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991.
Zheng Liu Mingqin Xuan Zhaohui Zhao Yufeng Cong Kejian Liao 《Petroleum Science and Technology》2003,21(7):1317-1325
In this article, the compatibilities between different components of a base asphalt and styrene butadiene styrene (SBS) have been analyzed from microscopic structures. Specifically, the asphalt was separated into three components: saturates, aromatics, and resins, by Solvent Recycled Absorption Chromatography Separation Technology (SRACST). The compatibilities between these different components and the polymer were compared with the help of Fluorescence Microscope (FM) with which the existing state of the polymer SBS in these different components could be examined obviously. The modified effects indicated that aromatics could cause SBS swollen and, resins dissolved SBS better than saturates, though both the two components could partially dissolve SBS and the two mixtures presented two immiscible phase systems. In order to further investigate the compatibility between aromatics and SBS, from macroscopic properties, an additive rich in aromatics was added to the SBS/asphalt mixture, and the result was satisfactory. 相似文献
992.
硫含量对钴钼型耐硫脱氧剂的脱氧活性影响 总被引:2,自引:0,他引:2
研究了工艺气中硫含量对钴钼型耐硫脱氧剂脱氧活性的影响。通过常压微反 -色谱装置测定脱氧剂的本征脱氧活性 ,加压原粒度反应器测定脱氧剂的表观脱氧活性 ,结合实际经验确定了耐硫脱氧剂所需的最低硫含量。还讨论了温度、压力、空速对耐硫脱氧剂脱氧活性的影响。结果表明 ,耐硫脱氧剂完全能满足耐硫变换工艺的要求 ,而且有耐硫变换的作用 ,并对耐硫变换催化剂起到保护作用 相似文献
993.
Piezoelectric Nanogenerators for Self-Powered Nanodevices 总被引:1,自引:0,他引:1
A novel approach converts nanoscale mechanical energy into electric energy for self-powering nanodevices.In our own work, we've used piezoelectric zinc-oxide nanowire (ZnO NW) arrays to demonstrate a novel approach for converting nanoscale mechanical energy into electric energy. Here, we review the fundamental principle behind the nanogenerator, present an approach for improving its performance, and discuss some of the challenges we face in pushing this technology to reach its potential. 相似文献
994.
995.
In this paper, a new dynamic developable surface model is proposed. The proposed model represents developable surfaces using triangle meshes. A novel algorithm is proposed to introduce the Hamilton principle into these meshes such that the resulting developable model is dynamic, i.e., it can offer a time-dependent continuous path to deform the model. Applications with examples are presented; these show that the proposed technique can model buckled developable surfaces well, and can offer physically-realistic animations of deformed developable surfaces. 相似文献
996.
Wei Fen Zhang Xi Guang Chen Pi Wu Li Cheng Sheng Liu Qiang Zhi He 《Drying Technology》2008,26(1):108-115
Three kinds of carboxymethyl chitosan/β-cyclodextrin microspheres loaded with theophylline were prepared by spray drying intended for pulmonary delivery. Mucociliotoxicity, permeation rate, and drug release characteristics of the product were investigated. The microspheres obtained by spray drying were found to be spherical with smooth or wrinkled surfaces. The mean particle size was between 3.39 and 6.06 µm. The microspheres demonstrated high product yield (43.7-50.2%), high drug loading (13.7-38.1%), and high encapsulation efficiency (86.9-92.8%). FT-IR indicated that there were interactions of theophylline with carboxymethyl chitosan matrix. Further studies on mucociliotoxicity and permeation confirmed that microspheres had better adaptability and high permeation rate. In vitro drug release from the microspheres was not related to the drug/polymer ratios. 相似文献
997.
Flammability ranking of foliage species by factor analysis of physical and chemical pyric properties
In this paper, factor analysis is introduced to evaluate the flammability of 55 foliage species that may be used in China for construction of the fuel break network of forest strips with lower flammability. Six pyric parameters, i.e. air dry moisture content, absolute dry moisture content, ignition point, ash content, caloric value and extractive content, are measured and used as variables for factor analysis. The covariance analysis shows that four principal factors can be extracted to reflect the flammability in different physical and chemical senses. In terms of the contributions of the four factors to the variances and the physical significance of the relevant parameters, the four factors are, respectively, termed as ‘flaming factor,’ ‘air dry factor,’ ‘ash factor’ and ‘absolute dry factor.’ The stability of the factor analysis method is examined by a different number of samples considered, and the variation degrees of the orderings indicate that the method has high reliability to measure the total flammability of foliage species. The results of the flammability evaluation are verified by comparison with the recommended tree species in the Chinese technology standard. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
998.
Hydrothermal Synthesis of Magnesium Aluminate Platelets 总被引:1,自引:0,他引:1
Zhi-Zhan Chen Er-Wei Shi Hua-Wei Zhang Yong Zhang Xiang-Biao Li Xue-Chao Liu Bing Xiao 《Journal of the American Ceramic Society》2006,89(12):3635-3637
Magnesium aluminate (MgAl2 O4 ) platelets were first synthesized by hydrothermal treatment of γ-AlO(OH) in a magnesium nitrate aqueous solution at 400°C. The platelets are 100–200 nm in width and 25 nm in thickness. The influence of temperature, the anions of the magnesium salt, the amount of magnesium salt, and precursor pH on the formation of such structure was investigated. The experimental results indicated that the anions of the magnesium salt and precursor pH could have a significant influence on the growth of MgAl2 O4 . MgAl2 O4 formation followed the in situ transformation mechanism, which was the reason why the MgAl2 O4 crystallites had a platelet morphology. 相似文献
999.
帅洼钼多金属矿,经过前期地质勘查工作,证明矿体严格受构造裂隙控制,为裂隙充填型脉状矿床。圈出的矿体规模小,矿石品位较低,工业意义不大。通过对前人地质成果的综合分析研究,认为在化学异常内带深部应有隐伏斑岩体存在,区内极为发育的断裂构造只是斑岩体上部的放射性裂隙,进一步地质勘查工作应建立在斑岩型成矿理论的基础上。 相似文献
1000.
近两年来,中央通过多种政策支持广大农村的社会主义新农村建设,东部发达地区发展较快,中西部和革命老区发展较慢。促进农村发展, 相似文献