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Study on numerical simulation of nodular graphite iron microstructure formation

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China foundry 2004年第S1期1卷 44-48页

作者： j.Yang S.f.Su X.B.Qi X.L.Ai Shenyang Research institute of foundry Shenyang 110022LiaoningP.R.China School of Material Science and Engineering Shenyang Polytechnic UniversityShenyang 110023LiaoningP.R.China

In this paper, the mathematical and physical model was developed based on thermodynamics and solidification theory before the eutectoid transformation of nodular graphite iron occurred. The Local Element Substitute and Magnification Method was brought forward and 3-dimensional numerical simulation program based on the model and the new assistant algorithm was developed and used to calculate the samples. Results of calculation have good agreement with experimental data. To display the microstructure formation during solidification of nodular graphite iron, a 2-dimensional numerical simulation program combined with the result of the 3-dimensional numerical simulation of experimental samples was compiled.

关键词： nodular graphite iron microstructure numerical simulation the Local Element Substitute and Magnification Method dynamically display

Velocity Profile Effect on Woltman Water Meters Performance

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Velocity Profile Effect on Woltman Water Meters Performance

The 12～(th) International Conference on flow Measurement

作者： Palau C.V. Arregui f. j. Palau G. Espert V. Institute for Water Technology. Politechnical University of Valencia. Camino de Vera s/n. Apartado 22012.46071 Valencia. Spain Institute for Water Technology. Politechnical University of Valencia. Camino de Vera s/n. Apartado 22012.46071 Valencia. Spain Dept. Rural and Agrifood Engineering. Politechnical University of Valencia. Camino de Vera s/n. Apartado 22012.46071 Valencia. Spain Institute for Water Technology. Politechnical University of Valencia. Camino de Vera s/n. Apartado 22012.46071 Valencia. Spain

＜正＞ This paper describes a detailed study, covering analytic as experimental aspects, about the effect on a commercial Woltman meter of different hydraulic fittings and configurations such as butterfly and gate valves. firstly, a three-dimensional numerical simulation using computational fluid dynamics techniques （CfD） is used to calculate the alteration of the velocity profile by upstream fittings. Afterwards, the theoretical analysis undertakes the study of blade forces and torques generated by the fluid flow （Baker, 2000）. finally, laboratory test validate the analytical procedure proposed.

关键词： Woltman water meter flow distortion accuracy meter Computational fluid Dynamics

Simultaneous Preservation of Soil Structural Properties and Phospholipid Profiles: A Comparison of Three Drying Techniques

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Pedosphere 2008年第3期18卷 284-287页

作者： L. j. DEACON D. V. GRINEV j. W. CRAWfORD j. HARRIS K. RITZ I. M. YOUNG National Soil Resources Institute Department of Natural Resources School of Applied Sciences Cranfield University Cranfield MK43 0AL (UK) SIMBIOS Centre University of Abertay Dundee DD1 1HG (UK) Integrated Earth Systems Science Institute Department of Natural Resources School of Applied Sciences Cranfield University Cranfield MK43 0AL (UK)

There is a need to simultaneously preserve evidence of interactions between the biological community and soil structural properties of a soil in as near an intact （natural） state as possible. Three dehydration techniques were implemented and assessed for their ability to minimise disruption of both biological and physical properties of the same arable soil sample. Dehydration techniques applied until samples were at constant weight were i） air-drying at 20℃ （AD）; ii） -80 ℃ freeze for 24 h, followed by freeze-drying （-80fD）; and iii） liquid nitrogen snap freeze, followed by freeze-drying （LNPD） and were compared to a moist control. Physical structure was determined and quantified in three dimensions using X-ray computed tomography and microbial phenotypic community composition was assessed using phospholipid fatty acid （PLPA） profiling. This study confirms that any form of dehydration, when preparing soil for simultaneous biological and physical analysis, will alter the soil physical properties, and cause some change in apparent community structure. freeze-drying （both the LNfD and -80fD treatments） was found to minimise disruption （when compared to the moist control soil） to both the soil physical properties and the community structure and is a preferable technique to air-drying which markedly alters the size and character of the pore network, as well as the phenotypic profile. The LNfD was the preferred treatment over the -80fD treatment as samples show low variability between replicates and a fast turn-around time between samples. Therefore snap freezing in liquid nitrogen, followed by freeze drying is the most appropriate form of dehydration when two sets of data, both physical and biological, need to be preserved simultaneously from a soil core.

关键词： biological community dehydration phospholipid profile physical properties preservation

Experimental Study on Deoxidization of Bariumand Barium Alloy

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journal of Materials Science & Technology 1999年第5期15卷 400-404页

作者： Shi, Yf Chen, BP fu, j El Gammal, T Univ Sci & Technol Beijing Met Sch Beijing 100083 Peoples R China Rhein Westfal TH Aachen Inst Eisenhuttenkunde Aachen Germany

Based on the review of latest papers related to the application of barium alloy, the deoxidization effects of barium and barium alloy, and the dynamic characteristics of molten bath have been systematically studied by means of the convection free bath, natural convection bath, air and vacuum induction melting experiments. It was found that both the total oxygen content and soluble oxygen content in molten bath decreased rapidly. The results obtained provided practical and theoretical basis for further synthetic applications of barium alloy in metallurgical industry.

关键词： Barium

Evolution of the design of Venturi devices for the delivery of dry particles to skin or mucosal tissue

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Evolution of the design of Venturi devices for the delivery ...

The 24th International Symposium on Shock Waves

作者： G.Costigan G.L.Brown f.V.Carter B.j.Bellhouse Department of Engineering Science University of OxfordOxford OX2 6PEUnited Kingdom

The behaviour of bursting membrane devices, used to accelerate powder particles to velocities high enough to penetrate the skin, has been extensively studied at Oxford University. Over-expansion of a supersonic jet leads to flow separation, and powder concentrates in this separated jet[1,2]. Correctly expanded shock tube devices, which produce uniform gas velocities[4], require the powder to be delivered over a narrow time window (of order 0.2 ms) to be accelerated to maximum velocity. This paper reviews the evolution of devices designed to use the Venturi effect to entrain particles into a quasi-steady gas flow.

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Signaling events during initiation of arbuscular mycorrhizal symbiosis

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journal of Integrative Plant Biology 2014年第3期56卷 250-261页

作者： Alexa M.Schmitz Maria j.Harrison Boyce Thompson Institute for Plant Research Plant Pathology and Plant-Microbe Biology Cornell University

Under nutrient-limiting conditions, plants will enter into symbiosis with arbuscular mycorrhizal （AM） fungi for the enhancement of mineral nutrient acquisition from the surrounding soil. AM fungi live in close, intracellular association with plant roots where they transfer phosphate and nitrogen to the plant in exchange for carbon. They are obligate fungi, relying on their host as their only carbon source. Much has been discovered in the last decade concerning the signaling events during initiation of the AM symbiosis, including the identification of signaling molecules generated by both partners. This signaling occurs through symbiosis-specific gene products in the host plant, which are indispensable for normal AM development. At the same time, plants have adapted complex mechanisms for avoiding infection by pathogenic fungi, including an innate immune response to general microbial molecules, such as chitin present in fungal cell walls. How it is that AM fungal colonization is maintained without eliciting a defensive response from the host is still uncertain. In this review, we present a summary of the molecular signals and their elicited responses during initiation of the AM symbiosis, including plant immune responses and their suppression.

关键词： Arbuscular mycorrhizal fungi chitin chitooligosaccharide cutin LysM MAMP-triggered immunity Myc-LCO Nod factor strigolactones symbiosis

The floristic relationship between the upland and lowland Carboniferous wetlands of Variscan Euramerica——Evidence from some medullosalean pteridosperm fronds

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journal of Palaeogeography 2019年第2期8卷 130-141页

作者： Christopher j.Cleal Borja Cascales-Mi?ana Department of Natural Sciences National Museum Wales CNRS University of Lille

Alethopteris grandinii represents remains of fronds of a medullosalean pteridosperm(probably a small tree) that rapidly migrated across the lowland wetland habitats of Variscan Euramerica in middle Asturian(late Moscovian)*** was probably caused by changing drainage patterns within the lowland coal swamps,in response to climate and landscape ***,these medullosaleans had first appeared rather earlier,in early Bolsovian(early Moscovian) times,in upland wetland *** upland habitats may have pre-adapted these plants to the changed condition in the lowland coal swamps.

关键词： Carboniferous Coal swamps Medullosales Upland Migration

Recycling of minute metal scraps by semisolid processing:Manufacturing of design materials

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Transactions of Nonferrous Metals Society of China 2010年第9期20卷 1567-1571页

作者： S.SUGIYAMA T.MER A j.YANAGIMOTO Institute of Industrial Science The University of Tokyo

As a new attempt to recycle minute metal scraps, the possibility of manufacturing design materials by semisolid extrusion processing was shown.A design material with an intended shape, such as a character or petal shape, was manufactured using minute metal ***, a design material with an intended color pattern for each metal, such as red copper in a white aluminum matrix, resembling grainlike wood, was manufactured by mixing two or more types of minute metal *** addition, secondary design materials, which have engraved patterns on the surface of the target metal made by an electric discharge machine using the above primary design material as an electrode, were manufactured.

关键词： semisolid processing minute metal scraps recycling design material

Excitation-Coupled Calcium Entry in fast and slow twitch muscles

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Excitation-Coupled Calcium Entry in fast and slow twitch mus...

第十一届全国钙信号和细胞功能研讨会

作者： B.Mosca L.Bergamelli j.Eckhard S.Treves f.Zorzato Department of Life Sciences and Biotechnology University of Ferrara Dept.of Anesthesiology University Hospital Basel

Skeletal muscle dihydropyridine receptors(Cav1.1) act as Ca channels and voltage sensors to initiate muscle contraction by activating ryanodine receptors, the Ca release channels of the sarcoplasmic reticulum. Cav1.1 channel activity is enhanced by a retrograde stimulatory signal delivered by the ryanodine receptor. jP45 is a junctional sarcoplasmic reticulum membrane protein interacting with Cav1.1 and the Ca storage protein calsequestrin(CASQ). We hypothesize that jP45 and CASQ form a signalling pathway modulating Cav1.1 channel activity. We tested this hypothesis in a variety of mouse models, including WT, jP45 KO, CASQ1 KO, CASQ2 KO, jP45/CASQ1 double KO(DKO1), jP45/CASQ2 double KO(DKO2) and jP45/CASQ1/CASQ2 triple KO(TKO). Our results show that Ca transient in flexor digitorum brevis(fDB) muscle from DKO1, DKO2 and TKO fibresevoked by tetanic stimulation in fibres, result from massive Ca influx via La3+-and nifedipine-sensitive calcium channels(1, 2). Calcium entry enahnced by ablation of both jP45/CASQ1 and jP45/CASQ2 complexes supports tetanic force development infast EDL-and slow-twitch Soleus muscles(1,2). We also found that CASQs interact with jP45 at [Ca] similar to those present in the lumen of the sarcoplasmic reticulum at rest, while [Ca] similar to those present in the SR lumen after depolarisation-induced calcium release cause the dissociation of jP45 from CASQs. We conclude that the complex jP45/CASQs is a negative regulator of excitation-coupled calcium entry, and that tetanic force development in fast and slow twitch muscles is supported by the dynamic interaction between jP45 and CASQs

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