The study determined the relative effectiveness of enriched demonstration and lecture instructional strategies on senior secondary school students’achievement in Chemistry.To achieve this,two research questions and t...The study determined the relative effectiveness of enriched demonstration and lecture instructional strategies on senior secondary school students’achievement in Chemistry.To achieve this,two research questions and three hypotheses were formulated to guide the study.Quasi-experimental design:specifically the pre-test,post-test,nonequivalent and non-randomized control group was adopted for the study.A total sample of one hundred and sixty-six(166)SS 1 students,drawn using multistage sampling technique were used for the study.The instrument used for data collection was Chemistry Achievement Test(CAT,r=0.82).Mean and standard deviation were used to answer the research questions,while analysis of covariance(ANCOVA)was used to test the hypotheses.Findings from the study revealed that:there is significant difference between the achievement of students exposed to two enriched instructional strategies and those exposed to enriched traditional lecture strategy;there is no significant difference between male and female students exposed to the three modes of instructional strategies;and there is no significant interaction effect between the instructional strategies and gender.It was recommended that chemistry educators should focus attention on reforming or enriching the traditional instructional strategies and that chemistry teachers should particularly make use of the enriched demonstration strategy in their classroom interactions,among others.展开更多
随着中国能源结构深化改革的推进,积极发展核能已成为主要趋势。第四代核能系统代表着核电发展的趋势和技术前沿,因此铅冷快中子反应堆的研究在国际上备受关注。基于麻省理工学院(Massachusetts Institute of Technology,MIT)开发的反...随着中国能源结构深化改革的推进,积极发展核能已成为主要趋势。第四代核能系统代表着核电发展的趋势和技术前沿,因此铅冷快中子反应堆的研究在国际上备受关注。基于麻省理工学院(Massachusetts Institute of Technology,MIT)开发的反应堆蒙特卡洛中子输运方程开源软件OpenMC,以铅冷快中子欧洲示范堆(advanced lead fast reactor European demonstrator,ALFRED)为研究对象,选取两种不同的堆芯冷却剂开展铅冷快堆堆芯物理计算。结果表明:在装载相同燃料的情况下,采用铅-铋冷却剂可以提高堆芯的初始反应性271×10-5;堆芯在正常商运状态下具有更高的堆芯有效缓发中子份额;堆芯的中子能谱更宽、更硬;对于燃料中的239 Pu核素,燃烧效果更好。因此,ALFRED堆芯采用铅-铋合金冷却剂时,具有更高的有效增殖因子,有望提高堆芯的控制性和燃耗性能,并有效减少放射性废物的产生。研究成果为铅冷快中子反应堆欧洲示范堆堆芯设计和性能优化提供了有益的参考。展开更多
文摘The study determined the relative effectiveness of enriched demonstration and lecture instructional strategies on senior secondary school students’achievement in Chemistry.To achieve this,two research questions and three hypotheses were formulated to guide the study.Quasi-experimental design:specifically the pre-test,post-test,nonequivalent and non-randomized control group was adopted for the study.A total sample of one hundred and sixty-six(166)SS 1 students,drawn using multistage sampling technique were used for the study.The instrument used for data collection was Chemistry Achievement Test(CAT,r=0.82).Mean and standard deviation were used to answer the research questions,while analysis of covariance(ANCOVA)was used to test the hypotheses.Findings from the study revealed that:there is significant difference between the achievement of students exposed to two enriched instructional strategies and those exposed to enriched traditional lecture strategy;there is no significant difference between male and female students exposed to the three modes of instructional strategies;and there is no significant interaction effect between the instructional strategies and gender.It was recommended that chemistry educators should focus attention on reforming or enriching the traditional instructional strategies and that chemistry teachers should particularly make use of the enriched demonstration strategy in their classroom interactions,among others.
文摘随着中国能源结构深化改革的推进,积极发展核能已成为主要趋势。第四代核能系统代表着核电发展的趋势和技术前沿,因此铅冷快中子反应堆的研究在国际上备受关注。基于麻省理工学院(Massachusetts Institute of Technology,MIT)开发的反应堆蒙特卡洛中子输运方程开源软件OpenMC,以铅冷快中子欧洲示范堆(advanced lead fast reactor European demonstrator,ALFRED)为研究对象,选取两种不同的堆芯冷却剂开展铅冷快堆堆芯物理计算。结果表明:在装载相同燃料的情况下,采用铅-铋冷却剂可以提高堆芯的初始反应性271×10-5;堆芯在正常商运状态下具有更高的堆芯有效缓发中子份额;堆芯的中子能谱更宽、更硬;对于燃料中的239 Pu核素,燃烧效果更好。因此,ALFRED堆芯采用铅-铋合金冷却剂时,具有更高的有效增殖因子,有望提高堆芯的控制性和燃耗性能,并有效减少放射性废物的产生。研究成果为铅冷快中子反应堆欧洲示范堆堆芯设计和性能优化提供了有益的参考。
