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Time-resolved, defect-hosted, trace element mobility in deformedWitwatersrand pyrite

Geoscience Frontiers 2019年第1期10卷 55-63页

作者： Denis Fougerouse Steven m.Reddy Christopher L.Kirkland David W.Saxey william D.Rickard Robert m.Hough School of Earth and Planetary Sciences The Institute for Geoscience Research (TIGeR) Curtin University Geoscience Atom Probe Advanced Resource Characterisation Facility John de Laeter Centre Curtin University CSIRO minerals Resources

The Pb isotopic composition of rocks is widely used to constrain the sources and mobility of melts and hydrothermal fluids in the Earth's crust. In many cases, the Pb isotopic composition appears to represent mixing of multiple Pb reservoirs. However, the nature, scale and mechanisms responsible for isotopic mixing are not well known. Additionally, the trace element composition of sulphide minerals are routinely used in ore deposit research, mineral exploration and environmental studies, though little is known about element mobility in sulphides during metamorphism and deformation. To investigate the mechanisms of trace element mobility in a deformed Witwatersrand pyrite(FeS_2), we have combined electron backscatter diffraction(EBSD) and atom probe microscopy(APm). The results indicate that the pyrite microstructural features record widely different Pb isotopic compositions, covering the entire range of previously published sulphide Pb compositions from the Witwatersrand basin. We show that entangled dislocations record enhanced Pb, Sb, Ni, Tl and Cu composition likely due to entrapment and short-circuit diffusion in dislocation cores. These dislocations preserve the Pb isotopic composition of the pyrite at the time of growth(~3 Ga) and show that dislocation intersections, likely to be common in deforming minerals, limit trace element mobility. In contrast, Pb, As, Ni, Co, Sb and Bi decorate a highangle grain boundary which formed soon after crystallisation by sub-grain rotation *** isotopic composition within this boundary indicates the addition of externally-derived Pb and trace elements during greenschist metamorphism at ~2 Ga. Our results show that discrete Pb reservoirs are nanometric in scale, and illustrate that grain boundaries may remain open systems for trace element mobility over 1 billion years after their formation.

关键词： Atom probe microscopy Nanoscale Nanogeochronology microstructure Isotope geochemistry Common Pb

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The evolving ENSO observing system

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National Science Review 2018年第6期5卷 805-807页

作者： Dake Chen Neville Smith william Kessler State Key Laboratory of Satellite Ocean Environment Dynamics Second Institute of Oceanography

El Nio–Southern Oscillation (ENSO)is by far the most energetic and influential short-term climate variability on our planet, originating from an instability of the large-scale ocean-atmosphere interaction in the tr... 详细信息

关键词： The evolving ENSO observing system TAO

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Linking uplift and mineralisation at the mount Novit Zn-Pb-Ag Deposit,Northern Australia:Evidence from geology,U-Pb geochronology and sphalerite geochemistry

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Geoscience Frontiers 2022年第2期13卷 333-350页

作者： Bradley Cave william Perkins Richard Lilly Department of Earth Sciences University of AdelaideAdelaideSAAustralia Geological Survey of Queensland BrisbaneQLDAustralia

The subeconomic mount Novit Zn-Pb-Ag deposit is located approximately 20 km south of mount Isa,*** contrast to the nearby mount Isa,Hilton and George Fisher Zn-Pb-Ag deposits,mineralisation at mount Novit is situated to the west of the regional-scale mount Isa Fault and is hosted in the moondarra Siltstone as opposed to the Urquhart ***-grade(mineralisation primarily replaces pre-existing carbonate alteration and veining and consists of pyrrhotite,pyrite and sphalerite with lesser ***-grade(>10 wt.%Zn+Pb)mineralisation occurs as a matrix supported breccia dominated by sphalerite and pyrrhotite with galena,pyrite,and ***-situ U-Pb geochronology was completed on apatite and two textural varieties of ***-grained(m)subhedral to anhedral monazite is located within highly foliated biotite alteration directly adjacent Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1527±18 ma(mSWD=1.06).This age is consistent with the formation of highly foliated biotite alteration during D;deformation of the Isan *** from the same fabric yields a lower intercept age of1443±29 ma(mSWD=1.30).Consistent with previous studies,this age is interpreted to represent the age of a major thrusting event along the mount Isa Fault that resulted in the cooling of the mount Novit area below~375℃.Coarse-grained monazite is coeval with Zn-Pb-Ag mineralisation and yields a mean weighted^(207)Pb/^(206)Pb age of 1457±11 ma(mSWD=0.28).Sphalerite from mount Novit has low concentrations(m)of Ge and Ga and a relatively high concentration of In(5 to>10 ppm),possibly reflecting the leaching of the metals from an underlying basement *** GGImFis geothermometer(Frenzel et al.,2016)produced a mean formation temperature of 345±52℃.The timing and temperature of Zn-Pb-Ag mineralisation is consistent with the age and cooling temperature of apatite presented in this *** on these correlations,we

关键词： mount Isa mount Novit Zn-Pb-Ag mineralisation monazite Apatite Geochronology

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Environmental drivers and genomic architecture of trait differentiation in fire-adapted Banksia attenuata ecotypes

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Journal of Integrative Plant Biology 2019年第4期61卷 417-432页

作者： Tianhua He Byron B.Lamont Neal J.Enright Haylee m.D'Agui william Stock School of molecular and Life Sciences Curtin University School of Veterinary and Life Sciences Murdoch University Centre for Ecosystem management Edith Cowan University

Trait divergence between populations is considered an adaptive response to different environments,but to what extent this response is accompanied by genetic differentiation is less clear since it may be phenotypic plasticity. In this study, we analyzed phenotypic variation between two Banksia attenuata growth forms, lignotuberous(shrub) and epicormic resprouting(tree), in fire-prone environments to identify the environmental factors that have driven this phenotypic divergence. We linked genotype with phenotype and traced candidate genes using differential gene expression analysis. Fire intervals determined the phenotypic divergence between growth forms in B. attenuata. A genome-wide association study identified 69 single nucleotide polymorphisms, putatively associated with growth form, whereas no growth form-or phenotype-specific genotypes were eidentified. Genomic differentiation between the two growth forms was low(F_(st)=0.024). Differential gene expression analysis identified 37 genes/transcripts that were differentially expressed in the two growth forms. A small heat-shock protein gene, associated with lignotuber presence, was differentially expressed in the two *** conclude that different fire regimes induce phenotypic polymorphism in B. attenuata, whereas phenotypic trait divergence involves the differential expression of a small fraction of genes that interact strongly with the disturbance regime. Thus, phenotypic plasticity among resprouters is the general strategy for surviving varying fire regimes.

关键词： Environmental drivers genomic architecture trait differentiation

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Seed value influences cache pilfering rates by desert rodents

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Integrative Zoology 2019年第1期14卷 75-86页

作者： Stephen B.VANDER WALL Lindsay A.DImITRI william S.LONGLAND Joseph D.m.WHITE Department of Biology and Program in Ecology Evolution and Conservation BiologyUniversity of NevadaRenoUSA USDA Agricultural Research ServiceRenoNevadaUSA Department of Biological Sciences University of Cape TownCape TownRepublic of South Africa

Some rodents gather and store *** many seeds they gather and how they treat those seeds is largely determined by seed traits such as mass,nutrient content,hardness of the seed coat,presence of secondary compounds,and germination *** their consumption and dispersal of seeds,rodents act as agents of natural selection on seed traits,and those traits influence how rodents *** seeds that are scatter-hoarded by rodents are pilfered,or stolen,by other rodents,and seed traits also likely influence pilfering rates and seed fates of pilfered *** clarify coevolutionary relationships between rodents and the plants that they disperse,one needs to understand the role of seed traits in rodent foraging *** compared how the seeds of 4 species of plants that are dispersed by scatter-hoarding animals and that differ in value(singleleaf piñon pine,Pinus monophylla;desert peach,Prunus andersonii;antelope bitterbrush,Purshia tridentata;Utah juniper,Juniperus osteosperma)were pilfered and recached by *** hundred artificial caches of the 4 seed species(25 per species)were prepared,and removal by rodents was *** pilfered high-value seeds more rapidly than the other *** peach seeds,which contain toxic secondary compounds,were more frequently *** low value seeds like Utah juniper and antelope bitterbrush were pil-fered more slowly and were sometimes left at cache sites,and seeds of the latter species were transported shorter distances to new cache *** background density of seeds also appeared to influence the relative value of seeds.

关键词： desert rodents food storage granivory pilfering scatter-hoarding seed dispersal seed traits

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Differential Privacy via a Truncated and Normalized Laplace mechanism

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Journal of Computer Science & Technology 2022年第2期37卷 369-388页

作者： william Croft Jorg-Rudiger Sack Wei Shi School of Computer Science Carleton UniversityOttawa K1S 5B6Canada School of Information Technology Carleton UniversityOttawa K1S 5B6Canada

When querying databases containing sensitive information,the privacy of individuals stored in the database has to be *** guarantees are provided by differentially private mechanisms which add controlled noise to the query ***,most such mechanisms do not take into consideration the valid range of the query being ***,noisy responses that fall outside of this range may potentially be *** rectify this and therefore improve the utility of the mechanism,the commonly-used Laplace distribution can be truncated to the valid range of the query and then ***,such a data-dependent operation of normalization leaks additional information about the true query response,thereby violating the differential privacy ***,we propose a new method which preserves the differential privacy guarantee through a careful determination of an appropriate scaling parameter for the Laplace *** adapt the privacy guarantee in the context of the Laplace distribution to account for data-dependent normalization factors and study this guarantee for different classes of range constraint *** provide derivations of the optimal scaling parameter(i.e.,the minimal value that preserves differential privacy)for each class or provide an approximation *** a result of this work,one can use the Laplace distribution to answer queries in a range-adherent and differentially private *** demonstrate the benefits of our proposed method of normalization,we present an experimental comparison against other range-adherent *** show that our proposed approach is able to provide improved utility over the alternative mechanisms.

关键词： differential privacy Laplace mechanism query range constraint

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Continuous conversion of methanol to higher hydrocarbons at ambient pressure

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Journal of Natural Gas Chemistry 2010年第5期19卷 461-462页

作者： william W.Porterfield Gordon m.Zrelak L.Avery moncure matthew D.Huff Hampden-Sydney College Pennsylvania State University University Park UNC-Charlotte

An iodozincate ionic liquid solvent and catalyst is used to convert methanol continuously to a wide variety of hydrocarbons at atmospheric pressure.

关键词： methanol conversion zinc iodide hydrocarbon formation

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Solution‑Processed Thin Film Transparent Photovoltaics:Present Challenges and Future Development

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Nano-micro Letters 2025年第2期17卷 566-600页

作者： Tianle Liu munerah m.S.Almutairi Jie ma Aisling Stewart Zhaohui Xing mengxia Liu Bo Hou Yuljae Cho Um-SJTU Joint Institute Shanghai Jiao Tong UniversityShanghai 200240People’s Republic of China School of Physics and Astronomy Cardiff UniversityCardiff CF243AAWalesUK Department of Electrical and Computer Engineering Yale UniversityNew HavenCT 06511USA Energy Sciences Institute Yale UniversityWest HavenCT 06516USA Future Photovoltaics Research Center Global Institute of Future TechnologyShanghai Jiao Tong UniversityShanghai 200240People’s Republic of China

Electrical energy is essential for modern society to sustain economic *** soaring demand for the electrical energy,together with an awareness of the environmental impact of fossil fuels,has been driving a shift towards the utilization of solar ***,traditional solar energy solutions often require extensive spaces for a panel installation,limiting their practicality in a dense urban *** overcome the spatial constraint,researchers have developed transparent photovoltaics(TPV),enabling windows and facades in vehicles and buildings to generate electric *** TPV advancements are focused on improving both transparency and power output to rival commercially available silicon solar *** this review,we first briefly introduce wavelength-and non-wavelengthselective strategies to achieve *** of merit and theoretical limits of TPVs are discussed to comprehensively understand the status of current TPV *** we highlight recent progress in different types of TPVs,with a particular focus on solution-processed thin-film photovoltaics(PVs),including colloidal quantum dot PVs,metal halide perovskite PVs and organic *** applications of TPVs are also reviewed,with emphasis on agrivoltaics,smart windows and ***,current challenges and future opportunities in TPV research are pointed out.

关键词： Transparent semiconductors Solution-processable transparent solar cell Emerging solar cell materials Buildingintegrated photovoltaics

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Implications of membrane fouling toward the removal of the pharmaceutical sulfamethoxazole by nanofiltration processes

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第8期12卷 575-582页

作者： Alexander SImON william PRICE Long Duc NGHIEm School of Civil mining and Environmental Engineering the University of Wollongong School of Chemistry the University of Wollongong

The influence of membrane fouling on the retention of the trace organic contaminant sulfamethoxazole by a nanofiltration(NF) process was *** fouling caused a severe flux decline possibly due to pore blocking and adsorption directly after the commencement of the fouling layer *** membrane-foulant interactions were absent for colloidal fouling,which resulted in a more gradual flux *** charge played a significant role in the separation process of inorganic salts,where the retention was the highest in a caustic environment(high pH) due to more swollen membrane material caused by the higher negative charge on the *** fouling and a combination of colloidal and organic fouling led to a significant increase in the membrane negative *** influence of membrane fouling on solute retention was dependent on the fouling behaviour and the physicochemical properties of the model foulants,where the model foulants probably contributed to an increase in the retention of charged solutes due to enhanced electrostatic *** fouling caused an increase in the retention of inorganic salts and sulfamethoxazole due to pore *** contrast,colloidal fouling caused a decrease in the retention of inorganic salts due to cake-enhanced concentration ***,the presence of a colloidal fouling layer did not reduce the retention of sulfamethoxazole.A mixture of colloidal and organic matter improved the retention of inorganic salts.A similar conclusion can be inferred for sulfamethoxazole at pH 4 when the compound exists in a neutral form.

关键词： Nanofiltration(NF) Organic fouling Colloidal fouling Combined fouling Trace organics Water reuse

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A two scale nonlinear fractal sea surface model in a one dimensional deep sea

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Chinese Physics B 2010年第5期19卷 607-612页

作者：谢涛邹光辉 william Perrie 旷海兰陈伟 School of Information Engineering of Wuhan University of Technology Fisheries and Oceans Canada Bedford Institute of OceanographyB2Y 4A2DartmouthNSCanada

Using the theory of nonlinear interactions between long and short waves, a nonlinear fractal sea surface model is presented for a one dimensional deep sea. Numerical simulation results show that spectra intensity changes at different locations （in both the wave number domain and temporal-frequency domain）, and the system obeys the energy conservation principle. Finally, a method to limit the fractal parameters is also presented to ensure that the model system does not become ill-posed,

关键词： fractal sea surface models nonlinear interaction numerical method

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