bluuebunny/crossref_metadata_2025_split huggingface dataset:
Models
Authors: Binney J J , Dowrick N J , Fisher A J , Newman M E J 
Published: November 2023

Abstract
In this chapter we introduce a number of models that have played important rô les in the development of the theory of phase transitions. To avoid disappointment later it should be emphasized here that these are all toy models designed to be tractable rather than realistic. In fact some are frankly unphysical and are of interest mainly for the light they throw on other, more realistic models. But among the systems we shall play with are ones that seem to capture the essence of what happens when a real system undergoes a continuous phase transition.
Numerical simulations
Authors: Binney J J , Dowrick N J , Fisher A J , Newman M E J 
Published: November 2023

Abstract
We have now seen how powerful the tools of statistical mechanics can be in the study of complex systems in thermal equilibrium and how they can be used to determine exactly the behaviour of some simplified, but nevertheless interesting, models of phase transitions. However, these exact solutions are sometimes lengthy and difficult and there is no guarantee that any particular model will yield exact results. For example, we were able to solve the two-dimensional, but not the three-dimensional, Ising model, and that only in zero magnetic field. So, it is natural to consider whether we can use a computer to simulate these systems. In this chapter we shall see that this is indeed possible; a great deal of our understanding of critical phenomena is based wholly or partly on the results of such numerical work. However, as we shall also see, such simulations are not entirely straightforward and a number of tricks are needed to obtain accurate results. This is partly a consequence of the very physics that makes the phase transitions interesting to start with. One should probably think of numerical simulation as a whole subject, almost an art, of its own; we shall have time only to scratch at the surface and discuss a few of the most important ideas.
Diagrammatic perturbation theory
Authors: Binney J J , Dowrick N J , Fisher A J , Newman M E J 
Published: November 2023

Abstract
In the last chapter we introduced the Landau-Ginzburg model and calculated its partition function in a crude approximation known as Landau theory. In this chapter we develop a systematic method for calculating the Landau-Ginzburg partition function, the associated correlation functions, and the Helmholtz and Gibbs free energies. In subsequent chapters we shall use the techniques developed here to find the critical exponents for the Landau-Ginzburg model.
The calculation of critical exponents for T ≤ T
c
Authors: Binney J J , Dowrick N J , Fisher A J , Newman M E J 
Published: November 2023

Abstract
Before we dive into the calculation of the first of our critical exponents, it will be helpful for us to consider a little more closely some of the problems that arise from the perturbation expansion we have developed for our correlation functions. This expansion is an expansion in powers of the coupling constant A, whose coefficients are integrals given by the Feynman rules. In §9.4, we were concerned with the behaviour of some of these integrals as we let the wavevector cutoff A tend to infinity.
Production of temperatures to 1 K
Authors: White Guy K , Meeson Philip J 
Published: November 2023

Abstract
In Chapter 2 we look more closely at the methods of cooling down to ˜1 K which are currently in general use, concentrating on the techniques and problems encountered on the laboratory scale rather than in industrial installations which deal with hundreds of tonnes of LNG (liquefied natural gas), liquid oxygen or liquid hydrogen. Further details of many of these methods may be found in Collins and Cannaday (1958), Croft (1971) and Walker and Bingham (1994). We described in Chapter 1 how cooling takes place through a process of isothermal compression and adiabatic decompression, literally when the working substance is a gas such as nitrogen or helium and more conceptually in the case of, for instance, magnetic cooling. In order for the refrigerator to operate continuously the cooling needs to become cyclic, that is, the compression-decompression cooling process needs to be repeated indefinitely. We describe below the various schemes that have emerged for achieving this.
Hard disks and spheres
Authors: Krauth Werner 
Published: November 2023

Abstract
In the first chapter of this book, we considered simple problems in statistics: pebbles on the beach, needles falling but never rolling, and people strolling on heliports by night. We now move on to study model systems in physics-particles with positions, velocities, and interactions-that obey classical equations of motion. To understand how physical systems can be treated with the tools of statistics and simulated with Monte Carlo methods, we shall consider the hard-sphere model, which lies at the heart of statistical mechanics. Hard spheres, which are idealizations of billiard balls, in free space or in a box, behave as free particles when ever they are not in contact with other particles or with walls, and obey simple reflection rules on contact.
Density matrices and path integrals
Authors: Krauth Werner 
Published: November 2023

Abstract
In this chapter, we continue our parallel exploration of statistical and computational physics, but now move to the field of quantum mechanics, where the density matrix generalizes the classical Boltzmann distribution. The density matrix constructs the quantum statistical probabilities from their two origins: the quantum mechanical wave functions and the Boltzmann probabilities of the energy levels. The density matrix can thus be defined in terms of the complete solution of the quantum problem (wave functions, energies), but all this information is available only in simple examples, such as the free particle or the harmonic oscillator. A simple general expression exists for the density matrix only at high temperature.
Gene duplication and evolution
Authors: Lynch Michael 
Published: November 2023

Abstract
Motivated in part by Ohno’s (1970) influential book, substantial attention has been given to the idea that gene duplication is a major mechanism for the origin of new gene functions. A theoretical population genetic framework for understanding the evolutionary mechanisms responsible for the success versus demise of gene duplicates has begun to emerge. Substantial evidence now exists that many of the key evolutionary lineages of multicellular eukaryotes have experienced one or more complete genome doublings (polyploidization) sometime in the distant past (Wolfe 2001), and the newly unveiled genomic sequences of diverse species clearly indicate that gene duplication is an ongoing process in all organisms.
Genomics and evolution: the path ahead
Authors: González-Candelas Fernando , Ho Julie C , Casa Alexandra M , Kresovich Stephen 
Published: November 2023

Abstract
The draft of the human genome sequence published by two separate groups in February 2001 (International Human Genome Sequencing Con sortium 2001; Venter et al. 2001) marks the beginning of a new era for biology and promises applications that should benefit humankind for centuries to come. Thousands of researchers from different countries have mobilized towards a common goal and now share multimillion-dollar budgets. Although initially criticized by organismal and environmental specialists for its concentration of resources and research efforts, this initiative is now widely acknowledged for its far-reaching, positive impact on all areas of biology, including evolutionary biology.
From ecosystems to molecules: cascading effects of habitat persistence on dispersal strategies and the genetic structure of populations
Authors: Denno Robert F , Peterson Merrill A 
Published: November 2023

Abstract
Knowledge of the evolutionary links between ecosystem-level properties and variation at the genetic level predates even the discovery of the molecular basis of genes. Much of the research in this arena has been motivated by observations that organisms possess attributes that enhance their performance in their local ecosystems. Early experiments provided convincing evidence such presumed adaptations to the environment often have a genetic basis, by demonstrating heritable ecotypic variation among populations (e.g. Clausen et al. 1940). More recent studies have shown that variation at the level of specific genes or gene products is clearly the result of adaptation to ecosystem properties (e.g. Koehn and Hilbish 1987).
Using molecules to understand the distribution of animal and plant diversity
Authors: Hewitt Godfrey M 
Published: November 2023

Abstract
Many questions in ecology can now be addressed through the use of molecular markers, making molecular ecology a thriving multichanneled interface. Using recently available DNA sequence information, a wide spectrum of ecological topics is being investigated. These range from paternity analysis, through population structure, to speciation and systematics; they include all living kingdoms in all realms of the globe, and have application from pest control and animal breeding to conservation and sociobiology. The field is growing rapidly, as witnessed by the number of papers and journals reporting on it.
Cambridge Undergraduate
Authors: Brown Andrew 
Published: November 2023

Abstract
The Great War changed Cambridge from a vibrant university town to a dark, cheerless place, where army divisions camped and drilled before going to fight in the trenches. Their officers spent a last few civilized weeks living in the colleges. Tens of thousands of soldiers returned to Cambridge from the front after being blinded, maimed or gassed, for treatment at the First Eastern General Hospital (a medical campground spread over the gardens and backs behind King’s and Clare Colleges). About sixteen thousand Cambridge undergraduates and recent graduates went to war, of whom a third were either killed or seriously wounded. Teaching did not stop altogether, but the undergraduate numbers for the last three years of the conflict averaged about one fifth of the pre-war level. At Emmanuel College, the photograph of the 1916 freshmen contained just five, solemn, young men – three of oriental appearance. At the end of a war that had lasted a year longer than the usual degree course, the new Master of Trinity College, Sir J.J. Thomson, was concerned that the hiatus might result in a permanent loss of traditional ways and customs. He soon realized that his worries were groundless.
Science Fantasy
Authors: Brown Andrew 
Published: November 2023

Abstract
While at the Royal Institution, Bernal began to write his memoir. He might perhaps have chosen the title, A Portrait of the Scientist as a Young Man, as a nod to his countryman James Joyce (a writer whom he admired), but instead settled on the duller but less pretentious, Microcosm. Although clearly intended for publication, Microcosm was never finished and survives only as a collection of mostly undated manuscripts (some typed) and notebooks. The writings begin with the following statement: ‘At the age of twenty-five I have set myself the task of writing down the results of my life, the sum of all the influences that have borne on me, and what my mind makes of these in its knowledge and action.’ Realizing that such an undertaking at his tender age might be regarded as impertinent, Bernal quickly acknowledged that he did not ‘despise the wisdom of age or prefer that of youth’ but thought that ‘they are different wisdoms’.
The Entertainment Of The Scientist
Authors: Brown Andrew 
Published: November 2023

Abstract
Dorothy Crowfoot spent the summer of 1934 in Cambridge taking more X-ray photographs of pepsin, but then returned to Oxford to take up a fellowship at Somerville College. At the same time, Bernal lost his other PhD researcher, Helen Megaw, who went to Vienna to spend a year working as a post-doctoral student with Hermann Mark, now professor of physical chemistry there. The loss of these two hard-working and talented young women resulted in a temporary drying-up of the stream of new data from Bernal’s laboratory. His growing involvement with the Association of Scientific Workers, FIL and the Cambridge Scientists Anti-War Group precluded him from spending the long hours necessary to generate and interpret X-ray photographs, and he could no longer summon the solitariness of purpose necessary to undertake such demanding work himself. He spent almost as much time in London as he did in Cambridge and was often out of the country. At the end of 1934, he spent two months in the USSR with Margaret Gardiner, coming home via Vienna.
Marxist Envoy
Authors: Brown Andrew 
Published: November 2023

Abstract
Soon after the war, Sage wrote that ‘the day of the wandering scholar is over’. He then spent much of the next twenty years attempting to revive the tradition. In addition to the triennial International Union of Crystallography meetings, invitations to speak at foreign universities, and his globe-trotting for the World Peace Council and the World Federation of Scientific Workers, he took several lengthy trips to nations that interested him. These visits were usually at the invitation of the national science academy of the country in question, and the ostensible reason for the visit would be a one-man review of their leading centres of science and technology. For emerging countries with limited resources, Sage represented expertise in physics, chemistry, crystallography, materials science and metallurgy, the building industry and agriculture. He was indefatigable and cheap. As a scientist, he regarded himself as a world citizen and was determined to do all he could to bring the benefits of pure and applied science to developing lands. If the places were not established communist states like China and the USSR, they were often ex-colonial nations that appeared ripe for conversion to some form of socialism, when, of course, the planning of science would become a central edict.
Do species interactions buffer environmental variation (in theory)?
Authors: Hughes J B , Ives A R , Norberg J 
Published: November 2023

Abstract
The interconnectedness of species within ecosystems underlies the popular notion that biodiversity contributes to a balance of nature. Species interactions are also fundamental to ecologists’ formulations of how biodiversity and the stability of ecosystem functioning are related. Many have reviewed how the intricacies of stability definitions affect these relationships (e.g. McCann 2000; Pimm 1984). Fewer have examined how the varied aspects of species interactions, such as strength and number, affect diversity-stability relationships in models (e.g. Benedetti-Cecchi 2000; May 1973) and experiments (e.g. Aoki and Mizushima 2001; Mulder et al. 2001).
Biodiversity and stability in soil ecosystems: patterns, processes and the effects of disturbance
Authors: Ruiter P C de , Griffiths B , Moore J C 
Published: November 2023

Abstract
Soil harbours a large part of the world’s biodiversity and governs processes that are regarded as globally important components in the cycling of materials, energy and nutrients (Wolters 1997; Griffiths et al. 2000). The taxonomy of soil organ isms is however relatively poorly known and possibly the majority of the species is still to be identified (Mikola et al., Chapter 15). Precise taxonomical descriptions of the soil biodiversity are hampered by technical difficulties in extracting and identifying the soil organisms and by the large variation in species richness among soil ecosystems (Lawton et al. 1996; Wall and Virginia 1999; Mikola et al., Chapter 15).
Slippin’ and slidin’ between the scales: the scaling components of biodiversity-ecosystem functioning relations
Authors: Bengtsson J , Engelhardt K , Giller P , Hobbie S , Lawrence D , Levine J , Vila M , Wolters V 
Published: November 2023

Abstract
Whilst the problems of scale are well-known to most ecologists, many subdisciplines of ecology are still struggling with its central concepts-how the dimensions of space and time, and levels of organization, influence ecological patterns and processes (e.g. Peterson and Parker 1998; O’Neill and King 1998; Petersen and Hastings 2001; Schneider 2001). Individual ecologists may, at their own peril, ignore the problem and focus on one scale and one level of organization only. However, the synthesis of many individual studies con ducted at different scales requires a better under standing of the influence of scale on ecological processes. This is particularly evident in the study of biodiversity and ecosystem functioning. Although studying at least two levels-community and ecosystem-most research has been performed at small spatial and short temporal scales (Loreau et al. 2001; Naeem 2001), and it is not clear if such studies can be used to inform the public and policymakers about the large-scale consequences of biodiversity loss.
Effect of biodiversity on ecosystem functioning in managed ecosystems
Authors: Vandermeer J , Lawrence D , Symstad A , Hobbie S 
Published: November 2023

Abstract
Depending on definition, as much as 90% of the terrestrial surface of the earth is estimated to be maintained in some sort of managed state, usually forestry or agriculture (Western and Pearl 1989). This very abundance should be sufficient to place managed ecosystems at the centre of the analysis of biodiversity and ecosystem function, and indeed a large literature has emerged on this topic in agricultural and forestry ecosystems (Pimentel et al. 1992; Paoletti et al. 1993; Collins and Qualset 1999). In this chapter, we first cast the major questions about biodiversity and ecosystem functioning in the context of managed systems, introducing the ideas of planned versus associated biodiversity and the intensification gradient, concepts that are unique to managed systems.
Experimental Methods Used in GR Studies
Authors: Harakeh M N , van der Woude A 
Published: November 2023

Abstract
In this chapter we present an overview of experimental techniques used to excite GRs built on the ground state. GRs can be excited through the strong (nuclear) and electromagnetic interactions. In principle, it should also be possible to excite them through the weak interaction but because of the small cross sections involved these interactions have never been used to study GRs. As is already clear from the discussion in Chapter 1, there are many different types of resonances: the major excitation modes have been illustrated in Fig. 1.3. Since the strength distributions of many of these modes overlap in excitation energy one should use a probe which is as much as possible selective for the mode one wants to study. In the inelastic scattering of charged hadrons, i.e. protons, a-particles and heavy ions, both nuclear and electromagnetic interactions contribute, but for the lighter projectiles the nuclear interaction dominates.
Properties of Isoscalar Electric GRs
Authors: Harakeh M N , van der Woude A 
Published: November 2023

Abstract
In this chapter we will present an overview of the characteristic properties of isoscalar electric (non-spin-flip) GRs. These properties are: • Excitation energy Ex; this parameter is relatively easy to determine from the experimental data, as is clear from the examples shown in Chapter 3. For a specific resonance it should smoothly depend on the size of the nucleus, i.e. on the atomic number A. • Sum-rule strength Sexp; as discussed in Chapter 2, for each type of resonance the theoretical energy-weighted sum rule (EWSR) Sth depends under certain general valid assumptions only on ground-state parameters. Usually Sexp is expressed as a fraction S of Sth. A resonance is giant if, say, S is &gt;50%. The experimental determination of Sexp from the excitation cross section can be difficult since the various resonances often overlap and are on top of a large continuum. If so, the uncertainty in S is usually ∼20%. • Width Γ: for the same reasons as for S this parameter also is sometimes difficult to determine. It is an important parameter since it reflects the damping mechanisms of the GRs.
Spin-Flip Transitions in Charge-Exchange Reactions
Authors: Harakeh M N , van der Woude A 
Published: November 2023

Abstract
In this chapter collective excitations involving particle-hole excitations induced by a residual nucleon-nucleon (NN) interaction of the type: In the liquid-drop model these modes correspond to oscillations involving the spin degree of freedom. In the isoscalar mode nucleons with spin up oscillate against nucleons with spin down; the protons and neutrons move in phase. In the isovector spin mode neutrons with spin up oscillate against protons with spin down and neutrons with spin down oscillate against protons with spin up. Microscopically, these collective excitations give information on the spin and isospin effective interactions in the nuclear medium.
Spin-Flip Strength from Inelastic Scattering
Authors: Harakeh M N , van der Woude A 
Published: November 2023

Abstract
Spin-flip transitions excited in inelastic scattering of protons, electrons and photons (magnetic resonances) have been studied both experimentally and theoretically for many decades with ever improving means. The work up to 1980 has been reviewed, for instance, by Hanna (HAN80). An extensive review of the work up to 1990 on these giant magnetic resonances can be found in reference (RAM91). Spin-flip modes can be excited by hadronic and electromagnetic probes and also, in principle, by weak probes. All these probes strongly favour excitation of the isovector spin-flip transitions over the isoscalar spin-flip ones.
Multiphonons
Authors: Harakeh M N , van der Woude A 
Published: November 2023

Abstract
In the previous chapters we discussed the properties of GRs of different multipolarities and carrying different spin-isospin quantum numbers built on the ground state of a nucleus. But according to the Brink-Axel hypothesis (BRI55,AXE62), a GR can also be built on an excited state. Its basic features such as its energy and strength, which in a mean-field approximation are determined by the nuclear force, should be unaffected by the pre-excitation of the nucleus. Thus, the energy of the resonance, with respect to the state on which it is built, and its sum-rule strength do not depend on the excitation energy and structure of that state. This feature is extensively used to study the properties of IVGDRs in hot nuclei as will be discussed in the next chapter. In this chapter we restrict ourselves to a special case, namely where the excited state itself is a GR. Although in such a double GR excitation each GR can have a different set of quantum numbers, most experimental and theoretical work refers to the case where they are identical. Only in pion charge-exchange reactions have states corresponding to the simultaneous excitation of two different GRs been observed - see Section 9.2. In principle, states which consist of more than two GRs are also possible, but such excitations have not yet been observed.
The Giant Dipole Resonance in Hot Nuclei
Authors: Harakeh M N , van der Woude A 
Published: November 2023

Abstract
A common way of getting a deeper understanding of the structure of a physical system is to submit it to extreme conditions of, for instance, temperature, pressure or stress. This applies also to nuclear systems which have been and still are studied at conditions very different from the ground state of stable nuclei. Here, we are focusing on nuclei at high excitation energies produced, for example, in nuclear fusion reactions or in inelastic scattering. These systems are unstable and decay by emission of particles (nucleons, a-particles, etc.) and heavier fragments. Various properties such as the temperature of the emitting system can be derived from measuring the spectra of the emitted particles.