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化学教学情景与化学教学情境辨析 总被引:2,自引:1,他引:1
“情境”与“情景”这2个词有时会出现在同一篇文章中。通过对“情境”与“情景”的比较,尤其是通过对化学教学“情境”与化学教学“情景”进行比较,说明二者的区别与联系,以便广大化学教师加深对这一问题的理解和应用。 相似文献
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Recent progress in design of conductive polymers to improve the thermoelectric performance 下载免费PDF全文
Organic semiconductors,especially polymer semiconductors,have attracted extensive attention as organic thermoelectric materials due to their capabilities for flexibility,low-cost fabrication,solution processability and low thermal conductivity.However,it is challenging to obtain high-performance organic thermoelectric materials because of the low intrinsic carrier concentration of organic semiconductors.The main method to control the carrier concentration of polymers is the chemical doping process by charge transfer between polymer and dopant.Therefore,the deep understanding of doping mechanisms from the point view of chemical structure has been highly desired to overcome the bottlenecks in polymeric thermoelectrics.In this contribution,we will briefly review the recently emerging progress for discovering the structure–property relationship of organic thermoelectric materials with high performance.Highlights include some achievements about doping strategies to effectively modulate the carrier concentration,the design rules of building blocks and side chains to enhance charge transport and improve the doping efficiency.Finally,we will give our viewpoints on the challenges and opportunities in the field of polymer thermoelectric materials. 相似文献
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以9,9-双-(3-R-4-氨基苯基)芴(R=H,CH3,F)和1,4-双-(4′-溴苯酰基)苯为单体,通过BuchwaldHartwig交叉偶联反应,缩聚合成了芴基Cardo型聚亚胺酮(PIKF).利用MS软件对其分子结构进行模拟,并通过1H NMR和FTIR等方法进行表征,结果与目标产物吻合.利用凝胶渗透色谱(GP... 相似文献
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利用超高效液相色谱串联质谱技术检测啤酒原料麦芽中的赤霉酸(Gibberellic acid,GA3)。样品由乙腈/水(80/20)提取后,经Oasis MAX固相萃取柱净化,以甲醇-甲酸水为流动相,梯度洗脱下,经选择离子模式(SIR)检测。结果表明,赤霉酸在ACQUITY UPLCTMBEH C18色谱柱上(2.1mm×100mm,1.7μm)得到较好分离,回收率为70%—78%,检出限0.6μg/L,RSD≤8.9%,该方法适用于麦芽等复杂体系中微量赤霉酸的检测。 相似文献
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环境胶体在自然界广泛存在,由于具有很强的反应性和迁移性,环境胶体可作为放射性核素在环境中传输的载体,在放射性核素迁移过程中扮演重要的角色.环境胶体与放射性核素的相互作用对核环境安全和核应急意义重大.近年来,相关问题受到越来越多的关注,成为环境放射化学领域研究的热点.本文针对放射性废物处置环境中的典型胶体,综述了环境胶体与放射性核素相互作用的研究进展,探讨了环境胶体的来源、稳定性和迁移性,介绍了开展胶体相关研究的常见方法,分析了环境胶体对放射性核素环境迁移行为的影响,以期为全面、深入地认识环境胶体和放射性核素的地球化学行为提供参考. 相似文献
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