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Continental velocity through Precambrian times:The link to magmatism,crustal accretion and episodes of global cooling

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Geoscience Frontiers 2013年第1期4卷 7-36页

作者： j.d.A.Piper Geomagnetism Laboratory Geology and GeophysicsSchool of Environmental SciencesUniversity of Liverpool.Liverpool L69 7ZEUK

Quasi-integrity of continental crust between Mid-Archaean and Ediacaran times is demonstrated by conformity of palaeomagnetic poles to near-static positions between -2.7-2.2 Ga, -1.5-1.2 Ga and -0.75-0.6 Ga. Intervening data accord to coherent APW loops turning at ＂hairpins＂ focused near a continental-centric location. Although peripheral adjustments occurred during Early Proterozoic （-2.2 Ga） and Grenville （- 1.1 Ga） times, the crust retained a low order symmetrical crescent-shaped form constrained to a single global hemisphere until break-up in Ediacaran times. Conformity of palaeomagnetic data to specific Eulerian parameters enables definition of a master Precambrian APW path used to estimate the root mean square velocity （VRMS） of continental crust between 2.8 and 0.6 Ga. A long interval of little polar movement between -2.7 and 2.2 Ga correlates with global magmatic shutdown between -2.45 and 2.2 Ga, whilst this interval and later slowdown at -0.75-0.6 Ga to velocities of 〈2 cm/year correlate with episodes of widespread glaciation implying that these prolonged climatic anomalies had an internal origin; the reduced input of volcanically-derived atmospheric greenhouse gases is inferred to have permitted freeze-over conditions with active ice sheets extending into equatorial latitudes as established by low magnetic inclinations in glaciogenic deposits. VRMS vari- ations through Precambrian times correspond to the distribution of U-Pb ages in orogenic granitoids and detrital zircons and demonstrate that mobility of continental crust has been closely related to crustal tectonism and incrementation. Both periods of near-stillstand were followed by rapid VRMS recording massive heat release from beneath the continental lid at -2.2 and 0.6 Ga. The first coincided with the Lomagundi-jatuli isotopic event and led to prolonged orogenesis accompanied by continental flooding and reconfiguration of the crust on the Earth＇s surface; the second led to continental break-up and i

关键词： Continental velocity Precambrian Palaeopangaea Palaeomagnetism Magmatism Tectonics

dominant Lid Tectonics behaviour of continental lithosphere in Precambrian times:Palaeomagnetism confirms prolonged quasi-integrity and absence of supercontinent cycles

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Geoscience Frontiers 2018年第1期9卷 61-89页

作者： j.d.A.Piper Geomagnetism Laboratory Department of Earth and Ocean Sciences University of Liverpool

Although Plate Tectonics cannot be effectively tested by palaeomagnetism in the Precambrian aeon due to the paucity of high precision poles spanning such a long time period,the possibility of Lid Tectonics is eminently testable because it seeks accordance of the wider dataset over prolonged intervals of time;deficiencies and complexities in the data merely contribute to *** of palaeomagnetic poles across a quasi-integral continental crust for time periods of up to thousands of millions of years,together with recognition of very long intervals characterised by minimal polar motions(～2.6-2.0,～1.5-1.25 and～0.75-0.6 Ga)has been used to demonstrate that Lid Tectonics dominated this *** new PALEOMAGIA database is used to refine a model for the Precambrian lid incorporating a large quasiintegral crescentric core running from South-Central Africa through Laurentia to Siberia with peripheral cratons subject to reorganisation at～2.1,～1.6 and～1.1 *** model explains low levels of tidal friction,reduced heat balance,unique petrologic and isotopic signatures,and the prolonged crustal stability of Earth's"Middle Age",whilst density concentrations of the palaeomagnetic poles show that the centre of the continental lid was persistently focussed near Earth's rotation axis from～2.8 to 0.6 *** exception was the～2.7-2.2 Ga interval defined by～90°polar movements which translated the periphery of the lid to the rotation pole for this quasi-static period,a time characterised by glaciation and low levels of magmatic activity;the～2.7 Ga shift correlates with key interval of mid-Archaean crustal growth to some 60-70%of the present volume and REE signatures whilst the～2.2 Ga shift correlates with the Lomagundiδ～(13)C and Great Oxygenation *** palaeomagnetic signature of breakup of the lid at～0.6 Ga is recorded by the world-wide Ediacaran development of passive margins and associated environmental signatures of new ocean *** event defined the end of a

关键词： Lid Tectonics Plate tectonics Archaean Proterozoic Palaeomagnetism PALEOMAGIA

dimensional analysis and extended hydrodynamic theory applied to long-rod penetration of ceramics

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defence Technology（防务技术） 2016年第4期12卷 334-342页

作者： j.d.CLAYTON Impact Physics RdRL-WMP-C US Army Research Laboratory Aberdeen Proving Ground A.james Clark School of Engineering University of Maryland College Park

Principles of dimensional analysis are applied in a new interpretation of penetration of ceramic targets subjected to hypervelocity impact. The analysis results in a power series representation – in terms of inverse velocity – of normalized depth of penetration that reduces to the hydrodynamic solution at high impact velocities. Specifically considered are test data from four literature sources involving penetration of confined thick ceramic targets by tungsten long rod projectiles. The ceramics are Ad-995 alumina, aluminum nitride, silicon carbide, and boron *** data can be accurately represented by the linear form of the power series, whereby the same value of a single fitting parameter applies remarkably well for all four ceramics. Comparison of the present model with others in the literature(e.g., Tate's theory) demonstrates a target resistance stress that depends on impact velocity, linearly in the limiting case. Comparison of the present analysis with recent research involving penetration of thin ceramic tiles at lower typical impact velocities confirms the importance of target properties related to fracture and shear strength at the Hugoniot Elastic Limit(HEL) only in the latter. In contrast, in the former(i.e., hypervelocity and thick target) experiments, the current analysis demonstrates dominant dependence of penetration depth only by target mass density. Such comparisons suggest transitions from microstructure-controlled to density-controlled penetration resistance with increasing impact velocity and ceramic target *** and hosting by Elsevier B.V. on behalf of China Ordnance Society.

关键词： Ceramics Terminal ballistics Armor dimensional analysis Hydrodynamics

Influence of food availability,plant productivity,and indigenous forest use on ranging behavior of the endangered samango monkey(Cercopithecus albogularis schwarzi),in the Soutpansberg Mountains,South Africa

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Integrative Zoology 2020年第5期15卷 385-400页

作者： Edwin j.parker Russell A.HIL Andrew T.L.ALLAN Caroline HOWLETT Nicola F.KOYAMA School of Natural Sciences and Psychology Liverpool John Moores UniversityLiverpoolUK Primate and Predator Project Lajuma Research CentreLouis TrichardtSouth Africa department of Anthropology Durham UniversityDurhamUK department of Zoology University of VendaThohoyandouSouth Africa School of Anthropology and Conservation University of KentKentUK

Understanding the determinants of ranging patterns in species susceptible to habitat fragmentation is fundamental for assessing their long-term adaptability to an increasingly human-dominated *** aim of this study was to determine and compare the influence of ground-based food availability,remotely sensed plant productivity,and indigenous forest use on the ranging patterns of the endangered samango monkey(Cercopithecus albogularis schwarzi).We collected monthly ranging data on two habituated samango monkey groups,from February 2012 to december 2016,from our field site in the Soutpansberg Mountains,South *** used linear mixed models to explore how food availability,plant productivity,and indigenous forest use influenced monthly ranging patterns,while controlling for group size,number of sample days and day *** found that as more areas of high plant productivity(derived from remotely sensed EVI)were incorporated into the ranging area,both total and core monthly ranging areas *** addition,both total ranging area and mean monthly daily path length decreased as more indigenous forest was incorporated into the ranging ***,we found no effect of either ground-based food availability or remotely sensed plant productivity on ranging *** findings demonstrate the behavioral flexibility in samango monkey ranging,as samangos can utilize matrix habitat during periods of low productivity but are ultimately dependent on access to indigenous forest *** addition,we highlight the potential of using remotely sensed areas of high plant productivity to predict ranging patterns in a small ranging,forest-dwelling guenon,over ground-based estimates of food availability.

关键词： food availability forest use plant productivity ranging patterns remote sensing samango monkey

deposition of Nano-Scaled Coatings Using Inductively Coupled Plasma

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journal of Rare Earths 2004年第Z2期22卷 153-156页

作者： d H jung B Park j j Lee School of Materials Science and Engineering College of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea School of Materials Science and EngineeringCollege of EngineeringSeoul National UniversitySeoul 151-744Korea

Nano-scaled Ti-B-N coatings could be produced by inductively coupled plasma (ICP) assisted magnetron spurtering. The properties and microstructure of the coating can be changed drastically by applying ICP to conventional magnetron sputtering. In this work, an internal type rf ICP process is used. The core of this technology is the efficient production and control of self-depositing ions and reactive gas ions by an induced electric field. Ti-B-N coatings were prepared by using a TiB2 target and a gas mixture of N2 and Ar at 200 ℃ and a pressure of 60 mTorr. In addition to ICP, the effect of the substrate bias voltage on the structure and properties of the coating was investigated. By applying ICP and a bias voltage to the substrate the hardness of the Ti-B-N coating is increased by more than 75 GPa, as a result of enhanced ionization in the plasma. The Ti-B-N coating, which has the highest hardness, shows the best surface uniformity and a very dense structure with a grain size of 3 nm. This sample also shows a high crystallinity compared to the coating prepared using other deposition parameters.

关键词： nano-scaled coatings industively conpled plasma

Physical separation from the mate diminishes male＇s attentiveness towards other females： a study in monogamous prairie voles Microtus ochrogaster

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Current Zoology 2017年第5期63卷 537-544页

作者： Christine j. dELEVAN Natalia A. ROdRIGUEZ Karine M. LEGZIM Fayeza ALIOU jamie T. parker Maryam BAMSHAd department of Biological Sciences Lehman College--The City University of New York Bronx NY 10468 USA

We tested whether continuous cohabitation in monogamous voles affects the mated male＇s atten-tiveness to his breeding partner versus another female. Each male was housed in a 3-chamber ap-paratus with a Focal female （FF） and a Control female （CF） for 13 days then placed in a T-maze toassess his attentiveness to and memory of those females. The distal male remained physically sep-arated from both females, but received their distal cues. The Separate male cohabited with the FFfor 3 days then remained physically separated from both females. The disrupt male＇s continuouscohabitation with the FF was disrupted by having him physically separated from her after 10 daysand placed with the CF for the last 3 days. The Continuous male cohabited continuously with the FFfor 13 days. With females in the T-maze, the Separate and disrupt males spent more time near theFF＇s box and the disrupt males spent more time manipulating the FF＇s box than the CF＇s box. TheSeparate males groomed themselves more when near the FF＇s box than the CF＇s box. The distaland Continuous males＇ attentiveness to the two females did not differ. Results suggest that phys-ical distance from the partner may reduce male＇s attentiveness toward other potential *** voles might be similar to socially monogamous primates in using tactile cues as a signal formaintaining their social bonds.

关键词： attachment, monogamy, partner preference, partner separation, social cognition.

Brain injury and neural stem cells

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Neural Regeneration Research 2018年第1期13卷 7-18页

作者： parker E.Ludwig Finosh G.Thankam Arun A.Patil Andrea j.Chamczuk devendra K.Agrawal department of Clinical and Translational Science Creighton University School of Medicine department of Neurosurgery Creighton University School of Medicine

Many therapies with potential for treatment of brain injury have been investigated. Few types of cells have spurred as much interest and excitement as stem cells over the past few decades. The multipotentiality and self-renewing characteristics of stem cells confer upon them the capability to regenerate lost tissue in ischemic or degenerative conditions as well as trauma. While stem cells have not yet proven to be clinically effective in many such conditions as was once hoped, they have demonstrated some effects that could be manipulated for clinical benefit. The various types of stem cells have similar characteristics, and largely differ in terms of origin; those that have differentiated to some extent may exhibit limited capability in differentiation potential. Stem cells can aid in decreasing lesion size and improving function following brain injury.

关键词： brain injury brain trauma infarction ischemia neural stem cells neuronal regeneration stroke

Plasma density measurement and downstream etching of silicon and silicon oxide in Ar/NF3 mixture remote plasma source

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Plasma Science and Technology 2019年第6期21卷 52-57页

作者： H j YEOM d H CHOI Y S LEE j H KIM d j SEONG S j YOU H C LEE Korea Research Institute of Standards and Science(KRISS) Daejeon 34113 Republic of Korea department of Physics Chungnam National University Daejeon 34134 Republic of Korea

In this study,plasma density measurements were performed near the plume region of the remote plasma source (RPS) in Ar/NF3 gas mixtures using a microwave cutoff *** measured plasma density is in the range of 1010-1011 cm-3 in the discharge conditions with RPS powers of 2-4 kW and gas pressures of 0.87-4 *** plasma density decreased with increasing gas pressures and RPS powers under various Ar/NF3 mixing *** decrease in the plasma density measured at the fixed measurement position (plume region) can be understood by the reduction of the electron energy relaxation length with increases in the gas pressures and mixing ratio of NF3/(Ar/NF3).We also performed downstream etching of silicon and silicon oxide films in this *** etch rate of the silicon films significantly increases while the silicon oxide is slightly etched with the gas pressures and *** was also found that the etch rate strongly depends on the wafer position on the processing chamber electrode,and that the etch selectivity reached 96-131 in the discharge conditions of RF powers (3730-4180 W) and gas pressures (3.6-4 Torr).

关键词： remote plasma source electron density cutoff probe downstream etch

Landslides at Qingjiang River in the downstream Area of Shuibuya dam Site, China

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journal of China University of Geosciences 2006年第2期17卷 158-162页

作者： Kallen d 项伟 Ehret d Rohn j University of Karlsruhe Department of Applied Geology Faculty of Engineering China University of Geosciences

To enhance the general knowledge of landslides in China, the dAAd （German Academic Exchange Service） is financing an investigative project. As part of this project, at the Qingjiang （清江） River, a 10 km^2 area downstream of the Shuibuya （水布垭） dam site was geologically and geotechnicaUy mapped to gather information concerning landslides and their correlation to lithology, slope angles and texture. The geological mapping contained the characterization of the lithological units. The characterization of the shape of landslides and the classification of rocks into units with similar geotechnical behavior is contained in the geotechnical map. Samples were taken and investigated using X-ray diffraction to identify the clay minerals and geotechnical tests to determine the effective shear angle and cohesion of rocks and soils. Geotechnical mapping showed a close connection between lithology, slope angle and texture concerning the occurrence of landslides. Most landslides occur on the northern bank of the Qingjiang River where the dip angle of the bedding is nearly parallel to the slope, resulting in potential and effective slide planes. On the southern bank only sporadic and small landslides occur because the bedding is antipodal to the slope angle. This pilot work is a base for further and more detailed investigations in this area.

关键词： landslide geotechnical mapping geological mapping shear test and X-ray diffraction Shuibuya dam site.