Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_...Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(5)(PPh_(3))}(2)(R=2-cyanobenzyl),were synthesized and characterized by infrared spectroscopy,UV-Vis spectroscopy,single-crystal diffraction,powder X-ray diffraction,etc.Their performances as photocatalysts for H_(2)production through water splitting were evaluated.The results showed that 316.8μmol of H_(2)was produced on compound 1 after 3 h of illumination,with a catalytic efficiency of 25.1μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 36.8.The replacement of carbonyl with PPh3 could significantly improve the catalytic performance of the complex,and 705.0μmol of H_(2)was produced on 2 after 3 h of illumination,with a catalytic efficiency of 37.9μmol·mg^(-1)·h^(-1)and a TON of 81.8.CCDC:2515700,1;2515702,1′;2515701,2.展开更多
提取练习效应(Retrieval Practice Effect,RPE)的研究揭示了提取直接促进记忆保持和间接促进后续学习(重学)的关键作用。研究表明,材料难度和提取难度是影响RPE的重要因素,但以往研究未具体区分二者对提取练习直接和间接效应的影响。实...提取练习效应(Retrieval Practice Effect,RPE)的研究揭示了提取直接促进记忆保持和间接促进后续学习(重学)的关键作用。研究表明,材料难度和提取难度是影响RPE的重要因素,但以往研究未具体区分二者对提取练习直接和间接效应的影响。实验1采用2(词对难度:简单,困难)×2(提取支持:无,有)的混合实验设计,考察材料难度和提取难度对提取练习直接效应的影响。实验2引入提取后重学因素,结合行为实验和fNIRS技术区分了材料难度和提取难度对提取练习两种效应的影响。结果发现,相比有提取支持条件,无提取支持条件下提取时颞上回脑区(与提取难度关联)的激活显著增强,且前额皮层脑区(与加工深度关联)在重学阶段表现出更高的激活水平,显著提高了最终记忆成绩。困难词对的提取练习效应弱于简单词对,但无提取支持条件下重学困难词对时,前额叶皮层脑区的激活水平显著更高,有效促进了困难词对提取后的重学效果(记忆成绩显著提高)。以上发现表明,提高提取难度增强了提取练习的直接和间接效应;提取有助于促进困难材料的后续学习,且增加提取难度有助于增强困难材料提取练习的间接效应。展开更多
文摘Two[FeFe]-hydrogenase compounds with 2-cyanobenzyl groups,{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(6)}(1 or 1′,which are the crystalline states from petroleum ether and dichloromethane solution,respectively)and{Fe_(2)[(SCH_(2)CH_(3))(SR)](CO)_(5)(PPh_(3))}(2)(R=2-cyanobenzyl),were synthesized and characterized by infrared spectroscopy,UV-Vis spectroscopy,single-crystal diffraction,powder X-ray diffraction,etc.Their performances as photocatalysts for H_(2)production through water splitting were evaluated.The results showed that 316.8μmol of H_(2)was produced on compound 1 after 3 h of illumination,with a catalytic efficiency of 25.1μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 36.8.The replacement of carbonyl with PPh3 could significantly improve the catalytic performance of the complex,and 705.0μmol of H_(2)was produced on 2 after 3 h of illumination,with a catalytic efficiency of 37.9μmol·mg^(-1)·h^(-1)and a TON of 81.8.CCDC:2515700,1;2515702,1′;2515701,2.
文摘提取练习效应(Retrieval Practice Effect,RPE)的研究揭示了提取直接促进记忆保持和间接促进后续学习(重学)的关键作用。研究表明,材料难度和提取难度是影响RPE的重要因素,但以往研究未具体区分二者对提取练习直接和间接效应的影响。实验1采用2(词对难度:简单,困难)×2(提取支持:无,有)的混合实验设计,考察材料难度和提取难度对提取练习直接效应的影响。实验2引入提取后重学因素,结合行为实验和fNIRS技术区分了材料难度和提取难度对提取练习两种效应的影响。结果发现,相比有提取支持条件,无提取支持条件下提取时颞上回脑区(与提取难度关联)的激活显著增强,且前额皮层脑区(与加工深度关联)在重学阶段表现出更高的激活水平,显著提高了最终记忆成绩。困难词对的提取练习效应弱于简单词对,但无提取支持条件下重学困难词对时,前额叶皮层脑区的激活水平显著更高,有效促进了困难词对提取后的重学效果(记忆成绩显著提高)。以上发现表明,提高提取难度增强了提取练习的直接和间接效应;提取有助于促进困难材料的后续学习,且增加提取难度有助于增强困难材料提取练习的间接效应。
