Structural effects in low temperature radioluminescence of aqueous ionic systems

1999 ◽  
Vol 54 (6) ◽  
pp. 567-574 ◽  
Author(s):  
Maria Wypych ◽  
Jerzy Kroh
Keyword(s):  
Low Temperature ◽  
Structural Effects ◽  
Ionic Systems

Influence of Trimethylsilyl Substituents on Primary C - O Bond Lengths at the b-Position: Results from Low-Temperature X-Ray Structural Studies

1997 ◽  
Vol 50 (9) ◽  
pp. 927 ◽  
Author(s):  
Alison J. Green ◽  
William Issa ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Ester Bond ◽  
Structural Studies ◽  
Structural Effects ◽  
X Ray ◽  
Bond Lengths

The β-trimethylsilyl substituent in 2-trimethylsilylethyl p-nitrobenzoate (12b) and 2-trimethylsilylethyl 2,4-dinitrobenzenesulfenate (12c) leads to significant lengthening of the C(alkyl)–O(ester) bond. Lengthening of the Si-CH2 distance in the more electronegative ester (12c) relative to (12b) is also observed. These structural effects are consistent with the presence of σC-Si–σ* C-O interactions.

scholarly journals Simultaneous Enhancement of Mechanical and Magnetic Properties in Extremely-Fine Nanograined Ni-P Alloys

Nanomaterials ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 792
Author(s):  
Qiongyao He ◽  
Wanquan Zhu ◽  
Xiaoxiao Fu ◽  
Ling Zhang ◽  
Guilin Wu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Low Temperature ◽  
Nanocrystalline Materials ◽  
Exchange Interactions ◽  
Second Phase ◽  
Structural Effects ◽  
Microstructural Investigation ◽  
Grain Sizes ◽  
Low Temperature Annealing ◽  
Equilibrium Structures

Exploring structural effects that influence both the mechanics and magnetism in nanocrystalline materials, particularly extremely-fine nanograined ones with grain sizes down to several nanometers, is of high interest for developing multifunctional materials combining superior mechanical and magnetic performances. We found in this work that electrodeposited extremely-fine nanograined Ni-P alloys exhibit a significant enhancement of magnetization, simultaneously along with an increase in hardness, after low-temperature annealing. The relaxation of non-equilibrium structures, precipitation of the second phase and the segregation of P atoms to grain boundaries (GBs) during annealing have then been sequentially evidenced. By systematically comparing the variations in macroscopic and microstructural investigation results among several Ni-P alloys with different P contents, we suggest that the second phase has little effect on magnetization enhancement, and essentially both the structural relaxation and GB segregation can play important roles in hardening by governing GB stability, and in the improvement of magnetization by enhancing Ni–Ni atom exchange interactions.

Probing the Ground-State δ Effect of Group 14 Metal Substituents. X-Ray Structures of cis- and trans-4-Trimethylmetal-Substituted Cyclohexyl p-Nitrobenzenesulfonates

1998 ◽  
Vol 51 (7) ◽  
pp. 555 ◽  
Author(s):  
Alison J. Green ◽  
Victor Van ◽  
Jonathan M. White
Keyword(s):  
Low Temperature ◽  
Ground State ◽  
Structural Studies ◽  
Structural Effects ◽  
Group 14 ◽  
X Ray ◽  
Bond Interaction ◽  
Cis And Trans

Accurate low-temperature X-ray structural studies on trans-4-trimethylsilylcyclohexyl p-nitrobenzene- sulfonate (31) and cis- and trans-4-trimethylstannylcyclohexyl p-nitrobenzenesulfonates (32) and (33) failed to demonstrate the presence of any significant structural effects due to a σM-C-σC-C-σ*C-O through-bond interaction between the C–M σ donor orbital and the σ*C-ONs acceptor orbital.

Structural Effects Behind the Low Temperature Nonconventional Relaxor Behavior of the Sr2NaNb5O15Bronze

2011 ◽  
Vol 50 (23) ◽  
pp. 12091-12098 ◽  
Author(s):  
Almudena Torres-Pardo ◽  
Ricardo Jiménez ◽  
José M. González-Calbet ◽  
Ester Garcı́a-González
Keyword(s):  
Low Temperature ◽  
Relaxor Behavior ◽  
Structural Effects

scholarly journals Co–Cr–O mixed oxides for low–temperature total oxidation of propane: Structural effects, kinetics, and spectroscopic investigation

2020 ◽  
Vol 41 (3) ◽  
pp. 442-453 ◽  
Author(s):  
Wen-Min Liao ◽  
Pei-Pei Zhao ◽  
Bing-Heng Cen ◽  
Ai-Ping Jia ◽  
Ji-Qing Lu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Spectroscopic Investigation ◽  
Mixed Oxides ◽  
Structural Effects ◽  
Total Oxidation

scholarly journals Low-temperature structural effects in the (TMTSF)2PF6and AsF6Bechgaard salts

2013 ◽  
Vol 88 (2) ◽  
Author(s):  
P. Foury-Leylekian ◽  
S. Petit ◽  
I. Mirebeau ◽  
G. André ◽  
M. de Souza ◽  
...  
Keyword(s):  
Low Temperature ◽  
Structural Effects

the effects of resonance with Jupiter in the system of short-period comets

1974 ◽  
Vol 22 ◽  
pp. 193-203
Author(s):  
L̆ubor Kresák
Keyword(s):  
Structural Effects ◽  
Order Resonance ◽  
Mean Motion ◽  
Short Period ◽  
The Mean ◽  
Compound Effect ◽  
Low Order

AbstractStructural effects of the resonance with the mean motion of Jupiter on the system of short-period comets are discussed. The distribution of mean motions, determined from sets of consecutive perihelion passages of all known periodic comets, reveals a number of gaps associated with low-order resonance; most pronounced are those corresponding to the simplest commensurabilities of 5/2, 2/1, 5/3, 3/2, 1/1 and 1/2. The formation of the gaps is explained by a compound effect of five possible types of behaviour of the comets set into an approximate resonance, ranging from quick passages through the gap to temporary librations avoiding closer approaches to Jupiter. In addition to the comets of almost asteroidal appearance, librating with small amplitudes around the lower resonance ratios (Marsden, 1970b), there is an interesting group of faint diffuse comets librating in characteristic periods of about 200 years, with large amplitudes of about±8% in μ and almost±180° in σ, around the 2/1 resonance gap. This transient type of motion appears to be nearly as frequent as a circulating motion with period of revolution of less than one half that of Jupiter. The temporary members of this group are characteristic not only by their appearance but also by rather peculiar discovery conditions.

Exsolution and inversion in pigeonite from the Whin Sill, Northern England

1978 ◽  
Vol 36 (1) ◽  
pp. 474-475
Author(s):  
P.P.K. Smith
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Homogeneous Nucleation ◽  
Silicate Mineral ◽  
Antiphase Boundaries ◽  
Two Phase ◽  
Primitive Form ◽  
The Core ◽  
Nucleation Mechanisms ◽  
And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

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