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高性能混凝土用水量的计算及低用水量的技术途径
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作者 刘华伟 李新光 徐会娟 《科技信息》 2012年第29期333-333,389,共2页
本文阐述了高性能混凝土用水量的取值原则,对高性能混凝土用水量的计算及实现高性能混凝土低用水量的技术途径进行了探究。
关键词 高性能混凝土 用水量 外加剂 低用水量技术途径
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混凝土质量控制——用水量的过程控制
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作者 王明荣 《商品混凝土》 2015年第12期65-66,共2页
本文着重针对质量控制关键之一用水量的控制做出总结,再次提出其重要性以提醒新进从业人员以及同行对质量控制的关注。
关键词 混凝土 过程控制 低用水量 快速确定
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低用水大掺量粉煤灰高性能砼的耐久性研究 被引量:8
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作者 冯庆革 杨义 +2 位作者 杨绿峰 陈正 朱惠英 《武汉理工大学学报》 CAS CSCD 北大核心 2009年第4期148-150,154,共4页
采用ASTM1202—97、GBJ82—85和压汞法研究了低用水量、低水胶比下,大掺量粉煤灰高性能混凝土的抗氯离子渗透性和抗碳化性能,结果表明,掺加粉煤灰的混凝土抗氯离子渗透性得到明显改善,适量的粉煤灰对水泥替代量对混凝土的抗碳化性能影... 采用ASTM1202—97、GBJ82—85和压汞法研究了低用水量、低水胶比下,大掺量粉煤灰高性能混凝土的抗氯离子渗透性和抗碳化性能,结果表明,掺加粉煤灰的混凝土抗氯离子渗透性得到明显改善,适量的粉煤灰对水泥替代量对混凝土的抗碳化性能影响不大,粉煤灰掺量为30%混凝土的抗碳化性能最好,当混凝土中粉煤灰对水泥的取代量达到70%时,混凝土的抗碳化能力急剧下降;混凝土中Ca(OH)2的明显减少,生成更多的C-S-H凝胶和含铝(铁)水化物以及孔隙细化是混凝土抗氯离子渗透性和抗碳化性能得到改善的根本原因。 展开更多
关键词 粉煤灰 混凝土 低用水量 氯离子渗透性 抗碳化性能
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粉煤灰掺量对高性能混凝土性能的影响
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作者 刘峰 《科技与企业》 2012年第12期316-317,共2页
本文结青荣城际铁路高性能混凝土的配合比设计,研究了粉煤灰掺量对高性能混凝土的影响,结果表明,在低用水量、低水胶比下,粉煤灰掺量为30%-70%时,混凝土的后期强度增长速率快且增长率显著提高;掺粉煤灰混凝土中Ca(OH)2含量跟水化龄期和... 本文结青荣城际铁路高性能混凝土的配合比设计,研究了粉煤灰掺量对高性能混凝土的影响,结果表明,在低用水量、低水胶比下,粉煤灰掺量为30%-70%时,混凝土的后期强度增长速率快且增长率显著提高;掺粉煤灰混凝土中Ca(OH)2含量跟水化龄期和掺量有很大关系,在28d时,粉煤灰已经能够很好的与水泥水化产生的Ca(OH)2发生反应;混凝土中Ca(OH)2的明显减少和内部结构的改善是低用水量大掺量粉煤灰混凝土后期强度增长率显著提高的主要原因。 展开更多
关键词 粉煤灰 掺量 高性能 低用水量 强度
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Development of a concentration method for detection of tobacco mosaic virus in irrigation water 被引量:1
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作者 Wei Chen Wenting Liu +3 位作者 Honghong Jiao Huawei Zhang Julong Cheng Yunfeng Wu 《Virologica Sinica》 SCIE CAS CSCD 2014年第3期155-161,共7页
Tobacco mosaic virus(TMV) causes significant yield loss in susceptible crops irrigated with contaminated water. However, detection of TMV in water is difficult owing to extremely low concentrations of the virus. Here,... Tobacco mosaic virus(TMV) causes significant yield loss in susceptible crops irrigated with contaminated water. However, detection of TMV in water is difficult owing to extremely low concentrations of the virus. Here, we developed a simple method for the detection and quantification of TMV in irrigation water. TMV was reliably detected at concentrations as low as 10 viral copies/μL with real-time PCR. The sensitivity of detection was further improved using polyethylene glycol 6000(PEG6000, MW 6000) to concentrate TMV from water samples. Among the 28 samples from Shaanxi Province examined with our method, 17 were tested positive after virus concentration. Infectivity of TMV in the original water sample as well as after concentration was confirmed using PCR. The limiting concentration of TMV in water to re-infect plants was determined as 102 viral copies/mL. The method developed in this study offers a novel approach to detect TMV in irrigation water, and may provide an effective tool to control crop infection. 展开更多
关键词 tobacco mosaic virus polyethylene glycol real-time PCR irrigation water
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Impact of Mechanization on Lowland Rice Production in Nigeria
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作者 Faleye Tope David James +2 位作者 Olulani Temitope Dada-Joel Yinka Segun Ademiluyi Toshiyuki Wakatsuki 《Journal of Agricultural Science and Technology(B)》 2012年第1期114-120,共7页
The study examined the impact of using power tiller as a means of mechanizing lowland rice production in Nigeria. The study was carried out in Bida area, Niger State, where the sawah rice production was disseminated b... The study examined the impact of using power tiller as a means of mechanizing lowland rice production in Nigeria. The study was carried out in Bida area, Niger State, where the sawah rice production was disseminated by Watershed Initiative in Nigeria (WIN). And in Ajase Ipo of Kwara State, some of the parameters assessed during the study included average speed of operation, average wheel slip/travel reduction, average draught of implement, and fuel consumption. The cost of operation and yield over five years of usage at Niger State and two years in Kwara State was determined and it was therefore concluded that the power tiller is the most appropriate field machinery for tillage operations such as puddling, leveling on lowland rice production in Nigeria. 展开更多
关键词 MECHANIZATION rice production power tiller.
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