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Linking microbial community composition to farming pattern in selenium-enriched region:Potential role of microorganisms on Se geochemistry

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Journal of Environmental Sciences 2022年第2期34卷 269-279页

作者： Yanhong Wang xinyan shi Xianxin Huang Chunlei Huang Helin Wang Hanqin Yin Yixian Shao Ping Li State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesWuhan 430074China Zhejiang Institute of Geological Survey Hangzhou 311203China

Selenium(Se)is an essential micronutrient for *** microbial communities play an important role on Se geochemistry in *** this study,the microbial community composition and functions of 53 soil samples were investigated using high-throughput *** were divided into 3 groups with different farming types based on the measured geochemical parameters and microbial functional *** indicated that putative Se related bacteria Bacillus,Dyella,Paenibacillus,Burkholderia and Brevibacillus were dominant in dryland plantation soils which were characterized with higher available Se and low contents of H_(2)O,total organic carbon(TOC),NH_(4)^(+) and NO_(2)^(-).In contrast,the putative denitrifier Pseudomonas dominated in flooded paddy soils with higher TOC,NO_(3)^(-) and organic Se,whereas genera Rhizobium,Nitrosospira,and Geobacter preferred woodland soils with higher oxidation-reduction potential(ORP),pH,NH_(4)^(+) and *** patterns resulted in distinct geochemical parameters including moisture,pH,ORP,TOC,and contents of soluble Fe,NO_(2)^(-) and NH_(4)^(+),shaping the microbial communities,which in turn affected Se forms in *** study provides a valuable insight into understanding of Se biogeochemistry in soils and prospective strategy for Se-rich agriculture production.

关键词： Selenium biogeochemistry Indigenous microbial community Farming patterns High-throughput sequencing FAPROTAX

Damping Properties of Ethylene-Vinyl Acetate Rubber/Polylactic Acid Blends

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Journal of Materials Science and Chemical Engineering 2016年第3期4卷 15-22页

作者： Xiaozhen He Ming Qu xinyan shi Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber and Plastics Qingdao University of Science and Technology Qingdao China

In this research, ethylene-vinyl acetate rubber (EVM)/polylactic acid (PLA) = 80/20 by weight blend was compounded with silica in a Haake torque rheometer. The effects of hindered phenol (AO-60), super branched polyol, petroleum resin C9, polyvinyl chloride (PVC) and acrylic rubber (ACM) on the damping properties of blends were investigated by dynamic mechanic analyzer (DMA). The results showed that 20 phr super branched polyol significantly increased the damping factor of PLA to widen the effective damping temperature range from 42.1℃to 102.5℃. 15 phr AO-60 and 10 phr petroleum resin C9 both dramatically raised the blend’s damping factor to broaden the effective damping temperature range to 98.0℃ and 102.6℃, respectively. ACM and PVC are compatible with EVM, and both improved the damping properties of EVM/PLA blends.

关键词： DMA EVM/PLA Damping Organic Hybrid

Effects of Fillers on the Damping Property of Ethylene Vinyl-Acetate/Polylactic Acid Blends

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Journal of Materials Science and Chemical Engineering 2016年第2期4卷 89-96页

作者： xinyan shi Lingyan Jia Yan Ma Chengliang Li Key Laboratory of Rubber-Plastics Ministry of Education/Shandong Provincial Key Laboratory of Rubber and Plastics Qingdao University of Science and Technology Qingdao China

New and high performance damping materials from ethylene vinyl-acetate copolymer (VA content over 40%, shorted as EVM) and polylactic acid (PLA) blends were prepared with dicumyl peroxide (DCP) as the curing agent and triallyl isocyanurate (TAIC) as the curing coagent. The effects of silica, mesoporous silica and glass beads on the damping of the EVM/PLA blends were examined using a dynamic mechanical analyzer (DMA). The microstructures of the silica, mesoporous silica and glass beads were observed by transmission electron microscope (TEM). The dispersion of the fillers in the matrix was studied using a Rubber Process Analyzer (RPA). The results showed that silica filled blend had an effective damping temperature range (EDTR, tan δ> 0.3) of 81℃, while the mesoporous silica/silica and glass beads/silica filled blends had EDTR of 86℃ and 85℃, respectively. Mixtures of mesoporous silica and silica as well as glass beads and silica exhibited a more improved dispersion in the blends than silica alone. Blends filled with mesoporous silica and glass beads retained good mechanical properties as well as improved damping performance.

关键词： EVM 700 PLA Damping Silica Mesoporous Silica Glass Beads

A novel selenite-reducing bacterium Bacillus pseudomycoides SA14 isolated from Se-enriched soil and its potential Se biofortification on Brassica chinensis L.

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Journal of Earth Science 2022年

作者： Xianxin Huang Yanhong Wang Helin Wang xinyan shi Chunlei Huang Hanqin Yin Yixian Shao Ping Li State Key Laboratory of Biogeology and Environmental Geology， China University of Geosciences Hubei Key Laboratory of Yangtze Catchment Environmental Aquatic Science， China University of Geosciences Zhejiang Institute of Geological Survey

Microbial participation in biofortification can improve the availability of selenium (Se) in soil and contribute to the enrichment of Se in crops. In this study， a selenite (Se(Ⅳ)) reducing strain was isolated from Se-rich soil， and its Se transformation and bioenhancement ability were studied. The strain was identified as Bacillus pseudomycoides and could reduce more than 93.48% of 1.0 mmol/L Se(Ⅳ) in 54 h. The results of scanning electron microscope (SEM) and energy dispersive X-ray spectrometry (EDS) showed that Se(Ⅳ) was reduced to Se(0)， and Se nanoparticles (SeNPs) were eventually formed. In pot experiments， B. pseudomycoides SA14 could promote the bioavailable Se in soils and the concentration of Se in Brassica chinensis L.. The concentrations of water-soluble Se， ion exchange Se and carbonate-binding Se in soil were increased by 23.13%， 22.05% and 30.89%， respectively. The Se concentration of Brassica chinensis L. in pot experiments was increased by 145.05%. The relative abundance of Bacillus in soil increased from 0.97% to 2.08% in the pot experiments. As far as we know， this is the first report of Se reduction by B. pseudomycoides. This study might provide a prospective strategy for microbial fortification of Se in crops.

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不同等级散打运动员肘、膝关节肌群等速测试肌力特征研究

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天津体育学院学报 2012年第2期27卷 168-172页

作者：石新燕陕西中医学院体育部陕西咸阳712046

结合训练实践,运用ISOMED2000等速测试仪对我国男子散打主力队员膝、肘关节屈伸肌群肌力特征进行测试与分析。结论:不同等级散打运动员肘关节屈伸肌群等速向心、离心收缩、膝关节伸肌群等速离心收缩相对峰力矩值在60°/s、180°/s时具... 详细信息

结合训练实践,运用ISOMED2000等速测试仪对我国男子散打主力队员膝、肘关节屈伸肌群肌力特征进行测试与分析。结论:不同等级散打运动员肘关节屈伸肌群等速向心、离心收缩、膝关节伸肌群等速离心收缩相对峰力矩值在60°/s、180°/s时具有显著性差异(P<0.05);膝关节屈伸肌群等速向心收缩、屈肌群离心收缩相对峰力矩值在各角速度下具有显著性差异(P<0.05);不同等级散打运动员肘、膝关节屈伸肌群等速向心收缩在300°/s、离心收缩在240°/s时达到力矩梯度最大值,且差异显著。说明基础力量、中快速力量及快速动作爆发力能较好地反映专项运动水平,相对峰力矩、力矩梯度数值越大,专项水平越高。

关键词：散打肘关节膝关节等速向心收缩等速离心收缩力矩梯度

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EVM基共混物的阻尼性能

高分子材料科学与工程 2011年第5期27卷 89-91,95页

作者：史新妍毕薇娜青岛科技大学橡塑材料与工程教育部重点实验室山东青岛266042 农业部热带作物产品加工重点开放实验室广东湛江524001

选用双叔丁基过氧化异丙基苯(BIPB)作为硫化剂,采用动态粘弹谱仪(DMA)对乙烯-醋酸乙烯酯橡胶(EVM)/乙丙胶(EPDM)和EVM/丁腈胶(NBR)两种共混体系的阻尼性能进行了研究。考察了聚氯乙烯(PVC)、N-环己基-2-苯并噻唑次磺酰胺(CZ)以及过氧化... 详细信息

选用双叔丁基过氧化异丙基苯(BIPB)作为硫化剂,采用动态粘弹谱仪(DMA)对乙烯-醋酸乙烯酯橡胶(EVM)/乙丙胶(EPDM)和EVM/丁腈胶(NBR)两种共混体系的阻尼性能进行了研究。考察了聚氯乙烯(PVC)、N-环己基-2-苯并噻唑次磺酰胺(CZ)以及过氧化二异丙苯(DCP)对EVM基共混物阻尼性能的影响。实验结果表明,PVC在共混物EVM/EPDM中,与EVM700完全相容,可以显著改善EVM在高温区的阻尼性能。PVC与EVM/NBR共混体系发生部分相容,能显著拓宽有效阻尼温域,高达62.4℃;与BIPB相比,DCP使EVM/NBR的阻尼因子峰得到显著拓宽,有效阻尼温域高达64.9℃。少量的CZ对EVM/NBR=80/20共混物阻尼因子有显著增大和拓宽作用。

关键词：乙烯-醋酸乙烯酯橡胶聚氯乙烯共混阻尼乙丙胶丁腈胶

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我国蔬菜种子国际贸易格局与竞争力评价研究

中国瓜菜 2022年第4期35卷 112-116页

作者：石鑫岩河套学院经济管理系内蒙古巴彦淖尔015000

近年来我国蔬菜种子国际贸易日益繁荣。从贸易规模、贸易对象、贸易价格等方面对当前我国蔬菜种子国际贸易格局进行了深入分析,并选取国际市场占有率、贸易竞争力指数、出口价格指数等指标,对我国蔬菜种子国际竞争力水平进行了评价。研... 详细信息

近年来我国蔬菜种子国际贸易日益繁荣。从贸易规模、贸易对象、贸易价格等方面对当前我国蔬菜种子国际贸易格局进行了深入分析,并选取国际市场占有率、贸易竞争力指数、出口价格指数等指标,对我国蔬菜种子国际竞争力水平进行了评价。研究结果表明,2017—2020年期间,我国蔬菜种子国际贸易规模不断扩大,但贸易对象相对比较集中,进出口贸易价格之间也存在较大差距。与此同时,从综合评价结果来看,目前我国蔬菜种子的国际竞争力相对较弱,且有逐年下降的发展趋势。最后,从加快品种创新步伐、加大种子企业培育、加强信息服务建设等方面提出了有效提升我国蔬菜种子国际竞争力水平的政策建议。

关键词：蔬菜种子贸易格局国际竞争力政策建议

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学术博客链接结构及其交流特性分析

图书情报知识 2009年第5期26卷 79-83,89页

作者：史新艳肖仙桃中国科学院国家科学图书馆兰州分馆兰州730000

本文给出了学术博客的定义和特征,分析了学术博客这种网络交流形式中存在的链接行为,从链接在页面中的具体位置所体现出的链接动机进行分类,着重对首页、博客文章页面的链接位置从其页面形式和源代码中查看,做好博客链接分析工作,并根... 详细信息

本文给出了学术博客的定义和特征,分析了学术博客这种网络交流形式中存在的链接行为,从链接在页面中的具体位置所体现出的链接动机进行分类,着重对首页、博客文章页面的链接位置从其页面形式和源代码中查看,做好博客链接分析工作,并根据本文给出的博客交流结构讨论了学术博客在学术交流中的特性,为深入研究学术博客交流传播特征作好准备。

关键词：学术博客链接位置链接动机链接分类

退火对聚乳酸/丙烯酸酯橡胶共混物结晶行为的影响

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高分子材料科学与工程 2018年第10期34卷 79-83,90页

作者：常宪增李诚亮史新妍青岛科技大学橡塑材料与工程教育部重点实验室山东青岛266042

以丙烯酸酯橡胶(ACM)和聚乳酸(PLA)为基体制备共混体系,研究了不同配比的共混物在结晶和非晶状态下力学性能的差异,以及不同的PLA/ACM配比、退火温度和退火时间对共混物结晶行为的影响。结果表明,在淬火和退火条件下,ACM的加入都会使PLA... 详细信息

以丙烯酸酯橡胶(ACM)和聚乳酸(PLA)为基体制备共混体系,研究了不同配比的共混物在结晶和非晶状态下力学性能的差异,以及不同的PLA/ACM配比、退火温度和退火时间对共混物结晶行为的影响。结果表明,在淬火和退火条件下,ACM的加入都会使PLA/ACM共混体系的拉伸强度下降,断裂伸长率上升,但退火条件下,共混物的结晶减弱了ACM对共混物力学性能的影响。ACM含量低时促进共混物中PLA的结晶。纯PLA在退火温度为110℃、退火时间为15 min时,形成稳定的α晶型,ACM的加入,使PLA产生α'晶型。随着退火时间的延长和退火温度的升高,共混物的结晶度提高,且升高退火温度对结晶度的影响更明显。

关键词：丙烯酸酯橡胶聚乳酸力学性能退火结晶行为