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111.
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The successive steps of the computer analysis of a NMR spectrum are examined. Better results can be obtained by direct simulation of tentative model spectra. As an example the 1H-NMR spectrum of amphetamine is analysed. 相似文献
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114.
Jin-Song Pei François Gay-Balmaz Joseph P. Wright Michael D. Todd Sami F. Masri 《Nonlinear dynamics》2017,88(4):2435-2455
We call attention to a dual-pair concept for modeling hysteresis involving instantaneous switching: Specifically, there are two input–output pairs for each hysteresis model under one specific input, namely a differential pair and an integral pair. Currently in engineering mechanics, only one pair is being recognized and utilized, not the other. Whereas this dual-pair concept is inherent in the differential and algebraic forms of memristors and memcapacitors, the concept has not been carried over to memristive system theory, nor to memcapacitive system theory. We show that the “zero-crossing” feature in memristors, memcapacitors, and memristive/memcapacitive models (i.e., the “mem-models”) is also a feature of the differential pairs of well-known non-mem-models, examples of which are Ramberg–Osgood, Bouc–Wen, bilinear hysteresis, and classical Preisach. The dual-pair concept thus connects mem-models and non-mem-models, thereby facilitating the modeling of hysteresis, and raising a set of scientific questions for further studies that might not otherwise come to awareness. 相似文献
115.
François Clautiaux Cláudio Alves José Valério de Carvalho 《Annals of Operations Research》2010,179(1):317-342
Dual-feasible functions are valuable tools that can be used to compute both lower bounds for different combinatorial problems
and valid inequalities for integer programs. Several families of functions have been used in the literature. Some of them
were defined explicitly, and others not. One of the main objectives of this paper is to survey these functions, and to state
results concerning their quality. We clearly identify dominant subsets of functions, i.e. those which may lead to better bounds or stronger cuts. We also describe different frameworks that can be used to create
dual-feasible functions. With these frameworks, one can get a dominant function based on other ones. Two new families of dual-feasible
functions obtained by applying these methods are proposed in this paper. 相似文献
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Simoens François Meilhan Jérôme Nicolas Jean-Alain 《Journal of Infrared, Millimeter and Terahertz Waves》2015,36(10):961-985
Journal of Infrared, Millimeter, and Terahertz Waves - Sensitive and large-format terahertz focal plane arrays (FPAs) integrated in compact and hand-held cameras that deliver real-time terahertz... 相似文献
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Crenguta Dordea Frédéric Brisach Jaouad Haddaoui Françoise Arnaud-Neu Michael Bolte Alessandro Casnati 《Supramolecular chemistry》2013,25(6):347-357
Calix[4]arene derivatives fixed in the 1,3-alternate conformation and substituted at one side by four carbamoylmethylphosphine oxide (CMPO) residues were synthesised. Two CMPO groups are directly attached to the wide rim, while the second pair is bound to the narrow rim via a tri- or tetramethylene spacer. Similar compounds, in which two CMPO groups at the wide rim are combined with two picolinamide groups or two ionisable carboxylic groups at the narrow rim, were also prepared. Some of these calixarene derivatives were studied as extractants for lanthanides (La3+, Eu3+, Yb3+) and thorium (Th4+) from acidic solution into methylene chloride. For selected samples, stability constants in methanol were determined by spectrophotometric titrations. Three compounds (1b′, 13, 17) in the 1,3-alternate conformation and one intermediate in the cone conformation (18) were confirmed by a crystal structure. 相似文献
120.
Dr. Sylvain Achelle Dr. Jean‐Pierre Malval Dr. Stéphane Aloïse Dr. Alberto Barsella Dr. Arnaud Spangenberg Dr. Loic Mager Dr. Huriye Akdas‐Kilig Dr. Jean‐Luc Fillaut Prof. Bertrand Caro Prof. Françoise Robin‐le Guen 《Chemphyschem》2013,14(12):2725-2736
The nonlinear properties and the photophysical behavior of two π‐conjugated chromophores that incorporate an electron‐deficient pyrimidine core (A) and γ‐methylenepyrans as terminal donor (D) groups have been thoroughly investigated. Both dipolar and quadrupolar branching strategies are explored and rationalized on the basis of the Frenkel exciton model. Even though a cooperative effect is clearly observed if the dimensionality is increased, the nonlinear optical (NLO) response of this series is moderate if one considers the nature of the D/A couple and the size of the chromophores (as measured by the number of π electrons). This effect was attributed to a disruption in the electronic conjugation within the dyes’ scaffold for which the geometry deviates from planarity owing to a noticeable twisting of the pyranylidene end‐groups. This latter structural parameter also has a strong influence on the excited‐state dynamics, which leads to a very efficient fluorescence quenching. 相似文献