Electron microscopy of micron-sized lunar soil

We have performed electron-microscopic analysis on 0.5-1.0µm grains in order to study radiation damage by the solar-wind. We are reporting some interesting results we have found in monomineralic grains from core sample 15010,1130. This is a submature soil which has been studied for rare gas abundance and ferromagnetic resonance by (1) and modal petrology by (2).

Development of the gas chromatograph – mass spectrometer to investigate volatile species in the lunar soil for the Luna-Resurs mission

Since the analysis of the lunar rocks and soil samples, brought to Earth by the Apollo missions, it is believed that the Moon has a waterless nature and also other volatile species are strongly depleted. Advancement in analysis techniques helped to identify water and other volatile species in lunar volcanic glasses. Additionally, recent lunar space missions detected water and volatile organic compounds in the region of the lunar poles where permanently shadowed craters are existing. All known lunar soil samples available on Earth come from the lunar near side, close to the equator. To verify the most recent measurement results and to enhance the knowledge of the geological history of the Moon it is of high interest to perform in situ measurements on the lunar poles. For this reason the Russian space agency, Roskosmos, developed aprogram for the scientific exploration of the lunar poles. The Gas Analysis Package (GAP) is part of the selected scientific payload aboard the Luna-Resurs Lander. This instrument uses pyrolytic cells and will apply laser spectroscopy, gas chromatography and mass spectrometry to detect and analyze volatile components trapped in the lunar soil. An existing ion optical design of a compact reflectron type time-of-flight mass spectrometer, originally built for the MEAP/P-BACE balloon mission, was chosen as a part of the GAP instrument. The scope of this thesis is the development of the interface between gas chromatography (GC) and this Neutral Gas Mass Spectrometer (NGMS) to perform coupled GC-MS measurements. In the first part of this thesis the interfacing concept was developed and verified by coupling the NGMS prototype to gas chromatography. The second part of this thesis is devoted to the development of the NGMS flight version.

Prototype of the gas chromatograph-mass spectrometer to investigate volatile species in the lunar soil for the Luna-Resurs mission

In preparation for the Russian Luna-Resurs mission we combined our compact time-of-flight mass spectrometer (TOF-MS) with a chemical pre-separation of the species by gas chromatography (GC). Coupled measurements with both instruments were successfully performed with the prototype of the mass spectrometer and a flight-like gas chromatograph. The system was tested with two test gas mixtures, a mixture of hydrocarbons and a mixture of noble gases. Due to its capability to record mass spectra over the full mass range at once with high sensitivity and a dynamic range of up to 10(6) within 1 s, the TOF-MS system is a valuable extension of the GC analytical system. Based on the measurements with calibration gases performed with the combined GC-MS prototype and under assumption of mean characteristics for the Moon's regolith, the detection limit for volatile species in a soil sample is estimated to 2.10(-10) by mass for hydrocarbons and 2.10(-9) by mass for noble gases. (C) 2015 Elsevier Ltd. All rights reserved.

Depth-sensitive analysis of fluorine on lunar sample surfaces and in carbonaceous chondrites by a nuclear resonant reaction technique

The nuclear resonant reaction ¹⁹F(ρ,αγ)¹⁶O has been used to perform depth-sensitive analyses of fluorine in lunar samples and carbonaceous chondrites. The resonance at 0.83 MeV (center-of-mass) in this reaction is utilized to study fluorine surface films, with particular interest paid to the outer micron of Apollo 15 green glass, Apollo 17 orange glass, and lunar vesicular basalts. These results are distinguished from terrestrial contamination, and are discussed in terms of a volcanic origin for the samples of interest. Measurements of fluorine in carbonaceous chondrites are used to better define the solar system fluorine abundance. A technique for measurement of carbon on solid surfaces with applications to direct quantitative analysis of implanted solar wind carbon in lunar samples is described.

High porosity chained aggregates from the topsoil of the lunar regolith dust

The unusual behaviour of fine lunar regolith like stickiness and low heat conductivity is dominated by the structural arrangement of its finest fraction. Here, we show the previously unknown phenomenon of a globular 3D superstructure within the dust fraction of regolith. A study using the recently developed Transmission X-ray Microscopy (TXM) with tomographic reconstruction reveals a highly porous network of cellular voids in the finest dust fraction aggregates in lunar soil. Such porous chained aggregates are composed of sub-micron particles that form a network of cellular voids a few micrometers in diameter. Discovery of such a superstructure within the finest fraction of lunar topsoil enables a model of heat transfer to be constructed.

High porosity chained aggregates from the topsoil of the Lunar regolith Dust

The unusual behaviour of fine lunar regolith like stickiness and low heat conductivity is dominated by the structural arrangement of its finest fraction in the outer-most topsoil layer. Here, we show the previously unknown phenomenon of building a globular 3-D superstructure within the dust fraction of the regolith. New technology, Transmission X-ray Microscopy (TXM) with tomographic reconstruction, reveals a highly porous network of cellular void system in the lunar finest dust fraction aggregates. Such porous chained aggregates are composed of sub-micron in size particles that build cellular void networks. Voids are a few micrometers in diameter. Discovery of such a superstructure within the finest fraction of the lunar topsoil allow building a model of heat transfer which is discussed.

模拟月壤研制与月壤的微波辐射特性研究

嫦娥一号绕月探测卫星上将搭载一台四通道的微波探测仪（3.0 GHz、7.8GHz、19.3 5 GHz、37 GHz）。利用其测量到的月球微波辐射亮度温度，反演月壤厚度并评估月球的氦一3资源量是嫦娥一号卫星的四大科学目标之一。本文主要包括模拟月壤的研制和月壤微波辐射特性的研究，是对月球微波辐射探测的预先研究。（l）详细概述了月壤的形成与演化、化学和矿物组成、物理力学性质等；（2）模拟月壤的研制是嫦娥工程顺利开展所必需的基础设施建设项目，本文首次提出了系列化模拟月壤的研制设想和基本方案；（3）成功研制了CAS一1模拟月壤，岩石学、矿物学和地球化学的对比表明，CAS一1模拟月壤与APollo14登月点月壤相似。并测量了其基本的化学和物理力学性质供样品使用单位参考；（4）首次提出应用聚乙烯稀释法和Liehtenecker介电混合公式，在谐振腔微扰系统上测量干燥岩石或矿物复介电常数的方法，该方法具有操作简单、所需样品量少、测量精度高等优点；（5）利用同轴终端法系统测量了120 GHz模拟月壤、模拟月岩的复介电常数，研究其随颗粒粒度和（％TiO2＋％FeO＋％Fe2O3）含量的变化规律，并比较其与地球红土的差异；（6）在对月球物质的复介电常数进行详细研究的基础上，探讨了月壤的微波辐射特性，并估算了Apollo和Luna登月点的微波辐射在月壤中的穿透深度。

Interactions between soil, toxicant, and a lux-marked bacterium during solid phase-contact toxicity testing

Bioluminescence-based, solid-contact toxicity assays allow test bacterium and toxicant to interact at the solid-solution interface. A lux- marked bacterium, Burkholderia sp. RASC, and 2,4-dichlorophenol (2,4-DCP) were used to characterize these interactions. In the basic bioassay, cells were added to soil slurries containing 2,4-DCP (0-120 μg ml^-1). After 15 min, soil was removed by centrifugation, and bioluminescence in the supernatant was determined. Investigation of 2,4-DCP adsorption to soil revealed that sorption was linear and not significantly (p > 0.1) affected by the presence of Burkholderia cells. The numbers of culturable Burkholderia cells in the assay supernatant were 48.2 to 64.8% of the inoculum and independent of the soil weight. The effect of soil on 2,4-DCP toxicity was investigated by comparing soil aqueous extract and contact assays. The percentage bioluminescence for the contact assay was consistently higher than the extract assay at all test concentrations, and counts of viable Burkholderia cells were enhanced by the presence of 2,4-DCP in the contact assay. Expressing results as specific bioluminescence decreased the variability in response and the discrepancy in results between the two protocols. We suggest that solid-contact assays need improvement to ensure defined contact between cells and solid phase, and that the reporting of specific activity should be emphasized.

Introducing Acacia mangium trees in Eucalyptus grandis plantations: consequences for soil organic matter stocks and nitrogen mineralization

Background and aims Eucalyptus plantations cover 20 million hectares on highly weathered soils. Large amounts of nitrogen (N) exported during harvesting lead to concerns about their sustainability. Our goal was to assess the potential of introducing A. mangium trees in highly productive Eucalyptus plantations to enhance soil organic matter stocks and N availability. Methods A randomized block design was set up in a Brazilian Ferralsol soil to assess the effects of mono-specific Eucalyptus grandis (100E) and Acacia mangium (100A) stands and mixed plantations (50A:50E)on soil organic matter stocks and net N mineralization. Results A 6-year rotation of mono-specific A. mangium plantations led to carbon (C) and N stocks in the forest floor that were 44% lower and 86% higher than in pure E. grandis stands, respectively. Carbon and N stocks were not significantly different between the three treatments in the 0-15 cm soil layer. Field incubations conducted every 4 weeks for the two last years of the rotation estimated net soil N mineralization in 100A and 100E at 124 and 64 kg ha(-1) yr(-1), respectively. Nitrogen inputs to soil with litterfall were of the same order as net N mineralization. Conclusions Acacia mangium trees largely increased the turnover rate of N in the topsoil. Introducing A. mangium trees might improve mineral N availability in soils where commercial Eucalyptus plantations have been managed for a long time.

Effects of nitrogen source and ectomycorrhizal association on growth and delta N-15 of two subtropical Eucalyptus species from contrasting ecosystems

Ectomycorrhizal (EM) associations facilitate plant nitrogen (N) acquisition, but the contribution of EM associations to tree N nutrition is difficult to ascertain in ecosystems. We studied the abilities of subtropical EM fungi and nutritionally contrasting Eucalyptus species, Eucalyptus grandis W. Hill ex Maiden and Eucalyptus racemosa Cav, to use N sources in axenic and soil cultures, and determined the effect of EM fungi on plant N use and plant N-15 natural abundance (delta N-15). As measured by seedling growth, both species showed little dependence on EM when growing in the N-rich minerotrophic soil from E. grandis rainforest habitat or in axenic culture with inorganic N sources. Both species were heavily dependent on EM associations when growing in the N-poor, organotrophic soil from the E. racemosa wallum habitat or in axenic culture with organic N sources. In axenic culture, EM associations enabled both species to use organic N when supplied with amide-, peptide- or protein-N. Grown axenically with glutamine- or protein-N, delta N-15 of almost all seedlings was lower than source N. The delta N-15 of all studied organisms was higher than the N source when grown on glutathione. This unexpected N-15 enrichment was perhaps due to preferential uptake of an N moiety more N-15-enriched than the bulk molecular average. Grown with ammonium-N, the delta N-15 of non-EM seedlings was mostly higher than that of source N. In contrast, the delta N-15 of EM seedlings was mostly lower than that of source N, except at the lowest ammonium concentration. Discrimination against N-15 was strongest when external ammonium concentration was high. We suggest that ammonium assimilation via EM fungi may be the cause of the often observed distinct foliar delta N-15 of EM and non-EM species, rather than use of different N sources by species with different root specialisations. In support of this notion, delta N-15 of soil and leaves in the rainforest were similar for E. grandis and co-occurring non-mycorrhizal Proteaceae. In contrast, in wallum forest, E. racemosa leaves and roots were strongly N-15-depleted relative to wallum soil and Proteaceae leaves. We conclude that foliar delta N-15 may be used in conjunction with other ecosystem information as a rapid indicator of plant dependency on EM associations for N acquisition.