scholarly journals A strain-induced exciton transition energy shift in CdSe nanoplatelets: the impact of an organic ligand shell

Nanoscale ◽  
2017 ◽  
Vol 9 (45) ◽  
pp. 18042-18053 ◽  
Author(s):  
A. Antanovich ◽  
A. W. Achtstein ◽  
A. Matsukovich ◽  
A. Prudnikau ◽  
P. Bhaskar ◽  
...  
Keyword(s):  
Structural Properties ◽  
Transition Energy ◽  
Organic Ligand ◽  
Energy Shift ◽  
Exciton Transition ◽  
Zinc Blende ◽  
Ligand Shell ◽  
The Impact

We study the influence of surface passivating ligands on the optical and structural properties of zinc blende CdSe nanoplatelets.

Engineering Electronic Structure to Protect Phase Memory in Molecular Qubits by Minimising Orbital Angular Momentum

2018 ◽  
Author(s):  
Ana Maria Ariciu ◽  
David H. Woen ◽  
Daniel N. Huh ◽  
Lydia Nodaraki ◽  
Andreas Kostopoulos ◽  
...  
Keyword(s):  
Electron Spin ◽  
Quantum Coherence ◽  
Quantum Information Processing ◽  
Pulse Sequences ◽  
Grover Algorithm ◽  
Ligand Shell ◽  
Information Strategies ◽  
Spin Qubit ◽  
Molecular Spin ◽  
The Impact

Using electron spins within molecules for quantum information processing (QIP) was first proposed by Leuenberger and Loss (1), who showed how the Grover algorithm could be mapped onto a Mn12 cage (2). Since then several groups have examined two-level (S = ½) molecular spin systems as possible qubits (3-12). There has also been a report of the implementation of the Grover algorithm in a four-level molecular qudit (13). A major challenge is to protect the spin qubit from noise that causes loss of phase information; strategies to minimize the impact of noise on qubits can be categorized as corrective, reductive, or protective. Corrective approaches allow noise and correct for its impact on the qubit using advanced microwave pulse sequences (3). Reductive approaches reduce the noise by minimising the number of nearby nuclear spins (7-11), and increasing the rigidity of molecules to minimise the effect of vibrations (which can cause a fluctuating magnetic field via spin-orbit coupling) (9,11); this is essentially engineering the ligand shell surrounding the electron spin. A protective approach would seek to make the qubit less sensitive to noise: an example of the protective approach is the use of clock transitions to render spin states immune to magnetic fields at first order (12). Here we present a further protective method that would complement reductive and corrective approaches to enhancing quantum coherence in molecular qubits. The target is a molecular spin qubit with an effective 2S ground state: we achieve this with a family of divalent rare-earth molecules that have negligible magnetic anisotropy such that the isotropic nature of the electron spin renders the qubit markedly less sensitive to magnetic noise, allowing coherent spin manipulations even at room temperature. If combined with the other strategies, we believe this could lead to molecular qubits with substantial advantages over competing qubit proposals.<br>

scholarly journals Structural Properties of G,T-Parallel Duplexes

2010 ◽  
Vol 2010 ◽  
pp. 1-11 ◽  
Author(s):  
Anna Aviñó ◽  
Elena Cubero ◽  
Raimundo Gargallo ◽  
Carlos González ◽  
Modesto Orozco ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Structural Properties ◽  
Theoretical Calculations ◽  
Md Simulations ◽  
Theoretical Studies ◽  
Duplex Structure ◽  
Strong Stabilization ◽  
The Stability ◽  
The Impact

The structure of G,T-parallel-stranded duplexes of DNA carrying similar amounts of adenine and guanine residues is studied by means of molecular dynamics (MD) simulations and UV- and CD spectroscopies. In addition the impact of the substitution of adenine by 8-aminoadenine and guanine by 8-aminoguanine is analyzed. The presence of 8-aminoadenine and 8-aminoguanine stabilizes the parallel duplex structure. Binding of these oligonucleotides to their target polypyrimidine sequences to form the corresponding G,T-parallel triplex was not observed. Instead, when unmodified parallel-stranded duplexes were mixed with their polypyrimidine target, an interstrand Watson-Crick duplex was formed. As predicted by theoretical calculations parallel-stranded duplexes carrying 8-aminopurines did not bind to their target. The preference for the parallel-duplex over the Watson-Crick antiparallel duplex is attributed to the strong stabilization of the parallel duplex produced by the 8-aminopurines. Theoretical studies show that the isomorphism of the triads is crucial for the stability of the parallel triplex.

Molecular Dynamics Studies on the Growth and Structural Properties of Hydrogenated DLC Films

2008 ◽  
Vol 373-374 ◽  
pp. 108-112
Author(s):  
Yu Jun Zhang ◽  
Guang Neng Dong ◽  
Jun Hong Mao ◽  
You Bai Xie
Keyword(s):  
Molecular Dynamics ◽  
Structural Properties ◽  
Impact Energy ◽  
Frictional Coefficient ◽  
Carbon Films ◽  
Dynamics Simulation ◽  
Diamond Surface ◽  
Hydrogen Atoms ◽  
Molecular Configuration ◽  
The Impact

The novel frictional properties of hydrogenated DLC (Diamond-like Carbon) films have been reported for nearly ten years. But up to now, researchers still haven’t known the exact mechanism resulting in the super-low frictional performance of hydrogenated DLC films. Especially they have little knowledge on the molecular configuration and structural properties of these kinds of films. In this paper, CH3 radicals with different impact energies are selected as source species to deposit DLC films on diamond (100) by molecular dynamics simulation. Results show hydrogenated DLC films can be successfully obtained when impact energy is in an appropriate scope that is no less than 20eV. The depositing processes involve impinging diamond surface and bonding procedure. Some atoms, instead of bonding with substrate atoms, fly away from the diamond surface. Only suitable impact energy can improve the growth of the film. Within 30eV to 60eV, the maximum deposition ratio is attained. In addition, when carbon atoms act as the deposition sources, the deposition ratio is relatively higher. Furthermore, the authors find that species with higher concentration of carbon atoms in deposition sources lead to a better deposition rate. Carbon atoms are more reactive than hydrogen atoms. Then the relative densities of DLC films are calculated. The density curves indicate that the structures of the films vary obviously as the impact energy augments. The average relative density is generally monotone increase with the increment of impact energy. The hybridization of carbon atoms greatly affects the properties of hydrogenated DLC films. The transition between sp2 and sp3 will result in the graphitization and reduce the frictional coefficient when DLC films are used as tribo-pair in friction.

Structural properties of zinc-blende MnTe layers grown by hot-wall epitaxy

2001 ◽  
Vol 169-170 ◽  
pp. 325-330 ◽  
Author(s):  
T. Matsumoto ◽  
Y. Souno ◽  
H. Tatsuoka ◽  
Y. Nakanishi ◽  
H. Kuwabara
Keyword(s):  
Structural Properties ◽  
Zinc Blende ◽  
Hot Wall Epitaxy

EVALUATION OF THE OPERATIONAL WEAR OF THE SANDVIK CV117 CENTRIFUGAL CRUSHER

Tribologia ◽  
2020 ◽  
Vol 289 (1) ◽  
pp. 31-39
Author(s):  
Dominika GRYGIER
Keyword(s):  
Kinetic Energy ◽  
Structural Properties ◽  
Direct Contact ◽  
Operating Time ◽  
Full Scale ◽  
Impact Forces ◽  
The Impact ◽  
Macroscopic Analysis

The purpose of the study described in the work was to evaluate the operating wear of the SANDVIK CV117 centrifugal crusher working in the Melaphyre mine in Grzędy. The research was carried out on work elements, such as the lining assembly, rotor tips, shredder hammers, the directional bushing, and the distributor divider. All components had direct contact with the aggregate, and their operating time was about 1150 hours. The studies included a mine full scale observation, macroscopic analysis of the elements, and an assessment of the impact of exploitation on selected structural properties of the elements material. On the basis of the carried out analyses, it was concluded that the major problem faced by all the tested components is the simultaneous interaction of high friction and impact forces resulting from the kinetic energy of the accelerated grains of the material acquired from the rotor during operation of the crusher.

Characterization of the Organic Ligand Shell of Semiconductor Quantum Dots by Fluorescence Quenching Experiments

ACS Nano ◽  
2011 ◽  
Vol 5 (10) ◽  
pp. 8115-8123 ◽  
Author(s):  
Klaus Boldt ◽  
Sebastian Jander ◽  
Kathrin Hoppe ◽  
Horst Weller
Keyword(s):  
Quantum Dots ◽  
Fluorescence Quenching ◽  
Organic Ligand ◽  
Semiconductor Quantum Dots ◽  
Ligand Shell

scholarly journals Changes in dissolved iron deposition to the oceans driven by human activity: a 3-D global modelling study

2015 ◽  
Vol 12 (5) ◽  
pp. 3943-3990
Author(s):  
S. Myriokefalitakis ◽  
N. Daskalakis ◽  
N. Mihalopoulos ◽  
A. R. Baker ◽  
A. Nenes ◽  
...  
Keyword(s):  
Air Quality ◽  
Transport Model ◽  
Organic Ligand ◽  
Photochemical Reactions ◽  
Anthropogenic Emissions ◽  
Spatial And Temporal Variability ◽  
Deposition Flux ◽  
Chemical Transport Model ◽  
The Future ◽  
The Impact

Abstract. The global atmospheric iron (Fe) cycle is parameterized in the global 3-D chemical transport model TM4-ECPL to simulate the proton- and the organic ligand-promoted mineral Fe dissolution as well as the aqueous-phase photochemical reactions between the oxidative states of Fe(III/II). Primary emissions of total (TFe) and dissolved (DFe) Fe associated with dust and combustion processes are also taken into account. TFe emissions are calculated to amount to ~35 Tg Fe yr−1. The model reasonably simulates the available Fe observations, supporting the reliability of the results of this study. Accounting for proton- and organic ligand-promoted Fe-dissolution in present-day TM4-ECPL simulations, the total Fe-dissolution is calculated to be ~0.163 Tg Fe yr−1 that accounts for up to ~50% of the calculated total DFe emissions. The atmospheric burden of DFe is calculated to be ~0.012 Tg Fe. DFe deposition presents strong spatial and temporal variability with an annual deposition flux ~0.489 Tg Fe yr−1 from which about 25% (~0.124 Tg Fe yr−1) are deposited over the ocean. The impact of air-quality on Fe deposition is studied by performing sensitivity simulations using preindustrial (year 1850), present (year 2008) and future (year 2100) emission scenarios. These simulations indicate that an increase (~2 times) in Fe-dissolution may have occurred in the past 150 years due to increasing anthropogenic emissions and thus atmospheric acidity. On the opposite, a decrease (~2 times) of Fe-dissolution is projected for near future, since atmospheric acidity is expected to be lower than present-day due to air-quality regulations of anthropogenic emissions. The organic ligand contribution to Fe dissolution shows inverse relationship to the atmospheric acidity thus its importance has decreased since the preindustrial period but is projected to increase in the future. The calculated changes also show that the atmospheric DFe supply to High-Nutrient-Low-Chlorophyll oceanic areas (HNLC) characterized by Fe scarcity, has increased (~50%) since the preindustrial period. However, the DFe deposition flux is expected to decrease (~30%) to almost preindustrial levels over the Northern Hemisphere HNLC oceanic regions in the future. Significant reductions of ~20% over the Southern Ocean and the remote tropical Pacific Ocean are also projected which can further limit the primary productivity over HNLC waters.

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