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Effect of cooling rate and composition on microstructure and mechanical properties of ultrahigh-strength steels

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Journal of Iron and Steel Research International 2019年第12期26卷 1350-1365页

作者： Mohammed Ali david porter Jukka Komi Mamdouh Eissa Hoda El Faramawy Taha Mattar Materials and Mechanical Engineering Centre for Advanced Steels ResearchUniversity of OuluOulu 90014Finland Steel Technology Department Central Metallurgical Research and Development InstituteHelwanCairo 11421Egypt

The influence of cooling rate on the microstructure and mechanical properties of two new ultrahigh-strength steels(UHSSs)with different levels of C,Cr and Ni has been evaluated for the as-cooled and untempered *** UHSS had higher contents of C and Cr,while the other one had a higher Ni *** the basis of dilatation curves,microstructures,macrohardness and microhardness,continuous cooling transformation diagrams were constructed as a guide to heat treatment *** rates(CRs)of 60,1 and 0.01°C/s were selected for more detailed *** characterization was made by laser scanning confocal microscopy,field emission scanning electron microscopy combined with electron backscatter diffraction,electron probe microanalysis and X-ray *** properties were characterized using macrohardness,tensile and Charpy V-notch impact *** with the higher C and Cr contents showed lower transformation temperatures and slower bainite formation kinetics than that with the higher Ni *** cooling rates led to lower volume fractions and carbon contents of retained austenite together with finer prior austenite grain size,as well as effective final grain size and lath *** changes were accompanied by higher yield and tensile *** best combinations of strength and toughness were obtained with martensitic microstructures and by avoiding the formation of granular bainite accompanied by proeutectoid carbides at low *** the cooling rates studied,UHSS with the higher C and Cr contents showed the higher hardness and strength but at the cost of toughness.

关键词： Ultrahigh-strength steel Electroslag remelting Continuous cooling transformation diagram Microstructure feature Mechanical property

Weldable high-strength steels: Challenges and engineering applications

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机械制造文摘（焊接分册） 2015年第4期 26-28页

作者： david A.porter 谷森 Centre for Advanced Steels Research Materials Engineering University of Oulu 哈尔滨焊接研究所

68 IIW Annual Assembly&International; Conference of the International Institute of Welding,2-3 July 2015,Helsinki,Finland Portevin LectureHigh-strength steels are finding ever-wider applications as awareness of the potential benefits spread and the knowledge required by designers *** to the different processing routes,the YS levels of high-strength steels are commercially available as follows:

关键词： steels awareness Finland Welding commercially bene

Prevalence of hyponatremia in acute medical admissions in tropical Asia Pacific Australia

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Asian Pacific Journal of Tropical Medicine 2014年第1期7卷 40-43页

作者： Usman H.Malabu david porter Venkat N.Vangaveti Monsur Kazi R.Lee Kennedy Department of Medicine Townsville Hospital/James Cook UniversityQueenslandAustralia Department of Pathology Townsville Hospital/James Cook UniversityQueenslandAustralia Department of Medicine Deakin UniversityVictoriaAustralia

Objective:To determine prevalence of hyponatremia in acute medical admissions in Northern ***:We studied 469 consecutive acute medical admissions to a hospital in Australia's Far North Queensland during the colder months of June and July *** of hyponatremia and its relationship with gender,age,diagnosis and prognosis in acute medical admissions were ***:On admission,hyponatremia(plasma sodium<136 mmol/L)was present in 39.4%of patients,with mild(130—135 mmol/L),moderate(126-129 mmol/L)and severe?126 mmol/L)hyponatremia being present in 25.2%,10.7*and 3.6****,adding together admission hyponatremia with that developing during admission,45.2%of patients were affected with 11.5%moderate hyponatremia cases and 4.1%severe *** and hyperkalemia were present in 17.0%and 18.1*,***,275/469 patients(58.6*)presented with an electrolyte *** were significant correlations of hyponatremia with age but not with gender and in-hospital *** of hyponatremia was high across all diagnostic ***:The prevalence of hyponatremia appears to be high in the tropical North Australian population,being the highest prevalence reported amongst acute hospital *** previously reported correlations with age and mortality do appear to hold good for this population with a high prevalence of electrolyte *** prospective analysis on a larger population in the area is needed to confirm our findings.

关键词： Hyponatremia Prevalence Acute admissions Tropical Asia Pacific Australia

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Introduction

Journal of Foreign Languages and Cultures 2023年第2期7卷 1-3页

作者： david porter Omid Azadibougar Hunan Normal University

When one prepares to write about World Literature,one usually begins by looking up references to the word"Weltliteratur"in the works of Johann Wolfgang von Goethe,then meandering along through two centuries of literary criticism until one safely approaches the novel literary theories of the globalized 21st *** persistence of the un-Anglicized word Weltliteratur in discussions of Goethe,Marx,et al.,is a fossil of a time when expertise in the subject meant fluency in English,French,and German(perhaps along with Latin,ancient Greek,and a few other Romance and Slavic languages);a time when ein wenig untranslated German was permissible,even when *** when we outlive past assumptions,our disciplines preserve their *** should we make of the remains of World Literature?What should we do with our fossilized critical assumptions?

关键词： discussions looking literary

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压力测量的未来

流程工业 2014年第4期 52-53页

作者： david K porter AMETEK公司

压力测量行业中，坚持不懈地创新已成常态。新技术提升了品质，降低了成本，而且往往两者兼具，从而不断替代旧有技术。今天，参考记录仪正在颠覆油气、化工、发电和废水处理等行业的标准。

关键词：压力测量废水处理新技术记录仪行业

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参考压力记录仪征服了现场

流程工业 2014年第17期 46-47页

作者： david K.porter

未来的压力检测会是怎样的？图形记录仪、压力天平和模拟式压力表各有优势。现在，一种新的压力检测仪器也出现在这一领域中——参考记录仪，同时具备上述三种检测仪的能力，可以一个顶三个。

关键词：压力记录仪检测仪器压力检测压力表模拟式天平

Electroslag Refining of CrNiMoWMnV Ultrahigh-Strength Steel

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Journal of Minerals and Materials Characterization and Engineering 2017年第6期5卷 385-407页

作者： Mohammed Ali Mamdouh Eissa Hoda El Faramawy david porter Jukka Kö mi M. F. El-Shahat Taha Mattar Materials Engineering and Production Technology University of Oulu Oulu Finland Steel Technology Department Central Metallurgical Research and Development Institute Cairo Egypt Chemistry Department Ain Shams University Cairo Egypt

Increasing demands for ultrahigh-strength steels in commercial as well as military applications have raised interest in finding alternatives to the high-cost high-alloyed steel and super-alloys currently used, e.g. the use of economic low-alloy compositions processed via low-cost air induction melting and electroslag refining (ESR). In this work the yield of alloying elements and the removal of the impurities nitrogen, sulphur and phosphorus as a result of electroslag refining (ESR) in a newly developed CrNiMoWMnV ultrahigh-strength steel (UHSS) have been studied in relation to their activities in the molten metal pool. Six experimental heats of CrNiMoWMnV UHSS with different chemical compositions were designed, melted in an induction furnace (IF) and refined using ESR. This was followed by hot forging of the ingots at 1100°C to 950°C. ESR using a CaF2-CaO-Al2O3 slag system led to a high yield in Cr, Ni, Mo, W, Mn and V, while the yield of Si is low. The desulphurization of all six UHSS grades was pronounced with most of the sulphur removed either to the slag or by gas reactions. The degree of dephosphorization was only 5% irrespective of the steel composition. On the other hand, denitrification (removal of nitrogen) was achieved. It ranged from 8% to 63% depending on the steel composition. The yield of the alloying elements and removal of impurities from the steel during ESR depends on the chemical and physical properties of the ESR slag and the activity of the elements in the molten state, taking into account elemental interactions.

关键词： Ultrahigh-Strength Steel Electroslag Refining Alloying Elements Impurities Activity

Estimating the subsolar magnetopause position from soft X-ray images using a low-pass image filter

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Earth and Planetary Physics 2024年第1期8卷 173-183页

作者： Hyangpyo Kim Hyunju K.Connor Jaewoong Jung Brian M.Walsh david Sibeck Kip D.Kuntz Frederick S.porter Catriana K.Paw U Rousseau A.Nutter Ramiz Qudsi Rumi Nakamura Michael Collier Space Research Institute Austrian Academy of Sciences8042 GrazAustria Geophysical Institute University of Alaska FairbanksFairbanksAlaska 99775USA National Aeronautics and Space Administration(NASA)Goddard Space Flight Center GreenbeltMaryland 20771USA Astronomy Department University of Maryland College ParkCollege ParkMaryland 20742USA Center for Space Physics Boston UniversityBostonMassachusetts 02215USA Department of Physics and Astronomy Johns Hopkins UniversityBaltimoreMaryland 21218USA Howard University WashingtonDC 20059USA

The Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)missions will image the Earth’s dayside magneto pause and cusps in soft X-rays after their respective launches in the near future,to specify glo bal magnetic reconnection modes for varying solar wind *** suppo rt the success of these scientific missions,it is critical to develop techniques that extract the magnetopause locations from the observed soft X-ray *** this research,we introduce a new geometric equation that calculates the subsolar magnetopause position(RS)from a satellite position,the look direction of the instrument,and the angle at which the X-ray emission is *** assumptions are used in this method:(1)The look direction where soft X-ray emissions are maximized lies tangent to the magnetopause,and(2)the magnetopause surface near the subsolar point is almost spherical and thus RSis nea rly equal to the radius of the magneto pause *** create synthetic soft X-ray images by using the Open Geospace General Circulation Model(OpenGGCM)global magnetohydrodynamic model,the galactic background,the instrument point spread function,and Poisson *** then apply the fast Fourier transform and Gaussian low-pass filte rs to the synthetic images to re move noise and obtain accurate look angles for the soft X-ray pea *** the filte red images,we calculate RS and its accuracy for different LEXI locations,look directions,and solar wind densities by using the OpenGGCM subsolar magnetopause location as ground *** method estimates RS with an accuracy of10 *** accuracy improves for greater solar wind densities and during southward interplanetary magnetic *** method ca ptures the magnetopause motion during southwa rd interplaneta ry magnetic field ***,the technique will enable quantitative analysis of the magnetopause motion and help reveal the daysi

关键词： soft X-ray magnetopause reconnection low-pass filter LEXI SMILE

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教育和实践文化

建筑创作 2016年第4期 124-133页

作者：大卫.波特中央美术学院

感谢主办方邀请我来到这里。我很赞同卡尔·奥托·艾勒夫森[1]和乔纳森·D·所罗门[2]的演讲,我的演讲会跟他们的观点有所相似。什么是文化？对于生物学家来说,文化代表种子生长的土壤,能够给生命提供支持;对人类学家来说,文化就是价值... 详细信息

感谢主办方邀请我来到这里。我很赞同卡尔·奥托·艾勒夫森[1]和乔纳森·D·所罗门[2]的演讲,我的演讲会跟他们的观点有所相似。什么是文化？对于生物学家来说,文化代表种子生长的土壤,能够给生命提供支持;对人类学家来说,文化就是价值观,是人类拥有、共享并把自身和环境联系起来的价值观;对于音乐家来说,文化就是乐器的技术,是关于如何创造音乐并与听众联系起来。对这些人来说,文化就是成长、关系和价值观,包含了人类与环境的关系,以及人类如何体会这些的价值观和关系。换言之,文化不是可以孤立看待的一件＂事物＂或一系列的＂事实＂。文化适用于大到国家,小到墙上的窗口这样的事。

关键词：建筑学院种子生长文化建筑 architectural Glasgow 勒夫乔纳森 something 麦金罗门