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采用化学气相沉积的实验方法,以纯Zn粉为锌源,O_2为反应气,N_2为载气,在双管管式炉内制备了多脚结构的纳米ZnO,研究了载气流量对产物形貌和光致发光性能的影响;通过计算流体动力学软件FLUENT对实验条件下管式炉内O_2和Zn蒸汽的浓度分布进行了模拟。实验和模拟结果表明:随着N2流量的增大,O_2浓度减小,产物由钉状多脚结构向针状多脚结构转变;沉积位置处Zn蒸汽的浓度远大于O_2浓度,绿光发射峰主要是由ZnO纳米晶体氧空位引起的,沉积反应主要由O_2控制。 相似文献
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This study aimed to investigate the differential prospective relationships of social-oriented achievement motivation (SOAM) and individual-oriented achievement motivation (IOAM) with student's adoption of specific achievement goals and their affective wellbeing (AWB). A total of 332 Chinese university students (Mage = 19.139; Female = 75%) voluntarily participated in the baseline and the 1-year follow-up surveys of this study. The factor score path analysis results showed statistically significant positive paths from SOAM and IOAM at baseline to performance goals and mastery goals, respectively, at follow-up. Moreover, a statistically significant positive path was found from SOAM at baseline to negative affective experiences, at follow-up, and no association was found between IOAM and AWB, after controlling for achievement goals. The findings suggest the usefulness of raising educators' and parents' awareness regarding the double-edged sword of utilizing socially valued motives to promote performance approach goals in individuals because such values potentially lowering their psychological wellbeing. 相似文献
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张茂冲 《淮南职业技术学院学报》2005,5(1):58-60
就矿井双滚筒共同驱动带式输送机经常出现的滚筒磨损问题,通过对带式输送机双滚筒共同驱动方式下两滚筒牵引力分配的推导,探讨了两驱动滚筒实际直径偏差对牵引力配比的影响,并针对以上影响造成的双滚筒共同驱动带式输送机滚筒磨损问题,提出了解决方案及措施。 相似文献
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Aikaterini Vassiou Athanasios Mouratidis Eleni Andreou Konstantinos Kafetsios 《教育心理学》2016,36(5):879-897
Performance at school is affected not only by students’ achievement goals but also by emotional exchanges among classmates and their teacher. In this study, we investigated relationships between students’ achievement goals and emotion perception ability and class affect and performance. Participants were 949 Greek adolescent students in 49 classes and their Greek language and mathematics teachers. Results from multilevel analyses indicated that students’ mastery-approach and performance-approach goals were positively related to positive affect whereas performance-avoidance goals were negatively related to positive affect. At class-level, relationships between achievement goals and affect were moderated by students’ emotion perception ability. These findings highlight the importance of emotion abilities and their role in motivational processes for class-level outcomes. 相似文献
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Research in Higher Education - Do persons over age 62 enroll in universities to maintain their social interaction and stay in life's mainstream? This question was researched through a... 相似文献
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论述了Weibull分布下双应力交叉步加试验的时间折算公式及数据统计分析的逆矩估计法。 相似文献
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