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Journal of Materials science & Technology 2018年第1期34卷 92-101页

作者： Judy schneider Josef Cobb john s.carpenter Nathan A.Mara Department of Mechanical & Aerospace Engineering University of Alabama in Huntsville Department of Mechanical Engineering Mississippi State University Materials science and Technologies Division Los Alamos National Laboratory Center for Integrated Nanotechnologies and the Institute for Materials ScienceLos Alamos National Laboratory

Accumulative roll bonded （ARB） Copper Niobium （Cu-Nb） nano-lamellar composite （NLC） panels were friction stir welded （FsWed） to evaluate the ability to join panels while retaining the nano-lamellar structure. During a single pass of the friction stir welding （FsW） process, the nano-lamellar structure of the parent material （PM） was retained but was observed to fragment into equiaxed grains during the second pass. FsW has been modeled as a severe deformation process in which the material is subjected to an instantaneous high shear strain rate followed by extreme shear strains. The loss of the nano-lamellar layers was attributed to the increased strain and longer time at temperature resulting from the second pass of the FsW process. Kinematic modeling was used to predict the global average shear strain and shear strain rates experienced by the ARB material during the FsW process. The results of this study indicate that through careful selection of FsW parameters, the nano-lamellar structure and its associated higher strength can be maintained using FsW to join ARB NLC panels.

关键词： Nano-lamellar materials Accumulative roll bonded Cu-Nb FsW solid state joining

Hydrogen diffusion in clinopyroxene: dehydration experiments

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science China Earth sciences 2000年第6期43卷 561-568页

作者：夏群科陈道公 s.carpenter 支霞臣王汝成程昊 Department of Earth and space sciences University of Science and Technology of China Hefei 230026 China Department of Geosciences The Pennsylvania State University PA 16082 USA state Key Laboratory of Mineral Deposits Nanjing University Nanjing 210093 China

Hydrogen diffusivity of one clinopyroxene megacryst from Nüshan, eastern China parallel to [001]* crystallographic direction was measured by high-temperature sequential dehydration experiments at 950üC and 850üC, which was (6.5ü1.5)×10-12(m2/s) and (1.8×0.7)×10-12(m2/s) respectively. From these results and the previous published data, it seems that the correlation between hydrogen diffusivity and Fe content suggested by Dyar et al. (1996) possibly does not exist. Clinopyroxene megacrysts from alkali basalts appear to be possible reliable samples for the study of the water evolution and hydrogen isotope compositions of the upper mantle.

关键词： clinopyroxene hydrogen diffusion dehydration.

Targeting TrkB–PsD-95 coupling to mitigate neurological disorders

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Neural Regeneration Research 2025年第3期20卷 715-724页

作者： Xin Yang Yu-Wen Alvin Huang john Marshall Department of Molecular Biology Cell Biology and BiochemistryBrown UniversityProvidenceRIUSA Department of Neurology Warren Alpert Medical School of Brown UniversityProvidenceRIUSA Center for Translational Neuroscience Robert J.and Nancy D.Carney Institute for Brain Science and Brown Institute for Translational ScienceBrown UniversityProvidenceRIUSA

Tropomyosin receptor kinase B(TrkB)signaling plays a pivotal role in dendritic growth and dendritic spine formation to promote learning and *** activity-dependent release of brain-derived neurotrophic factor at synapses binds to pre-or postsynaptic TrkB resulting in the strengthening of synapses,reflected by long-term ***,the association of postsynaptic density protein-95 with TrkB enhances phospholipase Cγ-Ca^(2+)/calmodulin-dependent protein kinaseⅡand phosphatidylinositol 3-kinase-mechanistic target of rapamycin signaling required for long-term *** this review,we discuss TrkB-postsynaptic density protein-95 coupling as a promising strategy to magnify brain-derived neurotrophic factor signaling towards the development of novel therapeutics for specific neurological disorders.A reduction of TrkB signaling has been observed in neurodegenerative disorders,such as Alzheimer's disease and Huntington's disease,and enhancement of postsynaptic density protein-95 association with TrkB signaling could mitigate the observed deficiency of neuronal connectivity in schizophrenia and *** with brain-derived neurotrophic factor is problematic,due to poor pharmacokinetics,low brain penetration,and side effects resulting from activation of the p75 neurotrophin receptor or the truncated TrkB.T1 *** TrkB agonists and antibodies that activate TrkB are being intensively investigated,they cannot distinguish the multiple human TrkB splicing isoforms or cell type-specific *** TrkB–postsynaptic density protein-95 coupling provides an alternative approach to specifically boost TrkB signaling at localized synaptic sites versus global stimulation that risks many adverse side effects.

关键词： Angelman syndrome autism brain-derived neurotrophic factor depression neurodegenerative disorder neurodevelopmental disorder postsynaptic density protein-95 synaptic plasticity TrkB

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单斜辉石中氢的扩散:高温脱水实验研究

中国科学（D辑） 2000年第2期30卷 142-147页

作者：夏群科陈道公 s.carpenter 支霞臣王汝成程昊中国科技大学地球和空间科学系合肥230026 DepartmentofGeosciences The PennsylvaniastateUniversity 南京大学内生金属矿床成矿机制研究国家重点实验室南京210093

通过高温连续脱水实验，在９５０和８５０℃下，测定了女山的一个单斜辉石巨晶平行于［００１］~＊方向的氢扩散系数，分别为（６．５±土１．５）×１０^（－１２）和（１．８±０．７）×１０^（１２）ｍ~２／ｓ．碱性玄武岩中的幔源... 详细信息

通过高温连续脱水实验，在９５０和８５０℃下，测定了女山的一个单斜辉石巨晶平行于［００１］~＊方向的氢扩散系数，分别为（６．５±土１．５）×１０^（－１２）和（１．８±０．７）×１０^（１２）ｍ~２／ｓ．碱性玄武岩中的幔源单斜辉石巨晶可能是研究上地幔中水的性质、演化和氢同位素特征的可靠样品。

关键词：单斜辉石氢扩散高温脱水实验一维扩散模型

A chemical perspective on high pressure crystal structures and properties

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National science Review 2020年第1期7卷 149-169页

作者： john s.Tse Department of Physics and Engineering Physics University of Saskatchewan Saskatoon

The general availability of third generation synchrotron sources has ushered in a new era of high pressure research. The crystal structure of materials under compression can now be determined by X-ray diffraction using powder samples and, more recently, from multi-nano single crystal diffraction. Concurrently, these experimental advancements are accompanied by a rapid increase in computational capacity and capability,enabling the application of sophisticated quantum calculations to explore a variety of material *** of the early surprises is the finding that simple metallic elements do not conform to the general expectation of adopting 3D close-pack structures at high pressure. Instead, many novel open structures have been identified with no known analogues at ambient pressure. The occurrence of these structural types appears to be random with no rules governing their formation. The adoption of an open structure at high pressure suggested the presence of directional bonds. Therefore, a localized atomic hybrid orbital description of the chemical bonding may be appropriate. Here, the theoretical foundation and experimental evidence supporting this approach to the elucidation of the high pressure crystal structures of group Ⅰ and Ⅱ elements and polyhydrides are reviewed. It is desirable and advantageous to extend and apply established chemical principles to the study of the chemistry and chemical bonding of materials at high pressure.

关键词： high pressure crystal structure chemical bonding superconductivity

Opportunism and the resilience of barnacles (Cirripedia: Thoracica) to environmental change

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Integrative Zoology 2012年第2期7卷 137-146页

作者： john s.BUCKERIDGE Earth and Oceanic systems RMIT UniversityMelbourneAustralia

Cirripede-like organisms have their origins in the Palaeozoic,but until the Cainozoic,were represented primarily by pedunculated forms,such as the *** barnacles(Balanomorpha)are first recorded after the Cretaceous-Tertiary extinction *** the late Palaeogene,rapid radiation of cirripedes resulted in sufficient diversification for them to occupy most marine *** they survived both the Palaeocene-Eocene Thermal Maximum and the Pleistocene glaciation is testament to their ability to rapidly adapt to *** wide habitat distribution of balanomorphs in particular is unparalleled;they are known from the upper littoral(Chthamalus)to depths of 3600 m(Tetrachaelasma)and within this attached to rock,wood and miscellaneous flotsam,plus in symbiosis or commensalism with larger marine ***’s(1854)view of the Tertiary as the age of barnacles is reflected in this diversity,distribution and *** cirripedes are,nonetheless,at risk,from rapid habitat change,competition,pollution and,especially in light of their sessile habit,from *** paper assesses the viability of a number of cirripedes and concludes that the Lepadiformes,scalpelliformes and Balanomorpha are the most resilient,and will most quickly adapt to occupy new niches when opportunities arise.

关键词： adaptation Cirripedia distribution environmental change

The barnacle and the building:a modern morality tale

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Integrative Zoology 2008年第2期3卷 68-74页

作者： john s.BUCKERIDGE Earth and Oceanic systems Research Group RMIT UniversityMelbourneVictoriaAustralia

A rare and almost complete barnacle fossil,previously described on the basis of two isolated shell fragments,wasrecently exposed in a limestone block on the outer wall of Melbourne’s Old Magistrates’Courts in Victoria,*** courts comprise one of the oldest and grandest buildings in Melbourne and because of this they have aheritage *** heritage-listed buildings are protected from alteration by law,and as removal of the fossil wouldbe deemed“alteration”,official permission had to be obtained to extract the *** paper discusses theprocesses involved with extraction of a unique specimen from a protected building and provides an overview of thepalaeontological significance of the *** is given to the likely fate of a fossil of this nature,situateda little below eye level on a busy city street,if it was left in situ;finally,the implications of designating a holotypefrom material removed from a building are assessed.

关键词： conservation fossil barnacle heritage-listed buildings.

some biological consequences of environmental change:A study using barnacles(Cirripedia:Balanomorpha)and gum trees(Angiospermae:Myrtaceae)

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Integrative Zoology 2010年第2期5卷 122-131页

作者： john s.BUCKERIDGE Earth and Oceanic systems RMIT UniversityMelbourneAustralia

Uniformitarianism permits understanding of the past on the basis of the present,and modeling the future through consideration of the fossil *** present paper addresses the impact environmental(climatic)change has had on acorn barnacles and eucalyptus *** barnacles(Balanomorpha)are first recorded after the K/T massextinction *** the Paleogene,rapid radiation resulted in their occupying most marine *** balanomorphs survived both the Paleocene–Eocene thermal maximum and the Pleistocene glaciation is testament to their ability to adapt to opportunities;they are known from the littoral(Chamaesipho)to depths of 3600 m(Tetrachaelasma)and within this from diverse substrates:rock,wood and miscellaneous flotsam,plus in symbiosis or commensalism with most larger marine ***’s(1854)view of the late Tertiary as the age of barnacles is reflected in their diversity,distribution and *** are contrasted with the Australian Myrtaceae:plants ranging from woody shrubs to tall *** most significant is Eucalyptus sensu lato,which typifies Australia’s flora,and is characterized by aromatic leaves that produce *** has evolved strategies that result in its domination of Australian open woodlands:these include production of highly flammable eucalyptol oil(with a flashpoint of 49℃)and an unprecedented ability to regenerate following forest *** trees and barnacles first appear in the Paleogene,their earliest records are Australasian,and they both demonstrate extraordinary resilience when environmental conditions are optimal.

关键词： adaption barnacles environmental change eucalypts evolution

Detrital zircon U-Pb geochronology and geochemistry of the Riachuelos and Palma sola beach sediments,Veracruz state,Gulf of Mexico:a new insight on palaeoenvironment

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Journal of Palaeogeography 2020年第4期9卷 495-521页

作者： john s.Armstrong-Altrin Unidad de Procesos Oceánicos y Costeros Instituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autónoma de MéxicoCiudad UniversitariaCiudad de México 04510México

Zircons are abundant in the beach *** this study,surface microtexture,mineralogy,bulk sediment geochemistry,trace element composition and U−Pb isotopic geochronology of detrital zircons collected from the Riachuelos and Palma sola beach areas,southwestern Gulf of Mexico were performed to infer the sediment provenance and *** zircon microtexture was categorized as mechanically-and/or chemically-induced *** weathering index values for the Riachuelos(~72−77)and Palma sola(~71−74)beach sediments indicated moderate weathering of both of the two source *** major and trace element data of bulk sediments suggested passive margin settings for the two *** trace elemental ratios and chondrite-normalized rare earth element(REE)patterns of bulk sediments revealed that the sediments were likely sourced by felsic and intermediate igneous *** the zircon Th/U ratios(mostly more than 0.2)and zircon REE patterns(with negative Eu and positive Ce anomalies)suggested a magmatic origin for both of the beach sediments from these two *** distinct zircon age peaks respectively belonging to the Paleozoic and the Cenozoic were identified both in the Riachuelos and Palma sola beach *** geochronology comparison research between the Riachuelos−Palma sola beach sediments and potential source areas in sW Gulf of Mexico revealed that the source terrane supplied the Paleozoic zircons of this study was identified as the Mesa Central Province(MCP),and the Cenozoic zircons were transported from the nearby Eastern Alkaline Province(EAP).Moreover,although the Precambrian zircons were very few in the studied sediments,their geochronology and geochemistry results still could infer that they were contributed by the source terranes of Grenvillian igneous suites in the Oaxaca and the Chiapas Massif Complexes.

关键词： Detrital zircon Beach sediment U-Pb dating Zircon grain morphology Microtexture Mineralogy Geochemistry Geochronology Gulf of Mexico

Interaction between gut microbiota and COVID-19 and its vaccines

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World Journal of Gastroenterology 2022年第40期28卷 5801-5806页

作者： john s M Leung Cardiothoracic Unit St.Paul’s HospitalHong KongChina

The whole world has been continuously afflicted by the coronavirus disease 2019(COVID-19)pandemic for the past 3 *** countries have tried many methods to control this virus infection with varying successes and *** gut microbiota is a biosystem spanning the entire length of the digestive tract and playing important roles in health and *** is much affected by *** return it also substantially impacts *** particular,the gut microbiota has established a bidirectional interaction with the COVID-19 vaccines,enhancing or reducing vaccine efficacy by virtue of its varying ***,COVID-19 vaccines also make a substantial impact on the gut microbiota,reducing its overall population and *** is hoped that by exploring and harnessing this bidirectional interaction we may break new ground and develop new methods to prevent and treat this formidable virus infection.

关键词： Gut microbiota COVID-19 vaccines Vaccine interactions Gut microbiota alterations