scholarly journals Algebraic Theory of Molecules

Author(s):  
F. Iachello ◽  
R. D. Levine

Algebraic Theory of Molecules presents a fresh look at the mathematics of wave functions that provide the theoretical underpinnings of molecular spectroscopy. Written by renowned authorities in the field, the book demonstrates the advantages of algebraic theory over the more conventional geometric approach to developing the formal quantum mechanics inherent in molecular spectroscopy. Many examples are provided that compare the algebraic and geometric methods, illustrating the relationship between the algebraic approach and current experiments. The authors develop their presentation from a basic level so as to enable newcomers to enter the field while providing enough details and concrete examples to serve as a reference for the expert. Chemical physicists, physical chemists, and spectroscopists will want to read this exciting new approach to molecular spectroscopy.

2020 ◽  
Vol 30 (Supplement_2) ◽  
Author(s):  
A C Martins ◽  
P Francisco

Abstract Introduction Recognizing that AT service characteristics, including knowledge and reasoning of providers, play a potential role in the appropriated selection and training, with impact on the psychosocial domains of QoL. In Portugal, AT services are detected to be ineffective concerning evaluation, recommendation, advocacy, training and outcome measuring, what could be a reason for these findings. Objectives To investigate the relationship between AT services characteristics and psychosocial impact of the wheelchairs on users QoL to get insights to new approach models in physiotherapy. Methodology Procedures included answering to self-administered questionnaires at their own. The dependent variable was the psychosocial impact of assistive devices (PIADS) and the independent variables were satisfaction with AT (QUEST) and AT service characteristics. Results Participants were 184 wheelchair users for more than one year with diverse diagnosis; age M = 37.3 years, recruited at physiotherapy/rehabilitation settings in Portugal. Wheelchair users are more satisfied with devices than with AT services. Correlations between psychosocial impact of wheelchair are moderate regarding the satisfaction of device dimension, measured by QUEST. No corrections were found to satisfaction with service dimension Manual wheelchair users scored lower psychosocial impact than motorized wheelchair users and that difference was statistically significant. Conclusion PT should be aware of the newest high technology devices introduced on the market, payment sources and state AT programs as well as destigmatize dependence associated to AT. We got significant insights to AT field and to the development of PT curriculum; PT students need more than the basic level of knowledge and training they achieved at school to feel prepared to provide AT services. After graduation, PTs need continuing education on AT. Strategies are discussed on this report.


2016 ◽  
Vol 13 (01) ◽  
pp. 1550129 ◽  
Author(s):  
Newton da Costa ◽  
Joseph Kouneiher

The main purpose of this paper is to present a new approach to logic or what we will call superlogic. This approach constitutes a new way of looking at the connection between quantum mechanics and logic. It is a geometrization of the quantum logic. Note that this superlogic is not distributive reflecting a good propriety to describe quantum mechanics, non-commutative spaces and contains a nilpotent element.


2017 ◽  
Vol 8 (1) ◽  
pp. 22-48 ◽  
Author(s):  
Iain Mackinnon

This article employs a new approach to studying internal colonialism in northern Scotland during the 18th and 19th centuries. A common approach to examining internal colonial situations within modern state territories is to compare characteristics of the internal colonial situation with attested attributes of external colonial relations. Although this article does not reject the comparative approach, it seeks to avoid criticisms that this approach can be misleading by demonstrating that promoters and managers of projects involving land use change, territorial dispossession and industrial development in the late modern Gàidhealtachd consistently conceived of their work as projects of colonization. It further argues that the new social, cultural and political structures these projects imposed on the area's indigenous population correspond to those found in other colonial situations, and that racist and racialist attitudes towards Gaels of the time are typical of those in colonial situations during the period. The article concludes that the late modern Gàidhealtachd has been a site of internal colonization where the relationship of domination between colonizer and colonized is complex, longstanding and occurring within the imperial state. In doing so it demonstrates that the history and present of the Gaels of Scotland belongs within the ambit of an emerging indigenous research paradigm.


Author(s):  
Frank S. Levin

The subject of Chapter 8 is the fundamental principles of quantum theory, the abstract extension of quantum mechanics. Two of the entities explored are kets and operators, with kets being representations of quantum states as well as a source of wave functions. The quantum box and quantum spin kets are specified, as are the quantum numbers that identify them. Operators are introduced and defined in part as the symbolic representations of observable quantities such as position, momentum and quantum spin. Eigenvalues and eigenkets are defined and discussed, with the former identified as the possible outcomes of a measurement. Bras, the counterpart to kets, are introduced as the means of forming probability amplitudes from kets. Products of operators are examined, as is their role underpinning Heisenberg’s Uncertainty Principle. A variety of symbol manipulations are presented. How measurements are believed to collapse linear superpositions to one term of the sum is explored.


2021 ◽  
Vol 1744 (3) ◽  
pp. 032176
Author(s):  
Man Zhang ◽  
Yunfei Wu ◽  
Hongyun Cui ◽  
Ju Cheng

2021 ◽  
Vol 2021 (8) ◽  
Author(s):  
Sotaro Sugishita

Abstract We consider entanglement of first-quantized identical particles by adopting an algebraic approach. In particular, we investigate fermions whose wave functions are given by the Slater determinants, as for singlet sectors of one-matrix models. We show that the upper bounds of the general Rényi entropies are N log 2 for N particles or an N × N matrix. We compute the target space entanglement entropy and the mutual information in a free one-matrix model. We confirm the area law: the single-interval entropy for the ground state scales as $$ \frac{1}{3} $$ 1 3 log N in the large N model. We obtain an analytical $$ \mathcal{O}\left({N}^0\right) $$ O N 0 expression of the mutual information for two intervals in the large N expansion.


Atmosphere ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 12
Author(s):  
Yulia Ivanova ◽  
Anton Kovalev ◽  
Vlad Soukhovolsky

The paper considers a new approach to modeling the relationship between the increase in woody phytomass in the pine forest and satellite-derived Normalized Difference Vegetation Index (NDVI) and Land Surface Temperature (LST) (MODIS/AQUA) data. The developed model combines the phenological and forest growth processes. For the analysis, NDVI and LST (MODIS) satellite data were used together with the measurements of tree-ring widths (TRW). NDVI data contain features of each growing season. The models include parameters of parabolic approximation of NDVI and LST time series transformed using principal component analysis. The study shows that the current rate of TRW is determined by the total values of principal components of the satellite indices over the season and the rate of tree increment in the preceding year.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Lara B. Anderson ◽  
James Gray ◽  
Magdalena Larfors ◽  
Matthew Magill ◽  
Robin Schneider

Abstract Heterotic compactifications on Calabi-Yau threefolds frequently exhibit textures of vanishing Yukawa couplings in their low energy description. The vanishing of these couplings is often not enforced by any obvious symmetry and appears to be topological in nature. Recent results used differential geometric methods to explain the origin of some of this structure [1, 2]. A vanishing theorem was given which showed that the effect could be attributed, in part, to the embedding of the Calabi-Yau manifolds of interest inside higher dimensional ambient spaces, if the gauge bundles involved descended from vector bundles on those larger manifolds. In this paper, we utilize an algebro-geometric approach to provide an alternative derivation of some of these results, and are thus able to generalize them to a much wider arena than has been considered before. For example, we consider cases where the vector bundles of interest do not descend from bundles on the ambient space. In such a manner we are able to highlight the ubiquity with which textures of vanishing Yukawa couplings can be expected to arise in heterotic compactifications, with multiple different constraints arising from a plethora of different geometric features associated to the gauge bundle.


Author(s):  
Talat Körpınar ◽  
Yasin Ünlütürk

AbstractIn this research, we study bienergy and biangles of moving particles lying on the surface of Lorentzian 3-space by using their energy and angle values. We present the geometrical characterization of bienergy of the particle in Darboux vector fields depending on surface. We also give the relationship between bienergy of the surface curve and bienergy of the elastic surface curve. We conclude the paper by providing bienergy-curve graphics for different cases.


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