Publications by authors named "Xiaojian Hao"

High-resolution flame temperature images are essential indicators for evaluating combustion conditions. Tunable diode laser absorption spectroscopy (TDLAS) is an effective combustion diagnostic method. In actual engineering, due to the limitation of line-of-sight (LOS) measurement, TDLAS technology has the problems of small data volume and low dimensionality in measuring combustion fields, which seriously limits the development of TDLAS in combustion diagnosis.

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In the brief combustion process of an explosive fireball, the fireball can release considerable radiant energy. Aiming at the problem that the Stephen-Boltzmann formula calculates the fireball surface radiant energy (full band), it does not match the working bands of most infrared thermal imagers. So, in this paper, we obtain dynamic parameters such as the temperature, diameter, and height of the fireball from the infrared thermal image of the thermobaric explosive fireball, achieve on-site atmospheric transmittance by the temperature calibration target, and integrate within the effective wavelength band of the infrared thermal imager, and a precise dynamic model of the fireball's thermal radiation dose was finally established.

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Existing non-contact flame temperature measuring methods depend on complex, bulky and expensive optical instruments, which make it difficult for portable applications and high-density distributed networking monitoring. Here, we demonstrate a flame temperature imaging method based on a perovskite single photodetector. High-quality perovskite film epitaxy grows on the SiO/Si substrate to fabricate the photodetector.

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Wind energy as a renewable energy source is easily available and widely distributed in cities. However, current wind-energy harvesters are inadequate at capturing energy from low-speed winds in urban areas, thereby limiting their application in distributed self-powered sensor networks. A triboelectric-electromagnetic hybrid harvester with a low startup wind speed (LSWS-TEH) is proposed that also provides output power within a wide range of wind speeds.

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With advances in new materials and technologies, there has been increasing research focused on flexible sensors. However, in most flexible pressure sensors made using new materials, it is challenging to achieve high detection sensitivity across a wide pressure range. Although traditional silicon-based sensors have good performance, they are not formable and, because of their rigidity and brittleness, they are not suitable for fitting with soft human skin, which limits their application in wearable devices to collect various signals.

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We demonstrate a perovskite single-phototransistor visible-light spectrometer based on a deep-learning method. The size of the spectrometer is set to the scale of the phototransistor. A photoresponsivity matrix for the deep-learning system is learned from the characteristic parameters of the visible-light wavelength, gate voltage, and power densities of a commercial standard blackbody source.

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In this study, an improved flame edge detector based on convolutional neural network (CNN) was proposed. The proposed method can generate edge graphs and extract edge graphs relatively effectively. Our network architecture was based on VGG16 primarily, the last two max-pooling operators and all full connection layers of the VGG16 network were deleted, and the rest was taken as the basic network.

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To overcome the shortcomings of low detection sensitivity and high spectral line background noise of traditional laser-induced breakdown spectroscopy (LIBS), a method of combining flat mirrors with gold nanoparticles (Au-NPs) was proposed. First, independent plane mirror and Au-NPs experiments were performed by using aluminum alloy samples. After that, the samples were placed under four conditions (None-LIBS; Three mirrors-LIBS; 20 nm Au-NPs-LIBS; 20 nm Au-NPs and Three mirrors-LIBS), and the differences between various spectral parameters were analyzed.

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Resolution is an important index for evaluating the reconstruction performance of temperature distributions in a combustion environment, and a higher resolution is necessary to obtain more precise combustion diagnoses. Tunable diode laser absorption tomography (TDLAT) has proven to be a powerful combustion diagnosis method for efficient detection. However, restricted by the line-of-sight (LOS) measurement, the reconstruction resolution of TDLAT was dependent on the size of the detection data, which made it difficult to obtain sufficient data for extreme environmental measurements.

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In this study, based on the existing high-temperature measurement and calibration equipment, calibration experiments using the spectral emissivity of intrinsic element particles in the field were designed to achieve the accurate measurement of a temperature field. Laser-induced breakdown spectroscopy was used to select the corresponding elements, and the element doping method was used to approximate the real temperature field. After calibrating the camera, the temperature distribution and spectral emissivity distribution of the flame were calculated.

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As a new material, graphene shows excellent properties in mechanics, electricity, optics, and so on, which makes it widely concerned by people. At present, it is difficult for graphene pressure sensor to meet both high sensitivity and large pressure detection range at the same time. Therefore, it is highly desirable to produce flexible pressure sensors with sufficient sensitivity in a wide working range and with simple process.

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In dynamic temperature measurement, the dynamic characteristics of the sensor affect the accuracy of the measurement results. Thermocouples are widely used for temperature measurement in harsh conditions due to their low cost, robustness, and reliability, but because of the presence of the thermal inertia, there is a dynamic error in the dynamic temperature measurement. In order to eliminate the dynamic error, two-thermocouple sensor was used to measure dynamic gas temperature in constant velocity flow environments in this paper.

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In this paper, we report on the low energy-density recording with a high-repetition-rate femtosecond pulsed beam in homogenous gold-nanorod-dispersed discs by using low numerical aperture (NA) micro-optics. By focusing a femtosecond pulsed beam at a repetition rate of 82 MHz using a low NA DVD optical head, the spatially-stretched energy density introduces a temperature rising of the polymer matrix. This temperature rising facilitates the surface melting of gold nanorods, which leads to over one-order-of-magnitude reduction in the energy-density threshold for recording, compared with that by focusing single pulses through a high NA objective.

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Carboxyamidotrizole (CAI) has been reported to suppress the production of tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β and be effective in rats with adjuvant arthritis. The aim of this study was to investigate the role of CAI in inflammatory bowel disease (IBD). We assessed the effect of CAI in dextran sodium sulfate-induced colitis.

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Background And Purpose: Fangchinoline is a novel anti-tumour agent with little known of its cellular and molecular mechanisms of action. Here we have investigated the mode of cell death induced by fangchinoline and its underlying mechanism in two human hepatocellular carcinoma cell lines, HepG2 and PLC/PRF/5.

Experimental Approach: Apoptosis and autophagy were monitored in fangchinoline-treated HepG2 and PLC/PRF/5 cells by histological methods.

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Objective: To explore the potential anti-inflammatory and analgesic activities of carboxyamidotriazole (CAI).

Methods: A variety of animal models, including the croton oil-induced ear edema, the cotton-induced granuloma, the rat adjuvant-induced arthritis, were used to evaluate anti-inflammatory effect of CAI. Vascular endothelial growth factor (VEGF)--or histamine-stimulated local vascular permeability in mouse modulated by CAI was also determined.

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