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Nanocrystalline and Nanocomposite Magnetic Materials and Their Applications

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Journal of Iron and Steel Research International 2007年第4期14卷 69-74页

作者： robert D Shull Magnetic Materials Group National Institute of Standards and TechnologyGaithersburg MD 20899MarylandUSA

Nanocrystalline materials can possess bulk properties quite different from those commonly associated with conventional large-grained materials. Nanocomposites, a subset of nanocrystalline materials, in addition have been found to possess magnetic properties which are similar to, but different from, the properties of the individual constituents. New magnetic phenomena, unusual property combinations, and both enhanced and diminished magnetic property values are just some of the changes observed in magnetic nanocomposites from conventional magnetic materials. Here, a description will be presented of some of the exciting new properties discovered in nanomaterials and the magnetic applications envisioned for them.

关键词： nanocomposite ferromagnet magnetoresistance magnetic refrigeration domain imaging

Controversies in and challenges to our understanding of hepatitis C

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World Journal of Gastroenterology 2007年第31期13卷 4168-4176页

作者： robert G Batey Area Director Drug and Alcohol Clinical Services Hunter New England Area Health Services. Newcastle New South Wales Australia

Discovered in 1989, the hepatitis C virus (HCV) continues to cause signifi cant morbidity and mortality world-wide despite a huge research commitment to defining and understanding the virus and the disease it causes. This paper discusses a number of areas where progress in the management of the HCV have not kept pace with the scientifi c understanding of the HCV. It is suggested that in the fi elds of HCV prevention and providing access to treatment, practice falls short of what could be achieved. The role of alcohol in the pathogenesis of HCV liver injury is discussed. Discrimination against those with HCV infection and particularly those in prison settings fails to match good clinical practice. The complicated processes of sharing information between specialty groups is also discussed in an attempt to optimise knowledge dissemination in this field.

关键词： Hepatitis C Alcohol Injecting drug use Prisons Genetic variation Cirrhosis Liver cell cancer

Anosov and expanding attractors

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Science China Mathematics 2020年第9期63卷 1929-1934页

作者： robert F.Williams Department of Mathematics University of Texas at AustinAustinTX 78705USA Institute for Advanced Study PrincetonNJ 08540USA

An earlier conjecture is settled with an immersion of a 2-dimensional branched *** obstructions in linear algebra and tiling theory are studied rst.

关键词： Anosov expanding attractor Cantor set ber bundle

Heat stress in pigs and broilers:role of gut dysbiosis in the impairment of the gut-liver axis and restoration of these effects by probiotics,prebiotics and synbiotics

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Journal of Animal Science and Biotechnology 2023年第2期14卷 465-480页

作者： robert Ringseis Klaus Eder Institute of Animal Nutrition and Nutrition Physiology Justus-Liebig-University GiessenHeinrich‑Buff‑Ring 26‑3235392 GiessenGermany

Heat stress is one of the most challenging stressors for animal production due to high economic losses resulting from impaired animal’s productivity,health and *** the fact that all farm animal species are susceptible to heat stress,birds and pigs are particularly sensitive to heat stress due to either lacking or non-functional sweat ***-vincing evidence in the literature exists that gut dysbiosis,a term used to describe a perturbation of commensal gut microbiota,develops in broilers and pigs under heat *** to the protective role of commensal bacteria for the gut barrier,gut dysbiosis causes a disruption of the gut barrier leading to endotoxemia,which contributes to the typical characteristics of heat stressed broilers and growing and growing-finishing pigs,such as reduced feed intake,decreased growth and reduced lean carcass weight.A substantial number of studies have shown that feeding of probiotics,prebiotics and synbiotics is an efficacious strategy to protect broilers from heat stress-induced gut barrier disruption through altering the gut microbiota and promoting all decisive structural,biochemical,and immunologi-cal elements of the intestinal *** most of the available studies in heat stressed broilers,the alterations of gut microbiota and improvements of gut barrier function induced by feeding of either probiotics,prebiotics or synbiot-ics were accompanied by an improved productivity,health and/or welfare when compared to non-supplemented broilers exposed to heat *** findings indicate that the restoration of gut homeostasis and function is a key target for dietary interventions aiming to provide at least partial protection of broilers from the detrimental impact of heat stress *** the fact that the number of studies dealing with the same feeding strategy in heat stressed pigs is limited,the available few studies suggest that feeding of probiotics might also be a suitable approach to enhance productivi

关键词： Broilers Commensal bacteria Gut dysbiosis Heat stress Pigs Prebiotics Probiotics Synbiotics

Necrotic enteritis and antibiotic-free production of broiler chickens:Challenges in testing and using alternative products

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Animal Nutrition 2024年第1期16卷 288-298页

作者： robert J.Moore School of Science RMIT UniversityBundooraVictoria 3083Australia

The global trend towards raising broiler chickens without the use of in-feed antibiotics(IFAs)means that there is an ongoing need to develop alternative treatments capable of delivering the benefits that IFAs previously *** supported the productivity performance of chickens and played a key role in maintaining their *** enteritis(NE)is an important disease of broilers that affects health,productivity,and welfare,and was previously well controlled by ***,with the reduction in IFA use,NE is resurgent in some *** and various feed additives,including pre-,pro-,and postbiotics,phytobiotics,fatty acids,and phage therapies have been introduced as alternative methods of NE *** some of these feed additives have specific activity against the NE pathogen,Clostridium perfringens,most have the more general goal of reinforcing gut *** reviews of the effects of many of these feed additives on gut health have been published ***,rather than cover previously well reviewed areas of research this review focuses on the challenges and pitfalls in undertaking experimental assessment of alternative NE treatments and translating laboratory research to real world commercial production *** review is based on the author's particular experience,reading,thoughts,and analysis of the available information and inevitably presents a particular understanding that is likely to be at odds with others thinking on these *** is put forward to stimulate thinking and discussion on the issues covered.

关键词： Necrotic enteritis Clostridium perfringens Vaccines Feed additive Farm management

The Orosirian(1800–2050 Ma)plate tectonic episode:Key for reconstructing the Proterozoic tectonic record

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Geoscience Frontiers 2023年第3期14卷 1-9页

作者： robert J.Stern Geosciences Dept. U Texas at DallasRichardsonTX 75083-0688United States

Eight lines of evidence indicate that the Orosirian Period in mid-Paleoproterozoic time was characterized by plate tectonics:ophiolites,low T/P metamorphism including eclogites,passive margin formation,tall mountains,paleomagnetic constraints,ore deposits,abundant S-type granites,and seismic images of paleo-subduction *** plate tectonic episode occurred about 1 billion years earlier than the present plate tectonic episode began in Neoproterozoic *** two plate tectonic episodes bracket the‘Boring Billion’,which may have been a protracted single lid tectonic episode that began when the supercontinent Nuna or Columbia *** of multiple lines of evidence for Orosirian plate tectonics demonstrates that Earth’s tectonic style can be reconstructed with some confidence back to at least Early Paleoproterozoic time,and thus the absence of compelling evidence for Mesoproterozoic plate tectonics is not obvious due to poor preservation.A tectono-magmatic lull2.3 Ga suggests an earlier episode of single lid *** for two episodes of plate tectonics and two episodes of single lid tectonics indicates that Earth switched between single lid and plate tectonics multiple times during the last 2.4 Ga.

关键词： Plate tectonics Single lid tectonics Urey ratio Paleoproterozoic

Hydrologic Time Scale:A Fundamental Stream Characteristic

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Journal of Earth Science 2022年第5期33卷 1291-1297页

作者： robert E.Criss Department of Earth and Planetary Sciences Washington University in St.LouisSt.LouisMO63130USA

A new,fundamental catchment attribute called the hydrologic time scaleτgoverns the rate of delivery of runoff to a particular site,and is equal to∫Qdt/∫|dQ|,where Q is discharge and t is *** value ofτfor any gauged site is readily calculated from tabulated discharge data by replacing the integrals with *** quantity,coupled with the square root of catchment area,√A,form a coordinate pair that embodies the characteristic time and length scales for any catchment,which govern its flow *** fitting constants used in several unit hydrograph models are simple multiples ofτ,so knowledge ofτallows rapid calibration of these models for the particular site,facilitating flow prediction from rainfall *** ofτreflect many different landscape attributes,but for multiple sub-basins in watersheds with homogeneous land use and lithologic conditions,they correlate linearly with √*** ratio √A/τprovides a characteristic velocity that is high for channelized,floodprone rivers,for flashy urban streams with high impervious cover,and for sites downstream of hydropower *** with low velocities are resistant to flooding,as their landscapes have a greater ability to delay the delivery of runoff by retention,detention,and infiltration into the groundwater system.

关键词： unit hydrograph time constant flash floods impervious cover urban streams flashiness hydrogeology

A radical reinterpretation of the growth and form of the stromatolite Conophyton lituus(Maslov)from evidence of syngenetic biofilm mineralisation

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Journal of Palaeogeography 2022年第1期11卷 69-84页

作者： robert V.Burne Research School of Earth Sciences The Australian National University CanberraACT 0200Australia School of Earth and Environmental Sciences The University of QueenslandBrisbaneQLD 4072Australia

Conophyton(Maslov)is a cylindroidal stromatolite form-genus characterized by nested conical ***-preserved Conophyton,up to 4 m tall and with basal diameters of up to 50 cm,are exposed in the Proterozoic Atar Formation of Mauritania,where many occur together,in growth position,as fields of individual columns spaced between 5 and 70 cm *** uniformity of these forms and their regular distribution suggest that they grew in quiet-water environments below wave *** for their penecontemporaneous organomineralization is indicated by nearby toppled examples of undeformed Conophyton forms alongside eroded lithified Conophyton fragments in carbonate *** characteristics of Conophyton have been used to classify the structures-the form of the lamination and the nature of its axial structure.A mathematical/physical model provides an explanation for the growth pattern of *** predicts that coniform structures with thickened axial zones form when upward organic growth of a biofilm moderately exceeds the rate of its *** varying characteristics of these features between different forms of Conophyton are thought to reflect biomineralization of the decaying biofilm rather than differences in the composition of microbial communities.A modern example of a syngenetic mineralization process capable of producing similar structures has been observed in the contemporary sediments of Lake Preston,Western Australia,where benthic microbial mats are being transformed into coniform lithified *** initial biomineralization of the coniform mat forms magnesium silicate that first coats and permineralizes web-like microbial extracellular polymeric substances(EPS)and then coalesces into a uniform mass that provides mechanical strength to the *** a later stage,massive carbonate crystal growth occurs that over-prints much of this texture,leaving only small,remnant areas of the magnesium silicate *** fossil Conophyton are composed o

关键词： Conophyton Morphogenesis Proterozoic Stromatolite Microbialite Mineralisation Biofilm Lake Clifton Lake Preston Maslov

Investigating the raveling test for full-depth reclamation

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Frontiers of Structural and Civil Engineering 2018年第2期12卷 222-226页

作者： robert HILL Andrew BRAHAM Department of Civil Engineering University of Arkansas Fayetteville AR 72701 USA

Full-Depth Reclamation （FDR） is a sustainable method of building pavement structure compared to more traditional rehabilitation methods. Traffic is generally returned to an FDR project before a surface course is applied, as water in the FDR needs time to evaporate from the structure. This should not be done too quickly or raveling occurs. Currently, there is no test to quantify the timing of return to traffic. In this study, the ＂Raveling test of cold mixed bituminous emulsion samples＂（ASTM D7196） was used to compare asphalt emulsion and asphalt foam FDR. Asphalt emulsion samples were cured at ambient and 40℃ temperatures, while asphalt foam samples were cured at ambient temperatures. Raveling test data was collected from 0 to 48 hours of curing, however, samples were often not able to withstand fifteen minutes of testing. Therefore, the ＂time lasted＂（the time the raveling head loses contact with the surface of the sample） was recorded. In general, the asphalt emulsion samples that were cured in the oven at 40℃ had a longer time lasted and showed higher potential for determination of return to traffic. In addition, the asphalt emulsion samples had a longer time lasted than the asphalt foam samples at ambient temperatures.

关键词： raveling full depth reclamation