- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2019
- 2018
- 2015
- low-temperature electronics
- junction field-effect transistors
- Bessel Function
- Coupling Coefficient
- Fusion temperature and Elongation speed
- Infrared Thermography
- Statistical Analysis
- Mean Temperature Difference
- Surface temperature distribution
- Diabetic Foot Complications
- Optoelectronic Information Science and Engineering
- Electronic Science and Technology
- Physics
- Don State Technical University
- China Jiliang University
- UIN Suska Riau
- BMS College of Engineering
- Dalhousie University
- Majmaah University
- Soochow University
- University of Riau
- Karnataka Institute of Endocrinology and Research (KIER)
- Southern Federal University
-
Optical pyrometry measurement on oxidized Zircaloy-4 cladding
摘要： In order to improve the safety of nuclear power plant, loss-of-coolant accident experiments are implemented in research reactor. In this framework, we develop an optical pyrometry device to measure surface temperature (700-1200°C) of Zircaloy cladding without contact. The whole set-up of the simplified device (under air, without radiation) and the measurement procedure including data treatment based on bichromatic pyrometry are presented, as well as results for various temperature levels. Temperature retrieval based on the hypothesis of emissivity ratio equal to a constant, is scanned over a large wavelength range. A rather constant surface temperature is obtained on the spectral range of measurement, confirming the relevancy of emissivity hypothesis. Differences between this non-contact temperature measurement and a complementary thermocouple temperature measurement are also discussed.
关键词： Zircaloy-4 cladding,bichromatic method,optical pyrometry,emissivity,temperature measurement
更新于2025-09-09 09:28:46
-
First application of the optimal estimation method to retrieve temperature from pure rotational raman scatter lidar measurements
摘要： We present the application of the Optimal Estimation Method (OEM) to retrieve atmospheric temperatures from pure rotational Raman (PRR) backscatter lidar measurements. A forward model (FM) is developed to retrieve temperature and tested using synthetic measurements. The OEM offers many advantages for this analysis, including eliminating the need to determine temperature calibration coefficients.
关键词： forward model,pure rotational Raman,Optimal Estimation Method,Raman lidar,temperature retrieval
更新于2025-09-09 09:28:46
-
Enhancement of the absorption bands in the infrared spectra of low-temperature uracil films by interference
摘要： An experimental method that enables significant enhancement of the bands in the IR absorption spectra of low-temperature films, using standard equipment for matrix isolation, was proposed. The effect is achieved due to the interference amplification of an electromagnetic wave using a sublayer of Ar film. IR Fourier spectra of low-temperature films of uracil (Ur) molecules were obtained in the range of 2000–500 cm–1, with a resolution of 3 cm–1. Thin Ur films with thickness of approximately 0.3 μm were grown at low temperatures on the surface of argon films of thickness of 2.3 and 1.1 μm. An enhancement in the spectral range of 1250–500 cm–1 was recorded for the first bilayer structure, and in the range of 2000–500 cm–1 for the second one. As a result of amplification in the spectrum of the low-temperature uracil film, absorption bands in the range of out-of-plane deformation vibrations of 1000–500 cm–1 were recorded for the first time. It was found that the out-of-plane fundamental NH modes of Ur groups are most sensitive to changes in the crystal structure of the film. It was shown that the absorption spectrum of the Ur film heated to room temperature differs from the spectrum of the Ur crystal obtained from the solution, which indicates a difference in their structures.
关键词： uracil,interference amplification,low-temperature films,absorption bands,infrared spectra
更新于2025-09-09 09:28:46
-
by means of high-pressure–high-temperature Raman experiments
摘要： We report here high-pressure–high-temperature Raman experiments performed on BiVO4. We characterized the fergusonite and scheelite phases (powder and single crystal samples) and the zircon polymorph (nanopowder). The experimental results are supported by ab initio calculations, which, in addition, provide the vibrational patterns. The temperature and pressure behavior of the fergusonite lattice modes reflects the distortions associated with the ferroelastic instability. The linear coefficients of the zircon phase are in sharp contrast to the behavior observed in the fergusonite phase. The boundary of the fergusonite-to-scheelite second-order phase transition is given by TF ?Sch(K) = ?166(8)P (GPa) + 528(5). The zircon-to-scheelite, irreversible, first-order phase transition takes place at TZ?Sch(K) = ?107(8)P (GPa) + 690(10). We found evidence of additional structural changes around 15.7 GPa, which in the downstroke were found to be not reversible. We analyzed the anharmonic contribution to the wave-number shift in fergusonite using an order parameter. The introduction of a critical temperature depending both on temperature and pressure allows for a description of the results of all the experiments in a unified way.
关键词： zircon,scheelite,BiVO4,fergusonite,high-temperature,phase transition,high-pressure,ab initio calculations,Raman experiments,vibrational patterns
更新于2025-09-09 09:28:46
-
Studies on Temperature and Strain Sensitivities of a Few-mode Critical Wavelength Fiber Optic Sensor
摘要： This paper studied the relationship between the temperature/strain wavelength sensitivity of a fiber optic in-line Mach-Zehnder Interferometer (MZI) sensor and the wavelength separation of the measured wavelength to the critical wavelength (CWL) in a CWL-existed interference spectrum formed by interference between LP01 and LP02 modes. The in-line MZI fiber optic sensor has been constructed by splicing a section of specially designed few-mode fiber (FMF), which support LP01 and LP02 modes propagating in the fiber, between two pieces of single mode fiber. The propagation constant difference, Δβ, between the LP01 and LP02 modes, changes non-monotonously with wavelength and reaches a maximum at the CWL. As a result, in sensor operation, peaks on the different sides of the CWL then shift in opposite directions, and the associated temperature/strain sensitivities increase significantly when the measured wavelength points become close to the CWL, from both sides of the CWL. A theoretical analysis carried out has predicted that with this temperature/strain sensor approach, the temperature/strain wavelength sensitivities are governed by the wavelength difference between the measured wavelength and the CWL. This conclusion was seen to agree well with the experimental results obtained. Combining the wavelength shifts of the peaks and the CWL in the transmission spectrum of the SFS structure, this study has shown that this approach forms the basis of effective designs of high sensitivity sensors for multi-parameter detection and offering a large measurement range to satisfy the requirements needed for better industrial measurements.
关键词： few mode fiber,temperature sensitivity,In-line Mach-Zehnder interferometer,strain sensitivity,critical wavelength
更新于2025-09-09 09:28:46
-
[ACM Press the 2nd International Symposium - Stockholm, Sweden (2018.09.21-2018.09.23)] Proceedings of the 2nd International Symposium on Computer Science and Intelligent Control - ISCSIC '18 - Embedded Automatic Control System for Temperature, Humidity and Light Intensity in Agricultural Greenhouses
摘要： Based on the science and technology plan project of Shandong province, this paper designs an automatic control system based on the temperature, humidity and light intensity of the embedded agricultural greenhouse. The system uses DHT11 temperature and humidity sensor and BH1750 light intensity sensor to collect environmental information and transmit the collected data to the STM32F103ZET6 microcontroller for processing and sending out control signals. The system is simple in operation, low in cost and high in precision.
关键词： Temperature and humidity sensor,Light intensity sensor,STM32 microcontroller
更新于2025-09-09 09:28:46
-
Simultaneous Measurement of Air Pressure and Temperature Using Fiber-Optic Cascaded Fabry-Perot Interferometer
摘要： We propose and demonstrate a fiber-optic cascaded-cavity Fabry-Perot interferometer (FPI) for simultaneous measurement of air pressure and temperature. The open-cavity hybrid FPI consists of an air-cavity and a silica-cavity formed by a section of silica tube and photonic crystal fiber (PCF), respectively. The air-cavity and silica-cavity exhibit different sensitivities to air pressure and temperature. Thus, the proposed sensor can be used to implement air pressure and temperature sensing simultaneously. The spectra of the air-cavity and silica-cavity are extracted from the total reflection spectrum with designed band-pass filters. The air pressure and temperature sensitivities of the air-cavity are 4.04 pm/kPa and 0.87 pm/℃, respectively, and those of the silica-cavity are 3.36 pm/kPa and 14.36 pm/℃, respectively. Moreover, the temperature and air pressure cross-sensitivity can be reduced by using a sensitivity coefficients matrix of two cavities. With the advantages of compact size, easy fabrication, and all-fiber structure, the proposed sensor is potential candidate for practical applications.
关键词： Air pressure and temperature measurement,Fabry-Perot interferometer
更新于2025-09-09 09:28:46
-
The Correlation between the Energy Gap and the Pseudogap Temperature in Cuprates: The YCBCZO and LSHCO Case
摘要： The paper analyzes the influence of the hole density, the out-of-plane or in-plane disorder, and the isotopic oxygen mass on the zero temperature energy gap (2Δ(0)) Y1???Ca??Ba2(Cu1???Zn??)3O7??? (YCBCZO) and La1.96???Sr??Ho0.04CuO4 (LSHCO) superconductors. It has been found that the energy gap is visibly correlated with the value of the pseudogap temperature (???). On the other hand, no correlation between 2Δ(0) and the critical temperature (????) has been found. The above results mean that the value of the dimensionless ratio 2Δ(0)/???????? can vary very strongly together with the chemical composition, while the parameter 2Δ(0)/??????? does not change significantly. In the paper, the analytical formula which binds the zero temperature energy gap and the pseudogap temperature has been also presented.
关键词： energy gap,pseudogap temperature,superconductors,cuprates,electron-phonon interaction,electron-electron correlations
更新于2025-09-09 09:28:46
-
EXPERIMENTAL LEVELLING AT THE INTERFACE OF OPTICAL ENVIRONMENTS
摘要： The article discusses the problems of refraction and its impact on levelling at the interface of optical environments. It describes the in?uence of a vertical refraction and shows the results of investigating the e?ect of the refraction in the course of levelling at the interface of optical environments. The results of the experiment were obtained by levelling through the building of the National Technical Library in Prague Dejvice.
关键词： refraction,levelling,temperature gradient,digital thermometer
更新于2025-09-09 09:28:46
-
A 4H-SiC BJT as a Switch for On-chip Integrated UV Photodiode
摘要： This paper presents the design, fabrication and characterization of a 4H-SiC n-p-n bipolar junction transistor as a switch controlling an on-chip integrated p-i-n photodiode. The transistor and photodiode share the same epitaxial layers and topside contacts for each terminal. By connecting the collector of the transistor and the anode of the photodiode, the photo current from the photodiode is switched off at low base voltage (cut-off region of the transistor) and switched on at high base voltage (saturation region of the transistor). The transfer voltage of the circuit decreases as the ambient temperature increases (2 mV/?C). Both the on-state and off-state current of the circuit have a positive temperature coef?cient and the on/off ratio is >80 at temperature ranged from 25 ?C to 400 ?C. It is proposed that the on/off ratio can be increased by ～1000 times by adding a light blocking layer on the transistor to reduce light induced off-state current in the circuit.
关键词： photodiode,switch,BJT,4H-SiC,UV,high temperature
更新于2025-09-08 13:48:38