溶胶－凝胶方法制取纳米级超导物质的研究

当前对超导物质的研究都集中于高临界温度的超薄型物质的研究上，本研究通过相对简单的方法获得高纯度的纳米级的钙钛矿型超导物质，其过程为：通过溶胶－凝胶方法合成一种含有Ｌａ和Ｎｉ的高纯度的有机物，然后利用天然蒙脱石的离子交换性将上述化合物渗入到其含水层中以获得超薄型的超导物质     

煤显微组分分离富集

单组分成烃热模拟实验已成为煤成烃研究的重要组成部分，煤显微组分分离是上述研究的重要前提。实验结果证明：单纯应用某一种方法效果往往不佳，而采用人工碎样→筛选法→浮选法（沉淀法）→高速离心法这一综合的显微组分分离方法，则可以获得高纯度的显微组分。     

克拉通岩石圈三维物质架构示踪方法

克拉通岩石圈三维物质组成架构示踪是当今地球科学研究前沿，面临系列挑战。在对已有相关成果系统梳理的基础上，分别阐述了实现由点到面、由局部到全时空、由单一方法到多学科综合约束3个战略思路转变的基本要点；并以华北克拉通为例，提出了亟待深化的研究领域和未来方向。多种地球物理方法联立约束和综合解释，不仅开拓了岩石圈物质组成研究的新思路，而且有利于获得更可信的结果。逼近实际的岩石圈物质组成架构必须符合岩石探针、岩石圈物性结构、岩石物理性质与矿物及化学组成的测试分析/模拟计算结果等观测事实，并遵循地球化学热力学-地球动力学理论框架；这就需克服单一资料和方法各自的局限性，由单一手段向多方法综合约束转变，实现多学科融合来开展岩石圈物质组成的研究。据此提出“循序渐进、逐步深化”和“反馈修正、不断逼近”的岩石圈物质组成架构的多学科综合示踪研究流程。华北克拉通岩石圈三维物质架构研究的重点在于通过多学科的深度融合，恢复不同时期的构造格架和对应的物质组成，示踪其岩石圈物质架构的演变过程。     

微量热法用于矿物溶解反应实验研究

0 前言 在地质地球化学领域中,研究矿物溶解和水岩作用反应一直是科学工作者密切关注的问题.人们研究这类现象更多的是采用传统的化学分析方法,即在一定时间间隔内对反应体系中的物质成分做化学分析,通过物质浓度的变化寻找其化学动力学规律.这类研究方法属于静态法研究范畴,能够获得的信息有限,操作过程较为烦琐,并且需要耗费大量的时间和人力财力.     

揭示三维岩石圈物质架构的技术方法体系框架

长期以来，岩石圈深部探测主要依赖地球物理手段和深部钻探，缺乏深部物质探测技术。对深部物质的了解也主要局限于两种途径：一类是地球物理推测方法，依据地表获得的深部岩石的物性测定，解释或推测深部物质的某些特征；另一类是捕虏体方法(Xenolith- based methodology)，直接获取深部物质信息。本文重点探索的第三种途径，即充分利用地表出露的岩浆岩，通过岩石探针和同位素填图，示踪深部物源(物质)特征。特别是利用大数据分析和数字填图，了解深部物质三维架构及四维演变。在此基础上，总结上述三种途径，构建较完整的以岩石探针和同位素填图为核心的揭示岩石圈三维物质组成架构的方法体系。研究显示，在岩相学研究的基础上，通过系统开展Sr、Nd、Hf、Pb等多元同位素示踪填图，结合地球物理资料，可有效揭示岩石圈深部物质组成架构。通过中亚增生造山带(北疆)、青藏高原碰撞造山带(冈底斯- 三江)和华北- 扬子克拉通三个典型大地构造单元关键地区的实践，显示多元同位素示踪深部物质的一致性和有效性，以及同位素填图结果与地球物理探测结果的对应性。基于这些成果，笔者初步提出了揭示岩石圈三维物质组成架构的方法体系框架。该方法体系具有良好应用前景，有望成为与地球物理探测相结合和匹配的深部物质架构探测技术，为规范开展深部物质架构探测、物质演变过程及深部动力学过程研究提供技术支撑。     

我国首次钻获高纯度新类型“可燃冰”

近日,我国海洋地质科技人员在广东沿海珠江口盆地东部海域首次钻获高纯度天然气水合物（俗称“可燃冰”）样品,并通过钻探获得可观的控制储量。     

煤结构研究的新手段—扫描隧道显微镜的原子力显微镜

扫描隧道显微镜和原子力显微镜是新发展起来的物质表面分析仪器，由于具有极高的分辨率而被应用于很多研究领域，本文将其引入到煤结构的结构中，并获得了意义的结果。它们作为一种重要的研究手段，与透射电子显微镜等方法相互补充，对探讨煤的形成与演变机制有重要的意义。     

川西雅江晚三叠世复理石盆地砂岩特征

雅江三叠纪复理石盆地是巴颜喀拉海盆的重要组成部分，晚三叠世沉积了厚度巨大的复理石地层，其中砂岩属特征夹层。根据1：25万区域地质调查资料和剖面研究，在详细观察描述砂岩宏观特征的基础上，通过薄片鉴定等方法，详细研究了其物质成分及结构特征，指出其成分成熟度为中等至较高，结构成熟度较低，探讨了砂岩的物质来源。     

高原黄土Sr、CaO的古气候意义以及记录的环境变化

青藏高原东北部的西宁盆地紧邻柴达木盆地戈壁沙漠，沉积了厚层的、序列完整的黄土物质，对其进行研究可望得到高原古气候演化信息。通过对西宁盆地盘子山黄土剖面酸溶相Sr,CaO含量变化的测试分析，获得了自末次间冰期以来多次不同时间尺度变化的信息，证明Sr,CaO可以作为该地区黄土研究更为灵敏的气候代用指标。     

原地宇宙成因核素暴露测年方法中石英的提取

原地宇宙成因核素10Be和26Al的暴露年龄测定是近年来发展较快的测年技术,已在地学研究中得到广泛应用。该方法需要选用经一系列前处理过程获得的纯净石英作为待测样品,制备成BeO和Al2O3以供加速器质谱仪测量。因此获得高纯度的石英样品,是该测年方法的关键环节之一。本研究在已有报道的石英提纯化学流程的基础上,尝试对流程进行部分优化,通过实验对比不同粒径组分、不同固液比水浴振荡器和滚筒HF-HNO3蚀刻效果,确定使用HF-HNO3(1%或2%,固液比15.0 g/L)滚筒加热法刻蚀样品以去除铝硅酸盐,多钨酸钠重液分离样品中的石英和其他组分。优化的分离纯化流程应用于处理采自祁连山北缘河流阶地含石英的岩石样品,经纯化的石英纯度可达98%以上,Al的含量小于200μg/g,表明采用优化的提取流程获得了高纯度的石英样品,可以满足10Be和26Al暴露测年所需样品要求。     

X射线荧光光谱熔融片法测定超导材料原子数配比

报道了用Ｘ射线荧光光谱测定铋钾钡系超导材料原子配比的方法。测量样片用熔融法制备，测定各组分的质量分数后计算原子配比并推出材料的分子式。     

Dissociation kinetics of Fe(III)- and Al(III)-natural organic matter complexes at pH 6.0 and 8.0 and 25 °C

The rate at which iron- and aluminium-natural organic matter (NOM) complexes dissociate plays a critical role in the transport of these elements given the readiness with which they hydrolyse and precipitate. Despite this, there have only been a few reliable studies on the dissociation kinetics of these complexes suggesting half-times of some hours for the dissociation of Fe(III) and Al(III) from a strongly binding component of NOM. First-order dissociation rate constants are re-evaluated here at pH 6.0 and 8.0 and 25 °C using both cation exchange resin and competing ligand methods for Fe(III) and a cation exchange resin method only for Al(III) complexes. Both methods provide similar results at a particular pH with a two-ligand model accounting satisfactorily for the dissociation kinetics results obtained. For Fe(III), half-times on the order of 6-7 h were obtained for dissociation of the strong component and 4-5 min for dissociation of the weak component. For aluminium, the half-times were on the order of 1.5 h and 1-2 min for the strong and weak components, respectively. Overall, Fe(III) complexes with NOM are more stable than analogous complexes with Al(III), implying Fe(III) may be transported further from its source upon dilution and dispersion.     

Uranyl adsorption onto montmorillonite: Evaluation of binding sites and carbonate complexation

The fate and transport of uranium in contaminated soils and sediments may be affected by adsorption onto the surface of minerals such as montmorillonite. Extended X-ray absorption fine structure (EXAFS) spectroscopy has been used to investigate the adsorption of uranyl (UO₂²⁺) onto Wyoming montmorillonite. At low pH (∼4) and low ionic strength (10⁻³ M), uranyl has an EXAFS spectrum indistinguishable from the aqueous uranyl cation, indicating binding via cation exchange. At near-neutral pH (∼7) and high ionic strength (1 M), the equatorial oxygen shell of uranyl is split, indicating inner-sphere binding to edge sites. Linear-combination fitting of the spectra of samples reacted under conditions where both types of binding are possible reveals that cation exchange at low ionic strengths on SWy-2 may be more important than predicted by past surface complexation models of U(VI) adsorption on related montmorillonites. Analysis of the binding site on the edges of montmorillonite suggests that U(VI) sorbs preferentially to [Fe(O,OH)₆] octahedral sites over [Al(O,OH)₆] sites. When bound to edge sites, U(VI) occurs as uranyl-carbonato ternary surface complexes in systems equilibrated with atmospheric CO₂. Polymeric surface complexes were not observed under any of the conditions studied. Current surface complexation models of uranyl sorption on clay minerals may need to be reevaluated to account for the possible increased importance of cation exchange reactions at low ionic strengths, the presence of reactive octahedral iron surface sites, and the formation of uranyl-carbonato ternary surface complexes. Considering the adsorption mechanisms observed in this study, future studies of U(VI) transport in the environment should consider how uranium retardation will be affected by changes in key solution parameters, such as pH, ionic strength, exchangeable cation composition, and the presence or absence of CO₂.     

Cation hydrolysis and the regulation of trace metal composition in seawater

Thermodynamic calculations have been performed for cation hydrolysis, including temperatures from 2°C to the high values of significance near Mid-Oceanic Ridge Systems (MORS). Eighteen elements with wide range of residence times (t) in seawater (Mn, Th, Al, Bi, Ce, Co, Cr(III), Fe, Nd, Pb, Sc, Sm, Ag, Cd, Cu, Hg, Ni and Zn) have been considered. A model for the regulation of trace metal composition in seawater by cation hydrolytic processes, including those at MORS, is presented. Results show an increase in the abundance of neutral metal hydroxyl species with increase in temperature. During hydrothermal mixing, as the temperature increases, transformation from lower positive hydroxyl complexes to higher or neutral complexes would occur for Cd, Ce, Co, Cr(III), Cu, Mn, Nd, Ni, Pb, Sm and Zn. pH values for adsorption of the metal ion onto solid surfaces have direct relation with pH values of hydrolysis. Co, Mn and Pb could be oxidized to higher states (at Mn-oxide surfaces) that would occur even at MORS. Ce can also be oxidized at 25°C. Solubility calculations show that Al, Bi, Cr(III), Sc, Fe and Th are saturated while Ce, Nd and Sm are not with respect to their oxyhydroxide solids at their concentrations in seawater at 25°C. Cu, Hg, Ni and Zn reach saturation equilibrium at 250°C, whereas Co, Mn and Pb exhibit unsaturation. The results suggest an increase in scavenging capacity of a cation with rise in temperature.     

Goethite adsorption of Cu(II), Pb(II), Cd(II), and Zn(II) in the presence of sulfate: Properties of the ternary complex

Adsorption of Cu²⁺, Zn²⁺, Cd²⁺, and Pb²⁺ onto goethite is enhanced in the presence of sulfate. This effect, which has also been observed on ferrihydrite, is not predicted by the diffuse layer model (DLM) using adsorption constants derived from single sorbate systems. However, by including ternary surface complexes with the stoichiometry FeOHMSO₄, where FeOH is a surface adsorption site and M²⁺ is a cation, the effect of SO₄²⁻ on cation adsorption was accurately predicted for the range of cation, goethite and SO₄²⁻ concentrations studied. While the DLM does not provide direct molecular scale insights into adsorption reactions there are several properties of ternary complexes that are evident from examining trends in their formation constants. There is a linear relationship between ternary complex formation constants and cation adsorption constants, which is consistent with previous spectroscopic evidence indicating ternary complexes involve cation binding to the oxide surface. Comparing the data from this work to previous studies on ferrihydrite suggests that ternary complex formation on ferrihydrite involves complexes with the same or similar structure as those observed on goethite. In addition, it is evident that ternary complex formation constants are larger where there is a stronger metal-ligand interaction. This is also consistent with spectroscopic studies of goethite-M²⁺-SO₄²⁻ and phthalate systems showing surface species with metal-ligand bonding. Recommended values of ternary complex formation constants for use in SO₄-rich environments, such as acid mine drainage, are presented.     

Surface complexation and precipitate geometry for aqueous Zn(II) sorption on ferrihydrite: II. XANES analysis and simulation

X-ray absorption near-edge spectroscopy (XANES) analysis of sorption complexes has the advantages of high sensitivity (10- to 20-fold greater than extended X-ray absorption fine structure [EXAFS] analysis) and relative ease and speed of data collection (because of the short k-space range). It is thus a potentially powerful tool for characterization of environmentally significant surface complexes and precipitates at very low surface coverages. However, quantitative analysis has been limited largely to “fingerprint” comparison with model spectra because of the difficulty of obtaining accurate multiple-scattering amplitudes for small clusters with high confidence.In the present work, calculations of the XANES for 50- to 200-atom clusters of structure from Zn model compounds using the full multiple-scattering code Feff 8.0 accurately replicate experimental spectra and display features characteristic of specific first-neighbor anion coordination geometry and second-neighbor cation geometry and number. Analogous calculations of the XANES for small molecular clusters indicative of precipitation and sorption geometries for aqueous Zn on ferrihydrite, and suggested by EXAFS analysis, are in good agreement with observed spectral trends with sample composition, with Zn-oxygen coordination and with changes in second-neighbor cation coordination as a function of sorption coverage. Empirical analysis of experimental XANES features further verifies the validity of the calculations. The findings agree well with a complete EXAFS analysis previously reported for the same sample set, namely, that octahedrally coordinated aqueous Zn²⁺ species sorb as a tetrahedral complex on ferrihydrite with varying local geometry depending on sorption density. At significantly higher densities but below those at which Zn hydroxide is expected to precipitate, a mainly octahedral coordinated Zn²⁺ precipitate is observed. An analysis of the multiple scattering paths contributing to the XANES demonstrates the importance of scattering paths involving the anion sublattice. We also describe the specific advantages of complementary quantitative XANES and EXAFS analysis and estimate limits on the extent of structural information obtainable from XANES analysis.     

Significance of Europium anomalies in silicate melts and crystal-melt equilibria: a re-evaluation

Although europium speciation in silicate melts partly reflects prevailing oxygen fugacities, melt composition and structure play the major role in determining Eu²⁺/ Eu³⁺ ratios and europium partitioning into mineral phases. Experimental evidence by different investigators on the magnitude of the compositional effect on Eu²⁺/Eu³⁺ provides consistent results only if account is taken of the oxygen buffer system employed in the experiments. The medium-dependent reduction of europium can be understood in terms of the preferential stabilization of Eu²⁺ by a strong aluminosilicate complex in the melt phase, and to a much lesser degree by metasilicate complexes. The stability of these complexes increases as the field strength of the associated cation species decreases. Hence Eu²⁺-aluminosilicate complexes are preferentially stabilized relative to trivalent lanthanides in melts of appropriate composition and their presence minimizes the enthalpy of the melt. The influence of these complexes is particularly pronounced in melts with a high feldspathic component and a strongly polymerized structure. Their petrogenetic influence is best documented through the behaviour of europium relative to the other lanthanides during anhydrous anatexis in high-grade metamorphic terrains and in the anomalous europium partition coefficients of phenocryst phases which formed during the crystallization of highly silicic magmas.     

Constraints on anthophyllite formation in thermally metamorphosed peridotites from southwestern Japan

Anthophyllite or another species of Mg‐amphibole commonly occurs in an intervening zone between the higher grade orthopyroxene zone and lower grade talc zone in progressively metamorphosed peridotites. However, the anthophyllite zone is absent in some of the thermally metamorphosed peridotite complexes in SW Japan despite the existence of the other zones. A comparative study presented here reveals similarities in rock composition and metamorphic pressure–temperature conditions at high‐grade zones between the metaperidotite complexes, and differences in the following respects. The metaperidotite complex that contains an anthophyllite zone has less abundant magnetite and olivine that is more homogeneous than the complex where the anthophyllite zone is absent. It is likely that the degree of cation diffusion in olivine crystals depends on duration of heat retention in metaperidotites during thermal metamorphism, which is supported by the variation in mineralogy of intrusive rocks and pelitic hornfelses surrounding the metaperidotites, and by calculations based on a simplified model of thermal conduction. The long duration of heat retention looks to be a necessary condition for the formation of anthophyllite crystals, which have a sluggish nucleation rate. In addition, the circulation of reducing fluids during prolonged metamorphism likely promoted the decomposition of magnetite and the growth of anthophyllite, into which iron is preferentially distributed. This study cautions about kinetic controls and redox conditions for anthophyllite formation in metaperidotites.