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Chemical Research in Chinese Universities 2002年第2期18卷 192-195页

作者： JIAO Qing ze ZHAO Yun ZHANG Yi qing evans DG DUAN Xue ZHOU Zi-niu The Key Laboratory of Science and Technology of Controllable Chemical Reactions Ministry of EductionBeijing University of Chemical TechnologyBeijing 100029P.R.China Yixing Auxiliary Chemicals Plant Jiangsu 214262P.R.China

The reaction of ethanol with propylene oxide over calcined layered double hydroxides(CLDH) was investigated. The results show that CLDH has a good activity and a good selectivity, but the activity and the selectivity of CLDH decrease when CLDH reforms LDH- the so called 'memory effect'. The influence of the 'memory effect' on the CLDH returning to LDH was studied by the hydration reaction. It is shown that the 'memory effect' is not complete, and the decreases of the Mg/Al molar ratio of LDH and the crystallite size due to the increase of the hydration reaction time result in the drop of the activity and the selectivity.

关键词： Ethanol, Propylene oxide Calcined layered double hydroxide 'Memory effect' Hydration

Flow of Steel in Mold Region During Continuous Casting

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Journal of Iron and Steel Research International 2007年第2期14卷 30-35,41页

作者： ZHANG Xing-guo ZHANG Wen-xiao JIN Jun-ze J. W. evans Research Center of Foundry Engineering Dalian University of Technology Dalian 116023 Liaoning China Department of Material Science and Engineering University of California at Berkeley Berkeley CA94720 USA

The particle image velocimetry （PIV） technique was used to study the fluid flow phenomena that occurred during continuous casting, using a water model with dimensions of 1 840mm× 280 mm. Two types of solidified shells, i. e. , the smooth type and the coarse type, were used to characterize the dendrite in order to simulate different liquid-solid interfacial conditions. The influence of the nozzle angle and the immersion depth of nozzle, as well as the casting speed on the flow behavior was investigated quantitatively. The results were as follows：（1） There are two large recirculations above and below the fluid jet in the mold, respectively, under the smooth interface condition. However, in the case of the dendrite solidified shell, it was found that the flow velocity of the fluid decreased and more smaller vortices appeared in the upper region of the mold. （2） The angle and the immersion depth of nozzle are two important factors affecting the flow pattern, and they are also capable of bringing about the change in the flow direction. （3） The higher the casting speed, the higher are the jet stream and the impacting point on the narrow face. However, the high casting speed causes serious fluctuation of the meniscus, and correspondingly leads to various defects.

关键词： particle image velocimetry continuous casting steel fluid flow

Structure and Combustion Characteristics of Methane/Air Premixed Flame under the Action of Wall

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Energy Engineering 2021年第4期118卷 1135-1154页

作者： Feiyang Li Jianfeng Pan Chenxin Zhang evans K.Quaye Xia Shao School of Energy and Power Engineering Jiangsu UniversityZhenjiang212013China

In order to obtain the combustion characteristics of the CH4/Air premixed flame under the action of the wall interaction,a study on the impact of the jet flame on the wall at different separation distances was carried *** separation distance from the burner outlet to the lower surface of the wall is changed and the flame structure is obtained through *** temperature,velocity and reaction rate are obtained through numerical simulation,and the law of flame characteristics change is obtained through *** results show that as the separation distance increases,the premixing cone inside the flame gradually changes from a horn shape to a complete cone shape and the length of the premixing cone profile ***,the peak temperature and velocity of the mixture in the axial direction gradually increase,and the temperature and velocity in the radial direction first increase and then *** temperature gradient and velocity reach the maximum when the separation distance is 11 *** peaks of reactants(CH_(4))net reaction rate intermediate products(CO)and products(CO_(2),H_(2)O)on the axis and the axial distance corresponding to the peaks increase *** chemical reaction rate near the wall also gradually decreases with the increase of the separation distance.

关键词： Flame-wall interaction separation distance flame structure air flow temperature flow velocity reaction rate

Transition clinic attendance is associated with improved beliefs and attitudes toward medicine in patients with inflammatory bowel disease

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World Journal of Gastroenterology 2017年第29期23卷 5405-5411页

作者： Nancy Fu Kevan Jacobson Andrew Round Kathi evans Hong Qian Brian Bressler Division of Gastroenterology Department of Medicine University of British Columbia Division of Gastroenterology Hepatology and Nutrition Department of Pediatrics University of British Columbia Faculty of Medicine University of British Columbia Centre of Health Evaluation and Outcome Sciences

To evaluated the differences in knowledge, adherence, attitudes, and beliefs about medicine in adolescents with inflammatory bowel disease (IBD) attending transition clinics. METHODSWe prospectively enrolled patients from July 2012 to June 2013. All adolescents who attended a tertiary-centre-based dedicated IBD transition clinic were invited to participate. Adolescent controls were recruited from university-affiliated gastroenterology offices. Participants completed questionnaires about their disease and reported adherence to prescribed therapy. Beliefs in Medicine Questionnaire was used to evaluate patients’ attitudes and beliefs. Beliefs of medication overuse, harm, necessity and concerns were rated on a Likert scale. Based on necessity and concern ratings, attitudes were then characterized as accepting, ambivalent, skeptical and indifferent. RESULTSOne hundred and twelve adolescents were included and 59 attended transition clinics. Self-reported adherence rates were poor, with only 67.4% and 56.8% of patients on any IBD medication were adherent in the transition and control groups, respectively. Adolescents in the transition cohort held significantly stronger beliefs that medications were necessary (P = 0.0035). Approximately 20% of adolescents in both cohorts had accepting attitudes toward their prescribed medicine. However, compared to the control group, adolescents in the transition cohort were less skeptical of (6.8% vs 20.8%) and more ambivalent (61% vs 34%) (OR = 0.15; 95%CI: 0.03-0.75; P = 0.02) to treatment. CONCLUSIONAttendance at dedicated transition clinics was associated with differences in attitudes in adolescents with IBD.

关键词： Inflammatory bowel disease Adolescents Transition Beliefs Knowledge Attitudes

Extrusion Freeforming of Millimeter-Wave Electromagnetic Bandgap (EBG) Photonic Crystals

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Tsinghua Science and Technology 2009年第S1期14卷 168-174页

作者：吕雪松 LEE Yoonjae evans Julian R G PARINI Clive G Department of Chemistry University College London 20 Gordon Street London WC1H 0AJ UK Department of Electronic Engineering Queen Mary University of London Mile End Road London E1 4NS UK

Extrusion freeforming can be used for the rapid prototyping of millimeter-wave electromagnetic bandgap (EBG) structures. In this work, an alumina-polymer paste with a relatively high volatility solvent (propanol) was used and the characteristics of the ceramic paste, particularly the rheological features are described. The advantage of high volatility solvent is that the viscosity and elastic modulus of the paste are increased sharply as the solvent evaporates. Thus, the rigidity of the extruded filament is quickly increased as a small amount of solvent evaporates. Finally, by employing this procedure, different EBG structures such as 2-D, 3-D woodpile and aperiodic structures were fabricated and their bandgaps were measured. The experimental results show that extrusion freeforming is a relatively simple and easy method to fabricate these woodpile structures with a bandgap in the 90-110 GHz region.

关键词： extrusion freeforming paste rheology electromagnetic bandgap (EBG) crystal

A call for international research on COVID-19-induced brain dysfunctions

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National Science Review 2021年第12期8卷 13-14页

作者： Pedro A.Valdes-Sosa Alan C.evans Mitchell J.Valdes-Sosa Mu-ming Poo Global Brain Consortium University of Electronic Sciences and Technology of China (UESTC) Cuban Neuroscience Center (CNEURO) Cuban Academy of Sciences Global Brain Consortium Royal Society of CanadaMc Gill Center for Integrative Neuroscience Mc Gill University Center for Excellence in Brain Science and Intelligence Technology Institute of NeuroscienceChinese Academy of Sciences

The COVID-19 pandemic, still raging worldwide, imposes staggering human and economic costs. These will only increase as many convalescent patients suffer consequences for many *** the virus can target multiple organ s...

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Evolving management of metaplasia and dysplasia in Barrett's epithelium

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World Journal of Gastroenterology 2016年第47期22卷 10316-10324页

作者： Richard PT evans Moustafa Mabrouk Mourad Simon G Fisher Simon R Bramhall Department of Surgery the Wye Valley NHS Trust

Oesophageal cancer affects more than 450000 people worldwide and despite continued medical advancements the incidence of oesophageal cancer is increasing. Oesophageal cancer has a 5 year survival of 15%-25% and now globally attempts are made to more aggressively diagnose and treat Barrett's oesophagus the known precursor to invasive disease. Currently diagnosis the of Barrett's oesophagus is predominantly made after endoscopic visualisation and histopathological confirmation. Minimally invasive techniques are being developed to improve the viability of screening programs. The management of Barrett's oesophagus can vary greatly dependent on the presence and severity of dysplasia. There is no consensus between the major international medical societies to determine and agreed surveillance and intervention pathway. In this review we analysed the current literature to demonstrate the evolving management of metaplasia and dysplasia in Barrett's epithelium.

关键词： Barrett’s Oesophagus Dysplasia Metaplasia Oesophageal cancer

Stress corrosion cracking behaviors of RE-containing ME21 magnesium alloy processed by equal-channel angular pressing

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Journal of Rare Earths 2019年第1期37卷 88-94,M0005页

作者： Jinghua Jiang Qiuyuan Xie Mingshan Qiang Aibin Ma evans-Kwesi Taylor Yuhua Li Dan Song Jianqing Chen College of Mechanics and Materials Hohai University Suqian Institute Hohai University

A commercial as-cast ME21 magnesium alloy containing rare-earth (RE) element was processed by equalchannel angular pressing to obtain fine-grained micro structure. Stress corrosion cracking (SCC) behaviors of the fine-grained samples were studied by slow-strain-rate testing in air, distilled water and Hanks’solution at the strain rate of 1×10^(-6) s^(-1). All samples show a relatively low SCC sensitivity in distilled water but a great SCC tendency in Hanks’ solution. The microscopic observations of the fracture surfaces and the side surfaces reveal obvious active anodic dissolution and hydrogen embrittlement cracks, which indicate the higher SCC susceptibility in Hanks'solution. The fine-grained microstructure with more crystal defects promotes the passivation process of the oxide film and restrains the hydrogen induced cracking of the ME21 magnesium alloy, leading to the higher general corrosion resistance as well as SCC resistance.

关键词： Magnesium alloy Stress corrosion cracking Equal-channel angular pressing Corrosion medium Fine-grained Rare earths

Education programs for people living with chronic pain:a scoping review

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Frontiers of Nursing 2020年第4期7卷 307-319页

作者： Hai-Ying Wang Carol Grech David evans Rasika Jayasekara Family Health Golden Grove 205 The Golden WayGolden GroveSouth Australia 5125Australia School of Nursing&Midwifery University of South AustraliaAustralia

Objective:The aim of this scoping review was to provide evidence for health practitioners to improve patient education practice for chronic pain ***:A scoping review was guided by Arksey and O’Malley’s(2005)1 five-stage framework,investigated contemporary patient education programs(2007–2018)for chronic pain management in education content,formats of delivery,and tools used for *** analysis and description were used for the outcome ***:Seven quantitative studies were *** content consisted of General information,Cognitive behavior therapy(CBT),Self-management,and Pain neurophysiology(PN).Education delivery formats varied from workbook to workbook,face-toface,online,when given for a group or individual or in a combined *** total,19 tools were reported for the evaluation of the education ***:There is a variety in the education content and the delivery *** majority of programs showed effectiveness in patients’chronic pain management based on their selected evaluation *** review showed that patient education programs can be useful in chronic pain *** effectiveness of patient education programs focuses on the improved patients’physical function and quality of life rather than the cessation of pain only.

关键词： patient education chronic pain management scoping review taxonomy pain patient education

The Voisey's Bay Ni-Cu-Co Sulfide Deposit, Labrador, Canada: Emplacement of Silicate and Sulfide-Laden Magmas into Spaces Created within a Structural Corridor

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西北地质 2012年第4期45卷 17-38页

作者： Peter C.Lightfoot Dawn evans-Lamswood Robert Wheeler Vale ExplorationHighway 17 WestSudburyOntarioP0M 1N0Canada Vale Newfoundland and Labrador Limited Bally Rou Place280Torbay RoadSuite W200St.John'sNewfoundlandA1A 3W8Canada

The Voisey's Bay Ni-Cu-Co sulfide deposit is hosted in a 1.34 Ga mafic intrusion that is part of the Nain Plutonic Suite in Labrador, *** Ni-Cu-Co sulfide mineralization is associated with magmatic breccias that are typically contained in weakly mineralized olivine gabbros, troctolites and ferrogabbros, but also occur as veins in adjacent *** mineralization is associated with a dyke-like body which is termed the feeder *** dyke connects the shallow differentiated Eastern Deeps chamber in the east to a deeper intrusion in the west termed the Western Deeps *** the conduit is connected to the Eastern Deeps Intrusion, the Eastern Deeps Deposit is developed at the entry line of the dyke along the steep north wall of the Eastern Deeps *** Eastern Deeps Deposit is surrounded by a halo of moderately to weakly mineralized Variable-Textured Troctolite (VTT) that reaches a maximum thickness above the ENE-WSW axis of the Eastern Deeps Deposit. At depth to the west, the conduit is adjacent to the south side of the Western Deeps Intrusion, where the dyke and intrusion contain disseminated magmatic sulfide *** Reid Brook Zone plunges to the east within the dyke, and both the dyke and adjacent paragneiss are *** Ovoid Deposit comprises a bowl-shaped body of massive sulfide where the dyke widens near to the present-day *** is not clear whether this deposit was developed as a widened-zone within the conduit or at the entry point into a chamber that is now lost to erosion. The massive sulfides and breccia sulfides of the Eastern Deeps are petrologically and chemically different when compared to the disseminated sulfides in the VTT; there is a.marked break in Ni tenor (Ni content in 100% sulfide, abbreviated to [Ni]100) and Ni/Co of sulfide between the *** boundary of the sulfide types is often marked by strong sub-horizontal alignment of heavily digested and metamorphosed paragneiss fragments, developm

关键词： Voisey’s Bay Ni-Cu-Co sulfide deposit Labrador Canada