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Nuclear Science and Techniques 2024年第5期35卷 173-185页

作者： he-Lin gong Han Li Dunhui Xiao Sibo Cheng Paris Elite Institute of Technology Shanghai Jiao Tong UniversityShanghai 200240China School of Mathematical Sciences Tongji UniversityShanghai 200092China Department of Computing Data Science InstituteImperial College LondonLondon SW72AZUK

The aging of operational reactors leads to increased mechanical vibrations in the reactor *** vibration of the incore sensors near their nominal locations is a new problem for neutronic field *** field-reconstruction methods fail to handle spatially moving *** this study,we propose a Voronoi tessellation technique in combination with convolutional neural networks to handle this *** from movable in-core sensors were projected onto the same global field structure using Voronoi tessellation,holding the magnitude and location information of the *** convolutional neural networks were used to learn maps from observations to the global *** proposed method reconstructed multi-physics fields(including fast flux,thermal flux,and power rate)using observations from a single field(such as thermal flux).Numerical tests based on the IAEA benchmark demonstrated the potential of the proposed method in practical engineering applications,particularly within an amplitude of 5 cm around the nominal locations,which led to average relative errors below 5% and 10% in the L_(2) and L_(∞)norms,respectively.

关键词： Voronoi tessellation Field reconstruction Nuclear reactors Reactor physics On-line monitoring

Band alignment and polarization engineering inκ-Ga_(2)O_(3)/GaN ferroelectric heterojunction

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Science China(Physics,Mechanics & Astronomy) 2022年第7期65卷 147-152页

作者： Yanting Chen Hongkai Ning Yue Kuang Xing-Xing Yu he-he gong Xuanhu Chen Fang-Fang Ren Shulin Gu Rong Zhang Youdou Zheng Xinran Wang Jiandong Ye School of Electronic Science and Engineering Nanjing UniversityNanjing 210023China

Ferroelectric-semiconductor heterostructures offer an alternative strategy to manipulate polarization towards advanced devices with engineered functionality and improved *** this work,we report on the heteroepitaxial construction,band structure alignment and polarization engineering of the single-phasedκ-Ga_(2)O_(3)/GaN ferroelectric/polar heterojunction.A type-II band alignment is determined at theκ-Ga_(2)O_(3)/GaN polar hetero-interface,with a valence band offset of(1.74±0.1)eV and a conduction band offset of(0.29■0.1)*** the band edge discontinuity,charge dipoles induced by spontaneous polarization lead to the observed band bending with built-in potentials of 0.9 and 0.33 eV,respectively,at theκ-Ga_(2)O_(3)surface andκ-Ga_(2)O_(3)/GaN *** polarization switching properties of ferroelectricκ-Ga_(2)O_(3)are identified with a remanent polarization of approximately 2.7μC/cm^(2)via the direct hysteresis remanent polarization/voltage(P-V)loop *** findings allow the rational design ofκ-Ga_(2)O_(3)ferroelectric/polar heterojunction for the application of power electronic devices,advanced memories and even ultra-low loss negative capacitance transistors.

关键词： wide-bandgap semiconductors ferroelectric polarization band alignment

Room-temperature ferroelectricity in van der Waals SnP_(2)S_(6)

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Frontiers of physics 2024年第4期19卷 113-123页

作者： Chaowei he Jiantian Zhang Li gong Peng Yu State Key Laboratory of Optoelectronic Materials and Technologies Guangzhou Key Laboratory of Flexible Electronic Materials and Wearable Devices Nanotechnology Research Center School of Materials Science and EngineeringSun Yat-sen UniversityGuangzhou 510275China Instrumental Analysis and Research Center Sun Yat-sen UniversityGuangzhou 510275China

Two-dimensional(2D)ferroelectric materials,which possess electrically switchable spontaneous polarization and can be easily integrated with semiconductor technologies,is of utmost importance in the advancement of high-integration low-power *** the experimental discovery of certain 2D ferroelectric materials such as CuInP2S6 and In2Se3,achieving stable ferroelectricity at room temperature in these materials continues to present a significant ***,stable ferroelectric order at room temperature in the 2D limit is demonstrated in van der Waals SnP_(2)S_(6) atom layers,which can be fabricated via mechanical exfoliation of bulk SnP_(2)S_(6) *** polarization is observed in thin SnP_(2)S_(6) of~7 ***,a van der Waals ferroelectric field-effect transistor(Fe-FET)with ferroelectric SnP_(2)S_(6) as top-gate insulator and ptype WTe0.6Se1.4 as the channel was designed and fabricated successfully,which exhibits a clear clockwise hysteresis loop in transfer characteristics,demonstrating ferroelectric properties of SnP_(2)S_(6) atomic *** addition,a multilayer graphene/SnP_(2)S_(6)/multilayer graphene van der Waals vertical heterostructure phototransistor was also fabricated successfully,exhibiting improved optoelectronic performances with a responsivity(R)of 2.9 A/W and a detectivity(D)of 1.4×10^(12) *** results show that SnP_(2)S_(6) is a promising 2D ferroelectric material for ferroelectric-integrated low-power 2D devices.

关键词： two-dimensional ferroelectric materials ferroelectric fieldeffect transistors photodetectors

Theoretical study on magnetocaloric effect and its electric-field regulation in CrI_(3)/metal heterostructure

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 134-141页

作者： Weiwei he Ziming Tang Qihua gong Min Yi Wanlin Guo State Key Laboratory of Mechanics and Control for Aerospace Structures Key Laboratory for Intelligent Nano Materials and Devices of Ministry of EducationInstitute for Frontier ScienceNanjing University of Aeronautics and AstronauticsNanjing 210016China MIIT Key Laboratory of Aerospace Information Materials and Physics College of PhysicsNanjing University of Aeronautics and AstronauticsNanjing 211106China

The extraordinary properties of a heterostructure by stacking atom-thick van der Waals(vdW)magnets have been extensively ***,the magnetocaloric effect(MCE)of heterostructures that are based on monolayer magnets remains to be ***,we deliberate MCE of vd W heterostructure composed of a monolayer CrI_(3)and metal atomic layers(Ag,Hf,Au,and Pb).It is revealed that heterostructure engineering by introducing metal substrate can improve MCE of CrI_(3),particularly boosting relative cooling power to 471.72μJ m^(-2)and adiabatic temperature change to 2.1 K at 5 T for CrI_(3)/*** improved MCE is ascribed to the enhancement of magnetic moment and intralayer exchange coupling in CrI_(3)due to the CrI_(3)/metal heterointerface induced charge *** field is further found to tune MCE of CrI_(3)in heterostructures and could shift the peak temperature by around 10 K in CrI_(3)/Hf,thus manipulating the working temperature window of *** theoretical results could enrich the research on low-dimensional magnetocaloric materials.

关键词： magnetocaloric effect heterostructure metal substrate

Occurrence of dark septate endophytes in Phragmites australis in the Baiyang Lake and their resistance to Cd stress

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Pedosphere 2024年第2期34卷 484-496页

作者： Minghui XU Xia LI Qiannan YE Feng gong Xueli he School of Life Sciences Hebei UniversityBaoding 071002China Key Laboratory of Microbial Diversity Research and Application of hebei Province Hebei UniversityBaoding 071002China

heavy metal pollution poses a serious hazard to human health,and microbial remediation of heavy metals in soil has been widely studied.A group of ascomycetes classified as dark septate endophytes(DSEs)colonize plant roots and benefit host plants under abiotic stress *** this study,Phragmites australis,a common remediation plant in the Baiyang Lake in North China,was *** and roots of *** were collected in typical heavy metal-contaminated sites,and the species diversity and community structure of DSEs in *** roots were *** addition,DSE strains were isolated,cultured,and tested for their tolerance to Cd *** results showed that DSEs occurred extensively in *** roots,forming typical dark septate hyphae,with a total colonization rate of 19.7%–83.1%.Morphological and internal transcribed spacer sequencing analyses were used to identify 10 species within 9 genera of DSE *** these fungi,6 strains with considerable resistance to Cd stress were *** biomasses of Poaceascoma helicoides,Alternaria doliconidium,and Acrocalymma vagum strains increased as the Cd levels *** results can not only help to understand plant-DSE interactions in wetland environments,but also provide a theoretical basis for making full use of DSE fungi to alleviate heavy metal contamination in soil.

关键词： ascomycete colonization rate contaminated site evenness index heavy metal Shannon-Wiener index Simpson index wetland

Molecular dynamics study of hydrogen-induced cracking behavior of ferrite–pearlite gas transmission pipeline steel

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Journal of Iron and Steel Research(International) 2024年第2期31卷 488-500页

作者： Tao-long Xu Si-han Guo gong-zhen he Hao-yu Han Petroleum Engineering School Southwest Petroleum UniversityChengdu610500SichuanChina Sichuan East Gas Transmission Sales Center of Sinopec Natural Gas Branch Wuhan430074HubeiChina

Hydrogen embrittlement of pipelines depends on the hydrogen-induced cracking behavior of the pipeline steel *** on molecular dynamics analysis,the ferrite–cementite(α-Fe/Fe3C)lamellar atomic structure with the Bagaryatskii orientation relationship was established,and stepwise relaxation of the conjugate gradient energy minimization and constant-temperature and constant-pressure relaxation were performed under NPT(the isothermal–isobaric)*** mechanical property curves of theα-Fe/Fe3C models were obtained under different cementite terminal plane structures,and the evolution of the atomic structure was analyzed in *** addition,the influence of different hydrogen concentrations,different temperatures,different strain rates,changes in voids,and different micro-degrees of freedom on the deformation and failure mechanism of the model was investigated,aiming to provide a reliable way to explore the micro-mechanism of macro-cracking behavior of pipeline steel.

关键词： Ferrite-cementite lamellar structure Pipeline steel Failure mechanism Crack propagation Molecular dynamics

A Brief Overview of the Development and Significance of Modern Scientific Medicine in China:Take Chinese Academy of Medical Science and Peking Union Medical College as an Example

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Chinese Medical Sciences Journal 2024年第2期39卷 140-143页

作者： Pu-An Cui Zhe-Xi gong Zhong he School of Humanities and Social Sciences Chinese Academy of Medical Science&Peking Union Medical CollegeBeijing 100730China

Since the early 20th century,China has gradually established a clinical,educational,and research system centered around modern scientific medicine,which has now become the dominant force in China's medical and health system and services,with the construction and development of the Chinese Academy of Medical Sciences and Peking Union Medical College as the most prominent *** scientific medicine in the new era requires close cooperation across multiple disciplines and fields to build a high-quality and efficient medical and health service *** also involves combining the excellent traditional Chinese culture with Western medicine to explore a unique path of modern scientific medicine with Chinese characteristics.

关键词： modern scientific medicine cultural confidence multiple view

A deep learning based fine-grained classification algorithm for grading of visual impairment in cataract patients

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Optoelectronics Letters 2024年第1期20卷 48-57页

作者： JIANG Jiewei ZHANG Yi XIE he YANG Jingshi gong Jiamin LI Zhongwen School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China School of Ophthalmology and Optometry and Eye Hospital Wenzhou Medical UniversityWenzhou 325000China Ningbo Eye Hospital Wenzhou Medical UniversityNingbo 315000China

Recent advancements in artificial intelligence(AI)have shown promising potential for the automated screening and grading of ***,the different types of visual impairment caused by cataracts exhibit similar phenotypes,posing significant challenges for accurately assessing the severity of visual *** address this issue,we propose a dense convolution combined with attention mechanism and multi-level classifier(DAMC_Net)for visual impairment ***,the double-attention mechanism is utilized to enable the DAMC_Net to focus on lesions-related ***,a hierarchical multi-level classifier is constructed to enhance the recognition ability in distinguishing the severities of visual impairment,while maintaining a better screening rate for normal *** addition,a cost-sensitive method is applied to address the problem of higher false-negative rate caused by the imbalanced *** results demonstrated that the DAMC_Net outperformed ResNet50 and dense convolutional network 121(DenseNet121)models,with sensitivity improvements of 6.0%and 3.4%on the category of mild visual impairment caused by cataracts(MVICC),and 2.1%and 4.3%on the category of moderate to severe visual impairment caused by cataracts(MSVICC),*** comparable performance on two external test datasets was achieved,further verifying the effectiveness and generalizability of the DAMC_Net.

关键词： visual classifier algorithm

Novel control strategy for the energy recovery system of a hydraulic excavator

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International Journal of Agricultural and Biological Engineering 2024年第2期17卷 94-101页

作者： Changsheng Liu Qinghua he Qijun Tang Kai Ren Jun gong Daqing Zhang The National Enterprise Research and Development Center Sunward Intelligence Equipment Co.Ltd.Changsha 410131China College of Mechanical and Electrical Engineering Hunan Agricultural UniversityChangsha 410128China College of Eletronical and Information Engineering Hunan UniversityChangsha 410082China

The energy saving of hydraulic excavators is always an essential *** energy recovery system can effectively recover the boom potential energy and rotational kinetic *** on the standard working cycle of hydraulic excavators,a dynamic programming(DP)control strategy for hybrid hydraulic excavators was proposed to recover the boom potential energy and rotational kinetic *** hybrid hydraulic excavator simulation model was built by Simulink *** simulation results indicated that the fuel consumption of hybrid hydraulic excavators using the DP control strategy was about 21.3%lower than that of the conventional hydraulic *** order to experimentally verify the simulation results,an experimental platform for hybrid hydraulic excavators was *** experimental results indicated that the fuel consumption of hybrid hydraulic excavators using the DP control strategy was about 18.9%lower than that of the conventional hydraulic *** paper shows that the DP control strategy applied to hybrid hydraulic excavators can recycle the boom potential energy and rotational kinetic energy,and reduce the fuel consumption of hybrid hydraulic excavators.

关键词： hybrid excavator energy recovery control strategy simulation analysis test platform

Effect of remimazolam vs. propofol on hemodynamics during general anesthesia induction in elderly patients: Single-center, randomized controlled trial

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The Journal of Biomedical Research 2024年第1期38卷 66-75页

作者： Mingfeng he Chanjuan gong Yinan Chen Rongting Chen Yanning Qian Department of Anesthesiology and Perioperative Medicine the First Affiliated Hospital of Nanjing Medical UniversityNanjingJiangsu 210029China

The current study aimed to compare the effects between remimazolam and propofol on hemodynamic stability during the induction of general anesthesia in elderly *** used propofol at a rate of 60 mg/(kg·h)in the propofol group(group P)or remimazolam at a rate of 6 mg/(kg·h)in the remimazolam group(group R)for the induction.A processed electroencephalogram was used to determine whether the induction was successful and when to stop the infusion of the study *** measured when patients entered the operating room(T_(0)),when the induction was successful(T_(1)),and when before(T_(2))and 5 min after successful endotracheal intubation(T_(3)).We found that mean arterial pressure(MAP)was lower at T_(1–3),compared with T_(0) in both groups,but higher at T_(2) in the group R,whileΔMAP_(T0–T2) andΔMAP_(max) were smaller in the group R(ΔMAP_(T0–T2):the difference between MAP at time point T_(0) and T_(2),ΔMAP_(max):the difference between MAP at time point T_(0) and the lowest value from T_(0) to T_(3)).Cardiac index and stroke volume index did not differ between groups,whereas systemic vascular resistance index was higher at T_(1–3) in the group *** findings show that remimazolam,compared with propofol,better maintains hemodynamic stability during the induction,which may be attributed to its ability to better maintain systemic vascular resistance levels.

关键词： remimazolam propofol elderly patients hypotension left ventricular systolic function systematic vascular resistance