RESUMEN
Catalysis based on two-dimensional silicon has been under intense investigation recently. However, its substandard catalytic activity is far from industrialization. In this work, we demonstrate a new solution to this problem formulated on the batch synthesis of siloxene with an enhanced specific surface area (217.8 m2 g-1). A two-dimensional porous structure was prepared, enabling great support and dispersion of metal nanoparticles. Catalytic evaluations of such hybrid structures for the (photo)thermal CO2 hydrogenation reaction and the electrochemical hydrogen evolution reaction revealed a significant performance advantage over the benchmark two-dimensional silicon structures synthesized via the conventional method. This work may confer notable viability on two-dimensional silicon for advanced energy, catalytic, and environmental applications.
RESUMEN
Bullying experiences play an important role in non-suicidal self-injury (NSSI). However, little is known about how and in what conditions different bullying experiences (i.e., experiences of being pure bullies, pure victims, and bully-victims) may influence NSSI. Guided by the transactional model of development and the integrated model of NSSI, the current study investigated two potential mediators (i.e., peer acceptance and depressive symptoms) and one potential moderator (i.e., psychological resilience) of the relations between different bullying experiences and NSSI. Participants were 812 Chinese adolescents (43% female; Mage at Wave 1 = 13.15 years) from a two-wave longitudinal study with data spanning 1 year. The results show that all three types of bullying experiences can relate to a higher likelihood of NSSI through two indirect pathways: (a) lower peer acceptance to more depressive symptoms, or (b) more depressive symptoms. These indirect effects were weaker for adolescents with higher (versus lower) levels of psychological resilience. Moreover, when bully-victims were distinguished from pure bullies and pure victims and the unique effects for all three groups were tested, the direct and indirect effects were most evident among bully-victims. These findings imply that it is necessary to distinguish bully-victims from pure bullies and pure victims. The results indicate that NSSI may be effectively reduced if interventions focus on promoting peer acceptance and reducing adolescent depressive symptoms, particularly for bully-victims with lower levels of psychological resilience.
Asunto(s)
Acoso Escolar , Víctimas de Crimen , Conducta Autodestructiva , Adolescente , China , Femenino , Humanos , Estudios Longitudinales , Masculino , Grupo ParitarioRESUMEN
Described herein is a Pd-catalyzed haloallylation of aromatic ynol ethers and allyl chlorides, allowing facile access to (1E)-α-chloroenol ethers in a highly regio- and stereoselective manner. The synthetic utility of this method is demonstrated well by the synthesis of the stereodefined multisubstituted enol ethers and α-allylated carbonyl compounds.
RESUMEN
A highly regio- and stereoselective method for the synthesis of cis-1,2-dihaloalkenes through Pd-catalyzed coupling of haloalkynes and α,ß-unsaturated carbonyls has been reported. Excellent stereoselectivities (Z/E up to >98:2) were observed in most cases. This method was subsequently applied to synthesize the functionalized conjugated enyne via the mono-Sonogashira coupling reaction of cis-1-chloro-2-iodoalkene.
Asunto(s)
Aldehídos/química , Alquenos/química , Alquenos/síntesis química , Alquinos/química , Halógenos/química , Cetonas/química , Paladio/química , Catálisis , Estereoisomerismo , Especificidad por SustratoRESUMEN
A highly efficient and selective synthesis of (1E)- or (1Z)-1,2-dihalo-1,4-dienes via Pd-catalyzed coupling of haloalkynes and allylic halides is described. The (1E)-1,2-dihalo-1,4-dienes were generated in good yields with excellent stereoselectivities (1E/1Z up to >98/2), while (1Z)-1,2-dihalo-1,4-dienes were produced in excellent yields and stereoselectivities (1Z/1E up to >98/2) by simply adding stoichiometric lithium halides.
RESUMEN
The asymmetric unit of title compound, [La(NO(3))(3)(C(15)H(15)NO(2))(2)(CH(3)OH)], consists of two Schiff base 2-meth-oxy-6-[(4-methyl-phen-yl)iminiometh-yl]phenolato (HL) ligands, three independent nitrate anions and one methanol mol-ecule coordinated to La(III). The coordination environment of the La(III) ion is formed by eleven O atoms. Three bidentate nitrate anions coordinate to the La(III) ion, while two HL ligands chelate the metal center with O atoms from the phenolate and meth-oxy groups. The HL ligands are zwitterionic, with protonated imine N atoms. The coordination sphere is completed by one methanol mol-ecule. The protonated imine N atoms are involved in intra-molecular N-Hâ¯O hydrogen bonds with the phen-oxy groups and nitrate ligands. One O atom of one nitrate group is disordered over two sites of equal occupancy.