Rational design of high-quality 2D/3D perovskite heterostructure crystals for record-performance polarization-sensitive photodetection

Polarization-sensitive photodetection is central to optics applications and has been successfully demonstrated in photodetectors of two-dimensional (2D) materials, such as layered hybrid perovskites; however, achieving high polarization sensitivity in such a photodetector remains extremely challenging. Here, for the first time, we demonstrate a high-performance polarization-sensitive photodetector using single-crystalline 2D/3D perovskite heterostructure, namely, (4-AMP)(MA)₂Pb₃Br₁₀/MAPbBr₃ (MA = methylammonium; 4-AMP = 4-(aminomethyl)piperidinium), which exhibits ultrahigh polarization sensitivity up to 17.6 under self-driven mode. To our knowledge, such a high polarization selectivity has surpassed all of the reported perovskite-based devices, and is comparable to, or even better than, the traditional inorganic heterostructure-based photodetectors. Further studies reveal that the built-in electric field formed at the junction can spatially separate the photogenerated electrons and holes, reducing their recombination rate and thus enhancing the performance for polarization-sensitive photodetection. This work provides a new source of polarization-sensitive materials and insights into designing novel optoelectronic devices.     

广州别称史源

广州城亦称五羊城、羊城。“广州”最早是作为一个州名出现的，三国孙吴黄武五年(226年)分交州之南海四郡置广州，治番禺县，自此始有广州之名。番禺作为广州治所，以后得称为广州城。广州城在历史上还有过番禺城、楚庭、南武城等称法，明清时期广东志书有所记载。     

“None of the Kings on Earth is Their Equal in ʿaṣabiyya”: The Mongols in Ibn Khaldūn's Works

The rise of the Mongol empire was a shock to the Arab world and led many Arab authors to describe these conquerors in decidedly negative terms. The great historian Ibn Khaldūn also discusses the Mongols' rise and their conquests. As a nomadic people they challenged and defeated sedentary populations and founded their own dynasties. Consequently, the Mongol conquests perfectly fit Ibn Khaldūn's theories on ?a?abiyya – which is superior in nomadic groups – and the rise and fall of dynasties. For the Maghrebi historian, the rise of the Mongols was a natural step in the course of history. This consequently colours his view of the Mongols and affects the way he portrays them, especially regarding the themes of violence and religion – recurring themes in many contemporary works dealing with the Mongols – and in his depiction of the Turco-Mongolian conqueror Timur, who is presented in a more favourable light by Ibn Khaldūn than he is in many contemporary works.     

A Ferryman that Builds a Cultural Bridge between China and Belgium

<正>Claire Kirschen is a name that must be mentioned in the China-Belgium diplomatic history. She served as the Belgian Ambassador to China and is now the Belgian General Coordinator for Europalia.China, a biennial international arts festival.     

有关“曹雪芹书箱”问题考两则

<正>一、"一拳石"不能证雪芹书箱为伪造从2009年年初开始,各家红学网络上,关于所谓曹雪芹书箱真假的问题又被很多人提起来。其中,有一个传为某专家主伪的意见引起了我的兴趣。此观点认为书箱是伪造的,核心证据是什么呢?正如红学研究者于鹏所言:问题的核心是与补天有关的"一拳石"出于富竹泉的诗句,此诗被其外孙冒充曹雪芹诗中,而号称曹雪芹书箱的箱子上偏偏有这个"一拳顽石"。     

在爱情与革命的浪漫畅想间——张闻天长篇小说《旅途》及书写策略

张闻天的长篇小说《旅途》是一部充满着精神自居感的爱情与革命的浪漫畅想曲。作者以浪漫主义的精神,确立了书写爱情与革命的新策略:即自居的精神气度凸显主人公王钧凯人格精神的独立品格,赢得爱情的自主权;以共同的叛逆性格与理想的革命诉求彰显双方内在的情感动因;以精神的共鸣升华爱情的崇高感。在环境表现上,以自负的心态化历史事实为心理事实,同构爱情与革命的精神动力。这种强烈的具有精神自居感的浪漫主义书写图式,是五四新文学反帝反封建的浪漫主义精髓的承续,它不仅开启了革命文学的先河,也创造了革命文学的新范式,为后来的革命文学创作提供了可资借鉴的蓝本。     

医学微生物学虚拟试验在实验教学中的应用

根据实验教学的特点,用Photoshop等应用软件制作了"革兰染色法观察细菌形态和染色性"和"肠道病原菌的分离鉴定"两个网络虚拟实验。根据实验中学生需着重掌握的操作技术和易出错的操作环节设置障碍;根据学生需掌握的操作技术的重要性评分;设置后台自动记分和反馈意见。将制作的虚拟实验应用于实验课、学生课后复习、实验考核。学生和教师使用后普遍认为该虚拟实验能真实地展现实验的全过程,能帮助操作者记住实验操作的要点,有趣味性。用于实验考核与实际操作考核结果比较无显著差异(P0.05)。因此,医学微生物学虚拟试验软件应用于实验教学取得了较好效果。     

Red Coral Sculpture

Red coral is a valuable maritime animal resource and has been long cherished by many different nations around the world, This rare species has been proclaimed as a first-grade wildlife under state-level protection by the Chinese Government, for it needs a long growth process and is heavily subject to water temperature and environmental conditions and it is extremely difficult to pick and get it.