网络舆情及其应对与上市公司的信息效率

网络舆情的兴起给资本市场带来了深远影响,对监管层和上市公司的舆情管理工作也提出了新的挑战.借助于监管部门对深市上市公司网络舆情应对状况的调查,实证检验了网络舆情及其应对与上市公司的信息效率的关系.研究发现,网络舆情危机会造成当年度股价崩盘,且来自自媒体的转载会增大股价崩盘的幅度,网络舆情重视和应对程度良好的公司在面对舆情危机时的股价崩盘幅度更低.上市公司对网络舆情的重视及投入能够向资本市场传递公司特质信息,提高资本市场的信息效率,进而降低未来股价崩盘风险和股价同步性.结论表明,上市公司加强网络舆情应对并非是满足监管要求和投资者诉求的面子工程,而是一项切实有效的求是工作,结论对完善资本市场信息传播管理制度,提高资本市场信息效率具有一定的参考价值.     

Effects of Cr and Mo elements on the microstructures and compressive properties of the in situ (TiC_xN_y–TiB_2)/Ni cermets

In-situ(TiC_xN_y–TiB_2)/Ni cermets with 70 wt%TiC_xN_y–TiB_2 were successfully fabricated by combustion synthesis and hot pressing sintering in Ni-Ti-B_4C-BN powder systems.The microstructures,density,compressive properties,and hardness of the TiC_xN_y–TiB_2/Ni cermets with the addition of 0–8 wt%Cr/Mo to the Ni-Ti-B_4C-BN powder systems were compared and analysed.The results showed that the ceramic particles distributed uniformly in the cermets,and the size of the ceramic particles reduced with the Cr/Mo addition.Both Cr and Mo addition can improve the hardness,compressive properties,and fracture strains of the cermets.The hardness,compressive strength,and fracture strain of the(TiC_xN_y–TiB_2)/(Ni+Cr)cermets increased from 1561 HV,2.94 GPa,and 2.9%to 1864 HV,3.65 GPa,and 3.4%,respectively when the Cr content increased to 5 wt%.The hardness and compressive strength of the(TiC_xN_y–TiB_2)/(Ni+Mo)cermets increased from 1561 HV and 2.94 GPa to 1902 HV and 3.43 GPa,respectively when the Mo content increased to 8 wt%.The cermets with Cr had better compressive properties than the cermets with Mo.     

Taxonomy of the genus Tantunema Siddiqi, 1982 (Dorylaimida: Tylencholaimidae) with description of one new and two known species

One new and two known species of the genus Tantunema Siddiqi, 1982 are described and illustrated. Tantunema indicum sp. nov. is characterized by having a small body (length 0.32–0.45 mm); lip region cap-like, set off by slight constriction; odontostyle 6–7 µm and odontophore 8–10 µm long; pharyngeal expansion gradual, expanded part occupying about 35–41% of total neck length, lumen of posterior expanded part widened and thickened; female genital system mono-opisthodelphic, anterior genital branch absent; tail short, hemispheroid, 0.8–1.1 anal body diameter long. Tantunema pakistanense (Timm, 1964) comb. nov. (=Tylencholaimus pakistanensis Timm, 1964) and Tantunema intermedium (Peña-Santiago and Coomans, 1996) Andrássy, 2009 are redescribed. A diagnostic compendium and key to species of the genus is also provided.     

Underdetermined DOA estimation and blind separation of non-disjoint sources in time-frequency domain based on sparse representation method

This paper deals with the blind separation of nonstation-ary sources and direction-of-arrival （DOA） estimation in the under-determined case, when there are more sources than sensors. We assume the sources to be time-frequency （TF） disjoint to a certain extent. In particular, the number of sources presented at any TF neighborhood is strictly less than that of sensors. We can identify the real number of active sources and achieve separation in any TF neighborhood by the sparse representation method. Compared with the subspace-based algorithm under the same sparseness assumption, which suffers from the extra noise effect since it can-not estimate the true number of active sources, the proposed algorithm can estimate the number of active sources and their cor-responding TF values in any TF neighborhood simultaneously. An-other contribution of this paper is a new estimation procedure for the DOA of sources in the underdetermined case, which combines the TF sparseness of sources and the clustering technique. Sim-ulation results demonstrate the validity and high performance of the proposed algorithm in both blind source separation （BSS） and DOA estimation.     

《楝亭图咏·寄题楝亭二截句》与余怀的遗民情结

《楝亭图咏》为张伯驹旧藏,今存于国家图书馆.它是曹寅为彰显其父曹玺功德,广集名家追怀赞颂曹玺的画作、题诗、题文而成的册页.此册页纸色、纸质不一,后经改装成卷,现存四卷.著名文人余怀亦题诗二首.该诗不仅反映了余怀的思想和遗民情结,也是余怀研究的重要文献之一.     

实践展示教学法在体育教学中的应用研究

实践展示教学法作为一种在教育教学中较常用的教学方式,能够使原本抽象的动作印象变得生动直观,使学生方便容易理解.科学合理地运用实践教学法,通过体育运动技能的展示,可以使学生掌握体育运动技能的精髓,提高学习运动技能的效果,夯实基础.     

基于区间证据推理的不确定性航线配船方法

为弥补不确定性航线配船模拟算法的不足,提出一种基于区间证据推理的航线配船解析算法.该方法以证据推理理论为基础,以船舶公司期望效用最大化为目标,考虑航线特征及船舶属性等因素,构建出一个多航线、多船型的航线配船模型.与目前的模拟算法相比,该方法具有稳定性好、准确性高、可以处理模糊数据等优点.最后,通过算例验证了模型的可行性和方法的有效性.     

《算数之钥》中球形穹顶的测量法

中世纪中亚数学家阿尔·卡西在《算术之钥》中不但给出了5种伊斯兰建筑风格拱形门和球形穹顶的设计方案,而且用初等方法计算了其中拱形部分的表面积和体积,遗憾的是,他没有给出球形穹顶部分的表面积和体积的具体计算过程,只用文字叙述了用初等数学方法来计算其中第四类球形穹顶表面积和体积的基本思路,并直接给出了球形穹顶表面积和体积分别与其直径平方和直径立方之比的近似值.讨论了阿尔·卡西的初等算法,并用微积分方法来验证其算法的正确性,同时指出阿尔·卡西得到的数据与实际数据之间的误差.     

如何科学、合理地开展小学英语写作技能训练

作为一种重要的语言输出形式,小学生＂写作＂能力测试题目已被正式地列入小学升初中英语考试的试题中。为探讨科学、有效的写作技能训练方法,本文从小学英语写作技能训练的分阶段目标、教学原则和活动形式三个方面展开讨论,为小学英语教师以及英语教育专业的师范生提供行而有效的训练技巧以及适应面广、可操作性强的教学活动。     

家庭工作界面因素对情绪劳动的影响机制

为了研究服务型员工的家庭因素对其工作表现的影响,通过三个阶段的问卷调研,并运用SPSS和AMOS分析工具对调研结果进行分析.结果表明:服务员工家庭工作冲突会抑制情绪劳动中深层表演与真实表达;家庭工作增益会促进情绪劳动中深层表演与真实表达;家庭工作冲突对表层表演的正向影响会随着家庭工作平衡的增强而减弱;家庭工作增益对表层表演的负向影响、对深层表演的正向影响会随着家庭工作平衡的增强而增强.