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排序方式: 共有351条查询结果,搜索用时 203 毫秒
1.
Ortiz Adolfo Yang Jianhua Coccolo Mattia Seoane Jesús M. Sanjuán Miguel A. F. 《Nonlinear dynamics》2020,102(4):2323-2337
Nonlinear Dynamics - The main purpose of this paper is to study both the underdamped and the overdamped dynamics of the nonlinear Helmholtz oscillator with a fractional-order damping. For that... 相似文献
2.
Silvio Curia Feifei Ng Marie-Emrentienne Cagnon Victor Nicoulin Adolfo Lopez-Noriega 《Molecules (Basel, Switzerland)》2021,26(5)
This article presents the evaluation of diblock and triblock poly(ethylene glycol)-b-poly(1,3-trimethylene carbonate) amphiphilic copolymers (PEG-PTMCs) as excipients for the formulation of long-acting injectables (LAIs). Copolymers were successfully synthesised through bulk ring-opening polymerisation. The concomitant formation of PTMC homopolymer could not be avoided irrespective of the catalyst amount, but the by-product could easily be removed by gel chromatography. Pure PEG-PTMCs undergo faster erosion in vivo than their corresponding homopolymer. Furthermore, these copolymers show outstanding stability compared to their polyester analogues when formulated with amine-containing reactive drugs, which makes them particularly suitable as LAIs for the sustained release of drugs susceptible to acylation. 相似文献
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Nora Jannsen Dr. Stefano Diodati Nicola Dengo Francesca Tajoli Dr. Nicola Vicentini Dr. Giacomo Lucchini Prof. Adolfo Speghini Prof. Denis Badocco Prof. Paolo Pastore Prof. Silvia Gross 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(59):13624-13634
The aim of this work was i) to develop a hydrothermal, low-temperature synthesis protocol affording the upconverting hexagonal phase NaYF4 with suitable dopants while adhering to the “green chemistry” standards and ii) to explore the effect that different parameters have on the products. In optimizing the synthesis protocol, short reaction times and low temperatures (below 150 °C) were considered. Yb3+ and Er3+ ions were chosen as dopants for the NaYF4 material. Within the context of the second goal, parameters including nature of the precursors, treatment temperature, and treatment time were investigated to afford a pure hexagonal crystalline phase, both in the doped and undoped materials. To fully explore the synthesis results, the prepared materials were characterized from a structural (XRD), compositional (XPS, ICP-MS), and morphological (SEM) point of view. The upconverting properties of the compounds were confirmed by photoluminescence measurements. 相似文献
4.
César Adolfo Melo Hernández Edgar Yesid Lancheros Mayorga 《Mathematische Nachrichten》2020,293(4):721-734
In this paper, information about the instability of equilibrium solutions of a nonlinear family of localized reaction-diffusion equations in dimension one is provided. More precisely, explicit formulas to the equilibrium solutions are computed and, via analytic perturbation theory, the exact number of positive eigenvalues of the linear operator associated to the stability problem is analyzed. In addition, sufficient conditions for blow up of the solutions of the equation are also discussed. 相似文献
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Dr. Cristian Guerra Dr. Leandro Ayarde-Henríquez Dr. Yeray A. Rodríguez-Núñez Prof. Adolfo Ensuncho Prof. Dr. Eduardo Chamorro 《Chemphyschem》2023,24(11):e202200867
In this study, we revealed the significance of chemical bonding for the photochemically induced mechanism of 2-phenyl tetrazole derivatives generating nitrile imines. The correlated electron localization function shows that the formation of imine nitrile involves two key bond events: (i) the heterolytic C−N breakage taking place in the T1 state and (ii) the homolytic N−N rupture occurring in the T2 excited state. In particular, a cation-radical specie results from the C−N cleavage, whereas the N−N rupture creates a biradical resonant form of imine nitrile. Additionally, we noticed that the substantial pair delocalization of the C−C-N bonded structure could play a significant role in the conversion of the biradical imine nitrile into both the propargylic and allenic forms via the T1→S0 deactivation. 相似文献
7.
Ballester-Bolinches A. Esteban-Romero R. Jiang Qinhui Li Xianhua 《Annali di Matematica Pura ed Applicata》2015,194(1):77-86
Annali di Matematica Pura ed Applicata (1923 -) - In this paper families of non-nilpotent subgroups covering the non-nilpotent part of a finite group are considered. An $$A_5$$ -free group... 相似文献
8.
Adolfo Zavelani-Rossi 《Meccanica》1974,9(4):312-324
Summary Limit analysis of plane structures is formulated by applying a finite element linear programming technique that was previously proposed by the same author.Three different element models are considered: the constant stress compatible model, the linear stress equilibrium model, the quadratic stress equilibrium model. Some notes are devoted to the construction of the stress fields with reference to the adopted method.Some suitably chosen numerical applications are then proposed in order to compare the different approaches as far as numerical efficiency and result accuracy are concerned. The possibility of improving the linear programming procedure is also discussed, and in particular a method is proposed to find out an initial feasible vector on the basis of mechanical considerations, in order to overcome the necessity of the so-called M-phase of the simplex method.Numerical results are given together with the comments.
Research supported by the C.N.R. (Italian National Research Council). 相似文献
Sommario Si formula il problema dell'analisi limite di strutture piane secondo un metodo degli elementi finiti già proposto dall'autore.Nel presente lavoro vengono considerati tre diversi modelli di elementi e precisamente: il modello congruente a sforzo costante e quelli equilibrati a campi di sforzo lineare e quadratico. La costruzione dei tre modelli viene presentata in dettaglio nell'ambito del metodo adottato.Vengono quindi presentati alcuni esempi di applicazione opportunamente scelti, con lo scopo di confrontare l'efficienza numerica e l'accuratezza di risultati ottenuti con l'impiego dei tre modelli. Si discute inoltre la possibilità di migliorare l'efficacia dell'algoritmo matematico ed in particolare si suggerisce un metodo che, individuando una soluzione ammissibile di partenza sulla scorta di considerazioni meccaniche, permette di evitare la cosiddetta fase M della programmazione lineare.I commenti sono accompagnati dai risultati numerici.
Research supported by the C.N.R. (Italian National Research Council). 相似文献
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