Temperature-dependence of 35Cl N.Q.R. in sodium chloroacetate

1976 ◽  
Vol 29 (11) ◽  
pp. 2363 ◽  
Author(s):  
R Chandramani ◽  
N Devaraj ◽  
VSS Sastry ◽  
J Ramakrishna

N.q.r. in sodium chloroacetate has been investigated at temperatures from 77 K to room temperature (c.300 K). A single line has been observed throughout this temperature range. Torsional frequencies of the molecule have been calculated in the above temperature range from Bayer's theory. Also the temperature coefficient of the torsional frequencies has been calculated by Brown's method.

1978 ◽  
Vol 31 (4) ◽  
pp. 791 ◽  
Author(s):  
R Chandramani ◽  
SP Basavaraju ◽  
N Devaraj

Chlorine n.q.r, in 2,6-dichlorophenol has been investigated at temperatures from 77 K to room temperature. Two resonance lines due to chemically inequivalent sites have been observed throughout this temperature range. Torsional frequencies of the molecule have been calculated at temperatures from 77 to 300 K according to Bayer's theory and Brown's method. Also the temperature coefficients of the torsional frequencies have been calculated.


1999 ◽  
Vol 13 (29n31) ◽  
pp. 3758-3763 ◽  
Author(s):  
AUGUST YURGENS ◽  
DAG WINKLER ◽  
TORD CLAESON ◽  
SEONG-JU HWANG ◽  
JIN-HO CHOY

The c-axis tunneling properties of both pristine Bi2212 and its HgBr 2 intercalate have been measured in the temperature range 4.2-250 K. Lithographically patterned 7-10 unit-cell heigh mesa structures on the surfaces of these single crystals were investigated. Clear SIS-like tunneling curves for current applied in the c-axis direction have been observed. The dynamic conductance d I/ d V(V) shows both sharp peaks corresponding to a superconducting gap edge and a dip feature beyond the gap, followed by a wide maximum, which persists up to a room temperature. Shape of the temperature dependence of the c-axis resistance does not change after the intercalation suggesting that a coupling between CuO 2-bilayers has little effect on the pseudogap.


1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss

AbstractThe two line 35Cl NQR spectrum of 4,5-dichloroimidazole was measured in the temperature range 77≦ T/K ≦ 389. The temperature dependence of the NQR frequencies conforms with the Bayer model and no phase transition is indicated in the curves v ( 35Cl)= f(T). Also the temperature coefficients of the 35Cl NQR frequencies are "normal". At 77 K the 35Cl NQR frequencies are 37.409 MHz and 36.172 MHz and at 389 K 35.758 MHz and 34.565 MHz. The compound crystallizes at room temperature with the tetragonal space group D44-P41212, Z = 8 molecules per unit cell; at 295 K : a = 684.2(5) pm, c = 2414.0(20) pm. The relations between the crystal structure and the NQR spectrum are discussed.


Author(s):  
Munish Pandey ◽  
Richa Badlani

In polymerization of was carried out in the presence of to synthesize – composites by chemical oxidation method. The / have been synthesized with various compositions (10, 15, 20, 25 and 30 ) of in in aquas medium at room temperature. The – composites were characterized by infrared spectroscopy (IR). The d.c. conductivity was studied in the temperature range from 40–100°C. The dimensions of in the matrix have a greater influence on the observed conductivity values.


2007 ◽  
Vol 561-565 ◽  
pp. 459-462
Author(s):  
Katsushi Tanaka ◽  
Hiromitsu Ide ◽  
Yoshinori Sumi ◽  
Kyosuke Kishida ◽  
Haruyuki Inui

Compressive deformation of L10-ordered single crystals of FePd whose c/a ratio less than unity have been investigated from room temperature to 823 K. The results show that the critical resolved shear stress (CRSS) for octahedral glide of ordinary dislocations is smaller than that of super-lattice dislocations in all the temperature range investigated, that is the opposite sense to the case of Ti-56 mol% Al. The CRSS for ordinary dislocations virtually independent to the temperature. On the other hand, the CRSS for super dislocations exhibits a weak positive temperature dependence from room temperature up to 573 K and decreases in higher temperatures.


1971 ◽  
Vol 49 (11) ◽  
pp. 1965-1967 ◽  
Author(s):  
Harry Watts

The diffusion coefficients in air of 1,1-dichloroethane, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene have been measured over a temperature range from room temperature to close to their boiling points by a rate of evaporation method.


2003 ◽  
Vol 18 (2) ◽  
pp. 537-541 ◽  
Author(s):  
Ping-chu Wang ◽  
Xiao-ming Pan ◽  
Dong-lin Li ◽  
Yuan-wei Song ◽  
Hao-su Luo ◽  
...  

Piezoelectric properties k33 and d33 of 0.67 Pb(Mg1/3Nb2/3)O3–0.33 PbTiO3 single crystals grown by a modified Bridgman method were measured in the temperature range of 20–150 °C. Recoverability of the properties after the samples were heated to 110 °C, above the ferroelectric–ferroelectric (F–F) phase transition temperature of the composition, was found. From 20 to approximately 80 °C, k33 increases slightly, while d33 is almost doubled. Between approximately 90 and 100 °C, k33 decreases sharply to roughly a level of PZT-5 ceramics and d33 decreases to about 700 pC/N. They increase again with further increase of temperature; at 140 °C they attain 0.74 and approximately 1300 pC/N, respectively, and then decrease quickly and approach zero at about 150 °C. When heating to 110 °C followed by cooling to room temperature, the property decay is small. After more than one dozen heating–cooling cycles, k33 and d33 tend to be stable at 0.89 and approximately 1220 pC/N, respectively. The results might be helpful for device design and applications of PMN–PT single crystals.


1963 ◽  
Vol 18 (3) ◽  
pp. 347-350 ◽  
Author(s):  
M. S. Raman ◽  
R. Kumar ◽  
R. L. Datta

The effects of cathode material and temperature on the separation factor in the electrolytic enrichment of deuterium are investigated in the temperature range 30°—60°C. Mild steel cathodes give separation factors higher than those for nickel, silver, platinum and tin, whereas an alloy of mild steel +7.85% tin gives still higher separation factors. The temperature coefficient of the separation factor (da/dT) for cathodes of tin and for an alloy of mild steel + tin (62.3%) is positive, whereas for other cathodes studied, da/dT is negative. The temperature dependence of the separation factor is decreased by alloying mild steel with tin. It becomes zero for the alloy with 39.5% tin.


Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1758 ◽  
Author(s):  
Jing Li ◽  
Chang Chang ◽  
Xue Li ◽  
Yang Li ◽  
Guoqiang Guan

Positive temperature coefficient (PTC) materials have many applications in self-regulating heating; however, they are generally used in the high temperature range, and their use in the room temperature range have rarely been reported. A new kind of PTC material with the Curie temperature of 37 °C was proposed in this study. The material was prepared by adding 6wt % carbon black (CB) and 5wt % dioctyl phthalate (DOP) into the copolymer of ethylene vinyl acetate (EVA) and lauric acid (LA) (1:3). The results showed that it had an exceptionally high PTC intensity of 5.5 and rationally low electrical resistivity of 600 Ω·cm. at room temperature. And this PTC material also shows a preferable repeatability in the PTC intensity after the thermal cycle of 4th. Moreover, the PTC material shows a great potential application in warming the human body in a cold environment.


1993 ◽  
Vol 316 ◽  
Author(s):  
F. Priolo ◽  
G. Franzó ◽  
S. Coffa ◽  
A. Polman ◽  
V. Bellani ◽  
...  

ABSTRACTIn this paper our recent work on erbium implantation for optical doping of silicon is reviewed. It is shown that O co-implantation plays a key role both in providing Er with the appropriate chemical surrounding and in allowing the incorporation of high Er concentrations in thick Si layers without the formation of twins and/or precipitates. The luminescence intensity in Er and O co-implanted samples shows a much weaker temperature dependence (a decrease by a factor of 30 from 77K to 300K) than in samples without O (a decrease by 3 orders of magnitude in the same temperature range). This allowed us to observe room temperature photo- and electro-luminescence in Er and O co-doped samples. The temperature dependence of the luminescence in these samples has been determined to be due to non-radiative de-excitation processes. These data are reported and discussed.


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