压电材料具有作动迅速、易于制备和能耗低等优点,使用压电材料对结构进行振动控制能够改善结构性能,研究发现,压电材料的分布能够显著影响控制效果,许多学者使用拓扑优化技术对压电材料或控制电压的布局进行优化。在压电智能结构拓扑优...压电材料具有作动迅速、易于制备和能耗低等优点,使用压电材料对结构进行振动控制能够改善结构性能,研究发现,压电材料的分布能够显著影响控制效果,许多学者使用拓扑优化技术对压电材料或控制电压的布局进行优化。在压电智能结构拓扑优化中,引入多种控制系数作为设计变量,能够获得更大设计空间,进一步提升控制效率。本文基于离散材料优化方法DMO(Discrete Material Optimization)研究了简谐激励作用下压电层控制系数最优分布问题。使用速度负反馈控制策略进行主动控制,选取能够有效衡量结构振动程度的动柔度作为目标函数,设计变量为每对压电传感器和压电致动器的速度负反馈控制系数,使用伴随变量法进行灵敏度分析,最后给出了两个数值算例来验证所提方法的正确性。展开更多
Correction to:Nano-Micro Letters(2025)17:191 https://doi.org/10.1007/s40820-025-01702-7 Following the publication of the original article[1],the authors reported an error in Fig.3(b),and the figure legend was reversed...Correction to:Nano-Micro Letters(2025)17:191 https://doi.org/10.1007/s40820-025-01702-7 Following the publication of the original article[1],the authors reported an error in Fig.3(b),and the figure legend was reversed.The correct Fig.3 has been provided in this orrection.展开更多
The 128.6-m-thick,shale-dominated Klimoli,Wulalike and Lashizhong formations exposed at the Hatuke Creek Section in the Zhuozishan area of Inner Monglia,North China,have been investigated for conodonts.Detailed strati...The 128.6-m-thick,shale-dominated Klimoli,Wulalike and Lashizhong formations exposed at the Hatuke Creek Section in the Zhuozishan area of Inner Monglia,North China,have been investigated for conodonts.Detailed stratigraphical collections of conodonts preserved on bedding planes from graptolitic shales,supplemented by additional discrete conodonts acid-leached from limestones,enable a refinement of the conodont biostratigraphic scheme at this section.Four successive conodont biozones,ranging in age from mid Darriwilian to late Sandbian(Stage slices Dw2–Sa2),are identified:the Dzikodus tablepointensis Biozone,the Eoplacognathus suecicus Biozone,the Pygodus serra Biozone,and the Pygodus anserinus Biozone,in ascending order.New sub-biozones,based on morphotypes of the biozonal index species,are proposed for the Pygodus serra and Pygodus anserinus biozones,providing alternatives when the traditional sub-biozones are unrecognizable.The biozonation is clearly correlated with the coeval Baltoscandian,South American and South China reference standard successions.The diverse preservation states of conodont bedding plane assemblages suggest that the alteration of conodonts in graptolitic shales represents a diagenetic process,challenging the prevailing hypothesis of pre-diagenetic dissolution.This study highlights the crucial role of previously overlooked conodont bedding plane assemblages in correlating Ordovician slope/basin facies shales,which holds great potential for marine shale gas exploration.展开更多
As one of the important components of high-effi-ciency perovskite/silicon series devices,wide-bandgap(WBG)perovskite solar cells(PSCs)have been suffering from serious carrier transport barriers and huge open-circuit v...As one of the important components of high-effi-ciency perovskite/silicon series devices,wide-bandgap(WBG)perovskite solar cells(PSCs)have been suffering from serious carrier transport barriers and huge open-circuit voltage deficit de-rived from non-radiative recombination,especial-ly at the buried interface that are often overlooked.Herein,we combined cationic and anion passiva-tion strategies via ammonium tetra-n-butyl tetrafluoroborate(TBABF_(4))pre-treating the buried interface.Theoretical calculation predicts that the tetrabutylammonium(TBA^(+))organic cations and(tetrafluoroborate)BF_(4)^(−)anions can easily interact with charged interfacial defect.Characterizations further confirm the enhance-ment of carrier transport performance and decrease in defect density upon TBABF4 pre-treat-ment.Consequently,a power conversion efficiency of 21.35%with an ultrahigh filling factor of 84.12%is obtained for 1.68 eV-WBG inverted PSCs.In addition,the device with TBABF4 pre-treatment demonstrates excellent shelf,thermal,and operational stability.展开更多
Aerodynamic evaluation under multi-condition is indispensable for the design of aircraft,and the requirement for mass data still means a high cost.To address this problem,we propose a novel point-cloud multi-condition...Aerodynamic evaluation under multi-condition is indispensable for the design of aircraft,and the requirement for mass data still means a high cost.To address this problem,we propose a novel point-cloud multi-condition aerodynamics transfer learning(PCMCA-TL)framework that enables aerodynamic prediction in data-scarce sce-narios by transferring knowledge from well-learned scenarios.We modified the PointNeXt segmentation archi-tecture to a PointNeXtReg+regression model,including a working condition input module.The model is first pre-trained on a public dataset with 2000 shapes but only one working condition and then fine-tuned on a multi-condition small-scale spaceplane dataset.The effectiveness of the PCMCA-TL framework is verified by comparing the pressure coefficients predicted by direct training,pre-training,and TL models.Furthermore,by comparing the aerodynamic force coefficients calculated by predicted pressure coefficients in seconds with the correspond-ing CFD results obtained in hours,the accuracy highlights the development potential of deep transfer learning in aerodynamic evaluation.展开更多
We perform a comprehensive study of the electron-doped t-t′-J model on cylinders with density matrix renormalization group(DMRG).We conduct a systematic study on the finite-size and boundary condition effects on t-t...We perform a comprehensive study of the electron-doped t-t′-J model on cylinders with density matrix renormalization group(DMRG).We conduct a systematic study on the finite-size and boundary condition effects on t-t′-J model on cylinders.Periodic and anti-periodic boundary conditions are implemented along the circumference direction,with the system’s width extending up to as large as 8 lattice units.We study doping levels of 1/6,1/8,and 1/12,which represent the most interesting region in the phase diagram of electron-doped cuprates.We find that for width-4 and width-6 systems,the ground state for fixed doping switches between anti-ferromagnetic Neel state and stripe state under different boundary conditions and system widths,indicating the presence of large finite size effect in the t-t′-J model.We also have a careful analysis of the d-wave pairing correlations which also change quantitatively with boundary conditions and widths of the system.However,the pairing correlations are enhanced when the system becomes wider for all dopings,suggesting the existence of possible long-range superconducting order in the thermodynamic limit.The width-8 results are found to be dependent on the starting state in the DMRG calculation for the kept states we can reach.For the width-8 system,only Neel(stripe)state can be stabilized in DMRG calculation for 1/12(1/6)doping,while both stripe and Neel states are stable in the DMRG sweep for 1/8 doping,regardless of the boundary conditions.These results indicate that 1/8 doping is likely to lie on the boundary of a phase transition between the Neel phase with lower doping and the stripe phase with higher doping,consistent with the previous study.The sensitivity of the ground state on boundary conditions and size observed for narrow systems is similar to that found in the t′-Hubbard model,where the t′term introduces frustration and makes the stripe state fragile.The study of different boundary conditions provides a useful tool to check the finite size effect in the future DMRG calculations.展开更多
文摘压电材料具有作动迅速、易于制备和能耗低等优点,使用压电材料对结构进行振动控制能够改善结构性能,研究发现,压电材料的分布能够显著影响控制效果,许多学者使用拓扑优化技术对压电材料或控制电压的布局进行优化。在压电智能结构拓扑优化中,引入多种控制系数作为设计变量,能够获得更大设计空间,进一步提升控制效率。本文基于离散材料优化方法DMO(Discrete Material Optimization)研究了简谐激励作用下压电层控制系数最优分布问题。使用速度负反馈控制策略进行主动控制,选取能够有效衡量结构振动程度的动柔度作为目标函数,设计变量为每对压电传感器和压电致动器的速度负反馈控制系数,使用伴随变量法进行灵敏度分析,最后给出了两个数值算例来验证所提方法的正确性。
基金supported in part by STI 2030-Major Projects under Grant 2022ZD0209200in part by Beijing Natural Science Foundation-Xiaomi Innovation Joint Fund (L233009)+4 种基金in part by National Natural Science Foundation of China under Grant No. 62374099in part by the Tsinghua-Toyota Joint Research Fundin part by the Daikin Tsinghua Union Programin part by Independent Research Program of School of Integrated Circuits,Tsinghua Universitysponsored by CIE-Tencent Robotics X Rhino-Bird Focused Research Program
文摘Correction to:Nano-Micro Letters(2025)17:191 https://doi.org/10.1007/s40820-025-01702-7 Following the publication of the original article[1],the authors reported an error in Fig.3(b),and the figure legend was reversed.The correct Fig.3 has been provided in this orrection.
基金supported by the National Natural Science Foundation of China (Nos. 42572017, 42172037)the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS (Nos. 213107, 173122)the International Geoscience Programme (IGCP) project 735 “Rocks and the Rise of Ordovician Life: Filling knowledge gaps in the Early Palaeozoic biodiversification”
文摘The 128.6-m-thick,shale-dominated Klimoli,Wulalike and Lashizhong formations exposed at the Hatuke Creek Section in the Zhuozishan area of Inner Monglia,North China,have been investigated for conodonts.Detailed stratigraphical collections of conodonts preserved on bedding planes from graptolitic shales,supplemented by additional discrete conodonts acid-leached from limestones,enable a refinement of the conodont biostratigraphic scheme at this section.Four successive conodont biozones,ranging in age from mid Darriwilian to late Sandbian(Stage slices Dw2–Sa2),are identified:the Dzikodus tablepointensis Biozone,the Eoplacognathus suecicus Biozone,the Pygodus serra Biozone,and the Pygodus anserinus Biozone,in ascending order.New sub-biozones,based on morphotypes of the biozonal index species,are proposed for the Pygodus serra and Pygodus anserinus biozones,providing alternatives when the traditional sub-biozones are unrecognizable.The biozonation is clearly correlated with the coeval Baltoscandian,South American and South China reference standard successions.The diverse preservation states of conodont bedding plane assemblages suggest that the alteration of conodonts in graptolitic shales represents a diagenetic process,challenging the prevailing hypothesis of pre-diagenetic dissolution.This study highlights the crucial role of previously overlooked conodont bedding plane assemblages in correlating Ordovician slope/basin facies shales,which holds great potential for marine shale gas exploration.
文摘As one of the important components of high-effi-ciency perovskite/silicon series devices,wide-bandgap(WBG)perovskite solar cells(PSCs)have been suffering from serious carrier transport barriers and huge open-circuit voltage deficit de-rived from non-radiative recombination,especial-ly at the buried interface that are often overlooked.Herein,we combined cationic and anion passiva-tion strategies via ammonium tetra-n-butyl tetrafluoroborate(TBABF_(4))pre-treating the buried interface.Theoretical calculation predicts that the tetrabutylammonium(TBA^(+))organic cations and(tetrafluoroborate)BF_(4)^(−)anions can easily interact with charged interfacial defect.Characterizations further confirm the enhance-ment of carrier transport performance and decrease in defect density upon TBABF4 pre-treat-ment.Consequently,a power conversion efficiency of 21.35%with an ultrahigh filling factor of 84.12%is obtained for 1.68 eV-WBG inverted PSCs.In addition,the device with TBABF4 pre-treatment demonstrates excellent shelf,thermal,and operational stability.
基金supported by the Natural Science Foundation of Hunan Province of China(Grant No.2021JJ10045).
文摘Aerodynamic evaluation under multi-condition is indispensable for the design of aircraft,and the requirement for mass data still means a high cost.To address this problem,we propose a novel point-cloud multi-condition aerodynamics transfer learning(PCMCA-TL)framework that enables aerodynamic prediction in data-scarce sce-narios by transferring knowledge from well-learned scenarios.We modified the PointNeXt segmentation archi-tecture to a PointNeXtReg+regression model,including a working condition input module.The model is first pre-trained on a public dataset with 2000 shapes but only one working condition and then fine-tuned on a multi-condition small-scale spaceplane dataset.The effectiveness of the PCMCA-TL framework is verified by comparing the pressure coefficients predicted by direct training,pre-training,and TL models.Furthermore,by comparing the aerodynamic force coefficients calculated by predicted pressure coefficients in seconds with the correspond-ing CFD results obtained in hours,the accuracy highlights the development potential of deep transfer learning in aerodynamic evaluation.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1405400)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301902),the National Natural Science Foundation of China(Grant No.12274290)the sponsor-ship from Yangyang Development Fund.
文摘We perform a comprehensive study of the electron-doped t-t′-J model on cylinders with density matrix renormalization group(DMRG).We conduct a systematic study on the finite-size and boundary condition effects on t-t′-J model on cylinders.Periodic and anti-periodic boundary conditions are implemented along the circumference direction,with the system’s width extending up to as large as 8 lattice units.We study doping levels of 1/6,1/8,and 1/12,which represent the most interesting region in the phase diagram of electron-doped cuprates.We find that for width-4 and width-6 systems,the ground state for fixed doping switches between anti-ferromagnetic Neel state and stripe state under different boundary conditions and system widths,indicating the presence of large finite size effect in the t-t′-J model.We also have a careful analysis of the d-wave pairing correlations which also change quantitatively with boundary conditions and widths of the system.However,the pairing correlations are enhanced when the system becomes wider for all dopings,suggesting the existence of possible long-range superconducting order in the thermodynamic limit.The width-8 results are found to be dependent on the starting state in the DMRG calculation for the kept states we can reach.For the width-8 system,only Neel(stripe)state can be stabilized in DMRG calculation for 1/12(1/6)doping,while both stripe and Neel states are stable in the DMRG sweep for 1/8 doping,regardless of the boundary conditions.These results indicate that 1/8 doping is likely to lie on the boundary of a phase transition between the Neel phase with lower doping and the stripe phase with higher doping,consistent with the previous study.The sensitivity of the ground state on boundary conditions and size observed for narrow systems is similar to that found in the t′-Hubbard model,where the t′term introduces frustration and makes the stripe state fragile.The study of different boundary conditions provides a useful tool to check the finite size effect in the future DMRG calculations.
