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Source to sink zircon grain shape:constraints on selective preservation and significance for Western Australian Proterozoic basin provenance

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Geoscience Frontiers 2018年第2期9卷 415-430页

作者： V.Markwitz c.l.Kirkland School of Earth ■ Environment The University of Western Australia department of Applied Geology Centre for Exploration Targeting-Curtin NodeJohn de Laeter CentreInstitute of Geoscience Research (TIGeR)Curtin University

The effect of selective preservation during transportation of zircon grains on the detrital age spectrum is difficult to quantify and could potentially lead to systematic bias in provenance analysis. Here we investigate whether the shape of detrital zircon grains holds provenance information and if the grain shape can assist in understanding preservation. We applied multiple linear regression analysis to identify significant shape properties in detrital zircons from Proterozoic metasediments of the capricorn and Amadeus basins and their Archean and Proterozoic sources in the Yilgarn craton and the Musgrave Province in Western Australia. Digital images and isotopic data from 819 SIMS U-Pb dated zircons were examined for correlation between grain shape, age, U and Th content. Out of twelve shape descriptors measured, Minor Axis, the width of zircon grains perpendicular to the crystallographic c-axis, consistently shows the most significant correlation with isotopic age. In the studied population Archean grains are narrower than Proterozoic grains: the probability that grains wider than 75 μm are Archean is less than30%.calculations of the proportions of source material in sedimentary rocks relative to the proportions of source material in the overall catchment area(erosion parameter 'K' calculated based on age spectra)produced values typical for mature river systems, with K = 6 for the Yilgarn-capricorn and K = 5.5 for the Musgrave-Amadeus source-sink system. For the Yilgarn-capricorn system, we also calculated 'K' based on Minor Axis, to determine whether grain width can be linked to age populations. Results of the shapebased K of 5.3 suggest a similarity between age-based and shape-based 'K' values, demonstrating that zircon grain width may be a useful discriminator of provenance. contrary to commonly applied qualitative shape classifications, we found no consistent correlations between shape descriptors of magmatic zircons and the composition of their host rock. Wh

关键词： Zircon grain shape U-Pb geochronology detrital Whole rock geochemistry Precambrian

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On the Role of Differentiation Parameter in a Bound State Solution of the Klein-Gordon Equation

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communications in Theoretical Physics 2019年第3期71卷 267-273页

作者： B.c.lütfüo?lu department of Physics Faculty of Science Akdeniz University department of Physics Faculty of Science University of Hradec Králové

Recently, the bound state solutions of a confined Klein-Gordon particle under the mixed scalar-vector generalized symmetric Woods-Saxon potential in one spatial dimension have been investigated. The obtained results reveal that in the spin symmetric limit discrete spectrum exists, while in the pseudo-spin symmetric limit it does *** this manuscript, new insights and information are given by employing an analogy of the variational principle. The role of the difference of the magnitudes of the vector and scalar potential energies, namely the differentiation parameter,on the energy spectrum is examined. It is observed that the differentiation parameter determines the measure of the energy spectrum density by modifying the confined particle's mass-energy in addition to narrowing the spectrum interval length.

关键词： Klein-Gordon equation generalized symmetric Woods-Saxon potential bound st ate spectrum spin symmetry limit analytic solutions

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coercivity mechanisms in nanostructured permanent magnets

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chinese Physics B 2019年第7期28卷 1-13页

作者： G P Zhao l Zhao l c Shen J Zou l Qiu college of Physics and Electronic Engineering & Institute of Solid State Physics Sichuan Normal UniversityChengdu 610066 China State Key luboratory of Metastablc Materials Science and Technology Yunshnn University.Qinhuangdao 066004China collaborative Innovation center for Shunxi Advanced Permanent Materials and Technology Lint'en 041004 China

coercivity mechanism in permanent magnets has been debated for many *** this paper, various models of the coercivity mechanism are classified and re-examined by the comparison and *** rotation and curling models can reveal the underlying reversal mechanism clearly based on isolated grains with elliptic *** contrast, the numerical methods consider inter-grain interactions while simulating the evolution of the spins and hysteresis loops with complicated ***, an exact simulation of magnetic reversal in permanent nanomagnets requires many meshes to mimic the thin domain wall *** and pinning are the two main coercivity mechanisms in permanent *** former signifies the beginning of the magnetic reversal, whilst the latter completes ***, it is proposed that the large difference between the intrinsic magnetic properties of the nucleation centers and those of the main phase can result in a large pinning field(self-pinning), which has the attributes of both traditional nucleation and *** a pinning explains the experimental data of permanent magnets very well, including the enhancement of the coercivity by the grain boundary pinning.

关键词： coercivity mechanism permanent nanomagnets self-pinning

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Extracellular vesicles as a potential therapeutic for age-related macular degeneration

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Neural Regeneration Research 2023年第9期18卷 1876-1880页

作者： lorraine l.c.chow Ben Mead School of Optometry and Vision Sciences Cardiff UniversityCardiffUK

Age-related macular degeneration is a major global cause of central visual impairment and seve re vision *** an aging population,the already immense economic burden of costly anti-vascular endothelial growth fa ctor treatment is likely to *** addition,current conventional treatment is only available for the late neovascular stage of age-related macular degeneration,and injections can come with potentially devastating complications,introducing the need for more economical and ris kfree *** recent years,exosomes,which are nano-sized extracellular vesicles of an endocytic origin,have shown immense potential as diagnostic biomarkers and in the therapeutic application,as they are bestowed with characte ristics including an expansive cargo that closely resembles their parent cell and exceptional ability of intercellular communication and targeting neighboring *** are currently undergoing clinical trials for various conditions such as type 1 diabetes and autoimmune diseases;however,exosomes as a potential therapy for seve ral retinal diseases have just begun to undergo scrutinizing investigation with little literature on age-related macular degeneration *** article will focus on the limited literature availa ble on exosome transplantation treatment in age-related macular degeneration animal models and in vitro cell cultures,as well as briefly identify future research *** literature on exosome therapy using agerelated macular degeneration rodent models includes laser retinal injury,N-methyl-N-nitrosourea,and royal college of surgeon models,which mimic inflammatory and degenerative aspects of agerelated macular *** have shown promising results in preserving retinal function and morphology,as well as protecting photoreceptors from *** from their respective cellular origins may also act by regulating the expression of various inflammatory cyto kines,mRNAs,and proteins involved in photo

关键词： age-related macular degeneration exosomes extracellular vesicles miRNA neuroprotection photoreceptors retina retinal pigment epithelium

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Structure Investigation of Poly(vinyl alcohol)-collagen composite

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Journal of Materials Science & Technology 1997年第3期13卷 179-183页

作者： Zhang, QQ Ren, l liu, lR Wang, c UNIV UTAH CCCDSALT LAKE CITYUT 84112

Naturally derived collagen protein was mixed thoroughly with medical grade poly (vinyl alcohol) (PVA) at the ratio of 90:10 (w/w) and was crosslinked by formaldehyde to form a homogeneous composite membrane. The bulk structure of the membrane was characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The membrane surface structure was investigated using Fourier transform-infrared spectroscopy (attenuated total refraction) (FTIR-ATR), electron spectroscopy for chemical analysis (EScA) and contact angle measurement. It was found that collagen and PVA can remain stable. This was supported by the fact that no sign of phase separation had been observed. The use of crosslinking agent can substantially influence the structure of the composite. It is suggested that this new composite deserves further investigation and is potentially usable as a biomedical material.

关键词： Nonmetallic matrix composites

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chaos Suppression in a Sine Square Map through Nonlinear coupling

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chinese Physics letters 2011年第11期28卷 45-48页

作者： Eduardo l.Brugnago Paulo c.Rech departamento de Física Universidade do Estado de Santa Catarina89223-100 JoinvilleBrazil

We study a pair of nonlinearly coupled identical chaotic sine square *** specifically,we investigate the chaos suppression associated with the variation of two ***-dimensional parameter-space regions where the chaotic dynamics of the individual chaotic sine square map is driven towards regular dynamics are ***,the dynamics of the coupled system is numerically characterized as the parameters are changed.

关键词： chaotic dynamics chaos

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Performance analysis of fuzzy BlS using different cluster methods for classification

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Science china(Information Sciences) 2021年第4期64卷 232-234页

作者： Shuang FENG c.l.Philip cHEN School of Applied Mathematics Beijing Normal University Faculty of Science and Technology University of Macau

dear editor,Neural networks (NNs) and fuzzy systems are commonly used computational intelligence techniques, each with their own merits in terms of applications. The integration of NNs and fuzzy systems, which leads to a hybrid framework known as neuro-fuzzy systems, inherits the useful properties of its constituents:the learning power of an NN and the knowledge representation of a fuzzy inference system,

关键词： Information Systems and communication Service

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SEMI-TIERED HOUSING FOR lATERITE EARTH SlOPING lANDS-A SUSTAINABlE SOlUTION WITH AlTERNATIVE MATERIAlS AND METHODS

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Journal of Green Building 2018年第1期13卷 56-72页

作者： M.T.R.Jayasinghe c.Jayasinghe K.K.G.K.D.Kariyawasam l.I.N.de Silva department of civil Engineering University of Moratuwa-Sri Lanka University of Moratuwa-Sri lanka

Increased demand for affordable housing and the limited availability of flat terrain for its construction are two major problems facing the provision of houses of acceptable quality in many countries around the *** is limited research integrating the utilization of a stepped approach to sloping terrain with appropriate housing models to minimize slope instability *** paper introduces a new semi-tiered housing model where the footprint of the house is located on tiers prepared with short vertical cuts of *** vertical cuts are found to be stable with laterite soil which is a commonly available type of soil in the *** excess soil generated from cut material was transformed into cement stabilized rammed earth,which is a cost effective material with low embodied *** is an ideal candidate for the construction of retaining walls and foundations,and such applications are demonstrated with adequate ***,many other types of sustainable building materials are highlighted with a case study of this housing model in a scheme of 13 housing units in Sri *** attention to detail required in construction and the applicability of alternative building materials and methods to improve the sustainability of such houses have been discussed in *** semi-tiered houses have the potential to address many of the current construction challenges.

关键词： stepped housing stabilized earth micro concrete roofing tiles sustainable construction

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Growing Threat of Rapidly-Intensifying Tropical cyclones in East Asia

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Advances in Atmospheric Sciences 2022年第2期39卷 222-234页

作者： Kin Sik lIU Johnny c.l.cHAN Guy carpenter Asia-Pacific climate Impact centre School of Energy and EnvironmentCity University of Hong KongTat Chee Ave.KowloonHong KongChina

This study examines the long-term change in the threat of landfalling tropical cyclones(Tcs) in East Asia over the period 1975–2020 with a focus on rapidly intensifying(RI) Tcs. The increase in the annual number of RI-Tcs over the western North Pacific and the northwestward shift of their genesis location lead to an increasing trend in the annual number of landfalling RI-Tcs along the coast of East Asia. The annual power dissipation index(PDI), a measure of the destructive potential of RI-Tcs at landfall, also shows a significant increasing trend due to increases in the annual frequency and mean landfall intensity of landfalling RI-Tcs. The increase in mean landfall intensity is related to a higher lifetime maximum intensity(lMI) and the lMI location of the landfalling RI-Tcs being closer to the coast. The increase in the annual PDI of East Asia is mainly associated with landfalling Tcs in the southern(the Philippines, South china, and Vietnam) and northern parts(Japan and the Korean Peninsula) of East Asia due to long-term changes in vertical wind shear and Tc heat potential. The former leads to a northwestward shift of favorable environments for Tc genesis and intensification, resulting in the northwestward shift in the genesis, RI, and lMI locations of RI-Tcs. The latter provides more heat energy from the ocean for Tc intensification, increasing its chances to undergo RI.

关键词： tropical cyclone landfall tropical cyclone intensity climate change rapid intensification

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A stable cS-FEM for the static and seismic stability of a single square tunnel in the soil where the shear strength increases linearly with depth

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第4期14卷 1253-1265页

作者： H.c.Nguyen l.Nguyen-Son department of civil and Environmental Engineering Imperial College LondonLondonUK department of civil Engineering and Industrial design University of LiverpoolLiverpoolUK Faculty of civil Engineering Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh CityViet Nam

A numerical procedure using a stable cell-based smoothed finite element method(cS-FEM)is presented for estimation of stability of a square tunnel in the soil where the shear strength increases linearly with *** kinematically admissible displacement fields are approximated by uniform quadrilateral elements in conjunction with the strain smoothing technique,eliminating volumetric locking issues and the singularity associated with the Mohrecoulomb ***,a rich set of simulations was performed to compute the static stability of a square tunnel with different geometries and soil *** presented results are in excellent agreement with the upper and lower bound solutions using the standard finite element method(FEM).The stability charts and tables are given for practical use in the tunnel design,along with a newly proposed formulation for predicting the undrained stability of a single square ***,the seismic stability number was computed using the present numerical *** results reveal that the seismic stability number reduces with an increasing value of the horizontal seismic acceleration(a_(h)),for both cases of the weightless soil and the soil with unit ***,the link between the static and seismic stability numbers is described using corrective factors that represent reductions in the tunnel stability due to seismic *** is shown from the numerical results that the corrective factor becomes larger as the unit weight of soil mass increases;however,the degree of the reduction in seismic stability number tends to reduce for the case of the homogeneous ***,this advanced numerical procedure is straightforward to extend to three-dimensional(3D)limit analysis and is readily applicable for the calculation of the stability of tunnels in highly anisotropic and heterogeneous soils which are often encountered in practice.

关键词： Tunnels Stability limit analysis cell-based smoothed finite element method (cS-FEM) Second-order cone programming(SOcP)

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