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Chemistry is the force to transform nature. To let people have a proper understanding of chemistry, this popular science teaching team, based on the previously Finding Chemistry in Detective Conan, select creatively words from the lyrics of influential pop songs, such as "blue and white porcelain" and "bubble", as the hot problems for chemistry popular science teaching; based on the chemistry topic of each part, seven interactive episodes of popular science are designed, which are rich in content and popular with readers. 相似文献
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西瓜检测部位差异对近红外光谱可溶性固形物预测模型的影响 总被引:1,自引:0,他引:1
西瓜可溶性固形物含量的无损检测对提升其内部品质十分重要。为实现近红外光谱对小型西瓜表面各部位可溶性固形物含量的准确预测,减小检测部位差异对预测模型的影响,以“京秀”西瓜为研究对象,分别采集赤道、瓜脐和瓜梗三部位的漫透射光谱信息,利用偏最小二乘算法(PLS)建立并比较单一检测部位和混合所有检测部位的西瓜可溶性固形物近红外光谱预测模型,并分别采用连续投影算法(SPA)和竞争性自适应重加权算法(CARS)对西瓜可溶性固形物近红外光谱变量进行特征波长筛选。结果显示,相比于单一检测部位的模型,混合所有检测部位的校正集样本建立的模型取得了较优的预测结果。同时,利用CARS算法筛选的42个特征波长变量建模,对三种检测部位预测集样本的预测结果分别为赤道RP=0.892和RMSEP= 0.684 °Brix,瓜脐RP=0.905和RMSEP= 0.629 °Brix,瓜梗RP=0.899和RMSEP= 0.721 °Brix。模型得到了很大的简化,且预测精度较高。比较发现,利用SPA算法筛选的19个特征波长变量所建模型的预测精度较低。利用三种检测部位的西瓜样本建立的PLS混合预测模型,结合CARS算法进行有效特征波长变量筛选,可提高西瓜可溶性固形物预测模型的精度,实现西瓜表面各部位可溶性固形物含量的准确预测,减小检测部位差异对近红外光谱预测模型的影响。结果为今后开发便携式设备检测西瓜表面各部位可溶性固形含量提供参考依据。 相似文献
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X射线增感屏的图象信息传输特性分析 总被引:1,自引:0,他引:1
本文采用Monte Carlo方法详细模拟了不同能量光子与增感屏的作用过程,对于一种稀土(Gd2O2S:Tb)增感屏,计算了出射可见光子数的概率分布、平均出射光子数、统计因子、X射线检测效率以及DQE等.增感屏出射可见光子数的概率分布曲线均有三个峰,随着入射X射线能量的增加,各峰之间距离增大,相对强弱对比增大;其余各曲线在Gd原子K壳层结合能(50.24keV)附近,均有突变.这些结果提供了增感屏图象信息传输性能的基本参数,为深入研究增感屏及成象系统的量子噪音传输特性提供指导. 相似文献
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Hongjian Zhang Wenjie Liang Hongmei Lu Yunfeng Wu Pei Tian Yuecai Song Hai Xu 《大学化学》2020,35(5):174-179
Finding Chemistry in Detective Conan is a Massive Open Online Course (MOOC) offered by Central South University. Under new coronavirus pneumonia, the curriculum team launched a series of student-centered innovative teaching methods based on the existing MOOC Video teaching resources and curriculum features. At the same time, the advantages of various network information platforms such as MOOC, QQ group and Sojump.com were also introduced to create a wonderful Internet plus classroom, which enhanced students' sense of "learning" and strengthened the teaching of teachers' guiding, promoting students' active learning. 相似文献
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