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981.
Francesc Esteva Pere Garcia-Calvs Lluís Godo 《International Journal of Approximate Reasoning》1994,10(4):311-344
Two main semantical approaches to possibilistic reasoning with classical propositions have been proposed in the literature. Namely, Dubois-Prade's approach known as possibilistic logic, whose semantics is based on a preference ordering in the set of possible worlds, and Ruspini's approach that we redefine and call similarity logic, which relies on the notion of similarity or resemblance between worlds. In this article we put into relation both approaches, and it is shown that the monotonic fragment of possibilistic logic can be semantically embedded into similarity logic. Furthermore, to extend possibilistic reasoning to deal with fuzzy propositions, a semantical reasoning framework, called fuzzy truth-valued logic, is also introduced and proved to capture the semantics of both possibilistic and similarity logics. 相似文献
982.
Silvio Valentini 《Mathematical Logic Quarterly》1994,40(2):182-190
In this paper we prove that any quantale Q is (isomorphic to) a quantale of suitable relations on Q. As a consequence two isomorphism theorems are also shown with suitable sets of functions of Q into Q. These theorems are the mathematical background one needs in order to give natural and complete semantics for (non-commutative) Linear Logic using relations. Mathematics Subject Classification: 06D05, 06D10, 06D20, 03G25. 相似文献
983.
We analyze the Zeno's familiar paradox of the arrow using recently developed non-Boolean derived logics for classical systems. We show that the paradox depends upon a premise that is identically false in such logics, so that the language of experimental propositions is immune to the paradox. 相似文献
984.
在研究了MOSFET栅氧化层介质经时击穿物理机制的基础上,提出了氧化层击穿的逾渗模型.认为氧化层的击穿是E′心和氧空位等深能级缺陷产生与积累,并最终形成电导逾渗通路的结果.指出在电场作用下,氧化层中产生深能级缺陷,缺陷形成定域态,定域态的体积与外加电场有关.随着应力时间的增长,氧化层中的缺陷浓度增大,定域态之间的距离缩小.当定域态之间的距离缩小到一个阈值时,定域态之间通过相互交叠形成逾渗通路,形成扩展态能级,漏电流开始急剧增大,氧化层击穿.
关键词:
栅氧化层
TDDB
逾渗
模型 相似文献
985.
M. Léonetti 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,2(3):325-340
Two models are used in the literature, to study the electric behaviour of cellular membranes such as in protein aggregates,
excitable media or ionic currents for examples. The first one is the Electroneutral Model based on Nernst-Planck and Poisson
equations with a specific condition of microscopic electroneutrality. The second one is the Cable Model valid for long wavelengths
based on an analogy between an electric cable and a cell. Convincing experiments have justified the Cable equation. First,
we show that these two models are in contradiction. More precisely the assumption of electroneutrality is not considered in
the Cable Model. The main difference between the two models is highlighted by the analysis of the well known voltage instability
due to a negative differential conductance. Then, we derive a new semi-microscopic model (the Biomembrane Electrodiffusive
Model, called BEM) valid for phenomena at any wavelength. The BEM is based on Nernst-Planck and Poisson equations but, doesn't
imply microscopic electroneutrality. It reveals the capacitive behaviour of the membrane. In the limit of long wavelengths,
one recovers the behaviour described within the Cable framework, as shown precisely in the study of the negative differential
conductance analysis. Finally, we demonstrate the intimate link between the last models: the Cable Model appears as the limit
of the BEM for large wavelengths with some prerequisites which are discussed. The effects of geometry and asymmetrical media
are introduced.
Received: 8 November 1996 / Revised: 23 July 1997 and 8 December 1997 /
Accepted: 23 January 1998 相似文献
986.
A.A. Zvyagin D.M. Apal'kov 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,5(3):565-569
We present a Bethe Ansatz based investigation of a one-dimensional (1D) Heisenberg spin chain in a real 3D crystal lattice.
We have shown that due to an influence of the lattice distortion on a crystalline field of ligands of magnetic ions, a Heisenberg
antiferromagnetic spin chain is unstable under the appearance of a magnetic anisotropy of the “easy-plane” type. The effects of an external magnetic
field and nonzero temperature onto such a phase transition are studied.
Received: 19 January 1998 / Revised: 16 March 1998 / Accepted: 17 March 1998 相似文献
987.
Currently available approaches to molecular-scale logic gates are summarized and compared. These include: chemically-controlled fluorescent and transmittance-based switches concerned with small molecules, DNA oligonucleotides with fluorescence readout, oligonucleotide reactions with DNA-based catalysts, chemically-gated photochromics, reversibly denaturable proteins, molecular machines with optical and electronic signals, two-photon fluorophores and multichromophoric transient optical switches. The photochemical principles of electron and energy transfer are involved in several of these approaches. More complex molecular logic systems with reconfigurability and superposability provide contrasts with current semiconductor electronics. Integration of simple logic functions to produce more complex ones is also discussed in terms of recent developments. 相似文献
988.
Small metal clusters, like Au55(PPh3)12Cl6, which fall in the size regime of 1–2 nm are colloidal nanoparticles with quantum properties in the transitional range between metals and semiconductors. These chemically tailored quantum dots show regarding the Quantum Size Effect (QSE) a level splitting between 20 and 100 meV, increasing from small particle sizes to the molecular state. The organic ligand shell surrounding the cluster acts like a dielectric spacer generating capacitances between neighboring clusters down to 10–18 F. Therefore, charging effects superposed by level spacing effects can be observed. The ligand-stabilized colloidal quantum dots in condensed state can be described as a novel kind of artificial solid with extremely narrow mini or hopping bands depending on the chemically adjustable thickness of the ligand shell and its properties. Since its discovery, the Single Electron Tunneling (SET) effect has been recognized to be the fundamental concept for ultimate miniaturization in microelectronics. The controlled transport of charge carriers in arrangements of ligand-stabilized clusters has been observed already at room temperature through Impedance Spectroscopy (IS) and Scanning Tunneling Spectroscopy (STS). This reveals future directions with new concepts for the realization of simple devices for Single Electron Logic (SEL).
Part I presents the fundamental aspects of small ligand-stabilized metal clusters as well as their physical properties, emphasizing their electronic and optical properties with respect to dielectric response at ambient temperatures. 相似文献
989.
为解决化学审美教育空洞、肤浅、窄化的问题,提出"审美逻辑树"的思维工具。审美逻辑树包括美的产生(树干)、美的感受(一级分枝)、美的鉴赏(二级分枝)、美的延伸(三级或更高级分枝)等多条逻辑链(树枝)。三级分枝的内涵分别是:从实验现象中获得美感、分析美产生的原因、联想其他事物相近的美,核心分别是:外在形态、内在规律、普遍联系,层层递进。审美逻辑树以"美"为内在逻辑,因此可以跨越学科边界无限延伸,将实验现象、科学规律,甚至万事万物联系起来,促进化学与美学的联姻,甚至各学科各领域的大融合。 相似文献
990.