| 1. |
- Huang, Chujun, et al.
(författare)
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Fusion models for detection of soluble solids content in mandarin by Vis/ NIR transmission spectroscopy combined external factors
- 2022
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Ingår i: Infrared physics & technology. - : Elsevier. - 1350-4495 .- 1879-0275. ; 124
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Tidskriftsartikel (refereegranskat)abstract
- In the process of acquiring the visible/near infrared (Vis/NIR) spectra of mandarin to predict the soluble solids content (SSC), spectra information is often influenced by the physical property of citrus. Thereupon affects the accuracy and robustness of the SSC prediction model. Calibration models were established by partial least squares (PLS) regression methods based on three spectral measurement orientations (Mandarin calyx-stem axis vertical with stem upward (A); Mandarin calyx-stem axis vertical with stem downward (B); Mandarin calyx-stem axis horizontal (C)) respectively. Novel methods that considering mandarin external factors (diameter, color and peel thickness) were established. The methods were associated with wavelength selection algorithms and their combination with alternative methods to build multivariate regression models. After evaluating the models, the model performance was improved by the external factor inclusion methods, among which the color and diameter united inclusion method combined with ACO-PLS algorithm performed the best, with Rp = 0.987 and RMSEP = 0.19 degrees Brix for its prediction model. This study serves as a reference and theoretical support for determining the influencing factors that affect fruit internal quality determination using near infrared spectroscopy.
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| 2. |
- Yang, Haolin, et al.
(författare)
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Watt-level 1.6 μm dissipative soliton ultrafast laser and external generation of ∼70 fs noise-like pulses for supercontinuum generation
- 2023
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Ingår i: Infrared physics & technology. - : Elsevier BV. - 1350-4495 .- 1879-0275. ; 134
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Tidskriftsartikel (refereegranskat)abstract
- Here, we propose a high power dissipative soliton (DS) laser with a central wavelength of ∼1612 nm. The whole laser system includes the mode-locking oscillator and the corresponding master oscillator power amplifier (MOPA). The mode-locking oscillator is a nonlinear amplifier loop mirror (NALM) cavity, which has a net normal dispersion enabling the generation of nJ-level DS pulses. To further enhance the output power of the 1.6 μm DS pulses, the specially-designed MOPA system consisting of multiple-stage single-pass amplifier is constructed, which can amplify the output power to watt level and meanwhile keeps a high suppression ratio to C-band amplified spontaneous emission (ASE). This high power 1.6 μm DS laser will have further applications in biomedical research and material processing. In the amplifier, we observe the automatic evolution of the DS pulses into the noise-like (NL) pulses under high pumping strength. At the maximum pump power, the MOPA system delivers the NL pulses with an output power of over 2 W. The narrowest spike duration is ∼70 fs (fs). This 1.6 μm fs-scale NL laser is a good pump source for generating the mid-infrared supercontinuum without short wavelength region loss. To demonstrate the superiority of this NL laser, a broad supercontinuum from ∼0.87 μm to ∼3.75 μm waveband is achieved with a piece of highly germanium-doped (Ge-doped) fiber.
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