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991.
992.
Ahenk Yılmaz 《Color research and application》2017,42(3):378-387
Abstract: This article explores the effects of using black on spatial experience by means of phenomenological analysis of its architectural examples with a special focus on Serpentine Gallery Pavilion designed by Peter Zumthor. Contrary to the growing interest in the color in contemporary architecture, black rarely found a place in architectural history and in studies on color design. Whereas, the distinct achromatic qualities of the color that appear highly self‐contradictory swinging back and forth from absence to presence cover a wide range of potentials to be used in architectural design. Through insights delved into the spatial experience constructed around these qualities, this paper attempts to analyze how black is used as a design element in built environments. This analysis revolves around Zumthor s pavilion, which stood as a uniform black box on the expanse of green grass of London Kensington Gardens for more than three months in 2011. Encompassing various oppositions, the box built to surround a hortus conclusus, an enclosed garden inside, provided its visitors with a unique spatial experience depending predominantly on the combination of its form, tectonics and the qualities of its color, black. The phenomenological analysis of these qualities manifests that the architect utilized the contradictory characteristics of the color intentionally in order to create a complex and manifold spatial experience for visitors in and outside the box. In an interplay of absence and presence, momentary crystallizations of the vision of black provide architects with uncharted opportunities for creative use of color in the design of built environments. © 2016 Wiley Periodicals, Inc. Col Res Appl, 42, 378–387, 2017 相似文献
993.
Magnetic nanofluid actuation by rotating magnetic fields was proposed as a high‐performance tool for liquid mixing with enhanced micromixing features. A comparative study was conducted to evaluate the mixing index in T‐type mixers of magnetic and nonmagnetic fluids subject to static (SMF), oscillating (OMF), and rotating (RMF) magnetic fields. RMF excitation unveiled superior mixing indices with strong dependences to magnetic field frequency and content of magnetic nanoparticles. The impact of magnetic field types on micromixing was further examined at low and moderate Re numbers using the Villermaux–Dushman reaction and IEM micromixing model. The IEM‐inferred micromixing times were remarkably shorter by nearly four orders of magnitude in comparison with OMF and SMF excitations, and without magnetic field. The proposed mixing strategy is foreseen to complement innovative microfluidic devices with valuable mixing tools and methods for the diagnosis of the coupling between transport and intrinsic kinetics. © 2016 American Institute of Chemical Engineers AIChE J, 63: 337–346, 2017 相似文献
994.
在内径为Φ286 mm的无序环流混合器装置中,研究了无序环流混合器的流体力学特性和颗粒混合特性。以催化裂化(FCC)平衡剂为颗粒相,在中心区表观气速为0.3~0.5 m/s,边壁区表观气速为0.1 m/s,系统循环强度为0.25~1.00 kg/s的操作条件下,采用PV-6D型颗粒速度密度测量仪测量了混合器内床层各截面密度,并给出不同操作条件下的截面不均匀指数(RNI);采用热颗粒示踪技术给出了混合器内各测量截面的无因次温度分布,并引入混合指数用来定量描述不同操作条件下的颗粒混合程度,同时对比了传统环流混合器与无序环流混合器的混合能力。结果表明,无序环流混合器内部床层密度呈现中心低,边壁高的分布模式。随着循环强度的增加,RNI先减小后增大,随着表观气速的增加,RNI增大。预混合区混合指数为0.7~0.9,在高循环量,低中心区表观气速条件下(G_s为1.00 kg/s,u_(gd)为0.3 m/s),下料管进料影响区的截面混合指数低于其他操作条件。另外,无序环流混合器混合能力优于传统环流混合器。 相似文献
995.
采用氟烯烃与丙烯酸酯共聚的方法合成了氟含量(质量分数)分别为20%,35%的氟碳树脂,采用含氟丙烯酸酯直接共聚的方法合成了氟含量为50%的氟碳树脂。采用傅里叶变换红外光谱分析氟含量为20%和35%的氟碳树脂结构,结果表明合成的这两种氟碳树脂中含有氟基团;采用椭偏仪测试了树脂的折射率,结果表明3种氟碳树脂的折射率均低于丙烯酸树脂,氟含量为20%和35%的氟碳树脂的折射率相差不大,而氟含量为50%的氟碳树脂的折射率相对较高;采用X射线光电子能谱仪分析了3种氟碳树脂涂覆膜正反面的氟元素分布情况,结果表明随着氟含量的增加,膜正面氟含量逐渐增加至饱和,继续增加氟含量只会增加膜反面的氟含量;最后分别测试了树脂的抗污性能和附着力,结果表明氟含量为20%及35%的氟碳树脂在具有较低折射率的同时兼具良好的附着力及抗污性能。 相似文献
996.
从对力化学反应器挤出成型和剪切效果有重要影响的机筒螺槽深度(简称槽深)和机筒与螺棱间隙着手,分别通过改变机筒槽深和机筒与螺棱间隙,采用Polyfl ow软件对聚乙烯熔体在等温状态下的挤出过程进行数值模拟。对表征力化学反应器剪切效果的参数指标,如最大剪切速率、最大剪切应力和最大混合指数作相应的比较分析。研究结果表明,机筒未开槽(槽深0 mm)或槽深过大(2 mm)均降低了力化学反应器对物料的剪切和混合作用,而槽深为1 mm时,获得的最大剪切速率、最大剪切应力值和最大混合指数最大;随着机筒与螺棱间隙从0.5 mm依次增加到1 mm和2 mm,力化学反应器对物料的剪切及混合能力依次减弱,当机筒槽深为1 mm,且机筒和螺棱的间隙尺寸为0.5 mm时力化学反应器对物料的剪切和混合效果最好。 相似文献
997.
通过热氧老化评估了不同抗氧剂对尼龙6(PA6)耐黄变性能的影响,优选一组效果较好的抗氧剂作为基础抗氧剂配方。通过QUV 340 nm加速老化实验,分别评估了添加不同光稳定剂的PA6样品老化后其色差(△E)、黄色指数变化值(△YI)及拉伸强度保留率随时间的变化情况;通过长期热氧老化实验分别评估了样品在不同温度下,其△E、△YI及拉伸强度保留率随时间的变化情况。结果表明:Sunox508/Sunox626抗氧体系中加入光稳定剂会降低抗氧剂效果,其中加入Sunovin 5524/Sunovin 770影响最小。 相似文献
998.
Gang Chen Yantao Xu Haitao Guo Xiaoxia Cui Pengfei Wang Min Lu Xusheng Xiao Quan Guo Bo Peng 《Journal of the American Ceramic Society》2017,100(7):2914-2920
The Faraday effects of Ge‐Ga‐Sb(In)‐S serial chalcogenide glasses were investigated at the wavelengths of 635, 808, 980, and 1319 nm, respectively. The compositional dependences were analyzed and associated influencing factors including the absorption edge, the concentration of Sb3+/In3+ ions, and the wavelength dispersion of refraction index were discussed. 80GeS2·20Sb2S3 composition glass was found to have the largest Verdet constant (V=0.253, 0.219, 0.149, and 0.065 min·G?1·cm?1 for wavelengths 635, 808, 980, and 1319 nm, respectively) in these glasses, which is larger than that of commercial diamagnetic glasses (Schott, SF 6, V=0.069 min·G?1·cm?1@633 nm, for example). Sb3+ ions with high polarizability possessing s2‐sp electron jumps involving 1S0→1P1, 3P0,1,2 transitions are responsible for large Verdet constant, and Becquerel rule is proved to be an effective guidance for estimating the Verdet constant and further optimizing the compositions in chalcogenide glasses. 相似文献
999.
Spurious regression analysis in panel data when the time series are cross section dependent is analysed in the article. We show that consistent estimation of the long‐run average parameter is possible once we control for cross section dependence using cross section averages in the spirit of the common correlated effects approach proposed by Pesaran. This result is used to design a panel cointegration test statistic accounting for cross section dependence. The performance of the proposal is investigated in comparison with factor‐based methods to control for cross section dependence when strong, semi‐weak and weak cross section dependence may be present. 相似文献
1000.