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Enhanced memristor performance via coupling effect of oxygen vacancy and ferroelectric polarization

Journal of Materials Science & Technology 2024年第4期171卷 139-146页

作者： Zhi Yun Yue Zhi dong zhang zhan Jie Wang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

As a new type of nonvolatile memory,the resistive memristor has broad application prospects in in-formation storage and neural computing based on its excellent resistive switching(RS)performance.At present,it is still a great challenge to improve both ferroelectric polarization and leakage current to achieve a high RS on/offratio of ferroelectric memristors.Herein,epitaxial Pb(Zr_(0.40)Ti_(0.60))O_(3)(PZT)thin films with low content Ca doping were deposited on the Nb:SrTiO_(3)substrate to prepare PCZT/NSTO het-erostructures and their RS behaviors were studied.The research findings show that compared with pure PZT film,the ferroelectric polarization of 1-mol%-Ca-doped PZT film is slightly improved,while the leak-age current is increased by three orders of magnitude.Therefore,the RS on/offratio reaches 2.5×10^(5),about three orders of magnitude higher than pure PZT films.The theoretical analysis reveals that the RS behavior of PCZT/NSTO heterostructures is controlled by the PCZT/NSTO interfacial barrier and the space charge-limited current mechanism.Our results demonstrate that the ferroelectricity and electricity of ferroelectric thin films can be improved simultaneously by doping low-content Ca ions to increase the RS performance,which provides a good reference for the development of high-performance ferroelectric memristor devices.

关键词： Ferroelectric memristor Ca-doped PZT Ferroelectric polarization Oxygen vacancies Resistive switching

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New clinical trial design in precision medicine:discovery,development and direction

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Signal Transduction and Targeted Therapy 2024年第4期9卷 1293-1321页

作者： Xiao-Peng Duan Bao-dong Qin Xiao-dong Jiao Ke Liu zhan Wang Yuan-Sheng Zang Department of Medical Oncology Changzheng HospitalNaval Medical UniversityShanghaiChina

In the era of precision medicine,it has been increasingly recognized that individuals with a certain disease are complex and different from each other.Due to the underestimation of the significant heterogeneity across participants in traditional"one-sizefits-all"trials,patient-centered trials that could provide optimal therapy customization to individuals with specific biomarkers were developed including the basket,umbrella,and platform trial designs under the master protocol framework.In recent years,the successive FDA approval of indications based on biomarker-guided master protocol designs has demonstrated that these new clinical trials are ushering in tremendous opportunities.Despite the rapid increase in the number of basket,umbrella,and platform trials,the current clinical and research understanding of these new trial designs,as compared with traditional trial designs,remains limited.The majority of the research focuses on methodologies,and there is a lack of in-depth insight concerning the underlying biological logic of these new clinical trial designs.Therefore,we provide this comprehensive review of the discovery and development of basket,umbrella,and platform trials and their underlying logic from the perspective of precision medicine.Meanwhile,we discuss future directions on the potential development of these new clinical design in view of the"Precision Pro","Dynamic Precision",and"Intelligent Precision".This review would assist trial-related researchers to enhance the innovation and feasibility of clinical trial designs by expounding the underlying logic,which be essential to accelerate the progression of precision medicine.

关键词： clinical approval successive

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Review on development of reduced activated ferritic/martensitic steel for fusion reactor

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Journal of Iron and Steel Research(International) 2022年第9期29卷 1343-1356页

作者： Guo-xing Qiu dong-ping zhan Lei Cao Zhou-hua Jiang School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina Materials Engineering Department Hebei College of Industry and TechnologyShijiazhuang 050091HebeiChina

Materials are stil one of the main technical bottlenecks restricting the development of fusion reactors.Reduced activated ferritic/martensitic steel(RAFM)is considered one of the main candidate structural materials for fusion reactor cladding due to its good radiation resistance and mechanical properties.In the past 40 years,RAFM steel has made considerable progress,but numerous problems remain to be solved.The improvements in RAFM steel in recent years,such as chemical composition optimization,clean preparation technology,radiation performance,and applicable welding technology,were systematically summarized.A systematic review of new RAFM steels was conducted,the development direction of the traditional smelting process was analyzed,and the application of laser additive manufacturing technology to RAFM steel was introduced.The effect of rradiation on the microstructure and mechanical properties of RAFM steel was described,and welding methods of RAFM steel and their research progress were reviewed.Finally,the potential applications of Si,Ti,and Zr in improving the performance of RAFM steel,electroslag remelting technology in clean smelting,heat treatment process in optimizing radiation performance,and laser-beam welding in RAFM welding were prospected and summarized.

关键词： Fusion reactor RAFM steel-Preparation technology Iradiation performance-Welding technology

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Automated identification of steel weld defects,a convolutional neural network improved machine learning approach

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 294-308页

作者： zhan SHU Ao WU Yuning SI Hanlin dong Dejiang WANG Yifan LI School of Mechanics and Engineering Science Shanghai UniversityShanghai 200444China School of Civil Engineering Shanghai Normal UniversityShanghai 201418China Shanghai PinlanData Technology Co. Ltd.Shanghai 200072China

This paper proposes a machine-learning-based methodology to automatically classify different types of steel weld defects,including lack of the fusion,porosity,slag inclusion,and the qualified(no defects)cases.This methodology solves the shortcomings of existing detection methods,such as expensive equipment,complicated operation and inability to detect internal defects.The study first collected percussed data from welded steel members with or without weld defects.Then,three methods,the Mel frequency cepstral coefficients,short-time Fourier transform(STFT),and continuous wavelet transform were implemented and compared to explore the most appropriate features for classification of weld statuses.Classic and convolutional neural network-enhanced algorithms were used to classify,the extracted features.Furthermore,experiments were designed and performed to validate the proposed method.Results showed that STFT achieved higher accuracies(up to 96.63%on average)in the weld status classification.The convolutional neural network-enhanced support vector machine(SVM)outperformed six other algorithms with an average accuracy of 95.8%.In addition,random forest and SVM were efficient approaches with a balanced trade-off between the accuracies and the computational efforts.

关键词： steel weld machine learning convolutional neural network weld defect detection classification task percussion

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Irreducible Representations of GL_(n)(C)of Minimal Gelfand-Kirillov Dimension

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Acta Mathematica Sinica,English Series 2024年第3期40卷 639-657页

作者： zhan Qiang BAI Yang Yang CHEN dong Wen LIU Bin Yong SUN School of Mathematical Sciences Soochow UniversitySuzhou 215006P.R.China School of Sciences JiangnanUniversityWui214122P.R.China School of Mathematical Sciences Zhejiang UniversityHangzhou 310058P.R.China Institute for Advanced Study in Mathematics Zhejiang UniversityHangzhou 310058P.R.China

In this article,by studying the Bernstein degrees and Goldie rank polynomials,we es-tablish a comparison between the irreducible representations of G=GL_(n)(C)possessing the minimal Gelfand-Kirillov dimension and those induced from finite-dimensional representations of the maximal parabolic subgroup of G of type(n-1,1).We give the transition matrix between the two bases for the corresponding coherent families.

关键词： Bernstein degree coherent continuation Gelfand-Kirillov dimension

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Host-induced silencing of MpPar6 confers Myzus persicae resistance in transgenic rape plants

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Journal of Integrative Agriculture 2024年第1期23卷 187-194页

作者： Qi zhang Wenqin zhan Chao Li Ling Chang Yi dong Jiang zhang State Key Laboratory of Biocatalysis and Enzyme Engineering School of Life SciencesHubei UniversityWuhan 430062China Oil Crops Research Institute Chinese Academy of Agricultural SciencesWuhan 430062China Agricultural Genomics Institute at Shenzhen Chinese Academy of Agricultural SciencesShenzhen 518000China

Plant-mediated RNA interference(RNAi)has emerged as a promising technology for insect control.The green peach aphid,Myzus persicae,feeds on over 400 species of host plants.Brassica napus(rape)is the second most important oilseed crop worldwide.Myzus persicae is highly reproductive and causes severe damage to the rape plants due to its quite flexible life cycle.In this study,we tested the RNAi effects of transgenic rape plants on M.persicae.By in vitro feeding M.persicae with artificial diets containing double-stranded RNAs(dsRNAs)targeting seven aphid genes,we identified a new gene encoding the partitioning-defective protein 6(Par6)as the most potent RNAi target.Tissue-and stage-expression analysis of Par6 suggested this gene is highly expressed in the embryo and adult stage of M.persicae.We next generated transgenic rape plants expressing ds Par6 by Agrobacteriummediated transformation and obtained nine independent transgenic lines.Compared to wild-type control plants,transgenic rape lines expressing ds Par6 showed strong resistance to M.persicae.Feeding assays revealed that feeding transgenic rape plants to M.persicae significantly decreased MpPar6 expression and survival rate and impaired fecundity.Furthermore,we showed that the resistance levels to M.persicae are positively correlated with ds Par6 expression levels in transgenic rape plants.Our study demonstrates that transgenic rape plants expressing ds Par6 are efficiently protected from M.persicae.Interfering with the genes involved in embryo development could be the effective RNAi targets for controlling aphids and potentially other insect pests.

关键词： oilseed rape pest control aphid double-stranded RNA RNA interference

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Banded structure control of low carbon microalloyed steel based on oxide metallurgy

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Journal of Iron and Steel Research(International) 2023年第11期30卷 2242-2253页

作者： Yong-kun Yang Jia-yu Zhu Xiao-ming Li Yang Wang dong-ping zhan School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055ShaanxiChina School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina

Banded structure is a common harmful microstructure for low carbon microalloyed steel,which seriously shortens the service life of processed parts.In order to study the effect of oxide metallurgy on improving banded structure,the Ti-Zr deoxidized low carbon microalloyed steel that can play the oxide metallurgical role of inclusion was chosen as the research object,and the inclusion characteristics,microstructure and transverse and longitudinal mechanical properties after hot rolling were analyzed.The results showed the inclusion number density increased in all experimental steels after hot rolling,and a large number of long strip inclusions with aspect ratio greater than 3 appeared along the rolling direction.In addition,after hot rolling,there were element segregation bands in the experimental steels,and granular bainite bands were formed in the element enrichment zone.However,the intragranular ferrite generated in the cooling process destroyed the continuity of granular bainite bands,so that the microstructure anisotropy indexes of experimental steels were small.The mechanical properties analysis showed that the anisotropy of performance was mainly reflected in plasticity and toughness in the experimental steels.Among them,the difference ratio of elongation,section shrinkage and impact energy of No.2 steel was 1.69%,3.87% and 1.69%,respectively,which were less than those of No.1 steel and No.3 steel.The anisotropy of microstructure and mechanical properties of No.2 steel that full played the role of oxide metallurgy were improved,and the banded structure control of low carbon microalloyed steel can be realized by oxide metallurgy technology.

关键词： Low carbon microalloyed steel Hot rolling Banded structure Oxide metallurgy Intragranular ferrite

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Miniaturized, Shared Electric and Magnetic Dipole, Pattern Diversity IoT Antenna for Sub-6GHz Applications

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Chinese Journal of Electronics 2024年

作者： zhan WANG Yuandan dong University of Electronic Science and Technology of China

By using a novel meta-resonator structure, a miniaturized, surface mountable, shared aperture, and hybrid electric/magnetic dipole pattern diversity antenna is proposed for Internet of Things（IoT） applications. By exploring the shared electric（E-dipole） and magnetic dipole（M-dipole） structures, a novel T-shaped split-ring resonator（SRR） with even and odd modes is presented and studied by current distributions and equivalent circuits.Broadside and omnidirectional（monopole-like） patterns are achieved by exciting the M-dipole and E-dipole modes of the T-shaped SRR, respectively. To validate the proposed design, this shared aperture metamaterial-inspired pattern diversity antenna with a small size of 0.29 λ0× 0.006 λ0× 0.11 λ0is fabricated and measured. The measured overlapped-10 dB bandwidth is from 3.40 to 3.63 GHz（7.0 %, covering the LTE B42 band） and the port isolation is greater than 23 dB. Both two modes achieve a good radiation efficiency better than-0.79 dB（> 83.0 %）.

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The mechanisms of thermal solidification agent promoting steam diversion in heavy oil reservoirs

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Petroleum Science 2024年第3期21卷 1902-1914页

作者： zhan-Xi Pang Qian-Hui Wang Qiang Meng Bo Wang dong Liu State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum (Beijing) Liaohe Oilfield Institute CNPC China Henan Oilfield Institute Sinopec China Tianjin Branch of China National Offshore Oil Company (CNOOC) Ltd.

At high cycles of steam huff & puff, oil distribution in reservoirs becomes stronger heterogeneity due to steam channeling. Thermal solidification agent can be used to solve this problem. Its solution is a lowviscosity liquid at normal temperature, but it can be solidified above 80°C. The plugging degree is up to 99% at 250°C. The sweep efficiency reaches 59.2%, which is 7.3% higher than pure steam injection. In addition, simultaneous injection of viscosity reducer and/or nitrogen foams can further enhance oil recovery. The mechanism of this technology depends on its strong plugging ability, which changes the flowing pattern of steam to effectively mobilize remaining oil. Viscosity reducer and nitrogen foams further expand the sweep range and extends the effective period. Therefore, thermal solidification agent can plug steam channeling paths and adjust steam flowing direction to significantly enhance oil recovery at high cycles of steam huff & puff.

关键词： Heavy oil reservoir Steam huff & puff Steam channeling Steam diversion Plugging performance Mechanism analysis

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Evolution of inclusion and microstructure in Ti-Zr deoxidized steel during hot compression

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Journal of Iron and Steel Research(International) 2023年第10期30卷 1987-1999页

作者： Yong-kun Yang Jia-yu Zhu Xiao-ming Li Yang Wang Cheng-jun Liu dong-ping zhan School of Metallurgical Engineering Xi'an University of Architecture and TechnologyXi'an 710055ShaanxiChina Key Laboratory for Ecological Metallurgy of Multimetallic Mineral(Ministry of Education) Northeastern UniversityShenyang 110819LiaoningChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

The effects of different hot deformation amounts on the evolution of inclusion and microstructure in Ti-Zr deoxidized steel were studied by utilizing the Thermecmaster-Z hot simulation test machine,automatic scanning electron microscope equipped with energy-dispersive spectrometer,and electron backscattered diffraction.The results indicated that hot deformation amount has no significant effect on the number density of oxide,but the MnS that precipitated on the Ti-Zr oxide surface undergoes extension and breakage,resulting in the changes in oxide aspect ratio.Moreover,the fracture of nitride mainly occurs in the sample with the second pass deformation amount of 42.9%and 71.4%,and the degree of fragmentation of nitride is more serious with the deformation amount increasing.During the hot compression,sulfide undergoes breakage and extension,and with the second pass deformation amount increasing,the breakage and extension of sulfide present a periodic change.Finally,with the increase in hot compression amount,the ferrite types in microstructure change from acicular ferrite and bainitic ferrite to polygonal ferrite,and the ferrite grain size is refined.When the total deformation amount increases from 30%to 80%,the ferrite grain sizes of grain boundary with the misorientation of 4°and 15°decrease from 4.14 and 5.67μm to 3.47 and 4.40μm,respectively.However,when the total deformation amount increases to 80%,the harmful ferrite/pearlite banded structure appears in the micro structure.Refining ferrite grain size and avoiding harmful microstructure are the key for the optimization of hot compression process.

关键词： Hot compression Oxide Nitride Sulfide Microstructure Grain size Ti-Zr deoxidized steel

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