Vibrational spectra of diatomic chains

1960 ◽  
Vol 254 (1279) ◽  
pp. 507-521 ◽  
Keyword(s):  
Vibrational Spectra ◽  
Three Dimensional ◽  
Chain Structure ◽  
Mass Ratio ◽  
Lattice Order ◽  
Defect Modes ◽  
Disordered Chain ◽  
The Way

Quantitatively accurate results for the vibrational spectra of disordered diatomic chains have been computed for four systems over a complete range of lattice order. The spectra obtained are far more complex than has hitherto been suspected, a most detailed array of peaks and valleys becoming apparent for the completely disordered chain at a mass ratio of about 2. The theory of defect modes in nearly ordered lattices shows the association of a number of the peaks with particular kinds of localized chain structure and points the way to possible developments for three-dimensional systems.

Raman Spectra of Ion Implanted Graphite

1981 ◽  
Vol 7 ◽  
Author(s):  
B.S. Elman ◽  
H. Mazurek ◽  
M.S. Dresselhaus ◽  
G. Dresselhaus
Keyword(s):  
Raman Spectroscopy ◽  
Ion Implantation ◽  
Raman Spectra ◽  
Annealing Temperature ◽  
Annealing Process ◽  
Lattice Order ◽  
Annealing Temperatures ◽  
High Fluences ◽  
Lattice Damage ◽  
The Way

ABSTRACTRaman spectroscopy is used in a variety of ways to monitor different aspects of the lattice damage caused by ion implantation into graphite. Particular attention is given to the use of Raman spectroscopy to monitor the restoration of lattice order by the annealing process, which depends critically on the annealing temperature and on the extent of the original lattice damage. At low fluences the highly disordered region is localized in the implanted region and relatively low annealing temperatures are required, compared with the implantation at high fluences where the highly disordered region extends all the way to the surface. At high fluences, annealing temperatures comparable to those required for the graphitization of carbons are necessary to fully restore lattice order.

Remarks on marine and continental biogeography: an areographical viewpoint

1994 ◽  
Vol 343 (1303) ◽  
pp. 71-78 ◽  
Keyword(s):  
Species Richness ◽  
Baltic Sea ◽  
Three Dimensional ◽  
Wide Spread ◽  
The Baltic Sea ◽  
Biogeographical Regions ◽  
The Baltic ◽  
The Way

Differences and similarities in the way marine and continental organisms occupy space are briefly reviewed. Among them, the ‘peninsula effect’ (the decline of species richness with distance from the source) is compared with the ‘bay effect’. Two cases, corals in Mochima Bay, Venezuela and fishes in the Baltic Sea, are presented as examples. The facts that the world’s oceans are larger, continuous and three-dimensional, with fewer evident geographical barriers than there are on land, explain why marine biogeographical regions are less welldefined and geographical ranges of marine taxa more wide-spread. I his generalization has, however, been questioned following recent findings of extremely rich and highly endemic benthic faunas. This problem is discussed using an index of cosmopolitanism to compare terrestrial and marine biotas.

Navigating in a volumetric world: Metric encoding in the vertical axis of space

2013 ◽  
Vol 36 (5) ◽  
pp. 546-547 ◽  
Author(s):  
Theresa Burt de Perera ◽  
Robert Holbrook ◽  
Victoria Davis ◽  
Alex Kacelnik ◽  
Tim Guilford
Keyword(s):  
Spatial Information ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Vertical Component ◽  
Vertical Axis ◽  
Orthogonal Axis ◽  
Experimental Protocols ◽  
Three Dimensional Space ◽  
The Way

AbstractAnimals navigate through three-dimensional environments, but we argue that the way they encode three-dimensional spatial information is shaped by how they use the vertical component of space. We agree with Jeffery et al. that the representation of three-dimensional space in vertebrates is probably bicoded (with separation of the plane of locomotion and its orthogonal axis), but we believe that their suggestion that the vertical axis is stored “contextually” (that is, not containing distance or direction metrics usable for novel computations) is unlikely, and as yet unsupported. We describe potential experimental protocols that could clarify these differences in opinion empirically.

scholarly journals Crystal structure of a polymeric calcium levulinate dihydrate:catena-poly[[diaquacalcium]-bis(μ2-4-oxobutanoato)]

2015 ◽  
Vol 71 (5) ◽  
pp. 494-497
Author(s):  
Ananda S. Amarasekara ◽  
Dominique T. Sterling-Wells ◽  
Carlos Ordonez ◽  
Marie-Josiane Ohoueu ◽  
Marina S. Fonari
Keyword(s):  
Hydrogen Bonds ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Axial Direction ◽  
Chain Structure ◽  
Dimensional Structure ◽  
Polymeric Chain ◽  
Water Molecules ◽  
Carboxylate Ligands ◽  
Length Range

In the title calcium levulinate complex, [Ca(C5H7O3)2(H2O)2]n, the Ca2+ion lies on a twofold rotation axis and is octacoordinated by two aqua ligands and six O atoms from four symmetry-related carboxylate ligands, giving a distorted square-antiprismatic coordination stereochemistry [Ca—O bond-length range = 2.355 (1)–2.599 (1) Å]. The levulinate ligands act both in a bidentate carboxylO,O′-chelate mode and in a bridging mode through one carboxyl O atom with an inversion-related Ca2+atom, giving a Ca...Ca separation of 4.0326 (7) Å. A coordination polymeric chain structure is generated, extending along thec-axial direction. The coordinating water molecules act as double donors and participate in intra-chain O—H...O hydrogen bonds with carboxyl O atoms, and in inter-chain O—H...O hydrogen bonds with carbonyl O atoms, thus forming an overall three-dimensional structure.

Selecting Suitable Probes Distances for Sizing Deep Surface Cracks Using the DCPD Technique

2006 ◽  
Vol 129 (1) ◽  
pp. 205-210 ◽  
Author(s):  
Fumio Takeo ◽  
Masumi Saka ◽  
S. Reaz Ahmed ◽  
Seiichi Hamada ◽  
Manabu Hayakawa
Keyword(s):  
Three Dimensional ◽  
Potential Drop ◽  
Surface Cracks ◽  
Deep Surface ◽  
Input And Output ◽  
Wide Range ◽  
Current Input ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Way

In this study, the way to enhance the sensitivity of evaluating deep surface cracks by DCPD technique using four probes is considered. The potential drops across two-dimensional cracks having different depths are analyzed by the three-dimensional finite-element method. The effect of the distance between current input and output probes and the distance between measuring probes on the change in potential drops are analyzed for a wide range of crack depths. By extending the distance between current input and output probes, the change in potential drop with the change in the depth of deeper crack becomes large. But the voltage of potential drop becomes small to measure. Finally, the way to select the appropriate distances between the probes for the measuring sensor is shown from the viewpoints of sensitivity and the required current.

Notizen: Schwingungsspektren der Gold(I)-halogenide AuX (X = Cl, Br und I); Strukturprognosen für AuCl und AuBr / Vibrational Spectra of the Aurous Halides AuX (X= Cl, Br and I); Structural Prognoses for AuCl and AuBr

1974 ◽  
Vol 29 (11-12) ◽  
pp. 806-807 ◽  
Author(s):  
Dietrich Breitinger ◽  
Heiko Leuchtenstern
Keyword(s):  
Vibrational Spectra ◽  
Chain Structure ◽  
Force Constants ◽  
Bond Angles ◽  
Bond Lengths

Chain structure, Force constantsFrom vibrational spectra chain structures are predicted for AuCl and AuBr; bond angles, bond lengths and force constants have been estimated for these aurous halides.

scholarly journals Digital Sensoriality: The Neolithic Figurines from Koutroulou Magoula, Greece

2019 ◽  
Vol 29 (4) ◽  
pp. 625-652 ◽  
Author(s):  
Costas Papadopoulos ◽  
Yannis Hamilakis ◽  
Nina Kyparissi-Apostolika ◽  
Marta Díaz-Guardamino
Keyword(s):  
Computational Methods ◽  
Three Dimensional ◽  
The Public ◽  
The Past ◽  
Artistic Representations ◽  
Dynamic Objects ◽  
Physical Objects ◽  
Intellectual Climate ◽  
The Way

The image-based discourse on clay figurines that treated them as merely artistic representations, the meaning of which needs to be deciphered through various iconological methods, has been severely critiqued and challenged in the past decade. This discourse, however, has largely shaped the way that figurines are depicted in archaeological iterations and publications, and it is this corpus of images that has in turn shaped further thinking and discussion on figurines, especially since very few people are able to handle the original, three-dimensional, physical objects. Building on the changing intellectual climate in figurine studies, we propose here a framework that treats figurines as multi-sensorial, affective and dynamic objects, acting within distinctive, relational fields of sensoriality. Furthermore, we situate a range of digital, computational methods within this framework in an attempt to deprive them of their latent Cartesianism and mentalism, and we demonstrate how we have applied them to the study of Neolithic figurines from the site of Koutroulou Magoula in Greece. We argue that such methodologies, situated within an experiential framework, not only provide new means of understanding, interpretation and dissemination, but, most importantly, enable researchers and the public to explore the sensorial affordances and affective potential of things, in the past as well as in the present.

scholarly journals Crystal structure of sodium (1S)-D-lyxit-1-ylsulfonate

2016 ◽  
Vol 72 (5) ◽  
pp. 628-631
Author(s):  
Alan H. Haines ◽  
David L. Hughes
Keyword(s):  
Crystal Structure ◽  
Three Dimensional ◽  
Chain Structure ◽  
Zigzag Chain ◽  
Sugar Chain ◽  
Open Chain ◽  
Torsion Angles ◽  
Hydroxymethyl Group ◽  
Sodium Hydrogen ◽  
Group Form

The title compound, Na+·C5H11O8S−[systematic name: sodium (1S,2S,3S,4R)-1,2,3,4,5-pentahydroxypentane-1-sulfonate], is formed by reaction of D-lyxose with sodium bisulfite (sodium hydrogen sulfite) in water. The anion has an open-chain structure in which one of the oxygen atoms of the sulfonate residue, the S atom, the C atoms of the sugar chain and the O atom of the hydroxymethyl group form an essentially planar zigzag chain with the corresponding torsion angles lying between 179.80 (11) and 167.74 (14)°. A three-dimensional bonding network exists in the crystal structure involving hexacoordination of sodium ions by O atoms, three of which are provided by a single D-lyxose–sulfonate unit and the other three by two sulfonate groups and one hydroxymethyl group, each from separate units of the adduct. Extensive intermolecular O—H...O hydrogen bonding supplements this bonding network.

scholarly journals A note on the mirror-symmetric coherent structure in plane Couette flow

2013 ◽  
Vol 727 ◽  
Author(s):  
M. Nagata
Keyword(s):  
Couette Flow ◽  
Coherent Structure ◽  
Rotation Rate ◽  
Symmetric Solution ◽  
Three Dimensional ◽  
Plane Couette Flow ◽  
System Rotation ◽  
The Way

AbstractWe note that the mirror-symmetric solution in plane Couette flow, found recently by Gibson, Halcrow & Cvitanović (J. Fluid Mech., vol. 611, 2009, pp. 107–130) and Itano & Generalis (Phys. Rev. Lett., vol. 102, 2009, p. 114501), belongs to the solution group classified as ‘ribbon’ in rotating-plane Couette flow (RPCF). It represents a subcritical (in terms of the system rotation) solution at zero rotation rate on the three-dimensional tertiary flow branch which bifurcates from thesecondstreamwise-independent flow in RPCF. The way of its appearance is similar to that of the Nagata solution (J. Fluid Mech., vol. 217, 1990, pp. 519–527), which lies on the subcritical three-dimensional tertiary flow branch bifurcating from thefirststreamwise-independent flow in RPCF.

scholarly journals Kristallstruktur und Schwingungsspektren von Zn(NH3)4(ClO4)2 / Crystal Structure and Vibrational Spectra of Zn(NH3)4(ClO4)2

1994 ◽  
Vol 49 (9) ◽  
pp. 1163-1168 ◽  
Author(s):  
Harald Hillebrecht ◽  
Gerhard Thiele ◽  
Alrik Koppenhöfer ◽  
Heinrich Vahrenkamp
Keyword(s):  
Crystal Structure ◽  
Vibrational Spectra ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Complex Ions ◽  
Zintl Phase ◽  
Dimensional Network ◽  
Tetrahedral Voids ◽  
Raman And Ir Spectra

The title compound Zn(NH3)4(ClO4)2 crystallizes in the space group F4̄3m with a = 10.240(1) Å. The crystal structure consists of tetrahedral Zn(NH3)4 cations and two nonequivalent ClO4 anions with crystallographic Td symmetry. The complex ions constitute an arrangement which is known from the Zintl phase MgAgAs. The Zn(NH3)4 cations are ccp packed with perchlorate anions in octahedral and tetrahedral voids. Whereas the ClO4 ions centered at tetrahedral holes do not interact with the other lattice components, the perchlorate ions in the octahedral voids are connected with the ammine ligands by a hydrogen bonded three-dimensional network involving all their N, H, and O atoms. The repeating unit of this network is a N4O4(μ-H)12 cube with N-H = 1.19(2) Å and O···H = 1.98(2)Å . Raman and IR spectra were recorded between 150 and 4000 cm-1. All the expected internal modes of the complex ions could be detected and assigned. The crystallographically different ClO4 anions have nearly the same vibrational spectra, only a slight splitting of two IR modes is observed

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