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Simultaneously enhancing the strength and ductility of as-extruded AlN/AZ91 composites via nano-precipitation and pyramidal slip

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Journal of Materials Science & Technology 2024年第5期172卷 240-254页

作者： Bin Zhang Yunxia Sun Tuo liang yunzhen li Tian li Jingchao Wang Ruiru Cai Changlin Yang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Age hardening is often used to optimize the mechanical properties of as-deformed Mg-based materials in industry,whereas the improvement of strength is usually accompanied by the significant loss of ductility,which hinders the application of Mg-based materials in structural *** the present work,high strength-ductility synergy(the yield strength of 263±9 MPa,ultimate tensile strength of 398±7 MPa and elongation to fracture of 34%±1%)was realized in as-extruded AlN/AZ91 composites after optimiz-ing aging *** characterization shows that AlN particles induced a large number of geometrically necessary dislocations around the AlN/Mg interface during extrusion,which decreased the nucleation barrier and provided more heterogeneous nucleation sites forγ-Mg 17 Al 12 continuous ***,95%of residual dislocations in as-extruded AlN/AZ91 composites were annihilated dur-ing peak-aging,suppressing the growth and coarsening of continuous ***,high density of nano-sizedγ-Mg 17 Al 12 continuous precipitates was produced in as-extruded AlN/AZ91 composites af-ter *** tension,gliding dislocations bypassed sphericalγ-Mg 17 Al 12 nano-precipitates by Orowan looping rather than cutting mechanism,which induced a strong block on dislocation *** high yield strength was mainly attributed to the high density of non-shearableγ-Mg 17 Al 12 nano-precipitates with spherical morphology,which was different from other Mg-Al-based *** results of texture evolution and slip trace analysis demonstrated that the suppression of extension twinning and less basal slip was due to the enhanced activity of pyramidalc+aslip in as-extruded AlN/AZ91 com-posites after peak-aging during the room temperature tension,meanwhile,the dislocation density of as-extruded AlN/AZ91 composites was significantly decreased during peak-aging,then higher elongation to fracture was achieved.

关键词： Magnesium matrix composites Mechanical properties Precipitation Deformation mechanisms Non-basal slip

Investigating the spectral characteristic and humification degree of dissolved organic matter in saline-alkali soil using spectroscopic techniques

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Frontiers of Earth Science 2017年第1期11卷 76-84页

作者： Qiang li Xujing GUO Lu CHEN yunzhen li Donghai YUAN Benlin DAI Sisi WANG Department of land Management School of Urban Economics and Public Administration Capital University of Economics and Business Beijing 100070 China College of Resources and Environment Chengdu University of Information Technology Chengdu 610225 China Key Laboratory of Development and Application of Rural Renewable Energy Ministry of Agriculture Biogas institute of Ministry of Agriculture Chengdu 610041 China Sichuan. Academy of Environmental Science Chengdu 610041 China Key Laboratory of Urban Stormwater System and Water Environment Ministry of Education Beijing University of Civil Engineering and Architecture Beijing 100044 China Jiangsu Key Laboratory for Biomass-based Energy and Enzyme Technology Huaiyin Normal University Huaian 223300 China

Soil samples were collected from the areas surrounding Wuliangsuhai Lake in China. Dissolved organic matter （DOM） was extracted from the samples and characterized by fluorescence and UV-Vis spectra. Spectral properties and humification degree of DOM were studied. The results indicated that both humic- and protein- like fluorophores were present in the DOM spectra, and the former was the dominant component. The analysis of humification （HIX） and r （A, C） indices revealed that the maximum humification degree in three agricultural soils （AAF, ASC, and ASW） was presented in the second soil layer （20-40 cm）. However, the humification degree of the two Halophytes soils （SSE and GKF） decreased with increasing depth. One index, I344/270, showed that humification degree increased gradually with an increasing proportion of humic-like acid. There was a significant positive correlation between humification degree （HIX） and aromaticity （SUVA254）, indicating that a higher aromaticity corresponded to a higher humification degree. Land use was an important factor responsible for the major difference of cation exchange capacity （CEC） in different soils, which led to a higher CEC value in the second soil layer for the three agricultural soils. CEC values and humification degree had the same trend for all five soils. The correlation analysis showed that there was a significant positive correlation between HIX and CEC,and a negative correlation between the r （A, C） index and CEC, indicating that humification degree increases gradually with increasing CEC values.

关键词： dissolved organic matter fluorescence spectroscopy humification degree cation exchange capacity

Epigenetic control on transcription of vernalization genes and whole-genome gene expression profile induced by vernalization in common wheat

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Plant Diversity 2024年第3期46卷 386-394页

作者： yunzhen li liujie Jin Xinyu liu Chao He Siteng Bi Sulaiman Saeed Wenhao Yan National Key Laboratory of Crop Genetic Improvement Hubei Hongshan LaboratoryHuazhong Agricultural UniversityWuhan 430070China

Vernalization is necessary for winter wheat to ***,it is unclear whether vernalization is also required for spring wheat,which is frequently sown in fall,and what molecular mechanisms underlie the vernalization response in wheat *** this study,we examined the molecular mechanisms that regulate vernalization response in winter and spring wheat *** this purpose,we determined how major vernalization genes(VRN1,VRN2,and VRN3)respond to vernalization in these varieties and whether modifications to histones play a role in changes in gene *** also identified genes that are differentially regulated in response to vernalization in winter and spring wheat *** found that in winter wheat,but not in spring wheat,VRN1 expression decreases when returned to warm temperature following *** finding may be associated with differences between spring and winter wheat in the levels of tri-methylation of lysine 27 on histone H3(H3K27me3)and tri-methylation of lysine 4 on histone H3(H3K4me3)at the VRN1 *** of winter wheat transcriptomes before and after vernalization revealed that vernalization influences the expression of several genes,including those involved in leucine catabolism,cysteine biosynthesis,and flavonoid *** findings provide new candidates for further study on the mechanism of vernalization regulation in wheat.

关键词： Wheat Vernalization VRN1 Histone modification Regulate network

考虑第三偏应力不变量的岩石局部化变形预测模型

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岩石力学与工程学报 2010年第7期29卷 1450-1456页

作者：李云祯黄涛戴本林蔡臣西南交通大学环境科学与工程学院四川成都610031 美国西北大学土木与环境工程系埃文斯顿il60208 河海大学环境科学与工程学院江苏南京210098

现有岩石局部化变形带发生条件与带角预测模型均只考虑2个应力不变量,预测结果与实验观测结果关联度不好,最近的研究表明第三应力不变量在局部化变形中起重要的作用。在Rudnicki与Rice单屈服面和Issen双屈服面模型的基础上,通过相似角... 详细信息

现有岩石局部化变形带发生条件与带角预测模型均只考虑2个应力不变量,预测结果与实验观测结果关联度不好,最近的研究表明第三应力不变量在局部化变形中起重要的作用。在Rudnicki与Rice单屈服面和Issen双屈服面模型的基础上,通过相似角表征第三偏应力不变量,得到第三偏应力不变量相关性模型判断岩石局部化变形发生条件和预测变形带角,利用Mogi的Dunham白云岩轴对称拉伸和压缩状态以及Haimson的Westly花岗岩轴对称拉伸实验的变形带角属性作为边界条件,计算得到模型中的弹塑性参数,最后预测得到其他一般应力状态的变形带角,相较于二应力不变量模型,提高局部化变形带角的预测精度。

关键词：岩石力学局部化变形 RR理论 Issen双屈服面模型临界硬化模量变形带角第三应力不变量相关性模型

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新疆干旱时空动态及其对气候变化的响应

自然资源遥感 2022年第4期34卷 216-224页

作者：程军李云祯邹渝渭南师范学院环境与生命科学学院渭南714099 四川大学水利水电学院成都610065 四川省生态环境科学研究院成都610041

为实现对新疆地区旱情的动态连续监测,基于温度植被干旱指数(temperature vegetation dryness index,TVDI),辅以Sen斜率法、重标极差法及偏相关分析法探究了新疆2001—2020年TVDI时空动态、变化趋势、未来持续状态及季节性降水、气温对T... 详细信息

为实现对新疆地区旱情的动态连续监测,基于温度植被干旱指数(temperature vegetation dryness index,TVDI),辅以Sen斜率法、重标极差法及偏相关分析法探究了新疆2001—2020年TVDI时空动态、变化趋势、未来持续状态及季节性降水、气温对TVDI的影响。结果表明:①TVDI最小值出现在天山山脉以北及昆仑山脉地区,TVDI值在0.57以下,属轻旱等级,塔里木盆地和准噶尔盆地TVDI在0.86以上,属特旱等级;②春季TVDI呈减小趋势,减小速率为0.0013/a,夏季TVDI增加速率为0.0014/a,秋季TVDI增加速率最大(增加速率为0.0020/a),冬季TVDI增加速率最小(增加速率为0.0008/a);③春、冬季未来一段时间内大部分区域TVDI将呈增加趋势,夏、秋季TVDI将在未来一段时间内大部分像元呈减小趋势;④春、冬季TVDI与降水以负相关为主,夏、秋季TVDI与降水以正相关为主,春季TVDI与气温以正相关为主,夏季TVDI与气温的相关性从西向东递减,相关性从负相关逐渐变成正相关,秋、冬季TVDI与气温以负相关为主。

关键词： TVDI 气温降水新疆

青光双刺甲(Bioramix aenescens)(鞘翅目:拟步甲科:刺甲族)的再描述

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云南农业大学学报（自然科学版） 2015年第1期30卷 133-136页

作者：刘丽李云臻石爱民西华师范大学生命科学学院四川南充637002

刺甲是鞘翅目(Coleoptera)拟步甲科(Tenebrionidae)刺甲族(Platyscelidini)昆虫的统称,是荒漠半荒漠地区的优势类群,对维持该地区的生态系统平衡具有重要意义。青光双刺甲(Bioramix aenescens)是我国较为罕见的一类昆虫,笔者于2012年在... 详细信息

刺甲是鞘翅目(Coleoptera)拟步甲科(Tenebrionidae)刺甲族(Platyscelidini)昆虫的统称,是荒漠半荒漠地区的优势类群,对维持该地区的生态系统平衡具有重要意义。青光双刺甲(Bioramix aenescens)是我国较为罕见的一类昆虫,笔者于2012年在西藏措勤地区采集到该种。由于原始描述过于简单,且缺少分类特征和整体照片,对植物保护工作及相关研究造成一定困难。本文对其进行了详细描述,并附有特征图和整体照片。检视标本保存于西华师范大学标本馆和俄罗斯楚瓦什国立师范大学标本馆。

关键词：拟步甲科刺甲族青光双刺甲再描述

黄颡鱼寄生东肌吸虫属(复殖吸虫亚纲:东肌吸虫科)3种复殖吸虫的分类学研究

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四川动物 2020年第6期39卷 616-629页

作者：李寄仟李云臻范丽仙云南师范大学生命科学学院昆明650500 生物能源持续开发利用教育部工程研究中心昆明650500

本研究报道采自云南澜沧江水系黄颡鱼Pelteobagrus fulvidraco(鲿科Bagridae)东肌吸虫属Orientocreadium Tubangui,1931复殖吸虫3种,包括黄颡东肌吸虫新种*** ***.以及*** Yamaguti,1934(中国新记录种)和印度东肌吸虫*** Pande,1934。黄颡东肌吸虫新种区别于本属其他物种的形态特征包括:体表无棘,口吸盘略小于腹吸盘,虫体末端较圆钝,卵黄腺从卵巢前缘水平分布至后睾丸之后,子宫末段内壁具棘等。基于28S rDNA部分序列的系统发育分析支持东肌吸虫科Orientocreadiidae为单系类群,与Leptophallidae构成姊妹群。黄颡东肌吸虫新种与印度东肌吸虫亲缘关系较近。

关键词：复殖吸虫黄颡鱼东肌吸虫属新种 28S rDNA

火山岛弧带对盆地沉积体系形成与分布的影响:以缅甸陆上钦敦-睡宝盆地某区块为例

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地质科技情报 2014年第3期33卷 36-43页

作者：李运振赵汝敏赵厚祥中海油研究总院北京100027

由于大洋板块向大陆板块的不断俯冲,在钦敦-睡宝盆地的中部形成南北向断续分布的火山岛弧。自白垩纪至中新世,岛弧带的火山喷发整体较为连续,并经历了4个演化时期。由于岛弧带相距周围的区域物源较远,沉积物供给相对不足,火山喷发强烈... 详细信息

由于大洋板块向大陆板块的不断俯冲,在钦敦-睡宝盆地的中部形成南北向断续分布的火山岛弧。自白垩纪至中新世,岛弧带的火山喷发整体较为连续,并经历了4个演化时期。由于岛弧带相距周围的区域物源较远,沉积物供给相对不足,火山喷发强烈时形成的火山碎屑物会成为其附近区域的主要物源。岛弧带的火山活动不仅改变沉积体系的物质组成,还对沉积体系的展布起到阻挡作用,并在其周围形成新的沉积体系。宽缓的海岸平原-滨浅海沉积背景使盆地具备形成沼泽的先天条件,在偏离岛弧带不受火山活动影响的地区能够发育大范围的煤系地层,而在受火山活动影响的岛弧带内只发育小范围的煤系地层。由于持续的火山活动对优质储层的形成不利,应尽量避免在火山影响范围较大的地区寻找有利储层。

关键词：火山岛弧带火山活动沉积体系物源煤系地层

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铁尾矿制备聚合硫酸铁实验及造纸污水处理效果初步评价

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无机盐工业 2021年第8期53卷 96-100页

作者：纪丁愈李云祯邹渝四川水利职业技术学院四川崇州611231 四川省生态环境科学研究院

为了分析外界因素对制备聚合硫酸铁的影响,开展了不同条件下的酸浸还原实验和聚合合成实验,优化了实验条件,进而分析不同pH、不同絮凝剂用量以及不同沉降时间作用下,聚合硫酸铁对污染水的处理效果。结果表明:酸浸实验中尾矿全铁浸出实... 详细信息

为了分析外界因素对制备聚合硫酸铁的影响,开展了不同条件下的酸浸还原实验和聚合合成实验,优化了实验条件,进而分析不同pH、不同絮凝剂用量以及不同沉降时间作用下,聚合硫酸铁对污染水的处理效果。结果表明:酸浸实验中尾矿全铁浸出实验的最佳温度为100℃,最佳搅拌时间为2 h,最佳搅拌速度为300 r/min;还原试验中硫酸亚铁还原率的最佳还原温度为60℃,最佳还原时间为1.5 h,还原铁粉的过量系数为1.10%。聚合合成实验中最佳聚合温度为35℃,最佳聚合时间为0.4 h;此条件下,n(双氧水)∶n(Fe^(2+))∶n(磷酸钠)为0.08∶1∶0.07时,聚合效果最优。在pH为7中性环境中,聚合硫酸铁的质量浓度为2.0 g/mL,沉降时间为0.3 h时,污水的余浊值最小,对于污水的处理效果最好。

关键词：铁尾矿酸浸还原实验絮凝剂聚合硫酸铁