In a general Hilbert framework, we consider continuous gradient-like dynamical systems for constrained multiobjective optimization involving nonsmooth convex objective functions. Based on the Yosida regularization of the subdifferential operators involved in the system, we obtain the existence of strong global trajectories. We prove a descent property for each objective function, and the convergence of trajectories to weak Pareto minima. This approach provides a dynamical endogenous weighting of the objective functions, a key property for applications in cooperative games, inverse problems, and numerical multiobjective optimization. 相似文献
The development of a solid-contact potentiometric sensor based on conducting rubbers using a carbon nanotubes ink is described here. Commercial rubbers are turned into conductive ones by a simple and versatile method, i.e. painting an aqueous dispersion of single-walled carbon nanotubes on the polymer surface. On this substrate, both the working ion-selective electrode and the reference electrode are built in order to form an integrated potentiometric cell. As a proof-of-principle, selective potassium electrodes are fully characterized giving comparable performances to conventional electrodes (sensitivity, selectivity, stability, linear range, limit of detection and reproducibility). As an application of the rubber-based electrodes, a bracelet was constructed to measure potassium levels in artificial sweat. Since rubbers are ubiquitous in our quotidian life, this approach offers great promise for the generation of chemical information through daily objects. 相似文献
A series of new tricyclic 1,5‐benzothiazepine derivatives were synthesized by the reaction of 1,5‐benzothiazepine containing 2‐phenoxy‐quinoline with chloracetyl chloride and phenoxyacetyl chloride. The structures of the target compounds were confirmed by IR, 1H NMR MS, and elemental analysis. 相似文献
This study describes the facile synthesis of platinum nanoparticle-containing porous carbons (Pt/C) by carbonization of freeze-dried agarose gels containing potassium tetrachloroplatinate under a nitrogen atmosphere at 800 °C. By adjusting the ratio between agarose and platinate in the freeze-dried gels, the Pt content in the final Pt/C products could be systematically varied from 0–10 wt.%. Transmission electron microscopy, inductively coupled plasma atomic emission spectrometry, X-ray photoelectron spectroscopy, Raman spectroscopy, and nitrogen physisorption measurements revealed that the Pt/C materials obtained by this method possess high surface areas (350–500 m2 g−1), narrow Pt nanoparticle size distributions (6 ± 3 nm) and nanocrystalline graphite –like carbon character. By immobilization of glucose oxidase on the surface of a 4 wt.% Pt/C electrocatalyst prepared by this route, a very sensitive amperometric glucose biosensor was obtained (response time <2 min, sensitivity 1.9 mA M−1; and a linear response with glucose concentration up to 10 mM). The simplicity and versatility of the described synthetic method suggests its application to the preparation of carbon supported noble metal catalysts including palladium/C and gold/C.
An approach for the solid-phase synthesis of apoptosis-inducing Smac peptidomimetics is presented. Using a Rink linker strategy, tetrapeptides mimicking the N-4-terminal residue of the Smac protein [(N-Me)AVPF sequence] were synthesized on PEGA resin in excellent purities and yields. Following two synthetic routes, a known tetrapeptide, incorporating a substituted proline, previously shown to exhibit excellent biological activity in vitro as well as low toxicity, was synthesized effectively on a solid support. 相似文献
This article presents recent developments on the use of inorganic nanoparticles (NPs) for environmental remediation in polluted soil, water and gas. The number of publications on these topics has grown exponentially in recent years, especially those focused on wastewater treatment. Among these topics, removal of metals has become the most popular, although some works relate to the use of nanomaterials for the elimination of nutrients (e.g., nitrogen and some persistent organic pollutants). However, this growth has not been accompanied by knowledge about the behavior of NPs once used and released into the environment. In this article, we also comment upon the current situation with respect to NP toxicology (nanotoxicology). A remarkable number of different toxicology tests has been applied to NPs, often making it very difficult to interpret or to generalize the results. We analyze in detail the bioluminescence, Daphnia magna and other tests, and give some preliminary results obtained in our work. 相似文献
The potential energy curves of the 69 Ω states generated from the 24 Λ-S states of sulfur monoxide are calculated for the first time using the internally contracted multireference configuration interaction method with the Davidson correction and the entirely uncontracted aug-cc-pV5Z basis set. Spin-orbit coupling is taken into account by the state interaction approach with the full Breit-Pauli Hamiltonian. Very good agreement is achieved between our computed spectroscopic properties and the available experimental data. The transition properties of the B(3)Σ(-) -X(3)Σ(-) and (4)1-X0(+) transitions are predicted, and our computed Franck-Condon factors and radiative lifetimes match the experimental results very well. The predissociation mechanisms are investigated, and various new predissociation channels are located. We present a new interpretation on the breaking-off of the rotational levels of the B(3)Σ(-) lower vibrational states observed in experiment, and propose that the predissociation is induced by the Coriolis coupling between the B(3)Σ(-) rovibrational levels and the A(3)Π state. Our calculations indicate that, at ν' = 9, the B(3)Σ(-) state predissociates via the C(3)Π state; around ν' = 14, three spin-orbit-induced predissociation pathways via (1)(5)Σ(+) , (2)(5)Π, and e(1)Π would be open; around ν' = 17, the pathways via (2)(1)Σ(+) , (2)(3)Σ(+) and (2)(5)Σ(+) would contribute. These satisfactorily explain the experimental results about the diffuseness of the B(3)Σ(-) bands. Furthermore, various predissociation pathways of the C'(3)Π state are predicted, through which the C'(3)Π state could predissociate rapidly. 相似文献
Photoresponsive monolayers of hydrophilically substituted azobenzenes have been prepared by reaction on aminosilane monolayers on silicon surfaces. Grafting densities in the 0.2-1.0 molecule/nm(2) range were determined by X-ray reflectometry. The monolayers exhibit reversible photoisomerization, switching from a more hydrophilic trans state to a less hydrophilic cis state upon UV irradiation, in contrast with the usual behavior of most azobenzene monolayers that switch from a less to a more hydrophilic state. This indicates that the wettability is not dominated by the change in the dipole moment of the azobenzene moiety but originates from variations in the composition of the outer surface of the monolayers resulting from the reorientation of the substituent groups. The light-driven change in the water contact angle correlates linearly with the grafting density but remains small. However, the wettability contrast can be increased by forcing the molecules to stand in an improved vertical orientation, either by densifying the underlying aminosilane monolayer or by filling the voids left at the bottom of the layer of grafted azobenzene molecules. 相似文献