Rainbows, supernumerary rainbows and interference effects in the angular scattering of chemical reactions: an investigation using Heisenberg's S matrix programme

Earlier stochastic analyses of chemical reactions have provided formal solutions which are unsuitable for most purposes in that they are expressed in terms of complex algebraic functions. Normal approximations are derived here for solutions to a variety of reactions. Using these, it is possible to investigate the level at which the classical deterministic solutions become inadequate. This is important in fields such as radioimmunoassay.

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Facile preparation of polyoxometalate nanoparticles via a solid-state chemical reaction for aerobic oxidative desulfurization catalysis

Dalton Transactions ◽

10.1039/d1dt01695d ◽

2021 ◽

Author(s):

Hang Yu ◽

Wenwen Bu ◽

Zijia Wang ◽

Zhuoyue Zhao ◽

Mehwish Jadoon ◽

...

Keyword(s):

Solid State ◽

Silver Nitrate ◽

Chemical Reaction ◽

Solid State Reaction ◽

Room Temperature ◽

Oxidative Desulfurization ◽

Solid State Reaction Method ◽

Reaction Method ◽

State Chemical ◽

Facile Preparation

Polyoxometalate nanoparticles were synthesized via a concise solid-state reaction method by directly grinding silver nitrate and the polyoxometalate (NH4)5H6PMo4V8O40 at room temperature without the assistance of a surfactant.

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Mapping the Space of Chemical Reactions using Attention-Based Neural Networks

10.26434/chemrxiv.9897365.v3 ◽

2020 ◽

Author(s):

Philippe Schwaller ◽

Daniel Probst ◽

Alain C. Vaucher ◽

Vishnu H Nair ◽

David Kreutter ◽

...

Keyword(s):

Neural Networks ◽

Reaction Center ◽

Chemical Reactions ◽

Chemical Reaction ◽

Classification Accuracy ◽

Similarity Searching ◽

Reaction Space ◽

Fine Grained ◽

Visual Clustering ◽

Better Than

<div><div><div><p>Organic reactions are usually assigned to classes grouping reactions with similar reagents and mechanisms. Reaction classes facilitate communication of complex concepts and efficient navigation through chemical reaction space. However, the classification process is a tedious task, requiring the identification of the corresponding reaction class template via annotation of the number of molecules in the reactions, the reaction center and the distinction between reactants and reagents. In this work, we show that transformer-based models can infer reaction classes from non-annotated, simple text-based representations of chemical reactions. Our best model reaches a classification accuracy of 98.2%. We also show that the learned representations can be used as reaction fingerprints which capture fine-grained differences between reaction classes better than traditional reaction fingerprints. The unprecedented insights into chemical reaction space enabled by our learned fingerprints is illustrated by an interactive reaction atlas providing visual clustering and similarity searching. </p><p><br></p><p>Code: https://github.com/rxn4chemistry/rxnfp</p><p>Tutorials: https://rxn4chemistry.github.io/rxnfp/</p><p>Interactive reaction atlas: https://rxn4chemistry.github.io/rxnfp//tmaps/tmap_ft_10k.html</p></div></div></div>

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The kinetics of the photo-induced solid-state chemical reaction in Ag/As33S67bilayers and its reaction products

Philosophical Magazine B ◽

10.1080/13642819908206794 ◽

1999 ◽

Vol 79 (2) ◽

pp. 223-237 ◽

Cited By ~ 24

Author(s):

T. Wagner ◽

E. Márquez ◽

J. Fernández-Pena ◽

J. M. González-Leal ◽

P. J. S. Ewen ◽

...

Keyword(s):

Solid State ◽

Chemical Reaction ◽

Reaction Products ◽

State Chemical ◽

Solid State Chemical Reaction ◽

Kinetics Of

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Mass transfer with complex reversible chemical reactions—I. Single reversible chemical reaction

Chemical Engineering Science ◽

10.1016/0009-2509(89)85163-2 ◽

1989 ◽

Vol 44 (10) ◽

pp. 2295-2310 ◽

Cited By ~ 64

Author(s):

G.F. Versteeg ◽

J.A.M. Kuipers ◽

F.P.H. Van Beckum ◽

W.P.M. Van Swaaij

Keyword(s):

Mass Transfer ◽

Chemical Reactions ◽

Chemical Reaction ◽

Reversible Chemical Reaction

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Kinetic study of key species and reactions of atmospheric pressure pulsed corona discharge in humid air

Plasma Science and Technology ◽

10.1088/2058-6272/ac4693 ◽

2021 ◽

Author(s):

Yongkang Peng ◽

Xiaoyue Chen ◽

Yeqiang Deng ◽

Lan Lei ◽

Zhan Haoyu ◽

...

Keyword(s):

Chemical Reactions ◽

Chemical Reaction ◽

Atmospheric Pressure ◽

Discharge Plasma ◽

Reaction Rates ◽

Global Model ◽

Discharge Process ◽

Humid Air ◽

Pressure Discharge ◽

Atmospheric Pressure Discharge

Abstract The traditional corona discharge fluid model considers only electrons, positive and negative ions, and the discharge parameters are determined using the simplified weighting method involving the partial pressure ratio. Atmospheric pressure discharge plasma in humid air involves three main neutral gas molecule types: N2, O2, and H2O(g). However, in these conditions, the discharge process involves many types of particles and chemical reactions, and the charge and substance transfer processes are complex. At present, the databases of plasma chemical reaction equations are still expanding based on scholarly research. In this study, we examined the key particles and chemical reactions that substantially influence plasma characteristics. In summarizing the chemical reaction model for the discharge process of N2–O2–H2O(g) mixed gases, 65 particle types and 673 chemical reactions were investigated. On this basis, a global model of atmospheric pressure humid air discharge plasma was developed, with a focus on the variation of charged particles densities and chemical reaction rates with time under the excitation of a 0–200 Td pulsed electric field. Particles with a density greater than 1% of the electron density were classified as key particles. For such particles, the top ranking generation or consumption reactions (i.e., where the sum of their rates was greater than 95% of the total rate of the generation or consumption reactions) were classified as key chemical reactions On the basis of the key particles and reactions identified, a simplified global model was derived. A comparison of the global model with the simplified global model in terms of the model parameters, particle densities, reaction rates (with time), and calculation efficiencies demonstrated that both models can adequately identify the key particles and chemical reactions reflecting the chemical process of atmospheric pressure discharge plasma in humid air. Thus, by analyzing the key particles and chemical reaction pathways, the charge and substance transfer mechanism of atmospheric pressure pulse discharge plasma in humid air was revealed, and the mechanism underlying water vapor molecules’ influence on atmospheric pressure air discharge was elucidated.

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Chemical Reaction Kinetics in Solution

Liquids, Solutions, and Interfaces ◽

10.1093/oso/9780195094329.003.0011 ◽

2004 ◽

Author(s):

W. Ronald Fawcett

Keyword(s):

Reaction Kinetics ◽

Chemical Reactions ◽

Chemical Reaction ◽

Physical Property ◽

Theoretical Description ◽

Time Range ◽

Chemical Changes ◽

Elementary Reactions ◽

Chemical Reaction Kinetics ◽

Liquid Solutions

The kinetics of chemical reactions were first studied in liquid solutions. These experiments involved mixing two liquids and following the change in the concentration of a reactant or product with time. The concentration was monitored by removing a small sample of the solution and stopping the reaction, for example, by rapidly lowering the temperature, or by following a physical property of the system in situ, for example, its color. Although the experiments were initially limited to slow reactions, they established the basic laws governing the rate at which chemical changes occur. The variables considered included the concentrations of the reactants and of the products, the temperature, and the pressure. Thus, the reacting system was examined using the variables normally considered for a system at equilibrium. Most reactions were found to be complex, that is, to be made up of several elementary steps which involved one or two reactants. As the fundamental concepts of chemical kinetics developed, there was a strong interest in studying chemical reactions in the gas phase. At low pressures the reacting molecules in a gaseous solution are far from one another, and the theoretical description of equilibrium thermodynamic properties was well developed. Thus, the kinetic theory of gases and collision processes was applied first to construct a model for chemical reaction kinetics. This was followed by transition state theory and a more detailed understanding of elementary reactions on the basis of quantum mechanics. Eventually, these concepts were applied to reactions in liquid solutions with consideration of the role of the non-reacting medium, that is, the solvent. An important turning point in reaction kinetics was the development of experimental techniques for studying fast reactions in solution. The first of these was based on flow techniques and extended the time range over which chemical changes could be observed from a few seconds down to a few milliseconds. This was followed by the development of a variety of relaxation techniques, including the temperature jump, pressure jump, and electrical field jump methods. In this way, the time for experimental observation was extended below the nanosecond range.

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