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  • 1
    Online Resource
    Online Resource
    Hindawi Limited ; 2018
    In:  Advances in Civil Engineering Vol. 2018 ( 2018), p. 1-15
    In: Advances in Civil Engineering, Hindawi Limited, Vol. 2018 ( 2018), p. 1-15
    Abstract: The influence of acid solution and immersion time on the physicomechanical properties of sandstone is investigated. Uniaxial compression tests on sandstone samples are conducted to determine the variations of relative mass, deformation, and strength characteristics of sandstone subjected to different pH sulfuric acid corrosion values. The changes of pH and Mg 2+ and Ca 2+ concentration of immersion solutions are monitored during soaking. The corrosion mechanism of sandstone attacked by the acid solution is discussed with the results of SEM tests. Based on the nondestructive CT scanning test, the damage variables of acid-corroded sandstone are deduced, and the damage degree of sandstone is quantitatively analyzed. The results indicate that the deformation characteristics of sandstone samples under acid attack are characterized by the softening of rock, and the softening degree gradually increases with the increase of the acidity and the soaking time. The peak strength of sandstone samples declines as soaking time extends. The chemical effects lead to a large amount of dissolution of the rock mineral assemblage, resulting in the large-scale development of the pores inside the rock, which changes the macroscopic mechanical properties. The damage variables of acid corrosion sandstone based on CT numbers are deduced, and the quantitative relationship between damage variables and immersion time is established, which provides a basis for constructing a damage constitutive model of sandstone in the acidic environment.
    Type of Medium: Online Resource
    ISSN: 1687-8086 , 1687-8094
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2018
    detail.hit.zdb_id: 2449760-5
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  • 2
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2016
    In:  Scientific Reports Vol. 6, No. 1 ( 2016-11-09)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 6, No. 1 ( 2016-11-09)
    Abstract: The study of synchronization in generalized Kuramoto models has witnessed an intense boost in the last decade. Several collective states were discovered, such as partially synchronized, chimera, π or traveling wave states. We here consider two populations of globally coupled conformist and contrarian oscillators (with different, randomly distributed frequencies), and explore the effects of a frequency–dependent distribution of the couplings on the collective behaviour of the system. By means of linear stability analysis and mean–field theory, a series of exact solutions is extracted describing the critical points for synchronization, as well as all the emerging stationary coherent states. In particular, a novel non-stationary state, here named as Bellerophon state , is identified which is essentially different from all other coherent states previously reported in the Literature. A robust verification of the rigorous predictions is supported by extensive numerical simulations.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2016
    detail.hit.zdb_id: 2615211-3
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  • 3
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2015
    In:  Scientific Reports Vol. 5, No. 1 ( 2015-12-14)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 5, No. 1 ( 2015-12-14)
    Abstract: Two decades ago, a phenomenon resembling Landau damping was described in the synchronization of globally coupled oscillators: the evidence of a regime where the order parameter decays when linear theory predicts neutral stability for the incoherent state. We here show that such an effect is far more generic, as soon as phase oscillators couple to their mean field according to their natural frequencies, being then grouped into two distinct populations of conformists and contrarians . We report the analytical solution of this latter situation, which allows determining the critical coupling strength and the stability of the incoherent state, together with extensive numerical simulations that fully support all theoretical predictions. The relevance of our results is discussed in relationship to collective phenomena occurring in social and economical systems.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2015
    detail.hit.zdb_id: 2615211-3
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  • 4
    Online Resource
    Online Resource
    Elsevier BV ; 2014
    In:  Procedia Engineering Vol. 80 ( 2014), p. 479-493
    In: Procedia Engineering, Elsevier BV, Vol. 80 ( 2014), p. 479-493
    Type of Medium: Online Resource
    ISSN: 1877-7058
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2014
    detail.hit.zdb_id: 2509658-8
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  • 5
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2018
    In:  Scientific Reports Vol. 8, No. 1 ( 2018-08-28)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 8, No. 1 ( 2018-08-28)
    Abstract: Macroscopic rhythms are often signatures of healthy functioning in living organisms, but they are still poorly understood on their microscopic bases. Globally interacting oscillators with heterogeneous couplings are here considered. Thorough theoretical and numerical analyses indicate the presence of multiple phase transitions between different collective states, with regions of bi-stability. Novel coherent phases are unveiled, and evidence is given of the spontaneous emergence of macroscopic rhythms where oscillators’ phases are always found to be self-organized as in Bellerophon states, i.e. in multiple clusters with quantized values of their average frequencies. Due to their rather unconditional appearance, the circumstance is paved that the Bellerophon states grasp the microscopic essentials behind collective rhythms in more general systems of interacting oscillators.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2018
    detail.hit.zdb_id: 2615211-3
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  • 6
    Online Resource
    Online Resource
    Hindawi Limited ; 2020
    In:  Advances in Civil Engineering Vol. 2020 ( 2020-07-30), p. 1-15
    In: Advances in Civil Engineering, Hindawi Limited, Vol. 2020 ( 2020-07-30), p. 1-15
    Abstract: The physicomechanical deterioration characteristics of sandstone subjected to H 2 SO 4 , HCl, and H 2 O solutions of different pH values are studied by the method of long-term accelerated immersion. The quantitative relationships between the damage variables based on CT (computer tomographic identification technology) numbers and the immersion time, the uniaxial compressive strength, the peak point strain, and the elastic modulus of rock samples are analyzed. The test results indicate that the pH value of immersion solutions, the dissolution rate of Ca 2+ and Na + , and the quality change of rock samples show visible stage characteristics under acidic environment. With the soaking time extended, the pH value of solutions increases gradually, and the quality change of rock samples decreases gradually. The smaller the pH value of immersion solutions is, the higher the dissolution rate of Ca 2+ and Na + is. However, the cation dissolution rate under a weak acid environment with a high pH value has little difference with that under the distilled water (pH = 7). With the increase of the soaking time and the acidity, the compaction stage of rock samples becomes longer, the elastic stage becomes shorter, the deterioration degree of mechanical parameters becomes more extensive, and the destruction of sandstone samples shows ductility characteristics increasingly. The corrosion degree of corroded sandstone samples is quantitatively represented by microscopic damage variables based on CT numbers. The regression analysis results show that damage variables of acid-corroded sandstone samples have a power function relationship with soaking time and an exponential function relationship with peak strength, peak point strain, and elastic modulus.
    Type of Medium: Online Resource
    ISSN: 1687-8086 , 1687-8094
    Language: English
    Publisher: Hindawi Limited
    Publication Date: 2020
    detail.hit.zdb_id: 2449760-5
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  • 7
    Online Resource
    Online Resource
    IOP Publishing ; 2019
    In:  New Journal of Physics Vol. 21, No. 5 ( 2019-05-01), p. 053002-
    In: New Journal of Physics, IOP Publishing, Vol. 21, No. 5 ( 2019-05-01), p. 053002-
    Abstract: When large ensembles of phase oscillators interact globally, and when bimodal frequency distributions are chosen for the natural frequencies of the oscillators themselves, Bellerophon states are generically observed at intermediate values of the coupling strength. These are multi-clustered states emerging in symmetric pairs. Oscillators belonging to a given cluster are not locked in their instantaneous phases or frequencies, rather they display the same long-time average frequency (a sort of effective global frequency). Moreover, Bellerophon states feature quantized traits, in that such average frequencies are all odd multiples (±(2 n  − 1), n  = 1, 2...) of a fundamental frequency Ω 1 . We identify and investigate (analytically and numerically) several typical bifurcation paths to synchronization, including first-order and second-order-like. Linear stability analysis allows to successfully solve the critical transition point for synchronization. Our results highlight that the spontaneous setting of higher order forms of coherence could be achieved in classical Kuramoto model.
    Type of Medium: Online Resource
    ISSN: 1367-2630
    Language: Unknown
    Publisher: IOP Publishing
    Publication Date: 2019
    detail.hit.zdb_id: 1464444-7
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  • 8
    Online Resource
    Online Resource
    American Physical Society (APS) ; 2019
    In:  Physical Review E Vol. 100, No. 5 ( 2019-11-25)
    In: Physical Review E, American Physical Society (APS), Vol. 100, No. 5 ( 2019-11-25)
    Type of Medium: Online Resource
    ISSN: 2470-0045 , 2470-0053
    RVK:
    Language: English
    Publisher: American Physical Society (APS)
    Publication Date: 2019
    detail.hit.zdb_id: 2844562-4
    SSG: 12
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  • 9
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2016
    In:  Scientific Reports Vol. 6, No. 1 ( 2016-02-23)
    In: Scientific Reports, Springer Science and Business Media LLC, Vol. 6, No. 1 ( 2016-02-23)
    Abstract: Recently, the first-order synchronization transition has been studied in systems of coupled phase oscillators. In this paper, we propose a framework to investigate the synchronization in the frequency-weighted Kuramoto model with all-to-all couplings. A rigorous mean-field analysis is implemented to predict the possible steady states. Furthermore, a detailed linear stability analysis proves that the incoherent state is only neutrally stable below the synchronization threshold. Nevertheless, interestingly, the amplitude of the order parameter decays exponentially (at least for short time) in this regime, resembling the Landau damping effect in plasma physics. Moreover, the explicit expression for the critical coupling strength is determined by both the mean-field method and linear operator theory. The mechanism of bifurcation for the incoherent state near the critical point is further revealed by the amplitude expansion theory, which shows that the oscillating standing wave state could also occur in this model for certain frequency distributions. Our theoretical analysis and numerical results are consistent with each other, which can help us understand the synchronization transition in general networks with heterogenous couplings.
    Type of Medium: Online Resource
    ISSN: 2045-2322
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2016
    detail.hit.zdb_id: 2615211-3
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  • 10
    Online Resource
    Online Resource
    Springer Science and Business Media LLC ; 2022
    In:  Arabian Journal of Geosciences Vol. 15, No. 6 ( 2022-03)
    In: Arabian Journal of Geosciences, Springer Science and Business Media LLC, Vol. 15, No. 6 ( 2022-03)
    Type of Medium: Online Resource
    ISSN: 1866-7511 , 1866-7538
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2022
    detail.hit.zdb_id: 2438771-X
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