Muirhead mean (MM) is a well-known aggregation operator which can consider interrelationships among any number of arguments assigned by a variable vector. Besides, it is a universal operator since it ...can contain other general operators by assigning some special parameter values. However, the MM can only process the crisp numbers. Inspired by the MM' advantages, the aim of this paper is to extend MM to process the intuitionistic fuzzy numbers (IFNs) and then to solve the multi-attribute group decision making (MAGDM) problems. Firstly, we develop some intuitionistic fuzzy Muirhead mean (IFMM) operators by extending MM to intuitionistic fuzzy information. Then, we prove some properties and discuss some special cases with respect to the parameter vector. Moreover, we present two new methods to deal with MAGDM problems with the intuitionistic fuzzy information based on the proposed MM operators. Finally, we verify the validity and reliability of our methods by using an application example, and analyze the advantages of our methods by comparing with other existing methods.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Numerous skarn-type Sn deposits have been identified in the Nanling Range (South China), of which the Shizhuyuan W-Sn-Bi-Mo, Xianghualing Sn, Jinchuantang Sn-Bi, and Hehuaping Sn deposits are the ...largest. The Xianghualing deposit, which is the focus of this study, hosts a resource of 0.17 Mt Sn grading 0.93-1.39 wt% SnO2. Whether the distal skarn-type mineralization and the cassiteritesulfide vein-type orebody in the Xianghualing district are genetically related to the Laiziling granitic pluton, which produced the proximal skarn-type Sn mineralization, however, is still unknown. The Xianghualing Sn mineralization occurs exclusively as cassiterite and has been subdivided into four ore-types: (1) lenticular proximal skarn ore (Cst I) containing the mineral assemblage cassiteritepyrrhotite-chalcopyrite-actinolite-wollastonite; (2) layered distal skarn ore (Cst II) containing the mineral assemblage cassiterite-pyrrhotite-chalcopyrite-actinolite; (3) vein cassiterite-sulfide ore (Cst III) distal from the skarn and associated granite containing the mineral assemblage cassiterite-arsenopyrite-pyrrhotite-muscovite-fluorite; and (4) veinlet Sn-Pb-Zn ore (Cst IV) distal from the skarn and associated granite containing the mineral assemblage cassiterite-galena-sphalerite-topaz-quartz. Here, we report the results of in situ laser ablation inductively coupled plasma mass spectrometric (LA-ICPMS) U-Pb age determinations for garnet from the Xianghualing skarn and the above four types of cassiterite. Our age determinations indicate that there were two independent magmatic-hydrothermal events at ∼160 and 156∼150 Ma, both of which led to Sn mineralization. The first Sn mineralization event at DF160 Ma (Cst IV U-Pb ages of 159.6 ± 1.4 to 158.5 ± 0.8 Ma) is interpreted to have been associated with a speculative unexposed granitic pluton, which is coeval with the nearby Jianfengling granite intrusion. The second Sn mineralization event at 156∼150 Ma (Cst I to Cst III U-Pb ages of 155.9 ± 0.7 to 152.3 ± 1.1 Ma and garnet U-Pb ages of 153.6 ± 7.6 to 151.5 ± 3.5 Ma) is genetically related to the adjacent Laiziling granitic intrusion (152.8 ± 1.2 Ma, zircon U-Pb age). This event was responsible for the bulk of the Sn resource (>95%). Our age determinations provide convincing evidence for superimposed Jurassic Sn mineralizing systems at Xianghualing. They also show the value of combining garnet and cassiterite U-Pb age determinations to constrain the timing of skarn and Sn mineralization and distinguish discrete Sn mineralizing events in a protracted metallogenic history.
The origin of stratabound deposits in the Middle-Lower Yangtze River Valley Metallogenic Belt (MLYRB), Eastern China, is the subject of considerable debate. The Xinqiao Cu-Fe-Au deposit in the ...Tongling ore district is a typical stratabound ore body characterized by multi-stage magnetite. A total of six generations of magnetite have been identified. Mt1 is commonly replaced by porous Mt2, and both are commonly trapped in the core of Mt3, which is characterized by both core-rim textures and oscillatory zoning. Porous Mt4 commonly truncates the oscillatory zoning of Mt3, and Mt5 is characterized by 120° triple junction texture. Mt1 to Mt5 are commonly replaced by pyrite that coexists with quartz, whereas Mt6, with a fine-grained foliated and needle-like texture, commonly cuts the early pyrite as veins and is replaced by pyrite that coexists with calcite. The geochemistry of the magnetite suggests that they are hydrothermal in origin. The microporosity of Mt2 and Mt4 magnetite, their sharp contacts with Mt1 and Mt3, and lower trace-element contents (e.g., Si, Ca, Mg, and Ti) than Mt1 and Mt3 suggest that they formed via coupled dissolution and reprecipitation of the precursor Mt1 and Mt3 magnetite, respectively. This was likely caused by high-salinity fluids derived from intensive water-rock interaction between the magmatic-hydrothermal fluids associated with the Jitou stock and Late Permian metalliferous black shales. The 120° triple junction texture of Mt5 suggests it is the result of fluid-assisted recrystallization, whereas Mt6 formed by replacement of hematite as a result of fracturing. The geochemistry of the magnetite suggests that the temperature increased from Mt2 to Mt3 and implies that there were multiple pulses of fluids from a magmatic-hydrothermal system. Therefore, we propose that the Xinqiao stratiform mineralization was genetically associated with multiple influxes of magmatic hydrothermal fluids derived from the Early Cretaceous Jitou stock. This study demonstrates that detailed texture examination and in situ trace-elements analysis under robust geological and petrographic frameworks can effectively constrain the mineralization processes and ore genesis.
Breast cancer is the most common malignancy in women all over the world. MiRNAs are a type of small noncoding RNA that can regulate various cellular processes via binding different target genes in ...cancer cells. In this study, we found that miR-128-3p could suppress cellular proliferation and motility abilities of breast cancer. In addition, we found that overexpression of miR-128-3p arrested breast cancer cells in G0/G1 phase by affecting expression of CDK4/CDK6/Cyclin D1 and CDK2/Cyclin E1. Furthermore, we confirmed that LIM domain kinase 1 (LIMK1) is a direct target gene of miR-128-3p and that overexpression of miR-128-3p could suppress the expression levels of LIMK1 and Cofilin 1, which is downstream of LIMK1. TCGA clinical database showed that miR-128-3p was highly expressed in breast cancer patients and that high expression of miR-128-3p indicates a better prognosis of breast cancer. Our findings demonstrated that miR-128-3p could regulate cellular progression of breast cancer via regulating the LIMK1/CFL1 signaling pathway, and this new avenue could broaden existing versions of molecular mechanisms in breast cancer and perhaps represent potential novel direction of breast cancer treatment in the future.
White‐light emissive materials are gaining increasing attentions, ascribed to the potential applications in display and lighting devices as well as sensors. The realization of white‐light emission ...demands either the simultaneous emission of red, green, and blue colors or at least two complementary colors with similar distribution of emission intensities covering the entire visible spectrum. The introduction of supramolecular approaches not only relieves the negative effects of intermolecular interactions and energy transfer processes, but also endows the white‐light emissive materials with the capacity of color tunability and stimuli‐responsiveness, due to the dynamic and reversible nature of noncovalent interactions. Supramolecular materials with well‐ordered structures can regulate the energy transfer by the assembly–disassembly process, and meanwhile bring in extra fascinating attributes. This review mainly describes the recent reports on fabricating white‐light‐emitting materials from supramolecular approaches such as hydrogen bonding, host–guest interaction, π–π stacking, and metal coordination, which enriches the conceptions and pathways to afford such materials. Moreover, some perspectives together with pressing challenges are presented in the end, synchronously forecasting the potential trends of white‐light emissive materials.
This review summarizes the recent reports on fabricating white‐light‐emitting materials from supramolecular approaches such as hydrogen bonding, host–guest interaction, π–π stacking, and metal coordination, which enriches the concepts and pathways to enable such materials. Moreover, some perspectives together with pressing challenges are presented in the end, synchronously forecasting the potential trends of white‐light emissive materials.
Rare earth elements (REE) and yttrium (Y), termed as REY, are recently found to be extremely enriched in some pelagic sediments, which could be an important resource for REY in the future. However, ...their enrichment mechanism remains controversial. Because biogenetic apatite is one of the most important REY carriers in REY-rich deep-sea sediment, it is critical to identify its mineralogical and geochemical characteristics by using combined methods of in situ chemical analysis and atomic resolution chemical imaging.
Scanning electron microscope and transmission electron microscopy studies reveal that bioapatite fossils mainly consist of aligned hydroxyapatite nano-plates. Laser ablation-inductively coupled plasma-mass spectrometry analyses show that the REY are not uniformly distributed within the studied bioapatite fossils. Concentration profiles from the measurements and modeling analyses indicate that the major REY should be incorporated into the bioapatite fossil from seawater as well as the pore water during the early stage of diagenesis. Z-contrast imaging results reveal the following two possible coupled substitutions in the apatite: REE3+ + Na+ ↔ 2Ca2+ and/or REE3+ + Si4+ ↔ Ca2+ + P5+, which is distinguished from those ion-absorption-type REE deposits on land. Our study indicates that bioapatite fossils are prone to undergo alteration during diagenesis, and thus cautious examination should be taken when applying REE signal of bioapatite as a proxy for palaeo-ocean environmental reconstruction.
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•Z-contrast was used to image substituted REY of bioapatite in atomic resolution.•The extraction of REY in the REY-rich deep-sea sediment needs strong acid.•Bioapatite obtains REE from seawater and/or pore water during early diagenesis.•Histology controls the REE in-diffusion pathway within bioapatite fossils.•Cautious examination is required for using REE signals in bioapatite for palaeoceanographic study.
Marine ferromanganese crusts are considered to be the potential Pt deposits, and recent studies report a strong association between Pt and vernadite in these crusts. However, there are still ...uncertainties regarding the molecular processes involved in the enrichment of Pt by vernadite. This study investigates the adsorption behavior and molecular-scale immobilization mechanisms of Pt at water/vernadite interfaces through a combination of batch adsorption and desorption experiments, X-ray absorption fine structure (XAFS) analyses, and atomic resolution chemical imaging. Our findings suggest that the Pt enrichment on vernadite is attributed to an isomorphic substitution of Mn by Pt. The extended X-ray absorption fine structure (EXAFS) analysis reveals that Pt undergoes ligand exchange reactions during the enrichment process, and provides a comprehensive explanation of how Pt penetrates into the vernadite structure starting from the surface. Scanning transmission electron microscopy high-angle annular dark field (STEM-HAADF) observations visually confirm the infiltration of Pt atoms into the crystal structure of vernadite. Additionally, we demonstrate that the Pt enrichment in vernadite is a multi-stage chemical process. X-ray absorption near edge structure (XANES) analysis shows that Pt is initially rapidly adsorbed onto the surface of vernadite and then slowly oxidized. Our study provides a detailed understanding of the molecular-scale mechanisms involved in the adsorption of Pt onto vernadite and its subsequent structural incorporation. This knowledge is valuable for gaining insights into the Pt enrichment in marine ferromanganese crusts.
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•XANES analysis shows that Pt is initially rapidly adsorbed onto the surface of vernadite and then slowly oxidized.•EXAFS analysis provides an explanation of how Pt penetrates into the vernadite structure starting from the surface.•STEM-HAADF observations visually confirm the infiltration of Pt atoms into the crystal structure of vernadite.
The search for topological semimetals is mainly focused on heavy-element compounds by following the footsteps of previous research on topological insulators, with less attention on light-element ...materials. However, the negligible spin orbit coupling with light elements may turn out to be beneficial for realizing topological band features. Here, using first-principles calculations, we propose a new two-dimensional light-element material-the honeycomb borophene oxide (h-B2O), which has nontrivial topological properties. The proposed structure is based on the recently synthesized honeycomb borophene on an Al (111) substrate W. Li, L. Kong, C. Chen, J. Gou, S. Sheng, W. Zhang, H. Li, L. Chen, P. Cheng and K. Wu, Sci. Bull., 2018, 63, 282-286. The h-B2O monolayer is completely flat, unlike the oxides of graphene or silicene. We systematically investigate the structural properties of h-B2O, and find that it has very good stability and exhibits significant mechanical anisotropy. Interestingly, the electronic band structure of h-B2O hosts a nodal loop centered around the Y point in the Brillouin zone, protected by the mirror symmetry. Furthermore, under moderate lattice strain, the single nodal loop can be transformed into two loops, each penetrating through the Brillouin zone. The loops before and after the transition are characterized by different Doublestruck Z × Doublestruck Z topological indices. Our work not only predicts a new two-dimensional material with interesting physical properties, but also offers an alternative approach to search for new topological phases in 2D light-element systems.
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