Polymorphism and structure–property relations

2020 ◽  
pp. 273-341
Author(s):  
Joel Bernstein
Keyword(s):  
Second Harmonic ◽  
Three Dimensional ◽  
Spectroscopic Studies ◽  
Photochemical Reactions ◽  
Structure Property ◽  
Time Resolved ◽  
Property Relations ◽  
High Pressure Studies ◽  
Organic Magnetic Materials ◽  
The One

Chapter 6 deals with the connection between the structure and properties of solids as revealed and studied in polymorphic systems. The subject is divided into properties that depend on the one hand on the bulk—that is, the three-dimensional arrangement of the molecules and the interactions among them—and on the other hand the consideration of the crystal as an “oriented gas” serving to act as a matrix for the molecules to permit the study of molecular properties. Among the properties described in the former category are electrical conductivity, organic magnetic materials, photovoltaicity and photoconductivity, second harmonic generation, chromoisomerism, photochromism, thermochromism and mechanochromism, and the mechanosalient effect. The latter category includes a discussion of spectroscopic studies (infrared, Raman, and ultraviolet/visible), excimer phenomena, time-resolved studies of excited states, photochemical reactions and thermal and gas reactions, along with a variety of emission phenomena. The chapter closes with a brief survey of rapidly emerging and developing high pressure studies

In Situ Raman Spectroscopic Studies of Liquid Carbon Tetrachloride (CCl4) Under Static and Laser-Driven Shock Compression

2019 ◽  
Vol 73 (12) ◽  
pp. 1420-1427
Author(s):  
Usha Rao ◽  
Shivanand Chaurasia ◽  
C. D. Sijoy ◽  
Vinayak Mishra ◽  
M. N. Deo
Keyword(s):  
Carbon Tetrachloride ◽  
Shock Compression ◽  
Spectroscopic Studies ◽  
Raman Signal ◽  
Time Resolved ◽  
Raman Spectroscopic ◽  
Bending Mode ◽  
Raman Modes ◽  
Diamond Anvil ◽  
The One

High pressure (up to ∼2.2 GPa) Raman scattering studies were performed in carbon tetrachloride (CCl4) under static and dynamic compressions using diamond anvil cell (DAC) and laser-driven shock methods, respectively, and their results are compared. The laser-driven shock experiments were conducted in a glass-confined target geometry. The symmetric stretching mode ν1, symmetric bending mode ν2, and asymmetric bending mode ν4 blueshifts with pressure. Mode Gruneisen parameters were obtained for the above Raman modes. Time-resolved Raman spectroscopic (TRRS) studies were performed under laser-driven shock compression at different delay times. Shock velocity deduced from the intensity ratios of Raman signal scattered from unshocked and shocked regions of symmetric stretching mode is in agreement with the one obtained from one-dimensional hydrodynamic simulations.

Characterization of Structure-Property Relations and Second Harmonic Generation of 6-Methoxy-2-Naphthaldehyde

2021 ◽  
pp. 1-13
Author(s):  
D. Rajaniverma ◽  
D. Jagadeeswara Rao ◽  
P. V. Prasanna Kumar ◽  
V. Seetaramaiah ◽  
Y. Ramakrishna
Keyword(s):  
Second Harmonic Generation ◽  
Harmonic Generation ◽  
Second Harmonic ◽  
Structure Property ◽  
Property Relations

Diffraction contrast of dislocations in icosahedral quasicrystals

1990 ◽  
Vol 48 (4) ◽  
pp. 454-455
Author(s):  
K. Urban ◽  
Z. Zhang ◽  
M. Wollgarten ◽  
D. Gratias
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Complete Characterization ◽  
Extinction Condition ◽  
Burgers Vector ◽  
Diffraction Contrast ◽  
Lattice Geometry ◽  
Reference Space ◽  
Icosahedral Quasicrystals ◽  
The One

Recently dislocations have been observed by electron microscopy in the icosahedral quasicrystalline (IQ) phase of Al65Cu20Fe15. These dislocations exhibit diffraction contrast similar to that known for dislocations in conventional crystals. The contrast becomes extinct for certain diffraction vectors g. In the following the basis of electron diffraction contrast of dislocations in the IQ phase is described. Taking account of the six-dimensional nature of the Burgers vector a “strong” and a “weak” extinction condition are found.Dislocations in quasicrystals canot be described on the basis of simple shear or insertion of a lattice plane only. In order to achieve a complete characterization of these dislocations it is advantageous to make use of the one to one correspondence of the lattice geometry in our three-dimensional space (R3) and that in the six-dimensional reference space (R6) where full periodicity is recovered . Therefore the contrast extinction condition has to be written as gpbp + gobo = 0 (1). The diffraction vector g and the Burgers vector b decompose into two vectors gp, bp and go, bo in, respectively, the physical and the orthogonal three-dimensional sub-spaces of R6.

Exploring the Multidimensional Facets of Authoritarianism: Authoritarian Aggression and Social Dominance Orientation

2008 ◽  
Vol 67 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Stefano Passini
Keyword(s):  
Social Dominance ◽  
Factor Model ◽  
Three Dimensional ◽  
Social Dominance Orientation ◽  
Model Fit ◽  
Regression Analyses ◽  
One Dimensional ◽  
Confirmatory Factor ◽  
The One ◽  
Better Than

The relation between authoritarianism and social dominance orientation was analyzed, with authoritarianism measured using a three-dimensional scale. The implicit multidimensional structure (authoritarian submission, conventionalism, authoritarian aggression) of Altemeyer’s (1981, 1988) conceptualization of authoritarianism is inconsistent with its one-dimensional methodological operationalization. The dimensionality of authoritarianism was investigated using confirmatory factor analysis in a sample of 713 university students. As hypothesized, the three-factor model fit the data significantly better than the one-factor model. Regression analyses revealed that only authoritarian aggression was related to social dominance orientation. That is, only intolerance of deviance was related to high social dominance, whereas submissiveness was not.

Sea Urchins and Circuses: The Modernist Natural Histories of Jean Painlevé and Alexander Calder

2018 ◽  
Vol 13 (2) ◽  
pp. 187-211
Author(s):  
Patricia E. Chu
Keyword(s):  
New Media ◽  
Sea Urchins ◽  
Life Sciences ◽  
Three Dimensional ◽  
Machine Age ◽  
Avant Garde ◽  
History Of ◽  
And Performance ◽  
The One ◽  
Natural Historian

The Paris avant-garde milieu from which both Cirque Calder/Calder's Circus and Painlevé’s early films emerged was a cultural intersection of art and the twentieth-century life sciences. In turning to the style of current scientific journals, the Paris surrealists can be understood as engaging the (life) sciences not simply as a provider of normative categories of materiality to be dismissed, but as a companion in apprehending the “reality” of a world beneath the surface just as real as the one visible to the naked eye. I will focus in this essay on two modernist practices in new media in the context of the history of the life sciences: Jean Painlevé’s (1902–1989) science films and Alexander Calder's (1898–1976) work in three-dimensional moving art and performance—the Circus. In analyzing Painlevé’s work, I discuss it as exemplary of a moment when life sciences and avant-garde technical methods and philosophies created each other rather than being classified as separate categories of epistemological work. In moving from Painlevé’s films to Alexander Calder's Circus, Painlevé’s cinematography remains at the forefront; I use his film of one of Calder's performances of the Circus, a collaboration the men had taken two decades to complete. Painlevé’s depiction allows us to see the elements of Calder's work that mark it as akin to Painlevé’s own interest in a modern experimental organicism as central to the so-called machine-age. Calder's work can be understood as similarly developing an avant-garde practice along the line between the bestiary of the natural historian and the bestiary of the modern life scientist.

scholarly journals Jaws of Platynereis dumerilii: Miniature Biogenic Structures with Hardness Properties Similar to Those of Crystalline Metals

JOM ◽  
2021 ◽  
Author(s):  
Luis Zelaya-Lainez ◽  
Giuseppe Balduzzi ◽  
Olaf Lahayne ◽  
Kyojiro N. Ikeda ◽  
Florian Raible ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Indentation Depth ◽  
Organic Matrix ◽  
Structure Property ◽  
Structural Protein ◽  
Inductively Coupled ◽  
Property Relations ◽  
Biogenic Structures ◽  
Platynereis Dumerilii ◽  
Bristle Worms

AbstractNanoindentation, laser ablation inductively coupled plasma mass spectroscopy and weighing ion-spiked organic matrix standards revealed structure-property relations in the microscopic jaw structures of a cosmopolitan bristle worm, Platynereis dumerilii. Hardness and elasticity values in the jaws’ tip region, exceeding those in the center region, can be traced back to more metal and halogen ions built into the structural protein matrix. Still, structure size appears as an even more relevant factor governing the hardness values measured on bristle worm jaws across the genera Platynereis, Glycera and Nereis. The square of the hardness scales with the inverse of the indentation depth, indicating a Nix-Gao size effect as known for crystalline metals. The limit hardness for the indentation depth going to infinity, amounting to 0.53 GPa, appears to be an invariant material property of the ion-spiked structural proteins likely used by all types of bristle worms. Such a metal-like biogenic material is a major source of bio-inspiration.

scholarly journals Picosecond time-resolved photon antibunching measures nanoscale exciton motion and the true number of chromophores

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Gordon J. Hedley ◽  
Tim Schröder ◽  
Florian Steiner ◽  
Theresa Eder ◽  
Felix J. Hofmann ◽  
...  
Keyword(s):  
Rational Design ◽  
Three Dimensional ◽  
Dna Origami ◽  
Fluorescent Nanoparticles ◽  
Time Resolved ◽  
Exciton Diffusion ◽  
Polymer Aggregates ◽  
True Number ◽  
Particle Level ◽  
Photon Antibunching

AbstractThe particle-like nature of light becomes evident in the photon statistics of fluorescence from single quantum systems as photon antibunching. In multichromophoric systems, exciton diffusion and subsequent annihilation occurs. These processes also yield photon antibunching but cannot be interpreted reliably. Here we develop picosecond time-resolved antibunching to identify and decode such processes. We use this method to measure the true number of chromophores on well-defined multichromophoric DNA-origami structures, and precisely determine the distance-dependent rates of annihilation between excitons. Further, this allows us to measure exciton diffusion in mesoscopic H- and J-type conjugated-polymer aggregates. We distinguish between one-dimensional intra-chain and three-dimensional inter-chain exciton diffusion at different times after excitation and determine the disorder-dependent diffusion lengths. Our method provides a powerful lens through which excitons can be studied at the single-particle level, enabling the rational design of improved excitonic probes such as ultra-bright fluorescent nanoparticles and materials for optoelectronic devices.

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