摘要：通过对115个旅游官方微博发布的194个有奖转发活动进行内容分析和编码,从而解构了活动微博的内容结构特征,并基于此构建回归方程分析了旅游官方微博短期营销活动绩效的影响因素。研究结果表明,活动绩效主要是受到官方微博粉丝基数、活动奖励和持续时间的影响,而活动任务要求的影响作用则十分有限,微博中对于品牌曝光的次数并没能产生显著的影响。依此为旅游官方微博短期营销活动的开展和活动微博的设计提出建议。

摘要：研制25WZ1-12型自吸旋涡泵试验样机,通过型式及变转速外特性试验,得出旋涡泵qv-H、qv-η性能曲线变化规律,验证qv-H、qv-P曲线换算满足相似理论比例定律,qv-NPSH曲线换算不满足汽蚀相似定律;用5孔管束探针对流道流场进行测量,得到流场静压ps、当量径向速度vre和当量圆周速度vue随泵转速变化分布状况;通过对试验数据的分析,解释了外特性参数与内部流动参数之间的联系和变化规律,指出旋涡泵的汽蚀类型及发生部位,为旋涡泵优化设计和建立内部流动模型提供参考依据。

摘要：本节内容选自人教版义务课程标准实验教科书八年级(下册)一、教学设计

摘要：A new three-layer hot-wall horizontal flow metal-organic chemical vapor deposition （MOCVD） reactor is proposed. When the susceptor is heated, the temperature of the wall over the susceptor also increases to the same temperature. Furthermore, the flowing speed of the top layer is also increased by up to four times that of the bottom layer. Both methods effectively decrease the convection and make most of the metal organic （MO） gas and the reactive gas distribute at the bottom surface of the reactor. By selecting appropriate shapes, sizes, nozzles array, and heating area of the walls, the source gases are kept in a laminar flow state. Results of the numeric simulation indicate that the nitrogen is a good carrier to reduce the diffusion among the precursors before arriving at the substrate, which leads to the reduction ofpre-reaction. To get a good comparison with the conventional MOCVD horizontal reactor, the two-layer horizontal MOCVD reactor is also investigated. The results indicate that a two- layer reactor cannot control the gas flow effectively when its size and shape are the same as that of the three-layer reactor, so that the concentration distributions of the source gases in the susceptor surface are much more uniform in the new design than those in the conventional one.

摘要：为解决现阶段文本情感摘要方法缺乏的问题，提出一种基于改进情感关键句抽取的情感摘要生成技术。利用 TF‐IS F抽取文章的关键词，分析句子包含关键词数量，采用情感词典对句子进行情感程度分析，通过余弦相似度考察句子与主题的相关性，实现情感关键句的抽取并应用到情感摘要中。实验结果表明，该技术考虑了句子中的关键词属性、情感属性以及主题相关性，能够提高情感摘要的准确率。

摘要：目的制备酮洛芬缓释微球,降低其不良反应。方法采用乳化溶剂扩散法制备酮洛芬缓释微球,通过正交设计试验优化处方,并对所制备微球的粒径分布、收率、包封率及体外释放度进行研究。结果制备的微球分散性良好,粒径分布集中在20～80μm之间,收率为73.3%,包封率为91.0%。结论该微球制备工艺较简单,体外释放实验表明酮洛芬微球有一定的缓释特性。

摘要：重组PCR是通过DNA重叠序列的衔接作用,使多个DNA分子融合在一起的体外扩增技术。它使基因全序列的拼接、基因融合、基因破坏及启动子交换等DNA操作变得简单易行。如今重组PCR已成为DNA分析的有效利器。本研究通过重组PCR在分子进化、基因敲除及基因敲入、启动子研究和转基因植物转化载体的构建等方面的实际应用,分析了该技术的影响因素,并针对引物设计、DNA碱基重叠长度、温度参数等重要反应条件提出了优化方案。