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Chinese Journal of Electronics 2024年第5期33卷 1181-1187页

作者： Nan HE lei wang Yi TONG College of Electronic and Optical Engineering College of Flexible Electronics (Future Technology) and College of Integrated Circuit Science and Engineering Nanjing University of Posts and Telecommunications Gusu Laboratory of Materials

Three-atoms-type V2C MXene, an emerging class of transition metal carbides, has attracted tremendous attention in the fabrication of advanced memristive devices due to its excellent electrochemical properties. However,the inserted effects and corresponding physical mechanisms of inserting V2C on traditional TiO2-based memristors have not been clearly explored. In this work, exhaustive electrical characterizations of the V2C/TiO2-based devices exhibit enhanced performance（e.g., improved switching stability and lower operating voltages） compared to the TiO2-based counterparts. In addition, the advantaged influences of the inserted V2C have also been studied by means of first-principles calculations, confirming that V2C MXene enables controllable internal ionic process and facilitated formation mechanism of the Ag conductive filaments. This work demonstrates a way to combine experimental and theoretical investigations to reveal the positive effects of introducing V2C MXene on memristor, which is beneficial for fabricating performance-enhanced memristors.

关键词： Performance evaluation Fabrication Memristors Process control Metals Switches Stability analysis Memristor V2C MXene First-principles calculation Switching stability Formation mechanism

The interaction between temperature and precipitation on the potential distribution range of Betula ermanii in the alpine treeline ecotone on the Changbai Mountain

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Forest Ecosystems 2024年第1期11卷 42-51页

作者： Yu Cong Yongfeng Gu wen J.wang lei wang Zhenshan Xue Yingyi Chen Yinghua Jin Jiawei Xu Mai-He Li Hong S.He Ming Jiang Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains Ministry of EducationSchool of Geographical SciencesNortheast Normal UniversityChangchun 130024China School of Natural Resources University of MissouriColumbiaMO 65211USA Swiss Federal Institute for Forest Snow and Landscape Research WSLCH-8903 BirmensdorfSwitzerland School of Life Science Hebei UniversityBaoding 071000China

Alpine treeline ecotones are highly sensitive to climate *** low temperature-determined alpine treeline is expected to shift upwards in response to global ***,little is known about how temperature interacts with other important factors to influence the distribution range of tree species within and beyond the alpine treeline ***,we used a GF-2 satellite image,along with bioclimatic and topographic variables,to develop an ensemble suitable habitat model based on the species distribution modeling algorithms in *** investigated the distribution of suitable habitats for *** under three climate change scenarios(i.e.,low(SSP126),moderate(SSP370)and extreme(SSP585)future emission trajectories)between two consecutive time periods(i.e.,current-2055,and 2055-2085).By 2055,the potential distribution range of *** will expand under all three climate *** medium and high suitable areas will decline under SSP370 and SSP585scenarios from 2055 to ***,under the three climate scenarios,the uppermost altitudes of low suitable habitat will rise to 2,329 m a.s.l.,while the altitudes of medium and high suitable habitats will fall to 2,201 and2,051 m *** 2085,*** promotes the expansion of *** distribution range in Changbai Mountain,and this expansion will be modified by precipitation as climate warming *** interaction between temperature and precipitation plays a significant role in shaping the potential distribution range of *** in the alpine treeline *** study reveals the link between environmental factors,habitat distribution,and species distribution in the alpine treeline ecotone,providing valuable insights into the impacts of climate change on high-elevation vegetation,and contributing to mountain biodiversity conservation and sustainable development.

关键词： Biomod2 Birch Climate change Climate scenarios Habitat suitability Range shift Treeline species

Stall Evolution Mechanism of a Centrifugal Compressor with a Wide-Long Vaneless Diffuser

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Journal of Thermal Science 2024年第3期33卷 899-913页

作者： ZHANG lei KANG Jiacheng LANG Jinhua AN Guangyao ZHANG Qian wang Longyao wang Qifang Department of Power Engineering North China Electric Power UniversityBaoding071003China Hebei Key Laboratory of Low Carbon and High Efficiency Power Generation Technology North China Electric Power UniversityBaoding071003China

The rotating stall mechanism is of high importance for the stability of centrifugal compressors and thermal power *** majority of research concerning this topic has concentrated on the initial stall ***,the evolution of stall cells in wide-long diffusers has not been comprehensively *** this paper,the causes of rotating stall in the wide-long diffuser and the three-dimensional evolution mechanism of stall cells during the stall process were thoroughly *** the stall induction phase,an annulus vortex structure was found in the reverse-flow zone near the hub side of the diffuser outlet,which was the initial form of stall *** whole evolution process of stall cells was divided into three phases as the flow rate *** the initial stall phase,the dynamic equilibrium was built under effects of the impeller wake and the adverse pressure *** a result,the number of stall cells was kept at seven and the size of stall cells remained *** the transition phase,the flow in the diffuser became *** cells extended to the impeller outlet,and the effect of the wake flow was strengthened *** cells started integrating and separating *** a result,the number and propagation speed of stall cells varied periodically at a constant mass flow *** the deep stall phase,the size of stall cells remained unchanged,and the number of stall cells kept at *** study has important practical guidance and engineering value for the high-efficiency design and safe operation of centrifugal compressors.

关键词： centrifugal compressor wide-long vaneless diffuser stall evolution mechanism wake flow

Stress relaxation properties of calcium silicate hydrate:a molecular dynamics study

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第2期25卷 97-115页

作者： Zhicheng GENG Shengwen TANG Yang wang Hubao A Zhen HE Kai WU lei wang State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan430072China Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education School of Materials Science and EngineeringTongji UniversityShanghai200092China College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China

The time-dependent viscoelastic response of cement-based materials to applied deformation is far from fully understood at the atomic *** silicate hydrate(C-S-H),the main hydration product of Portland cement,is responsible for the viscoelastic mechanism of cement-based *** this study,a molecular model of C-S-H was developed to explain the stress relaxation characteristics of C-S-H at different initial deformation states,Ca/Si ratios,temperatures,and water contents,which cannot be accessed *** stress relaxation of C-S-H occurs regardless of whether it is subjected to initial shear,tensile,or compressive deformation,and shows a heterogeneous *** plays a crucial role in the stress relaxation process.A large Ca/Si ratio and high temperature reduce the cohesion between the calcium-silicate layer and the interlayer region,and the viscosity of the interlayer region,thereby accelerating the stress relaxation of *** effect of the hydrogen bond network and the morphology of C-S-H on the evolution of the stress relaxation characteristics of C-S-H at different water contents was elucidated by nonaffine mean squared *** results shed light on the stress relaxation characteristics of C-S-H from a microscopic perspective,bridging the gap between the microscopic phenomena and the underlying atomic-level mechanisms.

关键词： Calcium silicate hydrate(C-S-H) Stress relaxation Ca/Si ratio Temperature Water content Atomic simulation

Evidence of guide field magnetic reconnection in flapping current sheets

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Earth and Planetary Physics 2024年第4期8卷 650-658页

作者： YunTian Hou SuPing Duan lei Dai Chi wang State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Key Laboratory of Solar Activity and Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

Based on current sheet flapping motion on 27 August 2018 in the dusk flank magnetotail,as recorded by instruments aboard Magnetospheric Multiscale(MMS)spacecraft,we present the first study of guide field reconnection observed in the flux rope embedded in kink-like flapping current sheets near the dusk-side flank of the *** more common magnetotail reconnections,which are symmetric,these asymmetric small-scale(λ_(i)~650 km)reconnections were found in the highly twisted current sheet when the direction normal to the sheet changes from the Z direction into the Y *** unique feature of this unusual reconnection is that the reconnection jets are along the Z direction-different from outflow in the X direction,which is the more usual *** vertical reconnection jet is parallel or antiparallel to the up-and-down motion of the tail’s current *** normalized reconnection rate R is estimated to be~*** results indicate that such asymmetric reconnections can significantly enlarge current sheet flapping,with large oscillation *** letter presents direct evidence of guide field reconnection in a highly twisted current sheet,characterized by enlarged current sheet flapping as a consequence of the reconnection outflow.

关键词： magnetic reconnection magnetotail current sheet

A stable implicit nodal integration-based particle finite element method(N-PFEM)for modelling saturated soil dynamics

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2172-2183页

作者： Liang wang Xue Zhang Jingjing Meng Qinghua lei Department of Earth Sciences ETH ZürichZürich8092Switzerland Department of Civil Engineering and Industrial Design University of LiverpoolLiverpoolL693BXUK Department of Civil Environmental and Natural Resources EngineeringLuleåUniversity of TechnologyLuleå97187Sweden Department of Earth Sciences Uppsala UniversityUppsala75105Sweden

In this study,we present a novel nodal integration-based particle finite element method(N-PFEM)designed for the dynamic analysis of saturated *** approach incorporates the nodal integration technique into a generalised Hellinger-Reissner(HR)variational principle,creating an implicit PFEM *** mitigate the volumetric locking issue in low-order elements,we employ a node-based strain smoothing *** discretising field variables at the centre of smoothing cells,we achieve nodal integration over cells,eliminating the need for sophisticated mapping operations after re-meshing in the *** express the discretised governing equations as a min-max optimisation problem,which is further reformulated as a standard second-order cone programming(SOCP)***,pore water pressure,and displacements are simultaneously determined using the advanced primal-dual interior point ***,our numerical model offers improved accuracy for stresses and pore water pressure compared to the displacement-based PFEM *** experiments demonstrate that the N-PFEM efficiently captures both transient and long-term hydro-mechanical behaviour of saturated soils with high accuracy,obviating the need for stabilisation or regularisation techniques commonly employed in other nodal integration-based PFEM *** work holds significant implications for the development of robust and accurate numerical tools for studying saturated soil dynamics.

关键词： Particle finite element method Nodal integration Dynamic saturated media Second-order cone programming(SOCP)

Targeting CD47-SIRPα axis for Hodgkin and non-Hodgkin lymphoma immunotherapy

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Genes & Diseases 2024年第1期11卷 205-217页

作者： Pengcheng Zhao Longyan Xie lei Yu Ping wang School of Life Sciences and Medicine Shandong University of TechnologyZiboShandong 255000China Tongji University Cancer Center Shanghai Tenth People's HospitalSchool of MedicineTongji UniversityShanghai 200092China

The interaction between cluster of differentiation 47(CD47)and signal regulatory proteinα(SiRPa)protects healthy cells from macrophage attack,which is crucial for maintain-ing immune *** of CD47 occurs widely across various tumor cell types and transmits the"don't eat me"signal to macrophages to avoid phagocytosis through binding to *** of the CD47-SIRPa axis is therefore a promising approach for cancer *** is the most common hematological malignancy and is an area of unmet clin-ical *** review mainly described the current strategies targeting the CD47-SIRPa axis,including antibodies,SiRPaFc fusion proteins,small molecule inhibitors,and peptides both in preclinical studies and clinical trials with Hodgkin lymphoma and non-Hodgkin lymphoma.

关键词： Cancer treatment CD47-SIRPαaxis Hodgkin lymphoma Immunotherapy Non-Hodgkin lymphoma

Optimal investment based on relative performance and weighted utility

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 328-342页

作者： wang lei DONG Ying-hui HUA Chun-rong Department of Mathematics Suzhou University of Science and TechnologySuzhou 215009China Changshu Institute of Technology Changshu 215500China

This paper studies the optimal portfolio allocation of a fund manager when he bases decisions on both the absolute level of terminal relative performance and the change value of terminal relative performance comparison to a predefined reference point. We find the optimal investment strategy by maximizing a weighted average utility of a concave utility and an Sshaped utility via a concavification technique and the martingale method. Numerical results are carried out to show the impact of the extent to which the manager pays attention to the change of relative performance related to the reference point on the optimal terminal relative performance.

关键词： relative performance weighted utility S-shaped utility concavification

Local Hamilton type Gradient Estimates and Harnack Inequalities for Nonlinear Parabolic Equations on Riemannian Manifolds

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 539-546页

作者： wen wang Da-peng XIE Hui ZHOU School of Mathematics and Statistics Hefei Normal UniversityHefei 230601China

In this paper,we prove a local Hamilton type gradient estimate for positive solution of the nonlinear parabolic equation ut(x,t)=Δu(x,t)+au(x,t) ln u(x,t)+bu^(α)(x,t),on M×(-∞,∞) with α∈R,where a and b are *** ... 详细信息

关键词： nonlinear parabolic equation gradient estimate Harnack inequality

Maximum Principle for Stochastic Control System with Elephant Memory and Jump Diffusion

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Journal of Systems Science & Complexity 2024年第4期37卷 1392-1412页

作者： FENG Siqi GAO lei wang Guangchen XIAO Hua School of Control Science and Engineering Shandong UniversityJinan 250061China School of Economics Shandong UniversityJinan 250100China School of Mathematics and Statistics Shandong UniversityWeihai 264209China

Motivated by a duopoly game problem,the authors study an optimal control problem where the system is driven by Brownian motion and Poisson point process and has elephant memory for the control variable and the state ***,the authors establish the unique solvability of an anticipated backward stochastic differential equation,derive a stochastic maximum principle,and prove a verification theorem for the aforementioned optimal control ***,the authors generalize these results to nonzero-sum stochastic differential game ***,the authors apply the theoretical results to the duopoly game problem and obtain the corresponding Nash equilibrium solution.

关键词： Anticipated backward stochastic differential equation elephant memory Fréchet derivative maximum principle stochastic delayed differential equation