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Universal insertion of molecules in ionic compounds under pressure

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National Science Review 2024年第1期11卷 120-128页

作者： Feng Peng Yanming Ma Chris J.Pickard hanyu liu Maosheng Miao College of Physics and Electronic Information Luoyang Normal University Department of Chemistry and Biochemistry California State University Northridge State Key Laboratory of Superhard Materials & Key Laboratory of Material Simulation Methods and Software of Ministry of Education College of Physics Jilin University International Center of Future Science Jilin University Department of Materials Science & Metallurgy University of Cambridge Advanced Institute for Materials Research Tohoku University Department of Earth Science University of California Santa Barbara

Using first-principles calculations and crystal structure search methods, we found that many covalently bonded molecules such as H2, N2, CO2, NH3, H2O and CH4may react with NaC l, a prototype ionic solid,and form stable compounds under pressure while retaining their molecular structure. These molecules,despite whether they are homonuclear or heteronuclear, polar or non-polar, small or large, do not show strong chemical interactions with surrounding Na and Cl ions. In contrast, the most stable molecule among all examples, N2, is found to transform into cyclo-N5-anions while reacting with NaC l under high pressures. It provides a new route to synthesize pentazolates, which are promising green energy materials with high energy density. Our work demonstrates a unique and universal hybridization propensity of covalently bonded molecules and solid compounds under pressure. This surprising miscibility suggests possible mixing regions between the molecular and rock layers in the interiors of large planets.

关键词： molecule-solid hybrid materials high-pressure crystal structure prediction density functional theory planet interior

Accuracy Evaluation of Marginalized Unscented Kalman Filter

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Space(Science & Technology) 2023年第1期3卷 597-605页

作者： Han Yan hanyu liu Xiucong Sun Ming Xu National Key Laboratory of Space Intelligent Control Beijing Institute of Control EngineeringBeijingChina Beijing Sun Wise Space Technology Ltd BeijingChina Beihang University BeijingChina

Compared with a conventional unscented Kalman filter(UKF),the recently proposed marginalized unscented Kalman filter(MUKF)uses a partially sampling strategy to achieve similar filter accuracy with fewer sigma points,demonstrating its powerful ability to deal with state estimation with mixed linearity and ***,the hypothesis that the accuracy of MUKF is equivalent to that of UKF is not true for all *** this paper,it is proved that when the state equation is expressed as a differential equation,the accuracy of MUKF is equivalent to that of UKF only when the propagations of the states to be sampled and the states not to be sampled in MUKF are independent of each *** above condition corresponds to a common problem in engineering,which is a system with measurement *** theoretical proof and numerical simulation,it is verified in this paper that for the systems with measurement biases,the differences of the computed means and covariances in filtering recursions between MUKF and UKF are restricted to the same order infinitesimal as the square of the scaling *** sum up,this paper evaluates the accuracy of MUKF,providing references for engineers to choose MUKF or UKF in different systems.

关键词： filtering equation scaling

An application of the A-4DEnVar to coupled parameter optimization

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Acta Oceanologica Sinica 2022年第9期41卷 60-70页

作者： Yantian Gong Kangzhuang Liang Xinrong Wu Qi Shao Wei Li Siyuan liu Guijun Han hanyu liu School of Marine Science and Technology Tianjin UniversityTianjin300072China Key Laboratory of Marine Environmental Information Technology National Marine Data and Information ServiceMinistry of Natural ResourcesTianjin300171China Tianjin Key Laboratory for Oceanic Meteorology Tianjin300074China

In variational methods,coupled parameter optimization(CPO) often needs a long minimization time window(MTW) to fully incorporate observational information,but the optimal MTW somehow depends on the model *** analytical four-dimensional ensemble-variational(A-4DEnVar) considers model nonlinearity well and avoids adjoint *** can theoretically be applied to *** verify the feasibility and the ability of the A-4DEnVar in CPO,“twin” experiments based on A-4DEnVar CPO are conducted for the first time with the comparison of four-dimensional variational(4D-Var).Two algorithms use the same background error covariance matrix and optimization algorithm to control *** experiments are based on a simple coupled oceanatmosphere model,in which the atmospheric part is the highly nonlinear Lorenz-63 model,and the oceanic part is a slab ocean *** results show that both A-4DEnVar and 4D-Var can effectively reduce the error of state variables through ***,two methods produce almost the same results in most cases when the MTW is less than 560 time *** results are similar when the MTW is larger than 560 time steps and less than 880 time *** largest MTW of 4 D-Var and A-4DEnVar are 1 200 time ***,A-4DEnVar is not sensitive to ensemble size when the MTW is less than 720 time steps.A-4DEnVar obtains satisfactory results in the case of highly nonlinear model and long MTW,suggesting that it has the potential to be widely applied to realistic CPO.

关键词： 4D-Var A-4DEnVar coupled parameter optimization “twin”experiments

Structure search of two-dimensional systems using CALYPSO methodology

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Frontiers of physics 2022年第2期17卷 121-134页

作者： Pengyue Gao Bo Gao Shaohua Lu hanyu liu Jian Lv Yanchao Wang Yanming Ma International Center for Computational Method&Software College of PhysicsJilin UniversityChangchun 130012China State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China Center for Green Research on Energy and Environmental Materials(GREEN)and International Center for Materials Nanoarchitectonics(MANA) National Institute for Materials Science1-1 NamikiTsukubaIbaraki 305-0044Japan College of Materials Science and Engineering Zhejiang University of TechnologyHangzhou 310014China International Center of Future Science Jilin UniversityChangchun 130012China

The dimensionality of structures allows materials to be classified into zero-, one-, two-, and threedimensional systems. Two-dimensional (2D) systems have attracted a great deal of attention andtypically include surfaces, interfaces, and layered materials. Due to their varied properties, 2D systemshold promise for applications such as electronics, optoelectronics, magnetronics, and *** design of 2D systems is an area of intensive research because of the rapid development of abinitio structure-searching methods. In this paper, we highlight recent research progress on acceleratingthe design of 2D systems using the CALYPSO methodology. Challenges and perspectives for futuredevelopments in 2D structure prediction methods are also presented.

关键词： two-dimensional(2D)systems CALYPSO structure prediction

A Degradation Type Adaptive and Deep CNN-Based Image Classification Model for Degraded Images

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Computer Modeling in Engineering & Sciences 2024年第1期138卷 459-472页

作者： Huanhua liu Wei Wang hanyu liu Shuheng Yi Yonghao Yu Xunwen Yao School of Information Technology and Management Hunan University of Finance and EconomicsChangsha410205China

Deep Convolutional Neural Networks(CNNs)have achieved high accuracy in image classification tasks,however,most existing models are trained on high-quality images that are not subject to image *** practice,images are often affected by various types of degradation which can significantly impact the performance of *** this work,we investigate the influence of image degradation on three typical image classification CNNs and propose a Degradation Type Adaptive Image Classification Model(DTA-ICM)to improve the existing CNNs’classification accuracy on degraded *** proposed DTA-ICM comprises two key components:a Degradation Type Predictor(DTP)and a Degradation Type Specified Image Classifier(DTS-IC)set,which is trained on existing CNNs for specified types of *** DTP predicts the degradation type of a test image,and the corresponding DTS-IC is then selected to classify the *** evaluate the performance of both the proposed DTP and the DTA-ICMon the Caltech 101 *** experimental results demonstrate that the proposed DTP achieves an average accuracy of 99.70%.Moreover,the proposed DTA-ICM,based on AlexNet,VGG19,and ResNet152,exhibits an average accuracy improvement of 20.63%,18.22%,and 12.9%,respectively,compared with the original CNNs in classifying degraded *** suggests that the proposed DTA-ICM can effectively improve the classification performance of existing CNNs on degraded images,which has important practical implications.

关键词： Image recognition image degradation machine learning deep convolutional neural network

O-GlcNAcylation regulates phagocytosis by promoting Ezrin localization at the cell cortex

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Journal of Genetics and Genomics 2023年第7期50卷 486-496页

作者： Song Yang hanyu liu Hua Ni Lingyu Jiang Mulin Yang Quan Chen Jun Zhou Fan Yu State Key Laboratory of Medicinal Chemical Biology Frontiers Science Center for Cell ResponsesTianjin Key Laboratory of Protein ScienceHaihe Laboratory of Cell EcosystemCollege of Life SciencesNankai UniversityTianjin 300071China CNBG-Nankai Joint Research Center Nankai UniversityTianjin 300071China College of Life and Geographic Sciences Kashi UniversityXinjiang 844000China

O-GlcNAcylation is a post-translational modification that serves as a cellular nutrient sensor and participates in multiple physiological and pathological ***,it remains uncertain whether O-GlcNAcylation is involved in the regulation of ***,we demonstrate a rapid increase in protein OGlcNAcylation in response to phagocytotic *** of the O-GlcNAc transferase or pharmacological inhibition of O-GlcNAcylation dramatically blocks phagocytosis,resulting in the disruption of retinal structure and *** studies reveal that the O-GlcNAc transferase interacts with Ezrin,a membrane-cytoskeleton linker protein,to catalyze its *** data further show that Ezrin OGlcNAcylation promotes its localization to the cell cortex,thereby stimulating the membrane-cytoskeleton interaction needed for efficient *** findings identify a previously unrecognized role for protein O-GlcNAcylation in phagocytosis with important implications in both health and diseases.

关键词： O-GlcNAcylation Phagocytosis Retinal pigment epithelium Ezrin Cytoskeleton

Predicting the structure and stability of titanium oxide electrides

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npj Computational Materials 2018年第1期4卷 63-68页

作者： Xin Zhong Meiling Xu Lili Yang Xin Qu Lihua Yang Miao Zhang hanyu liu Yanming Ma Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education Jilin Normal UniversityChangchun 130103China National Demonstration Center for Experimental Physics Education Jilin Normal UniversitySiping 136000China Beijing Computational Science Research Center Beijing 100193China School of Physics and Electronic Engineering Jiangsu Normal UniversityXuzhou 221116China Department of Physics School of ScienceBeihua UniversityJilin 132013China State Key Lab of Superhard Materials&Innovation Center for Computational Physics Methods and Software College of PhysicsJilin UniversityChangchun 130012China International Center for Future Science Jilin UniversityChangchun 130012China

The search for new inorganic electrides has attracted significant attention due to their potential applications in transparent conductors,battery electrodes,electron emitters,as well as catalysts for chemical ***,only a few inorganic electrides have been successfully synthesized thus far,limiting the variety of electride ***,we show the stabilization of inorganic electrides in the Ti-rich Ti–O system through first-principles calculations in conjunction with swarm-intelligence-based CALYPSO method for structure *** the known Ti-rich stoichiometries of Ti_(2)O,Ti_(3)O,and Ti_(6)O,two hitherto unknown Ti_(4)O and Ti_(5)O stoichiometries are predicted to be thermodynamically stable at certain pressure *** found that these Tirich Ti–O compounds are primarily zero-dimensional electrides with excess electrons confined in the atom-sized lattice voids or between the cationic layers playing the role as *** underlying mechanism behind the stabilization of electrides has been rationalized in terms of the excess electrons provided by Ti atoms and their accommodation of excess electrons by multiple cavities and layered atomic *** present results provide a viable direction for searching for practical electrides in the technically important Ti–O system.

关键词： inorganic excess stabilization

Sequestration of helium and xenon via iron-halide compounds in early Earth

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Matter and Radiation at Extremes 2024年第3期9卷 83-88页

作者： Jurong Zhang hanyu liu Changfeng Chen Yanming Ma Key Laboratory of Material Simulation Methods and Software of Ministry of Education and State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China School of Physics and Electronics Shandong Normal UniversityJinan 250014China International Center of Future Science Jilin UniversityChangchun 130012China Department of Physics and Astronomy University of NevadaLas VegasNevada 89154USA

The terrestrial abundance anomalies of helium and xenon suggest the presence of deep-Earth reservoirs of these elements,which has led to great interest in searching for materials that can host these usually unreactive ***,using an advanced crystal structure search approach in conjunction with first-principles calculations,we show that several Xe/He-bearing iron halides are thermodynamically stable in a broad region of P–T phase space below 60 *** results present a compelling case for sequestration of He and Xe in the early Earth and may suggest their much wider distribution in the present Earth than previously *** findings offer insights into key material-based and physical mechanisms for elucidating major geological phenomena.

关键词： halide searching insight

Theory-directed discovery of high-temperature superconductivity in clathrate hydrides at high pressure

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The Innovation 2022年第2期3卷 9-10页

作者： Xin Zhong John S.Tse Russell J.Hemley hanyu liu International Center for Computational Method&Software and State Key Laboratory of Superhard Materials College of PhysicsJilin UniversityChangchun 130012China Department of Physics and Engineering Physics University of SaskatchewanSaskatoon S7N 5E2Canada Departments of Physics Chemistryand Earth and Environmental SciencesUniversity of Illinois ChicagoChicagoIL 60607USA International Center of Future Science Jilin UniversityChangchun 130012China

The search for room-temperature superconductivity has been one of the great challenges in condensedmatter physics ever since the first observation of superconductivity with a critical temperature(T_(c))of 4 K in mercury in *** recent years,we have been witness to the successful observation of superconductivity in highly compressed SH_(3)(T_(c)=203 K at 155 GPa)and classes of clathrate hydrides(e.g.,CaH_(6),YH_(6),YH_(9),LaH_(10)).

关键词： hydrides superconductivity high