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111.
A.L. Cherchiglia A.R. Vieira Brigitte Hiller A.P. Baêta Scarpelli Marcos Sampaio 《Annals of Physics》2014
In this contribution, we present a new perspective on the control of quadratic divergences in quantum field theory, in general, and in the Higgs naturalness problem, in particular. Our discussion is essentially based on an approach where UV divergences are parameterized, after being reduced to basic divergent integrals (BDI) in one internal momentum, as functions of a cutoff and a renormalization group scale λ. We illustrate our proposal with well-known examples, such as the gluon vacuum self energy of QCD and the Higgs decay in two photons within this approach. We also discuss frameworks in effective low-energy QCD models, where quadratic divergences are indeed fundamental. 相似文献
112.
113.
John?J.?Gilligan Nancy?E.?Vieira Alfred?L.?YergeyEmail author 《Journal of the American Society for Mass Spectrometry》2004,15(8):1123-1127
The thermochemical properties of protonated hydrates of 1,2- and 1,3-propanediols have been investigated using electrospray
ionization-high pressure mass spectrometry. The binding enthalpies, entropies, and free energies of the stepwise hydration
of protonated propanediols with one to three waters are reported. The observed negative entropy change [ΔΔS1,3o for the addition of the third water to 1,3-propanediol·H+(H2O)2 suggests a stable structure due to an increased number of hydrogen bonds and the loss of the intramolecular hydrogen bond
in the water cluster ion. The thermochemical properties of two isomers of butanediol were also investigated in order to further
elucidate the structures of the protonated propanediols. 相似文献
114.
Halloysite clay nanotubes were used as a support for the immobilization of the enzyme peroxidase from clover sprouts (Trifolium), and employed together with platinum nanoparticles in 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (Pt-BMI·PF(6)) in the development of a new biosensor for the determination of catecholamines by square-wave voltammetry. Under optimized conditions, the analytical curves showed detection limits of 0.05, 0.06, 0.07, 0.12 μM for dopamine, isoproterenol, dobutamine and epinephrine, respectively. The biosensor demonstrated high sensitivity, good repeatability and reproducibility, and long-term stability (18% decrease in response over 150 days). A recovery study of dopamine in pharmaceutical samples gave values from 97.5 to 101.4%. The proposed biosensor was successfully applied to the determination of dopamine in pharmaceutical samples, with a maximum relative error of ±1.0% in relation to the standard (spectrophotometric) method. The good analytical performance of the proposed method can be attributed to the efficient immobilization of the peroxidase in the nanoclay, and the facilitation of electron transfer between the protein and the electrode surface due to the presence of the Pt nanoparticles and ionic liquid. 相似文献
115.
We reduce the problem of factoring a semiprime integer to the problem of (numerically) integrating a certain highly oscillatory function. We provide two algorithms for addressing this problem, one based on the residue theorem and the other on the (extended) Cauchy argument principle. We show that in the former algorithm, computing the residue of the function at a certain pole leads to us obtaining the factors of the semiprime integer. In the latter, we consider a contour integral for which we are able to obtain an analytical solution with several branches. The computational difficulty reduces to that of discovering the branch of the solution which gives the precise integral. We address this problem by numerically computing an upper and a lower bound of the integral and then considering the branch that fits these bounds. The time complexity of the algorithms is left as an open problem. 相似文献
116.
Eder do Couto TavaresMarcelo Ribeiro Leite Oliveira Jan JanczakCamila Grossi Vieira Leandro de Carvalho AlvesRodrigo Antunes Castro Lígia Maria Mendonça VieiraRenata Hernandez Lindemann Genivaldo Júlio PerpétuoLeila Léa Yuan Visconte Mayura Marques Magalhães Rubinger 《Polyhedron》2012,31(1):494-501
Four zinc(II)-bis(trithiocarbimato) complexes with the general formula A2[Zn(RSO2NCS3)2] [A = Ph4P+: R = CH3 (1), 4-CH3C6H4 (2); A = Bu4N+: R = CH3 (3), 4-CH3C6H4 (4)] were obtained by the reaction of sulfur with the correspondent zinc(II)-bis(dithiocarbimato) complexes. Additionally, the compound (Ph4P)2[(CH3SO2NCS2)2S)] (5) was prepared from the potassium methylsulfonildithiocarbimate by oxidation with iodine. The compounds were characterized by elemental analyses and IR, 1H NMR and 13C NMR spectroscopies. The compounds 4 and 5 were also characterized by X-ray diffraction techniques. The compound 4 crystallizes in the centrosymmetric space group C2/c of the monoclinic system. The Zn(II) is in a distorted tetrahedral environment (ZnS4) in compound 4, and differ from the coordination mode observed in compound 1, which involves one sulfur and one nitrogen atom of each trithiocarbimate ligand. Compound 5 is the first example of a compound containing a bis(N-alkylsulfonyldithiocarbimate)-sulfide dianion and crystallises in the non-centrosymmetric space group P41212 of the tetragonal system. 相似文献
117.
118.
Luís Antônio Dantas Silva Fernanda Vieira Teixeira Raphael Caixeta Serpa Najla Locatelli Esteves Rayane Ramos dos Santos Eliana Martins Lima Marcílio Sérgio Soares da Cunha-Filho Adriano Antunes de Souza Araújo Stephânia Fleury Taveira Ricardo Neves Marreto 《Journal of Thermal Analysis and Calorimetry》2016,123(3):2337-2344
119.
An increasing interest in batch processing has been evident in recent years. This renewed interest is explained by the inherent flexibility of such plants that permits a high level of response to uncertain market conditions and requirements. This level of response does require the use of efficient tools to help the decision-making process at the design and operational level. This paper presents a Mixed Integer Linear Program (MILP) model to optimise the scheduling of batch facilities subject to changeovers and distribution constraints so as to guarantee a pre-defined objective. Such an objective can be defined as the minimum orders' total lateness or the maximum distribution units loading capacity, among others. A continuous-time representation is used as well as the concept of job predecessor and successor to effectively handle changeovers. Facilities having non-identical parallel units/lines, sequence-dependent orders, finite release times for units and orders, restrictions on the suitability of jobs to lines/units and different possible destinations to available distribution units are also considered. Based on these characteristics the proposed model is able to determine the optimal allocation of jobs to production lines/units, the sequence of jobs on every line/unit and the starting and completion production times of each order. Also, the usage and allocation of the distribution resources (eg trucks) to orders and destinations are obtained based on their availability and suitability to the orders. The model led to the development of a prototype information system that can be used as a tool to help the decision-making process at the operational plant level.Finally, the applicability of the proposed system/formulation is shown through the resolution of an industrial real case where the production of polymers is performed. 相似文献
120.
J. M. Wouters R. H. Kraus Jr. D. J. Vieira G. W. Butler K. E. G. Löbner 《Zeitschrift für Physik A Hadrons and Nuclei》1988,331(3):229-233
The direct mass measurements of the neutron-rich nuclei11Li,14Be,17B,19–20C,20–22N,23–24O, and25–27F have been performed using the Time-of-Flight Isochronous (TOFI) spectrometer. We observe a notable drop in the two-neutron separation energies for the oxygen and fluorine isotopes afterN=15. This behavior is interpreted using the shell model. 相似文献