纯粹几何·古典精神——从格拉斯舒特住宅到三号住宅

对于大多数中国人来讲，奥斯瓦尔德·马蒂亚斯·翁格斯这个名字并不为人熟知，但在德国和欧洲地区，他是德国战后最重要的建筑师，也是德国新理性主义思潮的领军人物。其多产的一生为世人留下了大量伟大的建筑作品，他的创作思想深深影响了一大批欧洲建筑师。翁格斯的大多喜欢运用立方体等几何形体作为造型语汇，作品强调基于数字比例的严谨秩序，追求简化到极致的纯净形式，他的几所自宅尤其是后来的格拉斯舒特住宅和三号住宅都是他个人设计思想的最好体现。文章通过对格拉斯舒特住宅及三号住宅的对比分析，阐述了翁格斯追求纯粹几何形体的造型手法以及基于严谨数字比例的生成机制，探讨了背后蕴含的场所意义以及原型思想和古典精神。     

A simple transmit diversity system for fading channels using shaped sinusoidal functions

This paper proposes a transmit-diversity system using a pair of orthogonal pulses. The system uses a set of orthonormal-basic functions, which contains four shaped-sinusoidal pulses with the same frequency. The first two elements in the set are shaped sine and cosine pulses. The second two elements are the same sine and cosine pulses but they are shaped with the Hilbert transform of the shaping pulse of the first two elements. The modulator in the proposed system produces two modulated symbols for each data symbol. It uses the first two elements in the proposed set in modulating the first modulated symbol and the second two elements in modulating the second modulated symbol. The modulated symbols are transmitted though two antennas. The diversity order of the proposed system is twice the number of antennas in the receiver. In the proposed system, no space-time coding is used and the channel gains change every symbol period. This is different from the Multiple-Input-Multiple-Output (MIMO) system. The receiver of the proposed system consists of two matched filters for each receiving antenna. No special detectors or interference cancelation techniques are used because there is no interference between the outputs of the matched filters.     

Room-temperature synthesis of nanocrystalline titanium dioxide via electrochemical anodization

This paper presents a study of the growth of nanoporous anatase and rutile phases of titanium dioxide (TiO₂) subjected to electrochemical anodization at room temperature without post-thermal treatment, using sulfuric acid as the electrolyte. Effects of the applied voltage on the morphological, structural, and photoelectrochemical (PEC) properties were examined. Images from field emission scanning electron microscopy reveal that pore size could be manipulated by changing the anodization voltage. In addition, X-ray diffraction (XRD) results indicate that anatase and rutile phases of TiO₂ appeared in samples subjected to minimum anodization voltages of 100 V and 150 V. The Scherrer method was used to calculate the mean crystallite size, and the interplanar d-spacing formula was used to obtain the in-plane and out-of-plane strains. XRD measurements reveal that the amount of anatase and rutile crystallinity and their mean crystallite sizes were affected significantly by the anodization voltage. Results of the PEC studies reveal that the photocurrent density and photoconversion efficiency increased with increasing anodization voltage. In addition, the synthesized nanoporous TiO₂ showed stable photoresponse where only a small decay of photocurrent density is observed in numerous on-to-off illumination cycles.     

高校网络中心机房升级改造中UPS的设计策略

在高校信息网络中心机房升级改造中,不间断电源系统的规划应结合实际,兼顾可靠性和有用性的基础上,充分考虑冗余性、可管理性、可扩展性、可维护性、节能环保等基本要素,合理设计不间断电源系统配置,达到降低投资成本,提高系统的可靠性,减少能源消耗量的目标。     

Flight model performance test results of a helium dewar for the soft X-ray spectrometer onboard ASTRO-H

ASTRO-H is a Japanese X-ray astronomy satellite, scheduled to be launched in fiscal year 2015. The mission includes a soft X-ray spectrometer instrument (SXS), which contains an X-ray micro calorimeter operating at 50 mK by using an adiabatic demagnetization refrigerator (ADR). The heat sink of the ADR is superfluid liquid helium below 1.3 K. The required lifetime of the superfluid helium is 3 years or more. In order to realize this lifetime, we have improved the thermal performance from the engineering model (EM) while maintaining the mechanical performance. Then, we have performed a thermal test of the flight model (FM). The results were that the heat load to the helium tank was reduced to below 0.8 mW in the FM from 1.2 mW in the EM. Therefore, the lifetime of the superfluid helium is more than 3 years with 30 L of liquid helium.In this paper, the thermal design and thermal test results are described.     

Development of a spring analogue approach for the study of pillars and shafts

In civil and mining operations that involve ground excavation and support, the loads are distributed between the ground and support depending on their relative stiffness. This paper presents the development of conceptual single-degree-of-freedom models, which are used to derive equations for estimating displacements and stresses for ground-support interaction problems encountered in pillars in room-andpillar mining(natural support system), and liners for circular vertical shafts(artificial support systems).For pillar assessment, mine-pillar interaction curves can be constructed using a double spring analogy.Additionally, the effectiveness of different support systems can be evaluated depending on their effect upon the mine-pillar system. For shaft design, an initial estimation of the required lining strength and thickness can be readily made based on a double ring analogue. For both problems, the results from the proposed approach compare well with those obtained by finite element numerical simulations.     

Development of an experimentally validated semi-empirical fully-coupled performance model of a PEM electrolysis cell with a 3-D structured porous transport layer

A semi-empirical non-isothermal model incorporating coupled momentum, heat and mass transport phenomena for predicting the performance of a proton exchange membrane (PEM) water electrolysis cell operating without flow channels is presented. Model input parameters such as electro-kinetics properties and mean pore size of the porous transport layer (PTL) were determined by rotating disc electrode and capillary flow porometry, respectively. This is the first report of a semi-empirical fully coupled model which allows one to quantify and investigate the effect of the gas phase and bubble coverage on PEM cell performance up to very high current densities of about 5 A/cm². The mass transport effects are discussed in terms of the operating conditions, design parameters and the microstructure of the PTL. The results show that, the operating temperature and pressure, and the inlet water flowrate and thickness of the PTL are the critical parameters for mitigating mass transport limitation at high current densities. The model presented here can serve as a tool for further development and scale-up effort in the area of PEM water electrolysis, and provide insight during the design stage.     

Heaven on Earth

‘By 2050 we will have probed the universe even further, peeling back time as we strive for some sense of creation and meaning.’ The world's first neurologist in space, Roberta L Bondar , who conducted international experiments on space mission STS 42 and has subsequently undertaken neurological research with NASA, urges us to look up and into space, which is set to remain a rich area of exploration, scientific investigation and wonder, with the discovery of new planets, light, patterns and materials on the not-so-distant horizon.     

Global Village Media: Coming Together in the Early 1970s at Whiz Bang Quick City

Felicity D Scott , Associate Professor of Architecture at Columbia University Graduate School of Architecture, Planning and Preservation (GSAPP), describes here the instant city events of the early 1970s. These foreshadowed current global village media practices in what now seems a quaintly material manner: communication between sites involved the physical mailing of videotapes and ‘wire photos’ through the postal service. The sites themselves – in the US and elsewhere – were transformed into ‘instant cities’ through the erection of physical geodesic domes, teepees and inflatables in seas of mud. The true antecedents of today's instant networking, these pioneers embraced the newest technology available at the time and the most innovative forms of temporary architecture.     

中国最后的穴居部落——贵州中洞村的空间情感性

在中洞与洞外新建建筑之间,当地居民毅然选择前者,不关乎便捷、不关乎经济、不关乎利益,而紧紧简单的关乎情感。人们在使用空间的同时进行着情感的交流,因为空间的情感性而获得真实的喜怒哀乐,不能产生情感交流的空间是失落空间。在中洞生活多年的居民,不舍的便是中洞空间的情感性。文章试图以区位选址、聚落布局、建筑单体三级构架,结合人文历史、生活习俗等方面,就贵州格凸河风景区中洞村的空间情感性展开论述。