萨拉文化中心,谢莱夫特奥,瑞典

谢莱夫特奥市位于瑞典北部的北极圈内,有着悠久的木制建筑传统.这一传统构成了萨拉文化中心在项目国际竞争中脱颖而出的主要设计灵感,其口号是肩并肩.新的文化中心由市政府发起,被视作使谢莱夫特奥成为一个更有吸引力的地区的关键驱动力.建筑的选址和内容设计都通过市民对话向民众公布,公众还被邀请对国际建筑竞赛中的提案进行投票和评论,其意见形成总结供评委会参考.     

“钟乳石”竹亭装置——第16届威尼斯国际建筑双年展，自由空间

“钟乳石”竹亭是一个自由开放、人人平等共享交流的社交空间。这是一个面向公众的自由开放空间，由于这种社区感的营造需求，这个自由空间必须容易建造且具备结构简易、造价低的特点。在这个空间中，竹子作为唯一的材料。竹子的灵活性超越了其结构本身的意义，它创造了一个与阳光、风、大海等大自然之美紧密相连的空间。作为一个交流空间，这个构筑不仅能在威尼斯复刻搭建，也能在其他城市和乡村区域进行推广建造。     

排气量的无级调节

一、前 言 本文讨论了一种用于往复压缩机排气量无级调节系统的设计与改进问题。与一般按恒定差值改变排气量的分级调节系统不同,这个系统的调节量是不受限定的,因此是无级的,排气量能控制在恰与所需的气体量相适应。此无级系统是在部分压缩行程中用液压使吸气阀保持开启,使得一些已经吸入到气缸里的气体又被排回吸入管。当解除液压开始进行压缩时,排气量可以从0到 10O％任意调节。液压分配器受曲轴控制,在吸气阀正常打开以后,它加压于吸气阀卸荷器。另一套装置检查和指示排气压力或排气量,并通过一个定位器推迟或提前解除作用在吸气阀卸荷器上的液压,从而将压缩机排气量调整到完全合乎需要。     

OMA为中国电视巨擎CCTV设计新总部大楼

中央电视台的55.3万平方米的新总部大楼将出现在北京新的中央商务区建造的首批300座高层建筑之中。总建设成本估计约为6亿欧元(约48亿人民币)。该工程是为2008年的北京奥运会建设的。 中央电视台新总部大楼将是在中国建设的首批欧洲式的摩天楼之一。作为由北京国际招标公司组织的一项国际建筑竞标的结果,大都会建筑事务所(Officefor Metropolitan Architecture,OMA)提出的方案于2002年12月20日被授予合同。     

Two-dimensional localization with a single diffuse ultrasound field excitation

Traditional ultrasound imaging methods rely on the bandwidth and center frequency of transduction to achieve axial and radial image resolution, respectively. In this study, a new modality for spatially localizing scattering targets in a two-dimensional field is presented. In this method, the bandwidth of field excitation is high, and the center frequency is lowered such that the corresponding wavelengths are substantially larger than the target profiles. Furthermore, full two-dimensional field measurements are obtained with single send-receive sequences, demonstrating a substantial simplification of the traditional scanning techniques. Field reconstruction is based on temporal-spectral cross-correlations between measured backscatter data and a library of region of interest (ROI) backscatter data measured a priori. The transducer design is based upon a wedge-shaped geometry, which was shown to yield spatially frequency-separated bandwidths of up to 156% with center frequencies of 1.38 MHz. Initial results with these send-and-receive transducer parameters and cylindrical reflection targets in a 10-mm x 10-mm ROI demonstrate two-dimensional target localization to within 0.5 mm. Spatial localization of point scatterers is demonstrated for single and multiple scattering sites.     

The role of nitric oxide on matrix metalloproteinase 2 (MMP2) and MMP9 in placenta and fetus from diabetic rats

Matrix metalloproteinases (MMPs) play an important role in tissue remodeling that accompanies the rapid growth, differentiation, and structural changes of the placenta and several fetal organs. In the present study, we investigated whether the diabetic maternal environment may alter the regulatory homeostasis exerted by nitric oxide (NO) on MMPs activity in the feto-placental unit from rats at midgestation. We found that NADPH-diaphorase activity, which reflects the distribution and activity of NO synthases (NOS), was increased in both placenta and fetuses from diabetic rats when compared with controls. In addition, while a NO donor enhanced MMP2 and MMP9 activities, a NOS inhibitor reduced these activities in the maternal side of the placenta from control rats. This regulatory effect of NO was only observed on MMP9 in the diabetic group. On the other hand, the NO donor did not modify MMP2 and MMP9 activities, while the NOS inhibitor reduced MMP9 activity in the fetal side of both control and diabetic placentas. In the fetuses, MMP2 was enhanced by the NO donor and reduced by the NO inhibitor in both fetuses from control and diabetic rats. Overall, this study demonstrates that NO is able to modulate the activation of MMPs in the feto-placental unit, and provides supportive evidence that increased NOS activity leads to NO overproduction in the feto-placental unit from diabetic rats, an alteration closely related to the observed MMPs dysregulation that may have profound implications in the formation and function of the placenta and the fetal organs.     

Building blocks for integrated graphene circuits

The observation of single sheets of graphite (graphene) presents new possibilities for carbon-based nanoelectronics. We report defect tolerant configurations for a nearly reflectionless 120 degrees turn and nearly reflectionless symmetric and asymmetric splitters, which can be cut from graphene. Connections between zigzag strips of different widths can be made with either low or high reflectance depending on the connection shape.     

Graphene nanostrip digital memory device

In equilibrium, graphene nanostrips, with hydrogens sp2-bonded to carbons along their zigzag edges, are expected to exhibit a spin-polarized ground state. However, in the presence of a ballistic current, we find that there exists a voltage range over which both spin-polarized and spin-unpolarized nanostrip states are stable. These states can represent a bit in a binary memory device that could be switched through the applied bias and read by measuring the current through the nanostrip.     

法国中央理工高等电力学院,萨克雷,法国

在一个私有化的时代,城市正面临着重大的挑战:对公共领域的投资越来越依赖私人资产.由于这种对集体协议的重组,建筑的作用往往局限于只注重形状和表面的视觉影响,而缺乏对新的教育、社会和公民层面的贡献.巴黎中央理工学院发起的新工程学校设计竞赛成为探索如何应对这一严峻挑战的绝佳机会.     

山谷音乐厅

北京以北,一座半室外的音乐厅,如同一块来自远古的巨石,降落在拥有明长城遗迹的山谷. 音乐厅包含一个顶部开洞的半露天剧场、一个朝向草坡的室外舞台和面向长城的观景平台,既可以承载室内乐、音乐节、话剧、舞蹈等不同形式的专业演出,也可用于独处沉思或社区聚会.它彻底突破了音乐厅建筑的固有类型,从声音出发,由内而外地塑造建筑,成为浩然天地间的一处庇护所,建立人与自然的深层连接.