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81.
We study light propagation in nanoscale periodic structures composed of dielectric and metal in the visible range. We demonstrate that diffraction curves of nonuniform waveguide arrays can be tailored by varying the geometric and dielectric features of the waveguides. The results obtained from a proper formulation of coupled mode theory for nonuniform arrays are validated through numerical solution of Maxwell equations in frequency domain. 相似文献
82.
We study the efficiency at maximum power, η*, of engines performing finite-time Carnot cycles between a hot and a cold reservoir at temperatures Th and Tc, respectively. For engines reaching Carnot efficiency ηC=1-Tc/Th in the reversible limit (long cycle time, zero dissipation), we find in the limit of low dissipation that η* is bounded from above by ηC/(2-ηC) and from below by ηC/2. These bounds are reached when the ratio of the dissipation during the cold and hot isothermal phases tend, respectively, to zero or infinity. For symmetric dissipation (ratio one) the Curzon-Ahlborn efficiency ηCA=1-√Tc/Th] is recovered. 相似文献
83.
Shapour Heidarkhani Massimiliano Ferrara Giuseppe Caristi Amjad Salari 《Acta Appl Math》2018,156(1):133-157
This article is concerned with the multiplicity results of the solutions for a Kirchhoff-type three-point boundary value problem. The method observed here is according to variational methods and critical point theory. In fact, through a consequence of the local minimum theorem due Bonanno and mountain pass theorem, we look into the existence results for our problem under algebraic conditions with the classical Ambrosetti-Rabinowitz (AR) condition on the nonlinear term. Furthermore, by combining two algebraic conditions on the nonlinear term, employing two consequences of the local minimum theorem due Bonanno we guarantee the existence of two solutions, and applying the mountain pass theorem given by Pucci and Serrin we establish the existence of third solution for the problem. 相似文献
84.
Sacchi MF 《Physical review letters》2006,96(22):220502
We derive the amount of information retrieved by a quantum measurement in estimating an unknown maximally entangled state, along with the pertaining disturbance on the state itself. The optimal tradeoff between information and disturbance is obtained, and a corresponding optimal measurement is provided. 相似文献
85.
Massimiliano Vignolo 《Metaphysica》2010,11(1):1-16
We speak of products in two senses: in one, we speak of types of products, in the other we speak of the particular objects that are instances of those types. I argue that types of products have the same ontological status as that of material stuffs, like water and gold, which have a non-particular level of existence. I also argue that the relationship between types of products and their instances is logically similar to the relation of constitution, which holds between, say, gold and a ring made of gold. In my approach, types of products are concrete entities, having spatiotemporal properties. This picture fits our commonplace conception of types of products better than alternative approaches according to which types of products are universal, abstract, or mereological entities. 相似文献
86.
In a letter to Born, Einstein wrote [42]: “Quantum mechanics is certainly imposing. But an inner voice tells me that it is not yet the real thing. The theory says a lot, but does not really bring us any closer to the secret of the ‘old one.’ I, at any rate, am convinced that He does not throw dice.” In this paper we take seriously Einstein’s famous metaphor, and show that we can gain considerable insight into quantum mechanics by doing something as simple as rolling dice. More precisely, we show how to perform measurements on a single die, to create typical quantum interference effects, and how to connect (entangle) two identical dice, to maximally violate Bell’s inequality. 相似文献
87.
88.
Hashempour Mazdak Vicenzo Antonello Bahdanchyk Maksim Bestetti Massimiliano 《Journal of Solid State Electrochemistry》2018,22(12):3895-3911
Journal of Solid State Electrochemistry - The interplay and overlapping of several factors determine the capacitive behavior of carbon composite electrodes for capacitive energy storage... 相似文献
89.
Cubic ordered mesoporous Co(3)O(4), prepared via the nanocasting pathway using KIT-6 as hard template, was found to be an excellent catalyst for low temperature CO oxidation, with the activity clearly depending on surface area and pore systems of the catalysts. 相似文献
90.
Here we report that at room temperature in acetonitrile after the reduction of the naphthalimide-site, a synthetic molecular thread undergoes a complete conformational change which makes possible an efficient conversion of chemical energy into mechanical work; such results point out the ability of the thread to act as a molecular device under electrochemical control. 相似文献