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Journal of Central South University 2015年第8期22卷 3097-3107页

作者：谭鑫 KONIEtZKY H frühwirt t College of Civil Engineering Hunan University Geotechnical Institute TU Bergakademie Freiberg

the understanding of the rock deformation and failure process and the development of appropriate constitutive models are the basis for solving problems in rock engineering. In order to investigate progressive failure behavior in brittle rocks, a modified constitutive model was developed which follows the principles of the continuum damage mechanics method. It incorporates non-linear Hoek-Brown failure criterion, confining pressure-dependent strength degradation and volume dilation laws, and is able to represent the nonlinear degradation and dilation behaviors of brittle rocks in the post-failure region. A series of triaxial compression tests were carried out on Eibenstock(Germany) granite samples. Based on a lab data fitting procedure, a consistent parameter set for the modified constitutive model was deduced and implemented into the numerical code FLAC3 D. the good agreement between numerical and laboratory results indicates that the modified constitutive law is well suited to represent the nonlinear mechanical behavior of brittle rock especially in the post-failure region.

关键词： progress failure strength degradation dilation Hoek-Brown criterion numerical simulation brittle rock

Investigation of creep behaviours of gypsum specimens with flaws under different uniaxial loads

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第1期10卷 151-163页

作者： tina Marolt Cebasek thomas frühwirt Institute for Infrastructure and Environment School of EnergyGeoscienceInfrastructure and SocietyHeriot-Watt UniversityEH14 4ASEdinburghScotlandUK Geotechnical Institute TU Bergakademie FreibergGustav-Zeuner-Str.109599FreibergGermany

the aim of this study is to identify the influence of the dip angle of a pre-existing macrocrack on the lifetime and ultimate deformation of rock-like material. Prediction of lifetime has been studied for three groups of specimens under axial static compressive load levels. the specimens were investigated from 65% to 85% of UCS(uniaxial compressive strength) at an interval of 10% of UCS for the groups of specimens with a single modelled open flaw with a dip angle to the loading direction of 30°(first group), at an interval of 5% of UCS increment for the groups of specimens with single(second group), and double sequential open flaws with a dip angle to the loading direction of 60°(third group). this study shows that crack propagation in specimens with a single flaw follows the same sequences. At first, wing cracks appear, and then shear crack develops from the existing wing cracks. Shear cracking is responsible for specimen failure in all three groups. A slip is expected in specimens from the third group which connects two individual modelled open flaws. the moment of the slip is noticed as a characteristic rise in the axial deformation at a constant load level. It is also observed that axial deformation versus time follows the same pattern, irrespective of local geometry. Specimens from the first group exhibit higher axial deformation under different load levels in comparison with the specimens from the second and third groups.

关键词： Crack propagation Rock-like material Lifetime prediction Static compressive load Macrocrack Wing crack

Additive neurorestorative effects of exercise and docosahexaenoic acid intake in a mouse model of Parkinson’s disease

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Neural Regeneration Research 2025年第2期20卷 574-586页

作者： Olivier Kerdiles Méryl-Farelle Oye Mintsa Mi-mba Katherine Coulombe Cyntia tremblay VincentÉmond Martine Saint-Pierre Clémence Rouxel Line Berthiaume Pierre Julien francesca Cicchetti frédéric Calon Facultéde pharmacie UniversitéLaval1050 Avenue de la MédecineQuebecQCCanada Axe Neuroscience Centre de recherche du CHU de Québec-UniversitéLaval(Pavillon CHUL)2705 Boulevard LaurierQuebecQCCanada Institute of Nutrition and Functional Foods QuebecQCCanada Optinutribrain International Associated Laboratory(NutriNeuro FranceINAFCanada)QuebecQCCanada Axe Endocrinologie et Néphrologie Centre de recherche du CHU de Québec-UniversitéLavalQuebecQCCanada Département de Médecine Facultéde MédecineUniversitéLavalQuebecQCCanada Département de Psychiatrie et Neurosciences Facultéde MédecineQuebecQCCanada

there is a need to develop interventions to slow or reverse the degeneration of dopamine neurons in Parkinson’s disease after *** that preclinical and clinical studies suggest benefits of dietary n-3 polyunsaturated fatty acids,such as docosahexaenoic acid,and exercise in Parkinson’s disease,we investigated whether both could synergistically interact to induce recovery of the dopaminergic ***,mice received a unilateral stereotactic injection of 6-hydroxydopamine into the striatum to establish an animal model of nigrostriatal *** weeks after lesion,animals were fed a docosahexaenoic acid-enriched or a control diet for the next 8 *** this period,the animals had access to a running wheel,which they could use or *** acid treatment,voluntary exercise,or the combination of both had no effect on(i)distance traveled in the open field test,(ii)the percentage of contraversive rotations in the apomorphine-induction test or(iii)the number of tyrosine-hydroxylase-positive cells in the substantia nigra pars ***,the docosahexaenoic acid diet increased the number of tyrosine-hydroxylase-positive terminals and induced a rise in dopamine concentrations in the lesioned *** to docosahexaenoic acid treatment or exercise alone,the combination of docosahexaenoic acid and exercise(i)improved forelimb balance in the stepping test,(ii)decreased the striatal DOPAC/dopamine ratio and(iii)led to increased dopamine transporter levels in the lesioned *** present results suggest that the combination of exercise and docosahexaenoic acid may act synergistically in the striatum of mice with a unilateral lesion of the dopaminergic system and provide support for clinical trials combining nutrition and physical exercise in the treatment of Parkinson’s disease.

关键词： 6-hydroxydopamine dopamine dopamine transporter exercise neurorestoration Parkinson’s disease polyunsaturated fatty acids omega-3

PRECONDItIONED CONJUGAtE GRADIENt MEtHODS FOR INtEGRAL EQUAtIONS OF tHE SECOND KIND DEFINED ON tHE HALF-LINE

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Journal of Computational Mathematics 1996年第3期14卷 223-236页

作者： Chan, RH Lin, fr CHINESE UNIV HONG KONG DEPT MATHSHATINHONG KONG UNIV HONG KONG DEPT MATHHONG KONGHONG KONG

We consider solving integral equations of the second kind defined on the half-line [0, infinity) by the preconditioned conjugate gradient method. Convergence is known to be slow due to the non-compactness of the associated integral operator. In this paper, we construct two different circulant integral operators to be used as preconditioners for the method to speed up its convergence rate. We prove that if the given integral operator is close to a convolution-type integral operator, then the preconditioned systems will have spectrum clustered around 1 and hence the preconditioned conjugate gradient method will converge superlinearly. Numerical examples are given to illustrate the fast convergence.

关键词： Math Cr PRECONDItIONED CONJUGAtE GRADIENt MEtHODS FOR INtEGRAL EQUAtIONS OF tHE SECOND KIND DEFINED ON tHE HALF-LINE Pro III

Hydrogen Reduction and Microstructural Changes of ISF Sinter

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Journal of Materials Science & technology 1996年第5期12卷 389-394页

作者： Hua, YX Sale, fr UNIV MANCHEStER CTR MAT SCIMANCHESTER M1 7HSLANCSENGLAND UNIV MANCHEStER INST SCI & TECHNOLMANCHESTER M1 7HSLANCSENGLAND

the reduction rate and microstructural changes of imperial smelting furnace (ISF) sinter have been investigated by means of thermogravimetric analysis, X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive analysis of X-ray (EDAX) and optical microscope. It is demonstrated that the overall reaction rate of the reduction is influenced by temperature and hydrogen partial pressure in H-2/N-2 gas mixtures. there are two distinct zones observed in the partially reduced sinter. the reduction of zincite proceeds predominantly in a narrow range between the two zones, while the reduction of lead oxide and silicate takes place throughout the sinter. the differences between zincite and lead oxide or silicate in reducibility are analysed by thermodynamics. the phase transformations and microstructural changes occurring during the reduction process are discussed.

关键词： Zinc metallurgy

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

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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.

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Physico-chemical and mechanical properties of ti_3SiC_2-based materials elaborated from SiC/ti by reactive spark plasma sintering

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Journal of Advanced Ceramics 2019年第1期8卷 47-61页

作者： Faten tURKI Houyem ABDERRAZAK frédéric SCHOENStEIN Florent têtARD Mohieddine ABDELLAOUI Noureddine JOUINI Laboratoire des Matériaux Utiles Institut National de Recherche et d’Analyse Physico-chimique Laboratoire de Sciences des Procédés et Matériaux Université Paris 13 Sorbonne Paris Cité CNRS

In this paper, the synthesis of ti_3 SiC_2 from SiC/ti powder using reactive spark plasma sintering(R-SPS) in the temperature range of 1300-1400 ℃ is reported. the results show that the purity of ti_3 SiC_2 is improved up to 75 wt% when the holding time is increased from 10 to 20 min at1400 ℃. the thermodynamic and experimental results indicate that ti_3 SiC_2 formation takes place via the reaction of a pre-formed tiC phase with the silicides, formed from the eutectic *** analysis of mechanical behaviour indicates that samples with higher percentage of secondary phases exhibit higher microhardness and better resistance compared to the near single phase ti_3 SiC_2.

关键词： ti3SiC2 reactive spark plasma sintering(R-SPS) density mechanical properties

Fecal microbiota transplantation in allergic diseases

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World Journal of Methodology 2025年第2期15卷 83-91页

作者： Ece tüsüzÖnata ÖnerÖzdemir Division of Pediatric Allergy and Immunology Medical FacultySakarya UniversityAdapazarı54100SakaryaTürkiye

Microorganisms such as bacteria,fungi,viruses,parasites living in the human intestine constitute the human intestinal *** refers to composi-tional and quantitative changes that negatively affect healthy gut *** recent years,with the demonstration that many diseases are associated with dysbiosis,treatment strategies targeting the correction of dysbiosis in the treat-ment of these diseases have begun to be *** microbiota trans-plantation(FMt)is the process of transferring faeces from a healthy donor to another recipient in order to restore the gut microbiota and provide a therapeutic *** studies have gained popularity after probiotic,prebiotic,symbiotic studies in the treatment of dysbiosis and related *** has emerged as a potential new therapy in the treatment of allergic diseases as it is associated with the maintenance of intestinal microbiota and immunological balance(t helper 1/t helper 2 cells)and thus suppression of allergic *** this article,the definition,application,safety and use of FMt in allergic diseases will be discussed with current data.

关键词： Microbiota Dysbiosis Faecal microbiota transplantation Allergic diseases

Coordination of Schwann cell myelination and node formation at the transcriptional level

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Neural Regeneration Research 2022年第6期17卷 1269-1270页

作者： franziska fröb Michael Wegner Institut für Biochemie Emil-Fischer-ZentrumFriedrich-Alexander-Universität Erlangen-NürnbergErlangenGermany

Formation of the node of Ranvier as a highly coordinated event:Saltatory conduction ensures that information in the vertebrate nervous system is rapidly transmitted over large distances and efficiently processed in complex *** requires the insulation of axonal segments by myelin and the formation of highly structured nodes of Ranvier that are interspersed at regular intervals between successive myelin sheaths and regenerate the action potential as it propagates along the nerve(Rasband and Peles,2021).

关键词： successive insulation conduction

A verification framework for spatio-temporal consistency language with CCSL as a specification language

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frontiers of Computer Science 2020年第1期14卷 105-129页

作者： Yuanrui ZHANG frédéric MALLEt Yixiang CHEN MoE Engineering Research Center for Software/Hardware Co-design technology and Application East China Normal UniversityShanghai 200062China University Nice Sophia Antipolis I3SUMR 7271 CNRSINRIA06900 Sophia AntipolisFrance

the Spatio-temporal Consistency Language(SteC)is a high-level modeling language that deals natively with spatio-temporal behaviour,i.e.,behaviour relating to certain locations and *** restriction by both locations and time is of first importance for some types of real-time *** is a formal specification language based on logical *** is used to describe some crucial safety properties for real-time systems,due to its powerful expressiveness of logical and chronometric time *** consider a novel verification framework combining SteC and CCSL,with the advantages of addressing spatio-temporal consistency of system behaviour and easily expressing some crucial time *** propose a theory combining these two languages and a method verifying CCSL properties in SteC *** adopt UPPAAL as the model checking tool and give a simple example to illustrate how to carry out verification in our framework.

关键词： spatio-temporal consistency real-time systems spatio-temporal systems high-level modelling language clock constraint specification model checking verification framework