980 resultados para Calendar, Julian.
Resumo:
This paper reviews recent experimental activity in the area of optimization, control, and application of laser accelerated proton beams, carried out at the Rutherford Appleton Laboratory and the Laboratoire pour l’Utilisation des Lasers Intenses 100 TW facility in France. In particular, experiments have investigated the role of the scale length at the rear of the plasma in reducing target-normal-sheath-acceleration acceleration efficiency. Results match with recent theoretical predictions and provide information in view of the feasibility of proton fast-ignition applications. Experiments aiming to control the divergence of the proton beams have investigated the use of a laser-triggered microlens, which employs laser-driven transient electric fields in cylindrical geometry, enabling to focus the emitted
protons and select monochromatic beam lets out of the broad spectrum beam. This approach could be advantageous in view
of a variety of applications. The use of laser-driven protons as a particle probe for transient field detection has been developed and
applied to a number of experimental conditions. Recent work in this area has focused on the detection of large-scale self-generated magnetic fields in laser-produced plasmas and the investigation of fields associated to the propagation of relativistic electron both on the surface and in the bulk of targets irradiated by high-power laser pulses.
Resumo:
N-Tosyl-5,5-divinyloxazolidin-2-one undergoes a palladium-catalyzed decarboxylative cyclization across a range of electrophilic alkenes to give the corresponding pyrrolidine derivatives bearing two contiguous quaternary centres. Alkenes bearing two electron-withdrawing groups are required; pyrrolidines were not formed from mono-activated alkenes. Bulky, electron-rich phosphines promote pyrrolidine formation with less highly electrophilic, doubly activated alkenes, and a dramatic improvement is observed in the presence of iodide.
Resumo:
El presente artículo investiga de qué forma la centralidad del sufrimiento en la filosofía de Schopenhauer sirve para fundamentar su pesimismo. Tres son los argumentos analizados: el lugar del sufrimiento en el mundo, su lugar en la conciencia humana y su lugar frente a la felicidad. A la luz de estos tres argumentos, se destaca que el vínculo indisoluble entre el sufrimiento y la esencia del mundo, la determinación del sufrimiento en la conciencia, tanto en su génesis como en su intensidad, y su anterioridad ontológica frente a la felicidad hacen del pesimismo una categoría necesaria. Finalmente, se señala una posible contribución del pesimismo schopenhaueriano a la crítica social contemporánea, considerando la idea de mundo que el capitalismo tardío promueve.
Resumo:
The United States Supreme Court case of 1991, Feist Publications, Inc. v. Rural Tel. Service Co., continues to be highly significant for property in data and databases, but remains poorly understood. The approach taken in this article contrasts with previous studies. It focuses upon the “not original” rather than the original. The delineation of the absence of a modicum of creativity in selection, coordination, and arrangement of data as a component of the not original forms a pivotal point in the Supreme Court decision. The author also aims at elucidation rather than critique, using close textual exegesis of the Supreme Court decision. The results of the exegesis are translated into a more formal logical form to enhance clarity and rigor.
The insufficiently creative is initially characterized as “so mechanical or routine.” Mechanical and routine are understood in their ordinary discourse senses, as a conjunction or as connected by AND, and as the central clause. Subsequent clauses amplify the senses of mechanical and routine without disturbing their conjunction.
The delineation of the absence of a modicum of creativity can be correlated with classic conceptions of computability. The insufficiently creative can then be understood as a routine selection, coordination, or arrangement produced by an automatic mechanical procedure or algorithm. An understanding of a modicum of creativity and of copyright law is also indicated.
The value of the exegesis and interpretation is identified as its final simplicity, clarity, comprehensiveness, and potential practical utility.