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In the last decade, several studies have reported enrichments of the heavy isotopes of moderately volatile elements in lunar mare basalts. However, the mechanisms controlling the isotope fractionation are still debated and may differ for elements with variable geochemical behaviour. Here, we present a new comprehensive dataset of mass-dependent copper isotope compositions (delta 65Cu) of 30 mare basalts sampled during the Apollo missions. The new delta 65Cu data range from +0.14 %o to +1.28 %o (with the exception of two samples at 0.01 %o and -1.42 %o), significantly heavier than chondrites and the bulk silicate Earth. A comparison with mass fractions of major and trace elements and thermodynamic constraints reveals that Cu isotopic variations within different mare basalt suites are mostly unrelated to fractional crystallisation of silicates or oxides and late-stage magmatic degassing. Instead, we propose that the delta 65Cu average of each suite is representative of the composition of its respective mantle source. The observed differences across geographically and temporally distinct mare basalt suites, suggest that this variation relates to large-scale processes that formed isotopically distinct mantle sources. Based on a Cu isotope fractionation model during metal melt saturation in crystal mush zones of the lunar magma ocean, we propose that distinct delta 65Cu compositions and Cu abundances of mare basalt mantle sources reflect local metal melt-silicate melt equilibration and trapping of metal in mantle cumulates during lunar magma ocean solidification. Differences in delta 65Cu and mass fractions and ratios of siderophile elements between low- and high-Ti mare basalt sources reflect the evolving compositions of both metal and silicate melt during the late cooling stages of the lunar magma ocean.

期刊论文 2025-08-01 DOI: 10.1016/j.gca.2025.06.006 ISSN: 0016-7037

We present a high-resolution geologic map of the Rubin crater region, located on Mons Amundsen, which has been identified as a promising site for future lunar exploration (AOI E in Wueller et al., 2024). We developed a design reference mission (DRM) to highlight the region's potential for addressing key lunar science goals, particularly those related to the early lunar bombardment history, lunar crustal rocks, volatiles, impact processes at multiple scales, and regolith properties, as outlined by the National Research Council (2007). The Rubin crater, which formed about 1.58 billion years ago during the Eratosthenian period, excavated material from depths of up to 320 m, potentially reaching the underlying South Pole-Aitken (SPA) massif, Mons Amundsen. This makes the crater's ejecta material, along with the Amundsen ejecta covering the massif, prime targets for sampling SPA-derived materials that can expand our understanding of early Solar System dynamics and the lunar cratering chronology. Additionally, the region hosts several permanently shadowed regions (PSRs), ideal for studying potential lunar volatiles and the processes affecting their distribution. The DRM proposes nine traverse options for exploration via walking EVAs, the Lunar Roving Vehicle (LRV), and LRV-assisted EVAs, with traverse lengths ranging from 3.6 km to 18.2 km. Each traverse is designed to sample diverse geologic units and address multiple scientific objectives. Given its scientific potential and favorable exploration conditions, the Rubin crater region is an ideal location for testing south polar landing operations, potentially paving the way for more complex missions, such as a Shackleton crater landing. (c) 2025 The Author(s). Published by Elsevier B.V. on behalf of COSPAR. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/).

期刊论文 2025-07-15 DOI: 10.1016/j.asr.2025.05.061 ISSN: 0273-1177

This work aims to isolate and screen the fungicidal endophytic bacterial strains for biocontrol efficacy against Phytophthora palmivora, a soil-borne pathogenic fungus that kills durian trees worldwide. Among more than 100 isolates, 6 strains were screened as potential fungicidal strains with inhibitory efficiency of 67.4-79.8%. Based on 16S rRNA gene sequencing and phylogenetic analysis, these strains were identified as Bacillus amyloliquefaciens EB.CK9, Bacillus methylotrophicus EB.EH34, Bacillus amyloliquefaciens EB.EH18, Bacillus siamensis EB.KN10, Bacillus velezensis EB.KN15 and Paenibacillus polymyxa EB.KN35. In greenhouse tests, the two strains P. polymyxa EB.KN35 and B. velezensis EB.KN15 significantly reduced the damage to diseased roots by P. palmivora (33.3 and 35.6%, respectively), increased the rate of survival of durian trees (only 20.8 and 22.9% plant death, respectively), and showed a positive effect on promoting durian plant growth. Notably, the potential fungicidal effect of last two strains against P. palmivora was recorded for the first time in this work. HPLC analysis showed that these strains can secret several plant growth-promoting compounds, including gibberellic acid (GA3), indole-3-acetic acid (IAA), kinetin, and zeatin. Of these, GA3 and zeatin were produced with a significant amount by both strains. The volatiles bio-synthesized by these isolates were also identified using GC-MS analysis, and some major volatiles were found as fungicidal agents. This study suggested that P. polymyxa EB.KN35 and B. velezensis EB.KN15 may be potential biocontrol candidates for durian P. palmivora and bio-fertilizers for the sustainable production of durian crops.

期刊论文 2025-06-15 DOI: 10.1134/S0003683824607650 ISSN: 0003-6838

The extent of moderately volatile elements (MVE) depletion and its effects on the Moon's evolutionary history remain contentious, partly due to unintentionally biased sampling by the Apollo missions from the Procellarum KREEP Terrane. In this study, we analyzed the Zn and K isotope compositions of a series of lunar basaltic meteorites, which vary in Th content and are likely to represent a broader sampling range than previous studies, including samples from the far side of the Moon. Our findings indicate remarkably consistent Zn and K isotope compositions across all lunar basalt types, despite significant variations in Th content. This consistency suggests a relatively homogeneous isotopic composition of volatile elements within the Moon, unaffected by subsequent impact events that formed major basins. Our results suggest that the estimates of MVE abundance and isotopic compositions from the Apollo returned samples are likely representative of the bulk Moon, supporting a globally volatile-depleted lunar interior.

期刊论文 2025-06-03 DOI: 10.1073/pnas.2422726122 ISSN: 0027-8424

The abundances and isotopic signatures of volatile elements provide critical information for understanding the delivery of water and other essential life-giving compounds to planets. It has been demonstrated that the Moon is depleted in moderately volatile elements (MVE), such as Zn, Cl, S, K and Rb, relative to the Earth. The isotopic compositions of these MVE in lunar rocks suggest loss of volatile elements during the formation of the Moon, as well as their modification during later differentiation and impact processes. Due to its moderately volatile and strongly chalcophile behaviour, copper (Cu) provides a distinct record of planetary accretion and differentiation processes relative to Cl, Rb, Zn or K. Here we present Cu isotopic compositions of Apollo 11, 12, 14 and 15 mare basalts and lunar basaltic meteorites, which range from delta 65Cu of +0.55 +/- 0.01 %o to +3.94 +/- 0.04 %o (per mil deviation of the 65Cu/63Cu from the NIST SRM 976 standard), independent of mare basalt Ti content. The delta 65Cu values of the basalts are negatively correlated with their Cu contents, which is interpreted as evidence for volatile loss upon mare basalt emplacement, plausibly related to the presence Cl- and S-bearing ligands in the vapour phase. This relationship can be used to determine the Cu isotopic composition of the lunar mantle to a delta 65Cu of +0.57 +/- 0.15 %o. The bulk silicate Moon (BSM) is 0.5%o heavier than the bulk silicate Earth (+0.07 +/- 0.10 %o) or chondritic materials (from -1.45 +/- 0.08 %o to 0.07 +/- 0.06 %o). Owing to the ineffectiveness of sulfide segregation and lunar core formation in inducing Cu isotopic fractionation, the isotopic difference between the Moon and the Earth is attributed to volatile loss during the Moon-forming event, which must have occurred at- or nearequilibrium.

期刊论文 2025-04-15 DOI: 10.1016/j.epsl.2025.119250 ISSN: 0012-821X

The formation and evolution of rocky planets such as the Earth are marked by the heavy bombardments that dominated the first parts of the accretions. The outcomes of the large and giant impacts depend on the critical points and liquid-vapor equilibria of the constituent materials. Several determinations of the positions of the critical points have been conducted in the last few years, but they have mainly focused on systems devoid of volatiles. Here, we study, for the first time, a volatile-rich ubiquitous model mineral, phlogopite. For this, we employ ab initio molecular dynamics simulations. Its critical point is constrained in the 0.40-0.68 g/cm3 density range and 5,000-5,500 K temperature range. This shows that adding volatiles decreases the critical temperature of silicates while having a smaller effect on the critical density. The vapor phase that forms under cooling from the supercritical state is dominated by hydrogen, present in the form of H2O, H, OH, with oxygen and various F-bearing phases coming next. Our simulations show that up to 93% of the total hydrogen is retained in the silicate melt. Our results suggest that early magma oceans must have been hydrated. In particular for the Moon's history, even if catastrophic dehydrogenation occurred during the cooling of the lunar magma ocean, the amount of water incorporated during its formation could have been sufficient to explain the amounts of water found today in the last lunar samples.

期刊论文 2025-04-01 DOI: 10.1029/2024JE008839 ISSN: 2169-9097

Observations of widespread hydration across the lunar surface could be attributed to water formed via the implantation of solar wind hydrogen ions into minerals at the surface. Solar wind irradiation produces a defectrich outer rim in lunar regolith grains which can trap implanted hydrogen to form and store water. However, the ability of hydrogen and water to be retained in space weathered regolith at the lunar surface is not wellunderstood. Here, we present results of novel and coordinated high-resolution analyses using transmission electron microscopy and atom probe tomography to measure hydrogen and water within space weathered lunar grains. We find that hydrogen and water are present in the solar wind-damaged rims of lunar grains and that these species are stored in higher concentrations in the vesicles that are formed by solar wind irradiation. These vesicles may serve as reservoirs that store water over diurnal and possibly geologic timescales. Solar windderived water trapped in space weathered rims is likely a major contributor to observations of the widespread presence, variability, and behavior of the water across the lunar surface.

期刊论文 2025-02-01 DOI: 10.1016/j.epsl.2024.119178 ISSN: 0012-821X

Volcanic products returned from the Apollo missions over 50 years ago provide a unique perspective into the magmatic evolution of the Moon. However, questions remain regarding the volatile loss, crystallization, and emplacement histories of lunar lavas. To address gaps in our understanding of the eruptive histories of lunar lavas, we investigate phase chemistry and 3D morphologies of low-titanium Apollo 15 basalts belonging to the olivine-normative and quartz-normative suites. We report the 2D and 3D petrography, mineral chemistry, and 3D void space morphologies of 15499, 15555, 15556, and the lesser studied 15495 and 15608 basalts. Quantitative apatite chemistry shows a wide range of apatite volatile compositions and that low-Ti basalt 15495 may contain the most OH-rich compositions measured from the Moon. Analyses of metal grains within the low-Ti basalts have expanded the field of expected Ni and Co metal concentrations for Apollo 15 mare basalts and are used to determine the petrogenesis of two of the studied samples. Coupling 2D chemistry with nondestructive 3D morphologic analyses provides critical insights on the relative timing of volatile exsolution in low-titanium lavas. Through the analysis of vesicles and vugs from X-ray computed tomographic data, we report the first 3D void space volume percentages for a suite of low-Ti basalts and show that these basalts degassed before the onset of mesostasis (e.g., apatite) crystallization. We use calculated cooling rates and 3D morphologic analyses to show that the studied basalts crystallized at various depths in separate lava flows, and 15608 represents the quenched margin of a mare flow. Our work highlights the value of combining 2D and 3D analytical techniques to study the emplacement history of basalts that lack geological context.

期刊论文 2025-01-15 DOI: 10.1016/j.gca.2024.10.018 ISSN: 0016-7037

Volatile organic compounds (VOCs) are a class of organic compounds that are easily volatilized at room temperature, causing serious damage to the human body, soil, and water bodies, and affecting the balance of the ecosystem. Cobalt tetraoxide (Co3O4) has a very high catalytic degradation ability for VOCs and is considered to be one of the metal oxides with the greatest potential to replace precious metal catalysts. Relevant studies have shown that Co3O4 catalysts prepared under different conditions have excellent photocatalytic and thermocatalytic activities. This paper discusses the effects of precursors, precipitants, reaction temperatures, and subsequent heat treatment temperatures on the catalytic degradation activity of benzene by the prepared Co3O4 catalysts. The activity differences of the samples were determined by the degradation rate of 15 mu L benzene and the CO2 generation rate of the Co3O4 catalysts prepared under different conditions at 290 degrees C, and the optimized preparation scheme of the Co3O4 catalyst with high catalytic activity was obtained. The study found that the Co3O4 catalyst prepared with cobalt acetate as a precursor, urea as a precipitant, 90 degrees C reaction, and subsequent 300 degrees C calcination showed the best activity in photothermocatalytic degradation of VOCs. The optimal Co3O4 catalyst had a catalytic degradation rate of 95.3% for 15 mu L benzene in only 5 min, and maintained a catalytic degradation rate of more than 95% for 15 mu L benzene after 10 photothermocatalytic degradation stability tests, proving its good catalytic stability. Combined with the test characterization results of XRD, SEM, UV-Vis-IR, TG, etc., the reasons for the difference in catalytic degradation efficiency of Co3O4 catalysts were explored: Co3O4 catalysts prepared under different conditions have different absorption capacities for ultraviolet-visible-infrared light, and calcination at a too high temperature will increase the surface area of the Co3O4 catalyst, resulting in a reduction in its active attachment sites. The optimal Co3O4 catalyst was further analyzed for photocatalysis at room temperature, thermocatalysis at different temperatures, and photothermocatalytic activity. It was found that its photothermal synergistic catalytic efficiency at 200, 240, and 290 degrees C was always greater than the simple sum of photocatalysis and thermocatalysis. The activation energy of the photothermal catalytic reaction is lower than that of the thermal catalytic reaction. Due to the reduction of activation energy, photothermal synergistic catalysis can significantly accelerate the reaction rate. The electron or energy excitation caused by the participation of light can trigger more reactant molecules to cross the energy barrier and accelerate the reaction. The photogenerated holes generated by photocatalysis can promote the release of lattice oxygen, thereby accelerating the formation of oxygen vacancies. Photogenerated electrons can reduce the reduction energy barrier of oxygen molecules during the reaction, accelerate the adsorption and dissociation of oxygen, allow oxygen vacancies to be quickly refilled, and restore the activity of the catalyst. Therefore, the Co3O4 catalyst has a photothermal synergistic effect in the catalytic degradation of VOCs, that is, the active species O2-, OH and C6H6+ produced by photocatalysis are more active than O-2, H2O and C6H6 participating in the reaction in traditional thermocatalysis, which accelerates the thermocatalytic redox of Co3O4.

期刊论文 2025-01-01 DOI: 10.1360/TB-2024-0970 ISSN: 0023-074X

Numerous missions to the Moon have identified and documented volatile deposits associated with permanently shadowed regions. A series of science goals for the Artemis Program is to explore these volatile deposits and return samples to Earth. Volatiles in these reservoirs may consist of a variety of species whose stable isotope characteristics could elucidate both their sources and the processes instrumental in their formation. For example, the delta D of potential contributors to the deposits can be used to identify a uniquely light solar wind component. Because of the exceptionally low temperatures of these volatile deposits, examining and interpreting their stable isotope systems to fulfill Artemis science goals through sampling, preserving, curating, and analyzing these samples are far more difficult than for other sample return missions. Collecting and preserving the samples at cryogenic temperatures dramatically increases science yield but is technologically demanding and poses increased risk during transport.

期刊论文 2024-12-24 DOI: 10.1073/pnas.2321071121 ISSN: 0027-8424
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