Extraordinarily high drive currents in asymmetrical double-gate MOSFETs

Numerical simulation results derived from a Schrödinger–Poisson tool applied to scaled double-gate (DG) MOSFETs, supplemented by analytical characterizations of the pertinent physics, are presented to give insight concerning the near-ideal features of DG devices and to explain how the low-voltage drive current of the asymmetrical DG MOSFET, having only one predominant channel, can be comparable to, and even higher than, that of the symmetrical-gate counterpart designed to have the same off-state current.     

Optimal Control for the Degenerate Elliptic Logistic Equation

We consider the optimal control of harvesting the diffusive degenerate elliptic logistic equation. Under certain assumptions, we prove the existence and uniqueness of an optimal control. Moreover, the optimality system and a characterization of the optimal control are also derived. The sub-supersolution method, the singular eigenvalue problem and differentiability with respect to the positive cone are the techniques used to obtain our results.     

Multiple positive solutions of periodic boundary value problems for second order impulsive differential equations

This paper is devoted to study the existence of multiple positive solutions for the second order periodic boundary value problem with impulse effects. The main results here are the generalization of Jiang [Daqing Jiang, On the existence of positive solutions to second order periodic BVPs, Acta Math. Sci. 18 (1998) 31–35] for ordinary differential equations. Existence is established via the theory of fixed point index in cones.     

Solvent and temperature effects on the conformational equilibria of a dihydrobenzo[h]quinolinium fluoroborate

Spectra of the N‐phenyl‐5,6‐dihydro‐2,4‐diphenylbenzo[h]quinolinium tetrafluoroborate (1) and of the N‐phenyl‐5,6,8,9‐tetrahydro‐7‐phenyldibenzo[c,h]acridinium tetrafluoroborate (2) were recorded in various solvents and temperatures. The analysis of the ¹H‐NMR spectra of the tetrafluoroborate salt 1, recorded in acetone, acetonitrile, 1,1,2,2‐tetrachloroethane and chloroform, revealed the existence of an equilibrium between two conformers in solution. Tight ion‐pairing in chloroform led to a smaller barrier for interconversion between the two conformers. In more polar solvents, where the dihydrobenzoquinolinium exists as a free cation, theoretical calculations predicted larger barriers. The spectra of 1 in 1,1,2,2‐tetrachloroethane also varied with temperature, resembling at higher temperatures the spectrum in CDCl₃ and at 300K spectra in more polar media. Spectra of 2 did not vary with the solvent or the temperature, in an indication of a much higher barrier to conformational interconversion, because of a greater steric hindrance between the N‐phenyl substituent and the dihydrobenzo rings. Copyright © 2009 John Wiley & Sons, Ltd.     

Approximating-topological methods in some problems of hydrodynamics

We describe a new approach to the study of initial-boundary value problems for evolutionary equations of hydrodynamics, which is based on approximation of the problems and subsequent application of topological degree theory for investigation of weak solvability for approximating problems. Use of this method turned out to be especially effective in problems of non- Newtonian hydrodynamics. We demonstrate its application to the study of weak solvability and attractors of the initial-boundary value problem for the Oldroyd model with regularized objective Jaumann derivative.     

Things That are Right with the Traditional Square of Opposition

The truth conditions that Aristotle attributes to the propositions making up the traditional square of opposition have as a consequence that a particular affirmative proposition such as ‘Some A is not B’ is true if there are no Bs. Although a different convention than the modern one, this assumption remained part of centuries of work in logic that was coherent and logically fruitful.      

Molecular distortion effect on ff-emission in a Pr(III) complex with 4,7-diphenyl-1,10-phenanthroline.

The electronic and structural behaviour of a Pr(III) complex with 4,7-diphenyl-1,10-phenanthroline, [Pr(bathophen)(2)(NO(3))(3)], is investigated with respect to the effect of configuration changes on the Pr(III) centre. [Pr(bathophen)(2)(NO(3))(3)] luminesces from the excited states of the ligand and the metal ion. The fluorescence, ff-emission ((1)D(2)-->(3)H(4)), and phosphorescence bands appear at 394, 608.2 and 482 nm, respectively, in the solid state. In acetonitrile, the complex also shows multiple emissions. From the time-resolved emission and the lifetime measurements, the excitation energy-transfer in [Pr(bathophen)(2)(NO(3))(3)] is clarified, that is, the upper excited triplet level of the ligand acts as an energy donor, while the (1)D(2) levels of Pr(III) is the acceptor. Additionally, the emission phenomena of the complex can be modified by molecular distortion, particularly by rotation of the phenyl groups in the ligand.     

Antifeedant effects of mixed methylphenyl hexaorganoditin compounds of the type PhnMe6–nSnSn on larvae of Spodoptera littoralis and Epilachna varivestis

Compounds of the series Ph_nMe_6–nSn₂ were prepared and tested for their antifeedant effects against Spodoptera littoralis (Boisduval) and Epilachna varivestis (Mulsant) larvae. In addition, phytotoxicity towards bean seedlings was measured. The most active compound against both Spodoptera and Epilachna was Ph₃Me₃Sn₂. The compound at 50 mg dm^?3 was comparatively innocuous in phytotoxicity tests against bean seedlings.