scholarly journals Temperature dependence of oxygen- and clumped isotope fractionation in carbonates: A study of travertines and tufas in the 6–95°C temperature range

2015 ◽  
Vol 168 ◽  
pp. 172-192 ◽  
Author(s):  
Sándor Kele ◽  
Sebastian F.M. Breitenbach ◽  
Enrico Capezzuoli ◽  
A. Nele Meckler ◽  
Martin Ziegler ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Isotope Fractionation ◽  
Temperature Range ◽  
Clumped Isotope

Tritium isotope fractionation between hydrogen sulphide and methanol

1983 ◽  
Vol 61 (6) ◽  
pp. 1060-1063 ◽  
Author(s):  
Andrzej Wawer ◽  
Jerzy Szydlowski
Keyword(s):  
Temperature Dependence ◽  
Exchange Reaction ◽  
Isotope Effect ◽  
Hydrogen Sulphide ◽  
Gaseous Phase ◽  
Isotope Fractionation ◽  
Simple Relation ◽  
Temperature Range ◽  
Fractionation Factors ◽  
Good Agreement

Tritium isotope fractionation in the exchange reaction between methanol and hydrogen sulphide has been studied in the gaseous phase over the temperature range 283–373 K. It was found that the heavier isotope accumulates in methanol and that the tritium–protium isotope effect characterizing the exchange reaction studied reaches large values: from 2.70 at 373 K to 3.72 at 283 K. The temperature dependence can be described by the simple relation: In α = −0.1221 + 431.5/T. Using observed vibrational frequencies, theoretical fractionation factors could be calculated and good agreement with the experimentally determined values was observed. The results presently obtained were also compared with those obtained for the CH3SH–H2S system.

Specific features of the temperature dependence of tryptophan fluorescence lifetime in the temperature range of −170–20 °C

2020 ◽  
Vol 393 ◽  
pp. 112435
Author(s):  
Peter P. Knox ◽  
Vladimir V. Gorokhov ◽  
Boris N. Korvatovsky ◽  
Nadezhda P. Grishanova ◽  
Sergey N. Goryachev ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Fluorescence Lifetime ◽  
Tryptophan Fluorescence ◽  
Temperature Range

Temperature dependence of chlorine-35 N.Q.R. in 2,6-Dichlorophenol

1978 ◽  
Vol 31 (4) ◽  
pp. 791 ◽  
Author(s):  
R Chandramani ◽  
SP Basavaraju ◽  
N Devaraj
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Brown's Method

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.

scholarly journals PSEUDO-GAP FEATURES OF INTRINSIC TUNNELING IN (HgBr2)-Bi2212 SINGLE CRYSTALS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3758-3763 ◽  
Author(s):  
AUGUST YURGENS ◽  
DAG WINKLER ◽  
TORD CLAESON ◽  
SEONG-JU HWANG ◽  
JIN-HO CHOY
Keyword(s):  
Temperature Dependence ◽  
Single Crystals ◽  
Room Temperature ◽  
Unit Cell ◽  
Superconducting Gap ◽  
Axis Direction ◽  
Temperature Range ◽  
Dynamic Conductance

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.

The Design of AlGaN/GaN HEFT-Micro-Accelerometer and Temperature- Dependence Electrical Performance

2011 ◽  
Vol 483 ◽  
pp. 174-179 ◽  
Author(s):  
Ting Liang ◽  
Jian Jun Tang ◽  
Qian Qian Zhang ◽  
Yong Wang ◽  
Jing Li ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Electrical Performance ◽  
Saturation Current ◽  
Temperature Range ◽  
Different Temperatures ◽  
Piezoresistance Coefficient ◽  
Micro Accelerometer

In this paper, We use a novel principle to detect acceleration and report how I-V characteristics and piezoresistance coefficient of AlGaN/GaN HEFT-micro-accelerometer are affected by setting different temperatures. It is shown that saturation current of device would go down if the temperature goes up, which is about 0.028mA/°C, based on the research. However, the device can work well at the temperature range of -50°C to 50°C, which indicates that it can work safely in the larger temperature range.

NQR and Crystal Structure of 4,5-Dichloroimidazole, C3H2N2Cl2

1992 ◽  
Vol 47 (1-2) ◽  
pp. 177-181 ◽  
Author(s):  
Shi-Qi Dou ◽  
Alarich Weiss
Keyword(s):  
Crystal Structure ◽  
Phase Transition ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Unit Cell ◽  
Space Group ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Group D

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.

scholarly journals Heterogeneous loss of OH on NaCl and NH<sub>4</sub>NO<sub>3</sub> at tropospheric temperatures

1996 ◽  
Vol 14 (6) ◽  
pp. 659-664 ◽  
Author(s):  
A. V. Ivanov ◽  
Y. M. Gershenzon ◽  
F. Gratpanche ◽  
P. Devolder ◽  
J.-P. Sawerysyn
Keyword(s):  
Temperature Dependence ◽  
Detection Method ◽  
Tropospheric Chemistry ◽  
Minor Role ◽  
Oh Radicals ◽  
Flow Tube ◽  
Temperature Range ◽  
Uptake Coefficients

Abstract. The uptake coefficients (Γ) for OH radicals on some dry salts of tropospheric interest (NaCl and NH4NO3) have been investigated as a function of temperature using the flow tube technique combined with an EPR spectrometer as a detection method. The temperature dependence of Γ-values measured over the temperature range 245–340 K can be expressed in Arrhenius form: ΓOHNaCl=(1.2±0.7)×10–5exp[(1750±200)/T] and ΓOHNH4NO3=(1.4±0.5)×10–4exp[(1000±100)/T]. These Arrhenius expressions lead to very similar Γ-values (~4×10–3) for both salts studied at 300 K. It is shown that the heterogeneous OH sinks on solids aerosol play a very minor role in tropospheric chemistry in comparison with the homogeneous sinks.

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