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21.
PC/ABS合金研究进展 总被引:6,自引:0,他引:6
概述了PC/ABS合金国内外的开发应用现状,并综述了国内外近年来对PC/ABS合金的研究进展,其中包括:PC/ABS合金的相容性技术、相容剂的选用及影响合金性能的因素:原料、组分的配比、成型条件等,并对该合金的发展方向作了简要的分析,认为PC/ABS合金的开发研究在国内塑料合金的工业开发、应用中极其重要,开发的核心是相容化技术。 相似文献
22.
Mesoporous sulfated Al2O3–ZrO2 (MSAZ) catalysts with large surface areas and pore volumes after calcination at high temperature (650 °C) and with higher
Al2O3 content than 20wt% were successfully prepared from a template of block copolymer (P84). The MSAZ catalysts were characterized
by X-ray diffraction (XRD), N2 adsorption, transmission electron microscopy (TEM), 27Al magic-angle spinning nuclear magnetic resonance (MAS NMR), thermogravimetric analysis (TG–DTG), temperature-programmed
desorption of ammonia (NH3-TPD) and infrared spectra (IR) of adsorbed pyridine. It is shown that the resulting mesostructured sulfated Al2O3–ZrO2 samples have a well-developed textural mesoporosity. The number of acid sites present on MSAZ catalysts is higher than that
on conventional sulfated zirconia, and the former catalysts are more active than the latter one for various acid-catalyzed
reactions. 相似文献
23.
24.
ABSTRACT In this research, the effect of particle size on the surface oxidation and flotation behavior of galena in the lime system was studied. Coarse (?0.074 + 0.038 mm), intermediate (?0.038 + 0.025 mm) and fine (?0.025 mm) galena particles were used in the experiment. The dissolution tests, flotation tests, and sorption tests were accomplished. Through further analysis by XPS, the effect of particle size and lime was observed. The decrease of mineral particle sizes increased the adsorption ratio of collector and the dissolution of galena, while the hydrophilic product OH?/Ca(OH)+ produced by dissolution occupied the dominant position, which led to the minerals hydrophilic. 相似文献
25.
26.
New parameters, light transmission rate and minimum light transmissions, are proposed. These two parameters reflect the characteristics of the membrane‐forming system and the formation process of the membranes by phase inversion. The relationship between the light transmission and the porous structure of the membrane can be explained by the geometrical optics principles. Variation of the two parameters combining Reuvers's phase separation theory provided a convenient analytical method to predict effectively membrane morphologies. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 174–181, 2003 相似文献
27.
隧道式锚碇的变形破坏机制涉及到结构与围岩的协同作用问题。以华丽高速公路金安金沙江悬索桥两岸隧道锚变形破坏机制为研究对象,利用工程类比法评价了其稳定性控制要素,设计了超载数值试验。根据塑性区的扩展过程确定了施工安全监测和需要采取预加固的重点部位,确定了隧道锚围岩的破坏模式。根据锚面监测点位移由mm到cm量级突变确定的两岸锚岩系统极限荷载均为6~8倍设计缆力,则锚岩系统的设计承载力取3倍设计缆力下变形安全是有保障的。丽江岸塑性区在10 P下贯通;华坪岸塑性区在14 P下贯通。设计缆力作用下,丽江岸锚碇最大位移1.5 mm、围岩1.2 mm、地表0.5 mm;华坪岸锚碇最大位移1.7 mm、围岩1.5 mm、地表0.7 mm,其响应顺序为后锚面监测点前锚面监测点锚碇中间岩体地表点,可作为后期结构及围岩安全监测布点和预警的参考,也证明当前设计缆力下变形和强度均是安全的。 相似文献
28.
De-Long Zhang Ping-Rang Hua Edwin Yue-Bun Pun Guei-Gu Siu 《Journal of the American Ceramic Society》2007,90(9):2893-2899
Vapor transport equilibration (VTE) treatments were performed on a Y-cut bulk Er (1.6 mol%)-doped congruent LiNbO3 crystal and an X-cut pure congruent crystal, on one surface of which a 40 nm-thick film of erbium metal was coated before the VTE treatment. Scanning electron microscope, powder or single-crystal X-ray diffraction (XRD), polarized infrared absorption/emission of Er3+ as well as micro-Raman spectroscopy were used to study the two VTE crystals. The results are discussed in comparison with a corresponding as-grown bulk Er-doped crystal, calcined ErNbO4 powder, and a locally Er-doped congruent LiNbO3 crystal prepared by using the standard Er-diffusion technique. The experimental results show that the VTE treatment induces the formation of micrometer-sized ErNbO4 precipitates with the crystallographic morphology of a flat polyhedron not only on the surfaces of both crystals but also in the bulk of the homogeneously Er-doped one. The optical absorption and emission studies show that the formation of the precipitates results in substantial spectral changes in both the 0.98 and 1.5 μm regions. The micro-Raman studies allow to resolve four additional Raman peaks around 800 cm−1 in the E(TO) spectra of the two VTE crystals. These additional Raman peaks are associated with the characteristic vibrations with respect to the NbO4 3− group. Characteristic XRD, optical absorption, and emission and Raman peaks for identifying the ErNbO4 phase are proposed. Finally, the formation mechanism and light-scattering effect of the precipitates are discussed. 相似文献
29.
Lijin Xie Junfeng Ma Jun Zhou Zhongqiang Zhao Hua Tian Yonggang Wang Jiantao Tao Xiaoyi Zhu 《Journal of the American Ceramic Society》2006,89(5):1717-1720
Well-crystallized bismuth tungstate (Bi2 WO6 ) powders with different morphologies were successfully synthesized via a low-temperature molten salt method. The powders were characterized by X-ray diffraction, transmission electron microscopy, and UV-Vis, respectively. It was found that the variation of morphology of the obtained Bi2 WO6 powder mainly depends on the different reaction temperatures and the weight ratio of LiNO3 –NaNO3 salt to precursor. In addition, the UV-Visible absorption spectra showed that the synthesized powders had strong light absorption properties not only in the ultraviolet light but also in the visible light region. 相似文献
30.
论文分析了S/PDIF音频数据流的特点,引入模式识别中的训练机对S/PDIF音频数据流进行现场脉冲宽度特征提取。依据训练机结果建立分类器实现脉冲宽度分类,根据脉冲宽度进行同步前置码和逻辑电平的解码。利用硬件描述语言Verilog进行设计实现与验证,仿真结果说明这种特征提取方法可以提高S/PDIF接收机数据解译码的适应性和准确性。 相似文献