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Collapses-revivals phenomena induced by weak magnetic flux in diamond chain

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Chinese Physics B 2020年第1期29卷 148-155页

作者： na-na chang Wen-Quan Jing Yu Zhang Ai-Xia Zhang Ju-Kui Xue Su-Peng Kou Department of Physics Beijing Normal UniversityBeijing 100875China College of Physics and Electronics Engineering Northwest Normal UniversityLanzhou 730070China

We investigate the quantum dynamical behaviors of bosons in a diamond chain with weak magnetic flux(WMF),including Landau–Zener tunnelling,Bloch oscillations,localization phenomenon,and collapses-revivals *** observed that collapses-revivals phenomena can occur in diamond chain with WMF and cannot exist in the strong magnetic flux case as the previous study(chang N N and Xue J K,2018,***.B 27105203).Induced by WMF,the energy band for the system varies from gapless to gapped *** position of the extrema of probability amplitude for ground state can also be altered by WMF within a single diamond *** a consequence,the transitions between different dynamical behaviors of bosons in diamond chain can be manipulated by WMF,depending on its initial configurations.

关键词： collapses-revivals phenomena Bloch oscillations Landau–Zener tunneling localization phenomenon flat band

A public database of thermoelectric materials and system-identified material representation for data-driven discovery

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npj Computational Materials 2022年第1期8卷 2064-2074页

作者： Gyoung S.na Hyunju chang Korea Research Institute of Chemical Technology DaejeonRepublic of Korea

Thermoelectric materials have received much attention as energy harvesting devices and power ***,discovering novel high-performance thermoelectric materials is challenging due to the structural diversity and complexity of the thermoelectric materials containing alloys and *** the efficient data-driven discovery of novel thermoelectric materials,we constructed a public dataset that contains experimentally synthesized thermoelectric materials and their experimental thermoelectric *** the collected dataset,we were able to construct prediction models that achieved R^(2)-scores greater than 0.9 in the regression problems to predict the experimentally measured thermoelectric properties from the chemical compositions of the ***,we devised a material descriptor for the chemical compositions of the materials to improve the extrapolation capabilities of machine learning *** on transfer learning with the proposed material descriptor,we significantly improved the R^(2)-score from 0.13 to 0.71 in predicting experimental ZTs of the materials from completely unexplored material groups.

关键词： properties alloys system

Scattering-based hybrid network for facial attribute classification

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Frontiers of Computer Science 2024年第3期18卷 105-116页

作者： na LIU Fan ZHANG Liang chang Fuqing DUAN School of Artificial Intelligence Beijing Normal UniversityBeijing 100875China

Face attribute classification(FAC)is a high-profile problem in biometric verification and face *** recent research has been devoted to extracting more delicate image attribute features and exploiting the inter-attribute correlations,significant challenges still *** scattering transform(WST)is a promising non-learned feature *** has been shown to yield more discriminative representations and outperforms the learned representations in certain *** to the image classification task,WST can enhance subtle image texture information and create local deformation *** paper designs a scattering-based hybrid block,to incorporate frequency-domain(WST)and image-domain features in a channel attention manner(Squeezeand-Excitation,SE),termed WS-SE *** with CNN,WS-SE achieves a more efficient FAC performance and compensates for the model sensitivity of the small-scale affine *** addition,to further exploit the relationships among the attribute labels,we propose a learning strategy from a causal *** cause attributes defined using the causalityrelated information can be utilized to infer the effect attributes with a high confidence *** analysis experiments demonstrate the effectiveness of our model,and our hybrid model obtains state-of-the-art results in two public datasets.

关键词： wavelet scattering transform causality-related learning facial attribute classification

Predicting thermoelectric properties from chemical formula with explicitly identifying dopant effects

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npj Computational Materials 2021年第1期7卷 964-974页

作者： Gyoung S.na Seunghun Jang Hyunju chang Korea Research Institute of Chemical Technology DaejeonSouth Korea

Dopants play an important role in synthesizing materials to improve target materials properties or stabilize the *** particular,the dopants are essential to improve thermoelectic performances of the ***,existing machine learning methods cannot accurately predict the materials properties of doped materials due to severely nonlinear relations with their materials ***,we propose a unified architecture of neural networks,called DopNet,to accurately predict the materials properties of the doped *** identifies the effects of the dopants by explicitly and independently embedding the host materials and the *** our evaluations,DopNet outperformed existing machine learning methods in predicting experimentally measured thermoelectric properties,and the error of DopNet in predicting a figure of merit(ZT)was 0.06 in mean absolute *** particular,DopNet was significantly effective in an extrapolation problem that predicts ZTs of unknown materials,which is a key task to discover novel thermoelectric materials.

关键词： materials properties explicitly

Investigations on control algorithm of steady-state cornering and control strategy for dynamical correction in a steer-by-wire system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第6期10卷 900-908页

作者： Ying XU chang-fu ZONG Hsiao-hsiang na Lei LIU Department of Computer Science and Technology Jilin University Changchun 130025 China State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130025 China

To improve the handling performance of a steer-by-wire (SBW) vehicle, a series of control logics are proposed. Firstly, an algorithm for enhancing the maneuvering in steady-state cornering is presented. On this basis, two categories of control strategies are used to dynamically correct and compensate the transient state steering responses and vehicle behaviors. Simulator tests including subjective evaluations and virtual field tests are both conducted to make comprehensive investigations on the series of control logics. The subjective evaluations demonstrate that the SBW vehicle with a specifically selected value of steering sensitivity tends to be more desirable for driving than a conventional one in which a fixed steering ratio exists. The virtual field tests indicate that the control strategies for dynamical correction and compensation could effectively improve the handling per-formances of an SBW vehicle by reducing the work load of drivers, enhancing the track-holding performance, and improving steering response properties.

关键词： Steer-by-wire (SBW) Steady-state cornering Steering sensitivity Dynamical correction

Battlefield dynamic scanning and staring imaging system based on fast steering mirror

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Journal of Systems Engineering and Electronics 2019年第1期30卷 37-56页

作者： chang Tianqing WANG Quandong ZHANG Lei HAO na DAI Wenjun Department of Weapon and Control Army Academy of Armored Forces Center for Assessment and Demonstration Research Academy of Military Sciences Department of Science Research Army Academy of Armored Forces

This paper presents the design of an experimental battlefield dynamic scanning and staring imaging system based on a fast steering mirror(FSM), which is capable of real-time monitoring of hot targets and wide-area reconnaissance of hot regions. First,the working principle and working sequence of the FSM are briefly analyzed. The mathematical model of the FSM system is built by modeling its dynamic and electrical properties, and the rationality of the model is validated by means of model identification. Second,the influence of external sources of disturbance such as the carrier and moment on the control precision of the FSM is effectively suppressed by the jointly controlling of proportional integral(PI)and disturbance observer(DOB), thus realizing a high precision and strong robustness control of the FSM system. Then, this paper designs an experimental prototype and introduces a special optical structure to enable the infrared camera to share the FSM with the visible light camera. Finally, the influence of the velocity difference between the mirror of the FSM and the rotating platform on the imaging quality of the system is experimentally analyzed by using the image sharpness evaluation method based on point sharpness. A good dynamic scanning and staring imaging result is achieved when the velocity of these two components correspond.

关键词： fast steering mirror (FSM) dynamic scanning and staring backscanning compensation disturbance observer (DOB) point sharpness.

Model building for chang-8 low permeability sandstone reservoir in the Yanchang formation of the Xifeng oil field

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Mining Science and Technology 2009年第2期19卷 245-251页

作者： SONG Fan HOU Jia-gen SU Ni-na School of Resources and Information China University of Petroleum Beijing 102249 China

In order to build a model for the chang-8 low permeability sandstone reservoir in the Yanchang formation of the Xifeng oil field,we studied sedimentation and diagenesis of sandstone and analyzed major factors controlling this low permeability *** doing so,we have made clear that the spatial distribution of reservoir attribute parameters is controlled by the spatial distribution of various kinds of sandstone *** taking advantage of many coring wells and high quality logging data,we used regression analysis for a single well with geological conditions as constraints,to build the interpretation model for logging data and to calculate attribute parameters for a single well,which ensured accuracy of the 1-D vertical *** this basis,we built a litho-facies model to replace the sedimentary facies *** addition,we also built a porosity model by using a sequential Gaussian simulation with the lithofacies model as the *** the end,we built a permeability model by using Markov-Bayes simula-tion,with the porosity attribute as the *** results show that the permeability model reflects very well the relative differences between low permeability values,which is of great importance for locating high permeability zones and forecasting zones favorable for exploration and exploitation.

关键词： Xifeng oil field low permeability reservoir attribute parameter Markov-Bayes model permeability model

Interconnections between diabetic corneal neuropathy and diabetic retinopathy:diagnostic and therapeutic implications

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Neural Regeneration Research 2025年第8期20卷 2169-2180页

作者： Mingyi Yu Faith Teo En Ning chang Liu Yu-Chi Liu Tissue Engineering and Stem Cell Group Singapore Eye Research InstituteSingapore Yong Loo Lin School of Medicine National University of SingaporeSingapore Department of Cornea and External Eye Disease Singapore National Eye CenterSingapore Ophthalmology and Visual Sciences Academic Clinical Program Duke-NUS Medical SchoolSingapore

Diabetic corneal neuropathy and diabetic retinopathy are ocular complications occurring in the context of diabetes *** corneal neuropathy refers to the progressive damage of corneal *** retinopathy has traditionally been considered as damage to the retinal ***,growing evidence suggests that diabetic retinopathy is a complex neurovascular disorder resulting from dysfunction of the neurovascular unit,which includes both the retinal vascular structures and neural *** retinopathy is one of the leading causes of blindness and is frequently screened for as part of diabetic ocular ***,diabetic corneal neuropathy is commonly overlooked and underdiagnosed,leading to severe ocular surface *** studies have found that these two conditions tend to occur together,and they share similarities in their pathogenesis pathways,being triggered by a status of chronic *** review aims to discuss the interconnection between diabetic corneal neuropathy and diabetic retinopathy,whether diabetic corneal neuropathy precedes diabetic retinopathy,as well as the relation between the stage of diabetic retinopathy and the severity of corneal *** also endeavor to explore the relevance of a corneal screening in diabetic eyes and the possibility of using corneal nerve measurements to monitor the progression of diabetic retinopathy.

关键词： cornea corneal nerves diabetes diabetic corneal neuropathy diabetic retinopathy retina

Effectiveness of Scutellaria baicalensis Georgi root in pregnancy-related diseases:A review

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Journal of Integrative Medicine 2023年第1期21卷 17-25页

作者： Dan-na Fang chang-wu Zheng Ye-ling Ma Medical College Shaoxing UniversityShaoxing 312000Zhejiang ProvinceChina

The root of Scutellaria baicalensis Georgi,also called Huangqin,is frequently used in traditional Chinese *** ancient China,*** root was used to clear heat,protect the fetus,and avoid a miscarriage for thousands of *** modern times,pregnancy-related diseases can seriously affect maternal and fetal health,but few systematic studies have explored the mechanisms and potential targets of *** root in the treatment of pregnancy-related ***(baicalein,wogonin and oroxylin A)and flavonoid glycosides(baicalin and wogonoside)are the main chemical components in the root of *** study presents the current understanding of the major chemical components in the root of ***,focusing on their traditional uses,potential therapeutic effects and ethnopharmacological relevance to pregnancy-related *** mechanisms,potential targets and experimental models of *** root for ameliorating pregnancy-related diseases,such as recurrent spontaneous abortion,preeclampsia,preterm birth,fetal growth restriction and gestational diabetes mellitus,are highlighted.

关键词： Scutellaria baicalensis Georgi Recurrent spontaneous abortion Preeclampsia Preterm birth Fetal growth restriction Gestational diabetes mellitus