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材料热处理学报 2004年第5期25卷 546-551页

作者： stephen J. Mashl Body cote HIP Inc. Andover Massachusetts USA

Bodycote researchers have successfully demonstrated that a T6 heat treatment can be integrated with Densal?, a proprietary, aluminum specific, hot isostatic pressing (HIP) process. In this combined operation, at least a portion of the solution heat treatment is conducted at elevated pressure. During development, two issues, adiabatic cooling during depressurization and a possible variation in the kinetics of homogenization resulting from conducting the solution heat treat at elevated pressure were perceived as factors which could alter the heat treat response from that seen in conventional processing. This paper reviews the results of experiments performed to Al-Si-Mg (A356.0) castings subjected to both combined and conventional processing routes. Results indicate that the combined HIP and heat treat process is an efficient means of achieving a microstructure characteristic of a conventionally T6 processed material while eliminating porosity within the casting. Further, the fatigue life of an A356.0 casting processed using the combined cycle can be improved by more than an order of magnitude over the as-cast and T6 treated component.

关键词： Al-Si-Mg合金热处理热等静压缩 HIP 机械性质疲劳寿命

RADIATION BOUNDARY CONDITIONS FOR MAXWELL'S EQUATIONS:A REVIEW OF ACCURATE TIME-DOMAIN FORMULATIONS

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Journal of Computational Mathematics 2007年第3期25卷 305-336页

作者： Thomas Hagstrom stephen Lau Department of Mathematics and Statistics University of New MexicoAlbuquerqueNM 87131USA Division of Applied Mathematics Brown University182 George StreetProvidenceRI 02912USA

We review time-domain formulations of radiation boundary conditions for Maxwell＇s equations, focusing on methods which can deliver arbitrary accuracy at acceptable compu-tational cost. Examples include fast evaluations of nonlocal conditions on symmetric and general boundaries, methods based on identifying and evaluating equivalent sources, and local approximations such as the perfectly matched layer and sequences of local boundary conditions. Complexity estimates are derived to assess work and storage requirements as a function of wavelength and simulation time.

关键词： Maxwell's equations Radiation boundary conditions Fast algorithms Kirchoffformulas Perfectly matched layers.

Mineral sulphide-lime reactions and effect of CaO/C mole ratio during carbothermic reduction of complex mineral sulphides

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International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 1-11页

作者： Yotamu stephen Rainford Hara Institute for Materials Research(IMR) School of ProcessEnvironmental and Materials Engineering(SPEME)University of Leeds

Mineral sulphide （MS）-lime （CaO） ion exchange reactions （MS ＋ CaO = MO ＋ CaS） and the effect of CaO/C mole ratio during carbothermic reduction （MS ＋ CaO ＋ C = M ＋ CaS ＋ CO（g）） were investigated for complex froth flotation mineral sulphide concentrates. Phases in the partially and fully reacted samples were characterised by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The primary phases during mineral sulphide-lime ion exchange reactions are Fe304, CaSO4 Cu2S, and CaS. A complex liquid phase of Ca2CuFeO3S forms during mineral sulphide-lime exchange reactions above 1173 K. The formation mechanisms of Ca2CuFeO3S liquid phase are determined by characterising the partially reacted samples. The reduction rate and extent of mineral sulphides in the presence of CaO and C increase with the increase in CaO/C ratio. The metallic phases are surrounded by the CaS rich phase at CaO/C 〉 1, but the metallic phases and CaS are found as separate phases at CaO/C 〈 1. Experimental results show that the stoichiometric ratio of carbon should be slightly higher than that of CaO. The reactions between CaO and gangue minerals （SiO2 and A1203） are only observed at CaO/C 〉 1 and the reacted samples are excessively sintered.

关键词： sulphide minerals ion exchange carbothermic reduction lime

Bacteriophage secondary infection

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Virologica Sinica 2015年第1期30卷 3-10页

作者： stephen T Abedon Department of Microbiology the Ohio State University OH 44906 USA

Phages are credited with having been first described in what we now, officially, are commemorating as the 100 th anniversary of their discovery. Those one-hundred years of phage history have not been lacking in excitement, controversy, and occasional convolution. One such complication is the concept of secondary infection, which can take on multiple forms with myriad consequences. The terms secondary infection and secondary adsorption, for example, can be used almost synonymously to describe virion interaction with already phage-infected bacteria, and which can result in what are described as superinfection exclusion or superinfection immunity. The phrase secondary infection also may be used equivalently to superinfection or coinfection, with each of these terms borrowed from medical microbiology, and can result in genetic exchange between phages, phage-on-phage parasitism, and various partial reductions in phage productivity that have been termed mutual exclusion, partial exclusion, or the depressor effect. Alternatively, and drawing from epidemiology, secondary infection has been used to describe phage population growth as that can occur during active phage therapy as well as upon phage contamination of industrial ferments. Here primary infections represent initial bacterial population exposure to phages while consequent phage replication can lead to additional, that is, secondary infections of what otherwise are not yet phage-infected bacteria. Here I explore the varying meanings and resultant ambiguity that has been associated with the term secondary infection. I suggest in particular that secondary infection, as distinctly different phenomena, can in multiple ways influence the success of phage-mediated biocontrol of bacteria, also known as, phage therapy.

关键词： lysis from without lysis inhibition coinfection parallel secondary infection phage therapy pharmacology serial secondary infection superinfection

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“暴风雪”出没注意!俄罗斯与核武器(上)

海陆空天惯性世界 2024年第2期 2-7页

作者：斯蒂芬·布兰克长弓(编译) 不详

译自美国陆军作战学院《俄罗斯核武器:过去、现在和未来》系列研究报告(斯蒂芬·布兰克/stephen ***主编)第七章。许多美国政府以及非政府分析人士都坚持认为,核武器在军事和政治层次的重要性正在不断降低。此类武器充其量只能用于对其... 详细信息

译自美国陆军作战学院《俄罗斯核武器:过去、现在和未来》系列研究报告(斯蒂芬·布兰克/stephen ***主编)第七章。许多美国政府以及非政府分析人士都坚持认为,核武器在军事和政治层次的重要性正在不断降低。此类武器充其量只能用于对其他核武器形成威慢作用,而常规武器正在迅速实现与核武器相近的作战能力,这使得有关方面对核武器的军事-政治用途日趋怀疑。

关键词：布兰克核武器俄罗斯美国政府政治层次暴风雪常规武器非政府

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“暴风雪”出没注意! 俄罗斯与核武器下

海陆空天惯性世界 2024年第3期 2-17页

作者：斯蒂芬·布兰克长弓(编译) 不详

译自美国陆军作战学院《俄罗斯核武器:过去、现在和未来》系列研究报告(斯蒂芬·布兰克/stephen ***主编)第七章。

关键词：布兰克核武器俄罗斯暴风雪

A new hadron spectroscopy

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Frontiers of physics 2015年第2期10卷 1-34页

作者： stephen Lars Olsen Center for Underground Physics Institute of Basic Science Daejeon 305-811 Korea

QCD-motivated models for hadrons predict an assortment of ＂exotic＂ hadrons that have structures that are more complex than the quark-antiquark mesons and three-quark baryons of the original quark-parton model. These include pentaquark baryons： the six-quark H-dibaryon~ and tetraquark, hybrid and glueball mesons. Despite extensive experimental searches, no unambiguous candidates for any of these exotic configurations have been identified. On the other hand, a number of meson states, one that seems to be a proton-antiproton bound state, and others that contain either charmed- anticharmed quark pairs or bottom-antibottom quark pairs, have been recently discovered that neither fit into the quark-antiquark meson picture nor match the expected properties of the QCD- inspired exotics. Here I briefly review results from a recent search for the H-dibaryon, and discuss some properties of the newly discovered states -the proton-antiproton state and the so-called XYZ mesons- and compare them with expectations for conventional quark-antiquark mesons and the predicted QCD-exotic states.

关键词： quarks charmonium pentaquarks di-baryons baryonium tetraquarks

Labechia carbonaria Smith 1932 in the Early Carboniferous of England;affinity,palaeogeographic position and implications for the geological history of stromatoporoid-type sponges

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Journal of Palaeogeography 2021年第1期10卷 1-18页

作者： stephen Kershaw Consuelo Sendino Department of Life Sciences Brunel University LondonKingston LaneUxbridge UB83PHUK Department of Earth Sciences Natural History MuseumCromwell RoadLondon SW75BDUK

Stromatoporoid sponges were very abundant during the middle Palaeozoic Era and are thought to disappear at the end of the Devonian Period in the Hangenberg Crisis. However, there are records of organisms with stromatoporoid-type structure in Carboniferous strata, the subject of this study. The Viséan fossil Labechia carbonaria Smith 1932 has been discussed previously in literature and its affinity has not been confirmed. In this study, the type material of L. carbonaria collected from the middle part of the Frizington Limestone Formation(previously called Seventh Limestone), Holkerian Substage, stored in the Natural History Museum(London, UK) and British Geological Survey(Keyworth, UK) was re-examined. The Holkerian Substage, in which L. carbonaria was found, lies between ca 335–339 Ma, and the Frizington Limestone Formation ranges from topmost Arundian to upper Holkerian, so middle Frizington Limestone Formation is likely approximately 337 Ma. L. carbonaria comprises thick long pillars connected by thin curved cyst plates consistent with the structure of the stromatoporoid genus Labechia. However, a common opinion is that L. carbonaria fossils may be mistaken for fragments of rugose corals,but there are problems with assigning it to the Rugosa. In vertical section(VS) L. carbonaria could be mistaken for a transverse section(TS) of a Carboniferous rugose coral. However, in TS L. carbonaria shows the rounded cross sections of stromatoporoid pillars. If it was a coral, septal sheets of the VS of a coral should be seen. For a rugose affinity to still apply, a coral structure would have to be composed of free trabeculae, but these are not known after the middle of the Devonian Period;there are no corals of Early Carboniferous age with the structure of ***. Another interpretation, that L. carbonaria is a chaetetid, is discounted because it lacks calicles and is very different in structure from chaetetids. We conclude that L. carbonaria is a stromatoporoid. Becau

关键词： Stromatoporoids Holkerian Viséan Carboniferous Rugosa Labechia carbonaria Labechia conferta

The Power Allocation Game on A Network:A Paradox

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IEEE/CAA Journal of Automatica Sinica 2018年第4期5卷 771-776页

作者： Yuke Li A.stephen Morse the department of political science yale university ieee the department of electrical engineering yale university

The well-known Braess paradox in congestion games states that adding an additional road to a transportation network may increase the total travel time, and consequently decrease the overall efficiency. This paper presents a paradox in a similar spirit and involves a distributed resource allocation game on networks, namely the power allocation game between countries developed in Li and Morse(2017). The paradox is that by having additional friends may actually decrease a country's total welfare in equilibrium. Conditions for this paradox to occur as well as the price of anarchy results are also derived.

关键词： Friends paradox price of anarchy resource allocation game success survival utility

Combining solar power with coal-fired power plants,or cofiring natural gas

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Clean Energy 2018年第1期2卷 1-9页

作者： stephen Mills IEA Clean Coal Centre Apsley House176 Upper Richmond RoadLondon SW152SHUK

Coal-fired power operators continue to look for ways to increase the efficiency and extend the working lives of their plants by improving operational flexibility and reducing environmental *** possible options are explored here:combining solar energy with coal-fired power generation,and cofiring natural gas in coal-fired *** techniques show *** on the individual circumstances,both can increase the flexibility of a power plant whilst reducing its *** some cases,plant costs could also be ***,any solar-based system is limited geographically to locations that receive consistently high levels of solar ***,although many coal-fired plants already burn limited amounts of gas alongside their coal feed,for cofiring at a significant level,a reliable,affordable supply of natural gas is *** is not the case *** for each technology,there are niche and mainstream locations where the criteria can be *** need for good solar radiation means that the uptake of coal-solar hybrids will be *** natural gas has wider potential:currently,the largest near-term market appears to be for application to existing coal-fired plants in the ***,where gas is available and affordable,potential markets also exist in some other countries.

关键词： coal-fired power plant coal-solar hybrid power generation solar power cofiring hybrid