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991.
曹勇  龙小柱  李长久  毕颖 《辽宁化工》2004,33(11):627-628,664
对焦化柴油的不安定因素进行了研究.通过研究发现,焦化柴油中的酸性物质、碱性物质、微量金属及可见光均是影响焦化柴油安定性的因素,空气对焦化柴油的安定性影响较小.  相似文献   
992.
研究了硫酸盐-柠檬酸体系电镀锌-镍合金工艺。该锌-镍合金作为印制板用压延铜箔的阻挡层。考察了镀液主要成分及工艺条件对压延铜箔性能的影响,并对各因素进行分析,由此确定了压延铜箔电镀锌-镍合金工艺条件。经测试,使用该工艺处理的压延铜箔与印制板基板具有良好的结合力,并具有较强的耐腐蚀性。  相似文献   
993.
研究了镀液中硝酸银浓度、石墨粉加入量和阴极电流密度等工艺条件对镀银石墨粉含银量和电镀效果的影响。用扫描电镜对镀银石墨粉的微观形貌和镀覆效果进行分析,通过X射线衍射仪对镀银石墨粉高温灼烧后的剩余物进行分析测试并计算镀银石墨粉的含银量。研究结果表明:采用惰性电极作为电镀阳极,在化学镀预处理过的石墨粉表面可成功镀覆一层银,其含银量达76%。  相似文献   
994.
This study investigates perceived risk and trust in relationship to the Diffusion of Innovation Theory [Rogers, E.M., 1962. Diffusion of innovations. Glencoe, IL: The Free Press; 1983. Diffusion of innovations. 3rd ed. New York: The Free Press] from a cultural perspective to understand the determinants of behavioural intent to adopt mobile commerce among the Y Generation in Kazakhstan. Surveys from 345 university-level students and subsequent structural equation modelling revealed perceived risk, trustworthiness and Rogers’ five innovation characteristics are important determinants. Perceived risk and trustworthiness are important determinants because of the high uncertainty avoidance characteristics of the Kazakh society. This study advances theory regarding culture- and generation-based characteristics to transition economies by verifying theoretical proposition regarding the behavioural intent towards mobile commerce adoption, resulting in a greater understanding of mobile commerce adoption among the Y Generation in transition economies. Marketing implications are discussed.  相似文献   
995.
Unsaturated polyester (UP)/montmorillonite (MMT) nanocomposite was prepared by using hydroxypropylacrylate (HPA) as a reactive diluent instead of conventional styrene monomer and the effect of polarity of reactive diluent on properties of nanocomposite was investigated. X‐ray and mechanical test data indicated that mixing for an extended period of time is essential to enhance the physical properties of nanocomposites in the UP/Cloisite 6A system. This was attributed to the high polarity of HPA that may disturb the preintercalation of UP resin into the galleries of MMT. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 238–242, 2004  相似文献   
996.
The tensile properties of polypropylene (PP) filled with hollow glass beads have been measured at room temperature to identify the effects of the particle contents, size and its distribution on them in the present article. The mean diameters of the fillers were 11, 35, and 70 μm, and they were named as TK10, TK35, and TK70 respectively. The surface of these particles was pretreated with silane coupling agent. The results showed that the yield stress (σy) decreased gently for PP/TK70 systems, whereas decreased relatively obviously for PP/TK35 systems with increasing the volume fraction (?f) of the fillers. When ?f was less than 5%, the tensile strength at break (σb) of the composites increased with the increase of ?f. When ?f was more than 5%, σb was almost a constant for PP/TK70 systems, while σb decreased linearly for PP/TK35 systems. The tensile fracture strain (εb) of the composites decreased suddenly when ?f was less than 5%, and then decreased slightly with increasing ?f. When ?f was 10%, σy and σb increased while εb decreased with the increase of the bead diameter. Furthermore, the σy was predicted by means an equation proposed in the previous work, and good interfacial adhesion was shown between the hollow glass beads and the matrix. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1697–1701, 2007  相似文献   
997.
Natural objects often contain vivid color distribution with wide variety of colors. Conventional colorization techniques, on the other hand, produce colors that are relatively flat with little color variation. In this paper, we introduce a randomized algorithm which considers not only the value of target color but also the distribution of target color. In essence, our algorithm paints a color distribution to a region which synthesizes color distribution of a natural object. Our approach models the correlation between intensity and color in HSV color space in terms of H – S, H – V and S – V joint histogram. During the colorization process, we randomly swap and reassign color of a pixel to minimize a cost function that measures color consistency to its neighborhood and intensity‐to‐color correlation captured in the joint histogram. We tested our algorithm extensively on many natural objects and our user study confirms that our results are more vivid and natural compared to results from previous techniques.  相似文献   
998.
Different poly(methyl methacrylate/n‐butyl acrylate)/poly(n‐butyl acrylate/methyl methacrylate) [P(BA/MMA)/P(MMA/BA)] and poly(n‐butyl acrylate/methyl methacrylate)/polystyrene [P(BA/MMA)/PSt] core‐shell structured latexes were prepared by emulsifier‐free emulsion polymerization in the presence of hydrophilic monomer 3‐allyloxy‐2‐hydroxyl‐propanesulfonic salt (AHPS). The particle morphologies of the final latexes and dynamic mechanical properties of the copolymers from final latexes were investigated in detail. With the addition of AHPS, a latex of stable and high‐solid content (60 wt %) was prepared. The diameters of the latex particles are ~0.26 μm for the P(BA/MMA)/P(MMA/BA) system and 0.22–0.24 μm for the P(BA/MMA)/PSt system. All copolymers from the final latexes are two‐phase structure polymers, shown as two glass transition temperatures (Tgs) on dynamic mechanical analysis spectra. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3078–3084, 2002  相似文献   
999.
Image calibration requires both linearization of pixel values and scaling so that values in the image correspond to real‐world luminances. In this paper we focus on the latter and rather than rely on camera characterization, we calibrate images by analysing their content and metadata, obviating the need for expensive measuring devices or modeling of lens and camera combinations. Our analysis correlates sky pixel values to luminances that would be expected based on geographical metadata. Combined with high dynamic range (HDR) imaging, which gives us linear pixel data, our algorithm allows us to find absolute luminance values for each pixel—effectively turning digital cameras into absolute light meters. To validate our algorithm we have collected and annotated a calibrated set of HDR images and compared our estimation with several other approaches, showing that our approach is able to more accurately recover absolute luminance. We discuss various applications and demonstrate the utility of our method in the context of calibrated color appearance reproduction and lighting design.  相似文献   
1000.
Light refracted by a dispersive interface leads to beautifully colored patterns that can be rendered faithfully with spectral Monte‐Carlo methods. Regrettably, results often suffer from chromatic noise or banding, requiring high sampling rates and large amounts of memory compared to renderers operating in some trichromatic color space. Addressing this issue, we introduce spectral ray differentials, which describe the change of light direction with respect to changes in the spectrum. In analogy with the classic ray and photon differentials, this information can be used for filtering in the spectral domain. Effectiveness of our approach is demonstrated by filtering for offline spectral light and path tracing as well as for an interactive GPU photon mapper based on splatting. Our results show considerably less chromatic noise and spatial aliasing while retaining good visual similarity to reference solutions with negligible overhead in the order of milliseconds.  相似文献   
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