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electronic,optical,and mechanical properties of bN,AlN,and InN with zinc-blende structure under pressure

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Chinese Physics b 2017年第8期26卷 320-327页

作者： A r Degheidy e b elkenany Department of Physics Faculty of ScienceMansoura UniversityP.O.Box 35516MansouraEgypt

In this work, the electronic, optical, and mechanical properties of bN, AlN, and InN under the action of pressure are calculated. For each of these compounds, the energy band structure, band gaps（e^L_g, e~Γ_g, e^X_g）, refractive index（n）,dielectric constants（ε_∞, ε_0）, elastic constants（C_11, C_12, C_44）, and relevant parameters such as bulk（b_u）, shear（S_h）, and Young＇s（Y_0） moduli are studied, and other important parameters such as bond-stretching（α）, bond-bending（β） force constant, internal-strain parameter（ζ）, effective charges（e~＊_T, Z~＊）, anisotropy factor（I_s）, Poisson＇s ratio（P_o）, Cauchy ratio（C_a）, the ductility index（μ_D）, and linear compressibility（C0_） are also calculated. The effects of pressure on all studied properties are investigated. Our results are in good agreement with the available experimental and theoretical data for bN,AlN, and InN.

关键词： electronic properties optical properties mechanical properties bN A1N InN

Mechanical properties of Ga_xIn_(1-x)As_yP_(1-y)/GaAs system at different temperatures and pressures

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Chinese Physics b 2015年第9期24卷 313-318页

作者： A.r.Degheidy e.b.elkenany Department of Physics Faculty of ScienceMansoura University

The mechanical properties, such as the elastic constants C11, C12, C44, and bulk, Young＇s, and shear moduli, of a Ga x In1-x As y P1-y alloy lattice matching to a Ga As substrate are calculated for various As concentrations. The calculations are based on the pseudo-potential method within the virtual crystal approximation containing the effective disorder potential. The variations of the studied properties with pressure and temperature are investigated. A comparison between the calculated results and the available published data for binary parent compounds shows that they have good agreement,while the calculated results for the quaternary alloys at various temperature and pressure may be taken as a reference.

关键词： elastic constants temperature and pressure electronic band gaps

The response of temperature and hydrostatic pressure of zinc-blende Ga_xIn_(1-x)As semiconducting alloys

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Chinese Physics b 2012年第12期21卷 327-334页

作者： A.r.Degheidy e.b.elkenany Department of Physics Faculty of ScienceMansoura University

The electronic band structure of GaxIn1-xAs alloy is calculated by using the local empirical pseudo-potential method including the effective disorder potential in the virtual crystal approximation. The compositional effect of the electronic energy band structure of this alloy is studied with composition x ranging from 0 to 1. Various physical quantities such as band gaps, bowing parameters, refractive indices, and high frequency dielectric constants of the considered alloys with different Ga concentrations are calculated. The effects of both temperature and hydrostatic pressure on the calculated quantities are studied. The obtained results are found to be in good agreement with the available experimental and published data.

关键词： temperature hydrostatic pressure to GaxIn1-xAs alloys

Neuroinflammation revisited through the microglial lens

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Neural regeneration research 2025年第7期20卷 1989-1990页

作者： renato Socodato João b.relvas Institute of research and Innovation in Health(i3S)and Institute for Molecular and Cell biology(IbMC) University of PortoPortoPortugal Department of biomedicine Faculty of Medicine of the University of Porto(FMUP)PortoPortugal

Neuroimmunology is emerging as a pivotal field,shedding light on the intricate dialogues between the central nervous system(CNS)and the immune *** exploration is particularly significant in understanding microglia,the CNS’s innate immune cells,beyond the conventional conflation of“neuroinflammation”and“microglial activation.”This conflation has clouded the true complexity of these processes,potentially stalling scientific progress and the development of new *** challenge the long-standing perspectives that have oversimplified these interactions,advocating for a deeper exploration of the dynamic relationship between neuroinflammation and microglial *** dissecting specific molecular pathways,we aim to illuminate their elaborate roles in neuroinflammatory responses,especially in the context of Alzheimer’s disease(AD).Here,neuroinflammation is not merely a passive observer or a direct antagonist but a complex agent in the disease’s *** article calls for a significant paradigm shift towards an integrative,multi-omics approach to *** such a comprehensive framework is crucial for advancing our understanding of neuroinflammatory conditions and paving the way for targeted therapeutic strategies for brain diseases.

关键词： inflammation simplified activation

Novel therapeutic strategies targeting mitochondria as a gateway in neurodegeneration

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Neural regeneration research 2023年第5期18卷 991-995页

作者： Diogo Trigo Jose Joao Vitoria Odete A.b.da Cruz e Silva Neuroscience and Signalling Laboratory Institute of Biomedicine(iBiMED)Department of Medical SciencesUniversity of AveiroAveiroPortugal

In recent years, multiple disciplines have focused on mitochondrial biology and contributed to understanding its relevance towards adult-onset neurodegenerative disorders. These are complex dynamic organelles that have a variety of functions in ensuring cellular health and homeostasis. The plethora of mitochondrial functionalities confers them an intrinsic susceptibility to internal and external stressors(such as mutation accumulation or environmental toxins), particularly so in long-lived postmitotic cells such as neurons. Thus, it is reasonable to postulate an involvement of mitochondria in aging-associated neurological disorders, notably neurodegenerative pathologies including Alzheimer’s disease and Parkinson’s disease. On the other hand, biological effects resulting from neurodegeneration can in turn affect mitochondrial health and function, promoting a feedback loop further contributing to the progression of neuronal dysfunction and cellular death. This review examines state-of-the-art knowledge, focus on current research exploring mitochondrial health as a contributing factor to neuroregeneration, and the development of therapeutic approaches aimed at restoring mitochondrial homeostasis in a pathological setting.

关键词： Alzheimer’s disease axon energy homeostasis glymphatic system mitochondria mitostasis neurodegeneration neuroregeneration Parkinson’s disease therapeutical strategies

bio-economic Strategy to Combat Non-Point Pollution in China

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Pedosphere 2005年第2期15卷 156-163页

作者： b. daVIDSON r.e.WHITe Institute of Land and Food resources Institute of Land and Food Resources The University of MelbourneParkville Victoria 3010 (Australia)The University of MelbourneParkville Victoria 3010 (Australia)

While non-point pollution from agriculture has become an increasingly serious problem in China, some progress has been made in studying the causal biophysical processes. However, few studies have assessed the economic consequences of non-point pollution in China or the policy options that could be employed to combat it. In this work a sustainable strategy to control non-point pollution from crop production, which involved taxing excessive inputs of irrigation water and fertilizer, was proposed. The approach taken to assess these measures combined biophysical and economic models,having a trade-off between economic returns and an improved environment. A proven and practical spatially referenced water and nutrient management model was used to determine the quantities of excessive irrigation water and fertilizer for specific soil and land use. Also, a set of indicators were proposed for evaluating the effects of agricultural economic output and agricultural practices on the environment.

关键词： crop production integrated biophysical-economic model non-point pollution policy instrument sustainable strategy

On q-n-gonal Klein Surfaces

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Acta Mathematica Sinica,english Series 2007年第10期23卷 1833-1844页

作者： b.eSTrAda r.A.HIdaLGO e.MArTINeZ Departamento de Matemáticas Funda.entales UNEDPaseo Senda del Rey 928040 MadridSpain Departamento de Matemática Universidad Técnica Federico Santa MaríaCasilla 110-V ValparaisoChile

We consider proper Klein surfaces X of algebraic genus p ≥ 2, having an automorphism φ of prime order n with quotient space X/（φ） of algebraic genus q. These Klein surfaces axe called q-n-gonal surfaces and they are n-sheeted covers of surfaces of algebraic genus q. In this paper we extend the results of the already studied cases n ≤ 3 to this more general situation. Given p ≥ 2, we obtain, for each prime n, the （admissible） values q for which there exists a q-n-gonal surface of algebraic genus p. Furthermore, for each p and for each admissible q, it is possible to check all topological types of q-n-gonal surfaces with algebraic genus p. Several examples are given： q-pentagonal surfaces and q-n-gonal bordered surfaces with topological genus g = 0, 1.

关键词： Klein surfaces riemann surfaces automorphism groups non-euclidean crystallographic groups

LTT switch unit for capacitive energy storages

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Defence Technology（防务技术） 2018年第5期14卷 616-621页

作者： N.e.Nechaev b.e.Fridman A.A.Khapugin V.A.Martynenko r.A.Serebrov D.V.efremov Scientific research Institute of electrophysical Apparatus Saint Petersburg196641Russia electrovipryamitel Saransk430001Russia

When the capacitor cell is discharged in the short-circuit mode, the current pulse amplitude and duration are maximal. Therefore, this mode is the most severe for discharge switches of capacitive energy storage. The characteristics of the transient process of the discharge capacitive energy storage and the current loads acting in the facility discharge circuit have been defined for this mode. The test bench for definition of the LTT(Light Triggered Thyristors) loading capacity is described. The limiting characteristics have been experimentally obtained for LTT, at which there emerges the thermo-generation *** process of OFF-ON switching of LTTs has been investigated, the necessity is shown to use the speedup r-C circuits to ensure fast and stable transition of LTT into the conducting state. The design of the switch unit for the capacitive energy storage comprising LTTs and crowbar diodes is described, and the transient processes of current switching in crowbar diodes are considered. The tests carried out during switching of pul se current up to 100 kA at a voltage of 6 kV have confirmed the workability of the switch unit.

关键词： energy storage Power semiconductor switches Photothyristors Pulse power systems

All-electron ZOrA triple zeta basis sets for the elements Cs-La and Hf-rn

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Chinese Physics b 2023年第9期32卷 242-249页

作者： Antônio Canal Neto Francisco e.Jorge Henrique r.Cda Cruz Departamento de Física Universidade Federal do Espírito Santo29075-910 VitóriaESBrazil

Segmented all-electron basis set of triple zeta valence quality plus polarization functions(TZP)for the elements of the fifth row to be used together with the zero-order regular approximation(ZOrA)is carefully *** correctly describe electrons distant from atomic nuclei,the basis set is augmented with diffuse functions giving rise to a set designated as *** the ZOrA-b3LYP theoretical level,these sets are used to calculate the ionization energy and mean dipole polarizability of some atoms,bond length,dissociation energy,and harmonic vibrational frequency of diatomic ***,these results are compared with the theoretical and experimental data found in the *** considering that our sets are relatively compact,they are sufficiently accurate and reliable to perform property calculations involving simultaneously electrons from the inner shell and outer *** performances of the ZOrA and second-order Douglas-Kroll-Hess Hamiltonians are evaluated and the results are also discussed.

关键词： TZP-ZOrA and ATZP-ZOrA basis sets ZOrA-b3LYP method Cs-La and Hf-rn elements atomic and molecular properties