Abstract During his fifty‐five year tenure, Prof. Barry M. Trost has made countless advancements in the fields of synthetic method development and complex molecule total synthesis. In addition to his well‐known contributions in the areas of allylic alkylation and transition metal‐catalyzed cycloisomerization reactions, Prof. Trost has developed many other useful synthetic methods as well. Although less prominent than some of his hallmark transformations, these reactions are no less significant and have enjoyed widespread adoption by the synthetic community. This review highlights many of these unsung processes – including several reduction/oxidation reactions, metal‐catalyzed alkene‐alkyne and alkyne‐alkyne couplings, phosphine‐catalyzed redox isomerizations, and methods for determining absolute stereochemistry – and their utility in the total synthesis of natural products, pharmaceuticals, and other complex bioactive molecules.
Abstract This investigation deals with the rocking response of rigid blocks subjected to earthquake ground motion. A numerical procedure and computer program are developed to solve the non‐linear equations of motion governing the rocking motion of rigid blocks on a rigid base subjected to horizontal and vertical ground motion. The response results presented show that the response of the block is very sensitive to small changes in its size and slenderness ratio and to the details of ground motion. Systematic trends are not apparent: The stability of a block subjected to a particular ground motion does not necessarily increase monotonically with increasing size or decreasing slenderness ratio. Overturning of a block by a ground motion of particular intensity does not imply that the block will necessarily overturn under the action of more intense ground motion. In contrast, systematic trends are observed when the problem is studied from a probabilistic point of view with the ground motion modelled as a random process. The probability of a block exceeding any response level, as well as the probability that a block overturns, increases with increase in ground motion intensity, increase in slenderness ratio of the block and decrease in its size. It is concluded that probabilistic estimates of the intensity of ground shaking may be obtained from its observed effects on monuments, minarets, tombstones and other similar objects provided suitable data in sufficient quantity is available, and the estimates are based on probabilistic analyses of the rocking response of rigid blocks, considering their non‐linear dynamic behaviour.
We report using Inverse Electromagnetic Design to computationally optimize optical antenna shapes. Optimized antennas deliver 10% of incident power to a 50×40×10 nm3 spot in a practical magnetic recording medium for Heat Assisted Magnetic Recording.
Chapter 6 develops the structure of the stress response in the presence of material constraints on the basis of the Lagrange-multiplier rule. Examples given include incompressibility and inextensibility. Further applications are examined in Problems. The concepts are presented in more detail than one usually finds in the text and monograph literatures.
Diferencias étnicas y diferencias sociales en las escuelas primarias de Nueva Caledonia. A partir de una encuesta realizada durante el año 1983, entre alumnos del curso medio del segundo año primario de la región de Nouméa, se muestra que el sistema de enseñanza primaria caledonio reproduce en su estructura como en su funcionamiento las principales discrepancias de la sociedad colonial. Los establecimientos de la capital se caracterizan, en efecto, no por su pluralidad étnica sino por una segregación étnica y de clase marcada de los escolares, inducida por la ecología de las relaciones sociales urbanas y reforzada por las migraciones escolares selectivas toleradas por la administración. La barrera de la edad, la acumulación diferencial de los fracasos y la desigualdad frente a la selección hacen que los niños de las etnias y de las camadas dominadas continuen a ser eliminados en masa incluso antes de llegar al colegio. Y hasta las ambiciones de los alumnos son estrechamente determinadas por su posición social y concurren a la conservación del orden escolar y social establecido. Se ve en éstas condiciones que es vano e ilusorio esperar de la escuela una reducción de las desigualdades capaz de concurrir a la democratización de la sociedad caledonia.
The modal pushover analysis (MPA) procedure is extended for analysis of reinforced concrete special moment resisting frame (RC-SMRF) buildings, after demonstrating that the theory, assumptions, and approximations underlying this procedure are valid for such systems. The principal extension of the procedure is in the hysteretic model for modal SDF systems, chosen as the peak-oriented model to represent the global monotonic and cyclic behavior of such buildings, characterized by deterioration of stiffness and strength under cyclic deformation. The median seismic demands for 4-, 8-, 12-, and 20-story RC-SMRF buildings—designed to comply with current codes—due to an ensemble of 78 ground motions scaled to four intensity levels were computed by MPA and nonlinear RHA, and compared. It is demonstrated that, even for the most intense ground motions that deform the buildings far into the inelastic range, the MPA procedure demonstrates an adequate degree of accuracy that should make it useful for practical application in estimating seismic demands for RC-SMRF buildings. In contrast the FEMA-356 force distributions are inadequate in estimating seismic demands for the 8-, 12-, and 20-story buildings at all excitation intensities, from the weakest that causes response essentially within the linearly elastic range, to the strongest that drives the buildings far into the inelastic range.
We report the observation of a current-driven metal (M)-insulator (I) phase oscillation in two-terminal devices incorporating individual WxV1-xO2 nanobeams connected to parallel shunt capacitors. The frequency of the phase oscillation reaches above 5 MHz for approximately 1 mum long devices. The M-I phase oscillation, which coincides with the charging/discharging of the capacitor, occurs through the axial drift of a single M-I domain wall driven by Joule heating and the Peltier effect.
It is found for the first time that a molecule can induce a displacive reconstruction in the substrate on which it is adsorbed. This is observed in a refined structure determination of Rh(111)(2\ifmmode\times\else\texttimes\fi{}2)-${\mathrm{C}}_{2}$${\mathrm{H}}_{3}$, in which ${\mathrm{C}}_{2}$${\mathrm{H}}_{3}$ (ethylidyne) is adsorbed on the Rh(111) single-crystal surface. This result strengthens an earlier hypothesis that catalytic reactions are usually accompanied by distortions in the catalyst, which can profoundly affect reaction rates and selectivities.
