Small is different

2021 ◽  
pp. 81-93
Author(s):  
Adrian P Sutton
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Catalytic Activity ◽  
Giant Magnetoresistance ◽  
Energy Levels ◽  
Exclusion Principle ◽  
Thermodynamic Quantities ◽  
Discrete Energy ◽  
Size Dependent ◽  
The World

As the size of a material decreases to the nanoscale its properties become size-dependent. This is the world of nanoscience and nanotechnology. At the nanoscale the crystal structure may change and thermodynamic quantities such as the melting point also change. Changes in the catalytic activity and colour of nanoparticles suspended in a liquid indicate changes to the electronic structure. Quantum dots have discrete energy levels that can be modelled with the particle-in-a-box model. Excitons may be created in them using optical illumination, and their decay leads to fluorescence with distinct colours. The classical and quantum origins of magnetism are discussed. The origin of magnetoresistance in a ferromagnet is described and related to the exclusion principle. The origin of the giant magnetoresistance effect and its exploitation in nanotechnology is outlined.

scholarly journals Revealing the Target Electronic Structure with Under-Threshold RABBIITT

Atoms ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 66
Author(s):  
Anatoli Kheifets
Keyword(s):  
Electronic Structure ◽  
Bound States ◽  
Energy Levels ◽  
Laser Frequency ◽  
Target Atom ◽  
Oscillator Strengths ◽  
Ionization Threshold ◽  
Discrete Energy ◽  
Two Photon

The process of reconstruction of attosecond beating by interference of two-photon transitions (RABBITT) reveals the target atom electronic structure when one of the transitions proceeds from below the ionization threshold. Such an under-threshold RABBITT resonates with the target bound states and thus maps faithfully the discrete energy levels and the corresponding oscillator strengths. We demonstrate this sensitivity by considering the Ne atom driven by the combination of the XUV and IR pulses at the fundmanetal laser frequency in the 800 and 1000 nm ranges.

Structural/Property Relationships for Optical Materials

1993 ◽  
Vol 329 ◽  
Author(s):  
Vivien D.
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Electronic Structure ◽  
Chemical Composition ◽  
Field Strength ◽  
Optical Materials ◽  
Site Occupancy ◽  
Laser Materials ◽  
Crystal Field Strength ◽  
The Matrix

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.

scholarly journals Trustworthiness of Flexible Rockfall Protection Systems

Geosciences ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 197
Author(s):  
Axel Volkwein ◽  
Marcel Fulde ◽  
Ingvar Krieger Hauksson
Keyword(s):  
Energy Levels ◽  
Protection System ◽  
Protection Systems ◽  
The World ◽  
Rockfall Protection

Flexible rockfall protection systems are an effective and efficient remedy against rockfalls with energy levels between 100 and up to 10,000 kJ. Although they are heavily in use all around the world, the backgrounds that guarantee a reliable barrier are not well known by most of intervening agents and users. This contribution gives some insights on how to judge the capability, reliability, and trustworthiness of a rockfall protection system. The paper focuses on three strategies to build up confidence and trustworthiness regarding the barrier’s correct or expected functioning: testing, certification, and how to assess adaptions of standard barrier systems.

scholarly journals Crystal structure of a complement factor D mutant expressing enhanced catalytic activity.

1995 ◽  
Vol 270 (52) ◽  
pp. 31414
Author(s):  
Sunghee Kim ◽  
Sthanam V.L. Narayana ◽  
John E. Volanakis
Keyword(s):  
Crystal Structure ◽  
Catalytic Activity ◽  
Complement Factor

Electronic structure modulation of NiS2 by transition metal doping for accelerating the hydrogen evolution reaction

2019 ◽  
Vol 7 (9) ◽  
pp. 4971-4976 ◽  
Author(s):  
Tongtong Wang ◽  
Xiaosong Guo ◽  
Jingyan Zhang ◽  
Wen Xiao ◽  
Pinxian Xi ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Catalytic Activity ◽  
Transition Metal ◽  
Hydrogen Evolution Reaction ◽  
Systematic Study ◽  
First Principles ◽  
Transition Metal Doping ◽  
First Principles Calculations ◽  
Structure Modulation ◽  
Metal Doped

We give a systematic study of the HER catalytic activity of transition metal doped NiS2 by first principles calculations and experiments.

Reactivities of platinum subnanocluster catalysts for the oxidation reaction of alcohols

RSC Advances ◽  
2015 ◽  
Vol 5 (122) ◽  
pp. 100693-100696 ◽  
Author(s):  
Masaki Takahashi ◽  
Takane Imaoka ◽  
Kimihisa Yamamoto
Keyword(s):  
Catalytic Activity ◽  
Oxidation Reaction ◽  
Alcohol Oxidation ◽  
Template Method ◽  
Size Dependent

The size-dependent catalytic activity for alcohol oxidation was investigated using the platinum subnanoclusters synthesized by the dendrimer template method.

Polymorphism and the influence of crystal structure on the luminescence of the opto-electronic material 4,4′-bis(9-carbazolyl)biphenyl

CrystEngComm ◽  
2014 ◽  
Vol 16 (33) ◽  
pp. 7621-7625 ◽  
Author(s):  
Cody J. Gleason ◽  
Jordan M. Cox ◽  
Ian M. Walton ◽  
Jason B. Benedict
Keyword(s):  
Crystal Structure ◽  
Electronic Structure ◽  
Electronic Material ◽  
Single Crystal ◽  
Charge Transport ◽  
Luminescent Properties ◽  
Electronic Structure Calculations ◽  
Electronic Charge ◽  
Single Crystal Structures ◽  
Structure Calculations

Single crystal structures, luminescent properties and electronic structure calculations of three polymorphs of the opto-electronic charge transport material 4,4′-bis(9-carbazolyl)biphenyl.

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