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nanoscale architecture of ceria-based model catalysts: Pt-Co nanostructures on well-ordered CeO_(2)(111) thin films

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Chinese Journal of Catalysis 2020年第6期41卷 985-997页

作者： Yaroslava Lykhach tomásSkála Armin neitzel nataliya Tsud Klára Beranová Kevin CPrince Vladimír Matolín Jorg Libuda Interface Research and Catalysis Erlangen Catalysis Resource CenterFriedrich-Alexander-Universit?t Erlangen-NürnbergEgerlandstrasse 391058 ErlangenGermany Charles University Faculty of Mathematics and PhysicsDepartment of Surface and Plasma ScienceV Hole?ovi?kách 218000 PragueCzech Republic Elettra-Sincrotrone Trieste SCpA Strada Statale 14km 163.534149 Basovizza-TriesteItaly

We have prepared and characterized atomically well-defined model systems for ceria-supported Pt-Co core-shell catalysts. Pt@Co and Co@Pt core-shell nanostructures were grown on well-ordered CeO2(111) films on Cu(111) by physical vapour deposition of Pt and Co metals in ultrahigh vacuum and investigated by means of synchrotron radiation photoelectron spectroscopy and resonant photoemission spectroscopy. The deposition of Co onto CeO2(111) yields CoCeO2(111) solid solution at low Co coverage(0.5 ML), followed by the growth of metallic Co nanoparticles at higher Co coverages. Both Pt@Co and Co@Pt model structures are stable against sintering in the temperature range between 300 and 500 K. After annealing at 500 K, the Pt@Co nanostructure contains nearly pure Co-shell while the Pt-shell in the Co@Pt is partially covered by metallic Co. Above 550 K, the re-ordering in the near surface regions yields a subsurface Pt-Co alloy and Pt-rich shells in both Pt@Co and Co@Pt nanostructures. In the case of Co@Pt nanoparticles, the chemical ordering in the near surface region depends on the initial thickness of the deposited Pt-shell. Annealing of the Co@Pt nanostructures in the presence of O2 triggers the decomposition of Pt-Co alloy along with the oxidation of Co, regardless of the thickness of the initial Pt-shell. Progressive oxidation of Co coupled with adsorbate-induced Co segregation leads to the formation of thick CoO layers on the surfaces of the supported Co@Pt nanostructures. This process is accompanied by the disintegration of the CeO2(111) film and encapsulation of oxidized Co@Pt nanostructures by CeO2 upon annealing in O2 above 550 K. notably, during oxidation and reduction cycles with O2 and H2 at different temperatures, the changes in the structure and chemical composition of supported Co@Pt nanostructures were driven mainly by oxidation while reduction treatments had little effect regardless of the initial thickness of the Pt-shell.

关键词： Core-shell nanoparticles Model catalyst Pt-Co Cerium oxide Chemical ordering Synchrotron radiation photoelectron spectroscopy

Pass/Fail Criterion for a Simple Radiation

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Modern Instrumentation 2012年第3期1卷 27-33页

作者： tom Burr Avigdor Gavron neutron Science Center Los Alamos National Laboratory Los Alamos USA Statistical Sciences Los Alamos National Laboratory Los Alamos USA

One of the simplest tests of a radiation portal monitor (RPM) is a series of n repeats (a vehicle drive-through) in which the ith repeat records a total number of counts Xi and alarms if Xi ≥ T where T is an alarm threshold. The RPM performance tests we consider use n repeats to estimate the probability p = P(Xi ≥ T). This paper addresses criterion A for testing RPMs, where criterion A is: for specified source strength, we must be at least 95% confident that p ≥ 0.5. To assess criterion A, we consider a distribution-free test and a test relying on assuming the counts Xi have approximately a Poisson distribution. Both test options require tolerance interval construction.

关键词： Poisson Distribution Radiation Portal Monitor Tolerance Interval

Mechanochemical-Assisted Leaching of Lamp Phosphors： A Green Engineering Approach for Rare-Earth Recovery

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Engineering 2018年第3期4卷 398-405页

作者： Steff Van Loy Koen Binnemans tom Van Gerven Department of Chemical Engineering KU Leuven Heverlee B-3001 Belgium Department of Chemistry KU Leuven Heverlee B-3001 Belgium

Rare-earth elements （REEs） are essential metals for the design and development of sustainable energy applications, Recycling these elements from waste streams enriched in them is crucial for securing an independent future supply for sustainable applications, This study compares the mechanisms of mechan- ical activation prior to a hydrometallurgical acid-leaching process and a solvometallurgical mechanochemical leaching process for the recovery of REEs from green lamp phosphor, LaPO4：Ce3＋, Th3＋, After 60 min of processing time, the REE leaching rates showed a significant enhancement of 60% after cycled mechanical activation, and 98% after the combined mechanochemical leaching process, High-resolution transmission electron microscopy （HR-TEM） imaging disclosed the cause for the improved REE leaching rates： The improved leaching and leaching patterns could he attributed to changes in the crystal morphology from monocrystalline to polycrystalline, Reduction of the crystallite size to the nanoscale in a polycrystalline material creates irregular packing of chemical units, resulting in an increase in defect-rich grain boundaries in the crystals, which enhances the leaching process, A solvometallurgical method was developed to combine the mechanical activation and leaching process into a single step, which is beneficial for operational cost, This results in an efficient and simple process that provides an alternative and greener recycling route for lamp phosphor waste,

关键词： Mechanochemistry Rare-earth elements Lamp phosphor waste Ball-milling Solvometallurgy

SHui, an EU-Chinese cooperative project to optimize soil and water management in agricultural areas in the ⅩⅪ century

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International Soil and Water Conservation Research 2020年第1期8卷 1-14页

作者： José A.Gómez Alon Ben-Gal Juan J.Alarcón Gabrielle De Lannoy Shannon de Roos tomá(s)Dostál Elias Fereres Diego S.Intrigliolo Josef Krása Andreas Klik Gunther Liebhard Reinhard nolz Aviva Peeters Elke Plaas John n.Quinton Rui Miao Peter Strauss Weifeng Xu Zhiqiang Zhang Funing Zhong David Zumr Ian C.Dodd Institute for Sustainable Agriculture IASCSICAvda Menendez Pidal S/NCordobaSpain Agricultural Research Organization Gilat Research CenterIsrael Centro de Edafología y Biología Aplicada Del Segura(CSIC) Dept.RiegoMurciaSpain Department of Earth and Environmental Sciences KU LeuvenHeverleeBelgium Czech Technical University in Prague Faculty of Civil Engineering.CVUTPragueCzech Republic Agronomy Department University of CordobaCordobaSpain University of Agricultural Sciences Vienna(BOKU) ViennaAustria TerraVision Lab Midreshet Ben-GurionIsrael Georg-August-Universitat Gottingen Germany Centre for Sustainable Agriculture Lancaster Environment CentreLancaster UniversityUK Center for Plant Water-Use and nutrition Regulation and College of Life Sciences Joint International Research Laboratory of Water and Nutrient in CropsFujian Agriculture and Forestry UniversityFuzhouChina Institute for Land and Water Management Research Federal Agency for Water ManagementPetzenkirchenAustria College of Soil and Water Conservation Beijing Forestry UniversityBeijingChina College of Economics and Management Nanjing Agricultural UniversityNAUNanjingChina

This article outlines the major scientific objectives of the SHui project that seeks to optimize soil and water use in agricultural systems in the EU and China,by considering major current scientific challenges in this ***(for Soil Hydrology research platform underpinning innovation to manage water scarcity in European and Chinese cropping systems)is large cooperative project that aims to provide significant advances through transdisciplinary research at multiple scales(plot,field,catchment and region).This paper explains our research platform of long-term experiments established at plot scale,approaches taken to integrate crop and hydrological models at field scale;coupled crop models and satellite-based observations at regional scales;decision support systems for specific farming situations;and the integration of these technologies to provide policy recommendations through socio-economic analysis of the impact of soil and water saving *** also outlines the training of stake-holders to develop a basic common curriculum despite the subject being distributed across different disciplines and *** such,this article provides a review of major challenges for improving soil and water use in EU and China as well as information about the potential to access information made available by SHui,and to allow others to engage with the project.

关键词： Yield Sustainability Cropping Cooperation

Utilization of Diagnostic Imaging in Dental and Maxillofacial Trauma in Selected Kenyan Hospitals

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Open Journal of Stomatology 2020年第5期10卷 61-73页

作者： Eunice n. Kihara tom J. Ochola Evelyn G. Wagaiyu Mark L. Chindia Department of Oral & Maxillofacial Surgery University of Nairobi Nairobi Kenya Department of Periodontology/Community and Preventive Dentistry University of Nairobi Nairobi Kenya

Background: Globally, much has changed in the imaging modalities available to investigate maxillofacial trauma. nevertheless, the regional practice patterns are highly influenced by availability, affordability and accessibility of imaging services as well as competence in interpreting radiological images and the practice of defensive medicine. The aim was to assess the use of maxillofacial trauma imaging modalities as well as to document patterns of skeletal injuries at selected government-sponsored health facilities in Kenya. Material and Methods: A cross sectional study, done in three health facilities. Results: There were 137 (81.5%) males and 31 (18.5%) females with a mean of 27.73 ± 9.86 years. Commonest aetiology of trauma was interpersonal violence (80, 47.62%) and road traffic crashes (63, 37.50%). The total number of radiological examinations was 250 with a mean of 1.49 ± 0.99 examinations per patient. Plain film radiographs were more (210, 84%) than computed tomographic scans (39, 15.6%). Dental panoramic technique was the most (104, 61.9%) popular. Most participants experienced isolated fractures to the mandible (99, 58.9%) and midface (28, 16.7%). Conclusion: Dental panoramic radiography remained the imaging of choice for mandibular fractures which had the commonest occurrence. There is a shift from the traditional conventional skull radiography to computed tomography in the diagnosis of midfacial fractures. Judicious utilization and prompt provision of affordable services in dental panoramic and computed tomographic scanning at the study centers and other upcoming health facilities are paramount in ensuring timely diagnosis and management of maxillofacial injuries in Kenya.

关键词： Maxillofacial Radiology Facial Trauma Imaging

Salivary Gland Choristoma of the Middle Ear and Review of the Literature

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International Journal of Otolaryngology and Head & neck Surgery 2013年第6期2卷 215-220页

作者： Serafín Sánchez Gómez Juan Manuel Maza Solano José Ramón Armas Padrón Francisco Refolio Sánchez tomás Francisco Herrero Salado Virgen Macarena University Hospital Seville Spain

Conductive hearing loss due to middle ear masses is uncommon and usually diagnosed after biopsy. We present a case of a permanent facial palsy occurred following an uneventful biopsy during an exploratory tympanotomy in a salivary gland choristoma of the middle ear. Most salivary gland choristomas have been found in the head and neck. Its location in the ear is extremely rare, and thus we present the 38th case in English and non-English literature from the first publication by Taylor in 1961. Complete surgical removal of salivary gland choristomas of the middle ear is indicated when may not result in permanent damage to the facial nerve. Only biopsy and observation are recommended when the mass is intimately associated with the facial nerve or there are unsafe facial nerve abnormalities. Although the facial nerve is involved in 40% of cases, transient or even permanent facial palsies are exceptional. The reactivation of latent herpes virus in the facial canal may be involved in facial palsy’ etiology following minimal and uneventful middle ear surgery like a biopsy rather than nerve injury related to facial canal malformations.

关键词： Salivary Gland Choristoma Middle Ear Facial Palsy Herpesvirus Reactivation

Time-domain compact macromodeling of linear photonic circuits via complex vector fitting

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Photonics Research 2019年第7期7卷 86-97页

作者： Yinghao Ye Domenico Spina Dirk Deschrijver Wim Bogaerts tom Dhaene IDLab Department of Information TechnologyGhent University-imecGhentBelgium Photonics Research Group Department of Information TechnologyGhent University-imecGhentBelgium The Center for nano-and Biophotonics(nB-Photonics) GhentBelgium

In this paper, a novel baseband macromodeling framework for linear passive photonic circuits is proposed, which is able to build accurate and compact models while taking into account the nonidealities,such as higher order dispersion and wavelength-dependent losses of the circuits. Compared to a previous modeling method based on the vector fitting algorithm, the proposed modeling approach introduces a novel complex vector fitting technique. It can generate a half-size state-space model for the same applications, thereby achieving a major improvement in efficiency of the time-domain simulations. The proposed modeling framework requires only measured or simulated scattering parameters as input,which are widely used to represent linear and passive systems. Three photonic circuits are studied to demonstrate the accuracy and efficiency of the proposed technique.

关键词： Time-domain compact circuits parameters

Physical Characteristics Explain Ball-Carrying Capability in Sub-Elite Rugby Union Players

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Journal of Science in Sport and Exercise 2023年第3期5卷 244-253页

作者： Alexander S.Hart Robert M.Erskine tom J.Mclaughlin David R.Clark School of Sport and Exercise Science Liverpool John Moores UniversityL33AF LiverpoolUK Ealing Trailfinders Rugby Club LondonUK Institute of Sport Exercise and HealthUniversity College LondonLondonUK

Purpose The aims of the present study were two-fold:(i)to investigate the relationship between physical characteristics and the game statistics associated with ball-carrying capability amongst sub-elite rugby union players,and(ii)to predict the level of change in these physical characteristics required to improve the associated game statistic via regression *** Thirty-eight senior professional players(forwards,n=22;backs,n=16)were assessed for body mass(BM),back squat(BS)single-repetition maximum(1RM)normalised to BM(1RM/BM),10 m sprint velocity(S10),10 m sprint momentum(SM10),and the game statistics from 22 games within the 2019/20 RFU Championship *** relationship between these measures and the predicted level of change in a physical measure required to improve the total number of the associated game statistic by one were assessed by Pearson’s correlation coefficient and simple regression *** In forwards,an~11.5%reduction in BM,an~11.8%improvement in BS 1RM/BM,or an~11.5%increase in S10 was required to improve the game statistics associated with ball-carrying *** backs,a~19.3%increase in BM or a~15.6%improvement in SM10 was *** These findings demonstrate that improvements in lower-body relative strength,acceleration performance,and position-specific alterations in body mass are required to maximise the ball-carrying capability and therefore match outcome of sub-elite rugby union players.

关键词： Speed Acceleration Momentum Strength Body mass

Histologically proven hepatic steatosis associates with lower testosterone levels in men with obesity

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Asian Journal of Andrology 2020年第3期22卷 252-257页

作者： Frederique Van de Velde Marlies Bekaert Anne Hoorens Anja Geerts Guy T'Sjoen tom Fiers Jean-Marc Kaufman Yves Van nieuwenhove Bruno Lapauw department of Endocrinology Ghent University Hospital9000 GhentBelgium department of Pathology Ghent University Hospital9000 GhentBelgium Department of Hepathology Ghent University Hospital9000 GhentBelgium Department of Clinical Biology Ghent University Hospital9000 GhentBelgium Department of Gastro-Intestinal Surgery Ghent University Hospital9000 GhentBelgium.

Men with obesity often present with low testosterone(T)and sex hormone-binding globulin(SHBG)*** mechanisms for this have been proposed,but as SHBG is secreted by hepatocytes and sex steroids undergo hepatic metabolization,this study investigates whether severity and histological components of nonalcoholic fatty liver disease(nAFLD)are associated with sex steroid levels in obese *** cross-sectional study included 80 obese men(age:46±11 years;body mass index:42.2±5.5 kg m^-2).Serum levels of total T and estradiol(E.)were measured using liquid chromatography coupled with tandem mass spectroscopy(LC/MS-MS)and SHBG and gonadotropins by *** biopsies were evaluated using ***,and Fibrosis *** with steatohepatitis had similar median(1st quartile-3rd quartile)total T levels(7.6[5.0-11.0]nmol l^-1 vs 8.2[7.2-10.9]nmol l^-1;P=0.147),lower calculated free T(cFT)levels(148.9[122.9-188.8]pmol 1-1 s 199.5[157.3-237.6] pmol l^-1;P=0.006),and higher free E.T ratios(10.0[6.4-13.9]×10^-3 vs 7.1[5.7-10.7]×10^-3;P=0.026)compared to men with only nonalcoholic fatty *** the histological components of *** steatosis was independently associated with total T(r=-0.331.P=0.003)and cFT levels(r=-0.255.P=0.025).Obese men *** have even lower cFT levels compared to those without,an association mainly driven by grade of *** this reflects a subgroup of men with a more severe obesity-related phenotype or results from direct relations between hepatic steatosis and sex steroid metabolism needs further investigation.

关键词： male hypog on adism non alcoholic fatty liver disease obesity sex steroids steatosis testoster one