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Topological feature engineering for machine learning based halide perovskite materials design

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npj Computational Materials 2022年第1期8卷 1943-1950页

作者： D.Vijay Anand Qiang Xu JunJie Wee Kelin Xia Tze Chien Sum Division of mathematical sciences School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore637371Singapore Division of Physics&Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore637371Singapore

Accelerated materials development with machine learning(ML)assisted screening and high throughput experimentation for new photovoltaic materials holds the key to addressing our grand energy ***-driven ML is envisaged as a decisive enabler for new perovskite materials ***,its full potential can be severely curtailed by poorly represented molecular descriptors(or fingerprints).Optimal descriptors are essential for establishing effective mathematical representations of quantitative structure-property *** we reveal that our persistent functions(PFs)based learning models offer significant accuracy advantages over traditional descriptor based models in organic-inorganic halide perovskite(OIHP)materials design and have similar performance as deep learning *** multiscale simplicial complex approach not only provides a more precise representation for OIHP structures and underlying interactions,but also has better transferability to ML *** results demonstrate that advanced geometrical and topological invariants are highly efficient feature engineering approaches that can markedly improve the performance of learning models for molecular data ***,new structure-property relationships can be established between our invariants and *** anticipate that our molecular representations and featurization models will transcend the limitations of conventional approaches and lead to breakthroughs in perovskite materials design and discovery.

关键词： perovskite halide invariants

A cellulose-based lithium-ion battery separator with regulated ionic transport and high thermal stability for extreme environments

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Nano Research 2025年第1期18卷 315-322页

作者： Kun-Peng Yang Song Xie Zi-Meng Han Hao-Cheng Liu Chong-Han Yin Wen-Bin Sun Zhang-Chi Ling Huai-Bin Yang De-Han Li Qing-Fang Guan Shu-Hong Yu department of Chemistry New Cornerstone Science LaboratoryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials&ChemistryHefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China Institute of Innovative Materials Department of Materials Science and EngineeringDepartment of ChemistrySouthern University of Science and TechnologyShenzhen 518055China

Separators play a critical role in lithium-ion ***,the restrictions of thermal stability and inferior electrical performance in commercial polyolefin separators significantly limit their applications under harsh ***,we report a cellulose-assisted self-assembly strategy to construct a cellulose-based separator massively and *** an ultrahigh ionic conductivity in electrolytes of 3.7 mS·cm^(-1) and the ability to regulate ion transport,the obtained separator is a promising alternative for high-performance lithium-ion *** addition,integrated with high thermal stability,the cellulose-based separator endows batteries with high safety at high temperatures,greatly expanding the application scenarios of energy storage devices in extreme environments.

关键词： lithium-ion batteries bio-inspired materials battery separators cellulose nanofiber ultrahigh ionic conductivity high safety

Astrocytes integrate time and space

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Neural Regeneration Research 2025年第2期20卷 467-468页

作者： Justin Lines department of Biological sciences Columbia UniversityNew YorkNYUSA

Astrocytes read and react to synaptic transmission through tripartite synapses,where the binding of neurotransmitters onto astrocytic receptors triggers an increase in intracellular *** investigations have revealed that astrocytes exhibit two distinct states of intracellular calcium activity:(1)graded subcellular localized clusters with independently active microdomains,likely influenced by nearby synaptic events,and(2)whole-cell astrocyte calcium surges,believed to result from the coordinated activation of multiple ***,astrocyte calcium responses are not solely graded;instead,a spatial threshold of intracellular calcium activity can be overcome to elicit an astrocyte calcium *** these calcium responses,in turn,initiate downstream signaling pathways capable of modifying synaptic communication and overall network *** summary,astrocytes can function as integrators of local synaptic events,actively contributing to information processing within the brain.

关键词： graded integrate instead

ON THE EVOLUTION OF DECAYING ISOTROPIC TURBULENCE

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Acta Mechanica Sinica 2004年第1期20卷 113-116页

作者：孟庆国 department of mathematical and physical sciences National Nature Science Foundation of ChinaBeijing 100085China

A direct numerical simulation is performed on 256~3 grids for decaying isotropic tur- *** total kinematic energy,Taylor micro-scale,Taylor micro-scale Reynolds number and the velocity derivative skewness are *** snapshots of energy spectra and energy transfer spectra are *** measurements verify the DIA predictions:decaying isotropic turbulence has the energy propagation and occupies the final decay *** skewness remains to some level with small variation even in the final decay period.

关键词： Decaying isotropic turbulence direct numerical simulation DIA

On Quadratic Wasserstein Metric with Squaring Scaling for Seismic Velocity Inversion

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Numerical Mathematics(Theory,Methods and Applications) 2023年第2期16卷 277-297页

作者： Zhengyang Li Yijia Tang Jing Chen Hao Wu department of mathematical sciences Tsinghua UniversityBeijing 100084China School of mathematical sciences Shanghai Jiao Tong UniversityShanghai 200240China Division of mathematical sciences School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 639798

The quadraticWasserstein metric has shown its power in comparing prob-ability *** is successfully applied in waveform inversion by generating ob-jective functions robust to cycle skipping and insensitive to data *** an alter-native approach that converts seismic signals to probability densities,the squaring scaling method has good convexity and thus is worth *** this work,we apply the quadratic Wasserstein metric with squaring scaling to regional seismic ***,there may be interference between different seismic phases in a broad time *** squaring scaling distorts the signal by magnifying the unbalance of the mass of different seismic phases and also breaks the linear super-position *** a result,illegal mass transportation between different seismic phases will occur when comparing signals using the quadratic Wasserstein ***,it gives inaccurate Fr´echet derivative,which in turn affects the inver-sion *** combining the prior seismic knowledge of clear seismic phase sep-aration and carefully designing the normalization method,we overcome the above ***,we develop a robust and efficient inversion method based on optimal transport theory to reveal subsurface velocity *** numerical experiments are conducted to verify our method.

关键词： Optimal transport Wasserstein metric waveform inversion seismic velocity inversion squaring scaling

Quantifying multiple-site compositional turnover in an Afrotemperate forest, using zeta diversity

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Forest Ecosystems 2018年第2期5卷 189-197页

作者： Cang Hui Wessel Vermeulen Graham Durrheim Centre for Invasion Biology Department of Mathematical SciencesStellenbosch University mathematical and physical Biosciences African Institute for Mathematical Sciences Garden Route Scientific Services South African National Parks

Background： Species turnover is typically measured by partitioning diversity components into alpha and pairwise beta diversity. However, alpha and beta components cannot express the full spectrum of multiple-site compositional turnover. To this end, zeta diversity has been proposed as an extended framework to allow complete biodiversity partitioning and to measure multiple-site species turnover. We use a zeta-diversity framework to explore the turnover and potential community assembly processes of an African Montane Forest. Methods： Using a 20 m grid, we explore the species turnover in a 4.55 ha forest plot located in the Garden Route National Park of South Africa, with 47 and 27 canopy and sub-canopy tree species in the regional poo We first calculate how zeta diversity declines and how the probability of retention of species with particular occupancies changes with increasing zeta orders （i.e. the number of sites [grid cells] involved in the calculation）. Using null models with row sums and column sums constrained respectively, we explore whether species turnover is driven by mechanisms of ecological differences （species-specific occupancies） or habitat heterogeneity （site-specific alpha diversity and thus environmental filters）. Results： The decline of zeta diversity with zeta order followed a power law; that is, the probability of retention increased with species occupancies, suggesting common species being more likely to be discovered in extra sites. The null model retaining row sums （species＇ occupancy） of the species-by-site matrix recreated perfectly the decline of zeta diversity, while the null model of habitat heterogeneity （retaining column sums） was rejected. This suggests that mechanisms driving species-specific occupancies （i.e. ecological differences between species） dictate the multi-site species turnover in the community. The spatial patterns of zeta diversity revealed little spatial structuring forces, supporting a fine-grain structure in these sou

关键词： Species turnover Diversity partitioning Zeta diversity Community assembly Southern cape forest Afromontane forest

A classical algorithm to mimic quantum decisions

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National Science Review 2019年第4期6卷 608-609页

作者： Mile Gu School of physical and mathematical sciences Nanyang Technological University

In his famous 1982 lecture, Nobel laureate Richard Feynman seeded the idea of quantum computation. He reasoned that the amount of classical information required to describe a quantum system scaled exponentially with its size, and thus could not be efficiently simulated by a classical computer. Indeed, a fairly modest system of 100 quantum bits would already require more information to describe than all the present data storage

关键词： A classical algorithm to mimic quantum decisions

Rational points and zeta functions of some curves over finite fields

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Science China Mathematics 2010年第11期53卷 2855-2863页

作者： WANG Long1, & LUO JinQuan2,3 1department of mathematical sciences, Tsinghua University, Beijing 100084, China 2School of mathematical sciences, Yangzhou University, Yangzhou 225002, China 3Division of mathematical sciences, School of physical and mathematical sciences, Nanyang Technology University, 637371, Singapore department of mathematical sciences Tsinghua University Beijing China School of mathematical sciences Yangzhou University Yangzhou China Division of mathematical sciences School of Physical and Mathematical Sciences Nanyang Technology University Singapore Singapore

In this paper we study the number of rational points on some curves over finite fields. Moreover, zeta functions of the associated function fields are evaluated explicitly.

关键词： exponential sum rational point rational place zeta function

In vivo direct neuronal conversion as a therapeutic strategy for ischemic stroke

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Neural Regeneration Research 2025年第8期20卷 2309-2310页

作者： Takashi Irie Taito Matsuda department of Stem Cell Biology and Medicine Graduate School of Medical SciencesKyushu UniversityFukuokaJapan department of Neurology Neurological InstituteGraduate School of Medical SciencesKyushu UniversityFukuokaJapan

Stroke causes neuronal loss,which ultimately results in persistent neurological ***,stroke was the third-leading cause of death and disability combined in all ages in 2019,after neonatal disorders and ischemic heart *** that year,there were 12.2 million incident strokes,101 million prevalent strokes,and 143 million disability-adjusted life-years due to stroke.

关键词： neonatal death therapeutic