Ground-state conformers enable bright single-fluorophore ratiometric thermometers with positive temperature coefficients

2017 ◽  
Vol 1 (11) ◽  
pp. 2383-2390 ◽  
Author(s):  
Weijie Chi ◽  
Wenting Yin ◽  
Qingkai Qi ◽  
Qinglong Qiao ◽  
Yuyan Lin ◽  
...  
Keyword(s):  
Ground State ◽  
Temperature Sensing ◽  
Positive Temperature ◽  
Temperature Coefficients ◽  
Multiple Conformers

A pseudo-rigid fluorophore with multiple conformers enables highly reliable single-fluorophore ratiometric temperature sensing.

Anomalous Temperature Dependence of the 127I Quadrupole Interaction in Tetraethylstiboniummetaperiodate (C2H5)4SbIO4

1987 ◽  
Vol 42 (3) ◽  
pp. 275-278 ◽  
Author(s):  
Dagmar G. Klobasa ◽  
Paul K. Burkert
Keyword(s):  
Solid State Nmr ◽  
Coupling Constants ◽  
Positive Temperature ◽  
Anomalous Temperature Dependence ◽  
Continuous Change ◽  
Nmr Studies ◽  
Anomalous Temperature ◽  
Gradient Tensor ◽  
Temperature Coefficients ◽  
Quadrupole Coupling

127I solid state NMR studies revealed second order quadrupole effects in (C2H5)4SbIO4 with anomalous positive temperature coefficients of the quadrupole coupling constants. This anomaly is caused by a continuous change of the axes of the electric field gradient tensor.

Improvement on Temperature-Sensing Property of Low-Density Polyethylene Based PTC Composites with Static Magnetic Field Treatment

2011 ◽  
Vol 393-395 ◽  
pp. 139-143
Author(s):  
Bao Zhong Han ◽  
Feng Lian Ma ◽  
Chang Ming Li
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Nickel Powder ◽  
Positive Temperature Coefficient ◽  
Temperature Sensing ◽  
Low Density Polyethylene ◽  
Room Temperature Resistivity ◽  
Low Density ◽  
Positive Temperature ◽  
Magnetic Field Treatment

A stable magnetic field was applied during hot press molding of low-density polyethylene (LDPE)/carbon black (CB)/ carbon nanotube (CNT) composites and HDPE/CB/nickel powder composites. The effect of magnetic field treatment on the temperature-sensing property of LDPE-based positive temperature coefficient (PTC) composites was investigated. Experimental results indicate that the magnetic field treatment can lead to an alignment of CNT and nickel powder in LDPE along the direction of the applied external magnetic field. The alignment of these filler particles can endow the composites with low room-temperature resistivity and high PTC intensity when the concentration of CB is decreased. The alignment also can significantly improve mechanical property and processability of the composites. Compared with CNT, nickel powder with strong magnetism has more sensitive response to external magnetic field and is much easier to align in LDPE. Addition of nickel powder is beneficial for developing PTC composites with excellent comprehensive properties.

Positive temperature coefficients of remanence and coercivity in precipitation-hardened Gd–Co–Fe–Cu–Zr alloys

2004 ◽  
Vol 279 (2-3) ◽  
pp. 143-148 ◽  
Author(s):  
Chuan-bing Rong ◽  
Jian Zhang ◽  
Hong-wei Zhang ◽  
Xiao-bo Du ◽  
Shao-ying Zhang ◽  
...  
Keyword(s):  
Positive Temperature ◽  
Temperature Coefficients ◽  
Zr Alloys

Fabrication of (Ba,Pb)TiO3-based tapes with positive temperature coefficients of resistivity by the oxidation of malleable, metal-bearing precursors (the volume identical metal oxidation process)

1999 ◽  
Vol 14 (11) ◽  
pp. 4319-4328 ◽  
Author(s):  
Seyed M. Allameh ◽  
Kenneth H. Sandhage
Keyword(s):  
Oxidation Process ◽  
Cold Drawing ◽  
High Energy ◽  
Positive Temperature Coefficient ◽  
Thermal Treatments ◽  
Positive Temperature ◽  
Metal Oxidation ◽  
Powder Mixtures ◽  
Temperature Coefficients ◽  
Temperature Coefficient Of Resistivity

The feasibility of producing (Ba,Pb)TiO3-based thermistor tapes by the oxidation of malleable, metal-bearing precursors has been demonstrated. Intimate Ba–Pb–Ti–TiO2-bearing powder mixtures, produced by high-energy vibratory milling, were packed within a fugitive metal can and then compacted and formed into tapes of uniform thickness by cold drawing and rolling. The tape-shaped precursors were oxidized and converted into (Ba,Pb)TiO3-based tapes with a series of heat treatments at ≤1120 °C. With proper control of thermal treatments and chemical additions (Sb2O3 + MnO2 dopants), positive-temperature-coefficient-of-resistivity thermistors were produced that exhibited significant increases in resistivity commencing at temperatures ≥350 °C.

Effect of Magnetic Field Treatment on Temperature-Sensing Property of Polyethylene-Based PTC Composites

2011 ◽  
Vol 335-336 ◽  
pp. 23-27 ◽  
Author(s):  
Chang Ming Li ◽  
Yang Wang ◽  
Xian Wei Yan ◽  
Yan Ming Yang ◽  
Ying Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Positive Temperature Coefficient ◽  
Temperature Sensing ◽  
Room Temperature Resistivity ◽  
Positive Temperature ◽  
Hot Press ◽  
Powder Composites ◽  
Magnetic Field Treatment ◽  
The Magnetic Field ◽  
Press Molding

A static magnetic field is applied during the hot press molding of high-density polyethylene (HDPE)/carbon black (CB)/ferrous powder composites and HDPE/CB/carbon nanotube (CNT) composites. The effect of magnetic field treatment on the temperature-sensing property of polyethylene-based positive temperature coefficient (PTC) composites is investigated. Experimental results indicate that the magnetic field treatment can lead to the alignment of ferrous powders and CNT in HDPE along the direction of the applied external magnetic field, thus guaranteeing the composites have low room-temperature resistivity and high PTC intensity as the concentration of CB is cut down. This also can significantly improve mechanical property and processability of the composites. When the mass concentrations of ferrous powders and CNT are equal, HDPE/CB/ferrous powder composites present better PTC property than HDPE/CB/CNT composites after the magnetic field treatment.

Electronic properties of the actinide metals at low temperatures

1963 ◽  
Vol 276 (1367) ◽  
pp. 553-570 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Low Temperatures ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Al Alloys ◽  
Positive Temperature ◽  
Positive Coefficient ◽  
Disorder Effects ◽  
Temperature Coefficients ◽  
Spin Disorder

The electrical resistivity and thermoelectric power of thorium, uranium, neptunium and plutonium have been measured down to liquid-helium and liquid-hydrogen temperatures. The resistivities are relatively high, especially those of neptunium and plutonium, while all the thermoelectric powers show complicated temperature relations. The temperature dependence of the resistance of a-plutonium is abnormal, being characterized by a small negative temperature coefficient above 105 °K and a large positive coefficient below this temperature. Some plutonium rich d-Pu + Al alloys also show similar behaviour. An explanation in terms of spin-disorder effects seems most reasonable, and it is suggested that both a- and d-plutonium may be antiferromagnetic. The resistance—temperature curves of uranium and neptunium also are unusual in that the positive temperature coefficients decrease monotonically with rising temperature. Possible reasons for this have been discussed.

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