bluuebunny/crossref_metadata_2025_split huggingface dataset:
A new look at the relationship between diversity and stability
Authors: Loreau M , Downing A , Emmerson M , Gonzalez A , Hughes J , lnchausti P , Joshi J , Norberg J , Sala O 
Published: November 2023

Abstract
The relationship between biodiversity and ecosystem functioning has emerged as one of the most exciting and controversial research areas in ecology over the last decade. Faced with the prospect of a massive, irreversible loss of biodiversity, ecologists have begun investigating the potential consequences of these dramatic changes in biodiversity for the functioning of natural and managed ecosystems. These investigations have been motivated by both the scientific challenge and the need to understand better the role biodiversity plays in providing sustainable ecological goods and services for human societies.
Introduction
Authors: Castel B , Towner I S 
Published: November 2023

Abstract
In 1956 Roger Blin-Stoyle wrote a very useful monograph [1] entitled Theories of Nuclear Moments. Since then the body of experimental data available on ground and excited states of nuclei has increased enormously. Not only are the spins, parities, and electromagnetic moments of ground states of most nuclei known, but today moments are routinely measured in short-lived isomers through advancements in such techniques as laser spectroscopy. Likewise, since 1956, there have been many theoretical advancements in the-understanding of the properties of nuclei. Yet the aim of this text remains the same as that of Blin-Stoyle’s: to discuss electromagnetic moments and their interpretation in terms of current nuclear theories.
Collective Models
Authors: Castel B , Towner I S 
Published: November 2023

Abstract
While the static moments of nuclei located close to the major shell closures are well described by the independent particle model (with core polarization and meson-exchange current corrections) nuclei further away from shell closures are characterized by non-spherical shapes and large quadrupole moments. To give a quantitative discussion of such nuclei will require a more phenomenological approach. It will be necessary to introduce some collective variables to describe cooperative modes of motion and a few intrinsic variables to describe the few extra-core nucleons not participating in the collective motion. Any coupling between the collective and intrinsic variables is taken as weak and studied through perturbation theory. Collective variables are only useful if the energy Hamiltonian can be separated into terms that depend on the collective variables and terms that do not. Then the eigenstates are of product form.
Single-Particle and Shell-Model Theories of Quadrupole Moments
Authors: Castel B , Towner I S 
Published: November 2023

Abstract
We now turn our attention to electric quadrupole moments. These moments have traditionally been invoked as good indicators of collective effects in contrast to magnetic moments. The reason for that is simple and has to do with the difference in the nature of the two relevant operators. The magnetic dipole operator leads to opposite contributions from a state |ψ⟩ and its time-reversed conjugate |ψ˜⟩ (since both currents and spin change sign in the |ψ⟩→|ψ˜⟩ conjugation). Thus one member of the paired-off nucleon cancels the contribution from the other. Such is not the case for the quadrupole operator since its contributions are invariant under time reversal. Thus if nuclear correlations can be induced by some deformation, a coherent buildup of quadrupole moment can be expected. As we shall see, this coherence can lead to sizeable effects which will be examined in this chapter in the light of single-particle and various shell models. The next chapter will be devoted to a survey of the macroscopic models currently available for the study of quadrupole moments and nuclear deformations.
Giant Resonances
Authors: Harakeh M N , van der Woude A 
Published: November 2023

Abstract
Giant resonances are collective excitations of the atomic nucleus, a typical quantum many-body system. The study of these fundamental modes has in many respects contributed to our understanding of the bulk behaviour of the nucleus and of the dynamics of non-equilibrium excitations. Although the phenomenon of giant resonances has been known for more than 50 years, a large amount of information has been obtained in the last 10 years. This book gives an up-to-date, comprehensive account of our present knowledge of giant resonances. It presents the experimental facts and the techniques used to obtain that information, describes how these facts fit into theoretical concepts and how this allows to determine various nuclear properties which are otherwise difficult to obtain. Included as an introduction is an overview of the main facts, a short history of how the field has developed in the course of time, and a discussion of future perspectives.
Magneto-optical and electro-optical phenomena
Authors: Balkanski M , Wallis R F 
Published: November 2023

Abstract
This chapter is divided into three major parts. In the first part magneto optical phenomena are discussed from a classical point of view. Optical absorption as exemplified by cyclotron resonance and dispersion as exemplified by the Faraday and Voigt effects are analyzed. In the second part a quantum mechanical treatment is presented. The theory of the Landau levels of an electron moving in a uniform magnetic field is developed and applied to optical properties. In the third part the effects of an external electric field on optical properties are discussed.
Gauge Groups
Authors: Stancu Fl 
Published: November 2023

Abstract
The continuous symmetries we have discussed until now are calledglobal symmetries. The parameters a ρ, Equation (5.51), of a Lie group are space-time independent. In a field theory, this implies that fields at different space-time points transform by the same amount There are theories where the symmetry transformation contains space-time-dependent parameters aρ (x). These transformations are called local or gauge (Weyl 1929) and form gauge groups. They generate the gauge interactions; electromagnetic, weak, and strong interactions are all gauge interactions. Therefore, the present theory of elementary particle physics is based on the principle of gauge symmetries.
Potential flow
Authors: Guyon Etienne , Hulin Jean-Pierre , Petit Luc , Mitescu Catalin D 
Published: November 2023

Abstract
The study of an ideal (perfect) fluid-’dry water’, as Richard P Feynman refers to it in the Feynman Lectures in Physics-is a crucial part of fluid dynamics. In the mechanics of solids, the laws of motion can be expressed, in the absence of friction, in terms of conservation laws. In a similar way, the absence of viscosity in fluid mechanics allowed us, in Chapter 5, to express in a simpler way the energy and momentum conservation laws, and to solve a number of problems without needing a detailed knowledge of the local motion.
Flow at low Reynolds numbers
Authors: Guyon Etienne , Hulin Jean-Pierre , Petit Luc , Mitescu Catalin D 
Published: November 2023

Abstract
Flows at low Reynolds number, a concept introduced in Chapter 2, are characterized by the fact that viscosity effects dominate inertial ones. The Stokes equation, which describes these flows, is linear, because the convective non-linear term (∇. ∇) ∇ can be neglected. For the case of parallel flows discussed in Chapter 4, this convective term was rigorously zero.
Electromagnetic radiation is produced by electrons
Authors: Duke Philip John 
Published: November 2023

Abstract
In the previous chapter we introduced the idea of the electromagnetic wave as the regular variation of electric and magnetic fields. We explained how these waves transport energy in the form of photons from one place to another. We also described how the photon energy is related to the wavelength and frequency of the wave. Our aim in this chapter is to begin with the experimental observation that electrons are the source of both electric and magnetic fields and to show how this observation leads to a complete description, in mathematical terms, of the fields themselves and their propagation through space and time. The mathematical description which we are aiming for is known as Maxwell’s equations for the electromagnetic field. The argument will be followed at a very elementary level and can be omitted by those who are already familiar with the subject. On the other hand, those who wish for a more detailed and rigorous treatment will need to supplement this chapter with one of the many textbooks on the theory of electromagnetism and electrodynamics.
Photon spectral distribution integrated over vertical angles
Authors: Duke Philip John 
Published: November 2023

Abstract
The fact that the radiation from the accelerated electron is emitted into a narrow forward cone means that quite often an observer is interested in the photon energy (or the total number of photons) emitted over all vertical angles. This is the case when the target being irradiated subtends a vertical angle which is significantly larger than the opening angle of the forward cone from the emission point. The energy radiated by the passage of one electron into unit solid angle, located at an angle θ above the plane of the electron orbit, and unit frequency interval is given as usual by eqn (7.1) which is identical to (5.44):
Behaviour of the electron beam in a synchrotron radiation storage ring. The concept of phase space
Authors: Duke Philip John 
Published: November 2023

Abstract
In this chapter, we develop a formal description of the electron beam in a storage ring. We begin by defining the magnetic field function of an elementary storage ring which includes only the dipole and quadrupole fields. This will be sufficient for a basic understanding of the subject. Next, we develop an equation which describes the motion of the electron in this field and in Chapter 11 we shall show how the solutions of this equation of motion describe the oscillatory behaviour of the electron beam in the horizontal and vertical planes.
Basic Features Of Superconductivity
Authors: Asner Fred M 
Published: November 2023

Abstract
The unexpected discovery of superconductivity by H.K. Onnes in 1911 in Leyden was due to research and development activities in two domains: the liquefaction of gases, leading in 1908 to the liquefaction of helium, and to the investigation of the electric conductivity of metals, which Onnes intended to explore at temperatures approaching absolute zero [1, 2].
Polymer gels
Authors: Doi M , See H 
Published: November 2023

Abstract
A polymer gel is a three-dimensional network of polymer chains joined together at a number of connection sites, as shown in Fig. 3.1. The connections may be due to covalent chemical bonds or physical interactions such as hydrogen bonds or electrostatic forces. The former are called chemical gels, the latter physical gels. There are basically two ways to make a chemical gel. One way is to add a cross linking agent to a system of polymer chains, causing them to form a network.
Mathematical Theory of Quantum Fields
Authors: Araki Huzihiro 
Published: November 2023

Abstract
This is an introduction to the mathematical foundations of quantum field theory, using operator algebraic methods and emphasizing the link between the mathematical formulations and related physical concepts. It starts with a general probabilistic description of physics, which encompasses both classical and quantum physics. The basic key physical notions are clarified at this point. It then introduces operator algebraic methods for quantum theory, and goes on to discuss the theory of special relativity, scattering theory, and sector theory in this context.
Scattering Theory
Authors: Araki Huzihiro 
Published: November 2023

Abstract
In this chapter we explain how particle scattering can be described by local observables. First we introduce the concept of the S-matrix, which is an idea common to classical and quantum mechanics. We show the construction of incoming and outgoing states which have a certain asymptotic behaviour at time −∞ and +∞, and we also show that the constructed states have an acceptable physical asymptotic behaviour. Then we derive the representation of the S-matrix given by these scattering states and discuss its properties.
Magnetostatic Phenomena
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
The most direct manifestation of magnetism is the force of attraction or repulsion between two magnets. This phenomenon can be described by assuming that there are ‘free’ magnetic poles on the ends on each magnet which exert forces to one another. These are called ‘Coulomb forces’ by analogy with the Coulomb forces between electrostatically charged bodies. Consider two magnetic poles with strengths ofm1(Wb (weber)) andm2(Wb) respectively, separated by a distancer(m).
Antiferromagnetism And Ferri Magnetism
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
In antiferromagnetism, neighboring spins are aligned antiparallel to one another so that their magnetic moments cancel. Therefore an antiferromagnet produces no spontaneous magnetization and shows only a feeble magnetism. The relative magnetic susceptibility of antiferromagnetic materials, ranges from 10-5 to 1O-2, the same as for paramagnets. The only difference is the presence of an ordered spin structure, as shown in Fig. 7.1. When an external magnetic field is applied parallel to the spin axis, the spins which are parallel and antiparallel to the field experience almost notorque and so keep their ordered spin arrangement. Therefore the susceptibility in this case is smaller than for a normal paramagnet.
Magnetocrystalline Anisotropy
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
The termmagnetic anisotropyis used to describe the dependence of the internal energy on the direction of spontaneous magnetization. We call an energy term of this kind amagnetic anisotropy energy.Generally the magnetic anisotropy energy term has the same symmetry as the crystal structure of the material, and we call it amagnetocrystalline anisotropy.
Magnetostriction
Authors: Chikazumi Sōshin , Graham, Jr C D 
Published: November 2023

Abstract
Magnetostriction is the phenomenon whereby the shape of a ferromagnetic specimen changes during the process of magnetization. The deformationδl/ldue to magnetostriction is usually very small, in the range 10−5 to 10−6 A deformation of this magnitude can be conveniently measured by means of a strain-gauge technique, the details of which are described later. Although the deformation is small, magnetostriction is an important factor in controlling domain structure and the process of technical magnetization is an important factor in controlling domain structure and the process of technical magnetization.
Atomic Masses
Authors: Wapstra A H 
Published: November 2023

Abstract
Since the discovery that elements occur in various isotopes, the masses M of their atoms are known to be nearly integers A (the mass number) if expressed in suitable units. Since 1960, the unit u (or mu) used is l/12th of the mass of a 12C atom in its nuclear and atomic ground states. Mass values as given in tables (e.g. ref. 1) are those of atoms in such ground states (but for some exceptions where the nucleus is in an isomeric state). The reason for giving atomic masses rather than nuclear ones is that until very recently, measurements yielded more directly, and accurately, data on atomic masses than on nuclear ones, as will become clear from the discussions below.
Static scattering properties of colloidal suspensions
Authors: Klein Rudolf , D’Aguanno Bruno 
Published: November 2023

Abstract
The microstructure of colloidal suspensions is commonly studied by scattering experiments. A considerable amount of theoretical background is needed to extract information about the microstructure from the measured scattered intensity I(k) and to understand such microstructure in terms of properties of the suspended particles and the solvent. It is the purpose of this chapter to provide this background and to present and discuss results for realistic systems. The discussion will almost entirely be restricted to suspensions of spherical particles. For such systems the microstructure is mainly described by the pair distribution function g(r), which is closely related to the probability of finding a particle at the distance r from another particle.
Effective Quark Interactions
Authors: Ripka Georges 
Published: November 2023

Abstract
Quark models are usually expressed in terms of effective interactions, which reflect the symmetries of strong interactions. However, symmetry is not sufficient to determine them. The forms of the effective interactions are further dictated by their phenomenological fitness and by their simplicity of use. We should keep in mind that we are not discussing the effective interactions with the aim of adding them to a confining potential. Rather, we have the intention of using them in models which can account for the spontaneously broken chiral symmetry of the vacuum and, hopefully also, for the formation of hadrons. Attempts to derive effective quark interactions from QCD have followed different directions. Some attempts, sometimes referred to as the global color model, lead to an effective gluon exchange interaction, the space—time dependence of which is governed by a phenomenologically determined effective gluon propagator [17, 18, 19, 20, 21, 22] or which is based on the so-called field strength approach [23]. Other attempts, based on so-called hadronization methods, introduce auxiliary non-local fields which re-sum ladders of gluon exchange diagrams [14, 24]. Another direction, which derives a different effective interaction between quarks, stems from a study of their propagation in an instanton liquid, which describes the QCD vacuum [25, 26, 27). In this chapter we describe the various interactions which are commonly used and we do not attempt to derive them from QCD.
The Nambu Jona-Lasinio Model
Authors: Ripka Georges 
Published: November 2023

Abstract
Like other models which account dynamically for the spontaneous breakdown of chiral symmetry, it is unable to confine color and quarks. Hadrons appear in the model as bound (instead of confined) states of quarks. The model was conceived before the discovery of quarks. It was originally designed to be a dynamical model of spontaneous chiral symmetry breaking in the vacuum (39, 40]. References to reviews and applications are given in chapter 10 for the meson sector and in chapters 12 and 13 for the baryon sector.
Chiral Solitons
Authors: Ripka Georges 
Published: November 2023

Abstract
The possibility of describing baryons as chiral solitons is based on the observation that bound states can be formed when quarks interact with a chiral field. Friedberg and Lee had previously shown how bound states (called solitons) could be formed when quarks interact with scalar fields (see the reviews in [183, 184]). Chiral solitons were discovered when the scalar field was supplemented by a pion field, so as to implement chiral symmetry. This lead naturally to the calculation of soIitons using the Gell-Mann Levy model (section 11.3), also extended to include vector fields [169, 170, 171]. These, as well as solitons calculated with color dielectric models, are reviewed in [172). Quite similar solitons are obtained using the Nambu Jona-Lasinio model. They are reviewed in [185, 186].
Permanent-magnet motors
Authors: Hanitsch R 
Published: November 2023

Abstract
New electromechanical drive systems endowed with a combination of desirable characteristics are a considerable impetus to technological progress. Taking a robot axis drive as an example, it should combine a low moment of inertia and low torque pulsations with high power/weight ratio, high torque overload capability and high efficiency. The advent of rare-earth permanent magnets has opened up the prospect of significantly improved designs for such devices, as well as for a range of other industrial drives, small electrical machines and micromotors.
The Principles of Equilibrium Thermal Monte Carlo Simulation
Authors: Newman M E J , Barkema G T 
Published: November 2023

Abstract
In Section 1.3.1 we looked briefly at the general ideas behind equilibrium thermal Monte Carlo simulations. In this chapter we discuss these ideas in more detail in preparation for the discussion in the following chapters of a variety of specific algorithms for use with specific problems. The three crucial ideas that we introduce in this chapter are “importance sampling”, “detailed balance” and “acceptance ratios”. If you know what these phrases mean, you can understand most of the thermal Monte Carlo simulations that have been performed in the last thirty years.
The using n1odel and the Metropolis algorithm
Authors: Newman M E J , Barkema G T 
Published: November 2023

Abstract
In Section 1.2.2 we introduced the using model, which is one of the simplest and best studied of statistical mechanical models. In this chapter and the next we look in detail at the Monte Carlo methods that have been used to investigate the properties of this model. As well as demonstrating the application of the basic principles described in the last chapter, the study of the using model provides an excellent introduction to the most important Monte Carlo algorithms in use today. Along the way we will also look at some of the tricks used for implementing Monte Carlo algorithms in computer programs and at some of the standard techniques used to analyse the data those programs generate.
Other Algorithms for the Using Model
Authors: Newman M E J , Barkema G T 
Published: November 2023

Abstract
In the last chapter we saw that the Metropolis algorithm with single-spin-flip dynamics is an excellent Monte Carlo algorithm for simulating the using model when we are interested in temperatures well away from the critical temperature Tc However, as we approach the critical temperature, the combination of large critical fluctuations and long correlation time makes the errors on measured quantities grow enormously. As we pointed out, there is little to be done about the critical fluctuations, since these are an intrinsic property of the model near its phase transition (and are, what’s more, precisely the kind of interesting physical effect that we want to study with our simulations). On the other hand, the increase in the correlation time close to the phase transition is a function of the particular algorithm we are using-the Metropolis algorithm in this case-and it turns out that by using different algorithms we can greatly reduce this undesirable effect. In the first part of this chapter we will study one of the most widely used and successful such algorithms, the Wolff algorithm. Before introducing the algorithm however, we need to define a few terms.