快速Delaunay逐点插入网格生成算法

对插入形心的Delaunay逐点插入算法,提出按单元可插度分组的双向链表组数据结构,避免了对最大可插度单元的搜索。采用了邻接单元搜索、双向链表存储、随机方向搜索、邻接旋转、几何量继承等技术,使算法的计算时间与生成单元数近似呈线性关系,时间复杂度达到O(N1.05),N为生成单元数。算例表明,在一台AMD Athlon3200+(主频2.0 GHz)PC上,该算法的四面体单元生成速度达50 000个/s以上。

珍珠母的微结构与力学行为研究进展

珍珠母(nacre或mother-of-pearl)是软体动物贝壳内层的主要结构材料,具有优异的力学性能,已成为当前先进工程材料仿生设计和制备的研究热点.该生物材料具有完善的分级微结构,使其强度与韧性远高于组成这种材料的纯文石相.本文从珍珠母的微结构、实验研究以及力学模型3个方面对珍珠母的研究现状进行了概述,并指出目前研究中一些仍待解决的关键问题.

多孔和铸装高能推进剂的燃烧转爆轰

为研究多孔和铸装高能推进剂的危险性能，设计加工了燃烧转爆轰的实验装置，并建立了以光电管为主的测试系统。经实验发现，多孔装药在燃烧向爆轰的转变过程中有冲击波／爆轰波的回传现象，而铸装药则没有。

Caminos de Petrarca en la España del Siglo XV

[ES] Situar la fortuna hispánica de Petrarca en el contexto de su recepción europea contribuye a trazar un panorama más justo de su presencia en la España del siglo XV: ni la llegada de Petrarca a la Península es particularmente tardía, ni son excepcionales la manera superficial en la que se entendieron algunos de sus libros o la exigüidad de una lectura estrictamente humanística. La diversidad que se da dentro de su propia obra, así como el hecho de que desde muy temprano fuera utilizado como un clásico de la antigüedad, explica los distintos caminos por los que ejerció su influencia.

Edge and Size Effects in Micro Composite Structure

Because of the load transfer effect of interface layer, the stress distribution inside the composite structure of film/substrate can be very different from the Timoshenko's model. In this paper, we give the derivation and analysis of such load transfer effect of shear-lag (S-L) model. The micro-structure size (boundary conditions) effect together with interface load transfer effect becomes more and more important as the microstructure size including the three dimensions of thickness, width and length shrinks. The microstructure size is also responsible for the so-called edge-induced stress. The edge effect and difference of S-L model and Timoshenko model are also demonstrated.

The communicative dimension in the translation of the David Lodge's Nice work

Eguíluz, Federico; Merino, Raquel; Olsen, Vickie; Pajares, Eterio; Santamaría, José Miguel (eds.)

Asymmetric organocatalytic cascade reactions

302 p. : gráf.

A complex systems modelling approach for decentralized simulation of electrical microgrids

ICECCS 2010

Relatorios e synopses dos trabalhos da Camara dos Srs. Deputados : relativos ao anno de 1896 : acompanhados de differentes documentos : organisados na Secretaroa da mesma Camara

Sinopse dos trabalhos da Câmara dos Deputados, em 1896.

碎屑流沿坡面运动的数值模拟

根据Savage提出的碎屑流运动方程,分析了碎屑流沿坡面下滑过程中的运动特性,包括速度分布和高度分布的变化。重点考察了床面摩擦系数、土体内摩擦角、初始运动速度和坡角等因素对碎屑流运动形态的影响。研究表明,在不同的因素组合情况下,碎屑体的运动形态有明显的区别。土体内摩擦角和坡角对碎屑流的运动形态和最大运动距离影响明显。相对来说,床面摩擦角对碎屑流的最大运动距离影响不明显,这可能是因为床面摩擦只影响靠近床面的部分物质的运动。

饱和岩石剪切失稳后效分析

剪切载荷下的饱和岩石,在初始阶段出现几条细的剪切带,最后均形成一条剪切带。为了分析这个现象,将饱和岩石中剪切带的发展分为多阶段的过程进行分析,针对几个有限幅值扰动下剪切带的演化进行研究,获得了剪切带从几个小的非均匀扰动演化为最后充分发展的剪切带的详细过程。结果表明,剪切带的发展由两个阶段组成:非均匀剪切过程和实际剪切带发展过程。

水平动载下粉土地基中桶形基础承载力离心机实验研究

对动载作用下分层土中单桶基础动承载特性、四桶基础动承载特性进行了离心机实验模拟。结果表明,桶顶与粘土面相同时,有上覆粘土层条件下的桶基动力响应较无上覆粘土层条件下的孔压增长小,但沉陷大;桶顶与粘土层下的砂土面相同时比与粘土面相同时的响应大。桶基在动载后的静承载力得到提高。由于液化区的滤波和对动载的衰减作用,发生沉降的范围有限,离桶壁约一倍桶高距离。超孔隙水压从桶基边沿水平向逐渐衰减,从土面开始往下逐渐衰减到零。桶基周围砂土完全液化的厚度随载荷幅值的增加而增加,最大值约为桶高的40%。

The effect of the incident relative phase on the four-wave mixing field and the electromagnetically induced transparency

In a A-type system employing a two-photon pump field, a four-wave mixing field can be generated simultaneously and, hence, a closed-loop system forms. We study theoretically the effect of the relative phase between the two incident fields on the generated four-wave mixing field and the electromagnetically induced transparency. It is found that the phase of the generated four-wave mixing field is the sum of the incident relative phase and a fixed phase that is irrelative to the incident relative phase. Hence, the total phase of the closed-loop system is independent of the incident relative phase. As a result, the incident relative phase has no effect on the electromagnetically induced transparency, which is different from the case of a A-type loop system closed by a third incident field. (c) 2005 Pleiades Publishing, Inc.