Effects of characteristics of fly ash on the properties of geopolymer

The properties of two types of fly ash geopolymers made from class F fly ashes produced in wet bottom and dry bottom boilers were investigated in the present study. The source material used in the geopolymer concrete was activated with sodium hydroxide and sodium silicate solution. The results revealed that the geopolymer produced with wet bottom boiler fly ash(CZ-FA)hardened quickly, and had higher early-age strength and lower shrinkage than the geopolymer produced with dry bottom boiler fly ash(SX-FA). The compressive strength of the two geopolymers made from CZ-FA and SX-FA was 45 MPa and 15 MPa respectively when cured at 60 ℃ and delayed for 14 d. However, after 90 days' delay, the compressive strength of both the samples is almost the same, up to 80 MPa. Nearly 20% volume shrinkage of the samples made from SX-FA was much higher than that made from CZ-FA, which was almost zero. XRD, SEM/EDS and FT-IR were used to analyze the main reason of the differences.     

基于案例法的振荡电路研究与实践

通过案例法对耦合振荡电路、电容三点式振荡电路的原理图进行分析;强调电路的分析过程,对反馈系数、起振条件、振荡频率的计算给出具体分析思路;采用仿真软件对振荡电路中的现象进行分析,在实际应用中取得良好的教学效果。     

汇率双向波动下企业汇率风险管理 ——评《企业风险管理》

正在汇率的双向波动下,企业应对汇率进行风险管理才能更好地促进生产经营,规避风险。一个成熟的企业往往会通过规范财务制度,在财务计划中适时纳入汇率的变动因素,合理使用衍生产品,科学地选择融资币种,实现有效分散汇率波动带来的风险。由上海会计学院主编,经济科学出版社2012年6月出版发行的《企业风险管理》一书,以企业风险管理为研究对象,内容丰富,结构清晰。该     

文化视角下高校科技类博物馆育人路径研究

高校博物馆不仅担负一般博物馆的职能,如收藏展品,举办展览,还传承将大学的文化和精神,丰富大学科学研究和人才培养的教育内涵。本文以高校科技类博物馆为视角,探讨文化视角下高校科技类博物馆育人的内涵,并研究其职能实现路径。     

基于Multisim和LabVIEW的模拟电路虚拟实验平台的设计

随着电子技术的迅猛发展以及相应的课程教学内容的不断更新,传统教学中的实验仪器日益暴露出一些缺点和不足,如果运用LabVIEW虚拟仪器图形化编程平台和Multisim电路仿真软件,则可以在电子计算机上开发并建立虚拟仪器。本次设计将重点对线性模拟电子线路的直流分析、交流分析、瞬态分析等的实现作相关研究,最终实现《模拟电子电路》实验课的教学目标。