Hybridization-induced wide-band bipolaron model for high-Tc superconductors

Abstract

A microscopic theory based on the idea of hybridization-induced wide-band bipolarons is proposed to explain the occurrence of high-temperature superconductors such as La_2?x-Ba_xCuO₄, and La_2?xSr_xCuO₄. In our view, these are such that bipolarons are formed whose singlet ground state possesses a large binding energy (Δ) with bandwidth W (>Δ) as a result of two distinct electron-phonon mechanisms and two types of hybridization between Cu²⁺ d electrons and other electrons. This wide-band bipolaron gas has features similar to Cooper pairs and leads to a superconducting state with high T_c in which all occupied electron states participate. The large electron-phonon coupling and a large W both cause the transition temperature T_c, to rise spectacularly.     

Adding Involution to Residuated Structures

Two constructions for adding an involution operator to residuated ordered monoids are investigated. One preserves integrality and the mingle axiom x ²x but fails to preserve the contraction property xx ². The other has the opposite preservation properties. Both constructions preserve commutativity as well as existent nonempty meets and joins and self-dual order properties. Used in conjunction with either construction, a result of R.T. Brady can be seen to show that the equational theory of commutative distributive residuated lattices (without involution) is decidable, settling a question implicitly posed by P. Jipsen and C. Tsinakis. The corresponding logical result is the (theorem-) decidability of the negation-free axioms and rules of the logic RW, formulated with fusion and the Ackermann constant t. This completes a result of S. Giambrone whose proof relied on the absence of t.     

Gleason's Theorem Has a Constructive Proof

Gleason's theorem for R ³ says that if f is a nonnegative function on the unit sphere with the property that f(x) + f(y) + f(z) is a fixed constant for each triple x,y,z of mutually orthogonal unit vectors, then f is a quadratic form. We examine the issues raised by discussions in this journal regarding the possibility of a constructive proof of Gleason"s theorem in light of the recent publication of such a proof.     

A note on the ω-incompleteness formalization

The paper studies two formal schemes related to -completeness.LetS be a suitable formal theory containing primitive recursive arithmetic and letT be a formal extension ofS. Denoted by (a), (b) and (c), respectively, are the following three propositions (where (x) is a formula with the only free variable x): (a) (for anyn) ( _T (n)), (b) _{T x} Pr _T (^–(x)^–) and (c) _T x(x) (the notational conventions are those of Smoryski [3]). The aim of this paper is to examine the meaning of the schemes which result from the formalizations, over the base theoryS, of the implications (b) (c) and (a) (b), where ranges over all formulae. The analysis yields two results overS : 1. the schema corresponding to (b) (c) is equivalent to ¬Cons _T and 2. the schema corresponding to (a) (b) is not consistent with 1-CON _T. The former result follows from a simple adaptation of the -incompleteness proof; the second is new and is based on a particular application of the diagonalization lemma.Presented byMelvin Fitting     

Psychosocial mediators of a theory-based resistance training maintenance intervention for prediabetic adults

Objective: Examine psychosocial mediators of the effects of high vs. low-dose resistance training (RT) maintenance interventions among older (ages 50–69), overweight and pre-diabetic adults.

Design: Participants (N = 123) completed a three-month supervised RT initiation phase and were subsequently randomised (time 1) to high or low-dose six-month unsupervised RT maintenance interventions (time 2), followed by a six-month no-contact phase (time 3).

Main Outcome Measures: Online measures of putative mediators and RT behaviour.

Results: RT intervention condition (high vs. low dose) had significant effects on change from time 1 to time 2 in behavioural expectation, self-regulation and perceived satisfaction (f² = .04–.08), but not outcome expectancies, RT strategies or behavioural intentions (f² ≤ .02). Change in each of the putative mediators, except for outcome expectancies (f² ≤ .02), had significant effects on RT behaviour at times 2 (f² = .12–.27) and 3 (f² = .23–.40). In a multiple mediation model, behavioural expectation (f² = .11) and self-regulation (f² = .06) mediated the effects of RT intervention condition on time 2 RT behaviour, whereas perceived satisfaction did not (f² = .01). Self-regulation was a significant mediator of intervention effects on time 3 RT behaviour (f² = .11), but behavioural expectation and perceived satisfaction were not (f² = .04).

Conclusions: Findings suggest that behavioural expectation and self-regulation are appropriate targets for RT maintenance interventions among at-risk older adults.     

Electron spin resonance of hydrogenated amorphous silicon-carbon alloy films prepared by magnetron sputtering

Abstract

New electron spin resonance (ESR) lines with g¹ = 2·0017 and g₂ and g₃ = 2·0006 have been found in the ESR spectra of as-deposited a-Si_1–x C_x:H films prepared by magnetron sputtering of silicon in the gas mixtures of methane and argon. Similarities between the observed spectra and those for the E′ centre in glassy SiO₂ are discussed.     

Book reviews

The I?varapratvabhijñākārikā of Utpaladeva with the Author's Vrtti. Critical edition and annotated translation. Serie Orientale Roma LXXI. Raffaele Toreha, 1994, Roma, Istituto Italiano per il Medio ed Estremo Oriente, LIV+ 273 pp., pb L. 110.000

Jung and Eastern Thought: a Dialogue with the Orient. John James Clarke, 1994, London, Routledge, vii +217 pp., £12.99

Abu Ya^cqub al‐Sijistani: Intellectual Missionary. Paul E. Walker, 1996, London, I. B. Tauris, xv + 132 pp.

Religious Pluralism and Truth: Essays on Cross‐cultural Philosophy of Religion. Edited by Thomas Dean, 1995, Albany, SUNY Press, xi + 271 pp., 0 7914 2123 6 hb, 0 7914 2124 4 pb, $19.95

The Body, Self‐cultivation, and Ki‐energy. Yuasa Yasuo, trans, by Shigenori Nagatomo and Monte S. Hull, 1993, Albany, SUNY Press, xxxvi + 229 pp. 814.95     

Book reviews

Time's Arrow and Archimedes’ Point: New Directions for the Physics of Time Huw PRICE, 1996 New York, Oxford University Press xiii + 306 pp. SCAN 37.00 (hardcover) ISBN 0–19–510095–6

Mental Reality GALEN STRAWSON, 1994 Cambridge, MA, The MIT Press xiv + 337 pp., S37.50 (cloth), $17.50 (paper) ISBN 0–262–19352–3 (paper)

The Rule of Reason: The Philosophy of Charles Sanders Peirce JACQUELINE BRUNNING & PAUL FORSTER, Eds, 1997 Toronto, University of Toronto Press 316 pp., $80.00 (hardcover), $24.95 (paperback) ISBN 0–8020–0829–1 (cloth), ISBN 0–8020–7819–2 (paper)

Scientific Knowledge: A Sociological Approach BARRY BARNES, DAVID BLOOR & JOHN HENRY, 1996 Chicago, University of Chicago Press xvi + 230 pp., ISBN 0–226–03730–4 (cloth), 0–226–03713–2 (paperback)

The Scientific Revolution STEVEN SHAPIN, 1996 Chicago, University of Chicago Press x + 218 pp., ISBN 0–226–75020–5 (cloth), 0–226–75021–3 (paperback)     

Book reviews

Nietzsche and Buddhism: a study in nihilism and ironic affinities. Robert G. Morrison, 1997, Oxford, Oxford University Press x + 250 pp., hb ISBN 0 19 823556 9, £32.50

Chong Yagyong: Korea's challenge to orthodox neo‐Confucianism. Mark Sftton, 1997, Albany, NY, State University of New York Press, >xv + 232 pp., pb ISBN 0 7914 3174 6, US$15.95

Fatalism in Ancient India. Sukumari Bhattacharji, 1995, Calcutta, Sarmistha Roy for Baulmon Prakashan xxviii + 356 pp., hb Rs250, ISBN 81 86552 02 2

The Vimalakirti Sutra (from the Chinese version by Kumarajiva). Burton Watson (Trans.), 1997, New York, Columbia University Press xii+ 168 pp., hb £18.00 ISBN 0 231 10656 4

Zhouyi, the Book of Changes‐a new translation with commentary. Richard Rutt, 1996, Richmond, Curzon Press xii + 498 pp., hb (Price not given), ISBN 0 70007 0467 1     

Illness representations predict adherence in adolescents and young adults with type 1 diabetes

Objective: Most adolescents and young adults (AYAs) with type 1 diabetes struggle with diabetes self-management and exhibit suboptimal glycemic control. This study examined two models of association between illness representations, a modifiable predictor of suboptimal outcomes, and adherence and glycemic control in AYAs with type 1 diabetes.

Design and main outcome measures: Ninety-nine AYAs (ages 15–20?years) completed measures of illness representations and adherence at two visits. Blood glucose monitoring frequency and haemoglobin A1c were obtained via chart review. Relationships were examined using structural equation modelling.

Results: Illness representations accounted for a significant proportion of the variance in blood glucose monitoring frequency (ΔR^2?=?.23, p?<?.01) and adherence to emergency precautions at Time 1 (ΔR^2?=?.07, p?=?.03). Illness representations also accounted for significant variance in blood glucose monitoring frequency (ΔR^2?=?.08, p?=?.01), adherence to recommendations for insulin and food (ΔR²?=?.08, p?=?.02) and exercise (ΔR^2?=?.10, p?<?.01), and adherence to emergency precautions (ΔR^2?=?.16, p?<?.01) at Time 2.

Conclusion: Illness representations are salient predictors of adherence in this population. Interventions targeting adherence promotion and glycemic control in AYAs with type 1 diabetes may be enhanced by efforts to modify illness representations.     

Stress-corrosion cracking in YBa2Cu3O7−x ceramic superconductor

Abstract

Thin-foil transmission electron microscopy specimens of orthorhombic YBa²Cu³O^7?x subjected to residual elastic strains have shown slow crack growth in an atmosphere with low moisture content. Microcracks, initiated by amorphization at the strained edges, propagate alternately along (110) twin boundaries and (001) stacking faults, where strain energy is accumulated locally. The formation of carbon-rich amorphous layers along the strained lattice planes, followed by residual stress-assisted crack propagation, resembles stress-corrosion cracking in this ceramic superconductor.     

Predictive probability and analogy by similarity in inductive logic

The-continuum of inductive methods was derived from an assumption, called-condition, which says that the probability of finding an individual having propertyx _j depends only on the number of observed individuals having propertyx _j and on the total number of observed individuals. So, according to that assumption, all individuals with properties which are different fromx _j have equal weight with respect to that probability and, in particular, it does not matter whether any individual was observed having some propertysimilar tox _j (the most complete proof of this result is presented in Carnap, 1980).The problem thus remained open to find some general condition, weaker than the-condition, which would allow for thederivation of probability functions which might be sensitive to similarity. Carnap himself suggested a weakening of the-condition which might allow for similarity sensitive probability functions (Carnap, 1980, p. 45) but he did not find the family of probability functions derivable from that principle. The aim of this paper is to present the family of probability functions derivable from Carnap's suggestion and to show how it is derived.In Section 1 the general problem of analogy by similarity in inductive logic is presented, Section 2 outlines the notation and the conceptual background involved in the proof, Section 3 gives the proof, Section 4 discusses Carnap's principle and the result, Section 5 is a brief review of the solutions which have previously been proposed.     

A semantical investigation into Leśniewski's axiom of his ontology

A structure A for the language L, which is the first-order language (without equality) whose only nonlogical symbol is the binary predicate symbol , is called a quasi -struoture iff (a) the universe A of A consists of sets and (b) a b is true in A ([p) a = {p } & p b] for every a and b in A, where a(b) is the name of a (b). A quasi -structure A is called an -structure iff (c) {p } A whenever p a A. Then a closed formula in L is derivable from Leniewski's axiom x, y[x y u (u x) u; v(u, v x u v) u(u x u y)] (from the axiom x, y(x y x x) x, y, z(x y z y x z)) iff is true in every -structure (in every quasi -structure).     

Book reviews

History of Islamic Philosophy Seyyed Hossein Nasr & Oliver Leaman, Editors, 1996 London, Routledge Part I, xx+ 780 pp., Part II, xiv + 428 pp., hb ISBN 0415 05 6675, £120.00

Early Advaita Vedānta and Buddhism: the Mahāyāna context of the Gaudapādiya‐Kārikā Richard King, 1995 Albany, State University of New York Press xii + 341 pp., pb $19.95

Vaisnavism: its philosophy, theology and religious discipline S.M. Srinwasa Chari, 1994 Delhi, Motilal Banarsidass xxxviii + 383 pp., pb Rs. 350

Vaisnavism: contemporary scholars discuss the Gaudiya tradition Steven J. Rosen (Ed.), 1992 Delhi, Motilal Banarsidass, 1994 ix + 354 pp., pb Rs. 160

Cultural Realism: strategic culture and grand strategy in Chinese history Alastair Iain Johnston, 1995 Princeton, Princeton University Press xiii + 367 pp., hb ISBN 0691029962, $39.50

Laughing at the Tao: debates among Buddhists and Taoists in medieval China Livia Kohn, 1995 Princeton, Princeton University Press xii + 281 pp. hb (price not given)

Pantheism. A Non‐theistic Concept of Deity Michael P. Levine, 1994 London, Routledge xii + 388 pp., hb £45 ISBN 0415070643     

Investigating the Performance of Alternate Regression Weights by Studying All Possible Criteria in Regression Models with a Fixed Set of Predictors

We describe methods for assessing all possible criteria (i.e., dependent variables) and subsets of criteria for regression models with a fixed set of predictors, x (where x is an n×1 vector of independent variables). Our methods build upon the geometry of regression coefficients (hereafter called regression weights) in n-dimensional space. For a full-rank predictor correlation matrix, R _xx, of order n, and for regression models with constant R ² (coefficient of determination), the OLS weight vectors for all possible criteria terminate on the surface of an n-dimensional ellipsoid. The population performance of alternate regression weights—such as equal weights, correlation weights, or rounded weights—can be modeled as a function of the Cartesian coordinates of the ellipsoid. These geometrical notions can be easily extended to assess the sampling performance of alternate regression weights in models with either fixed or random predictors and for models with any value of R ². To illustrate these ideas, we describe algorithms and R (R Development Core Team, 2009) code for: (1) generating points that are uniformly distributed on the surface of an n-dimensional ellipsoid, (2) populating the set of regression (weight) vectors that define an elliptical arc in ℝ ⁿ , and (3) populating the set of regression vectors that have constant cosine with a target vector in ℝ ⁿ . Each algorithm is illustrated with real data. The examples demonstrate the usefulness of studying all possible criteria when evaluating alternate regression weights in regression models with a fixed set of predictors.     

Book Reviews

The Economics of Science: Methodology and Epistemology as if Economics Really Mattered. James R. Wible, 1998. London and New York, Routledge. xviii + 266 pp., US$75.00, £45.00. ISBN 0–415–17257–8

The Dawning of Gauge Theory. Lochlainn O'Raifeartaigh, 1997. Princeton, NJ, Princeton University Press. ix + 249 pp., $US 69.50 (hardback), $US 29.95 (paperback). ISBN 0–691–02978–4 (hardback), 0–691–02977–6 (paperback)

Mathematics as a Science of Patterns. Michael D. Resnik, 1997. Oxford, Clarendon Press. ISBN 0–19–823608–5

Proof Theory and Automated Deduction. Jean Goubault‐Larrecq & Ian Mackie, 1997. Dordrecht, Kluwer. xv+ 425 pp., $US 155, £96. ISBN 0–7923–4593–2 (hardback)     

Microwave-dielectric and magnetic properties of Ta-doped BiFeO3 nanopowders

BiFe_{1? x} Ta _x O₃ (x = 0, 0.05, 0.1) nanopowders have been fabricated by a simple sol–gel method. Dielectric measurements at microwave frequencies (2–18 GHz) were made using a vector network analyser. Without tantalum, the BiFeO₃ nanopowder presents a relaxation-like response with a characteristic frequency of 15 GHz, which can be associated with an overdamped process. The Ta-doped nanopowders, however, show resonant behaviour with resonant frequencies of 12.5 and 14.6 GHz. The intensity of the resonant peak near 14.6 GHz decreases with increasing Ta addition. This behaviour is associated with a damped resonance process. Room-temperature magnetic measurements indicate that the addition of Ta influences the magnetic properties of the BiFeO₃ nanopowders, with BiFe_0.95Ta_0.05O₃ having the strongest ferromagnetism with a saturation magnetisation M _s of about 0.05 µ_B/Fe. The origin of the enhanced ferromagnetism is possibly associated with the distortion of the oxygen octahedral by the Ta substitution or/and the statistical distribution of Fe³⁺ and Fe²⁺.     

Book reviews

Thirty‐Five Oriental Philosophers. Diane Collinson & Robert Wilkinson, 1994, London and New York, Routledge, vi + 205 pp., £35

Essays on Indian Philosophy Traditional and Modern. J. N. Mohanty (edited by Purushottama Bilimoria), 1993, Delhi, Oxford University Press, xxxvii + 347 pp., Rs. 500

Gates of Light (Sha'are Orah). Rabbi Joseph Gikatilla, 1994, London, Harper Collins, 400 + xxxiv pp., $30