Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbon...Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM,the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM,and the strengthening mechanism was analyzed.The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate.It is suggested that the replacement rate of recycled powder should not exceed 20%.The strength index and activity index of carbonated recycled powder mortar were improved,in which the flexural strength was increased by 27.85%and compressive strength was increased by 20%at the maximum.Recycled powder can be quickly and completely carbonated,and the improvement effect of CH pre-soaking carbonation was the best.The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder.Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect,alkaline polycondensation effect and carbonation enhancement effect.展开更多
目的分析医院健康科普信息发布现状以及健康科普传播效果,并探讨其影响因素。方法选择上海交通大学医学院所有12家附属医院进行研究,获取2022年10月1日—2023年9月30日其官方微信公众号发布的健康科普推文,使用微信传播指数(WeChat Comm...目的分析医院健康科普信息发布现状以及健康科普传播效果,并探讨其影响因素。方法选择上海交通大学医学院所有12家附属医院进行研究,获取2022年10月1日—2023年9月30日其官方微信公众号发布的健康科普推文,使用微信传播指数(WeChat Communication Index,WCI)一级和二级指标对微信公众号健康科普传播的效果进行综合分析,并探讨其影响因素。结果12家医院共发布推文2791篇;其中,健康科普文章1470篇,占比52.67%,平均阅读量为8881.44次/篇。各医院的健康科普推文数量和传播影响力存在差异,综合医院的传播力整体高于专科医院。Kruskal-Wallis检验结果显示,各家医院健康科普推文的阅读数、点赞数、在看数和WCI指数间差异均有统计学意义(P均<0.01)。WCI指数最高的12篇文章阅读数均达到了10万以上。推文的影响力受多个因素共同影响,如标题句式、发布位置、主题内容等。其中,标题以否定反问句的句式、位于头条位置能够显著提高推文的阅读数(P<0.05)。高影响力推文主题主要体现在养生保健、药品安全、营养膳食等领域(P<0.05)。结论医院发布的健康科普推文整体传播力较高,但差异较大。医院应从“质”“量”并重、塑造品牌形象、关注健康热点、创新科普形式等方面入手,重视健康科普推文的标题、位置、内容,切实提高健康科普信息的传播效果。展开更多
基金Funded by Joint Funds of the National Natural Science Foundation of China(No.U1904188)Jiangxi Provincial Department of Education Science and Technology Project(Nos.GJJ171079,GJJ181023 and GJJ181022)。
文摘Carbonated recycled powder as cementitious auxiliary material can reduce carbon emissions and realize high-quality recycling of recycled concrete.In this paper,microscopic property of recycled powder with three carbonation methods was tested through XRD and SEM,the mechanical property and microstructure of recycled powder mortar with three replacement rates were studied by ISO method and SEM,and the strengthening mechanism was analyzed.The results showed that the mechanical property of recycled powder mortar decreased with the increasing of replacement rate.It is suggested that the replacement rate of recycled powder should not exceed 20%.The strength index and activity index of carbonated recycled powder mortar were improved,in which the flexural strength was increased by 27.85%and compressive strength was increased by 20%at the maximum.Recycled powder can be quickly and completely carbonated,and the improvement effect of CH pre-soaking carbonation was the best.The activity index of carbonated recycled powder can meet the requirements of Grade II technical standard for recycled powder.Microscopic results revealed the activation mechanism of carbonated recycled powder such as surplus calcium source effect,alkaline polycondensation effect and carbonation enhancement effect.
文摘目的分析医院健康科普信息发布现状以及健康科普传播效果,并探讨其影响因素。方法选择上海交通大学医学院所有12家附属医院进行研究,获取2022年10月1日—2023年9月30日其官方微信公众号发布的健康科普推文,使用微信传播指数(WeChat Communication Index,WCI)一级和二级指标对微信公众号健康科普传播的效果进行综合分析,并探讨其影响因素。结果12家医院共发布推文2791篇;其中,健康科普文章1470篇,占比52.67%,平均阅读量为8881.44次/篇。各医院的健康科普推文数量和传播影响力存在差异,综合医院的传播力整体高于专科医院。Kruskal-Wallis检验结果显示,各家医院健康科普推文的阅读数、点赞数、在看数和WCI指数间差异均有统计学意义(P均<0.01)。WCI指数最高的12篇文章阅读数均达到了10万以上。推文的影响力受多个因素共同影响,如标题句式、发布位置、主题内容等。其中,标题以否定反问句的句式、位于头条位置能够显著提高推文的阅读数(P<0.05)。高影响力推文主题主要体现在养生保健、药品安全、营养膳食等领域(P<0.05)。结论医院发布的健康科普推文整体传播力较高,但差异较大。医院应从“质”“量”并重、塑造品牌形象、关注健康热点、创新科普形式等方面入手,重视健康科普推文的标题、位置、内容,切实提高健康科普信息的传播效果。