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151.
The effect of a nonspherical particle shape and shape polydispersity on the structure of densely packed hard colloidal particles was studied in real space by confocal microscopy. We show that the first layer at the wall of concentrated size-monodisperse but shape-polydisperse polyhedral colloids exhibits significant deviations from a hexagonal lattice. These deviations are identified as bond-orientational fluctuations which lead to percolating "mismatch lines." While the shape-induced geometrical frustration of the hexagonal symmetry suppresses translational order, bond-orientational order is clearly retained, indicating a hexaticlike structure of the polyhedral colloids. 相似文献
152.
The Ramanujan Journal - We introduce holomorphic Hermite polynomials in n complex variables that generalize the Hermite polynomials in n real variables introduced by Hermite in the late 19th... 相似文献
153.
We study the sparsest cut problem when the “capacity-demand” graph is planar, and give a combinatorial polynomial algorithm. In this type of graphs there is an edge for each positive capacity and also an edge for each positive demand. We extend this result to graphs with no \(K_5\) minor. We also show how to find a maximum concurrent flow in these two cases. We also prove that the sparsest cut problem is NP-hard if we only impose that the “capacity-demand” graph has no \(K_6\) minor. We use ideas that had been developed for the max-cut problem, and show how to exploit the connections among these problems. 相似文献
154.
We consider a linear system of Timoshenko type in a bounded interval. No dissipative mechanism is added in the system or at
the edges of the beam. The damping occurs through a thermal effect by coupling the system with a heat equation suggested by
Green and Naghdi. We prove exponential decay of solutions of the augmented system. 相似文献
155.
Egan T. Mourad S. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2005,13(8):984-988
This paper introduces a new approach to testing a basic analog-only delay-locked loop (DLL) that is embedded in a field-programmable gate array, an application specific integrated circuit, or a system-on-chip (SoC). Part of the DLL circuitry is duplicated and then connected to the DLL in a way that produces a replica of the control voltage. This shadow of the control voltage is used to measure the loop's response to a step in phase. The concept of test construct (TC) gain is introduced as a means of improving detectability. The benefit of the testing approach is demonstrated by injecting defects into the DLL and detecting them through the TC at the observation point. 相似文献
156.
Andras Gaspar Mourad Harir Norbert Hertkorn Philippe Schmitt‐Kopplin 《Electrophoresis》2010,31(12):2070-2079
Free‐flow electrophoresis (FFE), a preparative free zone electrophoretic method, was used offline in conjunction with ultrahigh‐resolution FT/ion cyclotron resonance ‐MS to resolve the complexity of Suwannee River fulvic acid (SRFA). Before MS, the FFE separation conditions and the compatibility with ESI were optimized. The constituents in SRFA were effectively separated based on their charge states and sizes. The obtained mass spectra were compared by means of van Krevelen diagrams and the calculated aromaticity indices of the individual constituents were used to describe the distribution of aromatic/unsaturated structures across the FFE‐fractionated samples. The consolidated number of ions observed within the individual SRFA fractions were much higher than those of the bulk samples alone, demonstrating extensive ion suppression effects in bulk SRFA likely also operating in the analysis of complex biogeochemical mixtures in flow injection mode. The FFE approach allows for producing sizable amounts of sample from dilute solutions, which can be easily fractionated into dozens of individual samples with the possibility of further in‐depth characterization. 相似文献
157.
Litvin M.E. Mourad S. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2005,13(4):462-475
A new family of self-reset logic (SRL) cells is presented in this paper. The single-ended basic structure proposed realizes an incomplete logic family, since it is incapable of inverting logic. Thus, a dual-rail SRL (DRSRL) implementation is also proposed. These cells maintain small delay variations for all input combinations, once minimum timing requirements on inputs are satisfied, and produce output pulses of fairly constant width for varying fanout, leaving enough headroom in the design to accommodate process, supply voltage, and temperature variations. These properties simplify the implementation of data-path and control circuits where the logic depth does not affect the stage output pulse width, eliminating the need for pulse-width controlling circuits required in previous works on SRL. In SRL, power is consumed only if new data are pumped through the logic. The clock grid is limited to the registers that launch and receive the signal path. The clocking overhead is thus reduced, compared with other dynamic designs, and it is especially suitable for wave pipelining. Case study examples and simulated characterization data are included to show the design methodology. 相似文献
158.
Mourad E. Ismail Ahmed I. Zayed 《Proceedings of the American Mathematical Society》2003,131(12):3711-3719
The Whittaker-Shannon-Kotel'nikov (WSK) sampling theorem plays an important role not only in harmonic analysis and approximation theory, but also in communication engineering since it enables engineers to reconstruct analog signals from their samples at a discrete set of data points. The main aim of this paper is to derive a -analogue of the Whittaker-Shannon-Kotel'nikov sampling theorem. The proof uses recent results in the theory of -orthogonal polynomials and basic hypergeometric functions, in particular, new results on the addition theorems for -exponential functions.
159.
The title compound, isolated from leaves, is a new alkyl-3-phthalide characterized by an acylated side chain. It has been identified by spectral analysis as [3-(1-β-D-glucosyloxy)-2-hydroxy]benzoyl 3-(3-phthalidyl)-propyl ester. 相似文献
160.
Mourad Hidouri Besma Lajmi Mongi Ben Amara 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(11):i147-i148
Crystals of sodium zinc diiron(III) triphosphate, NaZnFe2(PO4)3, have been synthesized and structurally characterized by single‐crystal X‐ray diffraction. The compound features a new structural type built up from ZnO6 octahedra, FeO6 octahedra and FeO4 tetrahedra, linked together via the corners and edges of PO4 tetrahedra to form a three‐dimensional framework, with tunnels running along [100]. Within these tunnels, Na+ cations occupy a highly distorted cubic site. 相似文献