236 research outputs found
Nota sobre un bando de Corvus monedula (Grajilla) avistado en Arévalo (Ávila) el 3 de agosto de 1954
No full textNota sobre un bando de 1200 Corvus monedula (Grajilla, llamada Coloeus por el autor) avistado en Arévalo (Ávila) la tarde del 3 de agosto de 1954, dirigiéndose hacia un pinar.Note about a flock of 1200 Corvus monedula (Eurasian Jackdaw, refered as Coloeus by the author) observed at Arévalo (Ávila) the evening of the 3rd of August of 1954, going to a pine forest
One-dimensional CdS nanostructures: synthesis, properties, and applications
No full textOne-dimensional (1D) semiconductor nanostructures are of prime interest due to their potential in investigating the size and dimensionality dependence of the materials' physical properties and constructing nanoscale electronic and optoelectronic devices. Cadmium sulfide (CdS) is an important semiconductor compound of the II-VI group, and its synthesis and properties have been of growing interest owing to prominent applications in several fields. This article provides a comprehensive review of the state-of-the-art research activities that focus on the rational synthesis, novel properties and unique applications of 1D CdS nanostructures in nanotechnology. It begins with the rational design and synthesis of 1D CdS nanostructures, and then highlights a range of unique properties and applications (e.g. photoluminescence, cathodoluminescence, electrochemiluminescence, photocatalysis, lasers, waveguides, modulators, solar cells, field-effect transistors, photodetectors, field-emitters, and nanogenerators) associated with them. Finally, the review is concluded with the author outlook of the perspectives with respect to future research on 1D CdS nanostructures
La policía bonaerense en la primera década independiente: el bando del alcalde de la hermandad del partido de San Fernando de Buena Vista y puerto de Las Conchas (1818)
No full textAs part of an investigation focused on the police commandments issued in Buenos Aires between 1810 and 1821, we presented the bando published in San Fernando de Buena Vista on February 8, 1818, by the alcalde de la Hermandad José Joaquín de La Madrid. Based on unpublished documents from the Archivo General de la Nación, acts of the extinct cabildo of Buenos Aires, orders and instructions to the alcaldes de la Hermandad, newspapers and contemporary testimonies, we turn first to the author and then study the text itself, examining aspects of their development and promulgation, publication, diplomatic description and normative content, appeal and application. En el marco de una investigación centrada en los mandamientos que en materia de policía se dieron en Buenos Aires entre 1810 y 1821, presentamos el bando expedido en San Fernando de Buena Vista el 8 de febrero de 1818, por el alcalde de la Hermandad del partido de San Fernando de Buena Vista y puerto de Las Conchas, José Joaquín de La Madrid. Sobre la base de documentación inédita del Archivo General de la Nación, los acuerdos del extinguido cabildo de Buenos Aires, las órdenes e instrucciones dadas para los alcaldes de la Hermandad, periódicos y testimonios de contemporáneos, nos ocuparemos en primer lugar de su autor, para luego estudiar el texto del bando propiamente dicho, analizando aspectos relacionados con su elaboración y promulgación, publicación, descripción diplomática y contenido normativo, apelación y aplicación.
Le idee invendute di un'umanità all'asta : un'interpretazione di "Bando" nell'opera di Sergio Corazzini
No full textSpesso letta come eccezione d’ironia e vivacità, "Bando" s’inscrive pienamente, invece, nel panorama poetico corazziniano, e ne è l’ideale coronamento, posta com’è a chiudere il "Libro per la sera della domenica", ultima raccolta pubblicata vivente il poeta. La corrosione, ora tutta umana, dell’ambiente dell’asta, le tensioni all’animalità e a un’escatologia dell’abbandono del sé sono i termini più vistosi di questa continuità con l’intera opera di Corazzini, di cui si propone un rapido ma esteso excursus, che si avvale in particolare di un proficuo confronto con il crepuscolarismo brasiliano di Manuel Bandeira. La concitazione dell’asta si ribalta in vana preghiera a passanti disinteressati all’idea in sé, morte, suicidio, prostituzione paiono riemergere, sommersi, da più di un luogo del testo, richiamando esperienze centrali del Corazzini della "Desolazione", delle "Dolcezze" o delle prose. È distinguendo, pur nella difficoltà del contesto lirico, tra un “io che batte l’asta” e un “io poetante” che si perviene alla definizione di un tono duplice: la supplica orante del banditore disperato da un lato, dall’altro la denuncia inesorabile di una crisi, che investe, più che la vendibilità in sé delle idee, il sostanziale disinteresse che esse generano nel potenziale uditorio di offerenti, l’umanità.Generally read as an ironic or playful exception, "Bando", instead, perfectly places itself in Corazzini’s poetical production, and can be considered an ideal achievement of it, also considering its relevant position in conclusion of "Libro per la sera della domenica", the last collection published by the author still alive. The human corruption of the auction milieu, the tensions to bestiality and self-loosing are the most remarkable aspects of this continuity with the rest of Corazzini’s poems, of which is purposed a fast but extended excursus, developed by a dialogue with crepuscular directions of Brazilian modernism, especially expressed by Manuel Bandeira. The agitation of the auction reverses itself in an useless prayer addressed to uninterested people; death, suicide, prostitution seem resurface from more than one verse, recalling the central experiences of Corazzini’s "Desolazione", "Dolcezze" and prose works. Only distin guishing, despite of the difficulty of lyric contest, an "I-auctioneer" and an "I lyricist", it is possible to define a double tone: on the one hand, the oratory plea of the desperate auctioneer; on the other hand, the lyric denunciation of a crisis which attacks, more than the dealing of ideas, their interest for an only potential public of bidders, that is mankind
BN nanospheres as CpG ODN carriers for activation of toll-like receptor 9
No full textFor the first time, we demonstrated BN nanospheres (BNNSs) can interact with biomolecules and deliver unmethylated cytosine-phosphate-guanine oligodeoxynucleotides (CpG ODNs) into cells to activate toll-like receptor 9 (TLR9), which is a very important process for therapy of cancers and allergy diseases
Tunneling microscopy of NbSe2 in air
No full textPT: J; CR: BANDO H, 1987, JPN J APPL PHYS PT 2, V26, L41 BINNIG G, 1982, PHYS REV LETT, V49, P57 BRYANT A, 1986, APPL PHYS LETT, V48, P832 FELDMAN JL, 1976, J PHYS CHEM SOLIDS, V37, P1141 FELDMAN JL, 1981, J PHYS CHEM SOLIDS, V42, P1029 JERICHO MH, 1980, PHYS REV B, V22, P4907 JERICHO MH, 1987, REV SCI INSTRUM, V58, P1349 MAMIN HJ, 1986, PHYS REV B, V34, P9015 PETHICA JB, 1986, IBM J RES DEV, V30, P455 RAO GVS, 1979, PHYSICS CHEM MATERIA, P99 SOLER JM, 1986, PHYS REV LETT, V57, P444 TERSOFF J, 1986, PHYS REV LETT, V57, P440 TOKUMOTO H, 1986, JPN J APPL PHYS, V25, L621; NR: 13; TC: 14; J9: J APPL PHYS; PG: 4; GA: L5219Source type: Electronic(1
Phonon-assisted electron emission from individual carbon nanotubes
No full textA question of how electrons can escape from one-atom-thick surfaces has seldom been studied and is still not properly answered. Herein, lateral electron emission from a one-atom-thick surface is thoroughly studied for the first time. We study electron emission from side surface of individual electrically biased carbon nanotubes (CNTs) both experimentally and theoretically and discover a new electron emission mechanism named phonon-assisted electron emission. A kinetic model based on coupled Boltzmann equations of electrons and optical phonons is proposed and well describes experimentally measured lateral electron emission from CNTs. It is shown that the electrons moving along a biased CNT can overflow from the one-atom-thick surface due to the absorption of hot forward-scattering optical phonons. A low working voltage, high emission density, and side emission character make phonon-assisted electron emission primarily promising in electron source applications
Local Coulomb explosion of boron nitride nanotubes under electron beam irradiation
No full textIn many previous reports, the engineering of nanostructures using electron beam irradiation (EBI) in a high vacuum has primarily been based on the knock-on atom displacement. Herein, we report a new phenomenon under EBI that can also be effectively used to engineer a nanostructure: local Coulomb explosion (LCE) of cantilevered multiwalled boron nitride nanotubes (BNNTs) resulted from their profound positive charging. The nanotubes are gradually shortened, while the tubular shells at free ends are torn into graphene-like pieces and then removed during LCE. The phenomenon is dependent not only on the characteristics of an incident electron beam, as in the case of a common knock-on process, but also on the cantilevered tube length. Only after the electron beam density and tube length exceed the threshold values can LCE take place, and the threshold value for one of the parameters decreases with increasing the value of the other one. A model based on the diffusion of electron-irradiation-induced holes along a BNNT is proposed to describe the positive charge accumulation and can well explain the observed LCE. LCE opens up an efficient and versatile way to engineer BNNTs and other dielectric nanostructures with a shorter time and a lower beam density than those required for the knock-on effect-based engineering
Electric-field-direction dependent spatial distribution of electron emission along electrically biased carbon nanotubes
No full textThe spatial distribution of lateral electron emission from individual electrically biased carbon nanotubes (CNTs) along the tube axis is resolved for the first time by combining multiprobe simultaneous emission current collection and electron trajectory simulations. The spatial distribution is found to be asymmetric along the tube axis and depends on the direction of the electric field in CNTs. The average emission density of the half tube with a higher electric potential is higher than that of the other half with a lower electric potential. The electric-field-direction dependent asymmetric spatial distribution of the electron emission is absent in all pre-existing well-established mechanisms but is well explained in terms of the recently proposed phonon-assisted electron emission (PAEE). This, together with a quantitative description of experimentally measured emission currents, provides solid evidence for the validity of the PAEE mechanism. PAEE from CNTs is predicted to take place near room temperature; thus, it opens up a new and promising route for fabricating cold electron emitters with a high emission density and a low working voltage.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000297414500042&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Physics, Condensed MatterSCI(E)5ARTICLE19null8
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