A probabilistic parametrization for geological uncertainty estimation using the ensemble Kalman filter (EnKF)

In the past years, many applications of history-matching methods in general and ensemble Kalman filter in particular have been proposed, especially in order to estimate fields that provide uncertainty in the stochastic process defined by the dynamical system of hydrocarbon recovery. Such fields can be permeability fields or porosity fields, but can also fields defined by the rock type (facies fields). The estimation of the boundaries of the geologic facies with ensemble Kalman filter (EnKF) was made, in different papers, with the aid of Gaussian random fields, which were truncated using various schemes and introduced in a history-matching process. In this paper, we estimate, in the frame of the EnKF process, the locations of three facies types that occur into a reservoir domain, with the property that each two could have a contact. The geological simulation model is a form of the general truncated plurigaussian method. The difference with other approaches consists in how the truncation scheme is introduced and in the observation operator of the facies types at the well locations. The projection from the continuous space of the Gaussian fields into the discrete space of the facies fields is realized through in an intermediary space (space with probabilities). This space connects the observation operator of the facies types at the well locations with the geological simulation model. We will test the model using a 2D reservoir which is connected with the EnKF method as a data assimilation technique. We will use different geostatistical properties for the Gaussian fields and different levels of the uncertainty introduced in the model parameters and also in the construction of the Gaussian fields.     

燕山期高原——一种新构想

<正> 基于火成岩及变质岩和古地磁等的研究成果,吴根耀等认为苏皖地块是特提斯演化阶段一个独立的构造单元。由于苏鲁洋在晚侏罗世—早白垩世最终闭合,苏皖地块与华北克拉通发生碰撞,因而形成了中国东部蔚为壮观的燕山期造山系及燕山期高原(图1)。该高原的北缘是发育于冀北—内蒙的宽阔近东西向的冲断-推覆构造带,即燕山—阴山逆冲-推覆构造带;在其以     

我国新能源发展障碍与应对:全球现状评述

以化石能源为主的能源消费模式已经难以满足可持续发展的要求, 改善能源消费结构、减少对化石能源的依赖势在必行。在此背景下, 发展环境友好、地域分布相对均衡且潜力无限的新能源成为各国共识。新能源包括太阳能、风能、生物质能、地热能、海洋能、氢能、天然气水合物、核能、核聚变能等共9种类型。由于种类繁多、资源禀赋和物化特征差异悬殊, 开发利用新能源需要面对比化石能源复杂得多的规划、管理和技术问题。如果措施不当, 不但会造成经济损失, 而且可能会威胁到人类安全。在全面深入了解全球新能源发展现状的基础上, 认真总结各国经验教训, 制定合理的发展战略, 是开发利用新能源的先行性工作, 具有重要意义。本文对国内外新能源资源情况、技术水平、总体发展现状进行分析, 并对我国新能源发展过程中的制约因素进行深入剖析, 结合我国国情提出新能源发展的对策建议。     

Cobalt(II) interactions with near-coastal marine sediments

Chemical speciation of trace metals in aqueous systems is determined by a variety of competitive reactions. Sediments act as sinks for many trace elements, forming surface complexes and otherwise surface-related compounds. Reactions between dissolved trace metals and functional groups at sediment surfaces can be described as coordination reactions similar to those occurring in solution.Factors inherent to both sediment and solution influence the trace metal speciation. These factors include pH, type of mineral, surface area and/or density of reactive surface sites, complexing ligands, and competing ions. The relative importance of some of these factors was studied using an isotope dilution technique. Coastal sediment samples from the Gulf of Mexico were used as the solid matrix. Models developed for pure minerals were used here to (empirically) describe the complex assemblages of minerals in the natural sediment samples.The adsorption experiments showed that cobalt uptake by marine sediment samples followed a two-step time dependency. The initial fast step lasted about five to ten days and the subsequent slow step continued after more than 100 d of equilibration. The pseudoequilibrium reached during the fast step was modeled with an equilibrium model, while the twostep behavior was modeled with a time-dependent model. The two models are related by the reaction stoichiometries. It is believed that the experimental as well as the modeling approach taken in this study, although empirical when used for natural settings, is much more powerful than the use of traditional means to describe trace element interactions with natural solid phases.     

Water-rock-tailings interactions and sources of sulfur and metals in the subtropical mining region of Taxco,Guerrero (southern Mexico): A multi-isotopic approach

Multi-isotope (H, O, S, Sr, Pb) systems coupled with conventional (major and trace element) hydrogeochemical analysis were applied to determine the origin of water, to model water-rock-tailings interactions and for source apportionment of sulfur and associated toxic metals in the mining region of Taxco, Guerrero in southern Mexico. Oxygen and H isotopes indicate that meteoric water in the zone is rainwater undergoing varying degrees of isotopic fractionation by atmospheric evaporation whereas Sr isotopes trace the interaction of pristine water from volcanics of the regional recharge zone and subsequently flowing through sandstone and shale to spring points. Leachates form from two distinctive sources (spring water and surface water) having differential interactions with bedrocks prior to entering the tailings. Compared to pristine water, leachates are enriched in sulfate, metals (e.g. Fe, Mn, Pb and Zn) and metalloids (e.g. As). The sulfur isotopic composition of ore-sulfides, leachates, secondary precipitates, regional surface water and hypogenic sulfates is described in terms of a two-component mixing model with shale of Mexcala and limestone of Morelos formations representing the light and heavy end-members, respectively, whereas Sr isotopic composition is bracketed combining three lithogenic (Mexcala/Morelos, Tilzapotla and Taxco Schist) sources. Finally, leachates have a mixture of lead from ore-sulfides and Taxco Schist Formation (Family I) or from ore-sulfides alone (Family II). The application of multiple environmental isotopic techniques is an outstanding tool for elucidating complex interactions of water with bedrocks and tailings and for determining the source of sulfur and toxic metal from mining and other metal polluted environments.     

Magmatic residence times of zoned phenocrysts: introduction and application of the binary element diffusion modelling (BEDM) technique

This paper describes a general technique, binary element diffusion modelling (BEDM), for determining single-crystal residence times in magmas that relies on modelling the diffusion of two or more elements in the crystal. BEDM has the advantage over other diffusion-based models in that it does not need a precisely defined initial compositional profile for the crystal at “zero time”, and instead requires that the concentrations of the two elements are correlated during crystallisation. Any differences subsequently observed between the two elements are caused by intracrystalline diffusion during residence in hot magma. These differences are removed by artificially ageing the slower-diffusing of the two elements, and the amount of time taken to “undo” the difference between the elements is simply related to the crystal residence time (=decoupling time) at high temperatures. The BEDM principle is demonstrated using artificial data and is then applied to literature data for Sr and Ba in a zoned sanidine crystal from the Bishop Tuff (Anderson et al., in J. Petrol 41(3):449–473, 2000). For this crystal, the method gives a residence time estimate of 114 ka at 800°C, which is then compared with estimates from other methods. In theory, the method can be further expanded for use as a geothermometer as well as geochronometer. However, this is not easily possible with the diffusivity data currently available.     

Dynamical study of the wide visual binary ADS 12815 (16 Cyg)

A homogeneous series of photographic position measurments of the visual binary ADS 12815 obtained on the 26-inch refractor of the Pulkovo Observatory (1960–2007) is analyzed. The Pulkovo observations allow for the existence of the planet around component B discovered by Cochran et al. based on radial-velocity measurements. The orbit of the planet must be steeply inclined to the plane of the sky (i ≥ 70°). Uniform series of position measurements obtained at the Dearborn Observatory, US Naval Observatory, and Pulkovo Observatory, the HIPPARCOS parallax, and the relative radial velocities obtained by Hauser and Marcy at the Lick Observatory are used to calculate the elements of possible orbits for the ADS 12815 stars using the apparent motion parameters method. The corresponding periods are more than 20 000 yr, the semi-major axes more than 900 AU, and the eccentricities more than 0.65. All possible orbits are steeply inclined to the Galactic plane. The obtained family of orbits is in better agreement with observations than the family calculated by Hauser and Marcy.     

Iron (III)-silica interactions in aqueous solution: insights from X-ray absorption fine structure spectroscopy

The influence of aqueous silica on the hydrolysis of iron(III) nitrate and chloride salts in dilute aqueous solutions (m_Fe ∼ 0.01 mol/kg) was studied at ambient temperature using X-ray absorption fine structure (XAFS) spectroscopy at the Fe K-edge. Results show that in Si-free iron nitrate and chloride solutions at acid pH (pH < 2.5), Fe is hexa-coordinated with 6 oxygens of H₂O- and/or OH-groups in the first coordination sphere of the metal, at an Fe-O distance of 2.00 ± 0.01 Å. With increasing pH (2.7 < pH < 13), these groups are rapidly replaced by bridging hydroxyls (-OH-) or oxygens (-O-), and polymerized Fe hydroxide complexes form via Fe-(O/OH)-Fe bonds. In these polymers, the first atomic shell of iron represents a distorted octahedron with six O/OH groups and Fe-O distances ranging from 1.92 to 2.07 Å. The Fe octahedra are linked together by their edges (Fe-Fe distance 2.92-3.12 Å) and corners (Fe-Fe distance ∼3.47 ± 0.03 Å). The Fe-Fe coordination numbers (N_edge = 1-2; N_corner = 0.5-0.7) are consistent with the dominant presence of iron dimers, trimers and tetramers at pH 2.5 to 2.9, and of higher-polymerized species at pH > 3.At pH > 2.5 in the presence of aqueous silica, important changes in Fe(III) hydrolysis are detected. In 0.05-m Si solutions (pH ∼ 2.7-3.0), the corner linkages between Fe octahedra in the polymeric complexes disappear, and the Fe-Fe distances corresponding to the edge linkages slightly increase (Fe-Fe_edge ∼ 3.12-3.14 Å). The presence of 1 to 2 silicons at 3.18 ± 0.03 Å is detected in the second atomic shell around iron. At basic pH (∼12.7), similar structural changes are observed for the iron second shell. The Fe-Si and Fe-Fe distances and coordination numbers derived in this study are consistent with (1) Fe-Si complex stoichiometries Fe₂Si_1-2 and Fe₃Si_2-3 at pH < 3; (2) structures composed of Fe-Fe dimers and trimers sharing one or two edges of FeO₆-octahedra; and (3) silicon tetrahedra linked to two neighboring Fe octahedra via corners. At higher Si concentration (0.16 m, polymerized silica solution) and pH ∼ 3, the signal of the Fe second shell vanishes indicating the destruction of the Fe-Fe bonds and the formation of different Fe-Si linkages. Moreover, ∼20 mol.% of Fe is found to be tetrahedrally coordinated with oxygens in the first coordination shell (R_Fe-O = 1.84 Å). This new finding implies that Fe may partially substitute for Si in the tetrahedral network of the silica polymers in Si-rich solutions.The results of this study demonstrate that aqueous silica can significantly inhibit iron polymerization and solid-phase formation, and thus increase the stability and mobility of Fe(III) in natural waters. The silica “poisoning” of the free corner sites of iron-hydroxide colloids should reduce the adsorption and incorporation of trace elements by these colloids in Si-rich natural waters.     

Excess heat capacity and entropy of mixing in the high-structural state (K,Ca)-feldspar binary

Low- and high-temperature heat capacities were measured for a series of synthetic high-structural state (K,Ca)-feldspars (Or–An) using both a relaxation and a differential scanning calorimeter. The data were collected at temperatures between 5 and 800 K on polycrystalline samples that had been synthesised and characterised in a previous study. Below T = 300 K, Or₉₀An₁₀, and Or₈₀An₂₀ showed excess heat capacities of mixing with maximum values of ~3 J mol⁻¹ K⁻¹. The other members of this binary (An > 20 mol%) had lower excess heat capacity values of up to ~1 J mol⁻¹ K⁻¹. Above T = 300 K, some compositions exhibited negative excess heat capacities of mixing (with maximum values of −2 J mol⁻¹ K⁻¹). The vibrational entropy at 298.15 K for Or₉₀An₁₀ and Or₈₀An₂₀ deviated strongly from the behaviour of a mechanical mixture, with excess entropy values of ~3.5 J mol⁻¹ K⁻¹. More An-rich members had only small excess vibrational entropies at T = 298.15 K. The difference in behaviour between members with An > 20 mol% and those with An ≤ 20 mol% is probably a consequence of the structural state of the (K,Ca)-feldspars, i.e., (K,Ca)-feldspars with An ≤ 20 mol% have monoclinic symmetry, whereas those with An > 20 mol% are triclinic. At T = 800 K, the vibrational entropy values were found to scatter around the values expected for a mechanical mixture and, thus, correspond to a quasi-ideal behaviour. The solvus for the (K,Ca)-feldspar binary was calculated based on the entropy data from this study in combination with enthalpy and volume of mixing data from a previous study.     

临界区流体与矿物和岩石在地球内部极端条件下的反应

极端条件下水热化学反应是一个新的科学问题。借助于高温超高压原位直接测量方法、各种谱学方法和同步辐射光源技术研究地球内部流体物质相互作用,可以获得反应过程的产物的分子-原子尺度信息,这些信息可以提供认识极端条件下水和矿物(岩石)反应动力学的新实验途径。地球内部的流体性质随所处高温高压条件发生变化。水的密度、介电常数等物理参数随温度压力变化而改变,在临界态会出现突变。水的性质的剧变会影响水与岩石(矿物)相互作用。文中报道了在极端条件下(20～435℃和23～35MPa)实验测量矿物(钠长石、辉石、石英和阳起石等)和岩石(玄武岩、正长岩)在水溶液里的溶解反应速率的研究结果,发现矿物里各种不同类型金属离子与水反应的速率不同,随温度变化而改变。在升温过程中,进入临界态时,矿物(岩石)与水反应出现一次反应速率的涨落。在恒压升温过程中(临界压力,或略高于临界压力),硅酸盐矿物溶解速率会逐步升高,如硅近临界区(300℃)抵达最大值,然后随升温溶解反应速率减低。地球内部的流体由深处上升到浅处,会从超临界区域进入近临界的气与液的两相不混溶区域。含金属流体里的金属会在气相与液相分离时出现再分配。实验表明:金属Au、Cu、Sn、W、Zn会进入气相,气体可以迁移金属。事实说明:地球内部流体结构和性质从深到浅在不断变化,在跨越临界区时的水的性质异常变化会导致水与矿物(岩石)反应动力学涨落,并且促使金属在临界区出现沉淀和在气液相分离过程中进行再分配及迁移。     

Adsorption isotherm models and error analysis for single and binary adsorption of Cd(II) and Zn(II) using leonardite as adsorbent

Leonardite, a by-product from coal mines, was applied to adsorb Cd(II) and Zn(II) from aqueous solutions. Individual and simultaneous adsorptions of the two metal ions were investigated. In a single-component adsorption system, Langmuir and Freundlich isotherms were fitted to the adsorption data. Linear and nonlinear regression methods were used for the assessment of the optimum adsorption isotherm. Error functions including root-mean-square error, sum of the squares of the errors, mean absolute percentage error, Marquardt’s percent standard deviation (MPSD), and Chi-square were applied in the nonlinear regression. The most suitable model for the adsorption of Cd(II) and Zn(II) in the single system is the Freundlich isotherm. The isotherm parameters calculated by MPSD provided the lowest sum of normalized error (SNE) value. The adsorption capacity was found to be 23.89 mg/g for Cd(II) and 16.86 mg/g for Zn(II). It was observed that the adsorption of Cd(II) on leonardite is greater than that of Zn(II). For binary component adsorption systems, Cd(II) and Zn(II) showed antagonistic behavior. The presence of the other metal ions could decrease the amount of metal adsorbed. Binary adsorption of Cd(II) and Zn(II) was tested with regard to four multi-component isotherms: Extended Langmuir, Modified Langmuir, Sheindorf–Rebuhn–Sheintuch, and Extended Freundlich. The Extended Freundlich isotherm proved to be a good fit for the experimental data.     

Seawater-sediment-basalt interactions: stable isotope (H,O) and elemental fluxes within the Ordovician volcano-sedimentary sequence of Erquy (Brittany,France)

The Ordovician volcano-sedimentary succession of Erquy (northern Brittany) is made of immature sediments thermally metamorphosed at the contact of intruding basic sills. Pillow lavas constitute the upper part of the sequence. The trace element geochemistry of sills and pillow lavas suggests that they were derived from a tholeiitic source located beneath a passive margin. This volcanic sequence was metamorphosed under low to moderate greenschist facies conditions. In this study the direction and amplitude of chemical and isotopic fluxes in the basalt-sediment-water system were established and the oxygen and hydrogen isotope compositions of the aqueous fluid that reacted with the volcanic rocks were characterized. Cationic thermometry on chlorites and isotopic thermometry on plagioclase-chlorite pairs indicate closure metamorphic temperatures in the range 200–250°C for the basaltic sills. Stable isotope compositions of iron-rich chlorites (¹⁸O-5.5; D from-60 to-50) and plagioclases (¹⁸O from +9 to +10) reveal that the source of the fluid was certainly seawater. The ¹⁸O variations within the sills are strongly correlated with the rate of progress of the main metamorphic reaction:clinopyroxene+plagioclase+ilmenite chlorite+albite+epidote+quartz+sphene that produced major element mobility at the scale of the volcanosedimentary sequence. Calculation of elemental fluxes by mass balance combined with oxygen isotopic compositions of basalts shows that the highest water-rock ratios (1) were at sill-sediment boundaries and within pillow lavas at the top of the pile. The volcanosedimentary sequence of Erquy was a net sink for Na and a source for Ca. No Mg uptake could be detected whereas the hydrothermal alteration of the sediments released Fe, Si, and K trapped by the volcanic rocks. The ¹⁸O value of the fluid reacting with sills appears to have shifted no more than +4 after percolation at low temperature through immature sediments (¹⁸O12). The Erquy volcano-sedimentary sequence represents a marine hydrothermal system dominated by low-temperature exchange which allowed a general ¹⁸O-enrichment of the volcanic rocks and a ¹⁸O-depletion of sediments.     

Microbe–mineral interactions: early carbonate precipitation in a hypersaline lake (Eleuthera Island, Bahamas)

Microbialites (benthic microbial carbonate deposits) were discovered in a hypersaline alkaline lake on Eleuthera Island (Bahamas). From the edge towards the centre of the lake, four main zones of precipitation could be distinguished: (1) millimetre‐sized clumps of Mg‐calcite on a thin microbial mat; (2) thicker and continuous carbonate crusts with columnar morphologies; (3) isolated patches of carbonate crust separated by a dark non‐calcified gelatinous mat; and (4) a dark microbial mat without precipitation. In thin section, the precipitate displayed a micropeloidal structure characterized by micritic micropeloids (strong autofluorescence) surrounded by microspar and spar cement (no fluorescence). Observations using scanning electron microscopy (SEM) equipped with a cryotransfer system indicate that micrite nucleation is initiated within a polymer biofilm that embeds microbial communities. These extracellular polymeric substances (EPS) are progressively replaced with high‐Mg calcite. Discontinuous EPS calcification generates a micropeloidal structure of the micrite, possibly resulting from the presence of clusters of coccoid or remnants of filamentous bacteria. At high magnification, the microstructure of the initial precipitate consists of 200–500 nm spheres. No precipitation is observed in or on the sheaths of cyanobacteria, and only a negligible amount of precipitation is directly associated with the well‐organized and active filamentous cyanobacteria (in deeper layers of the mat), indicating that carbonate precipitation is not associated with CO₂ uptake during photosynthesis. Instead, the precipitation occurs at the uppermost layer of the mat, which is composed of EPS, empty filamentous bacteria and coccoids (Gloeocapsa spp.). Two‐dimensional mapping of sulphate reduction shows high activity in close association with the carbonate precipitate at the top of the microbial mat. In combination, these findings suggest that net precipitation of calcium carbonate results from a temporal and spatial decoupling of the various microbial metabolic processes responsible for CaCO₃ precipitation and dissolution. Theoretically, partial degradation of EPS by aerobic heterotrophs or UV fuels sulphate‐reducing activity, which increases alkalinity in microdomains, inducing CaCO₃ precipitation. This degradation could also be responsible for EPS decarboxylation, which eliminates Ca²⁺‐binding capacity of the EPS and releases Ca²⁺ ions that were originally bound by carboxyl groups. At the end of these processes, the EPS biofilm is calcified and exhibits a micritic micropeloidal structure. The EPS‐free precipitate subsequently serves as a substrate for physico‐chemical precipitation of spar cement from the alkaline water of the lake. The micropeloidal structure has an intimate mixture of micrite and microspar comparable to microstructures of some fossil microbialites.     

Aerosol-trace gases interactions and their role in air quality control of Delhi city (India)

Atmospheric dust is considered to be the major cause of poor air quality due to its contribution to high particulate levels, but their interaction with the acidic gases helps in controlling the level of SO₂ and NO₂ through ambient neutralization reactions. In the present study, the interaction of acidic gases such as SO₂ and NO₂ with alkaline dust was investigated during October, 2013–July, 2014 at a site named as Babarpur located at the Trans-Yamuna region of Delhi. The concentration of SO₂ ranged from 10 to 170 μg/m³ with an average of 36 μg/m³ while that of NO₂ ranged from 15 to 54 μg/m³ with an average of 26?±?8 μg/m³. The results were observed to be well within the National Ambient Air Quality Standard (NAAQS) limits prescribed by the Central Pollution Control Board (CPCB). The average concentrations of SO₂ during day and night time were recorded as 31?±?18 and 43?±?53 μg/m³ respectively while the mean concentrations of NO₂ during day and night time were recorded as 26?±?7 and 27?±?12 μg/m³ respectively. A positive correlation between SO₄^2? and NO₃^? was also observed indicating their secondary aerosol formation. In aerosol phase, average concentrations of SO₄^2? during day and night time were 3.9?±?0.3 and 6.5?±?2.3 μg/m³ respectively while that of NO₃^? were 9.5?±?1.5 and 7.3?±?0.5 μg/m³ respectively. Molar ratios of Ca²⁺/SO₄^2?, NH₄⁺/SO₄^2?, and NH₄⁺/NO₃^? were observed as 8, 5, and 1.7 during daytime and 1.5, 0.4, and 0.8 during nighttime respectively. Such molar ratios confirmed high concentrations of sulphate (SO₄)^2? and low concentrations of nitrate (NO₃^?) during night time, thereby indicating different pathway of aerosol formation during day and night time. Surface morphology and elemental composition of aerosol samples showed various oval, globular, and platy shapes where the diameter varied from few nm to ~5 μm depending on their precursors. There were certain shapes like grossularite, irregular aggregate, grape-like, triangular, and flattened which indicate the crustal origin of aerosols and their possible role in SO₂ and NO₂ adsorption.     

Fluid-rock interactions in a geothermal Rotliegend/Permo-Carboniferous reservoir (North German Basin)

Comprehensive data on the chemical composition of reservoir rocks and geothermal brines from the geothermal well doublet Groβ Schönebeck (North German Basin) drilled into a Rotliegend sedimentary and Permo-Carboniferous volcanic rock reservoir were sampled over the past years. They were characterized with respect to their major and minor elemental composition including various isotope ratios. The study considered the impact of drilling and reservoir operations on fluid composition and aimed at determining fluid–rock interactions to gain information on fluid origin and hydraulic pathways.The highly saline fluids (up to 265 g/L TDS) show δ ¹⁸O and δD of water (2.7–5.6 and −3.1–15, respectively) as well as δ ³⁴S of sulfate (3.6–5), and ⁸⁷Sr/⁸⁶Sr ratios (0.715–0.716) that resemble Rotliegend brines from an area located around 200 km in the west (the Altmark). Halogen ratios indicated that brines developed predominantly by evaporation of meteoric water (primary brine) together with halite dissolution brine (secondary brine). Indication for mixing with Zechstein brine or with younger meteoric water was not found.No geochemical distinction was possible between fluids deriving from different rock formations (dacites or sedimentary rocks, respectively). This is due to the evolution of the sediments from the effusive rocks resulting in a similar mineralogical and chemical composition and due to a hydraulic connectivity between the two types of rock. This connection existed probably already before reservoir stimulation as indicated by a set of faults identified in the area that could connect the Rotliegend formation with both, the volcanic rocks and the lower units of the Zechstein. Additional geochemical indication for a hydraulic connectivity is given by (1) the very high heavy metal contents (mainly Cu and Pb) in fluids and scaling that derive from the volcanic rocks and were that were also found in increased amounts up at the Zechstein border (Kupferschiefer formation). (2) The ⁸⁷Sr/⁸⁶Sr isotope ratios of fluid samples correspond to the ratios determined for the sedimentary rocks indicating that initially the fluids developed in the sedimentary rocks and circulated later, when faults structures were created by tectonic events into the volcanic rocks.     

Hydrogen bonding interactions in phase A [Mg7Si2O8(OH)6] at ambient and high pressure

Neutron powder diffraction data of phase A (Mg₇Si₂O₈(OH)₆) were collected at ambient pressure and 3.2?GPa (calculated from the compressibility of phase A) from the deuterated compound, and the structure was refined using the Rietveld method. The derived crystal structure implies that hydrogen atoms occupy two distinct sites in phase A, both forming hydrogen bonds of different lengths with the same oxygen atom. This picture is supported by IR spectra, which exhibit two absorption bands at 3400 and 3513?cm^?1 corresponding to OH stretching vibrations, and proton NMR spectra, which display two peaks with equal intensities and isotropic chemical shifts of 3.7 and 5?ppm. The D-D distance [D(1)-D(2) distance] at ambient pressure was found to be 2.09?±?0.02?Å from the neutron diffraction data and 2.09?±?0.05?Å from the NMR spectra. At 3.2?GPa, there is no statistically significant increase in the O-D interatomic distance while the hydrogen bonding interaction D···O appears to increase for one of the hydrogen sites, D(1), which has the stronger hydrogen bonding interaction compared with the other hydrogen, D(2), at ambient pressure. The O-D bond valences, determined indirectly from the D···O distances were 0.86 and 0.91 at ambient pressure, and 0.83 and 0.90?at 3.2?GPa, for D(1) and D(2), respectively.     

一例和平永川龙（恐龙：兽脚类）肩胛骨骨折

记述了自贡地区的和平永川龙（和平中华盗龙）（Yangchuanosaurus(Sinraptor)hepingensis）ZDM 0024存在一断裂后愈合的肩胛骨,这是中国兽脚类病理学的首次详细记录。该肩胛骨有骨皮质不连续、成角畸形、骨痂形成,符合骨折后愈合的表现,而且从其病理特征看,病理性骨折的可能性很小,直接暴力所致骨折的可能性极大。还分析了同时期动物群中可能存在暴力施加者,拥有尾锤的合川马门溪龙（Mamenchisaurus hochuanensis）可能性最大,这为和平永川龙的骨折提供了一种有趣的解释。     

PG 1316+678: A young pre-cataclysmic binary with weak reflection effects

The PG 1316+678 star is classified as a pre-cataclysmic binary, as is evidenced by its photometric and spectroscopic observations. Its orbital period is determined to be P _orb = 3.3803^d, which coincides with the photometric period. The intensities of the emission HI and HeI lines are shown to vary synchronously with the brightness of the object (Δm _V = 0.065 ^m , Δm _R = 0.08 ^m ). These variations arise as the UV radiation from the DAO white dwarf is reflected from the surface of the cold companion. The parameters of the binary are estimated and the time of its evolution after the common-envelope phase is determined to be t ≈ 240 000 years. Thus, PG 1316+678 is a young pre-cataclysmic NN Ser variable with the smallest known photometric reflection effect.     

Metasomatic interactions between slab-derived melts and depleted mantle: Insights from xenoliths within Monglo adakite (Luzon arc, Philippines)

The Monglo adakite contains mafic and ultramafic xenoliths, which probably originated from the mantle section of an Early Cretaceous supra-subduction zone ophiolitic complex located within the Luzon arc crust. Spinel-bearing dunites are dominant among this xenolith collection and display evidence for three episodes of subduction-related melt percolation. The first one is evidenced by an undeformed clinopyroxene characterized by convex-upwards REE pattern. This clinopyroxene crystallized from a calc-alkaline basaltic magma, likely formed in the Cretaceous supra-subduction setting of the ophiolite. Then, two metasomatic events, evidenced by orthopyroxene-rich and amphibole-rich secondary parageneses, respectively, affected most of the spinel dunites. The opx-rich paragenesis is related to the circulation within the dunitic upper mantle of hydrous slab-derived melts similar to those affecting the mantle peridotite xenoliths from Papua New Guinea and Kamchatka. Finally the amphibole-rich veins are related to the interaction between the studied dunite xenoliths and the host adakite or an adakitic melt similar to it.