bluuebunny/crossref_metadata_2025 huggingface dataset:
Storm clouds
Authors: Gregory Jane
Published: November 2023

By the end of 1962, Hoyle’s cosmology was once again to the fore. He published a textbook, Astronomy, and The Times congratulated him on this attempt to place the contemporary cosmological debate in historical context. The book concluded with an exploration of the role of radio-astronomy in deciding between big-bang and steady-state theories.1 He spent time during the winter in California, where he worked with Fowler on imploding stars, which they thought could be sources of radio waves. In the spring of 1963, around the time when the work with Fowler was being published in Nature,
‘Dear Mr Hogg ‘
Authors: Gregory Jane
Published: November 2023

In the spring of 1964, and with the prospects for an institute for theoretical astronomy still uncertain, Hoyle ‘s work at Caltech was interrupted by unwelcome news: he heard from his friend and colleague Ray Lyttleton that their Department at Cambridge, Applied Mathematics and Theoretical Physics, looked set to reappoint George Batchelor as Head. Lyttleton had received a circular letter asking him to nominate the next Head of Department, and he reported that Batchelor had ‘himself done so much to have his own name brought forward to the virtual exclusion of all others ‘ and had employed a ‘stratagem of extracting votes prematurely from inexperienced members. ‘
The beginning of the end
Authors: Gregory Jane
Published: November 2023

The future of IOTA hinged, for Hoyle, on the appointment of the right person to Redman ‘s Chair of Astrophysics, as this person would be overall head of the merged institution. The advertisement for the post specified an observational astronomer with an interest in instrumentation, and Hoyle had a candidate in mind: Wal Sargent. Sargent had made valuable contributions to astronomy in California, and had been an ally for Hoyle on the Northern Hemisphere Review.
On the loose
Authors: Gregory Jane
Published: November 2023

Cambridge no longer felt like home. The Hoyles considered where they might live instead, and settled on a remote house on Cockley Moor near Ullswater in the Lake District. It was the region whereHoyle had courted Barbara in 1939 and where they had spent many holi- days since. The Cambridge Evening News, the local paper that had followed Hoyle ‘s career, illustrated its report of the move with a photograph of his now empty armchair by the big window – Hoyle ‘s ‘window on the world ‘, said the paper – in the living room at Clarkson Close, and pointed out the worn patch of carpet in front of the chair where Hoyle ‘s feet had left their mark.1 Barbara wrote to their friends telling them of the new job with Bernard Lovell at Jodrell Bank, and enclosing a copy of the newspaper article.
Apocalyptic visions
Authors: Gregory Jane
Published: November 2023

The Hoyles abandoned Britain ‘s driest summer for decades for a road trip around the USA, from California to Minnesota, Connecticut, Kentucky, and on to California, in a car stuffed with maps and guidebooks and organized for them by Caltech colleagues. By November, Hoyle was lecturing in Hawaii. When they returned to their remote lakeland home, Hoyle contributed to a BBC television programme called ‘According to Hoyle, ‘ and in an accompanying article in the Radio Times his former student John Taylor of King ‘s College London hinted that the isolation of Hoyle ‘s retirement was beginning to tell on him: having ‘apparently dropped out of British science ‘, he no longer enjoyed the checks and balances provided by a community of critical colleagues.
A new cosmology
Authors: Gregory Jane
Published: November 2023

After 15 years in the rugged landscape and capricious weather of the Lake District, the Hoyles were finding life less comfortable in their isolated home. So in 1988 they moved to Bournemouth, aseaside town on the south coast of England much favoured by tourists and retirees for its sandy beaches and gentle climate. They had found a spacious flat on top of the cliffs, with broad views over the sea; and Hoyle settled into an armchair by the living room window. Despite his great enthusiasm for computers as calculating machines, he never took to the PC: he preferred the pad of lined paper that had been his chalkboard and medium throughout his career.
Magnetization vs. temperature
Authors: Aharoni Amikam
Published: November 2023

Before continuing with the theories, it seems necessary to pause and explain why the molecular field approximation of chapter 2, the spin wave series for low temperatures of chapter 3, as well as all other theories of Mz(T), are restricted to the case H = 0.
Basic Micromagnetics
Authors: Aharoni Amikam
Published: November 2023

It can be concluded from the last chapter that there is no way to neglect any one of the three energy terms, exchange, anisotropy, and magnetostatic, and all three must be taken into account in any realistic theory of the magnetization processes. It would have been nice if the other terms could be added to the Heisenberg Hamiltonian, at least as a perturbation.
Tactics of obligate brood parasites to secure suitable incubators
Authors: Sealy S G , Mcmaster D G , Peer B D
Published: November 2023

Obligate brood parasites lay all of their eggs in the nests of other species (Payne 1977a; Rothstein 1990), but some females of many other species that typically incubate their own eggs and care for their young also lay parasitically, in nests of their own or of other species (Yom-Tov 1980a; Rohwer and Freeman 1989; Sorenson 1991; Saylor 1992; Slagsvold 1998). A remarkable array of adaptations enables these brood parasites to lay their eggs in nests of unrelated individuals, delegating incubation, feeding and early defence of all or some of their young to foster parents, or hosts.
Urban Ecology
Authors: Whitten Tony , Damanik Sengli J , Anwar Janzanul , Hisyam Nazaruddin
Published: November 2023

Sumatran towns are not nearly as interesting ecologically as they could be because their vegetation is largely foreign and therefore supports few birds, squirrels and other animals. Many of the larger animals that are able to live in Sumatran towns are shot as soon as they are in the sights of an air rifle and inappropriate pesticide use probably also takes its toll. Towns in India are often home to large numbers of animals, including monkeys and squirrels, because the human inhabitants have a religious respect for these forms of life. India is a useful comparison, because the high human population density and the effects of development there cause more serious environmental problems than currently exist in Sumatra.
Negative Phenomena Induced by TMS of Human Primary Motor Cortex
Authors: Ziemann Ulf
Published: November 2023

This chapter will focus on transient functional lesions that can be produced by transcranial magnetic stimulation (TMS) of human primary motor cortex. The text is divided into two main parts. The first part will deal with TMS-induced motor cortex inhibition. This is a purely physiologic and nonbehavioral approach. Motor cortex inhibition is defined here as a reduction in motor evoked potential (MEP) size. The second part will report on TMS-induced interference with motor performance. This is a behavioral approach. The two parts are tightly linked with each other: knowledge about the physiology of motor cortex inhibition may lead to a better understanding of negative modulation of motor cortex output on the behavioral level.
Cerebral Control of Eye Movements
Authors: Segraves Mark A
Published: November 2023

As has been the case for all of the functional systems considered in this book, investigations of the role of the cerebral cortex in the control of eye movements with “virtual lesions” were preceded by experiments where surgical removal of a region of cortex was followed by behavioral testing to determine the ability of the subject to make eye movements in the absence of that area. We now understand that studying the behavior of an animal after a region of cortex has been removed is not so much a study of the function of the role of that missing cortex as it is a study of the ability of the brain to compensate for the loss of that cortex (Lomber 1999). Studies of this sort may reveal components of behavior for which a particular cortical area is absolutely essential. The extensive reorganization and compensation that must take place following cortical damage, however, ensures that studies of postlesion behavior provide sparse insight into the role of the damaged region in the normal, intact brain.
An overview: How Infection Began and Became Disease
Authors: Greenblatt Charles L
Published: November 2023

When professionals are in panic, the layman has every right to be concerned. The events of September 11th 2001, followed by the successful use of the anthrax bacillus as a weapon of bio terrorism struck fear into the hearts of many, including the public health professionals to whom we entrust our care. Those dramatic events can be seen against a background of a general dispair concerning the capabilities of physicians to handle infectious diseases. The inability to cope with anthrax was just a special case of modern science’s failure to deal with one of our great natural enemies, the microbe. Today, many physicians are as stirred up by antibiotic resistance as the mother whose child does not respond to treatment. When the town council of a posh New York City suburb is up in arms over West Nile fever, the general practitioner and local public health official are as distraught as the ordinary citizen. Thus the whole medical establishment is seriously occupied with what the next plague has in store for us – whether unleashed by bio-terrorists or by mother nature (Garrett 1994).
The Microbiology of Amber: a Story of Persistence
Authors: Cano Raul J
Published: November 2023

Until 1984 (Higuchi and Wilson 1984), the isolation and characterization of fossil DNA was considered unattainable, as the methodologies for extracting minute quantities of partially degraded DNA and their subsequent enzymic amplification were not available. With the advent of the polymerase chain reaction (PCR) (Mullis et al.1986), a new analytical tool became available for the molecular study of fossils. It is now possible to conduct molecular studies of extinct organisms or fossils, utilizing their DNA to unravel biological and evolutionary questions. The value of fossil evidence is that it may demonstrate the condition of taxa before evolutionary divergence obscured phylogenetic relationships. Because they are older, ancient fossil DNA sequences should be less divergent than extant sequences and should therefore have value for relating more derived extant taxa. When compared with extant DNA, ancient DNA sequences may also provide an insight into the pattern of molecular evolutionary change through time. In this light, ancient DNA could provide invaluable information on the evolution and epidemiology of infectious diseases. Understanding the evolution of virulence and the acquisition of virulence factors by microbial populations could help in identifying microorganisms that are likely to become ‘emerging’ pathogens, as well as in creating methods to arrest the development of pathogenic potential for those organisms.
Evolution of Arthropod Disease Vectors
Authors: Black IV William C
Published: November 2023

Fossils resembling arthropods first appeared during the late Proterozoic about 600 to 540 million years ago. Today the phylum Arthropoda contains∼80% of all extant metazoan animal species, and arthropods have come to occupy virtually every marine, freshwater, terrestrial, and aerial habitat on earth. Arthropods are also essential components of most of the major food chains. In many ecosystems arthropods consume and recycle detritus and the associated bacteria, algae, and fungi. Many species consume either the living or dead tissues of terrestrial and aquatic plants and animals. Many are voracious predators or parasites. Given this huge taxonomic and ecological diversity, it is not surprising that a small proportion of arthropods have evolved the ability to utilize a rich and abundant source of nutrients, the blood of vertebrates.
Kinetic formulation of multidimensional scalar conservation laws
Authors: Perthame Benoît
Published: November 2023

In this chapter we consider scalar conservation laws (SCLs in short). The problem consists in finding a function u(t, x) defined for t ≥ 0, x = (x  1, x  2,..., x  d) ∊ ℝd , and which solves the nonlinear quasilinear equation.
Kinetic schemes for gas dynamics
Authors: Perthame Benoît
Published: November 2023

We consider again the system of isentropic gas dynamics treated in Section 1.4 and Chapter 7. We recall that it is given by two equations that express physically the conservations of mass and momentum for a barotropic gas, which we again complete by the entropy inequality for the total energy.
Origin Of Microstructure
Authors: Bhattacharya Kaushik
Published: November 2023

In the previous chapter, we saw that twins can be obtained as energy minimizing deformations. However, it is unusual to see isolated twin interfaces in martensitic materials. Instead, typical sections of martensitic materials, like those in Fig. 1.1(a), show complex patterns with many interfaces. Furthermore, the length-scale of these patterns is much smaller than that of the specimen.
Piecewise Linear Elasticity
Authors: Bhattacharya Kaushik
Published: November 2023

We now turn to a special case of the geometrically linear theory that is commonly used in the literature since it enables easy computation. The basic idea is to model or approximate the energy density as a piecewise quadratic function, so that the martensitic material may be treated as a composite material made of linear elastic materials with different residual strains.
Polycrystals
Authors: Bhattacharya Kaushik
Published: November 2023

So far, we have studied the martensitic transformation and the shape-memory effect in single crystals where the reference lattice or the lattice of the high-temperature parent austenite phase is uniform across the specimen. However, typical commercial specimens are polycrystals: they are an agglomeration of a very large number of crystals or grains each of which is made of an identical lattice whose orientation can change from grain to grain.
Supergravity
Authors: Binétruy P
Published: November 2023

There are two directions one might take to generalize supersymmetry and its models as we have presented them until this point: (a) to try to incorporate gravity as the fourth fundamental interaction, or (b) by using our experience with gauge theories, to try to make supersymmetry local. It turns out that these two attempts converge: local supersymmetry makes it necessary to introduce a graviton field (and its supersymmetric partner the gravitino) and therefore gravity. Thus the theory of local supersymmetry is called supergravity.
Phenomenology of supersymmetric models: supersymmetry at the quantum level
Authors: Binétruy P
Published: November 2023

Since the Standard Model has been tested to a level where quantum corrections play an important roˆle, it is expected that any theory beyond it will have to be tested at the same level. From this point of view, the odds are in favor of supersymmetric theories since supersymmetry has been constructed from the start to control quantum corrections. Since this chapter deals with the confrontation of supersymmetry with the real world, we first discuss in some detail this important issue of stability under quantum corrections. Obviously, supersymmetry is broken. The way supersymmetry is broken should have some decisive impact on the search of supersymmetric particles. We thus review the main scenarios of supersymmetry breaking, mostly from a phenomenological point of view. More theoretically oriented issues are postponed till Chapter 8.
Supersymmetry and the early Universe
Authors: Binétruy P
Published: November 2023

The introduction of supersymmetry allows us to introduce new physics with a fundamental mass scale which is very large. A certain number of observations plead for such a possibility, among which the value of gauge couplings compatible with unification and the scale of neutrino masses. More generally the fact that fundamental physics is described by gauge theories, which are known to dominate in the infrared (i.e. low energy) limit, tends to accommodate the idea that the scale of underlying physics is much higher. There are indirect ways to test at low energy a theory with a large fundamental scale, through effective interactions which scale like inverse powers of the fundamental scale. The best-known example is proton decay: an excessively rare event because the corresponding amplitude scales like the inverse of the square of the grand unification scale. On the other hand, there is no hope to construct accelerators that would reach the desired mass scales to test these theories directly. One has to resort to natural cosmic accelerators or to the study of the early Universe , in which, at least in the hot Big-Bang scenario, temperatures have reached high enough values to excite super heavy degrees of freedom.
HVPE-GaN quasi-substrates for nitride device structures
Authors: Paskova Tanya , Monemar Bo
Published: November 2023

The development of III-nitride semiconductor devices for optoelectronic and electronic applications is driven by improvements in the epitaxial growth of these semiconductor materials. Device structures have traditionally been obtained using either MOCVD or MBE in many semiconductor material systems. The present device applications for III-nitrides have used MOCYD (particularly in the commercially work at Nichia Chemical [1] and Cree Research [2]) and MBE growth has lagged behind for optoelectronic device applications. However, recent developments in the MBE technology result in improved material quality and make the competition between them sharper. Moreover, the best quality MBE layers have been obtained using MOCYDGaN templates [3], indicating that a combination of different growth techniques may be a way for producing the next generation III-nitride materials.
The growth of low-dimensional nitrides by molecular beam epitaxy
Authors: Grandjean Nicolas , Damilano, Benjamin , Massies Jean
Published: November 2023

Molecular beam epitaxy (MBE) is the technique of choice for the growth of low-dimensional semiconductor hetero structures. The ultra-high vacuum environment of MBE allows the use of an in situ electron probe like reflection high-energy electron diffraction (RHEED). RHEED is a powerful tool for controlling the growth in real time [1]. It allows the precise measurement of the growth rate [2), the determination of ternary alloy composition [3), and the investigation of strain relaxation during heteroepitaxy [4, 5). MBE is also well suited for achieving abrupt interfaces. This is the consequence of molecular flux regime, which authorizes an instantaneous flux switching (simply using a shutter), and growth conditions far from equilibrium that avoid strong intermixing at the interfaces. For instance, the substrate temperatures used in MBE are much lower than those currently reported for metal-organics chemical vapor deposition (MOCVD) growth.
GaN-based modulation doped FETs
Authors: Morko Hadis , Carlo, Aldo Di , Cingolani Roberto
Published: November 2023

Because of their large bandgap, large high-field electron velocity, large breakdown field, large thermal conductivity, and robustness, GaN and its hetero structures with InGaN and AlGaN have recently attracted a good deal of attention for high power/high temperature electronics applications, and for use in optoelectronic devices operative in the UV and visible wavelengths. Specifically, the hetero structures based on GaN have paved the way to AlGaN/GaN MODFETs with CW power levels of about 6 W at 10 GHz in devices with 1 mm gate periphery which are comparable to power densities extrapolated from smaller devices. This means that the 1-mm devices are not thermally limited yet. On the noise figure front, a minimum noise figure of 0.85 dB with an associated gain of 11 dB at 10 GHz has been obtained. The expected electron mobility in GaN has recently been upgraded from a maximum of about 900cm2v-1s-1 to about 2000cm-2v-1s-1, which bodes very well for electronic device applications. While the experimental device effort is progressing well, basic issues such as polarization-induced charge has gained prominence as it is inextricable from charge induced/controlled by the gate. Last but not least, the GaN-based material system, though far from being perfected, has already demonstrated remarkable performance in optical emitters optical detectors, which are not discussed in this review.
Neutron production and detection: the nuts and bolts
Authors: Higgins Julia S , BenoÎt Hendri C
Published: November 2023

Attempts to compare different methods of producing neutrons for scattering experiments invariably give rise to problems since the effectiveness of a given source depends on the particular experimental technique being used in the experiment. One general statement can be made about all sources—they are relatively very weak.
Spectrometers and what they measure
Authors: Higgins Julia S , BenoÎt Hendri C
Published: November 2023

Any reader who has just ploughed through Chapter 2 and now reads the title of this chapter could be forgiven for wondering when we are going to get to the ‘meat’ and discuss scattering from polymers. It is true that the previous chapter could have its place in any work on neutron scattering. On the other hand, omission of the material it contains could result in an irritating lack of completeness. In this chapter we will narrow the field of view and concentrate attention on the relatively few types of spectrometer with significant numbers of applications to polymer systems. Without this limitation, the sheer variety of neutron sources and applications would lead to a very extensive volume.
Dynamic Response Functions
Authors: Glyde Henry R
Published: November 2023

In this chapter we discuss the properties of liquid and solid helium observed in neutron scattering measurements and the functions used to describe these properties. The general theory of neutron scattering is set out by Marshall and Lovesey (1971) and Lovesey (1971), Lovesey (1984), Price and Sköld (1986), Egelstaff (1992), and many others. We focus on the functions describing the density excitations, spin density excitations, phonons, and single-particle excitations in helium. These are the dynamic structure factor, S(Q, ω;), and the corresponding dynamic susceptibility, x(Q, ω), describing density and spin density excitations, where hQ and hω are the momentum and energy transferred from the neutron to the target; and single-particle Green functions describing phonon and quasiparticle excitations. We outline the general properties of these functions and the sum rules they obey to set the stage for the book.
Observed Properties Of Liquid 4He Liquid 4
Authors: Glyde Henry R
Published: November 2023

Liquid 4He is the most accessible Bose fluid in nature. Its structure and excitations have therefore been widely investigated using neutron scattering and other techniques, the topic of this chapter. Early measurements are touched on in §9.5 and are superbly reviewed by Woods (1965).A next generation of experiments followed. These measurements, including light scattering and sound transmission measurements, mapped out the basic static and dynamic properties of liquid 4He. This data and its interpretation are authoritatively reviewed by Woods and Cowley (1973). This review, the paper by Cowley and Woods (1971), and the subsequent data by Dietrich et al. (1972) and Graf et al. (1974) provide a complete account of the field up to the mid 1970s. These papers set the stage for the present chapter and are highly recommended.
Excitations In Liquid 3He
Authors: Glyde Henry R
Published: November 2023

In this and the following five chapters we discuss the study of excitations in normal liquid 3He by neutron scattering. Liquid 3He is the prototype, monatomic Fermi liquid in nature. Understanding its fascinating properties is therefore a fundamental issue in quantum physics. This understanding can also be applied to more complicated Fermi liquids such as electrons in metals, superconductivity, and to protons and neutrons in nuclei.
Detectors and spectrometers of UCN
Authors: Ignatovich V K , Pontecorvo G B
Published: November 2023

Detectors of UCN are based on the same principle as conventional neutron counters, namely they contain a substance called the radiator, the nuclei of which absorb neutrons and subsequently decay, emitting charged particles. The charged particles are then registered either by their tracks (track detectors), or by light flashes (scintillation detectors), or with the aid of electric discharges (proportional counters and solid-state detectors).
The application of UCN
Authors: Ignatovich V K , Pontecorvo G B
Published: November 2023

UCN can be utilized as tools for investigations of fundamental problems (studies of the properties of the neutron itself) and in applications (studies of substances). We shall first discuss the fundamental problems.
Why robots
Authors: Holland Owen , McFarland David
Published: November 2023

In this chapter we address the more general questions relating to the use of robots in biological research. Much of the material in this chapter comes from discussions arising at the Artificial Ethology Workshop in 1998.

During the discussions we attempted to answer the following questions:

Although there is clearly a degree of overlap between some of these questions, they provide a useful way of structuring a discussion of the value of robots to biology.
Tensor Product Spaces
Authors: Wasserman Robert H
Published: November 2023

We will describe the space of bilinear functions on a pair of finite-dimensional vector spaces as the tensor product space of the duals of those two vector spaces. We then consider tensor product spaces of more than two vector spaces. Finally we define tensor product spaces in the general case so that they reduce to spaces of multilinear functions in finite dimensions.
Tensors
Authors: Wasserman Robert H
Published: November 2023

We restrict our attention to tensor products of a single vector space, V, with itself and with products of V*. We look, in these special cases, at the isomorphisms, and representations in terms of components we discussed in Chapters 2 and 3. Finally, we will describe several important mappings of these spaces.
Differentiable Manifolds
Authors: Wasserman Robert H
Published: November 2023

At the beginning of Chapter 7 we mentioned that for the description of physical phenomena we have to generalize the concept of maps between cartesian spaces to those between more general domains and image spaces. We want to keep the domain as general as possible; i.e., with as little structure as possible. This is the perspective that motivates the study of sets on which local coordinates are defined. After general definitions, examples, and a brief discussion of mappings we impose the structures of Sections 7.2 and 7.3 on manifolds.
Integrability Conditions for Distributions and for Pfaffian Systems
Authors: Wasserman Robert H
Published: November 2023

We can generalize the discussion above by means of the observations following Theorem 13.9.
Connections on Manifolds
Authors: Wasserman Robert H
Published: November 2023

In Section 16.3 we defined what we mean by a manifold with a linear (or affine) connection. We made the definition in terms of local 1-form fields. There are several other ways of describing connections. We will first present two of these, and then describe the most important structures arising out of a connection on a manifold.
Mechanics
Authors: Wasserman Robert H
Published: November 2023

Our exposition of geometry in Chapters 15, 16, and 17 consisted of starting with a manifold and superimposing a symmetric tensor field of type (0, 2), or prescribing a covariant derivative for vector fields, and then studying the properties of such abstract structures. A motivation for each generalization and abstraction is that it includes as a special case the classical well-established geometry with which we are familiar.
Symplectic Manifolds
Authors: McDuff Dusa , Salamon Dietmar
Published: November 2023

This is a foundational chapter, and everything in it (except perhaps Section 3.4 on contact structures) is needed to understand later chapters. The first section contains elementary definitions and first examples of symplectic manifolds. The second section is devoted to Darboux’s theorem. Some situations are flexible and there are no nontrivial invariants, while other situations are rigid. In this chapter we deal with ‘soft’ phenomena, the fact that in symplectic geometry there are no local invariants. The classical formulation of this principle is known as Darboux’s theorem: all symplectic forms are locally diffeomorphic. However there are many other related results, such as Moser’s stability theorem and various versions of the symplectic neighbourhood theorem.
Ion excitation: ion beam spectrochemical analysis (IBSCA) and glow discharge optical spectroscopy (GDOS)
Authors: Riviere J C
Published: November 2023

Although these two techniques depend on rather different physical mechanisms, they are discussed together here since the one thing that they have uniquely in common is identification of sputtered species by spectroscopic analysis of light in the visible region. They bear approximately the same relationship to each other as do SSIMS and GDMS, to be the subjects of following chapters.
Lattice dynamics
Authors: Dobbs E R
Published: November 2023

In this chapter we outline the development of a theory of solid helium as a quantum solid, that is, one in which the zero point energy Ezis roughly equal to the static potential energy U0, in contrast to classical solids where Ez≪ U0First, we discuss the important differences between the environment of an atom in a classical solid like argon with those of an helium atom in a quantum solid, although in both cases their interatomic pair potentials can be approximated by the well-known Lennard-Jones (12, 6) potential.
Low-dimensional structures
Authors: Dobbs E R
Published: November 2023

Studies of the adsorption of He on a variety of surfaces, but especially on graphite, have provided a wealth of information on the behaviour of two-dimensional (2D) quantum solids and their interactions with substrates. In this chapter, the establishment of a phase diagram for a monolayer of He from heat capacity measurements is followed by accounts of recent studies of the magnetic and thermal properties of the first, second, and higher layers of He on graphite. Finally, some interactions of 2D He with other substrates are discussed.
The historical and scientific perspective
Authors: White Guy K , Meeson Philip J
Published: November 2023

It is said that survival sharpens the mind. Many low-temperature techniques evolved from this beginning. The eskimos found that a finely divided air-hair mixture provided very effective thermal insulation in the Arctic winter. Likewise the desert arab found multilayers—fabric and airspace—helped him survive the summer. We understand there is also an old Arab saying that ‘light is heat’—their homes provided good radiation protection by having no unshuttered windows! The earliest cooling systems were probably evaporative, letting water slowly seep through ceramics and evaporate in hot dry surroundings. To this day a canvas water bag carried on a car bumper bar or around a camel’s neck is a boon to the summer traveller in hotter climates. A larger version used in the Australian hinterland for a hundred years or more, was a box or whole room covered in hessian cloth and continually kept moist by a capillary-drip system to preserve food. This was locally called the Coolgardie safe by the early gold miners in an arid part of Western Australia. In other climates like Europe or northern America where winters are extreme, the inhabitants cut and stored the winter ice in underground caves or huts which were well insulated with earth and straw or sawdust.
Heat transfer
Authors: White Guy K , Meeson Philip J
Published: November 2023

A determination of the physical properties of materials at temperatures which are different from the surrounding temperature requires thermal isolation of the material from its surroundings; the degree of isolation must be sufficient to meet the demands of temperature control, temperature measurement and, in the case of low-temperature research, the available refrigerating capacity of the coolant. In general, heat may be transferred by conduction, convection, and radiation. In most low-temperature applications, convection is not significant because of the partial evacuation of gas from the interior of the cryostat. Effective heat transfer takes place by conduction through the residual low-pressure gas, conduction through the solids that interconnect the various parts of the cryostat, and by radiation. In addition such factors as Joule heating in electrical leads, eddy current heating, mechanical vibration, absorption or desorption of gases may contribute to the heat transfer.
Temperature control
Authors: White Guy K , Meeson Philip J
Published: November 2023

It is almost always the case in the course of experimentation at low temperatures that the experimenter not only wishes to know the temperature of the sample whose properties are to be measured but also wishes to achieve a particular sample temperature and wishes to hold that desired temperature for some useful length of time. The experimenter will also want to know that the required temperature has been obtained to within some specified accuracy for the duration of any particular measurement. Generally experiments need to be performed over a range of temperatures in order to determine, for instance, whether a sample has some particular power law or exponential dependence of its properties on temperature. Information such as this is often particularly revealing of the physics of the sample. For example, it may be possible to design an experiment to measure the thermal conductivity of some sample in which the absolute value of the thermal conductivity is not well determined because of some unknown factor, such as an irregularly shaped sample. Under such circumstances it is still possible to determine the temperature dependence of the thermal conductivity to a rather high degree of accuracy, because the unknown parameters are precisely constant and may be factored out. Conversely, it is important in such circumstances to make measurements over a sufficiently large range of temperature (given some finite indeterminacy or error bar in any one measurement at any one temperature) to ascertain any supposed power law with sufficient confidence. Finally, we do not wish to see any instability in the temperature being the major contributor to uncertainties or errors in the final value obtained from a measurement.
The evolution of gene regulation: approaches and implications
Authors: Bergman Casey M , Patel Nipam H
Published: November 2023

Since the earliest days of molecular biology, there has been increasing interest in understanding the role of transcriptional regulation in the morphological evolution of higher organisms. This trend owes its origin to the pioneering insight from studies of the lac operon which demonstrated that modern genomes contain DNA sequences devoted solely to the regulation of other genes (Jacob and Monod 1961). These sequences were shown to be closely linked in “cis” to the gene(s) under transcriptional regulation and function as the targets of “trans” acting factors. These cis-regulatory sequences were immediately regarded as being potential targets of functional change exerted by evolutionary forces such as mutation, selection and genetic drift.
Mass extinctions and evolutionary radiations
Authors: Erwin Douglas H
Published: November 2023

Mass extinctions are a critical driving force for evolutionary change. Whether the patterns of extinction are random or selective, they prune the tree of life and the subsequent evolutionary rebounds provide an opportunity for previously minor clades to become dominant, for dramatic reorganizations of ecosystems, and for the appearance of significant evolutionary innovations. Not all mass extinctions trigger such reorganizations, however. Some have relatively little long-term influence on the course of evolution. Yet, however much we may regret the current, human-driven loss of biodiversity, the fossil record clearly demonstrates the evolutionary impact of mass extinctions.
Could there be a Darwinian account of human creativity?
Authors: Dennett Daniel C
Published: November 2023

Weaverbirds create intricate nests; sculptors and other artists and artisans also create intricate, ingenious constructions out of similar materials. The products may look similar, and outwardly the creative processes that create those processes may look similar, but there are surely large and important differences between them. What are they, and how important are they? The weaverbird nestmaking is “instinctual,” and “controlled by the genes” some would say, but we know that this is a crude approximation of a more interesting truth, involving an intricate interplay between genetic variation, long-term developmental and environmental interaction and short-term environmental variation—in opportunities and materials accessible at the time of nest building.
Statistical mechanics and thermodynamics
Authors: Yeomans J M
Published: November 2023

This chapter moves through the large number of reminders and definitions necessary to arrive at the point where we can introduce the idea of universality, one of the most striking features of the theory of critical phenomena and a major justification for the interest in model systems. The first step is to summarize the statistical mechanics used throughout the book. Assuming that this is familiar material the main aim will be to gather together the relevant formulae in a form suitable for reference.
Mean-field theories
Authors: Yeomans J M
Published: November 2023

Very few statistical mechanical models have been solved exactly. In three dimensions not even the nearest neighbour spin-1/2 Ising model is tractable. Therefore it is necessary to resort to approximation methods. One of the most widely used of these is mean-field theory. A systematic way of deriving the mean-field theory for a given microscopic Hamiltonian is to start from the Bogoliubov inequality This gives the best possible approximation to the true free energy for a given choice of Ho because the inequality (4.1) insists that the meanfield free energy cannot fall below the true free energy. (This is analogous to the variational principle in quantum mechanics.) The usual choice for Ho is a free Hamiltonian -one with no interactions-as this enables explicit calculation of the right-hand side of (4.1).
Monte Carlo simulations
Authors: Yeomans J M
Published: November 2023

It could be argued that current physics research can be divided into three areas-theoretical, experimental, and computational. umerical approaches, in which systems are mimicked as accurately as possible using a computer or in which computer models arc set up to provide well-behaved experimental systems are increasingly providing a bridge between theory and experiment. The limitations on what can be clone are set by the computational resources available.
Theoretical Frameworks Relevant for GR Studies
Authors: Harakeh M N , van der Woude A
Published: November 2023

In the first chapter the occurrence of GRs in nuclei was discussed. These can be understood as collective excitations of a quantum many-body system, in this case the nucleus. GRs can be described as the response of the nucleus to a weak external field, such that a linear approximation can be applied. This field can be decomposed into various multipoles and the response can thus be viewed as the sum of the various contributions of the multipole GRs. The definition of GRs stems from the observation of the dominant GR structure in photo-absorption spectra, now known as the isovector giant dipole resonance (IVGDR). However, GRs of various multipolarities are common features of excitation of the nucleus. They occur systematically for all nuclei across the mass table, and their macroscopic properties such as excitation energy and width vary smoothly as a function of the atomic mass number A. Furthermore, they exhaust a large fraction of the transition strengths (sum rules) connected with the multipole transition operators of the external fields responsible for their excitation.
Spin of the Neutron
Authors: Alexandrov Yu. A , Drozdova T F
Published: November 2023

The spin of the neutron is (in units of h). The neutron obeys Fermi-Dirac statistics. These statements are based on a great deal of experimental data and need no further confirmation.Let us briefly discuss the main facts in favour of the value of for the neutron spin.
Electric Charge of the Neutron
Authors: Alexandrov Yu. A , Drozdova T F
Published: November 2023

The question of the existence of the electric charge of the neutron is closely connected with the general question: why are the charges of all elementary particles equal to ± Q  e, where Q  e is the charge of the electron, or to zero?† The neutron is conventionally assumed to be neutral, but it is not theoretically forbidden for it to have a small electric charge, so an experiment on a search for it might be of extreme interest.In the modern theory of elementary particles the laws of conservation, for example of electric, baryonic, and leptonic charges, play an important role. Their validity has been tested experimentally to great precision, and no case of their violation has been observed to date. They are believed to be ‘absolute’, that is to hold for all three types of elementary particle interactions (strong, electromagnetic, and weak). Together with the laws of conservation of energy, momentum, and angular momentum they govern the interaction of elementary particles.
Electromagnetic Structure of the Neutron
Authors: Alexandrov Yu. A , Drozdova T F
Published: November 2023

The urgency to develop ideas of the structure of objects comes from the natural desire to understand the infinite variety and complexity of the visible world as the outcome of an enormous number of possibilities available to a small number of fundamental entities subjected to fundamental laws of behaviour.The atomistic character of the macro world was first proposed by the ancient philosophical school, but physical phenomena and the mechanical, thermal, or other properties of gross matter were only well understood in terms of the atomistic concept after the creation of kinetic theory and statistical mechanics. In the late nineteenth and early twentieth centuries it became clear that atoms themselves were not irreducible but consisted of even smaller objects, that is electrons and nuclei. From this viewpoint one can easily explain the whole variety of phenomena and the dynamics of processes going in an atom: quantized energy levels, scattering of charged and neutral particles, etc. It is correct to some extent to speak about the neutron-proton structure of the nucleus. However, this structure has a more dynamical character than atomic structure. Finally, quite a new situation is encountered in the consideration of the structure of elementary particles: whereas the atom and in large measure the nucleus itself could be considered to be composed of electrons, protons, and neutrons as essentially permanent constituents, for the internal structure of elementary particles one is forced to admit the existence of unobservable virtual particles created from a certain period of time defined by the Heisenberg uncertainty principle and existing only to carry a specific interaction. This radically new approach to the problem has appeared possible only with the development of quantum mechanics.
Neutron-Neutron Scattering
Authors: Alexandrov Yu. A , Drozdova T F
Published: November 2023

The experimental determination of the neutron-neutron scattering length is of interest from the point of view of both the study of nucleon-nucleon interactions and the verification of the hypothesis of isotopic invariance of strong interactions at low energies. Since nuclear reactors at present produce a maximum neutron density of no more than 1011 cm−3, direct measurements of neutron-neutron scattering are still a matter of discussion. All the information currently available on the interaction between two neutrons has been obtained from indirect measurements that are reduced to a study of the effect of the neutron-neutron interaction on the spectrum from the reaction resulting in the formation of three particles. Before considering such experiments let us discuss some aspects of the hypothesis of charge independence of nuclear forces.
The Antineutron
Authors: Alexandrov Yu. A , Drozdova T F
Published: November 2023

An antiparticle was first identified in cosmic rays by Anderson in 1932. It was a positron. However, a quarter of a century was to pass before it was discovered that the Bevatron, which accelerated protons to 6 GeV, produced antiprotons (1955) and antineutrons (1956).Antineutrons were found by Cork et al.  [391]
Basic characteristics of semiconductors
Authors: Balkanski M , Wallis R F
Published: November 2023

The history of semiconductors dates back to the nineteenth century. The decrease in resistance of silver sulfide with increasing temperature was noticed by Michael Faraday (1833). Selenium was found to be photo-conducting by W. Smith (1873), and the rectifying properties of lead sulfide were observed by F. Braun (1874). During World War II silicon found application as a rectifier in radar. By far the most important event, however, was the discovery of transistor action in germanium by J. Bardeen and W. H. Brattain in 1948, which ushered in the explosive development of high technology based on semiconductors that continues to the present day.
Electronic energy bands: basic theory
Authors: Balkanski M , Wallis R F
Published: November 2023

Although applications such as rectifiers that we now associate with semi-conductors had been known as far back as the nineteenth century, it was not until after the development of quantum mechanics in the late 1920s that the physical basis for these properties became understood. A. H. Wilson showed in 1931 how the electronic band theory of crystals developed by F. Bloch can be applied to the understanding of semiconductors. Properties such as the negative temperature coefficient of electrical resistivity follow naturally from Wilson’s theory. The key ingredients are the Bloch states which are the eigenstates of an electron moving in the periodic potential of a crystal. The energies of the Bloch states cannot take on all possible values, but are restricted to certain allowed regions or bands separated from one another by forbidden regions or band gaps as shown in Fig. 2.1. The allowed energy bands are analogous to the pass bands of an electric transmission line and are characteristic of any wave propagating through a periodic structure (Brillouin 1953).
Semiconductor statistics
Authors: Balkanski M , Wallis R F
Published: November 2023

In order to calculate properties such as electrical conductivity, it is necessary to know the concentration of electrons in the conduction band and holes in the valence band. These current carriers can arise by thermal or optical excitation of electrons from the valence band to the conduction band, by excitation of carriers from impurity states, or by injection from an outside source. In this chapter we focus on carrier concentrations in a semiconductor in thermal equilibrium.