scholarly journals PhysChem: A New Physical Chemistry Journal

Physchem ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 1-3
Author(s):  
Vincenzo Barone ◽  
Sergei Manzhos ◽  
Jacinto Sá
Keyword(s):  
Physical Chemistry ◽  
Chemical Reactions ◽  
Atomic Level ◽  
Chemistry Journal

Physical chemistry is broadly defined as the branch of chemistry devoted to the study of how matter behaves on a molecular and atomic level and how chemical reactions occur [...]

scholarly journals Ronald George Wreyford Norrish, 9 November 1897 - 7 June 1978

1981 ◽  
Vol 27 ◽  
pp. 379-424 ◽  
Keyword(s):  
Physical Chemistry ◽  
Chemical Reactions ◽  
Nobel Prize ◽  
Flash Photolysis ◽  
Polymer Chemistry ◽  
World War ◽  
Entire Life ◽  
Chain Reactions ◽  
The University

Ronald George Wreyford Norrish was born in Cambridge on 9 November 1897 and died in Addenbrooke’s Hospital there on 7 June 1978. He was educated at the Perse School and then at Emmanuel College, Cambridge, and apart from his service in World War spent his entire life in Cambridge. For nearly 30 years he was Professor of Physical Chemistry in the University. He was one of the pioneers of photochemistry and also carried out much research on chain reactions and polymer chemistry. For his work in developing flash photolysis as a means of studying rapid chemical reactions he shared the Nobel Prize for Chemistry in his seventieth year.

Processing Video Images of Chemical Reactions

1990 ◽  
Vol 48 (1) ◽  
pp. 538-539
Author(s):  
Eyring LeRoy ◽  
W.J. de Ruijter
Keyword(s):  
Electron Microscope ◽  
Chemical Reactions ◽  
Chemical Reactivity ◽  
Scientific Information ◽  
Chemical Change ◽  
Atomic Level ◽  
Storage Medium ◽  
Video Images ◽  
Transmission Electron ◽  
Pertinent Information

The high-resolution transmission electron microscope is unique in its capacity to provide direct images of bulk matter at the atomic level. This suggests the electron microscope as a nanochemical laboratory in which elementary reaction mechanisms can be observed and deciphered. The nature, disposition, and evolution of defects, the agents of chemical change, must be studied intimately if the fundamentals of chemical reactivity in solids are to be understood fully. Chemical change during microscopical observation is inevitable since alterations in the electronic associations of the atoms are produced by the electron beam. For a chemist this presents an extraordinary opportunity for investigating the atomic-level mechanism of a chemical reaction.Chemical reactions observed at near atomic resolution can be recorded on videotape at the rate of 30 images per second. Since the onset, extent and rapidity of a reaction varies over many orders of magnitude and is not predictable it is sometimes necessary to record for hours. The videotape provides a convenient storage medium for this immense quantity of information. The tapes can then be edited for those stretches bearing pertinent information and can be processed as needed. The purpose may simply be clear communication of scientific information to peers or more extensive processing may be desired for pedagogical use.

Charles S. Barrett: X-Ray Metallurgist — An Informal Portrait

1987 ◽  
Vol 2 (3) ◽  
pp. 163-175
Author(s):  
R. N. Rose
Keyword(s):  
Physical Chemistry ◽  
Phase Transformation ◽  
Low Temperature ◽  
First Principles ◽  
Atomic Level ◽  
X Ray Diffraction ◽  
Wide Audience ◽  
X Ray

Charles Barrett's work in phase transformation at the atomic level helped redefine the underpinnings of the science and practice of metallurgy. His work in low temperature physical chemistry has extended its range. And, perhaps more than anyone else, as a teacher and author, he has helped introduce the technique of X-ray diffraction to the present generations of practicing metallurgists.The relevance of his contributions is demonstrated by the continuing utility of his widely translated metallurgical text, Structure of Metals, which, when it first appeared, made the understanding of metallurgy at the atomic level accessible to a wide audience. Today this book has become a compendium of first principles.

scholarly journals Evolution of Flavylium-Based Color Systems in Plants: What Physical Chemistry Can Tell Us

2021 ◽  
Vol 22 (8) ◽  
pp. 3833
Author(s):  
Fernando Pina ◽  
Alfonso Alejo-Armijo ◽  
Adelaide Clemente ◽  
Johan Mendoza ◽  
André Seco ◽  
...  
Keyword(s):  
Physical Chemistry ◽  
Intermolecular Interactions ◽  
Chemical Reactions ◽  
Supramolecular Structures ◽  
Stopped Flow ◽  
Thermodynamics And Kinetics ◽  
Commelina Communis ◽  
Color System

Anthocyanins are the basis of the color of angiosperms, 3-deoxyanthocyanins and sphagnorubin play the same role in mosses and ferns, and auronidins are responsible for the color in liverworts. In this study, the color system of cyanidin-3-O-glucoside (kuromanin) as a representative compound of simpler anthocyanins was fully characterized by stopped flow. This type of anthocyanin cannot confer significant color to plants without intra- or intermolecular interactions, complexation with metals or supramolecular structures as in Commelina communis. The anthocyanin’s color system was compared with those of 3-deoxyanthocyanins and riccionidin A, the aglycone of auronidins. The three systems follow the same sequence of chemical reactions, but the respective thermodynamics and kinetics are dramatically different.

scholarly journals Validation of ligands in macromolecular structures determined by X-ray crystallography

2018 ◽  
Vol 74 (3) ◽  
pp. 228-236 ◽  
Author(s):  
Oliver S. Smart ◽  
Vladimír Horský ◽  
Swanand Gore ◽  
Radka Svobodová Vařeková ◽  
Veronika Bendová ◽  
...  
Keyword(s):  
Physical Chemistry ◽  
Electron Density ◽  
Data Bank ◽  
Atomic Level ◽  
Biological Macromolecules ◽  
X Ray ◽  
Validation Metrics ◽  
X Ray Crystallography ◽  
Small Molecule Ligands

Crystallographic studies of ligands bound to biological macromolecules (proteins and nucleic acids) play a crucial role in structure-guided drug discovery and design, and also provide atomic level insights into the physical chemistry of complex formation between macromolecules and ligands. The quality with which small-molecule ligands have been modelled in Protein Data Bank (PDB) entries has been, and continues to be, a matter of concern for many investigators. Correctly interpreting whether electron density found in a binding site is compatible with the soaked or co-crystallized ligand or represents water or buffer molecules is often far from trivial. The Worldwide PDB validation report (VR) provides a mechanism to highlight any major issues concerning the quality of the data and the model at the time of deposition and annotation, so the depositors can fix issues, resulting in improved data quality. The ligand-validation methods used in the generation of the current VRs are described in detail, including an examination of the metrics to assess both geometry and electron-density fit. It is found that the LLDF score currently used to identify ligand electron-density fit outliers can give misleading results and that better ligand-validation metrics are required.

An automated system that assists in the generation of document indexes

1996 ◽  
Vol 2 (2) ◽  
pp. 137-160 ◽  
Author(s):  
JULIA HODGES ◽  
SHIYUN YIE ◽  
RAY REIGHART ◽  
LOIS BOGGESS
Keyword(s):  
Physical Chemistry ◽  
Natural Language Processing ◽  
Language Processing ◽  
Recall Rate ◽  
Automated System ◽  
Journal Articles ◽  
Future Work ◽  
Chemistry Journal ◽  
Precision Rate ◽  
Recent Evaluation

In this article, we describe AIMS (Assisted Indexing at Mississippi State), a system intended to aid human document analysts in the assignment of indexes to physical chemistry journal articles. The two major components of AIMS are a natural language processing (NLP) component and an index generation (IG) component. We provide an overview of what each of these components does and how it works. We also present the results of a recent evaluation of our system in terms of recall and precision. The recall rate is the proportion of the ‘correct’ indexes (i.e. those produced by human document analysts) generated by AIMS. The precision rate is the proportion of the generated indexes that is correct. Finally, we describe some of the future work planned for this project.

Theories of Molecular Reaction Dynamics

2018 ◽  
Author(s):  
Niels E. Henriksen ◽  
Flemming Y. Hansen
Keyword(s):  
Quantum Mechanics ◽  
Statistical Mechanics ◽  
Chemical Reactions ◽  
Cross Sections ◽  
Reaction Dynamics ◽  
Reaction Cross ◽  
Atomic Level ◽  
Phase Dynamics ◽  
Molecular Reaction ◽  
Reaction Cross Sections

This book deals with a central topic at the interface of chemistry and physics—the understanding of how the transformation of matter takes place at the atomic level. Building on the laws of physics, the book focuses on the theoretical framework for predicting the outcome of chemical reactions. The style is highly systematic with attention to basic concepts and clarity of presentation. Molecular reaction dynamics is about the detailed atomic-level description of chemical reactions. Based on quantum mechanics and statistical mechanics or, as an approximation, classical mechanics, the dynamics of uni- and bimolecular elementary reactions are described. The first part of the book is on gas-phase dynamics and it features a detailed presentation of reaction cross-sections and their relation to a quasi-classical as well as a quantum mechanical description of the reaction dynamics on a potential energy surface. Direct approaches to the calculation of the rate constant that bypasses the detailed state-to-state reaction cross-sections are presented, including transition-state theory, which plays an important role in practice. The second part gives a comprehensive discussion of basic theories of reaction dynamics in condensed phases, including Kramers and Grote–Hynes theory for dynamical solvent effects. Examples and end-of-chapter problems are included in order to illustrate the theory and its connection to chemical problems. The book has ten appendices with useful details, for example, on adiabatic and non-adiabatic electron-nuclear dynamics, statistical mechanics including the Boltzmann distribution, quantum mechanics, stochastic dynamics and various coordinate transformations including normal-mode and Jacobi coordinates.

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