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Mechanical Properties of Collagen Biomimetic Films Formed in the Presence of Calcium,Silica and Chitosan

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Journal of Bionic Engineering 2008年第2期5卷 149-158页

作者： mihai Chirita Medical Bioengineering Faculty Medicine and Pharmacy University "Gr.T.Popa"Iasi 7000115Romania

Using eucollagen solutions from ox hide, we cast collagen films to assess the influence of calcium and silica on the reconstitution of the fibrous structure of collagen. The tensile strength and the breaking elongation of the reconstituted collagen films were measured and analysed. Significant differences were observed between reconstituted collagen films with and without calcium and silica. The breaking elongation of the films obtained in the presence of silica was significantly greater, and the degradation was lower than other films of reconstituted collagen. Collagen and chitosan do not exist together as blends in nature, but the specific properties of each may be used to produce in biomimetic way man-made blends with biomedical applications, that confer unique structural, mechanical （detail） and in vivo properties.

关键词： modified collagen biomimetic films chitosan biomaterials biopolymers mechanical properties

Weak Solutions for the Vlasov-Poisson Initial-Boundary Value Problem with Bounded Electric Field

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Chinese Annals of Mathematics,Series B 2007年第4期28卷 389-420页

作者： mihai BOSTAN Laboratoire de Mathématiques Université de Franche-Comté 16 route de Gray F-25030 BesanconFance.

The aim of this work is to construct weak solutions for the three dimensional Vlasov-Poisson initial-boundary value problem with bounded electric field. The main in-gredient consists of estimating the change in momentum along characteristics of regular electric fields inside bounded spatial domains. As direct consequences, the propagation of the momentum moments and the existence of weak solution satisfying the balance of total energy are obtained.

关键词： Vlasov-Poisson equations Vlasov-Maxwell equations Weak solutions

Automatic landing system using neural networks and radio-technical subsystems

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Chinese Journal of Aeronautics 2017年第1期30卷 399-411页

作者： Romulus Lungu mihai Lungu University of Craiova Faculty of Electrical Engineering

The paper focuses on the design of a new automatic landing system（ALS） in longitudinal plane; the new ALS controls the aircraft trajectory and longitudinal velocity. Aircraft control is achieved by means of a proportional-integral（PI） controller and the instrumental landing system– the first phase of landing（the glide slope） and a proportional-integral-derivative（PID） controller together with a radio-altimeter – the second phase of landing（the flare）; both controllers modify the reference model associated with aircraft pitch angle. The control of the pitch angle and longitudinal velocity is performed by a neural network adaptive control system, based on the dynamic inversion concept, having the following as components： a linear dynamic compensator, a linear observer, reference models, and a Pseudo control hedging（PCH） block. The theoretical results are software implemented and validated by complex numerical simulations; compared with other ALSs having the same radio-technical subsystems but with conventional or fuzzy controllers for the control of aircraft pitch angle and longitudinal velocity, the architecture designed in this paper is characterized by much smaller overshoots and stationary errors.

关键词： Adaptive control Automatic landing Neural network PID Reference model

Review of the bennettitalean genus Weltrichia

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Journal of Palaeogeography 2019年第2期8卷 109-129页

作者： mihai Emilian Popa Faculty of Geology and Geophysics Department of Geology and Doctoral School of GeologyLaboratory of PalaeontologyUniversity of Bucharest

The bennettitalean male reproductive structure Weltrichia Braun 1849 *** 1969(Family Williamsoniaceae) is discussed from several points of view,including anatomy and morphology,species diversity and validity,phytogeographical and stratigraphical distribution,and reproduction strategy.A very rare fossil,genus Weltrichia includes 25 valid species distributed in both hemispheres during Triassic and Jurassic *** contribution critically reviews the systematics of the entire genus,together with its stratigraphical and palaeophytogeographical significance.

关键词： Bennettitales Weltrichia Male reproductive structure Triassic Jurassic

Reissner-Nordstrom-de-Sitter-type Solution by a Gauge Theory of Gravity

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Chinese Physics Letters 2008年第10期25卷 3570-3573页

作者： V. Enache Camelia Popa V. paun M. Agop Department of Theoretical Physics Faculty of Physics Al.I.Cuza University Blvd. Carol No.l 700506 Iasi Romania Department of Physics Faculty of Applied Sciences Politehnica University of Bucharest I 313 Splaiul lndependentei Street 060042 Bucharest Romania Department of Physics Gh. Asachi Technical University Blvd. Mangeron 700029 Iasi Romania Department of Physics University of Athens Athens 15771 Greece

We use the theory based on a gravitational gauge group （Wu＇s model） to obtain a spherical symmetric solution of the field equations for the gravitational potential on a Minkowski spacetime. The gauge group, the gauge covariant derivative, the strength tensor of the gauge feld, the gauge invariant Lagrangean with the cosmological constant, the field equations of the gauge potentiaIs with a gravitational energy-momentum tensor as well as with a tensor of the field of a point like source are determined. Finally, a Reissner-Nordstrom-de Sitter-type metric on the gauge group space is obtained.

关键词： WEYL-DIRAC THEORY GRAVITATIONAL-FIELD EQUATIONS INVARIANCE DUALITY gravitational fields DUALITY Gravity Tensor FIELD EQUATIONS gauge theory invariance

New results on Cll and C12 lattices with applications to Grothendieck categories and torsion theories

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Frontiers of Mathematics in China 2016年第4期11卷 815-828页

作者： Toma ALBU mihai IOSIF Simion Stoilow Institute of Mathematics of the Romanian Academy Research Unit 5 P.O. Box 1-764 RO-010145 Bucharest 1 Romania Bucharest University Department of Mathematics Academiei Str. 14RO-010014 Bucharest 1 Romania

In this paper, which is a continuation of our previous paper [T. Albu, M. Iosif, A. Tercan, The conditions （Ci） in modular lattices, and applications, J. Algebra Appl. 15 （2016）, http： ***/10.1142/S0219498816500018], we investigate the latticial counterparts of some results about modules satisfying the conditions （Cll） or （C12）. Applications are given to Grothendieck categories and module categories equipped with hereditary torsion theories.

关键词： Modular complement lattice C12 theory element lattice upper closed element lattice Goldie dimension continuous lattice essential element uniform lattice condition (Ci) Cll socle Grothendieck category torsion

Genus Pronephrium Presl 1851 (Thelypteridaceae) in Romania

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Journal of Palaeogeography 2018年第4期7卷 295-307页

作者： Roxana Pirnea mihai Emilian Popa faculty of geology and geophysics doctoral school of geology university of bucharest 1 N. Ealcescu Ave 010041 BucharestRomania faculty of geology and geophysics department of geology laboratory of palaeontology university of bucharest 1 N. Ealcescu Ave 010041 BucharestRomania

Pronephrium stiriacum（Unger） Knobloch et Kvatek 1976（Filicales, Thelypteridaceae Holttum 1971） is reported from the Oligocene Petrosani Basin and from the Miocene Bozovici Basin in Romania. Morphological variations of this species, such as size of the leaves, venation and marginal teeth, in the Oligocene-Miocene time interval in Romania are described, discussed and illustrated. The distribution of the Thelypteridacean species Pronephrium stiriacum is also discussed regarding its European expansion during the Cenozoic. Moreover, the palaeoecology of this species is discussed based on taphonomy and occurrences, as Pronephrium stiriacum was a secondary coal generator.

关键词： Thelypteridaceae Pronephrium stiriacum Oligocene Miocene Romania

Physical aspects of f(R,G_(μν)T^(μν))modified gravity theories

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Chinese Physics C 2023年第10期47卷 237-248页

作者： mihai Marciu Dana Maria Ioan Faculty of Physics University of Bucharest405 AtomistilorPOB MG-11RO-077125Bucharest-MagureleRomania

The paper extends basic Einstein–Hilbert action by incorporating an invariant derived from a specific contraction between the Einstein tensor and energy momentum *** represents a non–minimal coupling between the space–time geometry and matter *** fundamental Einstein–Hilbert action is extended by considering a generic function f(R,GμνTμν).This function is subsequently dissected into its primary components:a geometric part reliant on the scalar curvature,and another segment encapsulating the interaction between geometry and matter *** cosmological models are formulated at the backdrop of these dynamics,rooted in specific associations between the matter energy-momentum tensor and Einstein *** deriving the consequent field equations,the cosmological model's physical implications are explored through a dynamical system analysis applied to diverse coupling *** exploration reveals that the current model aligns with various phases in the Universe's evolution,potentially elucidating several late-time historical epochs.

关键词： dark energy cosmology modified gravity theories

Cluster dynamics modeling of niobium and titanium carbide precipitates inα-Fe andγ-Fe

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Chinese Physics B 2022年第2期31卷 509-515页

作者： Nadezda Korepanova Long Gu mihai Dima Hushan Xu Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 101408China Institute for Physics and Nuclear Engineering Bucharest 077125Romania School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China Paul Scherrer Institute Villigen 5232Switzerland

Kinetic behaviors of niobium and titanium carbide precipitates in iron are simulated with cluster *** simulations,carried out in austenite and ferrite for niobium carbides,and in austenite for titanium carbide,are analyzed for dependences on temperature,solute concentration,and initial cluster *** results are presented for different temperatures and solute concentrations,compared to experimental data *** show little impact of initial cluster distribution beyond a certain relaxation time and that highly dilute alloys with monomers only present a significantly different behavior from denser alloys or ones with different initial cluster distributions.

关键词： cluster dynamics precipitates precipitation kinetics carbides