Linear red/green ratiometric thermometry of Ho3+/Cr3+ co-doped red up-conversion tungstate materials

2021 ◽  
Author(s):  
Yan Zhao ◽  
Xusheng Wang ◽  
Rui Hu ◽  
Yanxia Li
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
High Sensitivity ◽  
Temperature Sensing ◽  
High Temperature Range ◽  
Temperature Range ◽  
Co Doped ◽  
Sensing Performance

Existing optical thermometers are faced with the challenges of high sensitivity limited to a very narrow high temperature range, while also lacking low temperature sensing performance. A new linear up-conversion...

Synthesis, structure and temperature sensing of a lanthanide-organic framework constructed from a pyridine-containing tetracarboxylic acid ligand

CrystEngComm ◽  
2018 ◽  
Vol 20 (45) ◽  
pp. 7395-7400 ◽  
Author(s):  
Dian Zhao ◽  
Huizhen Wang ◽  
Guodong Qian
Keyword(s):  
High Temperature ◽  
Metal Organic Framework ◽  
Temperature Sensing ◽  
Tetracarboxylic Acid ◽  
High Temperature Range ◽  
Temperature Range ◽  
Acid Ligand ◽  
Metal Organic ◽  
Lanthanide Metal ◽  
Organic Framework

A high sensitive, thermostable mixed lanthanide metal–organic framework, Eu0.19Tb0.81PDDI, was developed as a self-calibrated thermometer effective in the high temperature range of 313 to 473 K.

scholarly journals A Study of Isothermal Curing of PMI Using DMA

2015 ◽  
Vol 2015 ◽  
pp. 1-12
Author(s):  
Jing Zhang ◽  
Rui Ye ◽  
Jun Zou ◽  
Jijun Tang ◽  
Hongliang Wang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Nonequilibrium Thermodynamic ◽  
Fluctuation Theory ◽  
Avrami Equation ◽  
High Temperature Range ◽  
Dynamic Mechanical ◽  
Temperature Range ◽  
Thermodynamic Fluctuation ◽  
Relative Conversion

The isothermal curing of polymethacrylimide (PMI) is studied through the use of dynamic mechanical analysis (DMA). Based on the growth rate of measured dynamic mechanical property, the relative conversion is defined to investigate the evolution of storage modulusE′at different curing temperatures. Hsich’s nonequilibrium thermodynamic fluctuation theory, Avrami equation, and isoconversional methods are used to analyze isothermal cure kinetics of PMI. The results show that there are different increase modes ofE′at low temperature range and high temperature range, respectively. In low temperature range, the relative conversion curves include a transitional stage which is found to be strongly frequency-dependent, but this stage is not observed in the relative conversion curve in high temperature range. During the isothermal curing process, the relative evolution ofE′can be described by Hsich’s nonequilibrium thermodynamic fluctuation theory and Avrami equation. Moreover, the values and evolutions of activation energy are different in two temperature ranges, which suggest that the curing mechanism probably has changed.

A study on temperature sensing performance based on the luminescence of Eu3+ and Er3+ co-doped YNbO4

2020 ◽  
Vol 49 (24) ◽  
pp. 8194-8200 ◽  
Author(s):  
Jiashan Mao ◽  
Bin Jiang ◽  
Peng Wang ◽  
Liting Qiu ◽  
Muhammad Tahir Abass ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Solid State Reaction ◽  
Solid State Reaction Method ◽  
Temperature Sensing ◽  
Reaction Method ◽  
Co Doped ◽  
Sensing Performance

Eu3+ and Er3+ co-doped YNbO4 powder phosphors were synthesized by a traditional high-temperature solid-state reaction method.

Fabrication of SnO2–SnO nanocomposites with p–n heterojunctions for the low-temperature sensing of NO2 gas

Nanoscale ◽  
2015 ◽  
Vol 7 (28) ◽  
pp. 12133-12142 ◽  
Author(s):  
Lei Li ◽  
Chunmei Zhang ◽  
Wei Chen
Keyword(s):  
Low Temperature ◽  
High Sensitivity ◽  
Temperature Sensing ◽  
Gas Detection ◽  
Hybrid Nanostructure ◽  
Sensitivity And Selectivity ◽  
Sensing Performance

A SnO2–SnO hybrid nanostructure with p–n heterojunctions exhibits enhanced sensing performance for NO2 gas detection with high sensitivity and selectivity.

Analysis of Temperature Characteristics of an AlGaAs/GaAs/Ge Triple-Junction Solar Cell by IS

2013 ◽  
Vol 756-759 ◽  
pp. 101-104
Author(s):  
Yi Qing Zhang ◽  
Wen Jun Cao ◽  
Ai Min Liu
Keyword(s):  
Solar Cell ◽  
High Temperature ◽  
Impedance Spectroscopy ◽  
Low Temperature ◽  
Equivalent Circuit ◽  
Triple Junction ◽  
Temperature Characteristics ◽  
High Temperature Range ◽  
Temperature Range ◽  
Junction Solar Cell

Composition of an AlGaAs/GaAs/Ge triple-junction solar cell were analyzed using an equivalent circuit. The currentvoltage (IV) characteristics and impedance spectroscopy (IS) of it were measured in the temperature range from 20°C to 180°C. In the high-temperature range (from 140°C to 200°C) the VOCchanges faster than those in the low-temperature range (from 20°C to 80°C).This is because contribution of the VOCfrom the Ge subcell becomes nearly zero in the high temperature. R and C of the bottom subcell keep almost the same in the high temperature.

Activation Energy for Recrystallization in Fe-3wt.%Si Alloys with Different S Contents

2013 ◽  
Vol 753 ◽  
pp. 181-184 ◽  
Author(s):  
Wei Min Mao ◽  
Mao Hua Zhang ◽  
Ping Yang ◽  
Kai Ping Wang
Keyword(s):  
Activation Energy ◽  
High Temperature ◽  
Low Temperature ◽  
Boundary Migration ◽  
Mechanical Calculation ◽  
High Temperature Range ◽  
Temperature Range ◽  
Cottrell Atmosphere

The recrystallization behaviors of 60% rolled Fe-wt.3%Si and Fe- wt.3%Si-Mn-S alloys containing coarsen MnS particles were observed in temperature range 600°C~1000°C. The activation energy for recrystallization was determined according to an Arrhenius type of relationship. It was found that the activation energy in the temperature range 600°C~750°C was much higher than that in the temperature range 850°C~1000°C. Thermo-mechanical calculation indicates that there are hardly precipitation behaviors of MnS particles in 600°C~1000°C. Fe3C will precipitate below 650°C and Cottrell atmosphere will form just above 650°C, which induces dragging effect against the boundary migration during recrystallization and increase the activation energy. The activation energy determined was about 99kJ/mol or 217kJ/mol in Fe-3%Si alloy and 91kJ/mol or 220kJ/mol in Fe-3%Si-Mn-S alloy for the recrystallization in high temperature range of 850°C~1000°C or low temperature range of 600°C~750°C respectively.

scholarly journals High-Temperature Deformation of Naturally Aged 7010 Aluminum Alloy

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 581
Author(s):  
Abdulhakim A. Almajid
Keyword(s):  
Activation Energy ◽  
Aluminum Alloy ◽  
High Temperature ◽  
Threshold Stress ◽  
Activation Energies ◽  
Temperature Deformation ◽  
High Temperature Range ◽  
Temperature Range ◽  
True Activation Energy ◽  
Two Temperatures

This study is focused on the deformation mechanism and behavior of naturally aged 7010 aluminum alloy at elevated temperatures. The specimens were naturally aged for 60 days to reach a saturated hardness state. High-temperature tensile tests for the naturally aged sample were conducted at different temperatures of 573, 623, 673, and 723 K at various strain rates ranging from 5 × 10−5 to 10−2 s−1. The dependency of stress on the strain rate showed a stress exponent, n, of ~6.5 for the low two temperatures and ~4.5 for the high two temperatures. The apparent activation energies of 290 and 165 kJ/mol are observed at the low, and high-temperature range, respectively. These values of activation energies are greater than those of solute/solvent self-diffusion. The stress exponents, n, and activation energy observed are rather high and this indicates the presence of threshold stress. This behavior occurred as a result of the dislocation interaction with the second phase particles that are existed in the alloy at the testing temperatures. The threshold stress decreases in an exponential manner as temperature increases. The true activation energy was computed by incorporating the threshold stress in the power-law relation between the stress and the strain. The magnitude of the true activation energy, Qt dropped to 234 and 102 kJ/mol at the low and high-temperature range, respectively. These values are close to that of diffusion of Zinc in Aluminum and diffusion of Magnesium in Aluminum, respectively. The Zener–Hollomon parameter for the alloy was developed as a function of effective stress. The data in each region (low and high-temperature region) coalescence in a segment line in each region.

Oxygen Precipitation in Conventional and Nitrogen Co-Doped Heavily Arsenic-Doped Czochralski Silicon Crystals: Oswald Ripening

2009 ◽  
Vol 156-158 ◽  
pp. 275-278
Author(s):  
Xiang Yang Ma ◽  
Yan Feng ◽  
Yu Heng Zeng ◽  
De Ren Yang
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Czochralski Silicon ◽  
Silicon Crystals ◽  
Oxygen Precipitation ◽  
High Temperature Anneal ◽  
Oxygen Precipitates ◽  
Co Doped ◽  
Oswald Ripening

Oxygen precipitation (OP) behaviors in conventional and nitrogen co-doped heavily arsenic-doped Czocharalski silicon crystals subjected to low-high two-step anneals of 650 oC/8 h + 1000 oC/4-256 h have been comparatively investigated. Due to the nitrogen enhanced nucleation of OP during the low temperature anneal, much higher density of oxygen precipitates generated in the nitrogen co-doped specimens. With the extension of high temperature anneal, Oswald ripening of OP in the nitrogen co-doped specimens preceded that in the conventional ones. Moreover, due to the Oswald ripening effect, the oxygen precipitates in the conventional specimens became larger with a wider range of sizes. While, the sizes of oxygen precipitates in the nitrogen co-doped specimens distributed in a much narrower range with respect to the conventional ones.

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