explains some of the naturally observed phenomena. The improvement of the lattice stability of the mimetite due to isostructural phosphate substitutions in anionic sites was observed. The thermodynamic data reported in this study supplement existing databases used in geochemical modeling. 相似文献
15.
The system CaMgSi2O6CaAl2SiO6CaFeAlSiO6 has been studied in air at 1 atm. The phase assemblage at subsolidus temperatures in the CaMgSi2O6-rich portion is Cpx + An + Mel and that in the CaMgSi2O6-poor portion Cpx + An + Mel + Sp. At subsolidus temperatures the sigle-phase field of clinopyroxene increases with an increase in the CaFeAlSiO6 component of the system. The Al2O3 content of clinopyroxene, however, continues to increase beyond the single-phase field and attains at least 16.04 wt.% Al2O3 with 3.9 wt.% Fe2O3. The stability field of fassaite in the system over a range of pressures and oxygen fugacities has been estimated from data in the literature as well as the present data. The CaFeAlSiO6 content of fassaite is dependent on oxygen fugacity, but is not influenced by pressure. The stability field is strongly influenced by oxygen fugacity at low and high pressure, and decreases with decreasing oxygen fugacity. Clinopyroxenes in both volcanic and metamorphic rocks from various localities, when plotted on the CaMgSi2O6CaAl2SiO6CaFeAlSiO6 triangle, show that there is no compositional gap between diopside and fassaitic pyroxene in metamorphic rocks, and that the fassaitic pyroxene in alkalic rocks becomes richer in both CaAl2SiO6 and CaFeAlSiO5 components as crystallization proceeds. These results agree with those obtained in the experimental study. 相似文献
16.
T. Benjamin W.R. Heuser D.S. Burnett M.G. Seitz 《Geochimica et cosmochimica acta》1980,44(9):1251-1264
Using fission and alpha track radiography techniques, we have measured partition coefficients (D) for the actinide elements Th, U and Pu between diopsidic clinopyroxene, whitlockite [β-Ca3 (PO4)2] and silicate liquid at 20kbar. Equilibrium partitioning at the crystal-liquid interface is assumed, and corrections for actinide zoning have been applied to the measured D values. Reproducibility for both actinide and minor element D values is carefully examined as a criterion for crystal-liquid interface equilibrium. The data are mostly compatible with interface equilibrium except for experiments at high cooling rates ( ? 30 deg/hr). Partition coefficients for Th/U/Pu of about 0.002/0.002/0.06 are measured for clinopyroxene and 1.2/0.5/3.4 for whitlockite. At an oxygen fugacity of 10?8.5, Pu is much more readily incorporated into the crystalline phases than is U or Th because of the importance of trivalent Pu. The DPu(cpx) is similar to D(cpx) of the light rare earths supporting the concept of Pu/(rare earth) dating. 相似文献
17.
The short range distribution of interatomic distances in three feldspar glasses has been determined by X-ray radial distribution analysis. The resulting radial distribution functions (RDF's) are interpreted by comparison with RDF's calculated for various quasi-crystalline models of the glass structure.The experimental RDF's of the alkali feldspar glasses were found to be inconsistent with the four-membered rings of tetrahedra associated with crystalline feldspars; the structures of these glasses are probably based on interconnected six-membered rings of the type found in tridymite, nepheline, or kalsilite. In contrast, the RDF of calcic feldspar glass is consistent with a four-membered ring structure of the type found in crystalline anorthite. T-O bond lengths (T = Si,Al) increase from 1.60 Å in SiO2 glass [J. H. Konnert and J. Karle (1973) Acta Cryst.A29, 702–710] to 1.63 Å in the alkali feldspar glasses to 1.66 Å in the calcic feldspar glass due to the substitution of Al for Si in the tetrahedra] sites. The T-O-T bond angles inferred from the RDF peak positions are 151° in SiO2 glass (see reference above), 146° in the alkali feldspar glasses, and 143° in the calcic feldspar glass. Detail in the RDF at distances greater than 5 Å suggests that the alkali feldspar glasses have a higher degree of long range order than the calcic feldspar glasses.Assuming that the structural details of our feldspar glasses are similar to those of the melts, the observed structural differences between the alkali feldspar and calcic feldspar glasses helps explain the differences in crystallization kinetics of anhydrous feldspar composition melts. Structural interpretations of some thermodynamic and rheologic phenomena associated with feldspar melts are also presented based on these results. 相似文献
18.
I. V. Pekov N. V. Chukanov I. M. Kulikova D. I. Belakovsky 《Geology of Ore Deposits》2007,49(7):530-536
Phosphoinnelite, an analogue of innelite with P > S, has been found in a peralkaline pegmatite vein crosscutting calcite carbonatite
at the phlogopite deposit, Kovdor pluton, Kola Peninsula. Cancrinite (partly replaced with thomsonite-Ca), orthoclase, aegirine-augite,
pectolite, magnesioarfvedsonite, golyshevite, and fluorapatite are associated minerals. Phosphoinnelite occurs as lath-shaped
crystals up to 0.2 × 1 × 6 mm in size, which are combined typically in bunch-, sheaf-, and rosettelike segregations. The color
is yellow-brown, with vitreous luster on crystal faces and greasy luster on broken surfaces. The mineral is transparent. The
streak is pale yellowish. Phosphoinnelite is brittle, with perfect cleavage parallel to the {010} and good cleavage parallel
to the {100}; the fracture is stepped. The Mohs hardness is 4.5 to 5. Density is 3.82 g/cm3 (meas.) and 3.92 g/cm3 (calc.). Phosphoinnelite is biaxial (+), α = 1.730, β = 1.745, and γ = 1.764, 2V (meas.) is close to 90°. Optical orientation
is Z^c ∼ 5°. Chemical composition determined by electron microprobe is as follows (wt %): 6.06 Na2O, 0.04 K2O, 0.15 CaO, 0.99 SrO, 41.60 BaO, 0.64 MgO, 1.07 MnO, 1.55 Fe2O3, 0.27 Al2O3, 17.83 SiO2, 16.88 TiO2, 0.74 Nb2O5, 5.93 P2O5, 5.29 SO3, 0.14 F, −O=F2 = −0.06, total is 99.12. The empirical formula calculated on the basis of (Si,Al)4O14 is (Ba3.59Sr0.13K0.01)Σ3.73(Na2.59Mg0.21Ca0.04)Σ3.04(Ti2.80Fe
0.26
3+
Nb0.07)Σ3.13[(Si3.93Al0.07)Σ4O14(P1.11S0.87)Σ1.98O7.96](O2.975F0.10)Σ3.075. The simplified formula is Ba4Na3Ti3Si4O14(PO4,SO4)2(O,F)3. The mineral is triclinic, space group P
or P1. The unit cell dimensions are a = 5.38, b = 7.10, c = 14.76 ?; α = 99.00°, β = 94.94°, γ = 90.14°; and V = 555 ?3, Z = 1. The strongest lines of the X-ray powder pattern [d, ? in (I)(hkl)] are: 14.5(100)(001), 3.455(40)(103), 3.382(35)(0
2), 2.921(35)(005), 2.810(40)(1
4), 2.683(90)(200,
01), 2.133(80)(
2), 2.059(40)(204, 1
3, 221), 1.772(30)(0
1, 1
7, 2
2, 2
3). The infrared spectrum is demonstrated. An admixture of P substituting S has been detected in the innelite samples from
the Inagli pluton (South Yakutia, Russia). An innelite-phosphoinnelite series with a variable S/P ratio has been discovered.
The type material of phosphoinnelite has been deposited at the Fersman Mineralogical Museum, Russian Academy of Sciences,
Moscow.
Original Russian Text ? I.V. Pekov, N.V. Chukanov, I.M. Kulikova, D.I. Belakovsky, 2006, published in Zapiski Rossiiskogo
Mineralogicheskogo Obshchestva, 2006, No. 3, pp. 52–60.
Considered and recommended by the Commission on New Minerals and Mineral Names, Russian Mineralogical Society, May 9, 2005.
Approved by the Commission on New Minerals and Mineral Names, International Mineralogical Association, July 4, 2005 (proposal
2005-022). 相似文献
19.
The cumulative association constant (β2) for the geochemically important aqueous complex UO2[HPO4]2?2 has been determined by potentiometric titration in Na2HPO4-UO2(NO3)2 solutions in the pH range 3.9–4.7, at ionic strengths below 0.024 molal with the Newton-Raphson method used to compute β2 from the chemical analytical data. Based on 25 measurements we obtain logβ2 = 18.3 ± 0.2 at 25°C. From the same experiments we compute that the association constant of UO2OH+ is 8.9 ± 0.1, in disagreement with the value of 8.3 ± 0.3 for this constant given by Baes and Mesmer (1976). 相似文献
20.
利用混合气体的标准样品对激光拉曼探针进行标定,可以快速准确地对包裹体中的无机及有机气相组分进行定量分析。而常用的商用钢瓶装混合气体标样,存在费用高、气体组成单一固定等缺点。本文设计了一套在线标样制备装置,提出一种在线配置不同浓度和压力条件下混合气体标样的方法。利用高纯度(纯度99.999%)的N2、CH4以及CO2钢瓶气,经过在线混合增压,在5 MPa和10 MPa条件下制备了N2摩尔分数为30%、50%和70%的N2-CH4以及N2-CO2混合气体在线标样。该方法制备的标样与70%N2+30%CO2的商用钢瓶气标样对比表明,CO2与N2的拉曼相对峰高以及相对峰面积值的误差在4%以内,具有较高的准确度和重现性。通过不同压力和浓度条件下CH4以及CO2的拉曼相对定量因子测定表明,气体的相对定量因子在5~10 MPa压力条件下与压力及组成无关。地质样品应用结果表明,本方法可以方便、灵活、准确地按任意比例将两瓶及两瓶以上纯气体钢瓶样品进行混合及增压,为激光拉曼标定、气体组成原位测量等提供了一种新的技术思路。 相似文献