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排序方式: 共有388条查询结果,搜索用时 46 毫秒
11.
Portilla-Sangabriel Melisa Arzate Sandra Macías-Vargas José-Alberto Ramírez-Zamora Rosa-María 《Topics in Catalysis》2021,64(1-2):181-193
Topics in Catalysis - The use of the magnetic fraction (MF) of a low-grade titanium ore (TO) and two oxidants (H2O2 and NaClO), testing each one separately, were compared in photo-Fenton like... 相似文献
12.
13.
João Paulo Gois Diogo Fernando Trevisan Harlen Costa Batagelo Ives Macêdo 《The Visual computer》2013,29(6-8):651-661
In this work we investigate a generalized interpolation approach using radial basis functions to reconstruct implicit surfaces from polygonal meshes. With this method, the user can define with great flexibility three sets of constraint interpolants: points, normals, and tangents; allowing to balance computational complexity, precision, and feature modeling. Furthermore, this flexibility makes possible to avoid untrustworthy information, such as normals estimated on triangles with bad aspect ratio. We present results of the method for applications related to the problem of modeling 2D curves from polygons and 3D surfaces from polygonal meshes. We also apply the method to problems involving subdivision surfaces and front-tracking of moving boundaries. Finally, as our technique generalizes the recently proposed HRBF Implicits technique, comparisons with this approach are also conducted. 相似文献
14.
Autonomous Robots - Dynamic games are an effective paradigm for dealing with the control of multiple interacting actors. This paper introduces augmented Lagrangian GAME-theoretic solver (ALGAMES),... 相似文献
15.
María Silvina Juárez Tomás Elena Bru María Elena Nader‐Macías 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2010,85(1):91-99
BACKGROUND: The culture medium for optimal growth of vaginal Lactobacillus salivarius CRL 1328 is different from that for optimal bacteriocin production. To simultaneously obtain high amount of biomass and bacteriocin of this microorganism, the effects of different basal culture media and salts on both responses were evaluated. The study was performed by using a complete factorial experimental design 26, with central points. Sixty‐four different growth media, which resulted from the combinations of two basal culture media and two concentrations of five salts (ammonium citrate, sodium acetate, MgSO4, MnSO4, and K2HPO4) were assayed. RESULTS: Only the addition of MnSO4 to each culture medium significantly stimulated the growth of L. salivarius. The presence of sodium acetate or MgSO4 stimulated the bacteriocin production, while MnSO4 and K2HPO4 exerted an inhibitory effect. However, the simultaneous addition of MnSO4 and sodium acetate to both basal culture media allowed high bacteriocin levels to be reached, attenuating the inhibitory effect of Mn2+. CONCLUSIONS: The application of a complete experimental design contributed to simultaneous optimization of the biomass and bacteriocin production of L. salivarius CRL 1328. The results obtained are potentially applicable to the technological production of probiotic bacteria and antagonistic substance to be included in a probiotic pharmaceutical product. Copyright © 2009 Society of Chemical Industry 相似文献
16.
Francisco Carvajal-Ramos Alejandro González-Álvarez J. Roger Vega-Acosta Donato Valdez-Pérez Víctor Vladimir Amilcar Fernández Escamilla Emma Rebeca Macías Balleza J. Félix Armando Soltero Martínez 《Journal of surfactants and detergents》2011,14(2):269-279
The temperature–composition phase diagram in the diluted region of the cationic surfactant cetyldimethylbenzylammonium salicylate/water
system was studied with a battery of techniques. The Krafft temperature (T
k = 33 ± 1 °C) was measured by differential scanning calorimetry, polarizing microscopy, conductimetry, viscosimetry, and rheometry.
The critical vesicle concentration (cvc, ~0.002 wt%) and a vesicle–micellar transition (cvm, ~0.005 wt%) was detected at a
temperature of 35 °C. Below T
k and concentrations ≤2 wt%, a transparent solution is formed (I). Above 2–8.5 wt%, a lamellar (L1) phase forms. At higher concentrations and up to 12 wt%, a second lamellar phase (L2) is detected. From 12.4 to 15.5 wt%, an emulsion phase (E) is formed. Rheological dynamic measurements for the I phase indicate
that the system exhibits a predominantly viscous behavior (G′ < G″) for concentrations lower than the overlap or entanglement concentration (C
e, ~0.75 wt%). At higher concentrations, wormlike micelles form and the elastic behavior predominates (G′ > G″). The elastic (G′) modulus collapses in a concentration–time master curve in the whole reduced frequencies range ωτ
c examined, whereas the viscous modulus (G″) collapses only at reduced frequencies lower than 0.1. Reduced stress plotted as a function of the reduced shear rate yields
a good superposition of the curves at the different concentrations up to the onset of the non-linear behavior. 相似文献
17.
C. Macías P. Lavela G. Rasines M. C. Zafra J. L. Tirado C. O. Ania 《Journal of Applied Electrochemistry》2014,44(8):963-976
Three-activated carbon aerogels were synthesized by CO2 activation of the materials prepared by the polycondensation of resorcinol and formaldehyde mixtures followed by supercritical drying. The obtained carbon aerogels were characterized and used as electrode materials for the electrosorption of sodium phosphate and nitrate. X-ray diffraction and Raman spectroscopy showed the dependence of the structural ordering of the aerogels with the resorcinol/catalyst ratio and the extent of activation. The electrosorption capacitance evaluated by cyclic voltammetry revealed large values for the activated samples containing a large contribution of mesopores, regardless the electrolyte salt. Due to an adequate combination of chemical and porous features, the desalting capacity of the activated carbon aerogel electrodes exceeded that of the as-prepared materials. The evaluation of the kinetic properties by chronocoulometric relaxation and impedance spectroscopy showed a decrease of time constant and resistances for highly mesoporous activated samples. A high deionization capacity and fast electrode discharge was detected for the deionization of sodium nitrate on the highly mesoporous activated aerogel. Data also showed the efficient electrosorption of ionic species on consecutive charge/discharge cycles, confirming the stability of the aerogel electrodes at the high applied potentials. 相似文献
18.
Neil Mac Parthaláin Author Vitae Author Vitae 《Pattern recognition》2009,42(5):655-667
Of all of the challenges which face the effective application of computational intelligence technologies for pattern recognition, dataset dimensionality is undoubtedly one of the primary impediments. In order for pattern classifiers to be efficient, a dimensionality reduction stage is usually performed prior to classification. Much use has been made of rough set theory for this purpose as it is completely data-driven and no other information is required; most other methods require some additional knowledge. However, traditional rough set-based methods in the literature are restricted to the requirement that all data must be discrete. It is therefore not possible to consider real-valued or noisy data. This is usually addressed by employing a discretisation method, which can result in information loss. This paper proposes a new approach based on the tolerance rough set model, which has the ability to deal with real-valued data whilst simultaneously retaining dataset semantics. More significantly, this paper describes the underlying mechanism for this new approach to utilise the information contained within the boundary region or region of uncertainty. The use of this information can result in the discovery of more compact feature subsets and improved classification accuracy. These results are supported by an experimental evaluation which compares the proposed approach with a number of existing feature selection techniques. 相似文献
19.
Bibliometric analysis of AIDS literature in Central Africa 总被引:1,自引:0,他引:1
The purpose of this paper is to present the preliminary results of a bibliometric analysis of AIDS documents as produced on
Sub-Saharan Africa. AIDSLINE 1980-2000 was used to conduct the literature search. In this paper, an analysis was made only
of the records retrieved under "Central Africa". Bibexcel (version 2001) and Microsoft Excel (2000) were used as software
tools to conduct the analysis of the records. Seven countries and 1052 records were identified. Main participating countries
were Democratic Republic of the Congo (527 documents), and Cameroon (271). Results indicated a high pattern of collaboration
through multiple authorship. Most documents were published in English (84.50%) and French (14.73%). Over 57% corresponded
to journal articles. The subject content of the documents was mainly focused on epidemiological, complications, and prevention
& control issues on ‘HIV Infections’ and ‘Acquired Immunodeficiency Syndrome’. Countries behind this productivity were Cameroon,
USA, Democratic Republic of the Congo, France, and Belgium. Comparison of results among Central African countries and among
other developing countries is made by the authors.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
20.