检索结果-南通市图书馆

极薄氧化物/6H-SiC结构的电学和光学性质研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

冶金分析 2011年第12期31卷 15-20页

作者： Pincik E Kobayashi H madani m Rusnak J Takahashi m mikula m Brunner R 斯洛伐克科学院物理研究所科学与工业研究所大阪大学斯洛伐克科学院化学、食品技术和应用光化学系

研究了湿化学法(120℃硝酸氧化,还有低温湿法氧化过程和高温退火组合)制备的极薄氧化物/6H-SiC结构的电学和光学性质。用深能阶暂态光谱学(电荷版)分析了电界面性质,用傅里叶变换衰减全反射红外光谱考察了极薄氧化物/6H-SiC结构的光学... 详细信息

研究了湿化学法(120℃硝酸氧化,还有低温湿法氧化过程和高温退火组合)制备的极薄氧化物/6H-SiC结构的电学和光学性质。用深能阶暂态光谱学(电荷版)分析了电界面性质,用傅里叶变换衰减全反射红外光谱考察了极薄氧化物/6H-SiC结构的光学性质。发现界面缺陷结构的强转换依赖于应用的技术条件。

关键词：碳化硅 mOS 硝酸氧化傅里叶变换红外光谱深能阶瞬态光谱

A Simple, Fast and Stabilized Flowing Finite Volume method for Solving General Curve Evolution Equations

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Communications in Computational Physics 2010年第1期7卷 195-211页

作者： Karol mikula Daniel Sevcovic martin Balazovjech Department of mathematics Slovak University of TechnologyRadlinskeho 1181368 BratislavaSlovak Republic Department of Applied mathematics and Statistics Comenius University84248 BratislavaSlovak Republic

A new simple Lagrangian method with favorable stability and efficiencyproperties for computing general plane curve evolutions is presented. The methodis based on the flowing finite volume discretization of the intrinsic partial differentialequation for updating the position vector of evolving family of plane curves. A curvecan be evolved in the normal direction by a combination of fourth order terms relatedto the intrinsic Laplacian of the curvature, second order terms related to the curva-ture, first order terms related to anisotropy and by a given external velocity field. Theevolution is numerically stabilized by an asymptotically uniform tangential redistri-bution of grid points yielding the first order intrinsic advective terms in the governingsystem of equations. By using a semi-implicit in time discretization it can be numer-ically approximated by a solution to linear penta-diagonal systems of equations (inpresence of the fourth order terms) or tri-diagonal systems (in the case of the secondorder terms). Various numerical experiments of plane curve evolutions, including, inparticular, nonlinear, anisotropic and regularized backward curvature flows, surfacediffusion and Willmore flows, are presented and discussed.

关键词： Geometric partial differential equations evolving plane curves mean curvature flow anisotropy Willmore flow surface diffusion finite volume method semi-implicit scheme tangen-tial redistribution

Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAmI m.EFTEKHARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

关键词：

Neurogenesis dynamics in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： moawiah m.Naffaa Department of Psychology and Neuroscience Duke UniversityDurhamNCUSA Department of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased

关键词： network adaptability neurogenesis neuronal communication olfactory bulb olfactory learning olfactory memory synaptic plasticity

mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第3期20卷 805-807页

作者： Josém.Izquierdo Centro de Biología molecular Severo Ochoa(CBm) Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... 详细信息

关键词： Latin potential lasting

Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2025年第1期46卷 177-192页

作者： m.NAVEED m.ImRAN T.ASGHAR Z.ABBAS Department of mathematics Division of Science and TechnologyUniversity of Education Department of mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAm).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词：

Brain-penetrating neurotrophic factor mimetics: HER-096 as a disease-modifying therapy for Parkinson’s disease

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1094-1095页

作者： Natalia Kulesskaya Kira m.Holmström Henri J.Huttunen Herantis Pharma Plc EspooFinland

Neurotrophic factors as a therapeutic approach in neurodegenerative diseases:A major unmet need in the field of central nervous system diseases is disease-modifying *** for decades there have been various symptomatic treatments available to alleviate the symptoms of the disease,disease-modification,*** that stop,significantly delay,or reverse the progression of the disease,has been turned out to a difficult goal to achieve.

关键词： diseases treatment therapeutic

Arctic sea-ice extent: No record minimum in 2023 or recent years

在线全文

学校读者我要写书评

暂无评论

Atmospheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola m.Johannessen Tor I.Olaussen Nansen Scientific Society BergenNorway Nansen Environmental and Remote Sensing Center BergenNorway

Arctic sea-ice extent reaches its minimum each year in September. On 11 September 2023 the minimum was 4.969 million square kilometers(***^(2)). This was not a record low, which occurred in 2012, when the minimum was 4.175 ***^(2), 0.794 ***^(2) less than the minimum in 2023. However, the ice extent had decreased by 0.432 ***^(2) compared with 2022. Nevertheless, the summer melting in 2023 was remarkably less than expected when considering the strong heat waves in the atmosphere and ocean, with record temperatures set around the world. In general, there is a high correlation between the long-term decrease in sea-ice extent and the increasing CO_(2) in the atmosphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in September, while the remainder is caused by natural variability.

关键词： Sea ice Arctic minimum ice Climate

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2025年第1期46卷 193-208页

作者： K.mUHAmmAD m.SARFRAZ Department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Department of mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(mHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in mATHEmATICA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

关键词：