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The dynamic surface evolution of halide perovskites induced by external energy stimulation

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National Science Review 2024年第4期11卷 185-194页

作者： Feiyu Cheng Pengdong Wang Chenzhe Xu Qingliang Liao Suicai Zhang Haochun Sun Wenqiang Fan Guodong Liu Zhiyun Li Yaping Kong Li Wang Fangsen Li Zhuo Kang Yue Zhang Academy for advanced Interdisciplinary Science and Technology State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing beijing Key Laboratory for advanced Energy Materials and technologies Key Laboratory of Advanced Materials and Devices for Post-Moore ChipsMinistry of EducationBeijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology Beijing Vacuum Interconnected Nanotech Workstation(Nano-X) Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of Sciences beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences

Tracking the dynamic surface evolution of metal halide perovskite is crucial for understanding the corresponding fundamental principles of photoelectric properties and intrinsic instability. However, due to the volatility elements and soft lattice nature of perovskites, several important dynamic behaviors remain unclear. Here, an ultra-high vacuum（UHV） interconnection system integrated by surface-sensitive probing techniques has been developed to investigate the freshly cleaved surface of CH3NH3PbBr3in situ under given energy stimulation. On this basis, the detailed three-step chemical decomposition pathway of perovskites has been clarified. Meanwhile, the evolution of crystal structure from cubic phase to tetragonal phase on the perovskite surface has been revealed under energy stimulation. Accompanied by chemical composition and crystal structure evolution, electronic structure changes including energy level position,hole effective mass, and Rashba splitting have also been accurately determined. These findings provide a clear perspective on the physical origin of optoelectronic properties and the decomposition mechanism of perovskites.

关键词： metal halide perovskite external energy stimulation surface dynamic evolution surface electronic structure ultra-high vacuum interconnection system

A high-sensitive and self-selective humanoid mechanoreceptor for spatiotemporal tactile stimuli cognition

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Nano Research 2024年第5期17卷 4400-4409页

作者： Shuxin Bi Xuan Zhao Fangfang Gao Xiaochen Xun Bin Zhao Liangxu Xu Tian Ouyang Qingliang Liao Yue Zhang Academy for advanced Interdisciplinary Science and Technology Beijing Advanced Innovation Center for Materials Genome EngineeringUniversity of Science and Technology(Beijing)Beijing 100083China Key Laboratory of advanced Materials and Devices for Post-Moore Chips Ministry of EducationBeijing Key Laboratory for Advanced Energy Materials and TechnologiesSchool of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

The cognition of spatiotemporal tactile stimuli,including fine spatial stimuli and static/dynamic temporal stimuli,is paramount for intelligent robots to feel their surroundings and complete manipulation tasks.However,current tactile sensors have restrictions on simultaneously demonstrating high sensitivity and performing selective responses to static/dynamic stimuli,making it a challenge to effectively cognize spatiotemporal tactile stimuli.Here,we report a high-sensitive and self-selective humanoid mechanoreceptor(HMR)that can precisely respond to spatiotemporal tactile stimuli.The HMR with PDMS/chitosan@CNTs(PDMS:polydimethylsiloxane;CNT:carbon nanotube)graded microstructures and polyurethane hierarchical porous spacer exhibits high sensitivity of 3790.8 kPa^(-1).The HMR demonstrates self-selective responses to static and dynamic stimuli with mono signal through the hybrid of piezoresistive and triboelectric mechanisms.Consequently,it can respond to spatiotemporal tactile stimuli and generate distinguishable and multi-type characteristic signals.With the assistance of the convolutional neural network,multiple target objects can be easily identified with a high accuracy of 99.1%.This work shows great potential in object precise identification and dexterous manipulation,which is the basis of intelligent robots and natural human-machine interactions.

关键词： mechanoreceptors self-selective high-sensitive spatiotemporal tactile stimuli cognition sensors

Forced boiling of nonazeotropic immiscible mixture in a supercapillary microchannel array for ultra-high heat flux removal with chip junction temperature below 85℃

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Science China(Technological Sciences) 2024年第5期67卷 1364-1380页

作者： SUN Bo BAO YuChen TIAN Tong LI Ji School of Engineering Science University of Chinese Academy of SciencesBeijing100049China Laboratory of advanced Thermal Management technologies School of Engineering ScienceUniversity of Chinese Academy of SciencesBeijing100049China

In this study,a structure-optimized two-phase microchannel heat sink with sintered submicron nucleation sites was developed and tested.The copper-based microchannels had a rectangular cross-section with an equivalent hydraulic diameter of 222μm.The subcooled flow boiling characteristics were comprehensively compared between pure HFE-7100 and a non-azeotropic,immiscible binary mixture of HFE-7100 and water,considering heating areas of 1 and 5 cm^(2).The total heating power input to the test section were 100–1500 and 250–3000 W for a 1 and 5 cm^(2)heat source,respectively,with a flow rate ranging from 50 to150 L/h.Compared to pure HFE-7100,the non-azeotropic immiscible binary mixture of HFE-7100/water in the sintered porous microchannels exhibited a much higher overall heat transfer coefficient and lower power consumption.To maintain the junction temperature of a high power electronic chip below 85℃,the proposed supercapillary microchannel heat sink could effectively dissipate the heat flux of 1275 W/cm^(2)over 1 cm^(2)heat source and 500 W/cm^(2)over 5 cm^(2)heat source.In addition,the volume ratio of the binary mixture strongly influence the two-phase flow heat transfer characteristics.An optimal volume ratio exist in terms of the thermal resistance–pumping power minimization(HFE-7100:water=2:8 is recommended in this study).The findings of this investigation on the flow boiling properties of non-azeotropic immiscible mixtures help fill a gap in the related field.

关键词： microchannel sintered powder coating submicron nucleation cavities nonazeotropic immiscible ultra-high heat flux

New steelmaking process based on clean deoxidation technology

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1249-1262页

作者： Zhongliang Wang Yanping Bao State Key Laboratory of advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

After the converter steelmaking process,a considerable number of ferroalloys are needed to remove dissolved oxygen from the molten steel,but it also forms a lot of oxide inclusions that cannot be completely removed.At the same time,it increases the carbon emis-sions in the steel production process.After years of research,our team have developed a series of clean deoxidation technologies,includ-ing carbon deoxidation,hydrogen deoxidation,and waste plastic deoxidation of molten steel to address the aforementioned issues.In this study,thermodynamic calculations and laboratory experiments were employed to verify that carbon and hydrogen can reduce the total oxygen content in the molten steel melt to below 5×10^(-6) and 10×10^(-6),respectively.An analysis of the deoxidation mechanisms and ef-fects of polyethylene and polypropylene was also conducted.In addition,the applications of carbon deoxidation technology in different steels with the hot-state experiment and industrial production were discussed carefully.The carbon deoxidation experimental results of different steels were as follows:(1)the oxygen content of bearing steel was effectively controlled at 6.3×10^(-6) and the inclusion number density was lowered by 74.73%compared to aluminum deoxidized bearing steel;(2)the oxygen content in gear steel was reduced to 7.7×10^(-6) and a 54.49%reduction of inclusion number density was achieved with almost no inclusions larger than 5μm from the average level of industry gear steels;(3)a total oxygen content of M2 high-speed steel was as low as 3.7×10^(-6).In industrial production practice,car-bon deoxidation technique was applied in the final deoxidation stage for non-aluminum deoxidized bearing steel,and it yielded excellent results that the oxygen content was reduced to below 8×10^(-6) and the oxide inclusions in the steel mainly consist of silicates,along with small amounts of spinel and calcium aluminate.

关键词： clean deoxidation carbon deoxidation hydrogen deoxidation waste plastics deoxidation

Insight into demand-driven preparation of single-atomic mediators for lithium–sulfur batteries

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Journal of Energy Chemistry 2024年第3期90卷 205-219,I0007页

作者： Miaoyu Lu Yifan Ding Zaikun Xue Ziang Chen Yuhan Zou Jingyu Sun College of Energy Soochow Institute for Energy and Materials InnovationsKey Laboratory for Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006JiangsuChina beijing Graphene Institute Beijing 100095China

Lithium-sulfur(Li-S) batteries have attracted considerable attention as one of the most appealing energy storage systems.Strenuous efforts have been devoted to tackling the tremendous challenges,mainly pertaining to the severe shuttle effect,sluggish redox kinetics and lithium dendritic growth.Single-atomic mediators as promising candidates exhibit impressive performance in addressing these intractable issues.Related research often utilizes a trial-and-error approach,proposing solutions to fabricate single-atomic materials with diversified features.However,comprehensive review articles especially targeting demand-driven preparation are still in a nascent stage.Inspired by these considerations,this review summarizes the design of single-atomic mediators based on the application case-studies in LiS batteries and other metal-sulfur systems.Emerging preparation routes represented by chemical vapor deposition technology are introduced in a demand-oriented classification.Finally,future research directions are proposed to foster the advancement of single-atomic mediators in Li-S realm.

关键词： Single-atom catalyst Lithium–sulfur battery Chemical vapor deposition Demand-driven preparation

Ordered Bicontinuous Network Structures Regulated by Orientational Interactions in a Rod-Coil Block Copolymer

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Chinese Journal of Polymer Science 2024年第5期42卷 636-642,I0008页

作者： Xiao-Lin Lyu Shi-Chu Yang An-Qi Xiao Ping-Ping Hou Wei Zhang Hong-Bing Pan Zhi-Hao Shen Xing-He Fan Qi-Feng Zhou beijing National Laboratory for Molecular Sciences Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Key Laboratory of advanced Materials technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou350108China

The rich phase behavior of block copolymers(BCPs)has drawn great attention in recent years.However,the double diamond(DD)phase is rarely obtained because of the competition between the minimization of interfacial energy and packing frustration.Here,a rod-coil BCP containing mesogen-jacketed liquid crystalline polymer is designed to acquire ordered bicontinuous network nanostructures.The reduction of internal energy originating from the orientational interaction among the rod blocks can compensate for the free energy penalty of packing frustration to stabilize the DD structure.The resulting BCP can also experience lamellae-to-DD and double gyroid-to-lamellae transitions by changing the annealing temperature.These results make the rod-coil BCP an excellent candidate for the self-assembly of ordered network structures,demonstrating great potential in nanopatterning and metamaterials.

关键词： Block copolymer Rod-coil Ordered bicontinuous phase Double diamond Double gyroid

Turning point of organoid transplantation:first-in-human trial of iPSC-derived retinal organoid grafting in patients with retinitis pigmentosa

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Science China(Life Sciences) 2024年第5期67卷 1082-1084页

作者： Chang-Jun Zhang Zi-Bing Jin beijing Institute of Ophthalmology Beijing Tongren HospitalCapital Medical UniversityBeijing 100730China

The discovery of induced pluripotent stem cells(iPSCs)has revolutionized the field of disease research,providing a promising platform for studying various conditions.Over the last decade,significant progress has been made in combining iPSCs with other cutting-edge technologies to investigate disease mechanisms and develop potential treatments.

关键词： conditions patients retinitis

Mn-based cathode materials for rechargeable batteries

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Science China Chemistry 2024年第1期67卷 87-105页

作者： Xu Zhang Shiqi Liu Boya Wang Guoqing Wang Haozhe Du Xuanyu Wang Haidong Zhang Shu Zhao Lin Wang Haijun Yu Institute of advanced Battery Materials and Devices Faculty of Materials and ManufacturingBeijing University of TechnologyBeijing 100124China Key Laboratory of advanced Functional Materials Ministry of EducationBeijing University of TechnologyBeijing 100124China Create Energy&Benefit Future Co.Ltd. Beijing 100176China

The rapid expansion of renewable energies asks for great progress of energy-storage technologies for sustainable energy supplies,which raises the compelling demand of high-performance rechargeable batteries.To satisfy the huge demand from the coming energy-storage market,the resource and cost-effectiveness of rechargeable batteries become more and more important.Manganese(Mn)as a key transition element with advantages including high abundance,low cost,and low toxicity derives various kinds(spinels,layered oxides,polyanions,Prussian blue analogs,etc.)of high-performance Mn-based electrode materials,especially cathodes,for rechargeable batteries ranging from Li-ion batteries,Na-ion batteries,aqueous batteries,to multivalent metal-ion batteries.It is anticipated that Mn-based materials with Mn as the major transition-metal element will constitute a flourishing family of Mn-based rechargeable batteries(Mn RBs)for large-scale and differentiated energy-storage applications.On the other hand,several critical issues including Jahn-Teller effect,Mn dissolution,and O release greatly hinder the pace of Mn RBs,which require extensive material optimizations and battery/system improvements.This review aims to provide an investigation about Mn-based materials and batteries for the coming energy-storage demands,with compelling issues and challenges that must be overcome.

关键词： manganese cathode materials Mn-based rechargeable batteries energy storage

Transfer-free chemical vapor deposition graphene for nitride epitaxy: challenges, current status and future outlook

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Science China Chemistry 2024年第3期67卷 824-840页

作者： Xiang Gao Senlin Li Jingfeng Bi Kaixuan Zhou Meng Li Zhongfan Liu Jingyu Sun College of Energy Soochow Institute for Energy and Materials InnovationsSUDA-BGI Collaborative Innovation CenterKey Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006China beijing Graphene Institute Beijing 100095China Xiamen Silan advanced Compound Semiconductor Co.Ltd. Xiamen 361026China

Graphene, a two-dimensional material with outstanding electrical and mechanical properties, has attracted considerable attention in the field of semiconductor technologies due to its potential use as a buffer layer for the epitaxial Ⅲ-nitride growth. In recent years, significant progress has been made in the chemical vapor deposition growth of graphene on various insulating substrates for the nitride epitaxy, which offers a facile, inexpensive, and easily scalable methodology. However, certain challenges are still present in the form of producing high-quality graphene and achieving optimal interface compatibility with Ⅲ-nitride materials.In this review, we provide an overview of the bottlenecks associated with the transferred graphene fabrication techniques and the state-of-the-art techniques for the transfer-free graphene growth. The present contribution highlights the current progress in the transfer-free graphene growth on different insulating substrates, including sapphire, quartz, SiO_(2)/Si, and discusses the potential applications of transfer-free graphene in the Ⅲ-nitride epitaxy. Finally, it includes the prospects of the transfer-free graphene growth for the Ⅲ-nitride epitaxy and the challenges that should be overcome to realize its full potential in this field.

关键词： Transfer-free chemical vapor deposition graphene for nitride epitaxy challenges current status and future outlook graphene