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The magnetosheath at high spectral resolution

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Earth and Planetary Physics 2024年第1期8卷 234-246页

作者： K.d.Küntz d.Koutroumpa W.R.dunn A.foster f.S.Porter d.G.Sibeck B.Walsh The Henry A.Rowland department of Physics and Astronomy Johns Hopkins University3701 San Martin DriveBaltimoreMD21218USA NASA Goddard Space flight Center 8800 Greenbelt RoadGreenbeltMD 20771USA LATMOS-OVSQ CNRSUVSQ Paris-SaclaySorbonne Université11 Boulevard d’Alembert78280GuyancourtFrance department of Physics and Astronomy University College LondonLondonUK The Centre for Planetary Science at UCL/Birkbeck Gower StreetLondon WC1E 6BTUK Center for Astrophysics Harvard University&Smithsonian Institution60 Garden StreetCambridgeMA 02138USA Center for Space Physics Boston University110 Cummington MallBostonMAUSA

While we eagerly anticipate SMILE’s(Solar wind Magnetosphere Ionosphere Link Explorer)unprecedented X-ray observations of the Earth’s magnetosheath and the initiation of a new era of magnetospheric research,it seems appropriate to look ahead to the abilities of the next generation of astrophysics *** these,the Line Emission Mapper(LEM),a large aperture micro-calorimeter based mission,is currently planned to be able to observe the magnetosheath at high spectral resolution(~2 eV).With a field of view of~30′,LEM will allow higher spatial resolution and higher cadence measurement of the motion of a very small portion of the magnetopause over relatively short periods of time(multiple hours),complementing SMILE’s global ***’s strength is its spectral *** will be able to measure the abundance of a broad range of elements and ionization states,many of which are inaccessible to current in situ instruments,and will be able to separate the emission from the magnetosheath from the emission from the cosmic X-ray background using the difference in their relative velocities.

关键词： magnetosheath charge exchange solar wind abundances

Intestinal glucagon-like peptide-1:A new player associated with impaired counterregulatory responses to hypoglycaemia in type 1 diabetic mice

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World Journal of diabetes 2024年第8期15卷 1764-1777页

作者： fang-Xin Jin Yan Wang Min-ne Li Ru-Jiang Li Jun-Tang Guo department of Histology and Embryology Key Laboratory of Universities in Shandong ProvinceShandong Second Medical UniversityWeifang 261053Shandong ProvinceChina department of Pathological Physiology Shandong Second Medical UniversityWeifang 261053Shandong ProvinceChina

BACKGROUNd Impaired hypoglycaemic counterregulation has emerged as a critical concern for diabetic patients who may be hesitant to medically lower their blood glucose levels due to the fear of potential hypoglycaemic ***,the pathogenesis of hypoglycaemic counterregulation is still ***-like peptide-1(GLP-1)and its analogues have been used as adjunctive therapies for type 1 diabetes mellitus(T1dM).The role of GLP-1 in counterregulatory dysfunction during hypoglycaemia in patients with T1dM has not been *** To explore the impact of intestinal GLP-1 on impaired hypoglycaemic counterregulation in type 1 diabetic *** T1dM was induced in C57BL/6J mice using streptozotocin,followed by intraperitoneal insulin injections to create T1dM models with either a single episode of hypoglycaemia or recurrent episodes of hypoglycaemia(dH5).Immunofluorescence,Western blot,and enzyme-linked immunosorbent assay were employed to evaluate the influence of intestinal GLP-1 on the sympathetic-adrenal reflex and glucagon(GCG)*** GLP-1 receptor agonist GLP-1(7-36)or the antagonist exendin(9-39)were infused into the terminal ileum or injected intraperitoneally to further investigate the role of intestinal GLP-1 in hypoglycaemic counterregulation in the model *** The expression levels of intestinal GLP-1 and its receptor(GLP-1R)were significantly increased in dH5 *** instances of excess of intestinal GLP-1 weakens the sympathetic-adrenal reflex,leading to dysfunction of adrenal counterregulation during ***5 mice showed increased pancreaticδ-cell mass,cAMP levels inδcells,and plasma somatostatin concentrations,while cAMP levels in pancreaticαcells and plasma GCG levels ***,GLP-1R expression in islet cells and plasma active GLP-1 levels were significantly increased in the dH5 *** experiments involving terminal ileal infusion and intraperitoneal injection in the model mice demonstra

关键词： Glucagon-like peptide-1 Impaired hypoglycaemic counterregulation Type 1 diabetes Intestine Pancreas

Crosstalk between androgen signaling and the chemokine receptor CXCR4:a novel strategy to promote myelin regeneration

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neural Regeneration Research 2025年第9期20卷 2581-2582页

作者： Marianne Bardy-Lagarde Narimène Asbelaoui Abdel Mouman Ghoumari UMR1195 “Diseases and Hormones of the Nervous System”Inserm and University Paris-SaclayKremlin-BicêtreFrance

Multiple sclerosis(MS)is the most common chronic disease of the central nervous system(CNS)in young adults and represents the first cause of severe handicap,originally non-traumatic(Oh et al.,2018).MS is chara cterized by the infiltration of auto reactive lymphocytes specific to myelin through the blood-brain barrier,which results in the appearance of inflammatory demyelinating lesions caused by the death of the central nervous system myelinating cells,oligodendrocytes(Oh et al.,2018).There is a prevalence sexual with a ratio of three times more affected women than men.

关键词： myelin CXCR4

Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates

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Journal of Semiconductors 2024年第9期45卷 28-35页

作者： Leonarde N.Rodrigues Wesley f.Inoch Marcos L.f.Gomes Odilon d.d.Couto Jr. Bráulio S.Archanjo Sukarno O.ferreira Physics department Federal University of ViçosaViçosa36570-900Minas GeraisBrazil Instituto de física Gleb Wataghin Universidade Estadual de CampinasCampinas13083-859São PauloBrazil National Institute of Metrology Quality and Technology(Inmetro) Materials Metrology Division(DIMAT)Xerém2525-020Rio de JaneiroBrazil

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2d character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0d) 0d nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

关键词： CdMnTe/CdTe/CdMnTe heterostructure CdTe/CdMnTe quantum emitters quantum dot-like emission silicon(111)substrate

Two-Stream Approximation to the Radiative Transfer Equation:A new Improvement and Comparative Accuracy with Existing Methods

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Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： f.Momo TEMGOUA L.Akana NGUIMdO dNJOMO Environmental Energy Technologies Laboratory(EETL) Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon department of Electrical and Electronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical modeling of the interaction between solar radiation and the Earth's atmosphere is formalized by the radiative transfer equation(RTE), whose resolution calls for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the development of the phase function and the intensity into a third-order series of Legendre polynomials. This new approach, which adds one more term in the expression of the intensity and the phase function, allows in the conditions of a plane parallel atmosphere a new mathematical formulation of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined delta function and Modified Eddington, and second-order approximation methods with reference to the discrete Ordinate(disort) method(δ –128 streams), considered as the most precise. This work also determines the conversion function of the proposed new Method using the fundamental definition of two-stream approximation(f-TSA) developed in a previous work. Notably,new Method has generally better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, new Method shows very good precision for wide domains of the zenith angle μ 0, but tends to deviate from the disort method with the zenith angle, especially for high values of optical thickness. In spite of this divergence in reflectance for high values of optical thickness, very strong correlation with the disort method(R ≈ 1) was obtained for most cases of optical thickness in this study. An analysis of the Legendre polynomial series for simple functions shows that the high precision is due to the fact that the approximated functions ameliorate the accuracy when the order of approximation increases, although it has been proven that there is a limit order depending on the function from which the precision is lost. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method Legendre polynomial optical thickness moments of specific intensity conversion function transmittance reflectance

The Life and Political Leadership of Gra?a Machel

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心理传记与质性心理学

心理传记与质性心理学 2024年第1期 126-154页

作者： Claude-Hélène Mayer University of Johannesburg South Africa

This article focuses on the life and political leadership of an extraordinary woman leader, Gra?a Machel. Gra?a Machel was born in very poor circumstances in rural Mozambique, became a fighter against colonialism, and married to Presidents: firstly, she married Samora Machel, later she married nelson Mandela. At the same time, she followed her own political career, always promoting a political agenda of education, peace and distribution of wealth. Her political leadership is an extraordinary example for leaders in Southern Africa and the world. This psychobiography contributes to expanding the psychobiographies on extraordinary women in political leadership in Southern Africa. Its aim is to present new insights into the life of Gra?a Machel and her political leadership as a woman leader in pan-African contexts from a psychobio-graphical perspective.

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Effects of Prandtl and Jacob Numbers and dimensionless Thermal Conductivity on Velocity Profiles in Media (Porous and Liquid)

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Journal of Modern Physics 2024年第10期15卷 1603-1614页

作者： Momath Ndiaye Madialène Sene Goumbo Ndiaye department of Hydraulics Rural Engineering Machinery and Renewable Energy UFR Fundamental and Engineering Sciences University of Sine Saloum El Hadj Ibrahima NIASS Kaolack Senegal

In this present study, we analyzed the effects of Prandtl and Jacob numbers and dimensionless thermal conductivity on the velocity profiles in media (porous and liquid). The transfers in the porous medium and the liquid film are described respectively by the improved Wooding model and the classical boundary layer equations. The mesh of the digital domain is considered uniform in the transverse and longitudinal directions. The advection and diffusion terms are discretized with a back-centered and centered scheme respectively. The coupled systems of algebraic equations thus obtained are solved numerically using an iterative line-by-line relaxation method of the Gauss-Seidel type. The results show that the parameters relating to the thermal problem (the dimensionless thermal conductivity, the Prandtl (Pr) and Jacob (Ja) numbers) have no influence on the dimensionless speed, although the thermal and hydrodynamic problems are coupled. Via the heat balance equation. The results obtained show that the parameters relating to the thermal problem have no influence on the dimensionless speed, although the thermal and hydrodynamic problems are coupled via the heat balance equation. So, at first approximation with the chosen constants, we can solve the hydrodynamic problem independently of the thermal problem.

关键词： Condensation Implicit finite difference Thin film Porous Material Model Wooding Vertical Wall

Numerical analysis of high‑speed railway slab tracks using calibrated and validated 3d time‑domain modelling

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Railway Engineering Science 2024年第1期32卷 36-58页

作者： A.f.Esen O.Laghrouche P.K.Woodward d.Medina‑Pineda Q.Corbisez J.Y.Shih d.P.Connolly Institute for High‑Speed Rail and System Integration University of LeedsLeeds LS29JTUK Institute for Infrastructure and Environment Heriot-Watt UniversityEdinburgh EH144ASUK Alstom Transport Saint‑OuenFrance Birmingham Centre for Railway Research and Education University of BirminghamBirmingham B152TTUK

Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance *** this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in *** is then compared to the performance of a ballasted ***,slab and ballasted track models are developed to replicate the full-scale testing of track *** the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track *** slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the *** travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical *** train loading methods are discussed,and the most practical approach is retained and ***,correlations are made between the geotechnical parameters of modern high-speed rail and conventional *** is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds.

关键词： High-speed railways Slab track new ballastless track Ballasted track Critical speeds finite element modelling Calibration of numerical models

Control and vibration analyses of a sandwich doubly curved micro-composite shell with honeycomb,truss,and corrugated cores based on the fourth-order shear deformation theory

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Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1773-1790页

作者： f.SHIRdELAN M.MOHAMMAdIMEHR f.BARGOZINI department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashan 87317-53153Iran

Curved shells are increasingly utilized in applied engineering due to their shared characteristics with other sandwich structures,flexibility,and attractive ***,the inability of controlling and regulating vibrations and destroying them afterward is a challenge to *** this paper,the curve shell equations and a linear quadratic regulator are adopted for the state feedback design to manage the structure vibrations in state space forms.A five-layer sandwich doubly curved micro-composite shell,comprising two piezoelectric layers for the sensor and actuator,is modeled by the fourth-order shear deformation *** core(honeycomb,truss,and corrugated)is analyzed for the bearing of transverse shear *** results show that the honeycomb core has a greater effect on the *** the parameters related to the core and the weight percentage of graphene increase,the frequency *** uniform distribution of graphene platelets results in the lowest natural frequency while the natural frequency ***,without taking into account the piezoelectric layers,the third-order shear deformation theory(TSdT)and fourth-order shear deformation theory(fOSdT)align ***,when the piezoelectric layers are incorporated,these two theories diverge significantly,with the frequencies in the fOSdT being lower than those in the TSdT.

关键词： vibration and control doubly curved shell micro-composite honeycomb truss corrugate core