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多道次等径通道挤压后TWIP钢的本构模型（英文）

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材料热处理学报 2017年第2期38卷 185-190页

作者：王雷 BENITO j A CALVO j CABRERA j M 西安石油大学材料科学与工程学院陕西西安710065 加泰罗尼亚理工大学工业工程学院材料科学与冶金工程系ETSEIB 加泰罗尼亚理工大学工业工程学院材料科学与冶金工程系EUETIB 曼雷萨科技中心

研究了通过等径通道挤压技术加工后的诱导孪晶塑性变形钢(TWIP钢)的力学性能,并且通过Ludwik,Hollomon以及Swift三种本构模型对拉伸真实应力应变曲线进行了拟合。实验结果表明:随着挤压道次的增加,屈服强度以及极限抗拉强度不断升高,而... 详细信息

研究了通过等径通道挤压技术加工后的诱导孪晶塑性变形钢(TWIP钢)的力学性能,并且通过Ludwik,Hollomon以及Swift三种本构模型对拉伸真实应力应变曲线进行了拟合。实验结果表明:随着挤压道次的增加,屈服强度以及极限抗拉强度不断升高,而塑性,抗拉韧性不断下降。Ludwik,Hollomon以及Swift三种本构模型对于真实应力应变曲线的拟合程度较好,并且本文给出了各模型中的拟合参数。拟合参数中,本文着重讨论了应变硬化系数n随着挤压道次的升高而降低的原因。

关键词： TWIP钢等径通道挤压技术(ECAP) 力学性能本构模型

等径通道挤压后TWIP钢力学性能以及微观组织演化（英文）

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材料热处理学报 2016年第11期37卷 86-95页

研究了等径通道挤压技术对于一种低碳高锰孪晶诱导塑性变形(TWIP)钢力学性能,微观结构以及织构性能的影响。微拉伸实验结果表明:TWIP钢维氏硬度值,屈服强度和抗拉强度随挤压道次增长不断升高,而塑性则下降。通过EBSD分析,结果表明经等... 详细信息

研究了等径通道挤压技术对于一种低碳高锰孪晶诱导塑性变形(TWIP)钢力学性能,微观结构以及织构性能的影响。微拉伸实验结果表明:TWIP钢维氏硬度值,屈服强度和抗拉强度随挤压道次增长不断升高,而塑性则下降。通过EBSD分析,结果表明经等径通道挤压,平均晶粒尺度由原始状态下的199.6μm减小到不足1μm,孪晶比例也随之下降。关于ECAP挤压后的织构演化,EBSD结果表明原始状态下的主导织构为Goss和Brass,而在挤压后,逐渐由一道次的A*1和A*2织构向多道次的B/B·织构过渡。这表明了多道次挤压后材料呈现了更加稳定的微观结构。

关键词： TWIP钢等径通道挤压技术(ECAP) 微观结构织构力学性能

AZ31镁合金初始动态再结晶的临界条件研究

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稀有金属材料与工程 2007年第12期36卷 2080-2083页

作者：黄光杰钱宝华汪凌云 j.j.jonas 重庆大学重庆400044 McGill大学

为确定AZ31镁合金初始动态再结晶的临界条件或临界应变,通过在变形温度范围473～623K、应变速率范围0.001～1s-1条件下进行等温压缩试验,利用所得数据并采用单参数方法,建立起AZ31镁合金初始动态再结晶的临界条件,即临界应变(εc)与变... 详细信息

为确定AZ31镁合金初始动态再结晶的临界条件或临界应变,通过在变形温度范围473～623K、应变速率范围0.001～1s-1条件下进行等温压缩试验,利用所得数据并采用单参数方法,建立起AZ31镁合金初始动态再结晶的临界条件,即临界应变(εc)与变形条件(引入温度补偿应变速率因子即Zener-Hollomon参数)的定量关系,并对不同应变下合金微观组织的演变规律进行了研究。

关键词：镁合金初始动态再结晶临界应变微观组织

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Inactivation of OslRX10 Leads to Decreased Xylan Content in Rice Culm Cell Walls and Improved Biomass Saccharification

作者： (美)j.·邓恩 (英)j. B.·伯里

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Molecular Plant 2013年第2期6卷 570-573页

作者： Xuewei Chen Miguel E. Vega-sanchez Yves Verhertbruggenb Dawn Chiniquy Patrick E. Canlas Alexandra Fagerstrom Lina Prak Ulla Christensen Ai Oikawa Mawsheng Chern Shimin Zuo Fan Lin Manfred Auer William G.T. Willats Laura Bartley jesper Harholt Henrik V. Scheller Pamela C. Ronald Department of Plant Pathology and The Genome Center University of California Davis CA 95616 USA joint BioEnergy Institute Emeryville CA 94608 USA Rice Research Institute Sichuan Agricultural University at Wenjiang Wenjiang Chengdu 611130 China Physical Biosciences Division Lawrence Berkeley National Laboratory Berkeley CA 94720 USA Department of Plant and Environmental Sciences Faculty of Science University of Copenhagen DK-1871 Frederiksberg Denmark Department of Botany and Microbiology University of Oklahoma Norman OK 73019 USA Department of Plant and Microbial Biology University of California Berkeley CA 94720 USA

Dear Editor, Xylan polysaccharides constitute the major non-cellulosic components in secondary cell walls of dicots and in both primary and secondary cell walls of grasses （Scheller and Ulvskov, 2010）. Xylan is composed of a linear backbone of 13（1-4）-linked xylose （Xyl）. In grasses, the xylan backbone is substituted with 03-1inked and 02-1inked arabinose residues and, to a lesser extent, a（1-3）-Iinked glucuronic acid residues.

关键词： Cell wall xylan wall Culm Inactivation Secondary batteries Residues Saccharification cellulose microfibrils Grasses

An economic analysis of varicella immunization in the Singapore military

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journal of Medical Colleges of PLA(China) 2016年第1期31卷 43-50页

作者： jake j.K.Goh Marc Ho W.M.Koh Vernon j.Lee Specialist Medicine Centre AFPN 0047 27 Medical Drive #08-01 Singapore 117510 Singapore National University of Singapore MD3 16 Medical Drive Singapore 117597 Singapore

Background:Varicella outbreaks occur frequently in closed environments such as those of *** paper compares the economic outcomes of varicella vaccination in enlisted servicemen without prior reported varicella infection or ***:We analyzed the economic outcomes of a varicella vaccination program on all enlisted servicemen without prior reported varicella infection or vaccination in the Singapore Armed Forces(SAF) between December 11,2010–December 20,2013,compared with the previous program of varicella vaccination only for selected personnel between December 1,2007–December 10,***:In the at-risk population of all active SAF servicemen,the program of varicella vaccination for all servicemen without prior reported varicella infection or vaccination upon enlistment would save 72.0 work days per 1000(95% CI:61.2-82.9),valued at SG$6,544 per 1000(95% CI:6,524-6,564),i.e.,costing SG$91.5 per work day saved(95% CI:78.7-107.3).This also results in a reduction of 2.7 varicella cases per 1000 and 5.43 outbreaks per 10000,or a total savings of SG$1,695 per 1000(95% CI:–2,730-6,834),taking into account the cost of work days lost over a three-year period,compared with the previous regime of vaccinations only for selected ***:The varicella vaccination strategy targeting all enlisted servicemen without prior reported varicella infection or vaccination is able to prevent varicella infections and outbreaks,thus reducing absenteeism and days lost.

关键词： Varicella Vaccination Military Singapore Economic analysis

Tree species composition and diversity in montane forests of Garhwal Himalaya in relation to environmental and soil properties

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journal of Mountain Science 2020年第12期17卷 3097-3111页

作者： Dinesh Singh RAWAT P.TIWARI Sudipta Kumar DAS j.K.TIWARI Department of Botany&Microbiology HNB Garhwal UniversitySrinagar(Garhwal)-246174UttarakhandIndia Central National Herbarium Botanical Survey of IndiaHowrah-711103West BengalIndia

The montane forests of Garhwal Himalaya were investigated for tree species composition and diversity in relation to environmental and edaphic variables.A stratified random sampling approach was adopted to collect the field data from each forest.A total of 39 tree species belonging to 31 genera and 23 families were recorded from the sampling area(6 forest stands ×10 plots in each).Lauraceae with 5 species was the largest family while Quercus(4 species) emerged as the largest ***-area curve(asymptote) predicted more species than the observed number of *** analysis has shown that the two Abies pindrow dominant forest stands had the highest similarity in tree species *** tree stem density ranged from 540-1170 ha-1,basal area 23.01-55.94 m^2 ha-1,ShannonWiener diversity index 1.69-2.49,evenness index0.42-0.74,beta diversity 0.40-0.82 and similarity index 0.17-0.54 in the six studied ***-way indicator species analysis(TWINSPAN) identified four distinct tree communities in the study area with Daphniphyllum himalayense,Abies pindrow,Quercus oblongata,and Pinus roxburghii as indicator species of corresponding *** correspondence analysis(CCA) ascertained the TWINSPAN results and revealed the relation of tree species with environmental and edaphic *** phytosociological attributes of tree species varied from one forest stand to another;however,the tree species richness,density,and diversity peaked at intermediate elevation on the north *** reveal that tree composition and diversity in the montane forests of Garhwal Himalaya are influenced by both environmental(elevation and slope aspect)and soil variables(texture,water holding capacity,moisture content,available N,exchangeable P,and pH).This study will help in understanding the forest distribution across the western Himalaya,guiding the conservationists and policymakers in carrying out conservation-related management activities,designing the long-

关键词： Diversity Tree species Montane forests Soil properties Western Himalaya

Parametric study on smoothed particle hydrodynamics for accurate determination of drag coefficient for a circular cylinder

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Water Science and Engineering 2017年第2期10卷 143-153页

作者： Maziar Gholami Korzani Sergio A. Galindo-Torres Alexander Scheuermann David j. Williams School of Civil Engineering The University of Queensland St Lucia Brisbane QLD 4072 Australia School of Mathematics and Physics The University of Queensland St Lucia Brisbane QLD 4072 Australia

Simulations of two-dimensional(2D) flow past a circular cylinder with the smoothed particle hydrodynamics(SPH) method were conducted in order to accurately determine the drag coefficient. The fluid was modeled as a viscous liquid with weak compressibility. Boundary conditions,such as a no-slip solid wall, inflow and outflow, and periodic boundaries, were employed to resemble the physical problem. A sensitivity analysis, which has been rarely addressed in previous studies, was conducted on several SPH parameters. Hence, the effects of distinct parameters, such as the kernel choices and the domain dimensions, were investigated with the goal of obtaining highly accurate results. A range of Reynolds numbers(1-500) was simulated, and the results were compared with existing experimental data. It was observed that the domain dimensions and the resolution of SPH particles, in comparison to the obstacle size, affected the obtained drag coefficient significantly. Other parameters, such as the background pressure, influenced the transient condition, but did not influence the steady state at which the drag coefficient was determined.

关键词： Smoothed particle hydrodynamics Drag coefficient Reynolds number Sensitivity analysis Viscous flow

The Shishugou Fauna of the Middle-Late jurassic Transition Period in the junggar Basin of Western China

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Acta Geologica Sinica(English Edition) 2022年第4期96卷 1115-1135页

作者： XU Xing james M.CLARK David A.EBERTH Philip j.CURRIE Centre for Vertebrate Evolutionary Biology Yunnan UniversityKunming 650500China Key Laboratory of Vertebrate Evolution and Human Origins Institute of Vertebrate Paleontology and PaleoanthropologyChinese Academy of SciencesBeijing 100044China Department of Biological Sciences George Washington UniversityWashington DC20052USA Royal Tyrrell Museum of Palaeontology Box 7500DrumhellerAlberta T0J 0Y0Canada Department of Biological Sciences University of Alberta 116 Street and 85 AvenueEdmontonAB T6G 2R3Canada

The Middle-Late jurassic transition period is a critical period for the evolution of terrestrial vertebrates,but the global fossil record from this time is relatively *** Shishugou Fauna of this period has recently produced significant fossil remains of dinosaurs and other vertebrate groups,some representing the earliest known members of several dinosaurian groups and other vertebrate groups and some representing the best-known specimens of their *** discoveries are significant for our understanding of the origin and evolution of several vertebrate *** dating indicates that the fauna is aged approximately 159-164 *** with other similarly-aged terrestrial faunas such as Shaximiao and Yanliao show both taxonomic similarities and differences between these faunas and indicate that the junggar deposits might have preserved the most complete vertebrate fossil record for a Middle-Late jurassic Laurasian terrestrial fauna.

关键词： Middle-Late jurassic Shishugou Fauna Shishugou Formation terrestrial ecosystem Shaximiao Yanliao junggar Basin