scholarly journals Research of Fluorescent Properties of a New Type of Phosphor with Mn2+-Doped Ca2SiO4

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2788
Author(s):  
Xiaozhou Fan ◽  
Wenqi Zhang ◽  
Fangcheng Lü ◽  
Yueyi Sui ◽  
Jiaxue Wang ◽  
...  
Keyword(s):  
Electromagnetic Interference ◽  
Green Emission ◽  
Response Speed ◽  
Sintered Sample ◽  
Solid State Reaction Method ◽  
Average Lifetime ◽  
Diffraction Spectrum ◽  
Fluorescent Properties ◽  
Fluorescent Material ◽  
New Type

Fluorescent optical fiber temperature sensors have attracted extensive attention due to their strong anti-electromagnetic interference ability, good high-voltage insulation performance, and fast response speed. The fluorescent material of the sensor probe directly determines the temperature measurement effect. In this paper, a new type of fluorescent material with a Mn2+-doped Ca2SiO4 phosphor (CSO:Mn2+) is synthesized via the solid-state reaction method at 1450 °C. The X-ray diffraction spectrum shows that the sintered sample has a pure phase structure, although the diffraction peaks show a slight shift when dopants are added. The temperature dependence of the fluorescence intensity and lifetime in the range from 290 to 450 K is explored with the help of a fluorescence spectrometer. Green emission bands peaking at 475 and 550 nm from Mn2+ are observed in the fluorescence spectra, and the intensity of emitted light decreases as the temperature rises. The average lifetime of CSO:Mn2+ is 17 ms, which is much higher than the commonly used fluorescent materials on the market. The fluorescence lifetime decreases with increasing temperature and shows a good linear relationship within a certain temperature range. The research results are of great significance to the development of a new generation of fluorescence sensors.

Temperature Dependence on Dielectric Response of La0.7Ba0.3Mn0.4Ti0.6O3 Ceramic

2015 ◽  
Vol 1107 ◽  
pp. 45-52
Author(s):  
Aaliyawani Ezzerin Sinin ◽  
Walter Charles Primus ◽  
Abdul Halim Shaari ◽  
Zainal Abidin Talib ◽  
Sinin Hamdan
Keyword(s):  
Dielectric Properties ◽  
Temperature Dependence ◽  
Low Frequency ◽  
Sintered Sample ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Low Frequencies ◽  
X Ray ◽  
Lcr Meter

Ceramic sample of La0.70Ba0.30Mn0.40Ti0.60O3 oxide has been prepared by the conventional solid-state reaction method. The sintered sample was characterized by using x-ray diffraction (XRD) and low frequency LCR meter. XRD result shows that the sample has a cubic structure with the existence of impurity phase. The dielectric properties of La0.70Ba0.30Mn0.40Ti0.60O3 measured from room temperature to 200°C shows that the dielectric permittivity is temperature dependence with strong dispersion at low frequencies. A circuit model based on the universal capacitor response function is also being used to represent the dielectric properties of the sample.

Study of the Squeeze Film Damper of Larger Flow Rate High-Speed On/Off Valve

2011 ◽  
Vol 130-134 ◽  
pp. 594-598
Author(s):  
Hai Bing Jiang ◽  
Jian Ruan ◽  
Ming Ming Wu ◽  
Tao Wang
Keyword(s):  
Flow Rate ◽  
High Speed ◽  
Response Speed ◽  
Fast Response ◽  
Squeeze Film ◽  
Squeeze Film Damper ◽  
Perfect Performance ◽  
Sealing Performance ◽  
New Type ◽  
Off Time

A new type of squeeze film damper (SFD) is designed to reduce spool’s impact and vibration which happen in the two-stage larger flow rate high-speed on/off valve with the 450 L/min flow rate and 8ms turn-off time, the valve’s sealing performance、reliability and service life improve largely, and the valve’s response speed doesn’t drop. The simulated and experimental results show: The damper has optimum buffering performance when oil film thickness is 0.1mm, and the spool closing process approach ideal state. The valve will has a great potential application in the powerful occasions because of it's perfect performance: larger flow rate、fast response and novel damper.

scholarly journals Bi3+ Effects on Down-/up-conversion Luminescence, Temperature Sensing and Optical Transition Properties in Bi3+/Er3+ Co-doped YNbO4  Phosphors

2020 ◽  
Author(s):  
Xin Wang ◽  
Xiangping Li ◽  
Hongquan Yu ◽  
Sai Xu ◽  
Jiashi Sun ◽  
...  
Keyword(s):  
Near Infrared ◽  
Optical Transition ◽  
Green Emission ◽  
Radiative Transition ◽  
Solid State Reaction Method ◽  
Temperature Sensing ◽  
Infrared Light ◽  
Luminescence Spectra ◽  
Experimental Values ◽  
Co Doped

Abstract A series of Bi3+ single-doped and Bi3+/Er3+ co-doped YNbO4 phosphors with various concentrations of Bi3+ ions were prepared by a conventional high temperature solid-state reaction method. The results of XRD and Rietveld refinement confirmed that monoclinic phase YNbO4 samples were achieved. The down-/up-conversion luminescence of Er3+ ions were investigated under the excitation of ultraviolet light (327 nm) and near infrared light (980 nm). Under 327 nm excitation, broad visible emission band from Bi3+ ions and characteristic green emission peaks from Er3+ ions were simultaneously observed, while only strong green emissions from Er3+ ions were detected upon excitation of 980 nm. Remarkable emission enhancement was observed in down-/up-conversion luminescence processes by introducing Bi3+ ions into Er3+-doped YNbO4 phosphors. By analyzing the laser working current dependent up-conversion luminescence spectra, two-photon processes were confirmed to be responsible for both the green and the red up-conversion emissions of Er3+ ion. The temperature sensing property of Er3+ was studied by using the temperature dependent up-conversion luminescence spectra and it was found that the temperature sensitivity was sensitive to the doping concentration of Bi3+ ions. By comparing the experimental values of the radiative transition rate ratio of the two green emission levels of Er3+ ions and the theoretical values calculated by Judd-Ofelt (J-O) theory, it was concluded that energy level splitting had significant influences on the temperature sensing property of Er3+ ions.

scholarly journals Polyester Fabric With Fluorescent Properties Using Microwave Technology For Anti-Counterfeiting Applications

2021 ◽  
Author(s):  
Fredj Saad ◽  
Ayda Baffoun ◽  
Boris Mahltig ◽  
Mohamed Hamdaoui
Keyword(s):  
Uv Light ◽  
Ultra Violet ◽  
Green Emission ◽  
Polyester Fabric ◽  
Fluorescent Properties ◽  
Microwave Technology ◽  
Uv Absorber ◽  
Yellow Coloration ◽  
Transmission Measurements ◽  
Light Resistance

Abstract The article presented concerns the application of fluorescein as a fluorescent material for anti-counterfeiting technology which will allow the labeling and identification of legitimate articles in the textile field. Fluorescein has been applied to polyester fabrics by microwave irradiation technique in the presence of a UV absorber. Thus, its presence in the textile substrate is detectable following an excitation at a specific wavelength belonging to the Ultra-violet zone, which makes this material very effective for tracking and detecting counterfeit articles. Fluorescent samples are characterized morphologically by scanning electron microscopy (SEM) and quantitatively by optical spectroscopy such as reflectance and transmission measurements. The treated samples show under UV light a yellowish green emission with a slight yellow coloration of the polyester fiber. The UV absorber applied to the fluorescent solution improves the light resistance of the treated samples by 25%. Their addition to the bath can also ensure the production of a protective fabric against UV.

scholarly journals A Time-Overlapping Multiplex VLC System for End-Edge Data Transmission

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Tingting Fu ◽  
Huanghong Zhu ◽  
Han Hai ◽  
Haksrun Lao
Keyword(s):  
Data Transmission ◽  
Electromagnetic Interference ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Transmission Rate ◽  
Pulse Amplitude ◽  
Visible Light Communication ◽  
Radio Communications ◽  
Environmental Light ◽  
New Type

Communication is one of the most important foundations in the Internet of Things. Although some cutting-edge technologies, such as 5G, have greatly empowered edge computing, electromagnetic interference and pollution make them impracticable in many environments. The visible light communication (VLC) is a new type of wireless communication technology with appealing benefits not presented in radio communications. VLC allows a lamp or other light source to not only serve as illumination but also simultaneously transmit data. Although traditional VLC multiplexing technologies have been able to achieve a high-speed data transmission rate, they require all receivers to use the same modulation means. In many scenarios, various-type receivers coexist; it is costly to incorporate multiple senders to implement adaptive content distribution in on-demand services. In this paper, we propose a new type of VLC multiplexing system, which realizes end-edge data transmission through pulse position modulation (PPM), pulse width modulation (PWM), and pulse amplitude modulation (PAM) simultaneously. Therefore, one edge server can serve multiple types of end-users without interference. In order to evaluate the performance of the system, we conduct experiments with different settings of communication distance, communication angle, and different environmental light conditions. For three modulations, the proposed system can achieve a transmission speed three times as that for a single modulation, and reach the accuracy rate of up to 99% within the proper communication range.

Förster energy transfer in cholesteric mixtures: a new type of phototunable fluorescent material

2006 ◽  
Vol 33 (8) ◽  
pp. 907-912 ◽  
Author(s):  
Alexey Bobrovsky ◽  
Valery Shibaev ◽  
Joachim Wendorff
Keyword(s):  
Energy Transfer ◽  
Fluorescent Material ◽  
Förster Energy Transfer ◽  
New Type

Design in Laboratory Equipment for Power Generate and Supply System of New Type Self-Propelled Gun

2014 ◽  
Vol 543-547 ◽  
pp. 541-546
Author(s):  
Xue Bing Liao ◽  
Hong Fei Luo ◽  
Lei Peng ◽  
Feng Ling
Keyword(s):  
Distributed Control ◽  
Electromagnetic Interference ◽  
Supply System ◽  
Control Technique ◽  
Dual Model ◽  
Laboratory Equipment ◽  
Technical Requirements ◽  
Power Generate ◽  
Model Control ◽  
New Type

In order to test new type self-propelled Gun's power generate and supply system, based on modular structure and distributed control design method, using variable frequency control and dual-model control technique, the laboratory equipment was designed according to the technical requirements. Firstly, the structure of the laboratory equipment was build. Based on design of hybrid multimode synchronous teeth belt transmission, programmable load unit, programmable power source and data fusion operator, main composition of the laboratory equipment are developed. Distributed control is used to ensure the laboratory equipment work orderly. To improve ability of anti-electromagnetic interference, three methods are used. Practically use, the synthetically laboratory equipment is proved to being high stability, strong comprehensiveness, good generality.

A New Type of Accelerometer Based on Fiber Bragg Grating

2014 ◽  
Vol 551 ◽  
pp. 210-213
Author(s):  
De Quan Feng ◽  
Xue Guang Qiao ◽  
Min Shao ◽  
Xiao Dong Luo ◽  
Wei Fan
Keyword(s):  
Fiber Bragg Grating ◽  
Electromagnetic Interference ◽  
Mechanical Model ◽  
High Accuracy ◽  
Bragg Grating ◽  
Single Degree Of Freedom ◽  
Single Degree ◽  
High Durability ◽  
New Type ◽  
Excellent Stability

Fiber Bragg Grating has advantages of high resistance to electromagnetic interference and high accuracy, which could obtain high-precision detection of the vibrations. A new type of accelerometer based on Fiber Bragg Grating (FBG) is proposed in this paper. The mechanical model of the accelerometer is designed as a single-degree-of-freedom system. The experiments show FBG accelerometer system has excellent stability and high durability. The acceleration sensitivity of the FBG accelerometer is 31.2pm/G.

scholarly journals Proton, UV, and X-ray Induced Luminescence in Tb3+ Doped LuGd2Ga2Al3O12 Phosphors

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 844
Author(s):  
U. Fawad ◽  
H. J. Kim ◽  
Ibrahim Gul ◽  
Matiullah Khan ◽  
Sajjad Tahir ◽  
...  
Keyword(s):  
Green Emission ◽  
Solid State Reaction Method ◽  
Structural Morphology ◽  
Green Phosphor ◽  
Light Emitting ◽  
X Ray ◽  
Blue Region ◽  
X Ray Imaging ◽  
Plasma Display ◽  
Cie Chromaticity

The well-known solid-state reaction method is used for the synthesis of Tb doped LuGd2Ga2Al3O12 phosphor. XRD and SEM techniques are used for the phase and structural morphology of the synthesized phosphor. UV, X-ray and proton induced spectroscopy is used to study the luminescence properties. LuGd2Ga2Al3O12:Tb3+ phosphor shows its highest peak in green and blue region. The two major emission peaks correspond to 5D3→7FJ (at 480 to 510 nm, blue region) and 5D4→7FJ (at 535 to 565 nm, green region). Green emission is dominant; therefore, it may be used as an efficient green phosphor. The absorption spectra of the synthesized material matches well with the spectra of light emitting diodes (LEDs); therefore, it may have applications in LEDs. X-ray spectroscopic study suggests that this phosphor may have uses in medical applications, such as X-ray imaging. The synthesized phosphor exhibits 81% efficacy in comparison to the commercial plasma display panel material (Gd2O2S:Tb3+). The Commission Internationale de l’Eclairage (CIE) chromaticity diagram is obtained for this phosphor. The decay time of ms range is measured for the synthesized phosphor.

Metal-Free White Light-Emitting Fluorescent Material Based on Simple Pillar[5]arene-tripodal Amide System and Theoretical Insights on Its Assembly and Fluorescent Properties

Langmuir ◽  
2020 ◽  
Vol 36 (45) ◽  
pp. 13469-13476
Author(s):  
Hai-Long Yang ◽  
Zhao-Hui Li ◽  
Pei-Pei Liu ◽  
Xiao-Wen Sun ◽  
Zhong-Hui Wang ◽  
...  
Keyword(s):  
White Light ◽  
Fluorescent Properties ◽  
Light Emitting ◽  
Fluorescent Material ◽  
Metal Free
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