修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

过滤筛选

出版时间
  • 2019
  • 2018
  • 2015
研究主题
  • 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
应用领域
  • Optoelectronic Information Science and Engineering
  • Electronic Science and Technology
  • Physics
机构单位
  • 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
1238 条数据
?? 中文（中国） ▾

  • Study of the Effect of Ni additive in YBa2Cu3O7-δ Superconducting Composite Employing Ultrasonic Measurement

    摘要： A series of superconducting composites (100-x) YBa2Cu3O7-δ + x Ni metal (x = 0, 1, 2.5, 5, 7.5, 10 and 15 wt.%) was prepared by the solid state reaction method. Density and molar volume were determined using the immersion method. X-Rays-Diffraction (XRD) and Scanning Electron Microscope (SEM) characterizations were terminated for structural and microstructural analysis. The results showed the presence of orthorhombic peaks of YBa2Cu3O7-δ (YBCO) in the whole composite samples with different lattice constants and how Ni addition affects the distortions in the orthorhombic unit cell of YBCO. A new technique has been used to measure the ultrasonic wave velocities, longitudinal (VL) and transverse or shear (VS), at 4 MHz ultrasonic frequency at room temperature. The mechanical parameters of the sintered superconductor samples including longitudinal modulus (L), shear modulus (G), Young’s modulus (Y), Poisson’s ratio (σ) and microhardness (H) were investigated from the view point of the porosity and the connectivity between the formed phases. Besides, the Debye temperature (?D) was also determined as a function of Ni additions. The elastic moduli, H and ?D have been improved up to 2.5 wt.% Ni, then a decrease in all data observed with further addition of Ni content. Quantitative analysis has been implemented to obtain more details about the structure of the composite samples, based on orthorhombic phases, the oriented grain size, the porosity and the agglomeration between grains.

    关键词： Debye temperature,ultrasonic velocity,porosity,elastic moduli,microhardness

    更新于2025-09-04 15:30:14

  • [IEEE 2018 33rd Symposium on Microelectronics Technology and Devices (SBMicro) - Bento Gon?alves, Brazil (2018.8.27-2018.8.31)] 2018 33rd Symposium on Microelectronics Technology and Devices (SBMicro) - Non uniformity correction in a Long Wave Infrared Focal Plane Array as a function of the higher calibration temperature

    摘要： It is well known that every detector in a Focal Plane Array (FPA) has a different responsivity and offset. These variations result in a specific kind of noise, the Fixed Pattern Noise (FPN) or spatial noise. During the image processing, those pixels who has a large deviation in responsivity are considered a bad pixel, and has its value removed of FPA. Knowing the answer of in a FPA all those pixels are the first test procedure characterization. However, during the bad pixels analysis it is necessary to choose two reference temperatures, calibration points, and those temperature affects important parameters such as Uniformity, Noise Equivalent Temperature Difference (NETD) and Signal Transfer Function (SiTF). This work will study the influence of higher calibration temperature on the Non-Uniformity Correction (NUC) quality.

    关键词： Focal Plane Array,Uniformity,Signal Transfer Function,Noise Equivalent Temperature Difference,Long Wave Infrared

    更新于2025-09-04 15:30:14

  • Temperature-independent refractive index sensor based on fiber Bragg grating and spherical-shape structure

    摘要： A fiber-optic refractive index (RI) sensor consisting of a fiber Bragg grating (FBG) spliced in downstream of a spherical-shape structure in a single-mode fiber (SMF) is proposed and experimentally demonstrated. The cladding modes with different effective refractive indices can be efficiently excited by the spherical-shape structure. By measuring the difference of the wavelength shifts between the reflected cladding Bragg mode and the core mode, we have achieved a maximum sensitivity of 2.87 nm/RIU with range of the RI from 1.357 to 1.458. When the temperature changes from 25 °C to 225 °C, the relative wavelength shift between the cladding mode and the core mode has no significant changes, which indicates that this fiber-optic sensor allows for temperature-independent RI measurement.

    关键词： Refractive index sensor,Temperature-independent,Spherical-shape structure,Fiber Bragg grating

    更新于2025-09-04 15:30:14

  • Cavity-enhanced absorption sensor for carbon monoxide in a rapid compression machine

    摘要： A sensor based on cavity-enhanced absorption spectroscopy (CEAS) was implemented for the first time in a rapid compression machine (RCM) for carbon monoxide concentration measurements. The sensor consisted of a pulsed quantum cascade laser (QCL) coupled to a low-finesse cavity in the RCM using an off-axis alignment. The QCL was tuned near 4.89 μm to probe the P(23) ro-vibrational line of CO. The pulsed mode operation resulted in rapid frequency down-chirp (6.52 cm ?1 / μs) within the pulse as well as a high time resolution (10 μs). The combination of rapid frequency down-chirp and off-axis cavity alignment enabled a near complete suppression of the cavity coupling noise. A CEAS gain factor of 133 was demonstrated in experiments, resulting in a much lower noise-equivalent detection limit than a single-pass arrangement. The sensor thus presents many opportunities for measuring CO formation at low temperatures and for studying kinetics using dilute reactive environments; one such application is demonstrated in this work using dilute n-heptane/air mixtures in the RCM. The formation of CO during first-stage ignition of n-heptane was measured over 802–899 K at a nominal pressure of 10 bar. These conditions correspond to the NTC region of n-heptane and such results provide useful metrics to test and compare the predictions of low-temperature heat release by different kinetic models.

    关键词： n-heptane,Low-temperature heat release,Cavity-enhanced absorption spectroscopy,Rapid compression machine,Carbon monoxide

    更新于2025-09-04 15:30:14

  • Low-Temperature Process for Direct Formation of MoS2 Thin Films on Soda-Lime Glass Substrates

    摘要： To obtain molybdenum disulfide (MoS2) patterns without any mechanical problems caused by the transfer process, direct current (DC) sputtering and rapid thermal processing (RTP) were used to form MoS2 instead of the conventional chemical vapor deposition (CVD) process. To form MoS2 on a soda-lime glass substrate at temperatures below 600 °C, MoS2 films were deposited at various DC sputtering powers and annealed at various temperatures from 400 °C to 550 °C. From the scanning electron microscope (SEM) and atomic force microscope (AFM) results, the surface morphologies of the MoS2 films can be observed, depending on the sputtering power and the film thickness. The Raman spectrum results showed that the E1 2g and A1 g mode peaks appeared at approximately 372 cm?1 and 400 cm?1, respectively, and the MoS2 surface was crystallized in the in-plane direction. The X-ray photoelectron spectroscopy (XPS) results showed noticeable S 2p (2p 1/2, 2p 3/2) peaks and Mo 3d (3d 3/2, 3d 5/2) peaks at stable binding energies after RTP at temperatures below 600 °C. The high mobilities and carrier densities of all the MoS2 films can be investigated from the Hall measurements.

    关键词： DC Sputtering,Low Temperature,Molybdenum Disulfide (MoS2),Rapid Thermal Processing (RTP),Soda-Lime Glass

    更新于2025-09-04 15:30:14

  • Significant improvement of the performance of ZrO2/V1-W O2/ZrO2 thermochromic coatings by utilizing a second-order interference

    摘要： The paper deals with VO2-based thermochromic coatings prepared by reactive magnetron sputtering. We combine four ways how to improve the coating performance and to increase its application potential. First, reactive high-power impulse magnetron sputtering with a pulsed O2 flow control allowed us to prepare crystalline VO2 of the correct stoichiometry under highly industry-friendly deposition conditions: without any substrate bias at a low deposition temperature of 330 °C. Second, doping of VO2 by W (leading to V1-xWxO2, with x = 0.012 in this work) allowed us to shift the thermochromic transition temperature towards the room temperature (39 °C in this work), without concessions in terms of coating properties. Third, we employ ZrO2 antireflection layers both below and above the thermochromic V1-xWxO2 layer, and present an optimum design of the resulting ZrO2/V1-xWxO2/ZrO2 coatings. Most importantly, we show that while utilizing a first-order interference on ZrO2 leads one to a tradeoff between the luminous transmittance (Tlum) and the modulation of the solar transmittance (ΔTsol), utilizing a second-order interference allows one to optimize both Tlum and ΔTsol in parallel. Fourth, the crystalline structure of the bottom ZrO2 layer further improves the VO2 crystallinity and the process reproducibility. The optimum experimental values of ZrO2 thickness are in agreement with those predicted during the coating design. The results are important for the design and low-temperature fabrication of high-performance durable thermochromic VO2-based coatings for smart window applications.

    关键词： Thermochromic coatings,Low deposition temperature,Antireflection layer,HiPIMS,Doping,VO2

    更新于2025-09-04 15:30:14

  • Total Global Solar Radiation Estimation with Relative Humidity and Air Temperature Extremes in Ireland and Holland

    摘要： Solar radiation is the earth’s primary energy source for all biochemical and physical activities. Accurate knowledge of the solar radiation is important in engineering applications. This study aimed to calibrate some of the existing models in the literature for estimating daily total global solar radiation parameter using available measuring records (maximum and minimum air temperatures) and new models were developed based on maximum and minimum air temperatures, relative humidity and relative humidity extremes. Applicability of the Hargreaves model, Allen model, Bristow-Campbell model and Chen model were evaluated for computing the daily total solar global radiation, the geographical and meteorological data of Irish and Dutch cities were used. Meteorological data were taken from Royal Netherlands Meteorological Institute and Irish Meteorological Service. The models were compared on the basis of error tests which were mean percentage error (MPE), mean bias error (MBE), root mean square error (RMSE) and Nash-Sutcliffe equation (NSE). And, monthly MPE errors were given for each model. This study proposed new estimation models which were based on daily average relative humidity, relative humidity extremes and temperature extremes. Error analyses were applied to these models and results were given in the study.

    关键词： Holland,solar radiation,model validation,temperature,daily total global solar radiation,relative humidity,model comparison,Ireland,meteorological models

    更新于2025-09-04 15:30:14

  • Fabrication of vertical alignment liquid crystal cell without forming a conventional polyimide-alignment layer

    摘要： A novel preparation method of the vertical alignment polymer film (VAPF) was proposed by polymerisation of the monomers, 2,3-difluoro-4?-[2-(diacryloyl-oxy-hexyl)methyl ester-hexadecyl-oxy]-biphenyl (DFDAMHB) and 2,7-dimethacryloyl-oxy-phenanthrene (DMAPhen), being dissolved in the liquid crystal (LC) material. For obtaining the vertical alignment (VA), the ultraviolet exposure was carried out to the LC cell below the nematic to isotropic transition temperature of the LC material. The VA mode LC cell with the VAPF produced from the monomers DFDAMHB and DMAPhen exhibited enough level of electro-optical and response properties, high voltage holding ratio and low residual direct current voltage.

    关键词： vertical alignment polymer film,Liquid crystals,nematic to isotropic transition temperature,monomers,polymerisation

    更新于2025-09-04 15:30:14

  • [IEEE 2018 14th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT) - Qingdao, China (2018.10.31-2018.11.3)] 2018 14th IEEE International Conference on Solid-State and Integrated Circuit Technology (ICSICT) - Simulation of a Novel Integrated 4H-SiC Temperature Sensor

    摘要： This paper presents a novel integrated Schottky barrier diode temperature sensor in a 4H-SiC power MOSFET. Dual electrical isolation and additional current path are applied to this temperature sensor, allowing the sensor to work properly in any operating state of power MOSFET. Due to the sufficient electrical isolation, the crosstalk between sensor and power MOSFET is almost eliminated. Furthermore, high sensitivity S=1.21mV/K is observed for a constant bias current of Id=1mA. The temperature sensor exhibits a good degree of linearity with a root mean square error R2=0.99996.

    关键词： Temperature sensor,4H-SiC,Power MOSFET,Self-heating,Crosstalk

    更新于2025-09-04 15:30:14

  • Simultaneous measurement of refractive index and temperature based on a long period fiber grating inscribed in a photonic crystal fiber with an electric-arc discharge

    摘要： A novel fiber sensor composed by two single mode fibers and long period fiber grating based on a photonic crystal fiber prepared by periodic discharge heating has been experimentally investigated to measure refractive index and temperature. A Mach-Zehnder interferometer was formed due to the presence of two fusion spliced collapsed regions in the photonic crystal fiber. The resonance dip and interference pattern were differently influenced by the ambient disturbance, so the dual-parameters were simultaneously measured by analyzing the characteristics of transmission spectrum. After the experimental measurements, refractive index and temperature sensitivities of 117.28 nm/RIU and (cid:1)86.29 pm/(cid:3)C were realized. Therefore, the reported sensor with advantages of easy fabrication, simple structure, and small size has the potential for simultaneous refractive index and temperature measurements involving biochemical sensing applications.

    关键词： simultaneous measurement,photonic crystal fiber,refractive index and temperature,Long period fiber grating

    更新于2025-09-04 15:30:14