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991.
Qiang Yuan Wei Jiang Lijia An R. K. Y. Li 《Journal of Polymer Science.Polymer Physics》2005,43(3):306-313
The effects of glass bead (GB) size and annealing temperature on the formation of β‐crystals of glass bead‐filled polypropylene (PP) are studied in this articles. Differential scanning calorimetry (DSC) measurements indicated that the amount of β‐form in PP crystals was a function of the glass bead content and size. For a fixed glass bead content, it was found that the smaller the diameter of the glass bead, the higher was the content of β‐crystals formed in the PP. On the other hand, wide‐angle X‐ray diffraction (WAXD) measurements revealed that the annealing temperature was also a major factor that affected the crystallization behavior of glass bead‐filled PP. It seemed that the blends with different glass bead contents had their own optimal annealing temperatures for β‐crystal formation. As an example, when the glass bead content was 48 wt %, the optimal annealing temperature for β‐crystal formation was about 108 °C, whereas it shifted to 100 °C for 14 wt % glass bead‐filled polypropylene. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 306–313, 2005 相似文献
992.
周家馨 《中国科学B辑(英文版)》1990,(12)
The constraints on the variation in the ratios of pairs of trace elements during crystal fractionation are described by using a set of inequality functions. This approach to the interpretation of the variation in trace element ratios provides a more thorough basis for describing the quantitative relationships between the variation of trace element ratios during the fractional crystallization, the difference of the bulk distribution coefficients of the two elements and the degree of fractionation. The constraints imposed by the inequalities lead to certain consequences on the variation in the ratios of pairs of trace elements during crystal fractionation. For these consequences not yet recognized in literature detailed explanation will be given in the present paper. 相似文献
993.
Sim‐Siong Wong Sacide Alsoy Altinkaya Surya K. Mallapragada 《Journal of Polymer Science.Polymer Physics》2005,43(22):3191-3204
The effect of glassy skin formation on the drying of semicrystalline polymers was investigated with a comprehensive mathematical model developed for multicomponent systems. Polymers with high glass‐transition temperatures can become rubbery at room temperature under the influence of solvents. As the solvents are removed from the polymer, a glassy skin can form and continue to develop. The model takes into account the effects of diffusion‐induced polymer crystallization as well as glassy–rubbery transitions on the overall solvent content and polymer crystallinity. A Vrentas–Duda free‐volume‐based diffusion scheme and crystallization kinetics were used in our model. The polymer–solvent system chosen was a poly(vinyl alcohol) (PVA)–water–methanol system. The drying kinetics of PVA films were obtained by gravimetric methods with swollen films with known water/methanol concentrations. The overall drying behaviors of the polymer system determined by our model and experimental methods were compared and found to match well. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3191–3204, 2005 相似文献
994.
以SiCl4H2为气源,用等离子体增强化学气相沉积(PECVD)方法低温快速沉积多晶硅薄膜.实验发现,在多晶硅薄膜的生长过程中,气相空间各种活性基团的相对浓度是影响晶粒大小的重要因素,随功率、H2/SiCl4流量比的减小和反应室气压的增加,晶粒增大.而各种活性基团的相对浓度依赖于PECVD工艺参数,通过工艺参数的改变,分析生长过程中空间各种活性基团相对浓度的变化,指出“气相结晶”过程是晶粒长大的一个重要因素.
关键词:
气相结晶
多晶硅薄膜
晶粒生长
SiCl4 相似文献
995.
Ewa Jakubczyk 《Czechoslovak Journal of Physics》2002,52(2):171-174
The crystallization process of the metallic glass Fe28Ni50Si9B13 was investigated by DSC, Hall effect, electrical resistivity, and X-ray diffraction methods. It proceeds in two stages. Ni phase is formed at the temperature of 723 K and Ni3B phase at 773 K. The phase creation is accompanied by an abrupt decrease of the Hall and electrical resistivities and the spontaneous Hall coefficient. 相似文献
996.
997.
A dynamic phosphor-silicate glass (PSG) gettering method is proposed in which the processes of the gettering of Ni by PSC and the crystallizing of α-Si into poly-Si by Ni take place simultaneously. The effects of PSC gettering process on the performances of solution-based metal induced crystallized (S-MIC) poly-Si materials and their thin film transistors (TFTs) are discussed. The crystallization rate is much reduced due to the fact that the Ni as a medium source of crystallization is extracted by the PSC during crystallization at the same time. The boundary between two neighbouring grains in S-MIC poly-Si with PSG looks blurrier than without PSG. Compared with the TFTs made from S-MIC poly-Si without PSC gettering, the TFTs made with PSC gettering has a reduced gate induced leakage current. 相似文献
998.
999.
稀土掺杂BAP玻璃的制备及性能研究 总被引:3,自引:0,他引:3
采用UVPC和DSC等测试手段系统研究了稀土Sm2O3掺杂BaO-Al2O3-P2O5(BAP)激光防护玻璃的光谱性能及析晶性能。结果表明:吸收光谱的特征吸收峰强度随Sm2O3含量的增加逐步增强,吸收谱线向两端非均匀展宽,玻璃在1075nm波长处的光密度与稀土含量近似成线性关系,当Sm2O3含量达到17.5mol%时,透过率T<0.03%;随着稀土含量的增加,玻璃的析晶参数β先增后减,玻璃的析晶倾向也随之先下降而后提高,BaO/Al2O3比值的降低可使玻璃的形成能力提高。 相似文献
1000.
T.R. Bott 《Experimental Thermal and Fluid Science》1997,14(4):356-360
Crystallization fouling or scale formation is temperature dependent, and a degree of supersaturation is required before precipitation occurs. In general, a nucleus is necessary around which crystals can form. The mechanism of crystallization on surfaces is complex, and it is difficult to explain in mathematical terms, although attempts have been made. The paper concludes with a brief review of scale formation under boiling conditions and the deposition of wax crystals from organic liquids. 相似文献