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A new spallation mechanism of thermal barrier coatings on aero-engine turbine blades

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Theoretical & Applied mechanics Letters 2018年第1期8卷 7-11页

作者： Bo Yuan christopher m.harvey Rachel C.Thomson Gary W.Critchlow Simon Wang Department of Aeronautical and Automotive Engineering Loughborough University Department of materials Engineering Loughborough University School of mechanical and Equipment Engineering Hebei University of Engineering

Laboratory experiments were conducted to study the spallation behaviour of thermal barrier coatings(TBCs) on aero-engine turbine blades manufactured by the electron-beam physical vapour deposition technique(EB-PVD). Intact blades were heated at temperature 1135℃ in a furnace for certain time and then cooled to the room temperature in the laboratory condition. It was found that no spallation occurred during cooling, but spallation happened at constant room temperature after cooling. The spallation mechanism is studied by using the mechanical model developed(harvey 2017 and Wang 2017), which are based on the hypothesis of pockets of energy concentration(PECs). Some observations of the spallation behaviour are well predicted by the model.

关键词： Thermal barrier coating Interface fracture Spallation Pockets of energy concentration Buckling

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Feasibility of achieving net-zero energy performance in high-rise buildings using solar energy

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Energy and Built Environment 2024年第6期5卷 946-956页

作者： mehrdad Shirinbakhsh L.D.Danny harvey University of Toronto 100St.George StreetTorontoONM5S 3G3Canada

As part of a broad strategy to reach net-zero greenhouse gas emissions and limit global warming,many countries are requiring all new buildings to have net-zero energy *** requires that on-site energy use not exceed on-site generation of renewable energy(taken here to be solar energy),or equivalently,that the building Energy Use Intensity(EUI,kWh/m^(2)a)not exceed the supply of on-site solar energy(electricity and heat)per m^(2)of floor area per *** this basis,we find that achieving net-zero energy performance in an archetype 40-story square building in 16 different cities of North America requires EUI of 17–24 kWh/m^(2)a using PV panels,and 19–28 kWh/m^(2)a using PVT *** building orientation to a non-square floor shape can improve maximum permitted EUI by up to 50%in PV and 60%in PVT ***,the best-performing residential and commercial buildings have EUIs of 50–75 kWh/m^(2)*** if building heights are limited to 5–10 floors does the available solar energy,and thus the permitted EUI,reach 50–75 kWh/m^(2)***,we recommend that policymakers not require high-rise buildings to be net-zero energy,unless they are prepared to limit building heights to 5–10 floors.

关键词： High-rise net-zero energy buildings Building geometry Building height Solar NZEB

微纳SiCP对化学镀Ni-P-SiCP复合镀层组织和性能的影响（英文）

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稀有金属材料与工程 2024年第10期53卷 2723-2734页

作者：晁爽曹晶晶李河宗范磊杨军恒 harvey christopher martin 河北工程大学机械与装备工程学院河北省智能工业装备技术重点实验室中国矿业大学(北京)机械与电气工程学院拉夫堡大学航空与汽车工程系

通过化学镀在42Cr mo钢上沉积Ni-P-SiCP复合镀层。分析了在不同热处理温度下加工的不同SiCP浓度Ni-P-SiCP复合镀层的表面形貌和相结构。研究了Ni-P-SiCP复合镀层的显微硬度、耐腐蚀性和耐磨性。结果表明，Ni-P-SiCP复合镀层呈现花椰菜... 详细信息

通过化学镀在42Cr mo钢上沉积Ni-P-SiCP复合镀层。分析了在不同热处理温度下加工的不同SiCP浓度Ni-P-SiCP复合镀层的表面形貌和相结构。研究了Ni-P-SiCP复合镀层的显微硬度、耐腐蚀性和耐磨性。结果表明，Ni-P-SiCP复合镀层呈现花椰菜状形貌。增加SiCP浓度可以减小胞状物的尺寸。显微硬度和耐腐蚀性随着SiCP浓度的增加而先增加后降低。当SiCP浓度为5 g/L时，最大显微硬度和腐蚀电位分别为7379 mPa和-0.363 V。Ni-P-SiCP复合镀层呈现非晶态结构，漫散衍射峰的宽度随着SiCP浓度的增加而变窄。这表明SiCP抑制了P的沉积，促进了微晶转变。在350℃下热处理后，Ni-P-SiCP复合镀层结晶，导致Ni3P相沉淀。在400℃下热处理1 h可使结构最大化。镀层中Ni3P析出强化相和SiCP弥散强化相的协同作用，促进了胞状组织的致密化，从而获得了最佳的显微硬度（13 828mPa）、最佳的耐腐蚀性（-0.277 V）和优异的耐磨性。磨损机制以微切削磨料磨损为主，伴有轻微的粘着磨损和氧化磨损。

关键词： 42Crmo钢 Ni-P-SiCP复合镀层热处理耐腐蚀性磨损机理

Kaoline-based catalyst for a high stability desulfurization of sour heavy naphtha in a three-phase oscillatory baffled reactor

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Particuology 2024年第1期84卷 249-260页

作者： Hassan m.Hmood Saba A.Gheni Safaa m.R.Ahmed mudheher m.Ali Hamid Yonis Saleh mohammed H.mohammed Awad E.mohammed marwan A.mahomood Hiba R.mohammed Ahmed A.Hassan Adam.harvey North Refineries Company Ministry of OilIraq Chemical Engineering Department Tikrit UniversityIraq ministry of Oil Iraq AL-Hawija Technical Institute Northern Technical UniversityMoselIraq School of Engineering Newcastle UniversityUK

To meet the rapidly increasing demand for energy and the dramatic depletion of conventional crude oil,it is imperative to utilize sour *** no coke being produced,oxidative desulfurization(ODS)of naphtha lowers its sulfur content and average molecular *** this article,we outline a method for heavy naphtha non-extractive ODS using a very stable *** technique involves the use of a solid catalyst with oxygen gas as the *** necessitated relatively high mixing intensities;hence a three-phase Oscillatory Baffled Reactor(OBR)was *** catalyst was based on the zeolite ZSm-5,prepared from natural kaolin by a series of delamination and activation steps and impregnated with Fe.A TiO2 nanolayer was applied,using the sol-gel method,to prevent rapid *** reactor performance was evaluated to minimize the sulfur content in the naphtha *** to the protective coating,the sulfur conversion stabilized at 90%.The results of this work establish the use of natural clay-based catalysts in a continuous,three-phase ODS,particularly with regard to proving long-term *** also showed that modest ODS can be achieved using an environmentally friendly oxidant,at mild operating conditions,whilst maintaining stability.

关键词： Natural kaoline Desulfurization Three-phase Oscillatory baffled reactor

Cognitive function among military veterans with STEm occupations

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military medical Research 2024年第2期11卷 308-310页

作者： Justin T.mcDaniel Kevin N.Hascup Erin R.Hascup Ugochukwu G.Ezigbo Amanda m.Weidhuner harvey Henson David L.Albright Dale and Deborah Smith Center for Alzheimer's Research and trEatment(CARE) Southern Illinois University School of MedicineSpringfieldIL 62794USA STEm Education Research Center Southern Illinois UniversityCarbondaleIL 62901USA Department of Political Science The University of AlabamaTuscaloosaAL 35487USA

Dear Editor,There is limited research on the relationship between science,technology,engineering,and mathematics(STEm)occupational history and cognitive function in later life,especially among military veterans,who may be at greater risk for later-life cognitive *** study examines a nationally representative sample of military veterans to address this gap in knowledge.

关键词： Alzheimer's disease Veterans Science technology engineering and mathematics(STEm) Animal fluency test Dementia

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Comparison of ERA5 turbulent fluxes at the air-sea interface with measurements from a wave-following platform

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Atmospheric and Oceanic Science Letters 2024年第3期17卷 32-36页

作者： Said Benjeddou Denis Bourras christopher Luneau Aix marseille Universite National Center for Scientific ResearchMediterranean Institute of OceanographyMarseilleFrance Observatory of the Sciences of the Universe Pytheas Institute National Center for Scientific ResearchMarseilleFrance

Turbulent fluxes at the air-sea interface were estimated with data collected in 2011-2020 with a low-profile platform named OCARINA during eight experiments in five regions:2011,2015,and 2016 in the Iroise Sea;2012 in the tropical Atlantic;2014 in the Chilie-Peru upwelling;2017 and 2018 in the mediterranean Sea,and 2018 and 2020 in *** observations were carried out with moderate winds(2-10 m s^(-1))and average wave heights of 1.5 *** this study,the authors used the fluxes calculated by the bulk method using OCARINA-sampled data as the *** data can validate the fluxes estimated from ERAS reanalysis *** OCARINA and ERA5 data were taken *** do this,the authors established an algorithm to extract the OCARINA data as closely as possible to the reanalysis data in time and *** measurements of the OCARINA platform can conclude on the relevance of the widely used reanalysis data.

关键词： Ocarina ECmWF ERA5 Turbulent fluxes Louis formulation

Surgeon preferences in the treatment of thumb carpometacarpal osteoarthritis

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World Journal of Orthopedics 2024年第5期15卷 435-443页

作者： Edward J Wu Bradley W Fossum Wyatt Vander Voort christopher O Bayne Robert m Szabo Department of Orthopedic Surgery University of Minnesota Medical SchoolMinneapolisMN 55455United States Department of Orthopaedic Surgery UC Davis School of MedicineSacramentoCA 95817United States

BACKGROUND Primary thumb carpometacarpal(CmC)osteoarthritis is one of the most common conditions encountered by hand *** the vast number of operations that have been proposed,none have demonstrated results significantly superior to trapeziectomy *** The purpose of our study was to determine why surgeons opt for their technique in treating CmC *** A cross-sectional survey of active members of the American Society for Surgery of the Hand was conducted to evaluate the reasons behind their preferred technique in the treatment of isolated thumb CmC *** were contacted by email once and provided with a link to a de-identified survey consisting of 5 treatment questions and 5 demographic *** Of 950 responses were received.40.5%of surgeons preferred trapeziectomy+ligament reconstruction tendon interposition(LRTI),followed by trapeziectomy+suspensionplasty(28.2%),suture button suspension(5.9%),trapeziectomy alone(4.6%),prosthetic arthroplasty(3.2%),arthrodesis(1.1%),and other(6.6%).Proponents of trapeziectomy+LRTI cited familiarity(73.2%),exposure during fellowship(48.8%)and less proximal migration(60%)to be the main reasons affecting their *** who preferred trapeziectomy+suspensionplasty most reported simplicity(74.9%),fewer complications(45.3%),less proximal migration(43.8%),and avoidance of autogenous tissue harvest(42.7%).Advocates of suture button suspension cited avoidance of autogenous tissue harvest(80.4%),shorter immobilization(76.8%),and quicker recovery(73.2%)with their *** of trapeziectomy alone cited simplicity(97.7%),fewer complications(86.4%),and avoidance of autogenous tissue harvest(59.1%).In their comments,45%of surgeons choosing trapeziectomy alone cited evidence as an additional *** of prosthetic arthroplasty cited improved pinch strength(83.3%)and improved range of motion(63.3%),while those preferring arthrodesis cited better pinch strength(90%)and freque

关键词： Thumb carpometacarpal Osteoarthritis Trapeziectomy Ligament reconstruction tendon interposition Suspensionplasty Preferences Trends

Enantioselective Synthesis,(Chir)optical Properties,and Postsynthetic Functionalization of Furan-Containing Oxa[5]-,Oxa[6]-,and Dioxa[6]helicenes

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CCS Chemistry 2024年第10期6卷 2439-2451页

作者： Wei Fu Valentina Pelliccioli Raquel Casares-López Juan m.Cuerva martin Simon christopher Golz manuel Alcarazo Institut für Organische und Biomolekulare Chemie Georg-August-Universität Göttingen37077 Göttingen Departamento de Química Orgánica Universidad de GranadaUnidad de Excelencia Química Aplicada a Biomedicina y MedioambienteE-18071 Granada

An expedient synthesis of a series of configurationally stable oxa[5]helicenes,oxa[6]helicenes,and dioxa[6]helicenes has been developed using an intramolecular,highly enantioselective,Au-catalyzed,alkyne hydroarylation *** absolute configuration of the newly prepared structures has been established by crystallography,their inversion barriers have been determined theoretically and experimentally,and their chiroptical properties have been *** of these data with those reported for thia-or carbohelicenes sharing an otherwise identical helical framework enables the establishment of comprehensive correlations between the nature of the embedded(hetero)atom(s)and the magnitude of these *** studies on the postsynthetic functionalization of the oxahelicenes obtained are also ***,siteselective bromination at the 15-position in oxa[5]helicene 5d allows its subsequent manipulation into pyridine-containing aza-oxa[7]helicene 13d;while the two termini of oxa[6]helicene 7d have been intramolecularly cyclised into the pleiadeno[1,12,11-bcde]benzofuran derivative 15d by acidic *** transformations take place without erosion of the enantiopurity.

关键词： Au-catalysis enantioselective synthesis oxa[n]helicenes racemization dynamics postsynthetic functionalization

A nano-sheet graphene-based enhanced thermal radiation composite for passive heat dissipation from vehicle batteries

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Nano materials Science 2024年第4期6卷 443-455页

作者： Ji-Xiang Wang christopher Salmean Jiaxin Li Chaojie Lei Jun Li mingliang Zhong Bo Qi Yufeng mao Hebei Key Laboratory of man-machine Environmental Thermal Control Technology and Equipment Hebei Vocational University of Technology and Engineering College of Electrical Energy and Power EngineeringYangzhou University Department of mechanical and Aerospace Engineering The Hong Kong University of Science and Technology Taizhou Wavexploration Energy Ltd. Department of Electrical and Computer Engineering University of Toronto China Academy of Launch Vehicle Technology Beijing Sino-Spark Technology Co. Ltd. School of Environmental Science and Engineering Suzhou University of Science and Technology Institute of Optics and Electronics Chinese Academy of Sciences National Key Laboratory of Optical Field manipulation Science and Technology Chinese Academy of Sciences

In response to thermal runaway(TR) of electric vehicles, recent attention has been focused on mitigation strategies such as efficient heat dredging in battery thermal management. Thermal management with particular focus on battery cooling has been becoming increasingly significant. TR usually happened when an electric vehicle is unpowered and charged. In this state, traditional active battery cooling schemes are disabled, which can easily lead to dangerous incidents due to loss of cooling ability, and advanced passive cooling strategies are therefore gaining importance. Herein, we developed an enhanced thermal radiation material, consisting of ～1 μm thick multilayered nano-sheet graphene film coated upon the heat dissipation surface, thereby enhancing thermal radiation in the nanoscale. The surface was characterized on the nanoscale, and tested in a battery-cooling *** found that the graphene-based coating's spectral emissivity is between 91 % and 95 % in the mid-infrared region, and thermal experiments consequently illustrated that graphene-based radiative cooling yielded up to15.1 % temperature reduction when compared to the uncoated analogue. Using the novel graphene surface to augment a heat pipe, the temperature reduction can be further enlarged to 25.6 %. The new material may contribute to transportation safety, global warming mitigation and carbon neutralization.

关键词： Battery thermal management Nano-sheet graphene Functional material Passive cooling Thermal radiation