bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dynamical Theory I. General Theory
Authors: Peng L -M , Dudarev S L , Whelan M J 
Published: November 2023

Abstract
Elastic scattering of high-energy electrons is described by the one-particle SchroÖ-dinger equation (1.17). This equation was derived using the Born–Oppenheimer approximation and the independent electron approximation. The Born–Oppen-heimer approximation states that it is possible to separate the degrees of freedom corresponding to the motion of electrons and ions in the material. Since the mass of an electron is about four orders of magnitude smaller than that of an ion, typical electron velocities are much higher than those of ions. Since ions move much more slowly than electrons, we can assume that at any moment of time the electron system remains in its ground state corresponding to the instantaneous positions of ions (see for example (Ashcroft and Mermin, 1976)). The coordinates of ions enter (1.17) as parameters determining the form of the potential energy term V (r) in this equation.
Dynamical Theory Iii. Reflection High-Energy Electron Diffraction
Authors: Peng L -M , Dudarev S L , Whelan M J 
Published: November 2023

Abstract
In their pioneering experiments leading to the independent and simultaneous discovery with Thomson and Reid (Thomson and Reid, 1927) of the phenomenon of electron diffraction, Davisson and Germer (Davisson and Germer, 1927) used the reflection geometry of diffraction and investigated how the intensities of reflected beams vay as a function of the primary beam energy.
Resonance Effects In Transmission And Reflection High-Energy Electron Diffraction
Authors: Peng L -M , Dudarev S L , Whelan M J 
Published: November 2023

Abstract
Resonance scattering of electrons is probably one of the most remarkable and fundamental phenomena known in electron diffraction. In its simplest manifestation resonance diffraction gives rise to a dramatic increase of the reflectivity of a flat crystal surface that occurs in a certain relatively narrow range of angles of incidence. A typical reflection electron diffraction pattern (of which Fig. 6.1 is an example), in addition to Bragg diffraction spots, also shows a system of intersecting parabolic and semi-circular Kikuchi lines. These lines are associated with resonance scattering of electrons. Both the shape of resonance Kikuchi lines and their brightness make them very distinct and unusual, and the reason why they appear in a diffraction pattern requires a careful and thorough examination. Understanding the nature of resonance effects also helps in interpreting a number of closely related phenomena: for example, the rapid variation of the cross-section of inelastic scattering of electrons observed in the vicinity of resonance conditions (Horio and Ichimiya, 1983, Marten and Meyer-Ehmsen, 1988, Spence and Kim, 1988, Horio, 1998).
Diffuse And Inelastic Scattering – Multiple Scattering Effects
Authors: Peng L -M , Dudarev S L , Whelan M J 
Published: November 2023

Abstract
In the previous chapter we showed that fluctuations of the crystal potential associated with thermal vibrations of atomic nuclei, randomly distributed lattice defects, and electronic excitations give rise to diffuse scattering of high-energy electrons. Using perturbation theory we derived an explicit expression for the amplitude of scattering of electrons by the fluctuation part of the potential. This expression takes into account the fact that the cross-section of diffuse scattering is affected by the presence of the average periodic potential of the crystal. Generalizing the approach developed in the previous chapter, we can now give a classification of processes of scattering that occur when a high-energy electron propagates through a thin crystalline specimen. Diffraction is the most important of these processes in the sense that it is observed even in the case where incident electrons are scattered by a very thin crystal. Diffraction is a coherent process and in order to evaluate the relevant amplitude of scattering it is sufficient to solve the SchrÖodinger equation describing the interaction of the high-energy electron with atoms forming the crystal lattice.
Digital Electron Micrograph Recording And Basic Processing
Authors: Peng L -M , Dudarev S L , Whelan M J 
Published: November 2023

Abstract
In this chapter we will discuss the recording and basic processing of digitized electron micrographs, including electron microscope images or diffraction patterns. The major advantage associated with using digitized images is that they may be readily processed with computers and compared with theoretical calculations. The commonly used electron recording media include photographic film, TV cameras, charge-coupled device (CCD) cameras (Mooney et al., 1990), and image plates (IP) (Ogura et al., 1994). Ideally an electron recording device should be able to record electron images without degrading their resolution and adding appreciable noise, and to have a large number of pixels, wide dynamic range, and excellent linearity. An ideal electron recording device should also be of the on-line type, i.e. it should be able to display images simultaneously or within seconds of the moment when they are recorded. Photographic film and IP are off-line recording media and are not suitable for the majority of on-line applications.
Image Formation And The Retrieval Of The Electron Wave Function
Authors: Peng L -M , Dudarev S L , Whelan M J 
Published: November 2023

Abstract
In this chapter we discuss the process of image formation in a transmission electron microscope. For electron microscopes fitted with either a tungsten or LaB6filament the illumination may be regarded as perfectly incoherent, while for fieldemission gun (FEG) electron microscopes the illumination is partially coherent.
Chemistry in the Winds of Young Stellar Objects
Authors: Glassgold A E 
Published: November 2023

Abstract
The realization that powerful winds accompany the formation of stars has played an important role in understanding how stars form (e.g. Shu, Adams and Lizano 1987; Lada and Shu 1990). Although considerable evidence for mass loss from young stellar objects (YSOs) existed before 1980, the discovery of bipolar molecular outflows (Snell, Loren and Plambeck 1980; the review by Lada 1985; Snell 1987; Fukui et al. 1993; Bachiller 1996) was a turning point in star formation research. Some of the striking phenomena related to the bipolar outflows are forbidden lines with asymmetric lineshapes, Herbig-Haro objects (cf. Chapter 10), and jets (reviewed by Edwards, Ray and Mundt 1993). When we also consider that low-mass stars (our primary concern here), form in dense cloud cores (cf. Chapter 5) and that much of the matter is transferred to one through an accretion disc, we can appreciate that the formation of a star involves a number of interacting systems with different size scales and physical properties.
Photon-dominated Regions
Authors: Sternberg Amiel 
Published: November 2023

Abstract
Photon-dominated regions (PDR.s) are produced in dense neutral hydrogen clouds exposed to far-ultraviolet (FUV) radiation fields (6–13.6 eV). PDR.s are present at the edges of HII regions, in reflection and planetary nebulae, and are pervasive inside clumpy star-forming molecular clouds illuminated by direct and scattered stellar FUV radiation. PDR.s are present in starburst galaxy nuclei and active galactic nuclei.
Introduction to Stellar Evolution
Authors: Schonberner Detlef , Blocker Thomas 
Published: November 2023

Abstract
Stars are an important constituent of galaxies and are exclusively responsible for the production, reprocessing and dissemination of the heavier elements. The existence of these elements provides the necessary prerequisite to establish chemical reactions under suitable conditions which then ultimately lead to the formation of organic molecules. Hence, it is of considerable importance to acquire a comprehensive and precise knowledge of all the complex physical processes that occur deep inside the stars, in their envelopes and also in the flow of matter from their surfaces into the interstellar medium.
Dust Formation in Novae
Authors: Rawlings Jonathan 
Published: November 2023

Abstract
Dust is a ubiquitous and vital component of the interstellar medium. Its formation in the hot winds ejected during the outburst of novae is a well-established phenomenon. However, the mechanisms by which dust is formed and the criteria which determine the efficiency of that process are very poorly understood. Central to these problems is the fact that the chemistry of dust grain nucleation and growth exists on the periphery of our understanding of interstellar chemical processes (cf. Chapters 12, 13). It bridges the microscopic world of molecules and chemical kinetics and the macroscopic world of bulk grain solid-state chemistry and thermodynaµiics. The intermediate regime is complex and largely unknown. To illustrate this point we should bear in mind that even, a relatively simple organic intermediate based on a few tens of carbon atoms may have many millions-of isomers. It is quite clear that for the most general case we- have neither adequate data, nor the requisite computational power to be able to model ,the chemical kinetics of these chemical intermediates. In this chapter we investigate the mechanisms that lead to dust formation in the ejecta of novae, and how the apparently hostile environment of a nova still manages to be conducive to molecular processes. The harshness of the environment has both beneficial and complicating effects on the chemical modelling. Although novae may seem to be a somewhat specialized test bed for dust grain nucleation theory, the general conclusions that can be drawn have relevance to all studies of astrophysical dust formation.
Beyond silicon:the rise of compound semiconductors
Authors: O’Donnell Kevin P 
Published: November 2023

Abstract
This is a book about gallium nitride and its alloys. To those physicists, chemists, materials scientists, and technologists who are fortunate enough to be working with these materials at the present time, there can be no doubt that the nitrides are the most fascinating of all semiconductors. At the same time, the nitrides are the materials most likely to be exploited commercially in the years leading up to the millennium. Perhaps our degree of fascination is closely related to the marketability? After all, researchers are as aware as anyone of the commercial realities embedded in scientific activity. The purpose of this introductory chapter is to provide an answer to some basic questions concerning the place of nitrides among the families of semiconductors that lie beyond silicon.We should begin by noting that silicon is the prime semiconductor, accounting for an estimated 99% of commercial production, in terms of raw material (this is only an estimate: you could probably beat me down to 95% on a bad day) and some 90% of research and development costs. Silicon is an elemental semiconductor, from Group IV of the periodic table.
Convergence of the Energy for the Thomas-Fermi-Von Weizs ä.Cker Model With Yukawa Potential
Authors: Catto Isabelle , Bris Claude Le , Lions Pierre-Louis 
Published: November 2023

Abstract
This chapter is devoted to the proof of the existence of a limit for the energy per unit volume in the setting of the TFW model with Yukawa potential, and in the setting of some related models. Let us first recall in this introduction the setting of the TFW problem with Yukawa potential, that we have introduced above in Section 1.5 of Chapter 1. We denote by
Convergence of the density for the Thomas-fermi-von weizsäcker model with yukawa potential
Authors: Catto Isabelle , Bris Claude Le , Lions Pierre-Louis 
Published: November 2023

Abstract
Whereas in Chapters 2 and 3 we were interested in the behaviour of the energy per unit volume when the molecular system asymptotically approached an infinite crystal, we begin with this chapter our investigation on the behaviour of the electronic density. Let us recall that the main questions on this density, that we introduced in Chapter 1, are: Does the electronic density go to a limit, and does this limit share the same periodicity as the infinite lattice of the crystal?
Vortices in Superconductors
Authors: Pismen L M 
Published: November 2023

Abstract
A superconductor is a charged superfluid where dissipationless superflow manifests itself as supercurrent. The order parameter in the macroscopic theory of superconductivity is a complex scalar that expresses, as in the Ginzburg·Landau theory of superfluids, the wave function of the Bose condensate, formed in this case by Cooper pairs ·- electron pairs combining into quasiparticles with zero spin (Landau and Lifshitz IX, 1987; Tinkham, 1994). Since the Bose condensate is charged, the energy functional should include an interaction with the electromagnetic field.
Ecological speciation in postglacial fishes
Authors: Schluter Dolph 
Published: November 2023

Abstract
The ecological processes that drive speciation are poorly understood. The topic has received only sporadic attention over the past few decades, confined largely to a fraction of literature devoted to the possibility of speciation in sympatry (Rice and Hostert 1993; Bush 1994). Progress in identifying environmental mechanisms has been slow regardless of the putative geographic mode of speciation. By ‘speciation’ I mean the evolution of reproductive isolation. ‘Ecological processes’ are the interactions between individual organisms and their environment that cause natural selection and that drive population establishment, growth, and decline.
How ‘molecular leakage ‘ can mislead us about island speciation
Authors: Clorkc Bryan , Johnson, M S , Murray James 
Published: November 2023

Abstract
It is often supposed that to reconstruct the true phylogeny of organisms we should use characters or sequences that are, as nearly as possible, selectively neutral. Those under selection are thought to be unsatisfactory because different lineages can converge when they are exposed to similar environments. Here we report evidence that, in groups of sympatric species, neutral sequences may be seriously misleading about evolutionary relationships, while genes under selection may yet contain valid phylogenetic information.
Quantum mechanics of the atom-radiation interaction
Authors: Loudon Rodney 
Published: November 2023

Abstract
The calculations of the preceding chapter display some of the inadequacies of the Einstein theory of interaction of light with atoms. The theory itself gives no prescription for computing the values of the A and B coefficients appropriate to a given atomic transition. For this one must look to the quantum-mechanical theory of transition probabilities. As light beams are generated by emission from atoms and measurements on light beams ultimately depend on the absorption of light by atoms, it is essential to cover the theory of the atomic interaction processes, even though the main interest of the book is the quantum nature of the light itself. More seriously, the Einstein theory is applicable only for broad-band illumination of the atom, where the energy in the incident light is distributed smoothly across the frequencies within the linewidth of the atomic transition. By contrast, many experiments with laser sources use light beams whose frequency distributions are much narrower than atomic transition linewidths.
Classical theory of optical fluctuations and coherence
Authors: Loudon Rodney 
Published: November 2023

Abstract
The study of the classical theory of optical fluctuations and coherence is an important preliminary to the development of the corresponding quantum-mechanical theory. The classical theory is useful for a physical understanding of the various effects and many of the classical concepts carry over into the quantum theory. In addition, a knowledge of the classical theory is useful for identification of the nature of the specifically quantum properties that some light beams may exhibit. Thus it is shown in Chapter 5 that the classical and quantum theories yield the ame predictions for chaotic light, but that there exist other kinds of light that elude any satisfactory classical description. The nature of such ‘nonclassical’ light i5, of course, more sharply appreciated by contrast with the limitations on the possible kinds of light inherent in the classical theory.
Quantization of the radiation field
Authors: Loudon Rodney 
Published: November 2023

Abstract
The present chapter is devoted to a description of the procedure by which quantum mechanics is applied to the electromagnetic field. We obtain expressions for the operators that represent the field observables and we examine some of their properties. The quantization introduces characteristic quantum-mechanical effects into the properties of the radiation field, for example field operators that do not commute with each other and thus represent incompatible measured quantities. The Hamiltonian of the coupled radiation-atomic system is expressed wholly in terms of quantum-mechanical operators. We show that the full quantum theory of the interaction between the radiation field and atoms produces the same transition rates for absorption and stimulated emission as does the semiclassical theory. The rate of spontaneous emission confirms that obtained from the phenomenological Einstein theory. The treatment of absorption of radiation by atoms also identifies the quantum-mechanical operator that represents a measurement of the energy or intensity of a light beam, and this has important consequences for the descriptions of the experiments that can be performed in practice.
Marine Resource Use
Authors: Monk Kathryn A , Fretes Yance de , Reksodiharjo-Lilley Gayatri 
Published: November 2023

Abstract
Indonesia is extremely rich in marine resources. The diverse marine ecosystems in NT&M and the physical environment which supports a variety of different habitats make this region highly diverse in marine resources. The upwelling phenomenon in the Banda Sea and Arafura Sea during the east monsoon in May to August further add to the increase of these resources.
Drawing graphs in the plane
Authors: Matoušek Jiří , Nešetřil Jaroslav 
Published: November 2023

Abstract
Often it is advantageous to draw graphs. As you can see, most of the graphs in this book are specified by a picture (instead of a list of vertices and edges, say). But so far we have been studying properties of graphs not related to their drawings, and the role of drawings was purely auxiliary. In this chapter the subject of analysis will be the drawing of graphs itself and we will mainly investigate graphs that can be drawn in the plane without edge crossings. Such graphs are called planar. From the numerous pictures shown so far and from the informal definition given in Section 3.1, the reader might have gained a quite good intuition about what is meant by a drawing of a graph. Such an intuition is usually sufficient if we want to show, say, that some graph is planar-we can simply draw a suitable picture of the graph with no edge crossings. However, if we want to prove, in a strictly logical way, that some graph is not planar, then we cannot do without a mathematical definition of the notion of a drawing, based on other exact mathematical notions. Today’s mathematics is completely built from a few primitive notions and axioms of set theory-or at least the majority of mathematicians try to ensure it is.
The Jordan normal form
Authors: Kaye Richard , Wilson Robert 
Published: November 2023

Abstract
If a linear transformation f : V → V is not diagonalizable, we may still ask for a basis with respect to which the matrix of f is as ‘nice as possible’. It turns out that we can always obtain such a basis where this matrix is in Jordan normal form; that is, a special upper triangular form where the only nonzero entries off the diagonal are entries equal to 1 just above repeated eigenvalues. Such forms will enable us to solve a much greater variety of simultaneous difference and differential equations.
Genetic diversity in natural populations
Authors: Harwood John , Amos William 
Published: November 2023

Abstract
The Convention on Biological Diversity requires signatories to protect diversity at all levels from the genome to the ecosystem. This acknowledgement of the importance of genetic diversity within species is only right and proper, since this diversity is the base material on which all variety ultimately depends. Genetic diversity (whether measured by levels of heterozygosity or number of alleles per locus) is usually correlated with fitness (Mitton and Grant 1984; Allen doff and Leary 1986), and populations which are genetically diverse should be moreable to respond to parasites, predators, and environmental change than their genetically impoverished counterparts. However, levels of genetic variability differ markedly between major taxonomic groups (Ward et al.1992), and even between closely related species within the same taxon. Some species which are predicted to be genetically impoverished are not, while others harbour much less variability than expected. Similarly, there are exceptions to the rule that high levels of genetic variability equate to evolutionary health: some populations with low genetic diversity are increasing exponentially and others are declining, although they possess great variability.
Explosive speciation of African cichlid fishes
Authors: Turner George F 
Published: November 2023

Abstract
Lakes can be considered as inverted islands, as far as freshwater organisms are concerned, and the great lakes of East Africa, clustered in and around the African Rift valley, can be considered an archipelago where a single family of fishes, the Cichlidae, has radiated to produce more than 1500 species. Even though they were only known from a small and unrepresentative collection of preserved material, the unusual diversity of these fishes came to the attention of major figures in the modern synthesis of evolutionary biology in the first half of the twentieth century (Huxley 1942; Mayr 1942). The cichlid fishes rapidly became established as a textbook example of ‘adaptive radiation ‘ or ‘explosive speciation ‘. Recent studies are only now revealing that the number of species has been greatly underestimated, while the radiations in individual lakes may be much younger than has been suspected. The mechanisms underlying this extraordinary radiation are still unclear, but a combination of field studies, laboratory breeding experiments and application of molecular techniques has already overturned a number of theories.