Formation Of Deposits Research Articles

Origin and microbial degradation of thermogenic hydrocarbons within the sandy gas hydrate reservoirs in the Qiongdongnan Basin, northern South China Sea

Large-scale natural gas hydrate accumulations (generally over one billion cubic meters of natural gas) in coarse-grained marine sediments are the most valuable types for commercial exploration and exploitation. The formation of such a gas hydrate deposit generally requires a sufficient natural gas supply such as deeply buried thermogenic gas source. However, the worldwide discovered thermogenic gas hydrate deposits are rare, leaving relatively a poor understanding of their formation and evolution. Based on the geochemical and microbial analyses of eleven hydrate-related gas and five sediment samples from the thermogenic gas hydrate deposits in the Qiongdongnan Basin in northern South China Sea, we systematically investigated the origin and evolution of thermogenic hydrocarbons within sandy gas hydrate reservoirs. Results show that natural gas within high saturated gas hydrate-filled sandy sediments is predominately of thermogenic (the proportion is 57.1–70.5%), characterized by “dry gas” (99.38–99.7% C1, 0.26–0.47% C2 and <0.5% C3+), relatively lower C1/(C2+C3) ratio (187–376), and heavier δ13C–C1 values (−55.0 to −31.3‰). In addition, typical biomarkers (including the alkanes, tricyclic terpanes, hopanes and steranes) generated from mature source rocks were detected in the hydrate-filled fine sand reservoir, as well as the biomarker indicators (including the unresolved complex mixtures (UCMs) hump and the 25-norhopane homologous series) for severe hydrocarbon biodegradation. Furthermore, large amounts of hydrocarbon degrading bacteria (50.5% of bacteria) and methanogenic archaea (34.3% of archaea) were detected within hydrate-filled sandy sediment. Our results indicated that the deeply buried thermogenic source can indeed provide sufficient gas supply for the formation of a large-scale gas hydrate deposit, but thermogenic liquid hydrocarbons within gas hydrate reservoirs are very susceptible to be degraded and consumed by hydrocarbon degrading bacteria. In addition, we also found that the clay components of argillaceous gas hydrate reservoirs can adsorb and store large amounts of in situ immature organic matter, which can significantly obscure or cover up the original geochemical signatures of thermogenic hydrocarbons therein. These findings suggest that the relative contribution of deeply buried thermogenic source for gas hydrate accumulation worldwide may be underestimated, because we have previously ignored the fact that thermogenic hydrocarbons within gas hydrate reservoirs would be significantly consumed by hydrocarbon degrading microbes or diluted by in situ immature sedimentary organic matter. Our findings are highly significant for the evaluation and exploration of thermogenic gas hydrate accumulations worldwide.

Transparent and mechanically durable silicone/ZrO2 sol hybrid coating with enhanced antifouling properties

Achieving a delicate equilibrium between the mechanical and antifouling attributes of silicone-based coatings remains a formidable task. This research unveiled a novel approach to crafting a hybrid antifouling coating through the amalgamation of an amphiphilic telomer, Zirconia (ZrO2) sol, triethoxyoctylsilane (KH832) and tetraethyl orthosilicate (TEOS) using an uncomplicated sol–gel technique. The amphiphilic telomer, derived from a synthesized antibacterial acrylamide-benzothiazole small molecule, hydrophobic silanes/fluorosilanes, and hydrophilic monomers, was intricately tethered with the ZrO2 sol, synthesized through the hydrolysis of n-propyl zirconate. The resultant coating achieved exceptional transparency (>98 % transmittance), attributed to the covalent linkage between the robust zirconia structure and the pliable, long-chain telomer. This unique bonding imparted the coating with remarkable characteristics, including high hardness (4–6H), flexibility (∼5 mm bending diameter), wear resistance, and strong adhesion (∼2.89 MPa) to the substrate. Furthermore, the self-enrichment property of the non-leaching amphiphilic telomer within the hybrid matrix contributed to the coating’s outstanding self-cleaning capabilities, as well as its remarkable ability to resist fouling, including bacterial adhesion, protein attachment, diatom deposition, and biofilm formation. Overall, our research systematically explored the influence of composition and structure on both mechanical properties and antifouling performance. Ultimately, we sought to advance the development of a high-performance organic–inorganic hybrid antifouling coating poised to address the diverse requirements of applications spanning optical instruments, foldable displays, marine facilities, and various other fields.

Analysis of the influence of local electrodeposition conditions on the accuracy of electrochemical 3D-printing

Problem. Additive manufacturing of metal parts by local electrodeposition is a new promising area with several unique features. The use of electrolysis makes it possible to manufacture metal parts at room temperature with high accuracy and low energy consumption. The accuracy and speed of electrochemical 3D printing are inversely related, and therefore it is important to find optimal electrodeposition conditions at maximum speed without degrading accuracy. The aim of the study. The purpose of this work was to analyse the influence of electrodeposition parameters (electrode distance, electrical conductivity and electrolyte polarization) on the accuracy of metal deposit formation in a computer model and to conduct experimental verification of optimal conditions for electroforming a real object from copper sulphate electrolyte. Methodology of implementation. To achieve the goals of the study, computer simulation of the electrochemical deposition process in the COMSOL Multiphysics software and electrochemical measurements of the characteristics of copper sulphate electrolytes were used. Research results. Computer simulation established optimal conditions: the distance between the edge of the capillary and the surface on which deposition occurs is not more than 0.5 mm, the electrolyte in which the inverse slope of the cathode polarization curve is not lower than 2000 mA/(V×cm2) and the electrical conductivity is not higher than 0.02 S/сm. The influence of the electrolyte composition on the inverse polarization of the cathode process and its electrical conductivity was investigated. The optimal composition of the electrolyte was selected, containing 200 g/L CuSO4, 60 g/L H2SO4, 0.2 g/L KCl and RUBIN T-200 additive. In the selected electrolyte, the value of the inverse slope of the cathode polarization curve is 2120 mA/(V×cm2). Verification of the process of local electrodeposition in the selected electrolyte during the electroformation of a cylindrical object with a diameter of 4 mm and a height of 100 μm was carried out. It was determined that no more than 5 % of metal was deposited outside the capillary of the working electrode. Conclusions. The results of the work can be used to create an electrochemical 3D printing system. Further research should be aimed at approbation of the obtained parameters of local electrodeposition in an installation that simulates the operation of a 3D printer and establish the accuracy and speed of printing of a three-dimensional object. Key words: additive manufacturing, electrical conductivity, electrolyte composition, polarization, local electrodeposition.

The large granitic pegmatite Li deposits formed at final collision of a three micro-continent amalgamation in the Central Altun Tagh, Northwest China

Micro-continent collision and amalgamation play pivotal roles in continental convergence and contribute significantly to continental crustal growth. However, the understanding of multiple micro-continent amalgamation processes, particularly their influence on the formation of large Li-Be deposits, remains limited. The Altun orogenic system, resulting from the collision and amalgamation of three micro-continents in the Proto-Tethys Ocean, has recently revealed numerous granitic pegmatite-type Li-Be deposits, presenting an ideal opportunity to investigate the mineralization. Our research focused on two large granitic pegmatite Li deposits, South Washixia and Tamuqie in the Central Altun Tagh, Northwest China. Our findings suggest: 1) The structural and photomicrograph characteristics observed in both the Tamuqie and South Washixia granitic pegmatite Li deposits, indicate that the pegmatites emplaced in shear zone within a contractional deformation zone. 2) The age of the large granitic pegmatite Li deposit in South Washixia between 447 ∼ 445 Ma, while the Tamuqie Li pegmatites formed at 448 Ma with Li-barren pegmatites formed at around 418 Ma. It is suggested that the large granitic pegmatite Li deposit in the Central Altun Block, encompassing South Washixia and Tamuqie granitic pegmatite Li deposits, originated during the final collision event of three micro-continent blocks (Qaidam, Altun-Qilian, and Dunhuang-Alex). We suggest that during the final collision and amalgamation event of multiple micro-continents triggering intense compression and thickening of the crust, and the thickened lower crust may undergo shear-driven dehydration melting of biotite in granulite facies to produce large-volume granitic magmas. These magmas crystallize and differentiate into lithium-rich pegmatitic magmas along shear zones, forming large lithium pegmatite deposits. Our research presents a novel mechanism for the formation of granitic pegmatite Li deposits, which emphasizes the role of shear-driven dehydration melting during the final collision and amalgamation events of three micro-continents.

Numerical modeling of the mineralizing processes within the Shaxi porphyry-type Cu-Au deposit, Eastern China: Influence and restriction from physical and chemical characteristics of host rocks

The Shaxi porphyry-type Cu-Au deposit is located in the northwestern outer margin of the Luzong volcanic basin, which is situated in the Middle-Lower Yangtze River Metallogenic Belt (MLYRMB), Eastern China. It is a large porphyry-type Cu-Au deposit with confirmed copper resources exceeding 1 Mt and gold resources exceeding 40 tons. Previous studies have extensively investigated the genesis, controlling structures, geochemical characteristics, fluid evolution, alteration zone, and ages of mineralization and host rocks in this deposit. However, research on the influence of the physical and chemical properties of the host rocks on the mineralizing processes has not been explored in detail. This study employs the finite element method to apply numerical modeling of multiple physical and chemical fields, interlinking heat transfer, fluid flow, material migration, mineralization reaction, and their coupling with porosity and permeability of rock, to investigation of the influence of different porosities, permeabilities, and chemical properties of the host rocks on the mineralizing processes in the Shaxi deposit. The results show that the porosity and permeability of the host rocks play a significant role in the mineralization of porphyry-type systems. The different porosity and permeability of the intrusions and strata control the depth, the mineralization intensity, the morphology of the ore bodies, and the spatial location of the mineralization center. The chemical properties of the strata significantly restrict the mineralization intensity and horizontal spatial rather than affecting the depth of mineralization. Furthermore, the formation of skarn-type deposits may require a longer period of time than that of porphyry-type deposits under the same mineralization conditions and ore grade. This paper also indicates that the numerical modeling method employed in this study can be used to predict the mineralization depth and spatial location of deep concealed porphyry-type deposits, aiding research in deep-seated mineral exploration.

Electrochemical Characterization of Electrodeposited Copper in Amine CO2 Capture Media.

This study explores the stability of electrodeposited copper catalysts utilized in electrochemical CO2 reduction (ECR) across various amine media. The focus is on understanding the influence of different amine types, corrosion ramifications, and the efficacy of pulse ECR methodologies. Employing a suite of electrochemical techniques including potentiodynamic polarization, linear resistance polarization, cyclic voltammetry, and chronopotentiometry, the investigation reveals useful insights. The findings show that among the tested amines, CO2-rich monoethanolamine (MEA) exhibits the highest corrosion rate. However, in most cases, the rates remain within tolerable limits for ECR operations. Primary amines, notably monoethanolamine (MEA), show enhanced compatibility with ECR processes, attributable to their resistance against carbonate salt precipitation and sustained stability over extended durations. Conversely, tertiary amines such as methyldiethanolamine (MDEA) present challenges due to the formation of carbonate salts during ECR, impeding their effective utilization. This study highlights the effectiveness of pulse ECR strategies in stabilizing ECR. A noticeable shift in cathodic potential and reduced deposit formation on the catalyst surface through periodic oxidation underscores the efficacy of such strategies. These findings offer insights for optimizing ECR in amine media, thereby providing promising pathways for advancements in CO2 emission reduction technologies.

Assessing Key Issues Contributing to the Degradation of NCM‐622 || Cu Cells: Competition Between Transition Metal Dissolution and “Dead Li” Formation

AbstractCombining LiNixCoyMn1−x−yO2 (NCM) as cathode with bare Cu as anode will potentially lead to next‐generation batteries that are smaller, lighter, and can run for longer periods on a single charge. However, maintaining high performance and a long lifespan of NCM || Cu cells is challenging as it can be affected by various factors from both the cathode and the anode. From the cathode, it is well‐known that transition metal (TM) dissolution accelerates cell degradation. From the anode, one of the main challenges is the formation of high surface area Li deposits which later transform into “inactive Li” or “dead Li”. In this study, a comprehensive assessment regarding these competing factors (i.e., TM deposits and “dead Li”) is discussed. Accelerated TM dissolution is accomplished by introducing TM‐containing additives into the electrolyte. The effects of these competing factors and their degradation mechanism are studied quantitatively and qualitatively through inductively coupled plasma, i.e., optical emission spectroscopy and mass spectrometry. The “dead Li” influence is analyzed quantitatively using gas chromatography. The results demonstrate the obvious deleterious impact of dissolved TM ions on cell performance. At the same time, “dead Li” has also become a notable factor for a sudden capacity drop.

Geochronology and geochemistry of the Banjiaoyuan tin deposit, southern Hunan Province and its geological implications

Situated in the central part of the Southern Hunan segment of the Nanling Metallogenic Belt, the Banjiaoyuan tin deposit represents a significant Indosinian quartz vein type tin deposit. Based on field geological surveys and petrographic observations, the mineralization in the area can be divided into three stages: (I) early greisen stage, (II) cassiterite-quartz vein stage, and (III) late barren quartz vein stage. The dating results show that the 40Ar-39Ar plateau age of muscovite in stage I is 215.51 ± 0.87 Ma, and the Rb-Sr isochronous age of quartz mineral in stage II is 214.2 ± 3.1 Ma (MSWD = 1.3), both of which are coincide with the cassiterite U-Pb lower intercept age (215.7 ± 1.3 Ma, MSWD = 1.2), confirming the existence of metallogenic events in this region during the late Indosinian. The δD and δ18O of quartz in stage II range from −66.2 to −80.2 ‰, and 3.71 to 6.17 ‰, respectively, indicating that the ore-forming fluid is mainly derived from a mixture of magmatic-hydrothermal fluids and a small amount of meteoric water. We applied LA-ICP-MS chemical mapping and trace elements analysis to cassiterites, found that they underwent a transition from oxidation to reduction during precipitation when the fluids tend to be more volatile-rich and highly fractionated. The formation of the Banjiaoyuan tin deposit is closely related to the late Indosinian magmatic activity in the Yangmingshan region. Besides, the deep and peripheral parts of the mining area also have the potential for large-scale vein-type and greisen-type W-Sn mineralization.

Genesis of the Hujiazhuang apatite-rich carbonatite complex in North China and its implication for the REE fertility of the carbonatite system

Apatite is a common REE-compatible mineral in carbonatites, so its formation can affect the REE ore-forming potential of carbonatite systems. In nature, there are numerous apatite-rich carbonatite complexes, but the petrogenesis of these complexes has long been debated. To resolve this controversy, this study conducts elemental and isotopic analyses on the Mesozoic (∼120 Ma) Hujiazhuang carbonatite complex in North China. The Hujiazhuang complex contains magnetite-calcite-apatite carbonatites and calcite carbonatites. Calcite grains from these two rock phases exhibit identical initial 87Sr/86Sr ratios (0.71027–0.71038), indicating a common parental magma derived from a metasomatized lithosphere mantle. Then, from magnetite-calcite-apatite carbonatites to calcite carbonatites, the Mg, Fe, and Mn contents of calcite continuously increase while the Sr and REE contents decrease, consistent with elemental variations of calcite during fractional crystallization of carbonatitic magma. Therefore, these two lithologies are proposed to be formed through fractional crystallization of a common magma. Notably, the Hujiazhuang carbonatite complex was derived from a metasomatized lithosphere mantle and experienced intensive fractionation, which potentially facilitate the formation of REE deposits. However, this complex cannot meet REE's economic standard. The early-stage magnetite-calcite-apatite carbonatites have high REE contents (3,675–11,075 ppm), and a positive correlation can be observed between REE and P contents in this lithology. It indicates that early, extensive crystallization of apatite led to REE dispersion, largely hindering REE enrichment in later stages. In general, this study provides important insights into the genesis of the apatite-rich carbonatite complex and advances our understanding of the REE dispersion or enrichment behaviors in carbonatite system.

Relationships between Osteopontin, Osteoprotegerin, and Other Extracellular Matrix Proteins in Calcifying Arteries.

Osteopontin (OPN) and osteoprotegerin (OPG) are glycoproteins that participate in the regulation of tissue biomineralization. The aim of the project is to verify the hypothesis that the content of OPN and OPG in the aorta walls increases with the development of atherosclerosis and that these proteins are quantitatively related to the main proteins in the extracellular arteries matrix. Quantitative and qualitative analyses of the OPN and OPG content in 101 aorta sections have been conducted. Additionally, an enzyme-linked immunosorbent assay (ELISA) test has been performed to determine the collagen types I-IV and elastin content in the tissues. Correlations between the biochemical data and patients' age/sex, atherosclerosis stages, and calcification occurrences in the tissue have been established. We are the first to report correlations between OPN or OPG and various types of collagen and elastin content (OPG/type I collagen correlation: r = 0.37, p = 0.004; OPG/type II collagen: r = 0.34, p = 0.007; OPG/type III collagen: r = 0.39, p = 0.002, OPG/type IV collagen: r = 0.27, p = 0.03; OPG/elastin: r = 0.42, p = 0.001; OPN/collagen type I: r = 0.34, p = 0.007; OPN/collagen type II: r = 0.52, p = 0.000; OPN/elastin: r = 0.61, p = 0.001). OPN overexpression accompanies calcium deposit (CA) formation with the protein localized in the calcium deposit, whereas OPG is located outside the CA. Although OPN and OPG seem to play a similar function (inhibiting calcification), these glycoproteins have different tissue localizations and independent expression regulation. The independent expression regulation presumably depends on the factors responsible for stimulating the synthesis of collagens and elastin.

Recent advances in separator design for lithium metal batteries without dendrite formation: Implications for electric vehicles

Electric vehicle (EV) technology addresses the challenge of reducing carbon and greenhouse gas emissions. The power battery, which serves as the energy source for EVs, directly impacts their driving range, maximum speed, and service life. Considering the high energy density requirements for future EVs, lithium metal anodes possess several advantages such as high theoretical capacity, high energy and power density, and low electrochemical reduction potential which enable them to be a promising material for next-generation batteries. However, lithium metal anodes suffer from short cycle life and safety concerns due to the formation of dendritic and moss-like metal deposits that impede battery performance and reliability. This review will feature the recent advancement of functional separators to tackle these challenges. Firstly, this review presents a comprehensive review of the growth mechanism of lithium dendrites and delineates the underlying processes leading to battery failure. This aims to deepen understanding, which serves as a fundamental basis for classifying separators. Then, according to the growth of lithium dendrites and the failure process of lithium metal batteries, namely lithium-ion nucleation, growth of lithium dendrites, penetration of lithium dendrites into the separator, thermal runaway and even failure of the battery, four types of functional separators for different stages are proposed. The functions of these types of separators are to prevent the nucleation of lithium ions and regulate the uniform deposition of lithium ions, detect and eliminate dendrites, increase the mechanical strength of the separator and enhance the thermal stability and flame-retardancy of the separators, respectively. Finally, the recent advances of the above strategies are reviewed and discussed, existing critical problems are identified, and the future perspective of functional separators for the safety of lithium metal batteries is also discussed.

Redox control of the partitioning of platinum and palladium into magmatic sulfide liquids

The partitioning behavior of platinum group elements in magmas is critical for their use as tracers of planetary accretion and in understanding magmatic sulfide deposits. Here we use laboratory experiments to determine sulfide liquid–silicate melt partition coefficients for platinum and palladium at 1.5 GPa, 1400 °C, and oxygen fugacity 1.5–2 log units above the fayalite–magnetite–quartz buffer. We find that the partitioning coefficients of these elements are 2.3 × 105 to 1.1 × 106 and are independent of the platinum and palladium concentration in the system. Combined with previous data obtained at oxygen fugacity below the fayalite–magnetite–quartz buffer, this indicates redox-controlled partitioning behavior whereby at oxidizing conditions platinum- and palladium-enrichments are achieved through their dissolution in sulfide liquids, while at reducing conditions the entrapment of platinum- and palladium-rich clusters in sulfide liquids is more critical. This redox-controlled partitioning behavior should be considered when studying crust–mantle differentiation and the formation of magmatic sulfide deposits.

Graphical, statistical and index-based techniques integrated for identifying the hydrochemical fingerprints and groundwater quality of In Salah, Algerian Sahara.

Groundwater, a predominant reservoir of freshwater, plays a critical role in providing a sustainable potable water and water for agricultural and industry uses in the In Salah desert region of Algeria. This research collected 82 underground water samples from Albian aquifers to assess water quality and identify hydrogeochemical processes influencing mineralization. To achieve this objective, various methods were employed to evaluate water quality based on its intended uses. The drinking water quality index utilized revealed the water potability status, while the indicators of irrigation potability were employed to evaluate its quality for agricultural purposes. Additionally, an assessment of groundwater susceptibility to corrosion and scaling in an industrial context was conducted using several indices, e.g., Langelier index, Larson-Skold index, Ryznar index, chloride-sulfate mass ratio, Puckorius index, aggressiveness index, and the Revelle index. The findings of this study revealed thatthe groundwater quality for consumption fell into four categories: good (2.44%), fair (29.27%), poor (65.85%), and non-potable (2.44%). Concerning agricultural irrigation, the indexical results indicated that 15.85% of the waters exhibited adequate quality, while 84.15% were questionable for irrigation. Calculations based on various corrosion and scaling evaluation indices showed that most wells were prone to corrosion, with a tendency for calcium bicarbonate deposit formation. Furthermore, the hydrochemical study identified three water types: Na-Cl (53.66%), Ca-Mg-Cl (37.80%), and Ca-Cl (8.54%) waters. Analyses of correlation matrices, R-type clustering, factor loadings, Gibbs diagrams, scatterplots, and chloro-alkaline indices highlighted that the chemistry of the Albian groundwater is fundamentally impacted by a number of processes such as silicate weathering, evaporite dissolution, ionic exchange, and anthropogenic inputs, that played impactful role in the aquifer's water chemistry.

Development of a method for monitoring the formation of organic deposits on the inner surface of the oilwell tubing

ABSTRACT Intensive formation of organic deposits in the tubing of an oil production well is one of the most serious complications in oil production. An important task is to correctly assess the effectiveness of the methods used to combat the deposits in question. Field diagnostics of the condition of the inner surface of the production tubing is carried out by evaluating indirect parameters that do not allow evaluating the distribution of deposits along the production tubing. With the aim of solving these problems the authors of this work have developed a method for monitoring the formation of deposits on the inner surface of the tubing on the basis of the ‘thermal analogy’ mechanism. The applicability of the technology was evaluated at the Wax Flow Loop laboratory stand. The developed mathematical model for calculating the dynamics of sediment formation based on the temperature parameters of the flow significantly correlates with the data obtained using the basic barometric method. The use of this technology will make it possible to increase the efficiency of oilfield equipment, reduce the accident rate of production, more correctly select methods for combating wax deposition and evaluate their effectiveness.

Enrichment and fractionation of rare earth elements (REEs) in ion-adsorption-type REE deposits: Constraints of an iron (hydr)oxide–clay mineral composite

Abstract Ion-adsorption-type rare earth element (REE) deposits are the source of more than 90% of global heavy REEs (HREEs). Thus, understanding the ore genesis of REEs, particularly the distribution characteristics and enrichment mechanisms of HREEs, is vital for efficient exploration and mining of ion-adsorption-type REE deposits worldwide. The characteristics and petrogenesis of bedrock, and the aqueous mobility of REEs, are known to be important factors controlling REE accumulation and fractionation in the weathering crust of REE deposits. However, the effect of REE adsorption on secondary minerals, which is a crucial step in deposit formation, remains poorly understood. This problem was addressed by the study described herein, which involved a systematic analysis of the complete weathering profile (78 m) of the Renju ion-adsorption-type REE deposit in South China and a simulated adsorption experiment. Clay minerals and iron (Fe) (hydr)oxides are the dominant REE adsorbents in the weathering crust and most are micro-to-nanosized particles. Thus, the fine particle fraction (&amp;lt; 2 μm) was separated from field samples, to better disclose their effects on the concentration and redistribution of REEs. Phase compositions and morphologies were characterized by X-ray diffraction, Mössbauer spectrometry, and scanning/transmission electron microscopy (SEM/TEM), which revealed that various clay minerals and Fe (hydr)oxides form composites along the profile of the deposit. Composites of ferrihydrite–kaolinite, goethite–kaolinite/halloysite, and hematite–kaolinite/halloysite were found to be distributed in the semi-weathered, completely weathered, and topsoil layers, respectively, with different sizes and shapes. The concentrations and partition patterns of REEs in different occurrence states were distinguished after sequential extraction. Ion-exchangeable-REEs were the major state and enriched in the upper completely weathered layer. These species were found to be adsorbed onto kaolinite and halloysite via electrostatic attraction, without obvious fractionation. Fe (hydr)oxides were determined to comprise ca. 20% of REEs at most depths and over 50% of REEs in the topsoil and semi-weathered layer. It was found that Fe (hydr)oxides scavenge REEs through complexation and oxidation, resulting in HREE enrichment and a positive cerium (Ce) anomaly, respectively. In addition, compared with crystalline Fe (hydr)oxides, amorphous Fe (hydr)oxides immobilize more REEs but exhibit weaker preferential adsorption of HREEs. The above-described findings are consistent with the results of simulated experiments for REE adsorption onto a clay mineral–Fe (hydr)oxide composite (Bt-60), which was obtained from hydrothermal processing of biotite. Furthermore, the distributions and stabilities of LREEs and HREEs were distinguished by TEM–energy–dispersive spectroscopy (EDS) of Bt-60 before and after REE extraction by ammonium sulfate. The phase transformation pathways of clay minerals and Fe (hydr)oxides, and their different enrichment and fractionation characteristics in REEs, were also discussed in terms of the structure and surface properties of minerals, adsorption mechanisms, and variations in chemical properties across the REE group. The results shed new light on how clay minerals and Fe (hydr)oxides affect the enrichment and fractionation of REEs in ion-adsorption-type deposits.

Design and Mechanism Study of High-Safety and Long-Life Electrolyte for High-Energy-Density Lithium-Ion Batteries.

Although nonflammable electrolytes are beneficial for battery safety, they often adversely affect the electrochemical performance of lithium-ion batteries due to their poor compatibility with electrodes. Herein, we design a nonflammable electrolyte consisting of cyclic carbonate and 2,2-difluoroethyl acetate (DFEA) solvents paired with several surface-film-forming additives, significantly improving the safety and cycling performance of NMC811||SiOx/graphite pouch cells. The DFEA solvent exhibits not only good flame retardancy but also lower lowest unoccupied molecular orbital (LUMO) energy, promoting the formation of a robust inorganic-rich and gradient-architecture hybrid interface between the SiOx/graphite anode and electrolyte. The double insurance of good flame retardancy of the DFEA solvent and decreased exothermic effects of both bulk electrolyte and DFEA-derived solid electrolyte interphase (SEI) can ensure the high safety of the pouch cell. Moreover, the highly robust SEI can prevent the excessive reduction decomposition of the electrolyte and alleviate the structural decay of the anode, which can restrain the formation of lithium deposition on the anode surface and further suppress the structural decay of NMC materials. This contributes to the unprecedented cycling performance of the NMC811||SiOx/graphite pouch cells with a capacity retention of 80% after 1000 cycles at a 0.33C rate.

Petrogenesis and REE mineralogical characteristics of Shitouping granites in southern Jiangxi Province: Implication for HREE mineralization in South China

The enrichment of heavy rare earth elements (HREE) in the granitic host-rocks is crucial for generating ion-adsorption HREE deposits in South China. The Shitouping pluton, located in the southern part of Jiangxi Province, South China, develops large-scale HREE deposits in its weathering profile identified by recent geological surveys. These granites can be divided into medium to coarse-grained biotite monzogranite (MGBG), medium to coarse-grained syenogranite (MGSG) and fine-grained alkali feldspar granite (FGAG) based on field observations and mineral assemblages. New geochronologic results show that this composite pluton intruded during the Early Cretaceous (ca. 140 Ma). Three granitic units displaying comparable whole-rock Nd [εNd(t) = −4.5 to −3.4] and zircon Hf compositions [εHf(t) = −4.4 to +1.2], combined with mineral association, hydrothermally altered zircon and whole-rock geochemistry, indicate they were derived from partial melting of hybridized crustal source, followed by intense fractional crystallization and fluid metasomatism in the highly evolved granitic system. The MGSG and FGAG have higher Rb, Nb, HREE contents and Rb/Sr ratios, as well as lower Nb/Ta, K/Rb ratios in comparison with the MGBG, implying they are more evolved units. The overlapping magmatic zircon trace element compositions between MGBG and MGSG, coupled with the subvertical contact boundary between the FGAG and the MGBG, suggest that the generation of Shitouping pluton should be attributed to the periodic magma replenishment, remobilization, and differentiation process in the long-lived magmatic system rather than simple fractional crystallization from a single parental magma. Hydrothermally altered zircon with elevated concentration of HREE and the paragenetic relationship between LREE-phosphate and HREE minerals in the MGSG suggest that the fluid metasomatism promotes the migration and accumulation of HREE. This is consistent with the high HREE concentration recorded in the MGSG, which contains abundant HREE minerals associated with fluorites. Thus, this study highlights that magma differentiation and fluid metasomatism during the late magmatic stage could achieve the relatively high HREE contents in granites to favor the formation of ion-adsorption HREE deposits.

Pharmacodynamic study: Astragaloside IV/chitosan/polylactic acid composite electrospinning scaffold for wound healing in diabetic rats

The wound dressing plays an important role in wound repair as a medical textile that temporarily replaces the skin. However, ordinary wound dressings can only cover wounds and supply a protecting function for wounds, cannot meet some special requirements of chronic wounds, especially diabetic wounds. To overcome these drawbacks, in this study, a novel AS/CS/PLA nanofiber functional dressing was developed to promote diabetic wound healing by electrostatic spinning technology. The pharmacodynamics of AS/CS/PLA nanofiber functional dressings were evaluated. In in vitro pharmacodynamic experiment, the effect of the dressing on cell proliferation was detected by MTT assay. Cell adhesion to the dressing was observed by scanning electron microscopy (SEM), and the cell migration ability promoted by the dressing was evaluated by an in vitro cell scratch test. In in vivo pharmacodynamic experiment, we established a skin wound model in diabetic rats. On the 7th and 15th days, we collected tissue samples from both the surrounding area and the wound area. The expressions of CD31 and TGF-β in wound tissue were detected by H&E and Masson three-color staining, respectively. The results showed that the AS/CS/PLA nanofiber functional dressing could promote cell proliferation, adhesion, and migration. It also increased collagen deposition and granulation tissue formation at wound. Moreover, it promoted the expression of CD31 and TGF-β factors at early stage, thereby accelerating wound healing. Our results indicated that the AS/CS/PLA nanofiber functional dressing have a potential as a treatment material to accelerate diabetic wound healing.

Fat, Oil, and Grease Sewer Waste Management System: A Modeling Platform for Simulating the Formation of FOG Deposits in Sewer Networks

Fat, Oil, and Grease Sewer Waste Management System: A Modeling Platform for Simulating the Formation of FOG Deposits in Sewer Networks

Fluid Migration Regimes during the Formation of the Unconformity-Related Uranium Deposits of the Alligator Rivers Uranium Field, Australia

Fluid Migration Regimes during the Formation of the Unconformity-Related Uranium Deposits of the Alligator Rivers Uranium Field, Australia