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

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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

Coarse to Fine: The Role of Severe Plastic Deformation in Advancing Titanium-Based Medical implants - A Comprehensive Review

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 295-306页

作者： Dragana R Mihajlović Bojan i Međo ivana Lj Cvijović-Alagić Veljko R Djokić Faculty of Technology and Metallurgy University of BelgradeKarnegijeva 411120 BelgradeSerbia Vinča institute of Nuclear Sci-ences-National institute of the Republic of Serbia University of Belgrade11001BeogradSerbia innovation Centre of the Faculty of Technology and Metallurgy Karnegijeva 411120 BelgradeSerbia

This paper describes severe plastic deformation(SPD)procedures,which are utilized to form an ultrafine-grained structure in metallic *** the SPD process,a solid material sample is subjected to very high loads without a significant change in sample *** the present work,the high-pressure torsion(HPT)process,as one of the SPD techniques,which achieves a high degree of deformation and ensures refinement of the microstructure,will be discussed in more *** that grain size control is accepted as a method to obtain materials with desired characteristics,an overview of the properties of ultrafine-grained titanium-based biomaterials to be used in medicine is ***,particular attention is dedicated to the influences of HPT process parameters,primarily hydrostatic pressure,and number of revolutions during torsion,on the grain size and physical and mechanical characteristics(modulus of elasticity,microhardness,and tensile properties),corrosion resistance,and biocompatibility of the titanium-based biomaterials.A review of the literature indicates that titanium-based materials obtained by the SPD process show improved mechanical and physical properties without losing biocompatibility and corrosion resistance,which suggests that these methods of obtaining implants are something that should be further developed in the future.

关键词： high-pressure torsion process ultrafine-grained titanium-based materials electrochemical anodization physical properties mechanical properties

BLOWiNG UP AND MULTiPLiCiTY OF SOLUTiONS FOR A FOURTH-ORDER EQUATiON WiTH CRiTiCAL NONLiNEARiTY

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Acta Mathematica Scientia 2015年第6期35卷 1511-1546页

作者： Siwar AMMAR Mokhles hammami Department of mathematics University of Monastir Department of mathematics Faculty of Sciences of sfax University of Sfax

in this paper, we consider the following nonlinear elliptic problem ： △2u =｜u｜n-4^-u＋u｜u｜q-1u,in Ω,△u=u=0 on ЭΩ,where Ω is a bounded and smooth domain in R^n,n∈{5,6,7},u is a parameter and q∈]4/（n-4）,（12-n）/（n-4）].We study the solutions which concentrate around two points of Ω. We prove that the concentration speeOs are the same order and the distances of the concentration points from each other and from the boundary are bounded. For Ω=（Ωa）a a smooth ringshaped open set, we establish the existence of positive solutions which concentrate at two points of Ω. Finally, we show that for u〉0, large enough, the problem has at least many positive solutions as the Ljusternik-Schnirelman category of Ω.

关键词： fourth order elliptic equations critical Sobolev exponent blow up solution

Robust Output Practical Stability of Time-Varying Nonlinear Control Systems via indefinite Lyapunov Functions

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Journal of Systems Science & Complexity 2024年第6期37卷 2595-2613页

作者： DAMAK Hanen ABOTHHER Amal hammami Mohamed Ali Department of Mathematics University of SfacPreparatory Engineering Institute of SfaxSfax 3047Tunisia Department of Mathematics University of ZawiaFaculty of education Abu EssaZawia 16418Libya Department of Mathematics University of SfacFaculty of Sciences of SfaxSfax 3047Tunisia

This paper focuses on studying the problem of robust output practical stability of timevarying nonlinear control systems. The main innovation lies in the fact that the proposed approach for stability analysis allows for the computation of bounds that characterize the asymptotic convergence of solutions to a small ball centered at the origin using a Lyapunov method with a definite *** different conditions on the perturbation, the authors demonstrate that the system can be globally robustly asymptotically output stable by designing a candidate feedback controller. Finally, three examples are given to illustrate the practical implications and significance of the theoretical results.

关键词： Control theory global robust practical asymptotic output stability(GRPAOS) Lyapunov method time-varying control systems

Multisensory mechanisms of gait and balance in Parkinson’s disease:an integrative review

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Neural Regeneration Research 2025年第1期20卷 82-92页

作者： Stiven Roytman Rebecca Paalanen Giulia Carli Uros Marusic Prabesh Kanel Teus van Laar Nico i.Bohnen Department of Radiology University of MichiganAnn ArborMIUSA Department of Neurology University of MichiganAnn ArborMIUSA Morris K.Udall Center of Excellence for Parkinson’s Disease Research University of MichiganAnn ArborMIUSA institute for Kinesiology Research Science and Research Centre KoperKoperSlovenia Department of Health Sciences Alma Mater Europaea–ECMMariborSlovenia Parkinson’s Foundation Research Center of Excellence University of MichiganAnn ArborMIUSA Department of Neurology University of GroningenUniversity Medical Center GroningenGroningenThe Netherlands Neurology Service and GRECC VA Ann Arbor Healthcare SystemAnn ArborMIUSA

Understanding the neural underpinning of human gait and balance is one of the most pertinent challenges for 21st-century translational neuroscience due to the profound impact that falls and mobility disturbances have on our aging *** and gait control does not happen automatically,as previously believed,but rather requires continuous involvement of central nervous *** effectively exert control over the body,the brain must integrate multiple streams of sensory information,including visual,vestibular,and somatosensory *** mechanisms which underpin the integration of these multisensory signals are the principal topic of the present *** multisensory integration theories focus on how failure of cognitive processes thought to be involved in multisensory integration leads to falls in older *** emphasis,however,has been placed on specific contributions of individual sensory modalities to multisensory integration processes and cross-modal interactions that occur between the sensory modalities in relation to gait and *** the present work,we review the contributions of somatosensory,visual,and vestibular modalities,along with their multisensory intersections to gait and balance in older adults and patients with Parkinson’s *** also review evidence of vestibular contributions to multisensory temporal binding windows,previously shown to be highly pertinent to fall risk in older ***,we relate multisensory vestibular mechanisms to potential neural substrates,both at the level of neurobiology(concerning positron emission tomography imaging)and at the level of electrophysiology(concerning electroencephalography).We hope that this integrative review,drawing influence across multiple subdisciplines of neuroscience,paves the way for novel research directions and therapeutic neuromodulatory approaches,to improve the lives of older adults and patients with neurodegenerative diseases.

关键词： aging balance encephalography functional magnetic resonance imaging gait multisensory integration Parkinson’s disease positron emission tomography somatosensory vestibular visual

Apolipoprotein A-i binding protein-mediated neuroprotection in glaucomatous neuroinflammation and neurodegeneration

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Neural Regeneration Research 2025年第5期20卷 1414-1415页

作者： Sinwoo Hwang Seunghwan Choi Soo-Ho Choi Keun-Young Kim Yury i.Miller Won-Kyu Ju Hamilton Glaucoma Center and Shiley Eye institute The Viterbi Family Department of OphthalmologyUniversity of California San DiegoLa JollaCAUSA Department of Medicine University of California San DiegoLa JollaCAUSA National Center for Microscopy and imaging Research Department of NeurosciencesUniversity of California San DiegoLa JollaCAUSA

Glaucoma is a multifactorial eye disorder that can cause vision loss and irreversible blindness,affecting individ uals aged 40 to 80 yea rs *** to the aging population,it is expected that the number of people affected by glaucoma will surpass 111 million by 2040 as the disease becomes more *** primarily contributes to optic nerve axon loss and the progressive degeneration of retinal ganglion cells (RGCs),subsequently leading to vision impairment.

关键词： irreversible pass primarily

Practical stabilization of a class of uncertain time-varying nonlinear delay systems

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控制理论与应用（英文版） 2009年第2期7卷 175-180页

作者： Bassem Ben HAMED Mohamed Ali hammami institut Supérieur des Sciences Appliquées et de Technologie de Gabès Département de MathématiquesRue Amor Ben El Khatab 6029 GabèsTunisia Faculté des Sciences de Sfax Département de Mathématiques BP 802 Route Soukra km 4 Sfax 3018Tunisia

in this paper we deal with a class of uncertain time-varying nonlinear systems with a state delay. Under some assumptions, we construct some stabilizing continuous feedback, i.e. linear and nonlinear in the state, which can guarantee global uniform exponential stability and global uniform practical convergence of the considered system. The quadratic Lyapunov function for the nominal stable system is used as a Lyapunov candidate function for the global system. The results developed in this note are applicable to a class of dynamical systems with uncertain time-delay. Our result is illustrated by a numerical example.

关键词： Nonlinear system Time-delay Feedbacks Practical convergence Lyapunov function

Numerical investigation of low relative humidity aeration impact on the moisture content of stored wheat

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international Journal of Modeling, Simulation, and Scientific Computing 2017年第2期8卷 39-54页

作者： Faten hammami Salah Ben Mabrouk Abdelkhader Mami Laboratory of Energy and Thermal Processes Research and Technology Centre of Energy CRTEn.P.B:95.Hammam-Life 2050Tunisia Laboratory of Analysis Conception and Control Systems Faculty of Sciences of Tunis.Tunis El Manar1002Tunisia

High moisture content wheat kernels are subject to elevated respiration rates due to enzyme activity and mould growth that reduce the dry grain and may produce suffi-cient energy which may be harmful to wheat *** aeration provides a powerful nonchemical stored grain insect ***,aeration is a suitable and economical device to overcome this *** moisture management is vital to prevent spoilage in stored *** objective of this study is to investigate the influence of using low relative humidity(RH)aeration on the wheat moisture *** numerical investigation based on heat and mass balances is developed and used to simulate the evolution of grain temperature and moisture under various air RH in a wheat storage *** show that the dehumidification of blown air had greater potential for decreasing RH of interstitial air and wheat moisture at 30◦C temperature and RH of 40%,50%and 60%.

关键词： Wheat storage moisture content dehumidifier aeration relative humidity simulation.

EXiSTENCE AND STABiLiTY RESULTS FOR GENERALiZED FRACTiONAL DiFFERENTiAL EQUATiONS

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Acta Mathematica Scientia 2020年第1期40卷 141-154页

作者： A.BEN MAKHLOUF D.BOUCENNA M.A.hammami Department of Mathematics College of SciencesJouf UniversityAljoufSaudi Arabia Department of Mathematics Faculty of Sciences of SfaxBP 11713000 SfaxTunisia Higher School for Professors of Technological Education SkikdaAlgeria

in this paper,a sufficient conditions to guarantee the existence and stability of solutions for generalized nonlinear fractional differential equations of orderα(1<α<2)are *** main results are obtained by using Kras... 详细信息

in this paper,a sufficient conditions to guarantee the existence and stability of solutions for generalized nonlinear fractional differential equations of orderα(1in results are obtained by using Krasnoselskii's fixed point theorem in a weighted Banach *** examples are given to demonstrate the validity of the proposed results.

关键词： nonlinear fractional differential equations stability analysis generalized fractional derivative Krasnoselskii's fixed point theorem