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121.
首先引入h型Stepanov 加权伪概自守函数和∞型Stepanov加权伪概自守函数的概念, 接着建立了其函数空间的完备性以及相应组合定理, 最后证明了一类非自治无穷时滞偏中立型泛函微分方程在Sp-加权伪概自守系数下加权伪概自守解的存在唯一性. 相似文献
122.
Gaston H. Gonnet 《BIT Numerical Mathematics》1977,17(2):170-183
Zero finders written in FORTRAN usually impose a false and inconvenient structure on the program. Desirable software and numerical features of a zero finder are discussed. A zero finder with a new structure is presented together with a number of examples that illustrate its flexibility.This work was supported by the Department of Communications, National Research Council and Defense Research Board of the government of Canada and by the University of Waterloo. 相似文献
123.
Gaston Casanova 《Advances in Applied Clifford Algebras》2005,15(1):151-155
All the letters represent relative integers, except
and
and i = e1e2 in R(2, 0) oder e1 in R(1, 0).
We study the Fermat’s equation
a, b, c being prime two and two and by utilizing an elementary method. We use the Gauss’ formula
where n = 5, 7, 11, 17.
相似文献
(1) |
1. |
If 2 is the p · g · c · d· of A and B we put
|
||
2. |
If βn = bn / (c − a) is not divisible by n, we write the expansion
|
||
3. | If one a, b oder c is divisible by n we prove the impossibility | ||
4. | In the case n = 3 the ring {a + bj} is euclidian which permits to conclude in favour of the impossibility. |
124.
Jin Liang Gaston M. N’Guérékata Ti-Jun Xiao Jun Zhang 《Nonlinear Analysis: Theory, Methods & Applications》2009
This paper is concerned with some properties of pseudo-almost automorphic functions, which are more general and complicated than pseudo-almost periodic functions. Using these properties, we establish an existence and uniqueness theorem for pseudo-almost automorphic mild solutions to semilinear differential equations in a Banach space. 相似文献
125.
Modeling has often failed to meet expectations, mostly because of the difficulty of comprehending relationships within phenomena and expressing them in mathematical models. Reality is frequently too complex to be reflected in a single model. This is often the case of marketing research, where variables relating to socioeconomics or psychographics constitute potential sources of heterogeneity. In such cases, the assumption of ‘one model fits all’ is unrealistic and may lead to inaccurate decisions. Thus, heterogeneity is a major issue in modeling. Once a model has been fitted to a complete data set that fulfills all validation criteria, it is difficult to establish whether it is valid for the whole population or it is merely an average artifact from several sub‐populations. The purpose of this paper is to present the Pathmox approach to deal with heterogeneity in partial least squares path modeling. The idea behind Pathmox is to build a tree of path models that have look‐alike structure as a binary decision tree, with different models for each of its nodes. The split criterion consists of an F statistic comparing two structural models. In order to ensure the suitability of the split criterion, a simulation study was conducted. Finally, we have applied Pathmox to a survey that measured Satisfaction among Spanish mobile phone operators. Results suggest that the Pathmox approach performs adequately in detecting partial least squares path modeling heterogeneity. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
126.
Paramonov S Fedorov Y Lokshin V Tulyakova E Vermeersch G Delbaere S Fedorova O 《Organic & biomolecular chemistry》2012,10(3):671-682
In this work, the interaction of protonated amino acids with a chromene bearing a fused 18-crown-6 ether moiety was studied by UV-vis and NMR spectroscopy. Initial closed forms of the chromene form monotopic 1 : 1 complexes, the ammonium group being localized inside the crown ether cavity. UV-irradiation leads to transformation of the ring-closed species into the ring-opened form. Depending on the amino acid length, either ditopic or monotopic 1 : 1 complexes are formed. Such complexes are stabilized by the additional H-bonding between the carboxylic group of the acid and the carbonyl oxygen atom of the ring-opened form. Cessation of the irradiation results in ring-closure to the chromene with concomitant change of the complexation mode. 相似文献
127.
SD Bergman TE Storr H Prokopcová K Aelvoet G Diels L Meerpoel BU Maes 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(33):10393-10398
A general directed Ru-catalyzed C(sp(3) )?H α-alkylation protocol for piperidines (less-reactive substrates than the corresponding five-membered cyclic amines) has been developed. The use of a hindered alcohol (2,4-dimethyl-3-pentanol) as the solvent and catalyst activator, and a catalytic amount of trans-1,2-cyclohexanedicarboxylic acid is necessary to achieve a high conversion to product. This protocol was used to effectively synthesize a number of 2-hexyl- and 2,6-dihexyl piperidines, as well as the alkaloid (±)-solenopsin?A. Kinetic studies have revealed that the carboxylic acid additive has a significant effect on catalyst initiation, catalyst longevity, and reverses the reaction selectivity compared with the acid-free reaction (promotes alkylation versus competing alkene reduction). 相似文献
128.
Hilkhuysen G Gaubitch N Brookes M Huckvale M 《The Journal of the Acoustical Society of America》2012,131(1):531-539
The effects on speech intelligibility of three different noise reduction algorithms (spectral subtraction, minimal mean squared error spectral estimation, and subspace analysis) were evaluated in two types of noise (car and babble) over a 12 dB range of signal-to-noise ratios (SNRs). Results from these listening experiments showed that most algorithms deteriorated intelligibility scores. Modeling of the results with a logit-shaped psychometric function showed that the degradation in intelligibility scores was largely congruent with a constant shift in SNR, although some additional degradation was observed at two SNRs, suggesting a limited interaction between the effects of noise suppression and SNR. 相似文献
129.
Sergey Paramonov Stéphanie Delbaere Olga Fedorova Yuri Fedorov Vladimir Lokshin André Samat Gaston Vermeersch 《Journal of photochemistry and photobiology. A, Chemistry》2010,209(2-3):111-120
Complexation between a benzopyran entity annulated with a 15-crown-5 ether unit and three metal cations, Mg2+, Ba2+, and Pb2+ has been investigated by UV–vis and NMR spectroscopy. The complexes composition, the stability constants and the structural arrangements have been determined. The photochemical and thermal properties of the photochromic benzopyran derivative in absence and in the presence of metals have been studied. The metal-ion-binding ability of the fused macrocyclic entity drastically modifies photochromism by decreasing the thermal stability of photomerocyanines, whereas the metal cations are partially ejected from crown-ether cavity when benzopyran is in open configuration. 相似文献
130.
Michel Julliard Chhan Siv Gaston Vernin Jacques Metzger 《Helvetica chimica acta》1978,61(8):2941-2948
Photochemical synthesis of biaryls and heterobiaryls from aryl and heteroarylamines, alkylnitrite and aromatic or heteromatic substrates The photochemical reaction of aromatic and heteroaromatic amines with excess t-butyl nitrite in aromatic solvents (benzene, p-xylene, mesitylene) and in hetero-aromatic solvents (furan, thiophene) leads to biaryls or heterobiaryls. t-Butyl nitrite is more convenient than isopentyl nitrite which gives by-products. This new method has been used to synthesize 28 compounds in 17 to 60% yield. 相似文献