太阳能光伏技术在建筑中应用

本文从太阳能光伏技术应用的现实意义出发,介绍了光伏系统的组成及功能、光伏电池性能特点等,重点分析了光伏建筑一体化（BIPV）的应用特点、相关要求、建筑与结构的设计要点及发电量计算,阐述了光伏技术的应用现状及发展前景。     

车用质子交换膜燃料电池仿真技术路线

质子交换膜燃料电池作为燃料电池中重要的一种类型,可应用于汽车及小规模的发电站与便携式移动能源,是当前新能源领域的研究热点。主要针对车用质子交换膜燃料电池的三种仿真参数模型就当前国内外研究进展进行论述。     

Performance tuning and sparse traversal technique for a cell‐based fetch length algorithm on a GPU

For determining distances (fetch lengths) from points to polygons in a two‐dimensional Euclidean plane, cell‐based algorithms provide a simple and effective solution. They divide the input area into a grid of cells that cover the area. The objects are stored into the appropriate cells, and the resulting structure is used for solving the problem. When the input objects are distributed unevenly or the cell size is small, most of the cells may be empty. The representation is then called sparse. In the method proposed in this work, each cell contains information about its distance to the nonempty cells. It is then possible to skip over several empty cells at a time without memory accesses. A cell‐based fetch length algorithm is implemented on a graphics processing unit (GPU). Because control flow divergence reduces its performance, several methods to reduce the divergence are studied. While many of the explicit attempts turn out to be unsuccessful, sorting of the input data and sparse traversal are observed to greatly improve performance: compared with the initial GPU implementation, up to 45‐fold speedup is reached. The speed improvement is greatest when the map is very sparse and the points are given in a random order. Copyright © 2015 John Wiley & Sons, Ltd.     

Electrochemical conversion of switchgrass and poplar in molten carbonate direct carbon fuel cell

One way of sustaining fuel cell technology is using renewable and sustainable energy means provided by biomass. This article explores switchgrass and poplar in a molten carbonate electrolyte direct carbon fuel cell. It investigates their electrochemical conversions and provides results of power density, current density, open circuit voltage (OCV) and other parameters. The biomasses were pyrolysed at 800°C to produce carbon fuels. Biomass carbon fuels were mixed with molten carbonate and subjected to different operating conditions (600–800°C) in the fuel cell. The electrochemical performances of the poplar fuel were better than those experienced with switchgrass fuel. At 800°C the OCV of poplar fuel (1.08?V) has higher output than switchgrass (0.87?V). The peak power density recorded for poplar fuel was 23.91?mW/cm² while switchgrass fuel was lower at 21.60?mW/cm². Poplar fuel (81.53?mA/cm²) gave a maximum current density with switchgrass fuel lower at 74.00?mA/cm².     

Towards garden city wonderlands: new town planning in 1950s Taiwan

This article explores the historical context, process and result of introducing and implementing ‘new’ town planning in early post‐war Taiwan. The two so‐called ‘garden cities’ are examined: Jhong‐Sing New Village and Yonghe City, both of which were formulated in the mid‐1950s by the same group of local planners. It reveals that the assumed necessity of importing Western planning paradigms arose from the abrupt escalation of urban concentration caused by the late 1940s mass migrations from China. To cope with this unprecedented population growth, planning profession was swiftly established. The novice planners, in search of a reference for developing ‘new’ towns to decentralise excessive urbanisation, modelled their ‘new’ town planning on English suburban morphology. In the absence of an input of external expertise, the planners appeared to mistake aesthetic order and pastoral imagery of low‐density residential development in England as practically viable solutions to the pressing urban problems in Taiwan. In a false hope that adopting Western ideas and practices would quickly lead the island to a better world, Taiwan initiated the importation of planning paradigms. This planning transfer not only evidently manifests a mode of ‘borrowing’ in post‐colonial countries in international diffusion but also re‐articulates the disseminating nature of modern planning and the existence of one‐direction flows characterising the global dynamics of diffusion in the twentieth century.     

Cities as planning models

A key feature of modern planning history has been the identification of cities admired for their ‘good planning’. In varying degrees, they have stimulated emulation, selective or partial borrowing, or even direct copying of their admired planning features. Model cities at different phases of planning history include Paris, Frankfurt, Vienna, Moscow, London, Stockholm, Barcelona, Chicago, New York, Portland and Vancouver. In recent years, new models have emerged, such as Singapore or Curitiba. The article considers how such cities became or are becoming models. It examines the methods by which the knowledge and reputation of the ‘model’ are promoted and disseminated. The importance of key actors, and visits, conferences and exhibitions focused on planning issues are considered. So too are less specific factors which help draw the gaze of a wider world. The article also considers whether such cities were/are places where new planning approaches have been invented or where they were implemented on a larger scale. Overall the paper discusses a key and strengthening feature in the circulation of contemporary planning knowledge. It does not answer all the surrounding questions in any definitive sense but opens up new debates about planning and the processes behind its historical evolution.     

Miscibility enhancement of poly(vinyl chloride)/polystyrene blend: Application to membrane separation of benzene from benzene/cyclohexane mixture by pervaporation

In order to improve the miscibility of poly(vinyl chloride)/polystyrene (PVC/PS) system and to use the prepared material as a membrane to separate benzene from benzene/cyclohexane mixture by pervaporation technique, two poly(styrene-co-N-vinylpyrrolidone) (PSVP) copolymers containing 6.67 and 13.55 mol% of N-vinylpyrrolidone (N-VP) contents were synthesized through a radical polymerization. A comparative study of the miscibility of the PVC/PSVP blends with different compositions was carried out using differential scanning calorimetry, viscosimetry and Fourier transform infrared spectroscopy methods in which the interaction parameters between the two components were widely investigated. To improve the pervaporative flux of PVC membrane to separate benzene from benzene/cyclohexane mixture, a preliminary test of swelling and sorption was performed on PVC/PSVP7 membranes using an azeotropic benzene/cyclohexane mixture. It was revealed that the PVC/PSVP7 membrane containing 10 wt% of PSVP7 showed the best performance and the diffusion behaviour of this mixture through PVC and PVC/PCVP7 membranes has a Fickian behaviour. The pervaporation parameters of this membrane support those of the swelling and selective sorption data and reveal that this membrane could enhance the total flux without significantly affecting its selectivity to benzene.     

间位芳纶溶解及凝固性能研究

以二甲基乙酰胺(DMAc)、二甲基甲酰胺(DMF)、二甲基亚砜(DMSO)、1-甲基-2-吡咯烷酮(NMP)为溶剂,分别加入LiCl和CaCl_2制备溶解体系,研究了间位芳纶在这几种溶解体系中的溶解性能。再以H_2O-DMAc、H_2O-DMF、H_2O-DMSO、H_2O-NMP为凝固浴,研究了溶剂种类、芳纶溶液质量分数、离子浓度等对间位芳纶溶液的凝固性能的影响。结果显示:Li Cl-DMAc溶解体系具有更强的溶解性能;凝固值随凝固浴中凝固剂H_2O的含量的增加不断减小,而临界浓度几乎没有变化;随着凝固浴温度的增加,凝固值增大,临界浓度减小;凝固值随凝固浴中离子浓度的升高而增大,但临界质量分数则不断降低。另外,间位芳纶溶液的扩散系数随着凝固浴中H_2O的含量的减少不断减小,随着芳纶浓度的增加不断减小。     

Growth kinetics of WC-Fe layer formed at the surface iron during solid-phase diffusion

Tungsten carbide-reinforced iron-based surface composites were prepared via in situ solid-phase diffusion method; the variables included three temperatures (1085, 1100, and 1125 °C) and four heat treatment times (15, 45, 75, and 105 min). The samples were examined by X-ray diffraction, scanning electron microscopy, and Vickers hardness test. Results show that the tungsten carbide-reinforced iron-based surface composites consist of WC, α-Fe, W, and iron carbide phases, and the thickness of the WC-Fe layer ranges from 20.57±1.24 µm to 63.27±2.02 µm at 1085 °C. Furthermore, the maximum microhardness value of the WC-Fe layer at 1085 °C for 15 min is 2169 HV_0.1, whereas that of the iron matrix is 239 HV_0.1; such values demonstrate that the hardness of the composites are markedly enhanced. The kinetic of WC-Fe layer was analyzed by measuring the depth of pure WC layer as a function of heat treatment time and temperature. The results show a parabolic relationship between the thickness of pure WC layer and heat treatment time, and the activation energy for the pure WC layer was estimated to be 184.06 kJ mol⁻¹.