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Particuology 2009年第2期7卷 106-113页

作者： Roberto Moreno-Atanasio Simon J.Antony Richard A.williams Institute of Particle Science and Engineering University of LeedsLeedsLS2 9JTUnited Kingdom

Computer simulations based on Discrete Element Method have been performed in order to investigate the influence of interparticle interactions on the kinetics of self-assembly and the mechanical strength of nanoparticle aggregates. Three different systems have been considered. In the first system the interaction between particles has been simulated using the JKR （Johnson, Kendall and Roberts） contact theory, while in the second and third systems the interaction between particles has been simulated using van der Waals and electrostatic forces respectively. In order to compare the mechanical behaviour of the three systems, the magnitude of the maximum attractive force between particles has been kept the same in all cases. However, the relationship between force and separation distance differs from case to case and thus, the range of the interparticle force. The results clearly indicate that as the range of the interparticle force increases, the self-assembly process is faster and the work required to produce the mechanical failure of the assemblies increases by more than one order of magnitude.

关键词： Nanoparticles Discrete Element Method (DEM) Self-assembly JKR model van der Waals force

Transient gene expression in western white pine using agroinfiltration

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Journal of Forestry Research 2020年第5期31卷 1823-1832页

作者： Zhenguo Ma Jun-Jun Liu Arezoo Zamany Holly williams Canadian Forest Service Natural Resources Canada506 West Burnside RoadVictoriaBC V8Z 1M5Canada

A method for transient gene expression was developed for western white pine(WWP,Pinus monticola *** ***)using reporter gene uidA encodingβ-glucuronidase(GUS).GUS was transiently expressed in cross sections of primary and secondary needles,cotyledons,and current and second year stems of WWP via vacuum-infiltration with Agrobacterium *** assays of cross sections of secondary needles showed stronger blue color indicating GUS expression at day 1 and 2 than on other days post agroinfiltration(dpa).GUS activity expressed inside WWP cells was confirmed using light *** fluorometric assays,GUS expression was high at 1 dpa and lasted until 4 dpa in detached secondary needles,while similarly high expression levels only lasted until 2 dpa in attached secondary needles then dropped *** the length of GUS-staining zones varied among different WWP organs and between growth and dormant seasons,all tested WWP tissues using the protocol had high levels of transient GUS ***,heterologous candidate genes or endogenous silencing can be expressed in various WWP tissues or organs using this agroinfiltration *** current protocol for efficient transient gene expression will aid functional genomics study of WWP and its pathogens and related conifer species.

关键词： Agrobacterium Agroinfiltration β-glucuronidase Transient gene expression Western white pine

Settling,consolidation and shear strength behaviour of coal tailings slurry

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International Journal of Mining Science and Technology 2020年第6期30卷 849-857页

作者： Shriful Islam David J.williams Marcelo Llano-Serna Chenming Zhang School of Civil Engineering The University of QueenslandQueensland 4072Australia Department of Civil and Environmental Engineering Shahjalal University of Science and TechnologySylhet 3114Bangladesh Geotechnical Engineer Klohn Crippen Berger Ltd.Queensland 4101Australia

The volume change and shear strength behaviour of tailings slurry with the changes in gravimetric moisture content is important to effectively utilise the storage volume and analysis of dam failure *** testing of tailings from a slurry-like to soil-like state is a critical task,and conventional consolidation apparatus does not have the capability of doing such testing,as the tailings slurries contain high water *** tests conducted on slurries having a 25%solids concentration showed very low efficiency;final sediment was still *** intrinsic point was identified based on pore water pressure dissipation during consolidation tests in a slurry consolidometer that can define two states of the tailings ***-like and *** the slurry-like state,the volume change was greater for Slurry 2 than Slurry 1,while the inverse was observed in the soil-like *** evolution of peak vane shear strength with the changes in moisture content was almost similar for both samples and obeyed the power *** models have been developed and validated to predict the shear strength of materials at any gravimetric moisture content or void ratio.

关键词： Settling Consolidation Vane shear strength Coal tailings slurry Slurry consolidometer

ORIGIN OF CARBONATE MATERIALS IN THE NORTHERN BASIN OF LAKE BAIKAL AND ITS RELATIONSHIP TO HOLOCENE PALEOCLIMATE

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Chinese Journal of Oceanology and Limnology 1993年第1期11卷 57-69页

作者：邱林青 F.williams Dept of Geological Sciences University of South Carolina Columbia SC 29208 U.S.A

Fine-grained disseminated carbonate was found in Holocene sediments in a core taken from the northern basin of Lake Baikal. The core had two distinct facies. a terrigenous blue-clay overlain by a diatomaceous silt. Oxygen and carbon stable isotope analyses, combined with SEM , X-ray diffraction and .palynology, show that the carbonate in the blue-clay layer is pedogenic in origin, rather than biogenic or authigenic . The S C values in the blue clay suggest that the carbonate is derived from a single source , while the carbonate in the diatom-rich layer might be transported by winds from different sources. On the assumption that the carbonate was formed during the post-glacial age and was transported primarily by river runoff, the 18O isotopic values suggest that the annual temperature in the northern Baikal drainage area was about 3℃ warmer during the middle Holocene (8500-7000 a, B. P.) than during the early Holocene (11 000-8 500a, B.P.) when the blue clay was being deposited . This interpretation

关键词： Lake Baikal carbonate oxygen isotopes carbon isotopes paleoclimate

Numerical Simulation of Interaction Between Laminar Flow and Elastic Sheet

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Transactions of Tianjin University 2012年第2期18卷 85-89页

作者：许栋 Munjiza A williams J J R School of Engineering and Material Science Queen Mary University of London Tianjin Key Laboratory of Harbour and Ocean Engineering Tianjin University

A numerical simulation of the interaction between laminar flow with low Reynolds number and a highly flexible elastic sheet is presented. The mathematical model for the simulation includes a three-dimensional finitevolume based fluid solver for incompressible viscous flow and a combined finite-discrete element method for the three-dimensional deformation of solid. An immersed boundary method is used to couple the simulation of fluid and solid. It is implemented through a set of immersed boundary points scattered on the solid surface. These points provide a deformable solid wall boundary for the fluid by adding body force to Navier-Stokes equations. The force from the fluid is also obtained for each point and then applied on the boundary nodes of the solid. The vortex-induced vibration of the highly flexible elastic sheet is simulated with the established mathematical model. The simulated results for both swing pattern and oscillation frequency of the elastic sheet in low Reynolds number flow agree well with experimental data.

关键词： fluid-structure interaction (FSI) numerical simulation immersed boundary method combined finite-discrete element method three-dimensional flow

First Pig-to-Live Human Xenotransplant Produces Mixed Results

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Engineering 2022年第9期16卷 6-8页

作者： Sarah C.P.williams Senior Technology Writer

On 7 January 2022,a 57-year-old man with terminal heart disease became the first living human to receive a genetically modified pig organ—a heart—transplanted into his chest during a 8 h surgery at the University of Maryland Medical Center in Baltimore,MD,USA(Fig.1)[1].The pig heart,provided by the biotechnology company Revivicor(Blacksburg,VA,USA),had ten gene modifications intended to boost the chances of a successful pig-to-human transplant.

关键词： Maryland Human boost

Intraoperative radiation therapy deserves to be made more readily available to patients

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Chinese Journal of Cancer Research 2016年第4期28卷 461-462页

作者： Mohammed Keshtgar Norman R.williams The Breast Unit Royal Free HospitalRoyal Free London Foundation Trust

Whole breast external beam radiotherapy is an effective adjuvant treatment for early breast cancer, and was a key factor in the move from mastectomy to breast-conserving surgery for women with low-risk disease. The logical development from partial surgical removal of the breast is partial breast radiotherapy. Several methods of delivery have been investigated, but as yet none has been widely accepted.

关键词： more Intraoperative radiation therapy deserves to be made more readily available to patients IMRT

New advances in molecular mechanisms and emerging therapeutic targets in alcoholic liver diseases

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World Journal of Gastroenterology 2014年第36期20卷 12908-12933页

作者： Jessica A williams Sharon Manley Wen-Xing Ding Department of Pharmacology Toxicology and Therapeutics The University of Kansas Medical Center Kansas City KS 66160 United States

Alcoholic liver disease is a major health problem in the United States and worldwide. Chronic alcohol consumption can cause steatosis, inflammation, fibrosis, cirrhosis and even liver cancer. Significant progress has been made to understand key events and molecular players for the onset and progression of alcoholic liver disease from both experimental and clinical alcohol studies. No successful treatments are currently available for treating alcoholic liver disease; therefore, development of novel pathophysiological-targeted therapies is urgently needed. This review summarizes the recent progress on animal models used to study alcoholic liver disease and the detrimental factors that contribute to alcoholic liver disease pathogenesis including miRNAs, S-adenosylmethionine, Zinc deficiency, cytosolic lipin-1β, IRF3-mediated apoptosis, RIP3-mediated necrosis and hepcidin. In addition, we summarize emerging adaptive protective effects induced by alcohol to attenuate alcohol-induced liver pathogenesis including FoxO3, IL-22, autophagy and nuclear lipin-1α.

关键词： Alcoholic liver disease Autophagy Fatty liver Lipin-1 FoxO3 RIP3 IL-22

Outcompeted by an invader?Interference and exploitative competition between tropical house gecko(Hemidactylus mabouia)and Barbados leaf-toed gecko(Phyllodactylus pulcher)for diurnal refuges in anthropogenic coastal habitats

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Integrative Zoology 2016年第3期11卷 229-238页

作者： Robert williams Angelo P.PERNETTA Julia A.HORROCKS Ecology and Conservation Research Group School of Pharmacy and Biomolecular SciencesUniversity of BrightonBrightonUK Ecology and Conservation Research Group University of BrightonHastingsUK Department of Biological and Chemical Sciences University of the West IndiesBarbadosWest Indies

House geckos in the genus Hemidactylus are highly successful colonizers of regions beyond their native range,with colonization often resulting in displacement of native gecko species through competitive interactions for daytime refuge(crevices)and prey *** report on data collected from nighttime surveys undertaken in April-May 2014 on Barbados,West Indies,that focused on the distribution and abundance of the endemic Barbados leaf-toed gecko(Phyllodactylus pulcher)and the introduced tropical house gecko(Hemidactylus mabouia)along unlit coastal walls and among boulders in the grounds of a hotel *** contrast to patterns of displacement of native species by *** seen elsewhere,*** was more abundant than *** on coastal walls,whereas the latter was found in greater numbers using boulders at this *** and boulders differed with regard to availability of diurnal refugia suitable for geckos,with the walls having high frequency of small crevices with openings<20 mm,and boulders offering very little cover other than the underside of the boulder *** investigate whether this niche separation was a result of differences in diurnal refuge use between the species,we conducted experimental trials in which geckos were allowed to select between refugia with different *** species selected for narrower and warmer refugia,and refugia that had been previously occupied by the other *** shared preferences for refugia type suggest that other factors underlie the niche separation observed in the *** supporting high densities of ***,coastal walls could offer important secondary habitat by augmenting the natural cliff side habitat of this endemic gecko,a finding that could be exploited for the conservation of this candidate species for Critically Endangered classification.

关键词： Barbados leaf-toed gecko Hemidactylus island endemic Phyllodactylus tropical house gecko

Particle image velocimetry evaluation of flow-altering countermeasures for local scour around a submerged circular cylinder

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International Journal of Sediment Research 2022年第4期37卷 411-423页

作者： Priscilla williams Ram Balachandar Vesselina Roussinova Ronald Barron Department of Civil and Environmental Engineering University of Windsor Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor Department of Mathematics and Statistics University of Windsor

The effect of scour countermeasures on the mechanism of local scour around a cylinder requires clarification in order to develop design methodology for use in practice. Previous investigations on countermeasure performance, though useful, have not provided adequate measurements to support this understanding. In the present investigation, particle image velocimetry(PIV) measurements were acquired at several streamwise-vertical planes in the flow field surrounding a submerged circular cylinder with a vertical splitter plate and with a rectangular collar(a horizontal base plate). Analysis of the distribution of mean streamwise velocity and Reynolds shear stress as well as the scour formation indicated that the splitter plate disrupted shear layer interaction in the wake region, reducing the width of scour downstream of the cylinder by 3%. The collar eliminated scour upstream of the cylinder entirely by providing protection at the sides of the cylinder where the shear stress exceeds the critical bed shear stress, and the streamwise velocity distribution in the region between the cylinder and the channel sidewall indicated that installation of a rectangular collar causes flow separation at a point further upstream on the cylinder surface.

关键词： Scour and erosion Local scour Pier scour Scour countermeasures Hydraulic modelling Particle image velocimetry (PIV)