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Synthetic and Systems Biotechnology 2017年第1期2卷 28-38页

作者： A.l.English A.Boufridi r.j.Quinn D.I.Kurtboke Genecology research Centre and Faculty of Science HealthEducation and EngineeringUniversity of the Sunshine CoastMaroochydore DCQLD4558Australia Eskitis Institute for Drug Discovery Griffith UniversityNathanQLD4111Australia

A near-shore marine intertidal environment-associated Streptomyces isolate(USC-633)from the Sunshine Coast region of Queensland,Australia,cultivated under a range of chemically defined and complex media to determine optimal parameters resulting in the secretion of diverse array of secondary metabolites with antimicrobial properties against various antibiotic resistant *** extraction,fractioning and re-testing of active metabolites resulted in persistent antibacterial activity against Escherichia coli(Migula)(ATCC 13706)and subsequent Nuclear Magnetic resonance(NMr)analysis of the active fractions confirmed the induction of metabolites different than the ones in fractions which did not display activity against the same bacterial *** findings again confirmed the value of One StraineMany Compounds(OSMAC)approach that tests a wide range of growth parameters to trigger bioactive compound secretion increasing the likelihood of finding novel therapeutic *** isolate was found to be adaptable to both marine and terrestrial conditions corresponding to its original nearshore marine intertidal *** variations in its morphology,sporulation and diffusible pigment production were observed when different growth media were used.

关键词： Marine streptomycetes Marine biodiscovery Fermentation media Antibiotics Marine natural products Pigments

Efficient Orbit Propagation of Orbital Elements Using Modified Chebyshev Picard Iteration Method

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Computer Modeling in Engineering & Sciences 2016年第1期111卷 65-81页

作者： j.l.read A.Bani Younes j.l.junkins Graduate research Assistant Texas A&M UniversityCollege StationTXUSA. Assistant Professor Khalifa UniversityAbu DhabiUAE. Distinguished Professor Texas A&M UniversityCollege StationTXUSA.

This paper focuses on propagating perturbed two-body motion using orbital elements combined with a novel integration *** previous studies show that Modified Chebyshev Picard Iteration(MCPI)is a powerful tool used to propagate position and velocity,the present results show that using orbital elements to propagate the state vector reduces the number of MCPI iterations and nodes required,which is especially useful for reducing the computation time when including computationally-intensive calculations such as Spherical Harmonic gravity,and it also converges for>5.5x as many revolutions using a single segment when compared with cartesian *** for the Classical Orbital Elements and the Modified Equinoctial Orbital Elements(the latter provides singularity-free solutions)show that state propagation using these variables is inherently well-suited to the propagation method *** benefits are achieved using a segmentation scheme,while future expansion to the two-point boundary value problem is expected to increase the domain of convergence compared with the cartesian *** is an iterative numerical method used to solve linear and nonlinear,ordinary differential equations(ODEs).It is a fusion of orthogonal Chebyshev function approximation with Picard iteration that approximates a long-arc trajectory at every *** studies have shown that it outperforms the state of the practice numerical integrators of ODEs in a serial computing environment;since MCPI is inherently massively parallelizable,this capability is expected to increase the computational efficiency of the method presented.

关键词： Propagation Integration Orbital Mechanics Classical Elements Modified Equinoctial Chebyshev Picard Iteration MCPI Polynomials Initial Value Problem IVP.

Numerical studies towards practical large-eddy simulation

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journal of Thermal Science 2007年第4期16卷 328-336页

作者： j.Boudet j.Caro l.Shao E.lév(?)que lMFA laboratoire

large-eddy simulation developments and validations are presented for an improved simulation of turbulent internal flows. Numerical methods are proposed according to two competing criteria： numerical qualities （precision and spectral characteristics）, and adaptability to complex configurations. First, methods are tested on academic test-cases, in order to abridge with fundamental studies. Consistent results are obtained using adaptable finite volume method, with higher order advection fluxes, implicit grid filtering and ＂low-cost＂ shear-improved Smagorinsky model. This analysis particularly focuses on mean flow, fluctuations, two-point correlations and spectra. Moreover, it is shown that exponential averaging is a promising tool for lES implementation in complex geometry with deterministic unsteadiness. Finally, adaptability of the method is demonstrated by application to a configuration representative of blade-tip clearance flow in a turbomachine.

关键词： lES adaptable methods validation

Increase in the Hydrophilicity and lewis Acid-Base Properties of Solid Surfaces Achieved by Electric Gliding Discharge in Humid Air: Effects on Bacterial Adherence

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Plasma Science and Technology 2009年第2期11卷 187-193页

作者： j.O.KAMGANG M.NAITAlI j.-M.HErrY M.-N.BEllON-FONTAINE j.-l.BrISSET r.BrIANDET laboratory of Interfacial Electrochemistry and Analytical Chemistry University of Rouen INrA(National Institute for Agricultural research) UMR 763 Bio-adhesion and Hygiene of Materials AgroParisTech UMR 763 Bio-adhesion and Hygiene of Materials AgroParisTech UMR763 Bio-adhesion and Hygiene of Materials

This study addressed the effects of treatment with gliding discharge plasma on the surface properties of solid materials, as well as the consequences concerning adherence of a model bacterium. As evaluated by contact angles with selected liquids, plasma treatment caused an increase in surface hydrophilicity and in the lewis acid-base components of the surface energy of all materials tested. These modifications were more marked for low density polyethylene and stainless steel than for polytetrafiuoroethylene. After treatment, the hydrophilicity of the materials remained relatively stable for at least 20 days. Moreover, analysis of the topography of the materials by atomic force microscopy revealed that the roughness of both polymers was reduced by glidarc plasma treatment. As a result of all these modifications, solid substrates were activated towards micro-organisms and the adherence of S. epidermidis, a negatively charged lewis-base and mildly hydrophilic strain selected as the model, was increased in almost all the cases tested.

关键词： gliding arc plasma surface energy properties polymers stainless steel surface hydrophilicity atomic force microscopy

A test method for evaluating the thermal environment of underground coal mine refuge alternatives

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International journal of Mining Science and Technology 2019年第3期29卷 343-355页

作者： D.S.Yantek l.Yan N.W.Damiano M.A.reyes j.r.Srednicki CDC NIOSH

Since 2009,the Mine Safety and Health Administration(MSHA)has required mines to install refuge alternatives(rAs)in underground coal *** of the biggest concerns with occupied rAs is the possible severity of the resulting thermal *** 30 CFr 7.504,the maximum allowable apparent temperature(AT)for an occupied rA is specified as 35℃(95°F).Manufacturers must conduct heat/humidity tests to demonstrate that their rAs meet the 35℃(95°F)AT *** these tests,heat input devices are used to input the metabolic heat of actual miners.A wide variety of test methods,sensors,and heat input devices could be used when conducting such *** 2012,the National Institute for Occupational Safety and Health(NIOSH)has conducted over thirty 96-hour heat/humidity tests on four different *** paper discusses the test equipment and procedures used during these *** information is useful for rA manufacturers conducting rA heat/humidity tests,for other researchers investigating rA heat/humidity buildup,and for those who need to assess the thermal environment of any confined space where people may be trapped or are seeking refuge.

关键词： refuge chamber refuge alternative Confined space Thermal environment Test method Temperature

Analysis of PFAAs in American alligators part 2： Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat

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journal of Environmental Sciences 2017年第11期29卷 31-38页

作者： jessica j.Tipton louis j.Guillette jr Susan lovelace Benjamin B.Parrott Thomas r.rainwater jessica l.reiner College of Charleston Charleston SC 29724 USA Medical University of South Carolina Department of Obstetrics and Gynecology Charleston SC 29425 USA University of Georgia Odum School of Ecology Savannah River Ecology Laboratory Jackson SC 29831 USA Torn Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science Clemson University P.O. Box 59(5 Georgetown SC 29442 USA National Institute of Standards and Technology Chemical Sciences Division Hollings Marine Laboratory Charleston SC 29412 USA

Exposure to perfluorinated alkyl acids（PFAAs） has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs,occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators（Alligator mississippiensis） in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid（PFOS） concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11 ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat.

关键词： Public hunt American alligator Dietary exposure PFOS Consumption advisory Contaminant consumption

Oxidation behavior and microstructural evolution of FeCoNiTiCu five-element high-entropy alloy nanoparticles

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journal of Materials Science & Technology 2024年第10期177卷 133-141页

作者： H.Bai r.Su r.Z.Zhao C.l.Hu l.Z.ji Y.j.liao Y.N.Zhang Y.X.li X.F.Zhang Key laboratory for Anisotropy and Texture of Materials(MOE) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China Institute of Advanced Magnetic Materials College of Materials and Environmental EngineeringHangzhou Dianzi UniversityHangzhou310012China

High-entropy alloys(HEAs)have attracted extensive attention ascribed to their unique physical and chemical properties induced by the cocktail ***,their oxidation behaviors,in particular at nanoscale,are still lack because of multi-element complexity,which could also be completely differ-ent from the bulk *** this work,we synthesized FeCoNiTiCu five-element HEA nanopar-ticles(NPs)with uniform elemental distribution by arc-discharging approach,and further investigated their oxidation behaviors at 250 ℃,and 350 ℃.The morphology,structure and element distribution of NPs were analyzed by transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS)and electron energy loss spectroscopy(EElS).The surface oxidation in FeCoNiTiCu NPs during the high-temperature process can induce nanoscale pores at core/shell interfaces by Kirkendall effect,and even the eventual coalescence into a single ***,the oxidation states of NPs with diameters(d)varying from 60 to 350 nm were analyzed in detail,revealing two typical configurations:hollow(dlk-shell structures(d>150 nm).The experimental results were complemented by first-principles calculations to investigate the diffusion behaviors of five elements,evidencing that the surface oxidation strongly alters the surface segregation preferences:(1)in the initial stage,Cu and Ni appear to prefer segregating on the surface,while Co,Ti and Fe tend to stay in the bulk;(2)in the oxidation process,Cu prefers to stay in the center,while Ti segregates to the surface ascribed to the reduced po-tential *** study gives new insights into oxidation of nanoscale HEA,and also provides a way for fabrication of high-entropy oxides with controllable architectures.

关键词： High-entropy alloy Nanoparticles Oxidation Kirkendall effect Exchange bias effect

Adult bobcat(lynx rufus)habitat selection in a longleaf pine savanna

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Ecological Processes 2018年第1期7卷 206-217页

作者： Andrew r.little l.Mike Conner Michael j.Chamberlain Nathan P.Nibbelink robert j.Warren Warnell School of Forestry and Natural resources University of Georgia180 E.Green StAthensGA 30602USA joseph W.jones Ecological research Center at Ichauway NewtonGeorgia 39870USA

Background:Pine savannas are primarily managed with frequent prescribed fire(≤3 years)to promote diversity of flora and fauna,and to maintain open,park-like conditions needed by species such as the endangered red-cockaded woodpecker(Picoides borealis).However,a knowledge gap exists in our understanding of bobcat(lynx rufus)habitat selection in longleaf pine savannas and research is warranted to direct our future management ***:We examined bobcat habitat selection in a pine savanna managed with frequent fires at two spatial scales(i.e.,study area boundary[hereafter,landscape scale])and annual area of use[95%kernel density;local scale],and assessed effects of prescribed fire on bobcat habitat ***,we monitored 45 bobcats(16 males and 29 females)during 2001–***:We found differential habitat selection by *** the landscape scale,female bobcats were closer to mixed pine-hardwoods,young pine,and secondary roads,but farther from mature pine and hardwoods stands relative to *** found no difference in selection of agriculture,shrub-scrub,and primary roads between *** the annual area of use scale,female bobcats were closer to secondary roads,but farther from agriculture and shrub-scrub relative to *** found no difference in selection of mature pine,mixed pine-hardwoods,hardwoods,young pine,and primary roads between *** primarily selected for stands burned≤1.1 years ***:Our results show that bobcats exploit a broad range of habitat types in pine landscapes managed with frequent fire and commonly use recently burned stands(≤1.1 year post-fire),suggesting prey in many areas of this system are at risk of bobcat ***,we suggest land managers consider scale of selection by bobcats when developing habitat management strategies.

关键词： Georgia Habitat selection lynx rufus Pinus palustris Prescribed fire

Isogeometric Collocation:A Mixed Displacement-Pressure Method for Nearly Incompressible Elasticity Dedicated to Professor Karl Stark Pister for his 95th birthday

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Computer Modeling in Engineering & Sciences 2021年第12期129卷 1125-1150页

作者： S.Morganti F.Fahrendorf l.De lorenzis j.A.Evans T.j.r.Hughes A.reali Department of Electrical Computer and Biomedical EngineeringUniversita degli Studi di PaviaPavia27100Italy Institute of Applied Mechanics Technische Universitat BraunschweigBraunschweig38106Germany Department of Mechanical and Process Engineering Zurich8092Switzerland Department of Aerospace Engineering Sciences University of Colorado BoulderColorado80309USA Institute for Computational Engineering and Sciences The University of Texas at AustinTexas78712USA Department of Civil Engineering and Architecture Universita degli Studi di PaviaPavia27100Italy

We investigate primal and mixed u−p isogeometric collocation methods for application to nearly-incompressible isotropic *** primal method employs Navier’s equations in terms of the displacement unknowns,and the mixed method employs both displacement and pressure *** benchmarks for what might be considered acceptable accuracy,we employ constant-pressure Abaqus finite elements that are widely used in engineering *** a basis of comparisons,we present results for compressible *** the methods were completely satisfactory for the compressible ***,results for low-degree primal methods exhibited displacement locking and in general deteriorated in the nearly-incompressible *** results for the mixed methods behaved very well for two of the problems we studied,achieving levels of accuracy very similar to those for the compressible *** third problem,which we consider a“torture test”presented a more complex story for the mixed methods in the nearly-incompressible case.

关键词： Isogeometric analysis isogeometric collocation nearly-incompressible elasticity

Analysis of PFAAs in American alligators part 1： Concentrations in alligators harvested for consumption during South Carolina public hunts

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journal of Environmental Sciences 2017年第11期29卷 24-30页

作者： jessica j.Tipton louis j.Guillette jr Susan lovelace Benjamin B.Parrott Thomas r.rainwater jessica l.reiner College of Charleston Charleston SC 29424 USA Medical University of South Carolina Department of Obstetrics and Gynecology Charleston SC 29425 USA University of Georgia Odum School of Ecology Savannah River Ecology Laboratory Jackson SC 29831 USA Tom Yawkey Wildlife Center & Belle W. Baruch Institute of Coastal Ecology and Forest Science Clemson University P.O. Box 596 Georgetown SC 29442 USA National Institute of Standards and Technology Chemical Sciences Division Hollings Marine Laboratory Charleston SC 29412 USA

Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids（PFAAs） were historically produced as protective coatings for many household items and currently persist in the environment, wildlife, and humans. PFAAs have been linked to immune suppression, endocrine disruption, and developmental toxicity in wildlife and laboratory studies. This study examines the American alligator, Alligator mississippiensis,as an important indicator of ecosystem contamination and a potential pathway for PFAA exposure in humans. Alligator meat harvested in the 2015 South Carolina（SC） public hunt season and prepared for human consumption was collected and analyzed for PFAAs to determine meat concentrations and relationships with animal body size（total length）, sex, and location of harvest. Of the 15 PFAAs analyzed, perfluorooctane sulfonate（PFOS） was found in all alligator meat samples and at the highest concentrations（median 6.73 ng/g）. No relationship was found between PFAA concentrations and total length or *** of one or all compounds varied significantly across sampling locations, with alligators harvested in the Middle Coastal hunt unit having the highest PFOS concentrations（median 16.0 ng/g; p = 0.0001）. Alligators harvested specifically from Berkley County, SC（located in the Middle Coastal hunt unit） had the highest PFOS concentrations and the greatest number of PFAAs detected（p 〈 0.0001）. The site-specific nature of PFAA concentrations in alligator meat observed in this study suggests a source of PFAA contamination in Berkley County, SC.

关键词： Perfluorinated alkyl acids American alligators South Carolina Perfluorooctane sulfonate(PFOS) Dietary exposure