◇◇新语丝(www.xys.org)(newxys6.com)(groups.google.com/group/xinyusi)◇◇   请教中科院院士候选人陈立东准院士若干科学问题   科研圈院士评选正在如火如荼的顺利展开,可是“钱学森之问“仍待回答, “卡脖子”问题仍需解决。下面希望通过与中科院院士候选人陈立东准院士探讨 若干科学问题,促进院士评选制度的改革,推动相关问题的解决。   1. 今年贵团队以“铜基新型热电材料及其电热输运机制研究”荣获上 海市自然科学一等奖,请问“铜基新型热电材料”新在哪里?   针对贵团队的2012年(Nat. Mater. 11, 422)的“新发现”,2014年 Advanced Energy Materials (4, 1301581) “Are Binary Copper Sulfides Selenides Really New and Promising Thermoelectric Materials?”中明确 指出   Copper sulfides and copper selenides are being investigated as “new”, “promising” thermoelectric materials to be used in low cost devices. We show in this report that these materials have been investigated since 1827, have been patented in 1900, and yet could never be implemented in a product. The most promising binary copper chalcogenides, namely Cu2S and Cu2Se, suffer from major copper ion migrations when exposed to currents and voltages equivalent to the ones present in typical TE devices. This phenomenon may stem from the “liquid-like” property of this superionic conductor. The other potentially appealing phases exhibit severe instability when heated in air and even in nitrogen.   在2020年贵团队自己的综述文章里(Energy Environ. Sci. 13, 3307)也 明确指出   As early as the 1960s, Cu2Se-based materials had been discovered with a peak zT of 1.2 at 1000 K. Over the following decade it was tested and developed by the 3M Corporation, NASA Jet Propulsion Laboratory, Teledyne Energy Systems, and General Atomics Corporation for use in the next-generation radioisotope thermal generators. However, after more than 14 years of effort, this material system was finally abandoned due to the instability problem observed during testing. After the proposal of the PLEC paradigm in 2012, Cu2Se was revisited and rediscovered as a promising TE material on account of its unique liquid-like behavior.   请陈立东准院士明确回答贵团队的“铜基新型热电材料”到底新在哪里?   2. 基于“铜基新型热电材料”的高性能热电器件是否稳定?   上面已经提到铜基热电材料因为其不稳定性而被产业界抛弃,贵团队近年来 花了很大的精力致力于此问题的解决,也发表了多篇高水平文章,例如 “Suppression of atom motion and metal deposition in mixed ionic electronic conductors” (Nature Communications 9, 2910)和 “High-Efficiency and Stable Thermoelectric Module Based on Liquid-Like Materials” (Joule, 3, 1538)。想请教立东准院士,贵团队做的 “铜基新型热电材料”是否已经将前人遇到的“liquid-like”带来的不稳定性 解决了呢?是否能够实现“新型热电材料”的真正应用,从而解决相关领域的 “卡脖子问题”?   3. “Ultrahigh Thermoelectric Performance by Electron and Phonon Critical Scattering in Cu2Se1-xIx”是否还是“Ultrahigh”?   最近贵团队发表了一篇“Thermal Conductivity during Phase Transitions”(Adv. Mater. 1806518, 2018),文中明确指出“In summary, we show that the measurement of thermal   diffusivity can be affected by material’s phase transition with the degree determined by the speed of phase transitions in addition to the well-known increased heat capacity. The extraction of the true thermal conductivity requires removing the contributions from both altered heat capacity and thermal diffusivity during phase transitions, which is well demonstrated in the four selected kinds of phase transition materials (Cu2Se, Cu2S, Ag2S, and Ag2Se) in experiment.”   基于这篇文章,想知道贵团队2013年同样在Adv. Mater. 上发表的 “Ultrahigh Thermoelectric Performance by Electron and Phonon Critical Scattering in Cu2Se1-xIx”是否还是“Ultrahigh”?如果不是,建议立东准 院士能够更正或者撤稿。   希望陈立东准院士能够给所有的院士、准院士们立一个标杆,准确严肃的回 答上述科学问题。   说到院士评选,院士代表了中国最高科研水平,近年来热电新秀北航赵立东 教授在Science连续发表5篇重要成果,请问你们两位立东教授到底谁在热电领域 的学术水平更高,谁的学术水平高,建议谁来评选热电院士。 (XYS20211012) ◇◇新语丝(www.xys.org)(newxys6.com)(groups.google.com/group/xinyusi)◇◇