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111.
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113.
Gaber El-Enany Matthew J. Lacey Phil A. Johns John R. Owen 《Electrochemistry communications》2009,11(12):2320-2323
Polyacrylonitrile (PAN) films were grown on glassy carbon, nickel foam and MnO2 substrates by cathodic electropolymerisation of acrylonitrile in acetonitrile with tetrabutylammonium perchlorate (TBAP) as the supporting electrolyte. The electronic barrier properties of the films were confirmed by impedance spectroscopy of carbon |PAN| Hg cells while the ionic resistance of the films varied from 200 kΩ cm2 in the dry state to 1.4 Ω cm2 when plasticised with 1 M LiPF6 in propylene carbonate. A galvanic cell was prepared by successive electrodepositions of MnO2 and PAN on a carbon substrate, using liquid lithium amalgam as the top contact. The cell showed a stable open circuit potential and behaved normally under the galvanostatic intermittent titration technique (GITT). 相似文献
114.
James Owen Weatherall 《Foundations of Physics》2012,42(2):209-214
The status of the geodesic principle in General Relativity has been a topic of some interest in the recent literature on the
foundations of spacetime theories. Part of this discussion has focused on the role that a certain energy condition plays in
the proof of a theorem due to Bob Geroch and Pong-Soo Jang [“Motion of a Body in General Relativity.” Journal of Mathematical Physics
16(1) (1975)] that can be taken to make precise the claim that the geodesic principle is a theorem, rather than a postulate, of General
Relativity. In this brief note, I show, by explicit counterexample, that not only is a weaker energy condition than the one
Geroch and Jang state insufficient to prove the theorem, but in fact a condition still stronger than the one that they assume
is necessary. 相似文献
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116.
This research supports recent efforts to provide an energetic approach to the prediction of stress–strain relations for single crystals undergoing single slip and to give precise formulations of experimentally observed connections between hardening of single crystals and separation of active slip-bands. Non–classical, structured deformations in the form of two-level shears permit the formulation of new measures of the active slip-band separation and of the number of lattice cells traversed during slip. A formula is obtained for the Helmholtz free energy per unit volume as a function of the shear without slip, the shear due to slip, and the relative separation of active slip-bands in a single crystal. This formula is the basis for a model, under preparation by the authors, of hardening of single crystals in single slip that is consistent with the Portevin-Le Chatelier effect and the existence of a critical resolved shear stress. 相似文献
117.
In this paper we develop a cutting plane algorithm for solving mixed-integer linear programs with general-integer variables.
A novel feature of the algorithm is that it generates inequalities at all γ-optimal vertices of the LP-relaxation at each
iteration. The cutting planes generated in the procedure are found by considering a natural generalization of the 0-1 disjunction
used by Balas, Ceria, and Cornuéjols in the context of solving binary mixed-integer linear programs [3, 4].
Received: January 1999 / Accepted: March 2000?Published online December 15, 2000 相似文献
118.
James Owen Weatherall 《Foundations of Physics》2013,43(9):1153-1169
I present what might seem to be a local, deterministic model of the EPR-Bohm experiment, inspired by recent work by Joy Christian, that appears at first blush to be in tension with Bell-type theorems. I argue that the model ultimately fails to do what a hidden variable theory needs to do, but that it is interesting nonetheless because the way it fails helps clarify the scope and generality of Bell-type theorems. I formulate and prove a minor proposition that makes explicit how Bell-type theorems rule out models of the sort I describe here. 相似文献
119.
C.R. Leonardi D.R.J. Owen Y.T. Feng 《ournal of non Newtonian Fluid Mechanics》2011,166(12-13):628-638
In the present study, the flow of bulk materials is characterised as a non-Newtonian fluid and modelled using the lattice Boltzmann method. A power law and a Bingham model is implemented in the LBM, which is hydrodynamically coupled to the discrete element method (DEM) for structural interaction. The performance of both non-Newtonian models is assessed, both qualitatively and quantitatively, in benchmark problems. The validated, non-Newtonian LBM–DEM framework is then applied to the geometry of a cylindrical Couette rheometer to numerically determine the constitutive response of a sample of Leighton Buzzard sand. The numerical results, which employ the power law, are compared with experimental data, and a number of other synthetic soil samples are defined using the presented process of numerical rheometry. Finally, the numerical stress–strain rate response of the synthetic soil samples is interpreted within the context of a regularised Bingham model, and the similarities discussed. 相似文献
120.
Summerscales OT Cloke FG Hitchcock PB Green JC Hazari N 《Journal of the American Chemical Society》2006,128(30):9602-9603
The U(III) mixed-sandwich compound [U(eta-C5Me4H)(eta-C8H6{SiiPr3-1,4}2)(THF)] 1 may be prepared by sequential reaction of UI3 with K[C5Me4H] in THF followed by K2[C8H6{SiiPr3-1,4}2]. 1 reacts with carbon monoxide at -30 degrees C and 1 bar pressure in toluene solution to afford the crystallographically characterized dimer [(U(eta-C8H6{SiiPr3-1,4}2)(eta-C5Me4H)]2(mu-eta2: eta2-C4O4) 2, which contains a bridging squarate unit derived from reductive cyclotetramerization of CO. DFT computational studies indicate that addition of a 4th molecule of CO to the model deltate complex [U(eta-COT)(eta-Cp)]2(mu-eta1: eta2-C3O3)] to form the squarate complex [U(eta-COT)(eta-Cp)]2(mu-eta2: eta2-C4O4)] is exothermic by 136 kJ mol-1. 相似文献