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

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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)*** present,it is still a great challenge to improve both ferroelectric polarization and leakage current to achieve a high RS on/offratio of ferroelectric ***,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 *** 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 ***,the RS on/offratio reaches 2.5×10^(5),about three orders of magnitude higher than pure PZT *** 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 *** 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

Local search yields a PTAS for fixed-dimensional k-means problem with penalties

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Journal of the Operations Research Society of China 2024年第2期12卷 351-362页

作者： Fan Yuan Da-Chuan Xu dong-Lei Du dong-Mei zhang Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing 100124China Faculty of Management University of New BrunswickFrederictonNB E3B 9Y2Canada School of Computer Science and Technology Shandong Jianzhu UniversityJinan 250101ShandongChina

We study a problem called the k-means problem with penalties(k-MPWP),which is a natural generalization of the typical k-means *** this problem,we have a set D of client points in R^(d),a set F of possible centers in R^(d),and a penalty cost Pj>O for each point j∈*** are also given an integer k which is the size of the center point *** want to find a center point set S■F with size k,choose a penalized subset of clients P■D,and assign every client in D\P to its open *** goal is to minimize the sum of the squared distances between every point in D\P to its assigned centre point and the sum of the penalty costs for all clients in *** using the multi-swap local search technique and under the fixed-dimensional Euclidean space setting,we present a polynomial-time approximation scheme(PTAS)for the k-MPWP.

关键词： Approximation algorithm k-means Local search Penalty

Endomembrane-biased dimerization of ABCG16 and ABCG25 transporters determines their substrate selectivity in ABA-regulated plant growth and stress responses

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Molecular Plant 2024年第3期17卷 478-495页

作者： Yeling Zhou Yuzhu Wang dong zhang Jiansheng Liang institute of Plant and Food Science Department of BiologySchool of Life SciencesSouthern University of Science and Technology(SUSTech)Shenzhen 518055China Key Laboratory of Molecular Design for Plant Cell Factory of Guangdong Higher Education Institutes Southern University of Science and Technology(SUSTech)Shenzhen 518055China jiangsu Key Laboratory of Crop Genetics and Physiology/Co-lnnovation Center for Modern Production Technology of Grain Crops Key Laboratory of Plant Functional Genomics of the Ministry of EducationYangzhou UniversityYangzhou 225009China

ATP-binding cassette(ABC)transporters are integral membrane proteins that have evolved diverse func-tions fulfilled via the transport of various *** Arabidopsis,the G subfamily of ABC proteins is particularly abundant and participates in multiple signaling pathways during plant development and stress *** this study,we revealed that two Arabidopsis ABCG transporters,ABCG16 and ABCG25,engage in ABA-mediated stress responses and early plant growth through endomembrane-specific dimerization-coupled transport of ABA and ABA-glucosyl ester(ABA-GE),*** first revealed that ABCG16 contributes to osmotic stress tolerance via ABA *** specifically,ABCG16 induces cellular ABA efflux in both yeast and plant *** FRET analysis,we showed that ABCG16 forms oblig-atory homodimers for ABA export activity and that the plasma membrane-resident ABCG16 homodimers specifically respond to ABA,undergoing notable conformational ***,we demonstrated that ABCG16 heterodimerizes with ABCG25 at the endoplasmic reticulum(ER)membrane and facilitates the ER entry of ABA-GE in both Arabidopsis and tobacco *** specific responsiveness of the ABCG16-ABCG25 heterodimer to ABA-GE and the superior growth of their double mutant support an inhib-itory role of these twoABCGs in early seedling establishment via regulation of ABA-GE translocation across the ER *** endomembrane-specific analysis of the FRET signals derived from the homo-or heterodimerized ABcG complexes allowed us to link endomembrane-biased dimerization to the transloca-tion of distinct substrates by ABcG transporters,providing a prototypic framework for understanding the omnipotence of ABcG transporters in plant development and stress responses.

关键词： abscisic acid ABCG transporter dimerization endomembrane substrate selectivity

Investigating the Absorption and Desorption Behavior of Methylene Chloride in the Poly(aryl ether ketone) Film with Different Crystallinities

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Chinese Journal of Polymer Science 2024年第2期42卷 239-246,I0009页

作者： Hong-Ru Yang Jin-dong zhang dong-Ting Gao Gang Liu Chun-Hai Chen Jia-Nan Yao Center for Advanced Low-Dimension Materials State Key Laboratory for Modification of Chemical Fibers and Polymer MaterialsCollege of Materials Science and EngineeringDonghua UniversityShanghai201620China

Poly(aryl ether keton e)(PAEK) films with different crystallinities were obtained by controlling the cooling rate,which were subjected to the absorption and desorption of methylene chloride(CH_(2)Cl_(2)).We employed attenuated total reflection Fourier transform infrared(ATR-FTIR)spectroscopy analyses to investigate the diffusion behavior of CH_(2)Cl_(2) in PAEK films with different *** to the Fickian diffusion model,the calculated diffu sion coefficients of CH_(2)Cl_(2) in PAEK films were observed to decrease with increasing *** effect of CH_(2)Cl_(2)absorption and desorption on the mechanical properties of PAEK films with different crystallinity was further analyzed using tensile *** tensile tests exhibited that CH_(2)Cl_(2) has two concurrent effects:plasticization and solvent-induced *** scanning calorimetry(DSC) and wide-angle X-ray diffraction(WXRD) techniques further confirmed solvent-induced crystallization *** results would be beneficial to understand the solvent resistance of PAEK materials and consequently provide the practical application conditions of PAEK with a theoretical basis.

关键词： Poly(aryl ether ketone) Diffusion behavior Infrared spectra Solvent-induced crystallization Mechanical properties

Green Synthesis of Iron(Ⅱ,Ⅲ)-polyphenol Nanoparticles and Their Adsorption of Malachite Green

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 1025-1030页

作者：胡玉 ZHOU Fan zhang Nan PAN Xiaobin LI Shiying zhang dong LI Li 张玲帆 Department of Chemistry and Environmental Engineering Hanjiang Normal UniversityShiyan 442000China Shiyan Hydrological and Water Resources Survey Bureau of Hubei Province Shiyan 442000China School of Chemistry and Molecular Engineering East China University of Science and TechnologyShanghai 200237China

Three kinds of iron nanoparticles(FeNPs)were prepared via green route based on pomegranate(PG),green tea(GT),and mulberry(ML)extracts under ambient *** obtained materials were characterized by scanning electron microscopy(SEM),transmission electronic microscopy(TEM),X-ray energy-dispersive spectrometer(EDS),X-ray diffraction(XRD),fourier transform infrared spectroscopy(FTIR),and X-ray photoelectron spectroscopy(XPS)*** experimental results show that FeNPs were in the form of amorphous iron(Ⅱ,Ⅲ)-polyphenol complex with different dispersity and ***-Fe has the smallest size range of 25-35 nm,PG-Fe has a moderate size-distribution of 30-40 nm,while ML-Fe formed a tuberous net-type with a sheeting ***-Fe displays the highest removal efficiency of 90.2%in 20 min towards cationic dye of malachite green(16.6%by ML-Fe and 69.3%by GT-Fe),which is attributed to its highest polyphenol content,lowest zeta potential,as well as the most Fe^(2+)on the surface of *** removal mechanism was mainly induced by electrostatic adsorption based on pH and zeta potential tests.

关键词： iron nanoparticles pomegranate green tea mulberry adsorption

Research on the Dynamic Compressibility of Polyurethane Microcellular Elastomer and its Application for Impact Resistance

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Chinese Journal of Polymer Science 2024年第8期42卷 1185-1197页

作者： Zhi-Ying Zhao Hao Jiang Xiao-dong Li Xu-dong zhang Xing Su Mei-Shuai Zou School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China

The packaging materials with cushioning performance are used to prevent the internal contents from being damaged by the impact and vibration of external *** polyurethane microcellular elastomers(PUMEs)can absorb energy through cell collapse and molecular chain *** this study,PUMEs with different densities were investigated by scanning electron microscopy,dynamic mechanical analysis and dynamic compression *** exhibited significant im pact resistance and the maximum peak stress attenuation ratio reached 73.33%.The protective equipment was made by PUME with the optimal density of 600 kg/m^(3),and then the acceleration sensing device installed with the same protective equipment fell from a height of 3,5 and 10 m to evaluate the energy-absorbing property and reusability of *** results showed that PUMEs equipment reduced the peak acceleration of the device by 93.84%,with a maximum deviation of 9%between actual test and simulation,and shortened the impact time of first landing by 57.39%.In addition,the equipment PUMEs equipment could effectively reduce the stress on the protected items.

关键词： Polyurethane microcellular elastomer Impact velocity Stress attenuation ratio Impact resistance

The Q-index and Connectivity of Graphs

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Journal of the Operations Research Society of China 2024年第2期12卷 505-519页

作者： Peng-Li zhang Li-Hua Feng Wei-Jun Liu Xiao-dong zhang School of Mathematical Sciences MOE-LSCSHL-MACShanghai Jiao Tong UniversityShanghai 200240China School of Mathematics and Statistics Central South UniversityChangsha 410083HunanChina

A connected graph G is said to be k-connected if it has more than k vertices and remains connected whenever fewer than k vertices are *** this paper,for a connected graph G with sufficiently large order,we present a tight sufficient condition for G with fixed minimum degree to be k-connected based on the *** result can be viewed as a spectral counterpart of the corresponding Dirac-type condition.

关键词： Q-index Minimum degree k-connected

Guest Editorial:Knowledge‐based deep learning system in bio‐medicine

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CAAI Transactions on Intelligence Technology 2024年第4期9卷 787-789页

作者： Yu‐dong zhang Juan Manuel Górriz University of Leicester LeicesterUK University of Granada GranadaSpain

Numerous healthcare procedures can be viewed as medical sector *** the modern era,computers have become indispensable in the realm of medical decision‐***-ever,the common view of computers in the medical field typically extends only to applications that support doctors in diagnosing *** more tightly intertwine computers with the biomedical sciences,professionals are now more frequently utilising knowledge‐driven deep learning systems(KDLS)and their foundational technologies,especially in the domain of neuroimaging(NI).

关键词： learning computer doctor

Influence of friction-lubrication characteristics varying with rolling speed on instability of chatter and slip in cold tandem rolling process

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Journal of Iron and Steel Research(International) 2024年第4期31卷 894-908页

作者： Yan-li Xin Zhi-ying Gao Bo Tian Qing-dong zhang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China

In the high-speed cold tandem rolling process of thin plate,chatter or slip instability gives rise to the deterioration of equipment and product *** instability behavior is closely related to interfacial friction-lubrication con-dition which is generally characterized by the friction ***,with higher and higher speed requirements,the commonly used model of friction coefficient is no longer applicable and accurate.A novel approach is suggested to calculate the speed-dependent friction coefficient,in which the viscosity-pressure-temperature effects of the lubricant,surface roughness states of work rolls and rolled piece are comprehensively involved and the mixed flm lubrication theory is ***,the influences of friction coefficient on the instability of slip and chatter are investigated for a five-stand cold tandem rolling *** one side,the critical friction coefficient for each stand is determined by calculating the corresponding slip factor;on the other hand,the friction coefficient varying with rolling speed is combined with the model of theoretical critical rolling speed presented under constant friction coefficient,so that the speed threshold is ***,the stable and unstable regions corresponding to the rear three stands are individually discussed,and the technical strategies are proposed to suppress both slip and chatter frequently occurring in the actual rolling process.

关键词： Cold tandem rolling:Oil film thickness Speed-dependent friction coefficient-Slip:Chatter