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Large scale manufacture of magnetic polymer particles using membranes and microfluidic devices

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China Particuology 2007年第1期5卷 26-42页

作者： richard A. Williams Institute of Particle Science and Engineering School of Process Environmental and Materials Engineering University of Leeds Clarendon Road Leeds LS2 9JT United Kingdom

Magnetic polymer particles have found applications in diverse areas such as biomedical treatments, diagnosis and separation technology. These applications require the particles to have controlled sizes and narrow size distributions to gain better control and reproducibility in use. This paper reviews recent developments in the preparation of magnetic polymer particles at nano- and micro-scales by encapsulating magnetic components with dissolved or in situ formed polymers. Particle manufacture using emulsification and embedment methods produces magnetic polymer particles at micro-scale dimensions. However, the production of particles in this range using conventional emulsification methods affords very limited control over particle sizes and polydispersity. We report on alternative routes using membrane and microfluidics emulsification techniques, which have a capability to produce monodisperse emulsions and polymer microspheres （with coefficients of variation of less than 10%） in the range from submicrometer to a few 100 μm. The performance of these manufacturing methods is assessed with a view to future applications.

关键词： Magnetic polymer particles Membrane emulsification Microfluidics emulsification Large scale manufacture

Optimal chunk caching in network coding-based qualitative communication

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Digital Communications and Networks 2022年第1期8卷 44-50页

作者： Lijun Dong richard Li Futurewei Technologies Inc. 2330 Central ExpresswaySanta Clara95050USA

Network processing in the current Internet is at the entirety of the data packet,which is problematic when encountering network *** newly proposed Internet service named Qualitative Communication changes the network processing paradigm to an even finer granularity,namely chunk level,which obsoletes many existing networking policies and schemes,especially the caching algorithms and cache replacement policies that have been extensively explored in Web Caching,Content Delivery Networks(CDN)or Information-Centric Networks(ICN).This paper outlines all the new factors that are brought by random linear network coding-based Qualitative Communication and proves the importance and necessity of considering them.A novel metric is proposed by taking these new factors into *** optimization problem is formulated to maximize the metric value of all retained chunks in the local storage of network nodes under the constraint of storage limit.A cache replacement scheme that obtains the optimal result in a recursive manner is proposed *** the help of the introduced intelligent cache replacement algorithm,the performance evaluations show remarkably reduced end-to-end latency compared to the existing schemes in various network scenarios.

关键词： Internet Qualitative communication New IP Chunk caching Random linear network coding End-to-end latency Cache replacement policy Degree of freedom Distance Packet size

Optimal orientations of discrete global grids and the Poles of Inaccessibility

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International Journal of Digital Earth 2020年第7期13卷 803-816页

作者： richard Barnes Energy&Resources Group BerkeleyUSA Electrical Engineering&Comptuer Science BerkeleyUSA

Spatial analyses involving binning often require that every bin have the same area,but this is impossible using a rectangular grid laid over the Earth or over any projection of the *** global grids use hexagons,triangles,and diamonds to overcome this issue,overlaying the Earth with equally-sized *** discrete global grids are formed by tiling the faces of a ***,the orientations of these polyhedra have been chosen to satisfy only simple criteria such as equatorial symmetry or minimizing the number of vertices intersecting ***,projection distortion and singularities in discrete global grids mean that such simple orientations may not be sufficient for all use ***,I present an algorithm for finding suitable orientations;this involves solving a nonconvex optimization *** a side-effect of this study I show that Fuller’s Dymaxion map corresponds closely to one of the optimal orientations I find.I also give new high-accuracy calculations of the Poles of Inaccessibility,which show that Point Nemo,the Oceanic Pole of Inaccessibility,is 15 km farther from land than previously recognized.

关键词： Discrete grid geographic information system(GIS) geoinformatics supercomputer projections spatial statistics

Soundscapes and the sense of hearing of fishes

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Integrative Zoology 2009年第1期4卷 26-32页

作者： richard FAY Parmly Hearing Institute Loyola University ChicagoChicagoUSA

Underwater soundscapes have probably played an important role in the adaptation of ears and auditory systems of fishes throughout evolutionary time,and for all *** sounds probably contain important information about the environment and about most objects and events that confront the receiving fish so that appropriate be-havior is *** example,the sounds from reefs appear to be used by at least some fishes for their orientation and *** sorts of environmental sounds should be considered much like“acoustic daylight,”that continuously bathes all environments and contain information that all organisms can potentially use to form a sort of image of the *** present,however,we are generally ignorant of the nature of ambient sound fields impinging on fishes,and the adaptive value of processing these fields to resolve the multiple sources of *** field has focused almost exclusively on the adaptive value of processing species-specific communication sounds,and has not considered the informational value of ambient“noise.”Since all fishes can detect and process acoustic particle motion,including the directional characteristics of this motion,underwater sound fields are potentially more complex and information-rich than terrestrial acoustic *** capacities of one fish species(goldfish)to receive and make use of such sound source information have been demonstrated(sound source seg-regation and auditory scene analysis),and it is suggested that all vertebrate species have this capacity.A call is made to better understand underwater soundscapes,and the associated behaviors they determine in fishes.

关键词： acoustic daylight auditory scene analysis soundscape sound source segregation.

Combining scanning tunneling microscope (STM) imaging and local manipulation to probe the high dose oxidation structure of the Si(111)-7×7 surface

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Nano Research 2020年第1期13卷 145-150页

作者： Dogan Kaya richard J.Cobley richard E.Palmer Department of Electronics and Automation Vocational School of AdanaCukurova University01160CukurovaAdanaTurkey Nanoscale Physics Research Laboratory School of Physics and AstronomyUniversity of BirminghamEdgbastonBirminghamB152TTUK College of Engineering Swansea UniversityBay CampusFabian WaySwanseaSA18ENUK

Understanding the atomistic formation of oxide layers on semiconductors is important for thin film fabrication,scaling down conventional devices and for the integration of emerging research ***,the initial oxidation of Si(111)is studied using the scanning tunneling *** to the complete saturation of the silicon surface with oxygen,we are able to probe the atomic nature of the oxide layer *** establish the threshold for local manipulation of inserted oxygen sites to be+3.8 *** by combining imaging with local atomic manipulation are we able to determine whether inserted oxygen exists beneath surface-bonded oxygen sites and differentiate between sites that have one and more than one oxygen atom inserted beneath the *** to the creation of the thin oxide film we observe a flip in the manipulation rates of inserted oxygen sites consistent with more oxygen inserting beneath the silicon surface.

关键词： scanning tunneling microscopy(STM) local manipulation Si(111) oxidation

Landmarks in the application of electrical tomography in particle science and technology

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Particuology 2010年第6期8卷 493-497页

作者： richard A.Williams Institute of Particle Science and Engineering School of ProcessEnvironmental and Materials EngineeringUniversity of LeedsLeedsWest YorkshireLS2 9JTUK

Selected milestones in the development and use of electrical tomography in powder conveying, slurry processing and multi-phase flow are highlighted. The ability to map concentration in opaque mixtures under process-realistic conditions was a major innovation for the method and has had far reaching implications. Subsequent developments have enabled velocity information to be abstracted resulting in the ability to measure component flux and motion.

关键词： Computational fluid dynamics Fault condition and maloperation Flow measurement Flow regime identification Particle concentration Process control Process safety

Radiocarbon calibration:The next generation

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Science China Earth Sciences 2021年第3期64卷 507-510页

作者： richard A STAFF Ruiliang LIU Scottish Universities Environmental Research Centre(SUERC) University of GlasgowEast KilbrideG750QFUK School of Archaeology University of OxfordOxfordOX13TGUK

The discovery of the radiocarbon(14C)dating technique in the mid-twentieth century by Willard Libby and colleagues(Libby et al.,1949)revolutionised such fields as archaeology and palaeoclimatology that require robust chronological information to inform their *** sample yielding sufficient quantities of carbon could be dated in this manner,with the older age limit of the method(currently circa 50 to 60 thousand years ago)having been pushed back significantly since its inception.

关键词： dating dated carbon

Characterization of mudrocks:a practical application of advanced laboratory testing

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第1期12卷 1-14页

作者： richard J.JARDINE Department of Civil and Environmental Engineering Imperial College London

An integrated approach to geomaterial characterization is advocated that combines geology, in-situ testing, fabric studies, routine index experiments and advanced laboratory testing. It is shown that advanced laboratory testing can explore features such as kinematic yielding and anisotropy in stiffness or shear strength that would otherwise be impossible to quantify. A detailed study performed in London clay at the new Heathrow Terminal 5 site is used to illustrate the arguments made. It is shown that the London clay has strong anisotropy in stiffness, is highly non-linear over the strain range of engineering interest, has markedly anisotropic shear strength characteristics and exhibits a pronounced degree of brittleness. These features can impact significantly on the practical design and analysis of civil engineering works including shallow and deep foundations, tunnels and excavations, and the stability of slopes.

关键词： Mudrock Fabric Anisotropy Hollow cylinder tests

Lab experiments on the innovative rapid thick strip casting process

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International Journal of Minerals,Metallurgy and Materials 2012年第5期19卷 391-398页

作者： richard Nagy Dieter Senk Department of Ferrous Metallurgy IEHK RWTH Aachen UniversityAachen 52056Germany

Rapid thick strip casting （RTSC） by Anton Hulek, Inventmetall, is an innovative concept for the production of hot strips with a final as-cast thickness of about 25 mm before rolling. The innovation of the mechanism consists in a vertical mould performing a caterpillar motion. This moving mould has an unconventional parallelogram-shaped cross-section. The conventional rectangular shape is formed in the shaping machine, which is placed straight below the mould. Further elements of the technology are state-of-the-art. For the investigation of this new casting system theoretical calculations were complemented with practical experiments. The investigation focused mainly on two key aspects： the characteristics of the mould and the shaping process. For the practical analysis a static mould with three pairs of elements in laboratory scale was developed and commissioned by the Dept. of Ferrous Metallurgy @ RWTH Aachen University. The shaping experiments were carried out in model scale with two different materials and in variable boundary conditions. The results of these experiments delivered important mechanical as well as thermal informations about the casting system.

关键词： continuous casting rapid solidification strip metal moulds near-net-shape casting