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161.
Daniele Ielmini 《Microelectronic Engineering》2009,86(7-9):1870-1875
Flash memory, in particular NAND, has been an enabling technology for portable applications for the last two decades. The strength of Flash is its excellent scaling capability, allowing an ever increasing density at a decreasing cost and maintained reliability. However, the geometrical scaling of the cell exacerbates charge loss and fluctuation effects. On the other hand, new post-Flash memory technologies are being proposed, with different storage concepts and reliability physics. This review discusses the major reliability issues for Flash, with emphasis on the physical mechanisms and modeling. The reliability of charge trap and resistive memories, such as phase change and resistive switching memories, is addressed. 相似文献
162.
163.
Sergio Scognamillo Valeria Alzari Daniele Nuvoli Alberto Mariani 《Journal of polymer science. Part A, Polymer chemistry》2010,48(11):2486-2490
Frontal polymerization was used as an alternative technique for the preparation of super water absorbent hydrogels obtained from acrylamide and 3‐sulfopropyl acrylate, potassium salt (SPAK) in the presence of N,N′‐methylene‐bisacrylamide as a crosslinker. All samples were synthesized in dimethyl sulfoxide, and their swelling behavior in water was investigated. It was found that their features are dependent on the monomer ratio used, which influenced the porous morphology, and consequently, the swelling capability. The swelling ratio ranges from about 1000% for the acrylamide homopolymer up to 14,000% for the sample containing 87.5 mol % of SPAK, thus indicating that this parameter can be easily tuned by using the appropriate monomer ratio. The affinity towards water was eventually confirmed by contact angle analysis. Polymer hydrogels made from at least 62.5 mol % SPAK exhibit a thermoresponsive behavior, with a lower critical solution temperature of ~30 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2486–2490, 2010 相似文献
164.
165.
The continuum as a formal space 总被引:1,自引:0,他引:1
A constructive definition of the continuum based on formal topology is given and its basic properties studied. A natural
notion of Cauchy sequence is introduced and Cauchy completeness is proved. Other results include elementary proofs of the
Baire and Cantor theorems. From a classical standpoint, formal reals are seen to be equivalent to the usual reals. Lastly,
the relation of real numbers as a formal space to other approaches to constructive real numbers is determined.
Received: 11 November 1996 相似文献
166.
Summary. Two new augmented Lagrangian formulations for mixed finite element schemes are presented. The methods lead, in some cases,
to an improvement in the order of the approximation. An error analysis is provided, together with some interesting examples
of applications.
Received July 27, 1994 / Revised version received November 17, 1995 相似文献
167.
168.
Daniele Fournier-Prunaret 《Circuits, Systems, and Signal Processing》2005,24(5):615-638
This paper deals with a differential pulse code modulation (DPCM) transmission
system. It includes an encoder which uses a coupling between a transversal predictor and a
nonlinear quantizer. This paper studies, from a dynamical point of view, an order 2 DPCM
system modeled via a noninvertible two-dimensional map. Chaotic phenomena can be
observed; depending on the kind of application, it can be interesting to avoid chaos or
to use it. In both cases, it is necessary to understand the mechanisms which give rise to it.
For that, the usual tools of chaotic dynamics are used (bifurcation structures, critical and
invariant manifolds). 相似文献
169.
Vector displacements expressed in spherical coordinates are proposed. They correspond to electromagnetic fields in vacuum that globally rotate about an axis and display many circular patterns on the surface of a ball. The fields satisfy the set of Maxwell's equations, and some connections with magnetohydrodynamics can also be established. The solutions are extended with continuity outside the ball. In order to avoid peripheral velocities of arbitrary magnitude, as it may happen for a rigid rotating body, they are organized to form successive encapsulated shells, with substructures recalling ball-bearing assemblies. A recipe for the construction of these solutions is provided by playing with the eigenfunctions of the vector Laplace operator. Some applications relative to astronomy are finally discussed. 相似文献
170.
Inside Cover: Benzoxazolone Carboxamides: Potent and Systemically Active Inhibitors of Intracellular Acid Ceramidase (Angew. Chem. Int. Ed. 2/2015)
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