bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehension, Comprehensibility, and Learning in the Second Language Classroom
Authors: Chaudron Craig 
Published: November 2008

Two questions are fundamental to research on second language learning in instructional settings: (1) Does second language instruction have a positive influence on acquisition? and (2) If so, what factors in instruction make a difference, how, and for whom? This paper considers theory and research on second language classroom behavior that is aimed toward answering the second question, given evidence that the answer to the first one is affirmative.Theory suggests that the provision of comprehensible input, a focus on formal aspects of the target language, and the learner's opportunity to practice the target language, all may contribute to L2 development. Empirical research is reviewed to explore what modifications of teacher speech might influence comprehensibility, whether amount of exposure to target forms is related to learners' development, and which instructional behaviors might lead to productive practice with and knowledge about the target language.
What Causes Avoidance in L2 Learning
Authors: Laufer Batia , Eliasson Stig 
Published: November 2008

Among the structural and lexical factors claimed to account for avoidance in second language learning are (a) cross-linguistic difference, (b) cross-linguistic similarity, and (c) intrinsic complexity of the second language features avoided. This paper examines patterns of avoidance and preference for phrasal verbs or equivalent single-word verbs among Swedish learners of English. We assumed that if the subjects avoided English phrasal verbs, particularly the figurative ones, even though phrasal verbs exist in Swedish, this would indicate that inherent semantic difficulty of second language forms was the main factor contributing to the avoidance behavior. If, on the other hand, the learners did not show any preference for one-word verb forms in English, or indeed favored the phrasal forms, this would support the assumption that avoidance or nonavoidance depends largely on differences or similarities between the native and the foreign language.A multiple-choice test and a translation test were given to two groups of advanced Swedish-speaking learners of English. Each test consisted of 20 sentences, allowing for the choice of either a phrasal or a synonymous single-word verb. The test answers showed that the Swedish learners avoided neither phrasal verbs in general nor the figurative ones in particular, regardless of whether the verbs were similar to, or different from, their Swedish translation equivalents. Furthermore, the results were compared to the avoidance patterns of a group of advanced Hebrew-speaking learners of English. From the comparison it emerged that the Swedish learners usedsignificantly more phrasal verbs than the Israelis, notably figurative ones. These results suggest that the avoidance is determined more by a systemic incongruence between the first language (L1) and the second language (L2) than by the inherent difficulty of L2 forms.
The Role of Instrution in SLA
Authors: Lightbown Patsy M. , Spada Nina , White Lydia 
Published: November 2008

The papers in this issue were presented at a colloquium on The Role of Instruction in Second Language Acquisition held at Concordia University in Montreal, Canada, in July 1991. Participants in the Colloquium were the following:Birgit Harley, OISE, University of TorontoPatsy M. Lightbown, Concordia UniversityMichael Long, University of HawaiiManfred Pienemann, Sydney UniversityBonnie Schwartz, University of DurhamMichael Sharwood Smith, Utrecht UniversityNina Spada, McGill UniversityBill VanPatten, University of IllinoisLydia White, McGill UniversityThe Colloquium was sponsored by Concordia University and McGill University as well as by research grants from the government of Quebec through its Fonds pour la formation de chercheurs et l'aide à la recherche and from the Social Sciences and Humanities Research Council of Canada.
Jordan algebras spanned by Hermitian elements of a Banach algebra
Authors: Bonsall F. F. 
Published: November 2008

The Vidav–Palmer theorem [(11), (5), (2) (p. 65)] characterizes C*-algebras among Banach algebras in terms of the algebra and norm structure alone, without reference to an involution, in the following way. Let B denote a complex unital Banach algebra, and let Her (B) denote the set of Hermitian elements of B, that is the elements of B with real numerical ranges. In this notation, the Vidav–Palmer theorem tells us that ifthen B is isometrically isomorphic to a C*-algebra of operators on a Hilbert space, with the Hermitian elements corresponding to the self-adjoint operators in the C*-algebra.
Wave propagation in elastic rods with multiple wave speeds
Authors: Bachman R. C. , Cohen H. 
Published: November 2008

AbstractThis paper deals with the propagation and decay of nth-order displacement waves in linear hyperelastic rods having multiple wave speeds. The vector decay equation is integrated to find the explicit behaviour of all waves which can propagate in the rod. Examples are treated using a special form of the constitutive relations and results are given for rods of various geometries and wave multiplicities.
A nonstandard proof of the Riesz representation theorem for weakly compact operators on C(Ω)
Authors: Sun Yeneng 
Published: November 2008

AbstractAn easy way to construct the representing vector measures of weakly compact operators on C(Ω) is given by using the Loeb measure technique. This construction is not based on the Riesz representation theorem for linear functionals; thus we have a uniform way to treat the scalar and vector cases. Also the star finite representations of regular vector measures follow from the proof.
On the multiplicative structure of sections of vector bundles on an algebraic curve
Authors: Ballico E. 
Published: November 2008

AbstractHere we study (in a more general setting) the following problem. Let C be a smooth projective curve, E and F vector bundles on C and V ⊆ H0 (C, E) (resp. W ⊆ H0 (C, F)) vector spaces generically spanning E (resp. F); find lower bounds for the dimension of the image of the multiplication map V ⊗ W → H0 (C, E ⊗ F) generalizing the case rank(E) = rank(F) = 1.
A remark on metrically convergent series in F-spaces
Authors: Charsky H. M. 
Published: November 2008

Let X be an F-space, not necessarily locally convex, with a quasi-norm ‖x‖ (see (7), p. 31). The seriesof elements of X is commutatively convergent if and only if converges for every permutation {Yn}nεω of {Xn}nεω.
The general solution of the Low equation for KΛ-scattering
Authors: Lardner R. W. 
Published: November 2008

AbstractA derivation is given of the general solution of the static baryon Low equation for KΛ-scattering. This model has previously been used by Low to indicate possible ambiguities in the terms elementary and bound-state as applied to particles. The solution derived here can be used to establish this result from a general viewpoint which may possibly be applicable to more realistic models.
The effect of heat transfer on boundary-layer growth
Authors: Brown S. N. 
Published: November 2008

AbstractThe effect of heat transfer on boundary-layer growth is considered for the problem of a main stream of small Mach number which is instantaneously released past a heated cylinder, or alternatively the cylinder is accelerated impulsively into a stream at rest. In particular the effect of different values of the given wall temperature on the interval to separation and the thickness of the boundary layer is investigated. It is found that the former is decreased and the latter increased by the presence of heat transfer.
The order-types of central series
Authors: Hartley B. 
Published: November 2008

Letbe a series of type Ω of the group G. By this we mean that Ω is an ordered set (we shall always understand ‘ordered’ to mean ‘totally ordered’) and Λσ and Vσ are subgroups of G satisfying(i) Vσ ◃ Λσ for all σεΩ,(ii) Λσ ≤ Vτ if σ < τ(iii) , where G−1 denotes the set of elements ≠ 1 of G and Λσ−Vσ the set of elements of Λσ not belonging to Vσ,(iv) Vσ ≠ Λσ for all σ ε Ω.
The Problem of Relativity in reference to several bodies
Authors: Hargreaves R. 
Published: November 2008

§ 1. If the kinetic potential for the relative motion of two masses is written with an added constant asa close connexion with the relativity quadratic appears. The latter is in factwhere a modification of the primary formwhich shows an unaltered determinant. The condition in respect to the determinant, suggested, I believe, by Schwarzschild, is one which to me appears to give the most significant form to the results. From the dynamical standpoint we may regard it as imposing a counterpoise in the inertia coefficients to the modification introduced by the potential; or from a geometrical point of view we may regard it as minimizing the departure from the normal use of coordinates. An illuminating example of the loss of meaning that accompanies transformation in which this condition is disregarded is furnished by the isotropic form which is sometimes given to Einstein's quadratic.
On the Attenuation of Wireless Signals in Short Distance Overland Transmission
Authors: Ratcliffe J. A. , Barnett M. A. F. 
Published: November 2008

1. It is pointed out that the signal strength of a wireless wave at a distant point depends on:(a) the electrical constants of the ground,(b) the curvature of the earth,(c) the existence of an “atmospheric” ray coming downwards from the Heaviside layer.2. We can eliminate the effect of (b) and (c), and so obtain direct evidence about the electrical constants of the ground, by making measurements near the transmitter.3. Measurements on wave lengths of 300 m. and upwards give information about the resistivity of the ground, and on shorter wave lengths (15 m.) give the dielectric constant of the ground.4. Attenuation measurements have been made over short distances for wave lengths of 1600 m. and 360 m.5. The results are compared with those calculated from Sommerfeld's theory and show close correlation for distances beyond 10 wave lengths, but show deviations from the theory for shorter distances.They give as values for the resistivity of the groundp = 1·8 × 1013 E.M.U.for the Daventry signals, andp = 0·6 × 1013 E.M.U.for the London signals.
The propagation of radio frequency currents along a wire of finite length
Authors: White F. W. G. 
Published: November 2008

In the above paper it is pointed out that before we may use the usual wave equation for the propagation of current along a straight wire in free space it is necessary that (a) the inductance L and capacity C per unit length of the wire are independent of the current distribution and (b) that the product LC = 1/c2. This has been shown to be the case.The inductance and capacity of an element of a conductor are defined generally in the way suggested by Moullin and it is shown that the radiation resistance term, which is a function of the current distribution, is small compared with the corresponding terms involving inductance and capacity. The usual wave equation is derived from Maxwell's equations for the case of a tubular conductor in which the current is a function of the distance z along the conductor only. If the curl of the current is not equal to zero this will not represent the true state of affairs.It is pointed out in the earlier part of the paper that a complete solution of the problem, taking into account the radiation resistance, and the skin effect, involves the solution of an integral equation which is given.The field about a tubular current, with a current distribution J0 sin kz along it, is examined. It is found that, for a long wire, the electric force is perpendicular to the surface at every point since we neglect the contribution from the ends. The magnetic force is in circles about the axis as would be expected.A small component parallel to the current, and in phase with it, is introduced by the charges upon the ends of the tubular conductor, and this component determines the radiation resistance. From this it follows that the radiation resistance could be increased by placing a capacity on the ends—thus increasing the charges there.
Modified ionic states in crystals
Authors: Snow C. P. , Rawlins F. I. G. 
Published: November 2008

After a review of the magnetic and spectroscopic properties of compounds of the rare earth and of transitional elements of the first group, the types of bands in spectra of the latter are considered in detail. Reasons are advanced for the view that these are of “molecular” origin in ferric salts, but that the spectra of some transitional compounds contain lines which cannot be regarded in this way. Such lines are shown to be ionic, or quasi-ionic, and accord well with the suggestion of inter-combination transitions such as 4F—2G.The theoretical intensity conditions, as a function of multiplet intervals, are in agreement with the observed appearance of intercombination transitions in Cr, and possibly also in Mn and Co. Similar considerations apply to the rare-earth spectra. As an example we have shown that the strong absorption in Pr and Nd compounds, and the much weaker lines found in Sa and Eu, are in perfect agreement with the theoretical prediction of intercombinations.
Extension of a set of theorems in circle geometry
Authors: Grace J. H. 
Published: November 2008

The fascinating chain of theorems due to Clifford and recently extended by Mr F. P. White originates in the elementary fact that the circumscribing circles of the triangles formed by four lines meet in a point. From a like simple germ, namely the fact that the centres of the above-mentioned circles lie on a circle, an infinite chain of theorems was first evolved by Pesci and may be enunciated as follows:(i) The centres of the circumcircles of the triangles formed by four lines lie on a circle; thus from four lines we derive a point, namely the centre of the latter circle.(ii) Five lines give five sets of four and the five derived points lie on a circle; thus from five lines we derive a point, namely the centre of the latter circle.(iii) Six lines give six sets of five and the six derived points lie on a circle.
On chains of two-two relations and the theory of elliptic functions
Authors: Baker H. F. 
Published: November 2008

1. The relationin which we suppose each of a, b, c, a2 − c2 to be different from zero, leads, from a value θ, to two values of φ, which we may denote by θ1 and θ−1. Each of these, put in place of θ, leads, beside the value θ of φ, to another value of φ, say, respectively, θ2 and θ−2. If θ2 or θ−2 be put for θ, the same relation leads to two values of φ, say, θ1 and θ3 or θ−1 and θ−3, respectively. And so on. It may happen that θn is the same as θ, in which case also θ−n is the same as θ; this we may express by saying that the relation is closed, or that there is closure, after n links. It is the object of the present note to express in reduced form, in terms of a, b, c, the condition that this may be so. Evidently, if n = pq, the condition of closure after n links is satisfied when the condition for closure after p links (or also after q links) is satisfied. But there is a condition for closure after n links which is not satisfied for any less number of links; this is the condition which we call the reduced or proper condition for closure after n links, and it is this which we seek to express.
The Period of Decay of Radium B and Radium C
Authors: Bracelin P. 
Published: November 2008

Measurements of the saturation currents produced between two parallel plates by a source of radium C of carefully tested purity have been performed by an accurate galvanometer method. From the results a transformation constanthas been assigned to radium C corresponding to a half-value period of 19·72±·04 minutes.Similar measurements with radium active deposit have enabled a value to be estimated for the period of radium B between 26·7 and 26·8 minutes, which is the limit of accuracy of the experimental data.
The Cauchy property of the generalised Perron intergrals
Authors: Grimshaw M. E. 
Published: November 2008

1. Saks calls an integral complete if it satisfies two conditions, of which one, the condition (C), is as follows.If f(x) is defined in (a, b) and is integrable in each interval (a + ε, b − η), where a < a + ε < b − η < b, andexists, then f(x) is integrable in (a, b) and the integral over (a, b) is equal to the above limit.
On the Resolution of Cremona Transformations and particularly those of Genus One in Space of Three Dimensions
Authors: Babbage D. W. 
Published: November 2008

In the first section of this paper we illustrate the use that can be made of higher space in dealing with the problem of resolving a given Cremona transformation into the product of simpler Cremona transformations. In the second section we restrict ourselves to a particular large but finite class of Cremona transformations of [3], those of genus one, and show that these can all be built up from the four following simple types:(1) The bilinear transformation T3,3, determined by three equations bilinear in the coordinates of the two corresponding spaces; in the most general case of this both the direct and the reverse homaloidal systems consist of cubic surfaces passing through a non-degenerate sextic of genus three;(2) Three transformations Tn, n (n = 2, 3, 4) in which the homaloidal surfaces may in each case be obtained by taking in [4] a primal V of order n which has two (n− l)ple points, and projecting on to a given [3] from one of these points the sections of V by primes through the other; for n = 2 we have the familiar quadroquadric transformation determined by quadrics through a conic and a point.
Some Experiments on the Slowing Down of Neutrons by Collisions with Hydrogen Nuclei
Authors: Westcott C. H. , Bjerge T. 
Published: November 2008

The discovery of Fermi and his collaborators, that neutrons are much more readily captured by various atoms, e.g. silver, when their kinetic energies, originally of the order of 106 e.v., have been reduced by collisions with hydrogen nuclei, has been confirmed.The process of slowing down of the neutrons has been studied in some detail, and the nuclear cross-section for collisions with hydrogen nuclei has been determined for the primary neutrons and for the slow neutrons which are readily captured by silver atoms.The nature of the “gas” of slow neutrons was also discussed, but it was not found possible to reach a definite conclusion as to the energy of the neutrons concerned.
On the Phragmén-Lindelöf Principle
Authors: Srivastava P. L. 
Published: November 2008

In this short note my chief object is to prove the following theorem:If(1) f(z) is a regular function of z(= ρeiψ) in the angle |ψ| ≤ α, where ;(2) f(z)= 0(eαρ), where K is a positive constant, throughout this angle;(3) f(z) is not identically zero;then(4) is a continuous function of ψ for |ψ| < α.
On loci which have two systems of generating spaces
Authors: Richmond H. W. , Bath F. 
Published: November 2008

In hypergeometry loci defined by parametric equationshave been frequently discussed from various points of view. Among other properties these loci possess two systems of generating spaces obtained by keeping the α's (or β's) fixed while the β's (or α's) vary, the simplest example being the generators of a quadric in S3. Another method of obtaining loci having these properties is by taking the flat spaces through the sets of a linear series of sets of points on an elliptic curve and the flat spaces through the sets of the residual series (the curve being supposed normal. In this way we shall obtain a configuration of ∞PSP's and ∞qSq's, the dual of which gives a locus included among those represented by (1).
Extension of a Lemma of Stroh
Authors: Grace J. H. 
Published: November 2008

The lemma I propose to discuss may be stated as follows;If ξ, η, ζ are three quantities whose sum is zero and λ, μ, ν three positive integers (≤n) satisfying the conditionthen any polynomial of order n in ξ, η, ζ can be expressed in the formwhere P, Q, R are polynomials of orders n − λ, n − μ, n − ν.
On some series of functions, (1)
Authors: Paley R. E. A. C. , Zygmund A. 
Published: November 2008

Let c0, c1,…, cn,…be a sequence of real constants, and ƒ0(x), ƒ1(x),…, ƒn(x),… a sequence of functions defined, for example, in the interval (0, 1). In this paper we shall investigate some of the properties of the serieswhich may be obtained from the standard seriesby interchanging the signs of the terms in a quite arbitrary way.
Paramagnetic hysteresis
Authors: Temperley H. N. V. 
Published: November 2008

Ewing's original theory of hysteresis, though not admissible for metals, seems to apply to paramagnetic salts. The peculiar form of the interaction between dipoles implies that a certain fraction of them may be incapable of following small changes in the external field. The agreement with experiment is satisfactory, considering the rough nature of the theory.In conclusion, I should like to thank Messrs E. S. Shire and H. M. Barkla for kindly discussing their results with me before publication, and also Prof. R. H. Fowler, Dr J. D. Cockcroft and Mr A. H. Wilson for helpful discussions. Also I should like to thank the Provost and Fellows of King's College for the award of a studentship, during the tenure of which this work was carried out.
Configuration of Quadrivalent Atoms
Authors: Lowry T. M. 
Published: November 2008

Two alternative views have been expressed in regard to the configuration of quadrivalent atoms. On the one hand le Bel and van't Hoff assigned to quadrivalent carbon a tetrahedral configuration, which has since been confirmed by the X-ray analysis of the diamond. On the other hand, Werner in 1893 adopted an octahedral configuration for radicals of the type MA6, e.g. inand then suggested that “the molecules [MA4]X2 are incomplete molecules [MA6]X2. The radicals [MA4] result from the octahedrally-conceived radicals [MA6] by loss of two groups A, but with no function-change of the acid residue…. They behave as if the bivalent metallic atom in the centre of the octahedron could no longer bind all six of the groups A and lost two of them leaving behind the fragment [MA4]” (p. 303).
A study of the properties of hydrogen films on tungsten by the method of contact potentials
Authors: Bosworth R. C. L. 
Published: November 2008

In a study of the properties of hydrogen on tungsten by the method of contact potentials the following points have been established:(1) The contact potential of a 92% covered surface of hydrogen on tungsten against bare tungsten is 1·04 V., and the Richardson constants for such a surface are, approximately,A = 30, b = 5·60 V.(2) A film of deuterium is 20 m V. positive relative to a similar hydrogen film.(3) Over the range of temperatures and pressures used by Bryce in a study of the production of atomic hydrogen the films are nearly saturated, so that the production of atomic hydrogen is primarily due to a molecule striking a bare tungsten atom, one atom being adsorbed and the other going into the gas phase.(4)The condensation coefficient for hydrogen molecules on cold tungsten is 0·01.(5) The effective dipole moment of each hydrogen atom on the surface is −0·42 Debye unit and is independent of the fraction of the surface covered.
Note on an identity connected with diophantine approximation
Authors: Davenport H. 
Published: November 2008

In discussing Hecke's functionwhere {t} = t − [t] − ½ Hardy and Littlewood* made use of the identityHereθ is an irrational number between 0 and 1, and pν/qν is the νth convergent to θ (beginning with p0 = 0, q0 = 1). The proof of (1) given by Hardy and Littlewood is of an analytic character.
The Hankel transform of Whittaker's function Wk, m(z)
Authors: Erdélyi A. 
Published: November 2008

The Hankel transform of a function x−½νf(x) can be determined by the help of the following rule, obtained for ν = 0, 1 by B. van der Pol and K. Niessen(1), for positive integral values of ν by K. Niessen(2), and for arbitrary values of ν, [R(ν) > − 1], by F. Tricomi(3). If*F(p) ≒ f(x),then