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| 1 | Modeling study of combustion process of oil shale semicoke in a circulating fluidized bed boiler显示文摘In this paper,the combustion process of oil shale semicoke was investigated by modeling,where intraparticle mass transfer resistance was especially considered.The ash formation and attrition characteristics of oil shale semicoke were also investigated by a laboratory test procedure.The burnout time and residence time of different particle sizes were predicted,and the maximum particle size of which oil shale semicoke could be burned out in a 3 MW circulating fluidized bed boiler was obtained. | Yiqun Huang Man Zhang Junfu Lyu Hairui Yang | 2018 | Carbon Resources Conversion2018，1，3： | 4 |
| 2 | The Portevin-Le Chatelier effect of gradient nanostructured 5182 aluminum alloy by surface mechanical attrition treatment显示文摘Nanocrystalline surface layers and gradient nanostructure in 5182 aluminum alloy have been produced through surface mechanical attrition treatment(SMAT). The results indicate that the gradient nanostructure can not only improve the mechanical properties of 5182 Al alloy, but also has a certain effect on the Portevin-Le Chatelier(PLC) effect. The yield and ultimate tensile strength of 5182 Al alloy with SMAT are significantly improved combining with the decrease of fracture elongation compared with the as-received one. The PLC effect of 5182 Al alloy could be effectively postponed by the formation of gradient nanostructure after SMAT. It leads to the increase of critical strain of the PLC effect, more concentrated distribution of serrated strain, and increase of average stress amplitude in special strain range. The influence of grain size and gradient nanostructure on the PLC effect of 5182 Al alloy was also discussed in detail. Grain refinement could sharply increase the density of dislocations and hinder the movement of dislocations, which results in the decrease of moving speed of dislocations and the more concentrated distribution of solute atoms. The solute atoms would aggregate to form nano precipitates and further impede movement of dislocation. The stronger interaction between the dislocations and the nano precipitates is the main mechanism of postponed PLC effect. | Xiangchen Meng Bei Liu Lan Luo Yan Ding Xi-Xin Rao Bin Hu Yong Liu Jian Lu | 2018 | Journal of Materials Science & Technology2018，34，12： | 4 |
| 3 | Elutriation, attrition and segregation in a conical spouted bed with a fountain confiner显示文摘This study examined elutriation,attrition,and segregation in a conical spouted bed with a fountain confiner and incorporating an open sided draft tube.Fine silica sand with a wide particle size distribution was employed as a model material,operating in both the batch and continuous modes.The use of a fountain confiner is crucial when operating with fine particles,because otherwise the bed rapidly exhibits significant entrainment.The extent of attrition was quantified using a tracing technique based on differently-coloured sand fractions as well as monitoring size distributions by sieving.Particle breakage was found to be the primary attrition mechanism,and the fountain confiner was determined to limit the elutriation of fine particles resulting from breakage.Consequently,only a small fraction of the finest particles were entrained from the bed.The incorporation of a confiner increased operational stability while reducing segregation,especially in the upper half of the bed where the majority of segregation typically occurs.Thus,the bed was perfectly mixed apart from very minimal segregation close to the wall and at the bottom of the contactor.These results provide a basis for the design and operation of larger scale equipment for the continuous drying of materials. | Aitor Pablos Roberto Aguado Jorge Vicente Mikel Tellabide Javier Bilbao Martin Olazar | 2020 | Particuology2020，18，4： | 2 |
| 4 | Influence of Surface Nanocrystallization on Ti Ion Implantation of Pure Iron显示文摘In order to increase the depth or concentration of Ti ion implantation of pure iron, the surface mechanical attrition treatment(SMAT), which can fabricate a nanometer-grained surface layer without porosity and contamination in a pure iron plate, was used before ion implantation. Ti ion was implanted into the SMA treated sample and coarse-grained counterpart by using a metal vapor vacuum arc source implanter. The changing of depth and concentration of Ti was studied in a function of implantation time.By optical microscopy, transmission electron microscopy and X-ray diffraction, the grain size of the nano structured surface was studied. Micro-hardness, friction and wear behavior of nano surface layers were studied. By energy dispersive X-ray spectroscopy and Auger electron spectroscopy, the chemical composition and concentration of Ti ion in the surface implantation layer were studied. Experimental results showed that the concentration of Ti increased dramatically compared with untreated coarsegrained samples, which is attributed to the existence of higher density of defects(supersaturated vacancies, dislocations, non-equilibrium grain boundaries etc.) and compression stress field in the SMA treated nanocrystallined surface layer. The interaction between the defects and the implanted solute atoms leads to the increment of solid solubility. But the implantation depth showed inconspicuous change. It is shown that the ion range is just relevant to the energy and mass of the ion, dose of injection,the mass and density of target material. | Xu Li Yanli An Yinghui Wei Huayun Du Lifeng Hou Chunli Guo Hongbo Qu Yide Wang | 2015 | Journal of Materials Science & Technology2015，31，3： | 2 |
| 5 | Thermal stability of nanocrystalline layer prepared by surface mechanical attrition in 0Cr18Ni9Ti stainless steel显示文摘By means of surface mechanical attrition (SMA), a nanostructured surface layer was formed on a 0Cr18Ni9Ti austenite stainless steel plate. A strain-induced martensite transformation was observed during SMA treatment, and a single magnetic martensite phase layer with thickness of about 30 μm was gotten. The grain growth and phase transformations in the nanocrystalline layer are investigated during heating. The grain growth exponent for nanocrystalline polycrystalline steel is estimated. The kinetics mechanism governing the grain growth in the nanocrystalline layer is discussed. The martensite in the surface layer is quite stable and the temperature at which the reverse transformation of martensite to austenite starts during heating is about 500 ℃. | WANG Hong-bin WU Xiao-chun XU Ling-yun | 2004 | 中国有色金属学会会刊:英文版2004，14，z1： | 1 |
| 6 | English Language Attrition Among EFL Learners in Terms of Writing Skills显示文摘This study aims to identify if participants experience attrition in writing skills after two years' nonuse of English.70 participants took the tests of writing.A questionnaire was administered to the 70 participants and it included numerous variables that relate to language attrition such as motivation and social activities.The data collected from the tests and questionnaire were analyzed via SPSS.Cronbach's alpha and Many Facets Rasch Model were used to validate the construct and external reliability.The findings showed that participants experienced an overall statistically significant level of attrition in writing skills.Additionally,the specific skills of pertinence,coherence,clarity but excluding grammar,were seen to experience significant attrition over the two years' period.Participants showed a lower level of positive motivation and less social activities for learning English language during the two years' nonuse than before the two years' nonuse of English and this could have contributed to the writing attrition. | 曹海英 | 2012 | 海外英语2012，，1X： | 1 |
| 7 | Study on the friction and wear properties of the surface nanocrystallized 1.0C-1.5Cr steel induced by the surface mechanical attrition treatment显示文摘Nano-structured layers are fabricated on the surface of 1.0C-1.5Cr steel by using the surface mechanical attrition treatment(SMAT)technology,and the microstructures of the surface nano-crystallization layers are characterized by means of X-ray diffraction(XRD)and transmission electron microscopy(TEM).The friction and wear properties are also investigated by a UMT-2 friction and wear tester.Experimental research has indicated that the average diameter of nanocrystalline grains in the surface layer after being treated for 15 min is in the range of 10-20 nm,and ferrite and cementite grains can not be identified by their morphologies.The wear-resistance of the specimen treated for 15 min has been doubled,compared with that of the matrix due to the grain refinement to a nano-sized scale.The lowest friction coefficient is 0.27,which is for the specimen treated for 30 min,resulting from the dissolution of the cementite phase and the formation of a relative homogenous structure.The SMAT technique for enhancing the wear-resistance of the 1.0C-1.5Cr steel has an optimum processing time,which is in the range of 15-30 min.The dominant wear mechanism of the specimen treated for 15 min changes from adhesive wear into particle wear. | ZHANG Junbao1),WANG Aixiang1,2)and ZHANG Yujun1)1)Advanced Technology Division,Research Institute,Baoshan Iron & Steel Co.,Ltd.,Shanghai 201900,China2)School of Materials Science & Engineering,Shanghai Jiao Tong University,Shanghai 200030,China | 2010 | Baosteel Technical Research2010，4，4： | 1 |
| 8 | Study on attrition of spherical-shaped Mo/HZSM-5 catalyst for methane dehydro-aromatization in a gas–solid fluidized bed显示文摘As a potential methane efficient conversion process,non-oxidative aromatization of methane in fluidized bed requires a catalyst with good attrition resistance,especially in the states of high temperature,longtime rapid movement and chemical reaction.Existing evaluation methods for attrition resistance,such as ASTM D5757 and Jet Cup test,are targeted for fresh catalysts at ambient temperature,which cannot well reflect the real process.In this study,spherical-shaped Mo/HZSM-5 catalyst prepared by dipping and spray drying was placed in a self-made apparatus for attrition testing,in which the catalyst attrition under different system temperatures,running time and process factors was investigated with percent mass loss(PML),particle size-mass distribution(PSMD)and scanning electron microscope(SEM).Carbon deposition on the catalyst before and after activation,aromatization and regeneration was analyzed by thermogravimetry(TG),and the attrited catalysts were evaluated for methane dehydro-aromatization(MDA).The results show that the surface abrasion and body breakage of catalyst particles occur continuously,with the increase of system temperature and running time,and make the PML rise gradually.The process factors of activation,aromatization and regeneration can cause the catalyst attrition and carbon deposits,which broaden the PSMD in varying degrees,and the carbon-substances on catalysts greatly improve their attrition resistance at high temperature.Catalyst attrition has a certain influence on its catalytic performance,and the main reasons point to particle breakage and fine powder escape. | Xinzhuang Zhang Yunda Han Dapeng Li Zhanguo Zhang Xiaoxun Ma | 2021 | Chinese Journal of Chemical Engineering2021，34，10： | 1 |
| 9 | Particles attrition of binary mixtures in the coal-fueled chemical looping system based on fluidized bed显示文摘In this work,a reactive air jet attrition device with auto-recording and collection of elutriated fines was developed.Results established insights into the physiochemical interaction and further correlated attrition behaviors between char and oxygen carriers under various operation modes.The attrition rate increased by over 110% upon the introduced CO_(2),which brought in the significant effect of thermo-chemical stress,similarly in effects of the increased char addition ratio and the decreased sizes of char or hematite in different extents.For the char-hematite co-attrition process,the elutriated carbon loss of char with poor mechanical strength was found to be over 10%,while the reactive iron loss of hematite was found to be 6.3%,and was enriched in elutriated fines.The reaction-derived thermochemical stress and the collision-derived mechanical stress jointly controls the particle attrition during the cyclic transformation of oxygen carrier particles in coal-fueled chemical looping fluidization,especially sig-nificant in its reduction stage. | Heyu Li Zhe Sun Yan Cao | 2024 | Particuology2024，86，3： | 0 |
| 10 | Investigation into Phonological Attrition among Beginner Chinese Mandarin Language Learners显示文摘Studying foreign language attrition is important in the context of Chinese language learning because, in light of a growing worldwide interest in learning Chinese languages, language professionals need to understand the complexities of Chinese language acquisition. However, little research exists to date on foreign language attrition among Chinese language learners. In this study, we examined the features of language attrition,especially phonological attrition, among Mandarin learners in a higher educational institution in Brunei Darussalam. Additionally, we sought to test, in a Bruneian context,prominent theories and hypotheses about language attrition, including markedness theory and functional load theory. Our sample consisted of 86 beginner Mandarin students who spoke Malay as their native language and English as the academic language. Participants were 18-20 years old and studied Mandarin formally 4 hours per week for 14 consecutive weeks, during which they were also required to study for 8 hours per week on their own.Subsequently, they took a 3-month break from studying. We tested participants before and after the break and computed descriptive statistics to compare the results of the two tests. Our results showed the greatest attrition rates in tones and special structures of Mandarin, with less attrition in final and initial sounds. We discuss specific phonological findings as they relate to native Malay speakers, and we describe how our findings confirm or contradict,within the Bruneian context, existing theories. We conclude that markedness theory is applicable in our research context, but our findings failed to support functional load theory. | Min Shen | 2017 | 宏观语言学2017，5，1： | 0 |
| 11 | Deformation mechanism and dynamic precipitation in a Mg-7Al-2Sn alloy processed by surface mechanical attrition treatment显示文摘The effect of second phases on the deformation mechanism of as-cast, solution-treated and aged Mg-7Al-2Sn (AT72) alloys during surface mechanical attrition treatment (SMAT) was investigated. Twinning was suppressed in the alloys containing second phases, which can provide nonuniform microstructures and phase boundaries as dislocation sources. Dynamic precipitation in AT72 alloys was studied during SMAT deformation as well.Mg2Sn particles can dynamically precipitate on the surface of all AT72 alloys during SMAT process. The quantity of Mg2Sn particles in the as-cast alloy, which is determined by the initial quantity of second phases, is larger than that of T4 and T6 alloys after the SMAT process. | Xiaoying Shi Yangxin Li Xiaoqin Zeng Yong Liu Bin Chen Jian Lu Dejiang Li | 2019 | Journal of Materials Science & Technology2019，35，7： | 0 |
| 12 | A Tentative Study of Foreign Language Attrition over the Period of Winter Vacation—A Survey of College Students in Yanshan University显示文摘This paper first presents a review of language attrition research with its defi nition and classifi cation. Then, through a survey of college students, the infl uence of shortterm language attrition over the learners' cognition and affection is identifi ed. To decrease the negative factors, some pedagogical implications and suggestions are discussed and provided in the end. | 徐珊 | 2015 | 英语广场(学术研究)2015，，5： | 0 |
| 13 | Teaching Indigenous Knowledge System to Revitalize and Maintain Vulnerable Aspects of Indigenous Nigerian Languages’ Vocabulary:The Igbo Language Example显示文摘The Igbo language curriculum for pupils and students at the primary and secondary levels shows no provision for the teaching of any aspects of Igbo indigenous knowledge systems and this is resulting in the attrition and atrophy of vocabulary items associated with such knowledge systems,especially in the speech of primary and secondary students in urban and semi-urban areas of Igbo speech communities where the practices of the knowledge systems are quite remote.This paper examines the benefits derivable from integrating indigenous Igbo knowledge systems into the Igbo language curriculum(through comprehension passages,practical discussions,excursions,audio-visual materials,dramatization,etc.)for both the senior primary pupils and the secondary school students of Igbo origin in south-eastern Nigeria.The data presented in the study were collected through interviews from selected respondents.The study notes that integrating indigenous Igbo knowledge systems into the Igbo language curriculum of both pupils and students will afford pupils/students the opportunities to:(i)learn the indigenous Igbo knowledge systems and positive attitudes/values embedded in them(ii)learn through the Igbo culture(iii)learn across generations(iv)learn from the‘known’in the Igbo culture to the‘unknown’(v)learn outside the classroom.The paper further highlights sample vocabulary items associated with some indigenous Igbo knowledge systems which students/pupils can learn and familiarize themselves with in contextual usage.The paper concludes that learning through the teaching of the indigenous Igbo knowledge systems will enhance the revitalization,preservation and maintenance of the Igbo language and culture and also encourage intergenerational transfer of the language. | Friday Ude Ogbonna Anyanwu Eunice Osuagwu | 2020 | Language and Semiotic Studies2020，6，2： | 0 |
| 14 | Investigative safety strategies to improve success in drug development显示文摘Understanding and reducing attrition rate remains a key challenge in drug development.Preclinical and clinical safety issues still represent about 40%of drug discontinuation,of which cardiac and liver toxicities are the leading reasons.Reducing attrition rate can be achieved by various means,starting with a comprehensive evaluation of the potential safety issues associated to the primary target followed by an evaluation of undesirable secondary targets.To address these risks,a risk mitigation plan should be built at very early development stages,using a panel of in silico,in vitro,and in vivo models.While most pharmaceutical companies have developed robust safety strategies to de-risk genotoxicity and cardiotoxicity issues,partly driven by regulatory requirements;safety issues affecting other organs or systems,such as the central nervous system,liver,kidney,or gastro-intestinal system are less commonly addressed during early drug development.This paper proposes some de-risking strategies that can be applied to these target organ systems,including the use of novel biomarkers that can be easily integrated in both preclinical and clinical studies.Experiments to understand the mechanisms’underlying toxicity are also important.Two examples are provided to demonstrate how such mechanistic studies can impact drug development.Novel trends in investigative safety are reviewed,such as computational modeling,mitochondrial toxicity assessment,and imaging technologies.Ultimately,understanding the predictive value of non-clinical safety testing and its translatability to humans will enable to optimize assays in order to address the key objectives of the drug discovery process,i.e.,hazard identification,risk assessment,and mitigation. | Franck Atienzar Annie Delaunois Frédéric Brouta Miranda Cornet Renaud Fleurance Helga Gerets Stéphanie Glineur Catrin Hasselgren Andrea Kiessling Andre Nogueira da Costa Marie-Luce Rosseels Karen Tilmant Jean-Pierre Valentin | 2016 | Journal of Medicines Development Sciences2016，2，1： | 0 |
| 15 | Ensemble Classifier-Based Features Ranking on Employee Attrition显示文摘The departure of good employee incurs direct and indirect cost and impacts for an organization.The direct cost arises from hiring to training of the relevant employee.The replacement time and lost productivity affect the running of business processes.This work presents the use of ensemble classifier to identify important attributes that affects attrition significantly.The data consists of attributes related to job function,education level,satisfaction towards work and working relationship,compensation,and frequency of business travel.Both bagging and boosting classifiers were used for testing.The results show that the selected features(nine selected features)achieve the same result as the full features.The selected features are age,income,working years,source of employment,years since last promotion,salary hike,and business travelling frequency.These features were selected using ensemble classifiers.Satisfaction on work and relationship do not appear to be significant attributes in attrition from ensemble classifier’s results. | Yok-Yen Nguwi | 2022 | Journal on Artificial Intelligence2022，4，3： | 0 |
| 16 | Electrochemical and Tribological Behaviour of Ti6Al4V Subjected to the Duplex SMAT/Plasma Nitriding显示文摘In this work,SMAT(surface mechanical attrition treatment)was performed on Ti6Al4V.Plasma nitriding of the SMATed samples was investigated in comparison with coarse-grained samples.The samples were characterized using optic microscope,SEM,TEM and Vickers microhardness tester.The results showed that a significantly thicker compound layer with higher hardness was obtained for the SMATed samples when compared with un-SMATed samples after nitriding.Corrosion resistance of Ti6Al4V in a Ringer’s solution was studied by electrochemical techniques including open circuit potential measurement,potentiodynamic polarization and EIS(electrochemical impedance spectroscopy).Overall,our results identified the beneficial impacts of the duplex SMAT/nitriding treatment on corrosion behaviour of Ti6Al4V.Wear tests were also performed on a ball-on-disc tribometer where the treated samples were rubbed against a 6 mm diameter alumina ball under a normal load of 5 N using Ringer’s solution as lubricant media.The friction coefficient of the SMATed and nitrided samples was reduced compared to the untreated samples.Wear rates demonstrated that SMAT combined with nitriding improved wear resistance of Ti6Al4V alloy. | Jelliti Sami Delphine Retraint | 2018 | Journal of Physical Science and Application2018，8，3： | 0 |
| 17 | Microstructure and Mechanical Properties of Al/Al_4C_3/Al_2O_3 Composite显示文摘MicrostructureandMechanicalPropertiesofAl/Al4C3/Al2O3CompositeJiaDechang,ZhouYuandLeiTingquan(贾德昌)(周玉)(雷廷权)DepartmentofMateri... | 贾德昌 周玉 雷廷权 | 1998 | Rare Metals1998，17，2： | 0 |
| 18 | The Analysis of the Attrition of College Students in Mobile Assisted Language Learning: A Case Study Based on UTAUT Model显示文摘Mobile devices are playing indispensable roles in college students’lives and more and more college students adopt MALL(mobile assisted language learning).However,the student attrition in MALL is rather high compared with traditional classroom learning.This study introduced qualitative method based on UTAUT model,and tried to explain the student attrition in MALL and how to engage college students deeper in MALL. | 孙洋 | 2019 | 海外英语2019，，5： | 0 |
| 19 | DENTAL OCCLUSION STUDY OF YUDEN'S SKULL IN NEOLITHIC AGE显示文摘DENTALOCCLUSIONSTUDYOFYUDEN SSKULLINNEOLITHICAGEXuLin(徐丽丽),SunDelin(孙大麟),PanKefeng(潘可风)(DepartmentofOralAnatomy,SchoolofStoma... | 徐丽丽 孙大麟 潘可风 陈翁良 | 1994 | Medical Bulletin of Shanghai Jiaotong University1994，17，1： | 0 |
| 20 | Investigation of the redox performance of pyrite cinder calcined at different temperature in chemical looping combustion显示文摘As an industrial solid waste,pyrite cinder exhibited excellent reactivity and cycle stability in chemical looping combustion.Prior to the experiment,oxygen carriers often experienced a high temperature calcination process to stabilize the physico-chemical properties,which presented significant influence on the redox performance of oxygen carriers.However,the effect of calcination temperature on the cyclic reaction performance of pyrite cinder has not been studied in detail.In this work,the effect of calcination temperature on the redox activity and attrition characteristic of pyrite cinder were studied in a fluidizedbed reactor using CH_(4) as fuel.A series of pyrite cinder samples were prepared by controlling the calcination temperature.The redox activity and attrition rate of the obtained pyrite cinder samples were investigated deeply.The results showed that calcination temperature displayed significant impact on the redox performance of pyrite cinder.Considering CH_(4) conversion(80%–85%)and attrition resistance,the pyrite cinder calcined at 1050℃ presented excellent redox properties.In the whole experiment process,the CO_(2) selectivity of the pyrite cinder samples were not affected by the calcination temperature and were still close to 100%.The results can provide reference for optimizing the calcination temperature of pyrite cinder during chemical looping process. | Zhong Ma Guofu Liu Hui Zhang Yonggang Lu | 2022 | Chinese Journal of Chemical Engineering2022，35，8： | 0 |
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