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Microplastics in Freshwater Environments and Implications for Aquatic Ecosystems: A Mini Review and Future Directions in Ghana
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作者 Joseph Acquah haicheng liu +2 位作者 Shuangling Hao Yue Ling Jie Ji 《Journal of Geoscience and Environment Protection》 2021年第3期58-74,共17页
Microplastics have a constant effect on aquatic life and are constantly being researched, they have been gradually observed and analysed in marine and freshwater ecosystems, and possible effects in freshwater ecosyste... Microplastics have a constant effect on aquatic life and are constantly being researched, they have been gradually observed and analysed in marine and freshwater ecosystems, and possible effects in freshwater ecosystems are rising in importance. A literature review has been completed to outline the present state of awareness of microplastics in freshwater ecosystems in Ghana;in particular, the environmental fate, sources, effects in aquatic life and implications on their environments. Although we found that there was a dramatic increase in research and publications on these subjects, relatively few studies had examined the sources, fate and impacts of microplastics in the water bodies of Ghana and there was insufficient data on the extent of microplastics in freshwaters in Ghana. Studies in which Ghanaian waterbodies had quantified microplastics were considered of the greatest importance. We further assess current depth of knowledge of microplastics in aquatic ecosystems in which Ghanaian ecosystem-specific information was not readily available. Although this study may not be a comprehensive overview of the findings, it is assumed that this is an objective representation of the existing state of awareness about microplastics in the aquatic environment in Ghana. 展开更多
关键词 Microplastics (MPs) FRESHWATER Aquatic Ecosystem Ghana
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冰灯玉露离体诱变技术 被引量:5
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作者 周海成 刘艳军 +3 位作者 黄俊轩 杨静慧 李建科 武春霞 《天津农业科学》 CAS 2017年第7期25-28,共4页
为了获得冰灯玉露新品种,采用冰灯玉露松散型胚性愈伤组织为诱变试材,采用浸泡法和在培养基中加入诱变剂的方法进行离体诱变。通过采用不同浓度EMS和不同处理时间,找到愈伤组织半致死剂量的EMS使用浓度和时间,并在此条件下对冰灯玉露松... 为了获得冰灯玉露新品种,采用冰灯玉露松散型胚性愈伤组织为诱变试材,采用浸泡法和在培养基中加入诱变剂的方法进行离体诱变。通过采用不同浓度EMS和不同处理时间,找到愈伤组织半致死剂量的EMS使用浓度和时间,并在此条件下对冰灯玉露松散型胚性愈伤组织进行离体诱变,获得形态变化的突变体。结果显示,采用在培养基中加入0.1%EMS处理4 d可以获得理想的半致死效果。以此条件处理冰灯玉露愈伤组织,通过再生培养可以获得1.5%的形态变异的个体,这些个体的遗传变异情况有待进一步检测。 展开更多
关键词 冰灯玉露 半致死剂量 诱变剂 愈伤组织
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叠合楼板极限承载力研究 被引量:7
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作者 刘海成 郑旭 刘强 《沈阳建筑大学学报(自然科学版)》 CAS 北大核心 2016年第5期788-796,共9页
目的研究装配式混凝土结构中叠合楼板在竖向荷栽作用下的极限承栽力,为叠合楼板配筋设计提供参考.方法基于ABAQUS有限元分析软件对底部2块与3块预制板拼接,工程中常用预制厚度与现浇层厚度,以及长宽比1.0~1.5范围的30组叠合楼板... 目的研究装配式混凝土结构中叠合楼板在竖向荷栽作用下的极限承栽力,为叠合楼板配筋设计提供参考.方法基于ABAQUS有限元分析软件对底部2块与3块预制板拼接,工程中常用预制厚度与现浇层厚度,以及长宽比1.0~1.5范围的30组叠合楼板在竖向荷载作用下进行数值计算分析,得到沿拼缝方向按单向板配筋且垂直拼缝方向固定构造配筋、竖向荷载作用下四边简支的叠合楼板极限承载力;并计算在楼板极限承载力不变的前提下,按照双向板进行计算,得出沿拼缝方向受力筋面积可减少的比率.结果沿拼缝方向按单向板配筋、垂直拼缝方向固定构造配筋的叠合楼板,如果拼缝方向作为长方向,当长宽比为1:1.5时,其实际极限承载力比按照单向板计算值可提高17%;长宽比为1:1时,承载力可提高39%,长宽比为1.5:1时,承载力可提高98%.极限承载力相同时,按照双向板计算,当长宽比为1:1.5时,预制板中沿拼缝方向受力筋可减少17%,可按照平行拼缝方向的单向板计算;当长宽比为l:1.2时,预制板中沿拼缝方向受力筋可减少30%,;当长宽比为l:1时,预制板中沿拼缝方向受力筋可减少40%;当长宽比为1.2:l时,预制板中沿拼缝方向配筋可减少60%;当长宽比为1.5:1时,预制板中沿拼缝方向受力筋计算上可不配,叠合板相当于垂直拼缝方向受力为主的单向板.结论同尺寸、不同预制厚度与现浇层厚度的叠合楼板,现浇层厚度与预制板比值越大,承载力越大;底部2块预制板的叠合楼板与相同配筋的底部3块预制板的叠合楼板相比,承载力较低.叠合楼板应避免拼缝与楼板中线重舍的布置,且当长宽比大于1.5:1时,建议沿短边方向布置预制板. 展开更多
关键词 装配式混凝土结构 叠合楼板 极限承载力 长宽比
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