Sc Contents Research Articles

The composition of CI chondrites and their contents of chlorine and bromine: Results from instrumental neutron activation analysis

AbstractBetween 1973 and 1994, 15 samples of CI chondrites were analyzed by neutron activation analysis at the Max‐Planck‐Institute for Chemistry, Department of Cosmochemistry in Mainz, Germany. The analyses comprise nine Orgueil samples and three samples of Ivuna, two of Alais and one of Tonk. Samples came from various sources and had masses between 5 and 600 mg. Most data are published here for the first time. The results for the nine Orgueil samples demonstrate the essentially homogeneous chemical composition of Orgueil at a level of a few milligrams. The analytical results of Ivuna, Alais, and Tonk agree, with only few exceptions, with the results of Orgueil analyses. All samples agree within ±3% in their contents of Sc, Ir, Cr, Fe, Co, Zn, and Se. The elements Sc and Ir represent the refractory component; Cr, Fe, and Co the main component; and Zn and Se the volatile component. Thus, in all CI chondrites there are essentially the same fractions of the fundamental cosmochemical components. The essentially identical chemical composition of all samples shows that their water contents are constant at about 20 ± 5 wt%. There is excellent agreement between the data listed here with data reported in the relevant literature. There is no doubt that the CI composition is a well‐defined entity, which is thought to represent the non‐gaseous compositions of the solar nebula and the photosphere of the Sun. In addition, we conclude that the recently proposed new CI chondritic chlorine and Br values are too low, when compared to earlier measurements.

Geochemical behavior of rare metals and high field strength elements during granitic magma differentiation: A record from the Borong and Malashan Gneiss Domes, Tethyan Himalaya, southern Tibet

In the Borong Gneiss Dome and Malashan Gneiss Dome within the Tethyan Himalaya, zircon UPb ages and whole-rock geochemical data demonstrate that at least two episodes of leucogranite formed at 19.8–19.4 Ma and 18.6–18.5 Ma, respectively. Each of them contains at least two suites of granite: two-mica granite and garnet-bearing leucogranite. Although the two types of granites are characterized by distinct element geochemistry and mineral compositions, they show similar Sr-Nd-Hf isotope ratios and regular variations in the compositions of whole-rock elements. From two-mica granite to garnet-bearing leucogranite, SiO2, Na2O, Rb, Nb, and Ta contents and Rb/Sr ratios increase; in contrast, Al2O3, CaO, MgO, FeO, TiO2, Sr, Ba, Eu, Zr, U, Th, light rare earth elements (LREEs) and Sc contents, as well as Zr/Hf and Nb/Ta ratios, decrease. Such systematic variations imply that two-mica granite and garnet-bearing leucogranite are cogenetic and that two-mica granite represents the more primary melt, whereas garnet-bearing leucogranite is a more evolved melt. During granitic magma evolution, fractional crystallization induces substantial changes in the melt structure and in turn major changes in the dissolution behavior of accessory phases (e.g., zircon, monazite, and apatite) and the geochemistry of key trace elements. Such changes might be the key factors that resulted in the subordinate W-Sn-Nb-Ta-Be anomalies in the more evolved granites, which implies that the Himalayan Cenozoic leucogranites have high potential to produce economic rare metal deposits.

Geological and geochemical characteristics of karst bauxite-bearing sequences in Xiabu area, Central Shanxi Province, North China

Karst bauxite resources are widespread in the Shanxi Province, accounting for the richest bauxite resources in China. The Shanxi bauxite deposits are hosted in the lower member of the Carboniferous Benxi Formation, which consists of karst bauxite-bearing sequences. In addition to being main economic source of aluminum, there are many critical metals in the karst bauxite-bearing sequences.The spidergram pattern, REE pattern, immobile element tracing, and CrNi bivariate plots, as well as the previous studies on detrital zircons of North China Craton (NCC) bauxite ores, show that iron-rich clays were mainly weathered from the underlying carbonates, whereas the bauxite ore and top clay have allochthonous protoliths. Based on field investigations and geochemical characteristics of five typical drillcore sections in the Xiabu area, as well as previous researches, we concluded four sedimentary successions and we perfected the geological model of the karst bauxite-bearing sequences in central NCC. The Ordovician carbonate bedrocks developed many paleokarst terrain on the NCC, which experienced 150 Myr of karstification and denudation from the Middle Ordovician. Paleokarst terrain determines the distribution and thickness of the iron-rich clay layer. And the iron-rich clay above or below the groundwater table are separated into red Shanxi-type iron or clay (Fe3+-bearing minerals) and grey clay (Fe2+-bearing minerals). Until the Late Carboniferous, the sedimentation suddenly occurred in the NCC. New sediments were predominantly source materials for bauxite deposits, which were primarily controlled by the landform of the discontinuous weathered iron-rich clay. Furthermore, the humid and warm climate conditions reinforce the intensity of chemical weathering and microorganism participation, which also contributes to the formation of bauxite ore layer and top clay layer.The bauxite-bearing sequences in the Xiabu area contain high contents of critical elements such as U, Th, REEs, and Sc. In this study, high-level natural radioactivity was detected in the bauxite ore layer through gamma-ray logging of vertical sections. The correlation analysis revealed that the highly elevated U and Th contents in the bauxite ore layer are positively correlated with the natural radioactivity. Therefore, utilizing the gamma-ray logging method is effective in prospecting concealed karstic bauxite deposits. The REEs are also highly enriched in the bauxite ore layer and are positively correlated with P and Sr, indicating that the REEs are mainly hosted by phosphate minerals. The Sc contents of red clay are extremely high (up to 206.7 μg/g; average 118 μg/g), reaching industry standards levels. The integrated utilization of critical metals of the bauxite-bearing sequences is an important strategy for facing the significant supply crisis.

Geochemistry of subtropical arenosols from Kuito region (Angola). Urbanization effects and environmental implications

The city of Kuito, in a tropical highland region of central Angola, has grown rapidly over the past few decades. Although industrialization is minor, the city evolved with poor planning and road traffic have been soaring. Physicochemical properties of two sets of soil samples, natural and urban, are compared to assess the transformations achieved during the last decades in association with human occupation. Compared to natural soil, urban soils have significantly higher pH and electrical conductivity. Because of the association with quartz-rich sandy units, regional arenosols are impoverished in most minor and trace elements. Urban soil has significantly lower contents of Al, Ga, Sc, V and Zr and significantly higher contents of Ca, Na, P and several potentially toxic elements (PTE) than natural soil. A comparison with natural background levels reveals PTE enrichments ranked as Cd > Zn > Sb > Ba > Pb > Hg > Cu > Sn. In peripheric areas of Kuito, urbanization-related geochemical disturbances are mainly limited to enrichment in Ca, Na and P, and depletion in elements that tend to concentrate in fine-grained fractions; but soils in central areas tend to hold significant, although variable, amounts of PTE. PTE enrichment relative to a Si-rich background partially explain the high values of PLI (pollution load index) and PERI (potential ecological risk index), with environmental deterioration promoted by local contents of Pb, Zn, Cu and Cr. However, only the concentrations of Pb, and occasionally As, Ba, Cu, Hg and Zn, surpass available environmental guideline values. The present work shows that even without industrial activities, recent urbanization changed tropical arenosol geochemistry and can be responsible for significant enrichment in PTE.

Fully epitaxial ferroelectric ScAlN grown by molecular beam epitaxy

We report on the demonstration of ferroelectricity in ScxAl1-xN grown by molecular beam epitaxy on GaN templates. Distinct polarization switching is unambiguously observed for ScxAl1-xN films with Sc contents in the range of 0.14–0.36. Sc0.20Al0.80N, which is nearly lattice-matched with GaN, exhibiting a coercive field of ∼ 4.2 MV/cm at 10 kHz and a remnant polarization of ∼135 μC/cm2. After electrical poling, Sc0.20Al0.80N presents a polarization retention time beyond 105 s. No obvious fatigue behavior can be found with up to 3 × 105 switching cycles. The work reported here is more than a technical achievement. The realization of ferroelectric single-crystalline III–V semiconductors by molecular beam epitaxy promises a thickness scaling into the nanometer regime and makes it possible to integrate high-performance ferroelectric functionality with well-established semiconductor platforms for a broad range of electronic, optoelectronic, and photonic device applications.

Geochemical characteristics, provenance and paleodepostional environment of the Lower Jurassic Huxishan Formation in the Lenghu area, northwestern Qaidam Basin, North West China: Implications for organic matter origin

The organic-rich mudstone of Lower Jurassic Huxishan Formation (J1h) in the Lenghu area is the main oil prone source rocks in the northwestern Qaidam Basin. However, the evolution of dispositional environment and the provenance of dispositional rocks and organic matter are still unclear. Based on the data of element contents, total organic carbon and biomarkers of 143 samples, this study aims to investigate the provenance, paleoclimate, paleowater environment and origin of organic matter. The samples show high contents of terrigenous elements Ti, Sc, La and Co. Moreover, the Ti/Zr–La/Sc, La–Th–Sc, SiO2–K2O/Na2O and K2O/Na2O–SiO2/Al2O3 discrimination diagrams indicate that the tectonic settings of the provenance are oceanic island arc and continental island arc. Weight ratios of Ti/Zr, La/Sc and Th/Co of the J1h samples show values of 6.86–204.08, 0.19–2.16 and 0.015–0.123, which demonstrate a common source of clasts from mafic rocks. The Co/Th–La/Sc and La/Th–Hf discrimination diagrams also indicate that the provenance is mafic rocks with background of oceanic island arc, suggests that the provenance came from different stages in the subduction of the regional ocean and land in the Early Paleozoic. The weathering indices suggest that the samples faced moderate to intense weathering, combining with climate indices, illustrate that the paleoclimate was warm and humid, and the precipitation showed an increased trend from bottom to top. The values of CaO/MgO·Al2O3 show a decreased trend, implying that the paleotemperature had a decreased trend and the average annual temperature was less than 14.2 °C. The values of Sr/Ba, Rb/K and discrimination diagram of Pr/nC17–Ph/nC18–Pr/Ph indicate that the paleowater was predominantly fresh water with occasional brackish and salt water, which also provide evidence of lower salinity of water within the lower strata and increased salinity (fresh water to salt water) within the middle and upper of the strata. The values of V/(V + Ni), V/Cr, U/Th and Pr/Ph indicate that the samples mainly deposits in weak to moderate reducing environment. The reduction degree decreased first and then increased from bottom to top with a few oxidation sections are distributed in the middle of the formation, which indicate a process of lake regression and transgression. The paleoproductivity during organic-rich mudstone sedimentation was high in terms of P/Ti, Cu + Ni + Zn and TOC (1.99%–22.59%), which have a positive trend with paleosalinity. This indicates that the water with higher salinity is more active in nutrient supply. The productivity from large to small is the middle section, the upper section and the lower section, respectively. The homologous series of C27, C28 and C29 regular steranes, main carbon number perks, maximum carbon number, Ph/nC18–Pr/nC17 and ∑nC21-/∑nC22+ all indicate that the source of the organic matter during the J1h organic-rich mudstone was mainly terrestrial higher plants, the proportion of algae and phytoplankton increased in the upper section. The results show that the organic-rich mudstones of the Huxishan Formation developed under the background of lake regression and lake transgression. The dispositional environment and organic types of huxishan formation are obviously different in different sections.

Geochemical constraints on the mobilization of Ni and critical metals in laterite deposits, Sulawesi, Indonesia: A mass‐balance approach

AbstractIndonesia is one of the largest Ni ore producers in the world and is also expected to be an important potential source of some critical metals (e.g., Co, Sc, rare‐earth elements, and platinum‐group elements). However, few studies have examined Ni laterite deposits in this country. In this study, we investigate Ni enrichment and the potential accumulation of critical metals in four laterite profiles with varying degrees of serpentinization and weathering intensity in the Soroako and Pomalaa mining areas of Sulawesi, Indonesia. We integrate geochemical evaluation with a mass‐balance approach and mineralogical analysis to better constrain the geochemical factors influencing the mobilization of Ni during lateritization. Nickel contents in the saprolite horizon of the profiles that are strongly weathered and developed over serpentinized peridotite are higher than those that are weakly weathered and developed over unserpentinized harzburgite. The bulk Ni contents of saprolite horizons are related to Ni contents of Ni‐bearing Mg‐phyllosilicates, which suggests that Ni remobilization is the main control on Ni enrichment in the profiles. Mass‐balance calculations reveal that the amounts of gained Fe and Ni in the profiles are positively correlated. This relationship indicates that the redistribution of Ni is likely controlled by the aging of Ni‐bearing goethite (dissolution/recrystallization) involving ligand‐promoted dissolution by organic matter and/or reductive dissolution by microbial activity near the surface. Critical metals show enrichment in specific horizons. Enrichments in Co and rare‐earth elements are strongly influenced by the formation of Mn‐oxyhydroxides in the oxide zone of the profiles. In contrast, Sc, Pt, and Pd show residual enrichment patterns, with grades influenced mainly by their initial contents in bedrock. The profiles show a positive correlation between Sc and Fe, as reported for other Ni laterite deposits. Among the critical metals, Sc, Pt, and Pd contents in the studied profiles are comparable with values reported from other Ni laterite deposits worldwide.

Comparison of Antioxidant and Antibacterial Activities of Camellia Oil From Hainan With Camellia Oil From Guangxi, Olive Oil, and Peanut Oil.

Background/Aim: Camellia oil from Hainan (SY) is a unique vegetable oil in Hainan, China, due to the geographical environment and oil extraction only through simple physical treatments. To compare SY with camellia oil from Guangxi (SC), olive oil (GL), and peanut oil (HS), this study analyzed the antioxidant and antibacterial activity of four vegetable oils.Methods: Using Gallic acid, BHT as the control, Saccharomyces cerevisiae as the model organism, the antioxidant activities of vegetable oils were measured in vitro and in vivo, and the antibacterial activity was measured with the minimum inhibitory concentration (MIC) method.Results: The major contents of SY, SC, and HS were oleic Acid; the major content of GL was squalene. The highest total flavonoids content of SY was 39.50 ± 0.41 mg RE/g DW; and the highest total phenolic content of SC was 47.05 ± 0.72 mg GAE/g DW. SY exhibited the strongest scavenging activity of hydroxyl radical (HO·) and superoxide anions (), the IC50 value were 2.06 mg/mL, 0.62 mg/mL, respectively; and SC showed the strongest DPPH· and ABTS· scavenging activity and the reducing abilities. SY showed excellent effect on survival rate, protection rate, flavonoids uptake of S. cerevisiae cells, decreased MDA content and ROS level, inhibited CAT, POD, and GR enzyme activity. The absorption of SC total phenols was the highest by cells. The activity showed GL had a broad-spectrum antibacterial activity.Conclusion: Thus, SY shows potential antioxidant activity and provides an important reference value for people to choose edible vegetable oils.

Effects of Sc addition on microstructure, mechanical and corrosion resistance properties of 7055 Al alloy

This research investigates the influences of different contents of Sc on the microstructure, mechanical, electrical conductivities and corrosion resistance properties of 7055 alloy. The effect of Sc can increase the non-uniform nucleation of the alloy and significantly refine the casting structure of the alloy. In addition, the addition of Sc not only inhibits grain coarsening, pins GBs and restrains recovery and recrystallisation, but also maintains the effect of fibre structure during the formation of high-density nano-Al3 (Sc, Zr) phase precipitation. Compared with pure 7055 alloys, the hardness, tensile strength, elongation, electrical conductivity and corrosion resistance of 7055 alloys with Sc are improved remarkably. After adding a little Sc, the grain size of the alloy is refined from 80um to 40um, and the properties of the alloy are improved. When Sc content is 0.25%, the tensile strength of the alloy increases from 623.1mpa to 685.9mpa, and the self-etching current density decreases from 1.56 × 10−5 to 8.74 × 10−7, and the corrosion resistance is also greatly improved.

Hypogene kaolin deposits from felsic intrusive rocks (Peninsular Malaysia) with special reference to rare earth elements and stable isotopes geochemistry

Clay fractions of the hypogene kaolin deposits from Ipoh granite and Jerai pegmatite are composed of kaolinite, while the greenish kaolin horizon of Ipoh area comprises of illite and kaolinite. Al2O3 and SiO2 are the main constituents in the studied kaolins with very low concentrations of other oxides. K2O occurs in relatively high contents in the illite-rich kaolin that formed by hydrothermal alteration of biotite-granite of the greenish kaolin horizon of Ipoh area. The higher contents of Ba, Cr, Cs, Ga, Rb, Sc, and Sn in the illite-rich horizon are inherited from its source rock. The relative enrichment of light rare earth elements (LREE) over heavy rare earth elements (HREE) as indicated from the high (La/Yb)n ratios and positive correlations between ΣREE and P2O5 in the studied kaolins suggest the occurrence of REE as authigenic florencite, churchite and/or rhabdophane and, therefore, reflect the kaolinitization process rather than the parent rocks. δH and δO values are similar in both Ipoh and Jerai kaolins with dH values range from −84 to −99‰ and positive δO values varying between 0.95 and 5.47%. H- and O-isotopes data fall close to the left side of the kaolinite line in equilibrium with meteoric water at temperatures of > 100 °C. The pronounced negative Eu anomalies, absence of positive Ce anomaly and high crystallization temperature (94–113 °C) indicate the hydrothermal (hypogene) origin of the studied kaolins as a result of the Triassic post-magmatic hydrothermal activities in Peninsular Malaysia. Mineralogical and geochemical variations among the studied deposits although they formed by the same kaolinitization process, suggest a significant role of parent rocks in their compositions.

Trace elements in olivine: Proxies for petrogenesis, mineralization and discrimination of mafic-ultramafic rocks

Olivine is a ubiquitous mineral in mafic-ultramafic rocks and has been widely used as a mineral marker in various geological processes. However, its development of trace elements is limited. Here we present newly-obtained trace element data 7Li, 27Al, 29Si, 31P, 43Ca, 45Sc, 49Ti, 51V, 53Cr, 55Mn, 59Co, 60Ni, and 66Zn of olivine in typical mantle xenoliths, mantle peridotites in ophiolites, and plutonic rocks from layered and Alaskan-type intrusions to develop trace element proxies for the petrogenesis, mineralization and discrimination of various mafic-ultramafic rocks. Residual olivine grains in mantle xenoliths and ophiolitic peridotites, which represent residues of mantle melting, have higher Ni/Co (>20) and Ni/Mn (>2) ratios than magmatic olivine (Ni/Co < 20, Ni/Mn < 2), which are consistent with the compatibilities of these elements during partial melting and magma differentiation. Lower Ni content, and lower Ni/Co and Ni/Mn ratios at a given Fo content can distinguish olivine in Alaskan-type intrusions from layered intrusions, reflecting the nature of their mantle sources. The V and Sc contents and V/Sc ratios in olivine can distinguish mantle xenoliths (V > 2 ppm, V/Sc > 0.5) from ophiolitic peridotites (V < 2 ppm, V/Sc < 0.5), indicating a more reduced state of continental lithospheric mantle compared to the oceanic lithospheric mantle. As a consequence, the four occurrences of mafic-ultramafic rocks can be distinguished by olivine with (Sc × 10)-(Ti × 2)-Zn and V/Sc-(Co/Ni × 2)-(Zn/Mn × 5) ternary diagrams. In addition, Li, Ti and P contents in olivine are good tracers of melt/fluid metasomatism, whereas Ni/Co, Ni/Mn and Mn/Zn ratios are indicators of chromite mineralization. Therefore, trace elements in olivine can be used as chemical proxies to distinguish the origin of various mafic-ultramafic rocks, as well as the processes by which they evolved.

Chemical and boron isotopic compositions of tourmaline at the Dachang Sn-polymetallic ore district in South China: Constraints on the origin and evolution of hydrothermal fluids

The Dachang Sn-polymetallic ore district in South China is the second largest tin district in the world with a tin reserve of over one million tonnes. Zn-Cu skarn and stratiform, massive, and vein Sn-Pb-Zn ores are all present in this district. This has led to a debate as to whether the Sn orebodies were formed by Cretaceous magmatic-hydrothermal replacement or Devonian submarine exhalative-hydrothermal sedimentation. Here, we present a systematic investigation of the major, trace element, and boron isotopic compositions of different types of tourmaline in the Dachang ore district. Tourmaline disseminated in the Longxianggai granite and pegmatite veins belongs to the schorl series and has high contents of Li, Zn, and Ga. The δ11B value of primary magma of the Longxianggai granite is estimated to be about −13‰, close to the global average δ11B value (−11‰) for S-type granites. Tourmaline from quartz-tourmaline veins in the Longxianggai granite has similar chemical composition to the magmatic tourmaline and likely formed from hydrothermal fluids exsolved from the evolved granitic melt. The δ11B value of the initial hydrothermal fluids is also calculated to be about −13‰. Tourmalines from the skarn and sulfide ores in the Lamo deposit have higher Mg/(Mg+Fe) and lower Na/(Na+Ca) ratios and higher contents of Be, Ge, Sr, and Sn than magmatic tourmaline. These patterns likely reflect input of elements derived from the host Devonian limestone. The δ11B values of the hydrothermal fluids are estimated to be between −13 and −10‰, suggesting evolved magmatic-hydrothermal fluids related to the Longxianggai granite. Tourmalines from the stratiform and vein ores in the Changpo-Tongkeng deposit are extremely Mg-rich and mostly belong to the dravite series. They have high contents of Sc, V, Cr, Sr, and Sn and show positive Eu anomalies. The δ11B values of these B- and Sn-rich fluids are estimated to be between −15 and −10‰, suggesting that the fluids also have a magmatic-hydrothermal origin. These fluids are most likely derived from the same granitic magma source, but may have interacted with the Devonian volcanic rocks.

Mineralogical and geochemical characteristics of altered volcanic ashes (tonsteins and K-bentonites) from the latest Permian coal-bearing strata of western Guizhou Province, southwestern China

Although the geochemical and mineralogical characteristics and provenance of Permian-Triassic boundary (PTB) widespread volcanic ashes from southern China have been well investigated, the volcanic ashes just prior to the end-Permian mass extinction (EPME) have rarely been studied. This paper presents the mineralogical and geochemical compositions of volcanic ashes from the latest Permian coal-bearing strata of southwest China. Based on the relative abundances of kaolinite and mixed-layer illite/smectite (I/S), the volcanic ashes in the present study can be divided into tonsteins and K-bentonites, which are dominated by kaolinite and I/S, respectively. The I/S in K-bentonites formed during burial diagenesis in a non-marine environment, indicated by their low contents of sulfur and low ratios of Sr/Ba. Based on the general geothermal gradient and vitrinite reflectance of coals, the I/S was deduced to have formed under a temperature less than 100 °C. Collectively, the occurrence of vermicular kaolinite, as well as high-temperature quartz and euhedral primary zircon identified in tonstein samples indicate an intermediate-felsic pyroclastic origin for the volcanic ashes, while rounded quartz and mica grains both in tonsteins and K-bentonites reflect the products of erosion from sediment source regions. The negative Eu anomalies, rare earth elements (REY) distribution patterns, low contents of Sc, V, Cr, Co, Ni and Zn, and Al2O3/TiO2 values, suggest that the tonsteins and K-bentonites are related to felsic volcanic eruptions. The relationship between Al2O3/TiO2 vs. Nb/Yb and Al2O3/TiO2 vs. Zr/TiO2 ratios indicate that the tonsteins and K-bentonites were derived from at least two felsic sources: (1) some distal volcanic arc(s) and (2) the top of the Kangdian Upland exposing the alkaline-felsic volcanic rocks formed during the waning activity of the Emeishan plume and the basement of the Kangdian Upland exposing older felsic rocks.

In-situ boron isotopic and geochemical compositions of tourmaline from the Shangbao Nb–Ta bearing monzogranite, Nanling Range: Implication for magmatic-hydrothermal evolution of Nb and Ta

The enrichment mechanism of tantalum and niobium are still in dispute due to complex textural features of Nb–Ta minerals. Tourmaline is an accurate passive geochemical monitor related to the W-Sn-Nb-Ta-Li mineralization, which can record Nb and Ta variations in melt/fluid. The newly discovered Shangbao Nb–Ta bearing monzogranite is located in Nanling Range, South China, which is characterized by tourmaline wide occurrence. In this paper, we systematically investigate the different types of tourmaline using in-situ major, trace elemental and boron isotope for studying the origin of tourmaline, boron source, and Nb–Ta enrichment process. Three types of tourmaline have been identified, namely, disseminated tourmaline (TD type) in monzogranite, nodular tourmaline (TN type), consisting of the yellow core (TNy type) and blue rim (TNb type), and veined tourmaline (TV type). Almost all tourmalines from the Shangbao Nb–Ta deposit exhibit very low Ca content, X-site occupancy and high ratio of Fe / (Fe + Mg), pertaining to the group of schorl and alkali. Trace elements primarily present the low concentrations of <10 ppm, while the contents of Sc, Li and Zn are higher.Based on the petrography and Al occupations in the Y-site of tourmaline, TD type tourmaline was precipitated straightly from the melt at the late magmatic stage, while TN type tourmaline crystallized during the magmatic-hydrothermal transition process, and TV type tourmaline was the origin of hydrothermal fluid. In-situ boron isotope analyses of TD and TN type tourmaline by MC-ICP-MS show the narrow δ11B values from −17.16‰ to −14.81‰, demonstrating the same boron source. TV type tourmaline shows the weak higher δ11B values of −14.48‰ to −13.46‰ likely resulted by Rayleigh fractionation. The concentration of Nb in TD and TV type tourmaline can reach up to 20 ppm, which is higher than that in TN type tourmaline. However, TN type tourmaline contains higher Ta content than other types, revealing magmatic-hydrothermal transitional stage is critical to Ta enrichment. Compared with tourmaline in other type deposits, tourmaline in Shangbao monzogranite contains high Nb and Ta contents, indicating that it is a suitable tool for exploration, and the tourmaline is available to targeting Nb and Ta mineralization.

Oxygen defect dominated photoluminescence emission of ScxAl1−xN grown by molecular beam epitaxy

A fundamental understanding and control of impurity incorporation and charge carrier recombination are critical for emerging ScxAl1−xN electronics, optoelectronics, and photonics. We report on the photoluminescence properties of ScxAl1−xN grown by plasma-assisted molecular beam epitaxy with varying growth temperatures and Sc contents. Bright and broad emission comprising a dominant peak at ∼3.52 eV and a weak peak at ∼2.90 eV was observed in Sc0.05Al0.95N. The origin of the ∼3.52 eV emission line is attributed to charge carrier recombination from the localized excited state of (Vcation-ON)2−/− to its ground state, whereas the second peak at ∼2.90 eV results from charge carrier recombination of isolated Vcation3−/2− to the valence band. We further show that oxygen defect-related emission can be significantly suppressed by increasing growth temperature. This work sheds light on the recombination dynamics of photoexcited carriers in ScxAl1−xN and further offers insight into how to improve the optical and electrical properties of ScxAl1−xN that are relevant for a broad range of applications.

Минералого-геохимическая специфика углеродистых пород окружения Усть-Карской астроблемы (Пай-Хой)

We studied Upper Paleozoic (P1pt-ng) carbonaceous shales and siltstones from the area of the Ust'-Kara astrobleme (PayKhoy). We analyzed mineralogical and geochemical features of carbonaceous rocks of the target in the vicinity of the Ust'-Kara astrobleme event using a complex of modern methods to identify possible mobilization, redeposition and concentration of ore substance under intensive post-impact hydrothermal activity. Geochemical features of carbon deposits, altered by post-impact hydrothermal processes in the vicinity of the Ust'-Kara impact structure, have been determined. We found anomalous contents of Ti, Mn, Cr, Zr, Ni, Li, Co, Sc and REE. Inherent rare metal and rare earth minerals (monazite, florensite), sulfides (pyrite, chalcopyrite, marcasite, sphalerite), apatite, barite, anatase, chrome spinels were diagnosed.

Evaluation of Quality Parameters of Food Barley (Hordeum Vulgare L.) Varieties as Affected by Blended NPSB Fertilizer Rates in Central Highlands of Ethiopia

Barley (Hordeum vulgare L.) is the most health benefits among cereal crops which were grown mostly in central highlands of Ethiopia. The three food barley varieties (EH1493, HB1966 and HB-1307) which were released by Holeta Agricultural Research Center (HARC) had experience on barley breeding program (his center of excellence) was evaluated for their grain flour quality content and proximate analysis with respective to five blended NPSB fertilizer rates (0, 100,150, 200 &amp; 250 kg NPSB ha -1 ) and one Recommended NP (60 kg N and 69 kg P 2 O 5 ha -1 ) fertilizer rates. To evaluate their proximate analysis and grain flour quality contents of the food barley varieties were determined by using suitable Standard Official procedures. Proximate analysis was determined according to Association of Official Agricultural Chemists (AOAC) method and TKW, MC, HLW, GS, GE, PC, FC, AC, CHO, SC, FC, and BG contents of food barley flour was analyzed. All quality and proximate analysis result means were statistically significant and in the range of acceptable recommendation according to FAO and other nutritional sources. The quality parameters analysis showed that EH1493 variety has an average moisture content (11.78%), Hectoliter weight (66.26%), and friability (68.43%), while grain size (80.46%) and Bet-glucan (861.81mgL -1 ) were higher with HB1966 variety. Moreover, 200kg NPSB ha -1 gave the maximum protein (10.31%), fat (2.51%), and ash (2.64%), while the highest total carbohydrate (82.88%) content obtained on 250kg NPSB ha -1 .The economic analysis revealed that the highest net benefit (69558.42 birr ha -1 ) with marginal rate of return of 1475.41% was recorded from the application of 200kg NPSB ha -1 with EH1493 variety. Therefore, application of 200 kg NPSB ha -1 with EH1493 variety is recommended to be used by farmers around Walmera district. Keywords: Food barley, NPSB fertilizers, proximate analysis, grain quality content DOI: 10.7176/FSQM/104-01 Publication date: January 31 st 2021

Quench sensitivity and microstructures of high-Zn-content Al−Zn−Mg−Cu alloys with different Cu contents and Sc addition

Abstract The Zn, Cu, and Sc contents of 7xxx Al alloys were adjusted according to the chemical composition of a 7085 Al alloy, and the effects of Zn and Cu contents and Sc addition on the microstructures, hardness, and quench sensitivity of the 7xxx Al alloys were studied. The alloys with high Zn content and Sc addition exhibited higher hardness than the 7085 alloy at the position 3 mm away from the quenching end. The density of η and T phases increased with the increase in Zn and Cu contents, and the Sc addition led to the formation of the Y phase and more η phases at the position 120 mm away from the quenching end. Compared with the 7085 alloy, the high Zn−high Cu and Sc-added alloys exhibited higher quench sensitivity, while the simultaneous increase in Zn content and decrease in Cu content could enhance the hardness and reduce the quench sensitivity of the 7085 alloy.

Predictive model of geographical origin discrimination of paper mulberry and handmade paper using ICP-AES/MS and multivariate statistical analysis

Abstract The fiber of paper mulberry, which is mostly grown in the East Asian region, varies in both length and width—even if from the same species—depending on the country, soil, and climate where it is grown. This accounts for differences in the quality of handmade paper between domestic and imported products. Once handmade paper is manufactured as sheets, its origin cannot be determined from a morphological perspective, regardless of macroscopic and microscopic observations. Therefore, this study attempted to determine the origin of Korean and imported products using mulberry bast fiber and handmade paper from a chemometrics perspective. The inorganic components of wood are absorbed from the soil and exist in the bark of trees; thus, metal and rare-earth elements in the bast fibers and handmade papers were quantitatively analyzed using inductively coupled plasma-atomic emission spectroscopy/mass spectrometry (ICP-AES/MS). Following this, a prediction model of their origin was constructed by applying multivariate statistical analysis, i.e., a partial least squares-discriminant analysis (PLS-DA) loading plot was constructed, which helped in identifying the discrimination factors resulting from their origin. According to the ICP-AES results, Pb was only detected in the Gyeongbuk Mungyeong dak sample of the Korean bast fibers. The Chinese bast fiber sample had high contents of Ca, and B and Zn were detected only in the Chinese bast fiber samples. Bast fiber samples from China, Japan, and Thailand showed relatively high contents of Al, Ca, and Na. Meanwhile, Cu and Zn were detected in the handmade paper manufactured from the imported materials. According to the ICP-MS results, among the Korean handmade papers, the products from Gyeongbuk Mungyeong, Andong, and Chungbuk Goesan exhibited a high U content and that from Gapyeong had high Sc, Rb, Sr, and Ba contents. Thus, the elemental analysis employed in this study effectively identified the origin of the papers. The origin prediction by PLS-DA for the domestic and imported products revealed an accuracy of 86.4% and 72.7% for ICP-AES and ICP-MS methods, respectively, which is deemed acceptable to assess the origin. We believe this method significantly contributes to determining the origin of paper mulberry bast fiber and handmade paper manufactured in East Asia.

Mineralogical-geochemical features of black shales from the frame of the Yayu igneous complex, Polar Urals

The results of study of mineralogical-geochemical features of black shales from the frame of the Yayu igneous complex (Polar Urals) are presented on the basis of modern analytical methods in order to identify possible mobilization, redeposition and concentration of ore material during intensive hydrothermal alteration. The high contents of Li, Be, Ba, Ti, Mn, Zr, Rb, Sc, Cs, P, Nb, Ta, Th, and REE are revealed. Rare metal and rare-earth minerals and a silver mineral (most likely, hessite) are found, the presence of alluvial gold in alluvium is established. The metallogenic features of carbonaceous sedimentary rocks afected by hydrothermal processes at the contact zone with igneous rocks are determined. The conclusion is made on a possible fnding of primary gold related to hydrothermal mineralisation in black shale of the region.