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Microstructure and strength of a tantalum-tungsten alloy after cold rolling from small to large strains

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Journal of Materials Science & Technology 2021年第24期83卷 34-48页

作者： Guoqiang Ma Darcy A.Hughes Andrew W.Godfrey Qiang Chen niels hansena Guilin Wu College of Materials Science and Engineering Chongqing UniversityChongqing400044China Department of Mechanical Engineering Technical University of DenmarkDK-2800KgsLyngbyDenmark Fremont CAUSA Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Southwest Technology and Engineering Research Institute Chongqing400039China Technical University of Denmark Risoe CampusDK-4000RoskildeDenmark Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing100083China

Microstructural evolution of a refractory tantalum-tungsten alloy(Ta-4%W)after cold rolling from small to large von-Mises strains(0.12-2.7)was quantitatively studied using transmission electron *** subdivision was observed to take place at two *** necessary boundaries nearly paralleling to slip planes enclosed volumes further divided by diffuse cells and by remnants of Taylor *** increasing strain,the diffuse cells evolved into clear incidental dislocation boundaries enclosing cells,while the Taylor lattices *** subdivision was thus intermediate between those observed in cell forming and in non-cell forming ***,the average misorientation angle across all boundaries increased while the average boundary spacing *** of the microstructural parameters at each strain level were found to exhibit universal scaling *** microstructural evolution was found closely linking to the observed high strength and strain hardening of this *** on measured microstructural parameters,the flow stress was calculated utilizing linearly addition of the strengthening by solutes,incidental dislocation boundaries(Taylor strengthening)and geometrically necessary boundaries(Hall-Petch equation).The relative contribution of each strength mechanism evolved with increasing strain and with microstructural evolution:solutes and friction stress dominated at small strains while boundaries dominated at larger *** strengths were in close agreement with experimental tension tests and demonstrated an unexpectedly high and continuous parabolic hardening without transition across this large strain range.

关键词： Tantalum Deformation microstructure Geometrically necessary boundaries Taylor lattices Flow stress

Thermomechanical Processing of Metals: Structural Optimization

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Thermomechanical Processing of Metals: Structural Optimizati...

Reduced energy consumption by using streamlined gating systems

The Fourth International Conference on Physical and Numerical Simulation of Materials Processing (ICPNS’2004)

作者： niels hansen Centerfor FundamentalResearch:Metal Structures in Four Dimensions Ris(?) National Laboratory 4000 Roskilde Denmark

This paper concentrates on metals as aluminium, nickel, copper and iron deformed by thermomechanical processes introducing strains up to about 10 (e.g. rolling) and processes, which introduce strains from 10 to more than one hundred (e.g. high pressure torsion and sliding) The structural parameters over many length scales have been analyzed, applying physical and mathematical procedures including scaling. This analysis has created the basis for establishing relationships between processing parameters and microstructure and between microstructure and mechanical properties. Based on such relationships physical limits for the evolution of structures and properties are discussed;Such limits (or bounds) are of both scientific interest and industrial relevance as they can guide the development and application of advanced metallic materials.

关键词： Thermomechanical Structural optimization

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China Foundry 2008年第4期5卷 272-279页

作者： Sфren Skov-hansen niels Skat Tiedje DISA Industries A/S Technical University of Denmark

In foundries a lot of effort is done to minimize energy consumption in the production to reduce costs and hence increase the competitiveness. At the same time the foundries must live up to the increased demands for high quality castings. Traditional gating systems are known for a straight tapered down runner, a well base and 90° bends in the runner system. Previous work has shown that the traditional way of designing gating systems creates high inconsistency in flow patterns during filling. In the streamlined gating systems there are no sharp changes in direction and a large effort is done to confine and control the flow of the molten metal during mould filling. The main objective in the work presented here is to use the principles of the streamlined gating systems to reduce the weight of the gating system relative to the traditional layouts. By reducing the weight of gating system and thereby improving yield, the amount of molten iron needed is also reduced, hence reducing the energy consumption for melting. Experiments in real production lines have proven that it is possible to achieve a reduction in the poured weight by using the streamlined gating systems. In a layout for casting of three valve housings in a vertically parted mould the weight of the gating system was reduced by 1.1 kg changing from the traditional layouts to the streamlined gating systems. This weight reduction corresponds in this case to a 20% weight reduction for the gating system. Using streamlined gating systems with fan gates to give a beneficial heat distribution in the castings may be an efficient tool to eliminate the need for heat treatment. In the experiments the change in gating system from the traditional layout to the streamlined layout removed the need for heat treatment. This obviously means a huge energy saving in the foundry. The energy consumption for heat treatment of iron has been found to be 0.489 kWh/ kg. The valve housing in the experiments weighs 3 kg so when the need

关键词： streamlined gating systems energy consumption mould filling weight layout

Phenology of high-arctic butterflies and their floral resources： Species-specific responses to climate change

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Current Zoology 2014年第2期60卷 243-251页

作者： Toke T.HФYE Anne ESKILDSEN Rikke R. hansen Joseph J.BOWDEN niels M.SCHMIDT W.Daniel KISSLING Aarhus Institute of Advanced Studies Hoegh-Guldbergs Gade 6B bldgs. 1630-1632 DK-8000 Aarhus C Denmark Department ofBioscience Kalo Aarhus University Grenaivej 14 DK-8410 Ronde Denmark Arctic Research Centre Aarhus University C.F. Mollers Allé 8 bldg. 1110 DK-8000 Aarhus C Denmark Department of Bioscience Aarhus Aarhus University Ny Munkegade bldg. 1540 DK-8000 Aarhus C Denmark Department of Bioscience Aarhus University Frederiksborgvej 399 DK-4000 Roskilde Denmark Institute for Biodiversity and Ecosystem Dynamics (IBED) University of Amsterdam P.O. Box 94248 1090 GE AmsterdamThe Netherlands

Current global warming is particularly pronounced in the Arctic and arthropods are expected to respond rapidly to these changes. Long-term studies of individual arthropod species from the Arctic are, however, virtually absent. We examined butterfly specimens collected from yellow pitfall traps over 14 years （1996-2009） at Zackenberg in high-arctic, north-east Greenland. Specimens were previously sorted to the family level. We identified them to the species level and examined long-term species-specific phenological responses to recent summer wanning. Two species were rare in the samples （Polaris fritillary Boloria polaris and Arctic blue Plebejus glandon） and statistical analyses of phenological responses were therefore restricted to the two most abundant species （Arctic fritillary, B. chariclea and Northern clouded yellow Colias hecla）. Our analyses demonstrated a trend towards earlier flight seasons in B. chariclea, but not in C. hecla. The timing of onset, peak and end of the flight season in B. chariclea were closely related to snowmelt, July temperature and their interaction, whereas onset, peak and end of the flight season in C. hecla were only related to timing of snowmelt. The duration of the butterfly flight season was significantly positively related to the temporal overlap with floral resources in both butterfly species. We further demonstrate that yellow pitfall traps are a useful alternative to transect walks for butterfly recording in tundra habitats. More phenological studies of Arctic arthropods should be carded out at the species level and ideally be analysed in context with interacting species to assess how ongoing climate change will affect Arctic biodiversity in the near future [Current Zoology 60 （2）： 243-251, 2014].

关键词： Arctic Arthropod Flight period Greenland Pitfall trap Zackenberg

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采用流线型浇注系统减少能源消耗

铸造 2009年第7期58卷 684-689页

作者： Soren Skov-hansen niels Skat Tiedje 申泽骥(翻译) 迪砂工业有限公司丹麦海菜乌丹麦技术大学丹麦不详

本项工作的主要目的是利用流线型浇注系统的原理减小浇注系统的质量,提高出品率,从而减少对铁液的需求量,降低熔炼能量消耗。实际铸造生产线上的试验证明,应用流线型浇注系统能减少浇注系统的质量。把垂直分型,每箱3个阀体铸件的浇注系... 详细信息

本项工作的主要目的是利用流线型浇注系统的原理减小浇注系统的质量,提高出品率,从而减少对铁液的需求量,降低熔炼能量消耗。实际铸造生产线上的试验证明,应用流线型浇注系统能减少浇注系统的质量。把垂直分型,每箱3个阀体铸件的浇注系统由传统布置改为流线型布置,浇注系统的质量减少了1.1 kg,即减少了20%。在本项试验中,浇注系统由传统的转变为流线型后同时消除了铸件对热处理的需求,这在铸造车间是巨大的能量节约。此外,流线型浇注系统的球铁阀体铸件浇注试验证明,浇注温度从1 400℃降低到1 300℃,铸件未出现冷隔的危险。这可能是因为流线型浇注系统充型速度快以及扇形内浇道有减速作用。本项目还通过玻璃板前铸型试验对上述问题进行了研究。

关键词：流线型浇注系统能量消耗充型布置

Metabolic and hepatic effects of liraglutide,obeticholic acid and elafibranor in diet-induced obese mouse models of biopsy-confirmed nonalcoholic steatohepatitis

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World Journal of Gastroenterology 2018年第2期24卷 179-194页

作者： Kirstine S Tolbol Maria NB Kristiansen Henrik H hansen Sanne S Veidal Kristoffer TG Rigbolt Matthew P Gillum Jacob Jelsing niels Vrang Michael Feigh Gubra Aps Horsholm DK-2970Denmark Department of Biomedical Sciences Faculty of Health SciencesUniversity of CopenhagenCopenhagen DK-2200Denmark Section for Metabolic Imaging and Liver Metabolism The Novo Nordisk Foundation Center for Basic Metabolic ResearchFaculty of Health SciencesUniversity of CopenhagenCopenhagen DK-2200Denmark Department of Chemistry Faculty of ScienceUniversity of CopenhagenCopenhagen DK-2200Denmark

AIM To evaluate the pharmacodynamics of compounds in clinical development for nonalcoholic steatohepatitis(NASH) in obese mouse models of *** Male wild-type C57 BL/6 J mice(DIO-NASH) and Lep^(ob/ob)(ob/ob-NASH) mice were fed a diet high in trans-fat(40%), fructose(20%) and cholesterol(2%) for 30 and 21 wk, respectively. Prior to treatment, all mice underwent liver biopsy for confirmation and stratification of liver steatosis and fibrosis, using the nonalcoholic fatty liver disease activity score(NAS) and fibrosis staging system. The mice were kept on the diet and received vehicle, liraglutide(0.2 mg/kg, SC, BID), obeticholic acid(OCA, 30 mg/kg PO, QD), or elafibranor(30 mg/kg PO, QD) for eight weeks. Within-subject comparisons were performed on changes in steatosis, inflammation, ballooning degeneration, and fibrosis scores. In addition, compound effects were evaluated by quantitative liver histology, including percent fractional area of liver fat, galectin-3, and collagen 1 *** Liraglutide and elafibranor, but not OCA, reduced body weight in both models. Liraglutide improved steatosis scores in DIO-NASH mice only. Elafibranor and OCA reduced histopathological scores of hepatic steatosis and inflammation in both models, but only elafibranor reduced fibrosis severity. Liraglutide and OCA reduced total liver fat, collagen 1 a1, and galectin-3 content, driven by significant reductions in liver weight. The individual drug effects on NASH histological endpoints were supported by global gene expression(RNA sequencing) and liver lipid *** DIO-NASH and ob/ob-NASH mouse models show distinct treatment effects of liraglutide, OCA, and elafibranor, being in general agreement with corresponding findings in clinical trials for NASH. The present data therefore further supports the clinical translatability and utility of DIO-NASH and ob/ob-NASH mouse models of NASH for probing the therapeutic efficacy of compounds in preclinical d

关键词： Nonalcoholic steatohepatitis Disease models Pathology Fibrosis Liver biopsy Transcriptomics Pharmacodynamics Glucagon-like peptide-1 receptor Peroxisome proliferator-activated receptor Farnesoid X receptor

A rare diagnosis:testicular dysgenesis with carcinoma in situ detected in a patient with ultrasonic microlithiasis

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Asian Journal of Andrology 2005年第4期7卷 445-447,页

作者： Christina E.Hoei-hansen Peter Sommer Ewa Rajpert-De Meyts niels E.Skakkebaek Department of Growth and Reproduction Department of Urology University Hospital of Rigshospitalet2100 Copenhagen Denmark

A rare case is presented where a dysgenetic testis with microinvasive carcinoma in situ （CIS, also known as intratubular germ cell neoplasm of unclassified type [IGCNU] and testicular intraepithelial neoplasia [TIN]） with microinvasion to rete testis and the interstitial tissue was found in a 32-year-old man presenting with mild scrotal pain and ultrasonic testicular microlithiasis. Knowledge of the association of ultrasound and CIS is important to diagnose patients at the stage prior to development of an overt germ cell tumor. The patient had three of four disorders considered symptoms of the testicular dysgenesis syndrome （TDS）： a dysgenetic left testicle with CIS, a mild left-sided cryptorchidism （high positioned scrotal hypotrophic testis） and a slightly reduced semen quality. Therefore, it should be kept in mind that a patient with one TDS symptom may harbour the other, even CIS or testicular cancer. Accordingly, patients with one TDS symptom ought to be examined for the presence of the others, and if more that one is present, extra concern is warranted.

关键词： testicular cancer carcinoma in situ testis microlithiasis testicular dysgenesis syndrome

INT-767 improves histopathological features in a dietinduced ob/ob mouse model of biopsy-confirmed nonalcoholic steatohepatitis

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World Journal of Gastroenterology 2018年第2期24卷 195-210页

作者： Jonathan D Roth Michael Feigh Sanne S Veidal Louise KD Fensholdt Kristoffer T Rigbolt Henrik H hansen Li C Chen Mathieu Petitjean Weslyn Friley niels Vrang Jacob Jelsing Mark Young Intercept Pharmaceuticals Intercept PharmaceuticalsSan DiegoCA 92121United States Gubra Hoersholm DK-2970Denmark PharmaNest Genesis Imaging ServicesPrincetonNJ 08540United States Qualyst Transporter Solutions DurhamNC 27713United States

AIM To characterize the efficacy of the dual FXR/TGR5 receptor agonist INT-767 upon histological endpoints in a rodent model of diet-induced and biopsy-confirmed non-alcoholic steatohepatitis(NASH).METHODS The effects of INT-767 on histological features of NASH were assessed in two studies using Lep^(ob/ob)(ob/ob) NASH mice fed the AMLN diet(high fat with transfat, cholesterol and fructose). In a proof-of-conceptstudy, Lep^(ob/ob)(ob/ob) NASH mice were first dosed with INT-767(3 or 10 mg/kg for 8 wk). A second ob/ob NASH study compared INT-767(3 and 10 mg/kg) to obeticholic acid(OCA)(10 or 30 mg/kg; 16 wk). Primary histological endpoints included qualitative and quantitative assessments of NASH. Other metabolic and plasma endpoints were also assessed. A comparative assessment of INT-767 and OCA effects on drug distribution and hepatic gene expression was performed in C57 Bl/6 mice on standard chow. C57 Bl/6 mice were orally dosed with INT-767 or OCA(1-30 mg/kg) for 2 wk, and expression levels of candidate genes were assessed by RNA sequencing and tissue drug levels were measured by liquid chromatography tandem-mass *** INT-767 dose-dependently(3 and 10 mg/kg, PO, QD, 8 wk) improved qualitative morphometric scores on steatohepatitis severity, inflammatory infiltrates and fibrosis stage. Quantitative morphometric analyses revealed that INT-767 reduced parenchymal collagen area, collagen fiber density, inflammation(assessed by Galectin-3 immunohistochemistry) and hepatocyte lipid droplet area following INT-767 treatment. In a comparative study(16 wk), the FXR agonists OCA(10 and 30 mg/kg) and INT-767(3 and 10 mg/kg) both improved NASH histopathology, with INT-767 exerting greater therapeutic potency and efficacy than OCA. Mechanistic studies suggest that both drugs accumulate similarly within the liver and ileum, however, the effects of INT-767 may be driven by enhanced hepatic, but not ileal, FXR function. CONCLUSION These findings confirm the potenti

关键词： Non-alcoholic steatohepatitis INT-767 Obeticholic acid Liver biopsy FXR TGR5 Mouse model

FLECH:A Danish market solution for DSO congestion management through DER flexibility services

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Journal of Modern Power Systems and Clean Energy 2014年第2期2卷 126-133页

作者： Chunyu ZHANG Yi DING niels Christian NORDENTOFT Pierre PINSON JacobØSTERGAARD Center for Electric Power and Energy Technical University of Denmark2800 Kgs.LyngbyDenmark Danish Energy Association 1970 FrederiksbergDenmark

Future electric power systems will face new operational challenges due to the high penetration of distributed energy resources(DERs).In Denmark,distribution system operator(DSO)expects a significant congestion increased in distribution *** order to manage these congestions and mobilize the DERs as economically efficient as possible in the future distribution grid,the brand new notion of flexibility clearing house(FLECH)is proposed in this *** the aggregator-based offers,the proposed FLECH market has the ability to promote small scale DERs(upto 5 MW)for actively participating in trading flexibility services,which are stipulated accommodating the various requirements of ***,the trading setups and processes of the FLECH market are also illustrated in detail.A quantitative example is utilized to illustrate the formulation and classification of flexibility services provided by the DERs in the proposed FLECH market.

关键词： Electricity market Distributed energy resources(DERs) Aggregator Flexibility clearing house(FLECH) Flexibility services