- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Construction of a Novel Fluorescent Probe for On-site Measuring Hydrogen Sulfide Levels in Food Samples
摘要： Hydrogen sulfide (H2S) has been involved in many foodstuffs and beverages. On-site measuring the H2S level in food samples was beneficial to the concerns about food safety and food quality. Herein, we rationally constructed a novel fluorescent probe to track the H2S levels in various food samples. The optical experiments indicated that the probe displayed highly selective and sensitive response to H2S. In addition, the probe can function well in a wide pH value condition, providing a reliable platform to sense H2S. The practical application demonstrated that the probe was applied for tracking H2S levels in banana, grape, and vinegar for the first time. Importantly, by fabricating test strips, the probe was first served to monitor the released H2S in raw meat without relying on elaborate instrumentation. Thus, the probe could be employed as a simple tool to measure the H2S levels in various food samples, as well as to monitor the fresh-like quality of raw meat under on-site conditions.
关键词： Fluorescent probe,On-site measurement,Hydrogen sulfide,Food sample,Test strip
更新于2025-09-23 15:23:52
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Infrared Image Reconstruction Based on Archimedes Spiral Measurement Matrix
摘要： It is a new research direction to realize infrared (IR) image reconstruction using compressed sensing (CS) theory. In the field of CS, the construction of measurement matrix is very principal. At present, the types of measurement matrices are mainly random and deterministic. The random measurement matrix can well satisfy the property of measurement matrix, but needs a large amount of storage space and has an inconvenient in hardware implementation. Therefore, a deterministic measurement matrix construction method is proposed for IR image reconstruction in this paper. Firstly, a series of points are collected on Archimedes spiral to construct a definite sequence; then the initial measurement matrix is constructed; finally, the deterministic measurement matrix is obtained according to the required sampling rate. Simulation results show that the IR image could be reconstructed by the measured values obtained through the proposed measurement matrix. Moreover, the proposed measurement matrix has better reconstruction performance compared with the Gaussian and Bernoulli random measurement matrices.
关键词： deterministic measurement matrices,compressed sensing (CS),infrared image reconstruction
更新于2025-09-23 15:23:52
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Three-dimensional reconstruction of incident shock/boundary layer interaction using background-oriented schlieren
摘要： To study the three-dimensional flow structure of an incident shock/boundary layer interaction, a M2.7 nozzle model with a ramp was tested based on the background-oriented schlieren (BOS) technique. After comparing the results of CFD, shear-sensitive liquid crystal (SSLC), and high-speed schlieren, we conclude that BOS can capture the internal structure of the flow field and that its results are consistent with those of other methods in which the relative error can be controlled to 7%. In this research, a new type of experiment with several light paths was used with BOS technology. Three-dimensional reconstruction of incident oblique shock (primarily the width of Mach stem of the shock wave) and quantitative results of the flow field can be obtained successfully, and BOS shows great potential for the measurement of flow fields.
关键词： visualization of flow fields,3D reconstruction,Background-oriented schlieren,quantitative measurement
更新于2025-09-23 15:23:52
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Multichannel image contrast enhancement based on linguistic rule-based intensificators
摘要： This study follows the direct approach to image contrast enhancement, which changes the image contrast at each its pixel and is more effective than the indirect approach that deals with image histograms. However, there are only few studies following the direct approach because, by its nature, it is very complex. Additionally, it is difficult to develop an effective method since it is required to keep a balance in maintaining local and global image features while changing the contrast at each individual pixel. Moreover, raw images obtained from many sources randomly influenced by many external factors can be considered as fuzzy uncertain data. In this context, we propose a novel method to apply and immediately handle expert fuzzy linguistic knowledge of image contrast enhancement to simulate human capability in using natural language. The formalism developed in the study is based on hedge algebras considered as a theory, which can immediately handle linguistic words of variables. This allows the proposed method to produce an image contrast intensificator from a given expert linguistic rule base. A technique to preserve global as well as local image features is proposed based on a fuzzy clustering method, which is applied for the first time in this field to reveal region image features of raw images. The projections of the obtained clusters on each channel are suitably aggregated to produce a new channel image considered as input of the pixelwise defined operators proposed in this study. Many experiments are performed to demonstrate the effect of the proposed method versus the counterparts considered.
关键词： interpolation inference method,contrast measurement,image contrast enhancement,hedge algebra,linguistic rule-based knowledge
更新于2025-09-23 15:23:52
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Superstructure Fiber Bragg Gratings for Simultaneous Temperature and Strain Measurement
摘要： A new and simple fiber optic sensor based on a superstructure fiber Bragg grating (SFBG) for simultaneous temperature and strain measurement is proposed. The SFBG is a superimposed grating for which a long period fiber grating (LPG) and a fiber Bragg grating (FBG) is written in the same section of a Corning SMF-28 fiber. The reflection spectrum of the SFBG possesses two resonant peaks and a trough. By measuring the wavelength shift of the main resonant peak and the reflection power change of the trough, temperature and strain can be determined simultaneously. The accuracy of the sensor in measuring strain and temperature is estimated to be ±13.01 με in a range from 0 με to 1000 με and ±0.75 ℃ from 20 ℃ to 100 ℃, respectively.
关键词： CO2 laser,SFBG,simultaneous measurement of temperature and strain,fiber optic sensor
更新于2025-09-23 15:23:52
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Pre-treatment for preventing degradation of measurement accuracy from speckle noise in speckle interferometry
摘要： Speckle interferometers, which can measure three-dimensional deformations with the same sensitivity in each direction of a three-dimensional axis, have been employed in the industry. However, the measurement results of a complex shape deformation using this method do not always produce a smooth phase map due to the influence of speckle noise. In this paper, this problem that occurs with speckle noise, which is included in the speckle pattern, is discussed. In addition, the solution to the problem concerning speckle noise is discussed. An idea for noise reduction is proposed by using a simple speckle pattern intensity distribution model based on the interferometry. It is confirmed that the proposed method can reduce the influence of speckle noise to 1/1000 of the light source wavelength.
关键词： Noise reduction,Influence of speckle noise,High resolution deformation measurement,ESPI (electronic speckle pattern interferometry)
更新于2025-09-23 15:23:52
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[IEEE 2018 20th International Conference on Transparent Optical Networks (ICTON) - Bucharest (2018.7.1-2018.7.5)] 2018 20th International Conference on Transparent Optical Networks (ICTON) - High-Frame-Rate Single-Shot Spectrum Measurement for Ultrafast Optical Pulses Based on Optical Signal Processing
摘要： The pulse-by-pulse single-shot spectrum measurement for high-repetition rate optical pulses with femtosecond or picosecond pulse width is important for capturing non-repetitive and rare phenomena of substances. Conventional optical spectrum analyzers cannot acquire the spectrum for each pulse at high-repetition rate without missing due to the low processing speed. Several high-speed optical signal processing techniques can help to acquire pulse-by-pulse single-shot spectrum. The high-speed spectrum measurement using a fiber chromatic dispersion-based time stretch dispersive Fourier Transform (TS-DFT) technique is a powerful tool for such measurements. In this paper, we present a record pulse-by-pulse single-shot spectrum measurement for 1 GHz repetition-rate optical pulses with a less than 67-pm spectral resolution based on the TS-DFT technique.
关键词： time stretch dispersive Fourier Transform,single-shot spectrum measurement,optical signal processing
更新于2025-09-23 15:23:52
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A Novel Method for Compensating Temperature Measurement Error Caused by Dust Using Infrared Thermal Imager
摘要： The dust generated in industrial processes has a serious impact on the accuracy of infrared thermometry, which is also the main reason for the limited use of infrared industrial temperature measurement methods applications. To reduce the influence of dust on infrared temperature measurement, this paper proposes a new method for compensating measurement error caused by dust. Firstly, the source of temperature measurement error caused by dust is analyzed, and a compensation method, in which the dust transmittance is important but difficult to determine, is proposed based on the principle of infrared temperature measurement. Then, to solve the difficulty of determining dust transmittance, we define a spatial temperature level co-occurrence matrix and a neighboring temperature level dependence matrix which can be utilized to extract the infrared thermal image’s texture features affected by dust. Finally, by integrating stacked denoising auto-encoder with optimized parameters and support vector regression, a dust transmittance model is established to determine dust transmittance based on the extracted features. Experimental results indicate that the proposed compensation method can reduce the influence of dust on infrared thermal imager’s accuracy effectively.
关键词： temperature measurement,dust transmittance,dust,texture feature,Compensation model,infrared thermal imager
更新于2025-09-23 15:23:52
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Two-Branch Fiber Link for International Clock Networks
摘要： We present our work on realizing two-branch fiber links enabling multiple-partner clock comparisons in Europe. We report in detail on the setup connecting two long-haul links and report for the relative frequency stability and accuracy. We report on a combined uptime of 90% for our dual-branch link during almost 1 month. We finally discuss the combined uncertainty contribution of the ensemble of the link architecture to a clock comparison. We show that the frequency transfer uncertainty is 2 × 10^{-19}.
关键词： two-way noise compensation,phase measurement,ultrastable frequency transfer,Optical fiber links,phase lock loop
更新于2025-09-23 15:23:52
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Portable, visual, and nondestructive detector integrating Vis/NIR spectrometer for sugar content of kiwifruits
摘要： A portable sugar content detector for intact kiwifruits was developed using a visible/near-infrared spectrometer over the wavelength of 350–1,100 nm as spectra collector, a tablet computer as controller, a micro-halogen lamp as light source, and a self-made “Y” shape optical fiber as light transmitter and light receiver. The software applied to collect spectra, to establish sugar content prediction model, and to predict sugar content of kiwifruits was developed by Java language. Partial least square regression model was established to determine sugar content of kiwifruits. Contrasted with the sugar content obtained by digital refractometer, the root-mean-square error of the developed detector was 0.93% in soluble solids content. The obtained sugar content using the developed detector could be given in 2.5 s. The study shows that the developed portable sugar content detector is a promising tool for on-site or in field nondestructive measurement on sugar content of kiwifruits.
关键词： kiwifruits,portable detector,Vis/NIR spectrometer,nondestructive measurement,sugar content
更新于2025-09-23 15:23:52