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Morphologies of precipitation phases along grain boundary of the as-cast Mg-6.0Zn-0.45Zr, Mg-6.0Zn-(1.2Y) and Mg-6.0Zn-0.6Zr-1.0Y alloys are studied by using the methodologies of metallurgical phase analysis, scanning electron microscopy(SEM) analysis and energy diffraction x-ray(EDX) analysis. The experimental result indicates that the main precipitation phases along grain boundary of the as-cast alloys Mg-6.0Zn-0.45Zr is Mg-Zn binary phase. There are two kinds of precipitation phases along grain boundary for Mg-6.0Zn-1.2Y and Mg-6.0Zn-(0.6)Zr-1.0Y alloys. One grew at triangular grain boundary, which is fish-bone -like and contained Mg-Zn binary phase and Mg-Zn-Y ternary phase. The other distributed mainly around the grain, which is net-like and contained Mg-Zn-Y ternary phase. In addition, there are lots of granular phases, extending to the interior of the grain, at the rim of grain boundary phases. Finally, Y can intensively change morphology of precipitation phases along grain boundary of the as-cast Mg-Zn-Zr alloy (ZK60) alloys. 相似文献
94.
《Journal of Cereal Science》2014,59(3):472-478
To study the role of abscisic acid (ABA) and gibberellin (GA) sensitivity in regulating pre-maturity α-amylase (PMA) in wheat grains, plants were grown in a glasshouse under cold-shock and ambient conditions. α-amylase activity in response to applied ABA and GA was measured in detached-grains with the embryo removed (in vitro) and in intact-grains attached to the plant (in situ). The in vitro experiment was conducted using Spark (low PMA-susceptible genotype) and Rialto (highly PMA-susceptible genotype), with the aim of defining the time point for GA-sensitivity. The results showed an increase in GA-sensitivity at about 640 degree days after anthesis (DAA) in Rialto. There was no evidence for a change in ABA-sensitivity in either variety. The in situ experiments were conducted using genotypes from a Spark × Rialto doubled haploid population segregating for the Rht-D1a (tall) or Rht-D1b allele and for the presence or absence of 1BS/1RS. For Rht-D1a (tall) or Rht-D1b genotypes with or without 1BS/1RS, the cold-shock significantly increased GA-sensitivity, whereas there was no significant change in ABA-sensitivity. These results show PMA is related to an increase in GA-sensitivity that occurs in the aleurone at around 640 degree DAA, and can be enhanced by environmental factors (e.g. cold-shock). 相似文献
95.
以氨基脲(SEM)和对醛基苯甲酸(CP)为原料合成半抗原(CP-SEM),将半抗原和载体蛋白偶联后免疫Balb/C小鼠,应用杂交瘤技术建立稳定分泌抗氨基脲的杂交瘤细胞株。常规制备腹水,用辛酸-硫酸铵法纯化,并对纯化的mAb进行特异性鉴定。通过对不同抗体组合的分析和条件的优化,建立检测氨基脲的间接竞争ELISA方法。利用对醛基苯甲酸衍生草鱼肌肉提取的氨基脲,用建立的ELISA方法进行检测,并计算回收率和最低检测限。经细胞融合、筛选及克隆化,共获得7株稳定分泌抗氨基脲的杂交瘤细胞株,其中4株亲和力较高。建立了间接竞争ELISA检测方法,该方法灵敏度达到0.1ng/mL,平均回收率为98.47%,在草鱼组织中的最低检测限为0.76ng/g,回收率为70.55-100.56%,可用于肌肉中氨基脲残留的检测。 相似文献
96.
以经秋水仙碱诱导获得的银杏大花粉为材料,以未经处理的正常银杏花粉为对照,利用扫描电子显微镜和激光扫描共聚焦显微镜分别观察2种花粉表面形态,并分析对比其细胞内的DNA相对荧光量与银杏大花粉核内染色体倍性关系,为正确检出银杏二倍体花粉奠定重要工作基础。研究结果表明,此方法用于花粉粒的倍性鉴定科学准确,所需试验样本少,实用性强,在植物花粉倍性鉴定中有着较好的应用前景。 相似文献
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The project problem because of wall rock’s deformation fracture in deep-buried and high geostress conditions is very prominent at Jinping hydropower Ⅱ station underground engineering. According to the characteristics of the bedded marble collected from Jinpiing Ⅱ hydropower station auxiliary traffic tunnel in deep-buried area, three-point bending experiment on different bedded direction specimens with SEM high temperature testing system is carried out to test the stress of bedded marble in different directions and the failure mechanism and deformation features of homogeneous marble. In the test, there are 3 groups of specimens, include parallel bedded specimen, vertical bedded specimen and homogeneous marble specimen. The results show that: bedded marble’s bedded feature is because of the banded structure feature between dolomite mineral particles and calcite mineral particles; the fracture mechanism and strength parameter of bedded marble depend on different force directions and mineral composition. Because of the cement capacity between dolomite minerals and particles size, homogeneous marble specimen has the lowest strength. The marble specimens’ deformation shows 3 stages, and because of different fracture mechanisms, the plastic deformation of parallel bedded specimens is more obvious than that of vertical bedded specimen. While the deformation of homogeneous marble can be divided into 2 stages, i.e. before and after peak stage, and the after peak stage shows the complete deformation development process. 相似文献
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