- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- 2018
- infrared image
- target detection
- lucas–kanade method (LK)
- local contrast method (LCM)
- facet model
- target detection
- zero-crossing point
- Image processing
- Infrared camera
- Eye movement
- Optoelectronic Information Science and Engineering
- Chinese Academy of Sciences
- Gunma University
- University of Chinese Academy of Science
- Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Science
- University of Science and Technology of China
- Space Star Technology Co. LTD
-
Potential of Near Infrared Spectroscopy for Classification of Different Delignificant Pre-Treatments on Banana Rachis
摘要： Delignificant pretreatments are fundamental in lignocellulosic materials preprocessing to remove lignin from biomass. Current wet chemical methods are time-consuming, labor-intensive and use hazardous reagents. Near Infrared Spectroscopy (NIRS) provides rapid and non-destructive analysis, and has shown promising results. Spectra collection (8000-4000 cm-1), combined with chemometric analysis based on Cluster Analysis and Principal Component Analysis, has allowed to perform qualitative study of banana rachis, a lignocellulosic residue of agricultural production.
关键词： Near infrared spectroscopy,Cluster analysis,Delignification,Pre-treatments,Banana rachis
更新于2025-09-09 09:28:46
-
Dense restructuring of amorphous silicon network induced by non-bonded hydrogen
摘要： We con?rmed the presence of non-bonded hydrogens (NBHs) in hydrogenated amorphous silicon (a-Si:H) ?lms, using a combination of multiple techniques (Rutherford backscattering spectrometry/hydrogen forward scattering, Fourier-transform infrared spectroscopy-attenuated total re?ection, and thermal desorption spectrometry). The hydrogen e?usion pro?le of an a-Si:H ?lm with large amounts of NBHs was analyzed in detail. We report the e?ect of NBHs on band structure and electrical conductivity, and we present additional considerations for previous data on number density of silicon, optical bandgap, and vacancy size distribution [J. Non-Cryst. Solids 447, 207 (2016)]. The e?ect of NBHs on the a-Si network is explained by the “dense restructuring model”.
关键词： thermal desorption spectrometry,Rutherford backscattering spectrometry,hydrogenated amorphous silicon,non-bonded hydrogens,dense restructuring model,Fourier-transform infrared spectroscopy
更新于2025-09-09 09:28:46
-
Individual optimal attentional strategy during implicit motor learning boosts frontoparietal neural processing efficiency: A functional near-infrared spectroscopy study
摘要： Introduction: Optimal focus of attention is a crucial factor for improving motor learning. Most previous studies have shown that directing attention to movement outcome (external focus; EF) is more effective than directing attention to body movement itself (internal focus; IF). However, our recent studies demonstrated that the optimal attentional strategy in healthy and clinical populations varies depending on individual motor imagery ability. To explore the neurological basis underlying individual optimal attentional strategy during motor learning tasks, in the present study, we measured frontoparietal activities using functional near‐infrared spectroscopy (fNIRS). Methods: Twenty‐eight participants performed a visuomotor learning task requiring circular tracking. During the task, the participants were required to direct their attention internally or externally. The individual optimal attentional strategy was determined by comparing the after‐effect sizes between the IF and EF conditions. Results: Fifteen participants showed larger after‐effects under the EF condition (External‐dominant), whereas the others showed larger after‐effects under the IF condition (Internal‐dominant). Based on the differences in neural activities between Internal‐ and External‐dominant groups, we identified the right dorsolateral prefrontal cortex (Brodmann area 46) and right somatosensory association cortex (Brodmann area 7) as the neural bases associated with individual optimal attentional strategy during motor learning. Furthermore, we observed a significant negative correlation, that is, lower activity in these areas was associated with a larger after‐effect size under the optimal attentional strategy. Conclusion: Our findings demonstrated that more efficient neural processing in the frontoparietal area under the individual optimal attentional strategy can accelerate motor learning.
关键词： individual differences,dorsolateral prefrontal cortex,somatosensory association cortex,visuomotor learning,functional near‐infrared spectroscopy,focus of attention
更新于2025-09-09 09:28:46
-
Utility of lacrimal caruncle infrared thermography when monitoring alterations in autonomic activity in healthy humans
摘要： Purpose Physiological markers that estimate sympathetic activation may be used to infer pain and stress in humans. To date, effective reproducible methods are invasive and pose an undesired risk to participants. Previous work in animal models has used infrared thermography to measure the temperature of the lacrimal caruncle region and may be a promising method for measuring stress and pain non-invasively. The current study aimed to determine whether this method is useful in humans. Methods Sixteen young healthy participants (age: 18–35) were recruited and underwent sympathetic activation using a cold pressor test (CPT) and a muscle chemoreflex (MCR), and completed a control trial. Throughout all trials, infrared thermographic imaging of the lacrimal caruncle, heart rate, heart rate variability, mean arterial blood pressure and pulse transit time were measured. Results Heart rate (MCR: 4 ± 3?bpm, CPT: 17 ± 4?bpm p < 0.01) and mean arterial pressure increased (MCR: 6 ± 2, CPT: 5 ± 2?mmHg, p < 0.01) and pulse transit time decreased (p = 0.03) with both sympathetic activation interventions. However, lacrimal caruncle temperature did not vary under any condition remaining at 35.2 ± 0.2?°C which was similar to baseline. Conclusions Our findings suggest infrared thermographic monitoring of eye temperature in humans does not reliably relate to sympathetic activation. This could be due to hemodynamic responses at the lacrimal caruncle that may be more complex than previously proposed with sympathetic activation. Alternatively, pulse transit time seems like a promising non-invasive measure of changes in sympathetic activation in humans.
关键词： Sympathetic nervous system activation,Muscle chemoreflex,Thermography,Muscle metaboreflex,Infrared imaging
更新于2025-09-09 09:28:46
-
Chemical analysis of in vivo–irradiated dentine of head and neck cancer patients by ATR-FTIR and Raman spectroscopy
摘要： Objectives To evaluate the effect of in vivo radiotherapy on the chemical properties of human dentine by Fourier-transform infrared spectroscopy (FTIR) and Raman analysis. Materials and methods Chemical composition was evaluated comparing control and irradiated group (n = 8). Irradiated teeth were obtained from radiotherapy patients subjected to fractionated X-ray radiation of 1.8 Gy daily totaling 72 Gy. The teeth were sectioned according to the type of dentine (crown or root dentine), obtaining 3-mm dentine cervical slices. The analyzed parameters by FTIR and Raman spectroscopies were mineral/matrix ratio (M:M), carbonate/mineral ratio (C:M), amide I/amide III ratio, and amide I/CH2 ratio. Raman also calculated the phosphate and carbonate crystallinity. Results FTIR revealed that M:M had a decrease in both factors (p = 0.008; p = 0.043, respectively) and root dentine showed a lower C:M in the irradiated group (p = 0.003). Raman revealed a higher phosphate crystallinity and a lower carbonate crystallinity in crown dentine of irradiated group (p = 0.021; p = 0.039). For amide I/amide III, the irradiated showed a lower ratio when compared to the control group (FTIR p = 0.002; Raman p = 0.017). For amide I/CH2, the root dentine showed a higher ratio than the crown dentine in both methods (p < 0.001). Conclusions Radiotherapy altered the chemical composition of human dentine. The exchange of phosphate-carbonate ions in the hydroxyapatite and higher concentration of organic components was found after radiotherapy. Clinical relevance The increased risk of radiation-related caries in patients undergoing head and neck radiotherapy is due not only to salivary, dietary, and microbiological changes but also to changes in tooth chemical composition.
关键词： Radiotherapy,Raman spectroscopy,Head and neck cancer,Fourier-transform infrared spectroscopy,Dentine
更新于2025-09-09 09:28:46
-
Flattened and broadband mid-infrared super-continuum generation in As2Se3 based holey fiber
摘要： By using an As2Se3 based holey fiber (HF) with a normal flat dispersion profiles, a flattened and broadband mid-infrared super-continuum generation is analysed. The transmission of an ultra-short pulse in the HF is numerically simulated by solving the generalized nonlinear Schr?dinger equation under various parameters. The simulation results show that, by launching a pulse with a width of 50 fs and a peak power of 4.25 kW at 4375 nm into the 6 mm-long HF, a flat and broadband super-continuum at 3 dB level is successfully generated. The super-continuum covers the wavelengths from 3866 to 5958 nm which is the largest flat bandwidth reported in such a short fiber.
关键词： Holey fiber,Mid-infrared super-continuum,Normal flat dispersion
更新于2025-09-09 09:28:46
-
Vis-NIR spectroscopy Combined with Wavelengths Selection by PSO Optimization Algorithm for Simultaneous Determination of Four Quality Parameters and Classification of Soy Sauce
摘要： The performance of Vis-NIR techniques combined with variable select by a simple modified particle swarm optimization (PSO) algorithm for the determination of four quality parameters in soy sauce was evaluated. Compared with full-spectral support vector machine regression (Full-SVMR) and SVMR based on competitive adaptive reweighted sampling (CARS-SVM) method, the application of PSO wavelength selection provided a notably improved SVM regression model. The root-mean-square error of amino acid nitrogen, salt, total acid content, and color ratio obtained by PSO-SVMR are 0.0075 g/100 ml, 0.2176 g/100 ml, 0.0077 g/100 ml, and 0.0506 in predicted sets, respectively. The correlation coefficients of predicted sets obtained by PSO-SVMR reached 0.9997, 0.9462, 0.9996, and 0.9998, respectively. Meanwhile, a classification study constructed with principal component analysis and SVM classification model based on the feature wavelengths selected by PSO shows that Vis-NIR spectra can be used to classify soy sauce according to their brands and quality. The result showed that the Vis-NIR spectroscopy technique based on PSO wavelength selection has high potential to predict the quality parameters in a nondestructive way. This analytical tool may also contribute to the detection of fraud and mislabeling in the soy sauce market and certainly contribute to improvement in quality and reliability of the soy sauce market.
关键词： Quality parameters,Wavelength selection,Modified particle swarm optimization algorithm,Visible and near-infrared spectroscopy,Soy sauce
更新于2025-09-09 09:28:46
-
Decorative near-infrared transmission filters featuring high-efficiency and angular-insensitivity employing 1D photonic crystals
摘要： We present a new scheme for visibly-opaque but near-infrared-transmitting filters involving 7 layers based on one-dimensional ternary photonic crystals, with capabilities in reaching nearly 100% transmission efficiency in the near-infrared region. Different decorative reflection colors can be created by adding additional three layers while maintaining the near-infrared transmission performance. In addition, our proposed structural colors show great angular insensitivity up to ±60° for both transverse electric and transverse magnetic polarizations, which are highly desired in various fields. The facile strategy described here involves a simple deposition method for the fabrication, thereby having great potential in diverse applications such as image sensors, anti-counterfeit tag, and optical measurement systems.
关键词： colored decorations,multilayer structures,photonic crystals,near-infrared (NIR)-transmitting filters
更新于2025-09-09 09:28:46
-
In situ Study of EDC/NHS Immobilization on Gold Surface Based on Attenuated Total Reflection Surface-Enhanced Infrared Absorption Spectroscopy (ATR-SEIRAS)
摘要： In this study, the time-dependent reaction between 11-mercaptoundecanoic acid (11-MUA) and 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide/N-hydroxysuccinimide (EDC/NHS) is precisely characterized using surface enhanced infrared absorption spectroscopy (SEIRAS). According to the high correlation between the spectral results of SEIRAS and the electrochemical behavior, it strongly demonstrates that the EDC/NHS reaction would be obviously interfered by phosphate ions in the neutral pH condition (pH = 7.0).
关键词： EDC/NHS,Attenuated Total Reflection (ATR),Surface-Enhanced Infrared Absorption Spectroscopy (SEIRAS)
更新于2025-09-09 09:28:46
-
Numerical investigation and experimental validation of an infrared measurement approach for surface heat flux distribution using a multi-color-reference
摘要： Accurate measurement of heat flux (HF) is significant in both industrial engineering and scientific research. It is acknowledged that the radiative HF can be easily determined by radiometers. In order to measure the conductive or convective HF distribution flowing across a surface, this paper presents a novel non-contact measuring method based on the infrared (IR) technique and inverse heat transfer method (IHTM). In addition, a specially designed multi-color-reference (MCR) which is composed of four sectors with four different known emissivity will be attached to the focused surface in the practical measurement. Therefore, different radiation signals among the four different sectors of MCR as well as the focused surface will be detected by an IR camera, through which a whole radiation temperature map can be obtained. Based on the differences in the radiation temperatures of the surface and MCR, the IHTM can be adopted to yield useful boundary conditions such as emissivity of the surface, convective heat transfer coefficient, and the critical HF distribution. The measuring method presented in this study combines the advantages of contact and non-contact measurement, which can accurately obtain the HF distribution under the difficult-contacted conditions such as the HF monitoring of a boiling furnace, HF estimating of the aerodynamic heating surface, etc. Numerical simulation and experimental verification were organized to justify the newly-developed measuring method. Relative error in the simulation is estimated to be less than 2%, and that in the experiment is calculated to be around 4.23%. The result displays a relatively high precision of the measuring method, demonstrating that such a method can be applied in practical application.
关键词： Infrared technique,Heat flux measurement,Emissivity,Heat transfer,IHTM
更新于2025-09-09 09:28:46