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1

Controllable wavelength conversion based on soliton dynamics in mid-infrared fiber

Shen Kangle, Yang Jian, Zhao Jiayi, Yang Xinyu, Yang Hua

Optica Applicata

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2023

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Vol. 53, nr 3

419--429

EN

We provide a convenient way to actively control the wavelength conversion of probe waves based on the soliton dynamics in the As2S3 fibers. In this paper, it is found by numerical calculation that wavelength conversion occurs in the frequency domain due to the existence of refractive index barrier. By adjusting the collision position of pump pulse and probe pulse to realize the conversion of probe pulse wavelength, the effect of the power and the incident wavelength of the probe wave on the wavelength conversion are also discussed. This frequency domain conversion is of great use in the mid-infrared region, for example, all-optical conversion switches.

2

Deformation and failure laws and acoustic emission characteristics of low‑strength molybdenum ore

Zhao Kang, Yang Jian, Song Yufeng, Wang Qing, Zhao Kangqi, Ji Yongbo

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 2

art. no. e74, 2023

EN

Uniaxial compression acoustic emission (AE) tests were conducted on low-strength molybdenum ore (LSMO) to investigate its deformation and failure laws and AE characteristics. The stress-strain curve and AE parameter data of LSMOs were obtained by uniaxial compression AE test, and the relationships of stress, AE parameter, amplitude fractal dimension, and AE b value with loading time were analyzed accordingly to obtain the general law of their deformation and failure and a series of AE characteristics. The research shows that under the action of uniaxial stress, the failure mode of LSMOs mainly shows brittle failure, and the failure form mainly shows monoclinic shear failure. The stress-strain curve shows obvious plastic-elastic deformation, the plastic deformation time is long, and the division of each stage of deformation failure is not obvious. The simultaneous occurrence of large surges in ringing count and energy to higher orders of magnitude can be used as precursor information for failure destabilization of LSMOs. The evolution process of AE parameters of LSMO corresponds well with its deformation and failure process, and the variation pattern of ringing counts and energy shows a high consistency. With increasing stress, the amplitude correlation dimension and b value are mainly in the form of "falling-rising-falling-fluctuating". The results of the study can provide some theoretical basis for the assessment of the stability of the mine surrounding rock and the determination of a reasonable and effective reinforcement plan.

3

Probabilistic seismic performance evaluation of composite frames with concrete-filled steel tube columns and buckling-restrained braces

Li Beibei, Wang Jingfeng, Yang Jian, Wang Yuanqing

Archives of Civil and Mechanical Engineering

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2021

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Vol. 21, no. 2

541--562

EN

The concrete-filled steel tube (CFT) composite frames using blind bolts and buckling-restrained braces (BRBs) have been studied with the development of building industrialization and energy dissipation technology. However, there has been no research so far on the probabilistic seismic fragility analysis for the blind-bolted end-plate CFT composite frames with BRBs (BRB-BECFT). Therefore, a total of 6-, 9-, 12- and 20-story BRB-BECFT prototype structures were designed based on the performance-based plastic design method. The results obtained from nonlinear static and dynamic analyses indicated that the four structures achieved predefined performance objectives in terms of story drift, joint rotation, and BRB ductility demand. Subsequently, fragility curves including non-collapse and collapse states were established to evaluate the behavior of the structure for a given intensity measure using the incremental dynamic analysis approach. Meanwhile, the geometric mean of spectral acceleration over a period range (Sa,avg) was selected as the intensity measure to assess the structural collapse capacity. Results showed that the adoption of Sa,avg can result in 32–42% lower data dispersion for the determination of collapse point, and simplification of the process of calculation of the collapse margin ratio of a structure. Furthermore, based on the combination of Sa,avg, residual story drift and BRB core plate strain, a framework of probabilistic seismic damage analysis of structures for combined damage evaluation at three levels of the system, subsystem, and component was summarized and conducted by the 6- and 12-story case study. This is practically useful to assess structural damage state after an earthquake because it could present more information on the probability distribution of various damage scenarios.