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152 results on '"Guo, Yuning"'

3. Exploring Topology of 1D Quasiperiodic Metastructures through Modulated LEGO Resonators

Author

Rosa, Matheus I. N., Guo, Yuning, and Ruzzene, Massimo

Subjects
Physics - Applied Physics, Condensed Matter - Mesoscale and Nanoscale Physics
Abstract

We investigate the dynamics and topology of metastructures with quasiperiodically modulated local resonances. The concept is implemented on a LEGO beam featuring an array of tunable pillar-cone resonators. The versatility of the platform allows the experimental mapping of the beam's Hofstadter-like resonant spectrum, which is the first reported observation for an elastic medium. The non-trivial spectral gaps are classified by evaluating the integrated density of states of the bulk bands, which is experimentally verified through the observation of topological edge states localized at the boundaries. Results also show that the spatial location of the edge states can be varied through the selection of the phase of the resonator's modulation law. The presented results open new pathways for the design of metastructures with novel functionalities going beyond those encountered in periodic media by exploiting aperiodic patterning of local resonances and suggest a simple, viable platform for the observation of a variety of topological phenomena.

Published
2021
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5. Observation of topological gravity-capillary waves in a water wave crystal

Author

Laforge, Nicolas, Laude, Vincent, Chollet, Franck, Khelif, Abdelkrim, Kadic, Muamer, Guo, Yuning, and Fleury, Romain

Subjects
Condensed Matter - Mesoscale and Nanoscale Physics, Physics - Fluid Dynamics
Abstract

The discovery of topological phases of matter, initially driven by theoretical advances in quantum condensed matter physics, has been recently extended to classical wave systems, reaching out to a wealth of novel potential applications in signal manipulation and energy concentration. Despite the fact that many realistic wave media (metals at optical frequencies, polymers at ultrasonic frequencies) are inherently dispersive, topological wave transport in photonic and phononic crystals has so far been limited to ideal situations and proof-of-concept experiments involving dispersionless media. Here, we report the first experimental demonstration of topological edge states in a classical water wave system supporting highly dispersive wave propagation, in the intermediate regime of gravity-capillary waves. We use a stochastic method to rigorously take into account the inherent dispersion and devise a water wave crystal insulator supporting valley-selective transport at topological domain walls. Our measurements, performed with a high-speed camera under stroboscopic illumination, unambiguously demonstrate the possibility of valley-locked transport of water waves., Comment: 4 figures

Published
2019
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32. Study on Deformation Mechanism and Supporting Countermeasures of Compound Roofs in Loose and Weak Coal Roadways

Author

Cao Liming, Lei Fan, Jianfeng Cui, Guo Yuning, Chao Yuan, and Weijun Wang

Subjects
Article Subject, business.industry, 0211 other engineering and technologies, Coal mining, Truss, 02 engineering and technology, Deformation (meteorology), Engineering (General). Civil engineering (General), Stress (mechanics), Mining engineering, Coal, Bearing capacity, TA1-2040, business, Roof, Geology, 021101 geological & geomatics engineering, 021102 mining & metallurgy, Civil and Structural Engineering, Rope
Abstract

This paper considers the 333 return airway of the Gaokeng Coal Mine to analyze the deformation characteristics and failure mechanism of the surrounding rock of the composite roof for a loose and weak coal roadway. The reasons for the large deformation are explored and the superiority of the prestressed truss and anchor rope is compared to ordinary anchor cables from the perspective of mechanics to propose a targeted coal roadway support method. Sinking of the composite roof in the coal roadway is accompanied with a release and transfer of the surrounding rock stress. The pressure of the composite roof transfers to the roadway sides and intensifies the fracture process of the coal body. As a result, the ability to support the composite roof is weakened, and it further bends and sinks to form a vicious cycle that repeats itself. Therefore, the support of the composite roof in the coal roadway should consider the roof, roadway sides, and floor as a single unit to achieve the support goal of reinforcing the roadway sides and roof. Based on the above analysis, a comprehensive control technology with a truss and anchor rope is proposed as the main body and a bolt + anchor cable + metal network as the auxiliary. This technology can improve the integral bearing capacity of the composite roof, strengthen the roadway side structures, and reinforce the roadway sides and roof. Numerical simulation and field application results show that the support scheme can effectively realize safe control of the composite roof in coal roadways.

Published
2020

33. Design, Preparation, and Evaluation of Enteric Coating Formulation of HPMC and Eudragit L100 on Carboxylated Agarose Hydrogel by Using Drug Tartrazine

Author

Muhammad Junaid Khan, Wen-Can Huang, Muhammad Akhlaq, Sajid Raza, Alkassoumi Hassane Hamadou, Guo Yuning, Jianan Sun, and Xiangzhao Mao

Subjects
Article Subject, General Immunology and Microbiology, Sepharose, Hydrogels, General Medicine, Hydrogen-Ion Concentration, General Biochemistry, Genetics and Molecular Biology, Drug Delivery Systems, Hypromellose Derivatives, Polymethacrylic Acids, Medicine, Tartrazine, Research Article
Abstract

Enteric-coated application on drug is used to prevent the drug from inactivation which are degraded by gastric enzyme. The present study is aimed at achieving controlled drug delivery in acidic medium of gastrointestinal tract (GIT) by enteric coating of hydroxy propyl methylcellulose (HPMC) and Eudragit L100 on carboxylated agarose hydrogel, creating a pH-dependent delivery system. Fourier-transformed infrared spectroscopy (FTIR) was for the detection of carboxylic group on agarose hydrogel, and scanning electron microscope (SEM) was used for the determination surface of prepared formulation. To check the pH sensitivity of enteric-coated formulation, different pH solution was used. It was found that the formulation was not dissolved in 1.2 but dissolve in pH 6.8 similarly; hydrogels lacking coating showed that tartrazine was more dissolved in pH 1.2, and less dissolved at pH 6.8. The release of tartrazine from the hydrogels was measured by using spectrophotometer and using a scanning electron microscope to examine the morphology and surface appearance of hydrogel capsules. This study revealed cracks on coated samples, while noncoated samples showed clear appearance with no cracks. Our findings revealed that this method could be useful for the development of an enteric coating drug delivery system.

Published
2022

34. Topological Surface States in a Gyroid Acoustic Crystal.

Author

Guo, Yuning, Rosa, Matheus I. N., and Ruzzene, Massimo

Subjects
*SURFACE states, *NEGATIVE refraction, *CRYSTALS, *SOUND design, *SURFACES (Technology)
Abstract

The acoustic properties of an acoustic crystal consisting of acoustic channels designed according to the gyroid minimal surface embedded in a 3D rigid material are investigated. The resulting gyroid acoustic crystal is characterized by a spin‐1 Weyl and a charge‐2 Dirac degenerate points that are enforced by its nonsymmorphic symmetry. The gyroid geometry and its symmetries produce multi‐fold topological degeneracies that occur naturally without the need for ad hoc geometry designs. The non‐trivial topology of the acoustic dispersion produces chiral surface states with open arcs, which manifest themselves as waves whose propagation is highly directional and remains confined to the surfaces of a 3D material. Experiments on an additively manufactured sample validate the predictions of surface arc states and produce negative refraction of waves at the interface between adjoining surfaces. The topological surface states in a gyroid acoustic crystal shed light on nontrivial bulk and edge physics in symmetry‐based compact continuum materials, whose capabilities augment those observed in ad hoc designs. The continuous shape design of the considered acoustic channels and the ensuing anomalous acoustic performance suggest this class of phononic materials with semimetal‐like topology as effective building blocks for acoustic liners and load‐carrying structural components with sound proofing functionality. [ABSTRACT FROM AUTHOR]

Published
2023
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35. Dual-compressed photoacoustic single-pixel imaging.

Author

Guo, Yuning, Li, Baowen, and Yin, Xiaobo

Subjects
*ACOUSTIC imaging, *OPTICAL modulation, *PHOTOACOUSTIC spectroscopy, *THREE-dimensional imaging, *OPTICAL resolution, *SPATIAL resolution
Abstract

Photoacoustic imaging, an acoustic imaging modality with potentially optical resolution in an optical turbid medium, has attracted great attention. However, the convergence of wavefront optimization and raster scanning in computational photoacoustic imaging leads to the challenge of fast mapping, especially for a spatial resolution approaching the acoustic deep-subwavelength regime. As a sparse sampling paradigm, compressive sensing has been applied in numerous fields to accelerate data acquisition without significant quality losses. In this work, we propose a dual-compressed approach for photoacoustic surface tomography that enables high-efficiency imaging with 3D spatial resolution unlimited by the acoustics in a turbid environment. The dual-compressed photoacoustic imaging with single-pixel detection, enabled by spatially optical modulation with synchronized temporally photoacoustic coding, allows decoding of the fine optical information from the modulated acoustic signal even when the variance of original photoacoustic signals is weak. We perform a proof-of-principle numerical demonstration of dual-compressed photoacoustic imaging, that resolves acoustic sub-acoustic-wavelength details with a significantly reduced number of measurements, revealing the potential for dynamic imaging. The dual-compressed concept, which transforms unobtrusive spatial difference into spatio-temporal detectable information, can be generalized to other imaging modalities to realize efficient, high-spatial-resolution imaging. [ABSTRACT FROM AUTHOR]

Published
2023
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38. Improvement of focused ultrasonic beam generated by laser phased array: Theoretical analysis.

Author

Chang, Ying, Yang, Dexing, and Guo, Yuning

Subjects
MICROWAVE attenuation, LASER beams, LASER pulses, THERMOELASTICITY, ULTRASONIC effects
Abstract

To improve the focused ultrasonic beam induced by laser phased array (LPA), the superiority of an improved LPA distribution with conjunction of geometric attenuation and directivity functions of the stimulated ultrasonic beams are investigated theoretically instead of only considering the directivity function. Numerical simulations for the generation of focused longitudinal waves in the thermoelastic regime were implemented to reveal the advantages of the improved LPA design. It is shown that the amplitude of the focused beam increased by 42.1%, and the rise time reduced by 25.0%, as well as spatial sizes narrowed by 50.6% and 41.9% in longitudinal and transverse directions, respectively. In addition, the thermal expansion superposition caused by adjacent laser pulses, which deteriorates the focusing features of the focused beam, should be avoided by setting proper spacing of LPA. [ABSTRACT FROM AUTHOR]

Published
2019
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39. Transformer-IC: The Solution to Information Loss

Author

Wenqian Shang, Zhigang Song, Jiazhao Chai, and Guo Yuning

Subjects
Machine translation, business.industry, Computer science, Information technology, computer.software_genre, Machine learning, Information science, Data modeling, Linguistic Data Consortium, Artificial intelligence, business, computer, Reference model, Arithmetic mean, Transformer (machine learning model)
Abstract

With the development of information technology, machine translation technologies play a crucial role in cross-language communication. However, there is a problem of information loss in machine translation. In view of the common problem, this paper proposes three Transform-Information Combination (Transformer-IC) models based on information combination method. The models are based on the Transformer and select different middle-layer information to compensate the output through arithmetic mean combination method, linear transformation method and multi-layer information combination method respectively. Experimental results based on Linguistic Data Consortium (LDC) Chinese-to-English corpus and International Workshop on Spoken Language Translation (IWSLT) English-to-German corpus show that the BLEU values of all kinds of Transformer-IC model are higher than that of the reference model, in particular the arithmetic mean combination method improves the BLEU value by 1.9. Compared with the Bert model, the results show that even though the Bert model has a good performance, the Transformer-IC models are better than the Bert model. Transformer-IC models can make full use of the middle-layer information and effectively avoid the problem of information loss.

Published
2021

41. A new closed-form algorithm for 3-D single near-field source

Author

Guo Yuning, Yezi Ma, Wanchun Li, Min Wang, and Yingxiang Li

Subjects
Physics, Computer Networks and Communications, Estimation theory, 020208 electrical & electronic engineering, 020206 networking & telecommunications, Near and far field, 02 engineering and technology, Electronic, Optical and Magnetic Materials, Computational physics, Azimuth, 0202 electrical engineering, electronic engineering, information engineering, Range (statistics), Electrical and Electronic Engineering, Instrumentation
Abstract

Recently, a single source location problem has attracted special attention in many previous works. A method was lately proposed to estimate three-dimensional (3-D) parameters (i.e. range, azimuth a...

Published
2019

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