A Study on the Announcement Effect of Private Placement Failure and Its Influencing Factors

2006年起，定向增发已逐步发展成为我国证券市场重要的再融资方式，随着市场对定向增发的关注度的提高，定向增发的发行数量和发行规模也不断增长，尤其在2015年，定向增发呈现爆发式增长，随着发行数量的增加，定向增发失败的情况也逐渐增多，之前的学者主要关注定向增发预案公告日的公告效应，但较少关注定向增发失败公告前后的市场反应，因此本文对此进行了研究分析。 本文选取2015年-2017年6月，我国证券市场筹划定向增发失败的588个上市公司样本进行研究，并采用事件研究法，对样本在定向增发失败公告日前后的[-10，10]的事件窗口期内的价格波动情况进行统计分析，通过计算样本的平均超额收益率和平均累计超额...Since 2006, private placement has gradually become an important way of refinancing in China’s securities market, and as the market pays a closer attention to private placement, the number and scale of issuance also keeps on the rise, and especially, private placement takes on an explosive growth in 2015. With the increase of the number of issuance, there is also an increasing number of cases of pr...学位：经济学硕士院系专业：经济学院_金融硕士学号：1562015115288

等离子体射流及其发生器研究进展

等离子体射流是近年来学术界兴起的新型研究领域。文中阐述了等离子体射流的基本概念和分类以及其技术优势,并从电极结构和驱动电源分类上重点介绍了国内外等离子体射流发生器的研究现状和前景展望。福建省自然科学基金资助项目(2010J01014

肾透明细胞癌差异表达基因的筛选及其核心基因相应miRNA和lncRNA预测分析

【目的】筛选肾透明细胞癌(ccRCC)中差异表达基因并其相关miRNA和lncRNA,寻找可作为ccRCC诊断及治疗的生物标志物。【方法】通过从TCGA数据库和GEO数据库筛选ccRCC差异表达基因并取交集,对差异表达基因进行GO功能分析和KEGG通路富集分析,使用MCODE软件筛选出差异表达基因中的核心基因,并利用mirDIP数据库和STARBASE数据库对核心基因上游的miRNA和lncRNA进行预测。【结果】共筛选出427个差异表达基因,这些差异表达基因在GO功能分析上主要与催化活性、受体活性和细胞黏附分子活性等功能相关,KEGG信号通路富集结果则表明其主要与PPAR、Rap1以及细胞因子受体相互作用等信号通路相关。从这些差异表达基因中筛选出11个核心基因,并预测到134个相应miRNA,接着对5个与ccRCC总体生存率相关的miRNA在STARBASE中共预测到6个相应lncRNA。最后将lncRNA、miRNA、核心基因以及相应信号通路在CYTOSCAPE中构建出一个互作网络。【结论】利用生物信息学技术将TCGA数据库与GEO数据库结合起来,筛选出ccRCC中差异表达基因,并对其中的核心基因进行miRNA与lncRNA预测分析,为后续找到可用于ccRCC临床诊断的靶标与治疗的靶点提供了有力帮助。国家自然科学基金(81570748);;福州总医院杰出青年培养专项(2017Q05

Seismic performance of RC composite shear walls with different steel embedded layout

超高层结构底部的钢筋混凝土剪力墙承受较大的轴力、弯矩和剪力,强震作用下易发生剪切或压溃破坏,通常采用钢-混凝土组合剪力墙以提高结构的抗震性能。以当前实际工程中常用的内置钢板组合剪力墙和内藏钢桁架剪力墙为研究对象,针对典型的剪力墙构件建立数值分析模型,对比了不同配钢形式剪力墙的滞回特性、承载力和耗能特性。研究表明:在相同含钢率的情况下,与提高构件配筋率的传统方法相比,钢板组合剪力墙和钢桁架剪力墙均能显著提高构件的承载力和耗能能力,改善剪切破坏模式。将配钢集中布置在剪力墙塑性铰区域时,钢板组合剪力墙的承载力和耗能能力明显优于钢桁架组合剪力墙。Reinforced concrete( RC) shear walls located on the bottom zone of the ultra-high-rise buildings are subjected to large axial load,shear force and moment,and the shear failure or crushing of concrete usually occurs during severe earthquakes.The seismic performance of such structures is improved by steel-concrete composite shear walls generally.Two typical composite shear walls commonly used in practice construction,steel plate-reinforced concrete composite shear walls( SPRCW) and steel concealed truss-reinforced concrete composite shear walls( STRCW),were studied in the paper.The numerical analytical models were developed to investigate the influence of typical shear walls with different steel layout on hysteretic response,carrying capacity and energy dissipation on.The results indicate that SPRCW and STRCW can clearly increase carrying capacity and energy dissipation,and reduce the likehood of shear failure model compared to the conventionally RC wall with the same steel ratio.When the steel concentrated in plastic hinge region of shear wall,the carrying capacity and energy dissipation of SPRCW are significantly better than STRCW.国家科技支撑计划课题(2012BAJ13B02); 中央高校基本科研业务费专项资金资助课

肾透明细胞癌Caki-1细胞系差异表达基因的生物信息学分析

目的比较肾透明细胞癌Caki-1细胞系与正常肾上皮细胞系ASE-5063中的差异表达基因(DEGs),寻找潜在的肾透明细胞癌特异性分子标志物。方法利用GEO数据库自带的GEO2R在线分析工具分析基因芯片GSE78179,将筛选出的DEGs分别导入Metascape、STRING以及Cytoscape进行综合分析并筛选出核心基因。最后使用Fun Rich等软件对筛选出的核心基因进行GO和KEGG富集分析。结果共筛选出562个DEGs,其中上调基因345个,下调基因217个。进一步使用MCODE筛选出36个关键基因,GO功能分析发现这些基因与细胞粘附分子活性、趋化因子活性、细胞通讯和信号转导等密切相关;KEGG通路富集结果则表明差异基因主要集中在趋化因子信号通路、TNF信号通路以及NF-κB信号通路等多种与肿瘤相关的通路上。结论运用生物信息学方法筛选出肾透明细胞癌Caki-1细胞系中DEGs,其中数个核心基因广泛参与多种肿瘤的病理进程,但尚未在肾透明细胞癌有相关研究报道,提示其可能是治疗肾透明细胞癌的潜在靶点。国家自然科学基金(81570748);;福州总医院杰出青年培养专项(2017Q05

Green Emission from a Strain-Modulated InGaN Active Layer

Strain-induced quantum dots (QDs) like island formations are demonstrated to effectively suppress pits/dislocation generation in high indium content (26.8%) InGaN active layers. In addition to the strain redistribution in the QD-like islands, strain modulation on the InGaN active layers by using the GaN island capping is employed to form an increased surface potential barrier around the dislocation cores, which inhibits the carrier transport to the surrounding dislocations. Cathodoluminescence shows distinct double-peak emissions at 503 nm and 444 nm, corresponding to the In-rich QD-like emission and the normal quantum well emission, respectively. The QD-like emission becomes dominated in photoluminescence due to the carrier localization effect of In-rich InGaN QDs at relatively low "carrier injection current". Accordingly, green emission may be enhanced by the following origins: (1) reduction in pits/dislocations density, (2) carrier localization and strain reduction in QDs, (3) strain modulation by GaN island capping, (4) enhanced light extraction with faceted GaN islands on the surface.National Natural Science Foundation of China [60876008, 61076091]; Program for New Century Excellent Talents in Fujian Province Universit

不同覆盖方式对新疆棉田土壤温度和水分的影响

土壤温度和水分是棉花生长的重要环境因子,通过测定不同覆盖下土壤温度的变化发现,覆膜对土壤的增温效应主要表现在棉花生长前期,5月份不同程度的覆膜可使土壤温度增加0.9~2.3℃,秸秆覆盖土壤温度比无覆盖情况低3.6~6.5℃。土壤温度最大日变幅与深度可拟合成对数函数关系,且两者间有很好的相关性。在整个观测过程中秸秆和地膜覆盖对土壤都有很好的保水作用,窄膜、宽膜、全膜以及秸秆覆盖条件下土壤含水量较之裸露地可分别提高0.15%~5.01%,0.19%~5.26%,1.34%~7.71%和0.47%~4.55%。但是,覆盖秸秆在棉花的生长过程中对株高几乎没有提高作用,而不同面积的覆膜对棉花株高均有显著的促进作用

Wide Area Communication and Synchronization Technology of Distribution Network Based on WIA

通信网络与信号同步技术对智能配电网的发展起到至关重要的作用,配电网规模庞大、结构复杂,终端接入数量多,现有技术手段已经无法满足配电网通信全覆盖与信号精确同步的需求。本文针对配电网的弱通信环境,提出了一种基于无线工业自动化(wireless industrial automation,WIA)技术的配电网广域通信与同步技术,对通信网络和同步系统的架构进行了详细的介绍,实验结果表明,WIA技术与现有电力通信资源相结合,能够有效解决采集盲点、网络覆盖能力不足等问题,并且能够为配电网量测系统提供精准同步手段