scholarly journals Evidencing the relationship between isomer spectra and melting: the 20- and 55-atom silver and gold cluster cases

2019 ◽  
Vol 21 (45) ◽  
pp. 24857-24866 ◽  
Author(s):  
Mathias Rapacioli ◽  
Fernand Spiegelman ◽  
Nathalie Tarrat
Keyword(s):  
Gold Cluster ◽  
Silver Clusters ◽  
Excitation Spectra ◽  
Melting Properties ◽  
Structural Excitation ◽  
The Relationship

The present work highlights the links between melting properties and structural excitation spectra of small gold and silver clusters.

Luminescent Property of Al2O3:Ce3+ Thin Films

2011 ◽  
Vol 130-134 ◽  
pp. 23-26 ◽  
Author(s):  
Shao Feng Yan ◽  
Kai Ge Miao
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Flow Rate ◽  
Luminescence Intensity ◽  
Room Temperature ◽  
Luminescent Properties ◽  
Cerium Chloride ◽  
Medium Frequency ◽  
Excitation Spectra ◽  
The Relationship

The Al2O3 films doped with Ce3 + were deposited on slides by the medium-frequency reaction magnetron sputtering process, to which the power is constant, Ar flow rate 70 sccm, O2 flow rate 25~45sccm and sputtering time 90min at room temperature. The relationship between the luminescent properties of Al2O3:Ce3 + films and the doped amount of Ce3 + in the films was studied. The presence of Ce3 + and stoichiometry of those films were determined. It was observed that the total luminescence intensity increases and the peak positions are strongly dependent on Ce3+ concentration in the films. The analysis of luminescent excitation spectra showed that the luminance is due to the Ce3+ concentration in the cerium chloride aggregate formed in the films.

scholarly journals Molecular structure and melting: implications for phase change materials

2018 ◽  
Vol 96 (7) ◽  
pp. 722-729 ◽  
Author(s):  
John A. Noël ◽  
Samer Kahwaji ◽  
Mary Anne White
Keyword(s):  
Molecular Structure ◽  
Phase Change ◽  
Phase Change Materials ◽  
Alkyl Chains ◽  
Melting Temperatures ◽  
Enthalpy Changes ◽  
Melting Properties ◽  
Load Leveling ◽  
The Relationship ◽  
Selection Of

Phase change materials (PCMs) offer a promising technology for thermal energy storage, load leveling, and peak shifting applications. A desirable PCM has a melting temperature within the temperature boundaries of its application and a high change in enthalpy on melting. Knowledge of the relationships between these thermodynamic properties and molecular structure would advance informed selection of PCM candidates for a given application. In the present investigation, the relationship between structure (length of alkyl chains) and melting properties has been investigated for isomeric esters, showing that esters containing longer individual alkyl chains have higher melting temperatures and higher enthalpy changes on melting. The melting entropy changes, however, are relatively independent of the alkyl chain distribution.

THE CATALYTIC ROLE OF SMALL COINAGE-METAL CLUSTERS IN PHOTOGRAPHY

1996 ◽  
Vol 03 (01) ◽  
pp. 1105-1108 ◽  
Author(s):  
T. LEISNER ◽  
CH. ROSCHE ◽  
S. WOLF ◽  
F. GRANZER ◽  
L. WÖSTE
Keyword(s):  
Kinetic Energy ◽  
Redox Potential ◽  
Gold Cluster ◽  
Metal Cluster ◽  
Silver Halide ◽  
Silver Cluster ◽  
Silver Clusters ◽  
Coinage Metal ◽  
Catalytic Role

We model the generation of the photographic latent image in silver-halide systems by the deposition of size-selected silver and gold clusters onto silver-halide microcrystals. Coinage-metal cluster cations were produced in a sputtering arrangement, mass-selected by a quadrupole mass filter, and deposited with a well-controlled kinetic energy onto binderfree silver-bromide crystals. After exposure to the cluster beam, the samples were developed at a defined redox potential. The photographic action of the clusters was investigated as a function of their size, the coverage of the sample with clusters, the kinetic energy of the clusters during the deposition, and the redox potential of the developer. Development was observed after the deposition of [Formula: see text] or larger silver-cluster cations, and under some development conditions, after deposition of [Formula: see text]. No development was observed after the deposition of smaller silver clusters, and after the deposition of gold cluster cations [Formula: see text](n≤9).

On the relationship between luminescence excitation spectra and feldspar mineralogy

1996 ◽  
Vol 26 (1) ◽  
pp. 93-101 ◽  
Author(s):  
N.R.J. Poolton ◽  
L. Bøtter-Jensen ◽  
O. Johnsen
Keyword(s):  
Excitation Spectra ◽  
The Relationship

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Tinkering with cognitive gadgets: Cultural evolutionary psychology meets active inference

2019 ◽  
Vol 42 ◽  
Author(s):  
Paul Benjamin Badcock ◽  
Axel Constant ◽  
Maxwell James Désormeau Ramstead
Keyword(s):  
Evolutionary Psychology ◽  
Research Program ◽  
Active Inference ◽  
Innovative Research ◽  
Cognitive Faculties ◽  
Cultural Evolutionary ◽  
The Relationship

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.

Production and STEM examination of controlled-size silver clusters

1983 ◽  
Vol 41 ◽  
pp. 338-339
Author(s):  
M. A. Listvan ◽  
R. P. Andres
Keyword(s):  
Cluster Size ◽  
Metal Clusters ◽  
Experimental Parameter ◽  
Carbon Films ◽  
Metal Species ◽  
Silver Clusters ◽  
Free Jet ◽  
Size Dependent ◽  
Cluster Properties ◽  
Controllable Size

Knowledge of the function and structure of small metal clusters is one goal of research in catalysis. One important experimental parameter is cluster size. Ideally, one would like to produce metal clusters of regulated size in order to characterize size-dependent cluster properties.A source has been developed which is capable of producing microscopic metal clusters of controllable size (in the range 5-500 atoms) This source, the Multiple Expansion Cluster Source, with a Free Jet Deceleration Filter (MECS/FJDF) operates as follows. The bulk metal is heated in an oven to give controlled concentrations of monomer and dimer which were expanded sonically. These metal species were quenched and condensed in He and filtered to produce areosol particles of a controlled size as verified by mass spectrometer measurements. The clusters were caught on pre-mounted, clean carbon films. The grids were then transferred in air for microscopic examination. MECS/FJDF was used to produce two different sizes of silver clusters for this study: nominally Ag6 and Ag50.

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