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Valter Castelvetro Cinzia De Vita Giacomo Giannini Simone Giaiacopi 《应用聚合物科学杂志》2006,102(4):3083-3094
The evolution of the main colloidal parameters in the seeded starved‐feed semi‐continuous emulsion polymerization of butyl methacrylate (BMA) was investigated, with the main purpose of assessing the effectiveness of the semi‐empirical relationship S = K · SS · ΔA/AS as a tool to define the surfactant/monomer feed ratio (∝ K) best suited to achieve a target particle size. In particular, the effect of the type and amount of surfactant [i.e., anionic, sodium dodecyl sulfate (SDS), or nonionic, Brij 58P] added during the semi‐continuous stage was considered. Coagulum formation was never observed under the adopted experimental conditions. To detect the occurrence of secondary nucleation or particle aggregation, or both, the particle size and number of particles, the surface tension and the particle surface coverage ratio were correlated. The best results were obtained with SDS and 0.8 ≤ K ≤ 3. In fact, under the selected experimental conditions, only with SDS did the number of particles remain nearly constant throughout the polymerization at the value defined by the seed latex; the particle size distribution was highly monodisperse, and the final particle diameter closely matched the calculated one (~ 120 nm). The above semi‐empirical relationship based on the adjustable parameter K was validated by running test polymerizations aimed at lattices with well‐defined particle size. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3083–3094, 2006 相似文献
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Raman Scattering Mapping: Sensitive and Reproducible Immunoassay of Multiple Mycotoxins Using Surface‐Enhanced Raman Scattering Mapping on 3D Plasmonic Nanopillar Arrays (Small 39/2018) 下载免费PDF全文
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Cosimo Pallavicini 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1982,175(4):249-252
Summary Changes in peptides and their amino-acid composition that take place during the plastein reaction carried out with immobilized-chymotrypsin as a catalyst and with the low-molecular weight peptide fraction of alfalfa (Medicago sativa) leaf protein hydrolyzate as substrate were studied. By thin-layer fingerprint chromatography the substrate and the plastein reaction product exhibited five and six peptide species, respectively. The analysis of their amino-acid composition indicated that the substrate peptides in two cases gave rise to plastein peptides by slight apparent compositional changes, in the other cases instead they underwent more pronounced modifications.
This work was supported by the Consiglio Nazionale delle Ricerche, Roma, Italy 相似文献
Veränderungen einiger Peptide aus Luzerneblattproteinen als Ergebnis einer Plastein-Reaktion mit immobilisiertem -Chymotrypsin
Zusammenfassung Es wurden Veränderungen der Peptide und deren Aminosäuren-Zusammensetzung im Laufe der Plastein-Reaktion erforscht, die mit Hilfe von als Katalysator wirkenden immobilisiertem -Chymotrypsin und einer Peptid-Fraktion mit niedrigem Molekulargewicht aus einem Hydrolysat von Luzerneproteinen (Medicago sativa) als Substrat durchgeführt wurde. Durch Dünnschichtfingerabdruck-Chromatographie zeigten Substrat und Produkt der Plastein-Reaktion fünf bzw. sechs Peptide. Die Analysen ihrer Aminosäuren-Zusammensetzung zeigte in zwei Fällen, daß die Substratpeptide in Plasteinpeptide übergingen, bei scheinbar geringen Veränderungen in der Zusammensetzung. In den übrigen Fällen ergaben sich tiefgreifendere Veränderungen.
This work was supported by the Consiglio Nazionale delle Ricerche, Roma, Italy 相似文献
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This article presents a detailed procedure to learn a nonlinear model and its derivatives to as many orders as desired with multilayer perceptron (MLP) neural networks. A modular neural network modeling a nonlinear function and its derivatives is introduced. The method has been used for the extraction of the large‐signal model of a power MESFET device, modeling the nonlinear relationship of drain‐source current Ids as well as gate and drain charge Qg and Qd with respect to intrinsic voltages Vgs and Vds over the whole operational bias region. The neural models have been implemented into a user‐defined nonlinear model of a commercial microwave simulator to predict output power performance as well as intermodulation distortion. The accuracy of the device model is verified by harmonic load‐pull measurements. This neural network approach has demonstrated to predict nonlinear behavior with enough accuracy even if based only on first‐order derivative information. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 13: 276–284, 2003. 相似文献
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The hydrodynamic transport equations for charges in a semiconductor have been solved for a periodic excitation by means of a harmonic approach, in order to model microwave and millimetre-wave active devices. The solution is based on the expansion of physical variables in a Fourier series in the time domain, and on discretisation in the space domain. A waveform-balance technique in the TD is used to solve the nonlinear equations system. This approach allows for a longer time step with respect to standard TD solutions for most cases of interest, greatly reducing simulation time by at least two orders of magnitude in typical cases. © 2003 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14: 36–48, 2004. 相似文献
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Francesco Merola Simonetta Grilli Sara Coppola Veronica Vespini Sergio De Nicola Pasquale Maddalena Cosimo Carfagna Pietro Ferraro 《Advanced functional materials》2012,22(15):3267-3272
Investigation on the behavior of nematic liquid crystals on functionalized polar dielectric crystal substrates is accomplished. Very interesting effects can be observed in maneuvering liquid crystal droplets on the substrate surface, driven by electric fields generated by pyroelectric effect. Reversible drops fragmentation and self‐assembling in different configurations can be achieved. The dynamics of the observed phenomena is studied and the repeatability of the process is full assessed. 相似文献
10.
Shah Ghazanfar Ali Polette Arnaud Pernot Jean-Philippe Giannini Franca Monti Marina 《Engineering with Computers》2021,37(4):2891-2909
Engineering with Computers - This paper introduces a new fitting approach to allow an efficient part-by-part reconstruction or update of editable CAD models fitting the point cloud of a digitized... 相似文献