361 research outputs found
A Study on the Operating Performance of Chinese Listed Companies with Primary Offerings of Seasoned Equity and Rights Offerings
我国上市公司通过证券市场进行直接融资的行为一直为市场所诟病,不少人通过资本结构、资金来源、融资成本、市场效应等各方面进行了研究。本文试图从另一个方面,即上市公司在融资前后的经营绩效表现,来研究上市公司的融资效果。本文共分为六章: 第一章简要地回顾了国内外关于增发的研究情况,将配股和增发的研究分为股价效应和业绩表现两类; 第二章对增发与配股进行了比较研究,介绍了增发和配股制度的历史沿革,并对两者进行了比较分析。 第三章是增发和配股存在的问题,分别介绍了增发和配股在实施中带来的问题和引起的争议。 第四章是研究设计,介绍了本文研究的问题,所使用的研究模型和研究方法,以及样本的选择和数据的来源...The behavior of direct financing of Chinese listed companies by securities market has always been criticized, and some researches have been done according to capital structure, financing resource, capital cost, market effect and so on. However, the paper will discuss the topic from the companies’ financial performance. The framework of the dissertation is as follow: Chapter 1 is a literature rev...学位:工商管理硕士院系专业:管理学院工商管理教育中心_工商管理硕士(MBA)学号:20011510
基于FBG传感技术的复合材料加筋板低速冲击损伤监测
针对碳纤维增强树脂基复合材料低速冲击损伤的实时监测,本文设计将布拉格光纤光栅(FBG)传感器埋植在复合材料加筋板结构的三角填充区,在线监测复合材料T型加筋板冲击损伤过程。分别将FBG传感器埋植于复合材料层合板内部和复合材料T型加筋板的三角填充区,对比FBG传感器的埋入对复合材料层合板与复合材料T型加筋板对力学性能的影响,结果表明内埋FBG传感器的复合材料层合板试样的拉伸强度比未埋植传感器的层合板试样降低了约5%,但在FBG传感器的破坏应变范围内,FBG传感器可以准确、实时地监测复合材料的应变信号。将FBG传感器埋入复合材料T型加筋板的三角填充区,内埋FBG传感器的加筋板样件压缩破坏载荷与未埋植的样件基本一致。通过对比加筋板蒙皮上冲击位置、冲击能量对FBG传感器测得的冲击过程持续时间和最大应变值的影响,表明冲击过程持续时间随着冲击能量增加而延长,最大应变值随着冲击距离的增加呈下降趋势,而最大应变值随着冲击能量的增加呈上升趋势。利用FBG传感器测得的应变信号可初步实现对复合材料T型加筋板蒙皮冲击损伤位置及冲击能量的实时监测。国家重点研发计划(2016YFD0700603);;航空科学基金(2016ZF68011);;江苏省重点研发计划(BE2015007);;福建省科技创新平台建设计划(2014H2006
Effects of Municipal Domestic Sewage Effluents on the Growth of Calendula officinalis
用三种稀释倍数的城市生活污水[污水∶清水(v/v)为1﹕0、1﹕0.5、1﹕1]处理金盏菊种子及盆花,结果表明,污灌处理不仅显著地降低种子的萌发率,还增加萌发后幼苗病害的发生率;未经稀释的原生污水显著抑制金盏菊幼苗的生长,而稀释后抑制作用降低,当稀释至适当浓度时,则对幼苗生长起促进作用;对于金盏菊成年植株,污灌处理(不论稀释与否)显著地增加其茎、叶和根的鲜重,分别较对照增加161.63%~215.12%、86.77%~109.23%和23.89%~34.13%。综合分析表明,原生污水经过适当稀释后用于草花污灌,可以使污水中的营养盐得到回用,提高草花的观赏性。The seeds and potted plants of Calendula officinalis were treated with municipal domestic sewage effluents. The treatments were divided into 4 groups according to effluents : tap water(v/v): I, 1 : 0; II, 1 : 0.5; III, 1 : 1; control, 0 : 1. Compared with the control, sewage irrigation treatments (I, II and III) obviously reduced the rate of seed germination and increased the disease incidence of seedlings. The undiluted raw sewage could remarkably restrain the seedling growth, and the retarding effect could be relaxed by diluting with tap water. Furthermore, the diluted sewage of proper concentration could improve the seedlings growth. Compared to the control, sewage irrigation treatments increased the fresh weight of the stem, leave and root of full-grown C. officinalis plant by 161.63 %~215.12 %, 86.77 %~109.23 % and 23.89 %~34.13 %, respectively. The results of this study showed that the diluted sewage could be reused in irrigation and the nutrient elements in the sewage effluents could increase the ornamental value of herbage flowers
Effect of the Construction of Green Belts on the Attenuation of Traffic Noise along the Urban Trunk Roads in Xiamen City
通过对厦门市主干道绿化带种类结构调查以及噪声测定等,分析了厦门市主干道绿化带结构及其减噪效果。结果表明,厦门市主干道绿化带可分为4种结构:单一乔木型、乔木+疏灌木/绿篱型、乔木+密灌木型以及乔木+小乔木+灌木/绿篱型,带宽多在4~10M。厦门市主干道绿化带总体减噪能力为0.93~12.96db,绿化带对交通噪声超标治理率达70%。绿化带减噪能力y(db)与带宽X(M)呈显著的线性关系:y=1.2251X+0.2416(r2=0.8603);绿化带的附加衰减与总衰减亦呈显著正相关:y=0.4535X+0.2698(r2=0.9242),噪声的附加衰减主要受绿化带结构的影响,上述四种结构对噪声附加衰减平均值分别达0.93、2.25、4.43和6.72db。绿化带的宽度和结构均是影响其减噪效果的关键因素。Through site investigation and noise monitoring, the effects of the construction of green belts along the urban trunk roads in Xiamen Island on the attenuation of noise has been studied.The results show that the construction of green belts along the trunk road can be divided into four kinds of types as bellows: type I, single arbor; type II, arbor + shrub; type III, arbor + sub-arbor and type Ⅳ, arbor + sub-arbor + shrub.Their width varied among 4--10 m.The noise-reducing ability (y, dB) of the green belts varied from 0.93 to 12.96 dB with various belt widths (x, m), and can be expressed as following: y=1.2251x+0.2416.Meanwhile the additive attenuation of traffic noise (y, dB) presents a closely linear relationship with the total noise-reducing ability (x, dB) as following: y=0.4535x+0.2698 (R2=0.9242).Meanwhile, the additive attenuation of traffic noise is main affected by the constructions of green belts, which reached 0.93, 2.25, 4.43 and 6.72 dB, respectively for the above four kinds of construction types.It shows that the width and construction of green belts play the same important role to reduce the traffic noise
Distribution pattern of PAHs in Jiulong River Estuary by both measurement and simulation
于2011年12月(冬季)在厦门九龙江河口及西港采集9个表层海水水样,采用固相萃取—气质联用方法(SPE-GC-MS)分析其中16种多环芳烃含量。研究结果表明,总溶解态态∑PAH含量为157.9~858.0 ng/L。在河口区,随着盐度升高,PAHs含量逐渐降低。基于比值法分析,表明厦门九龙江及西港海域海水中的PAHs来源存在多种途径,呈现混合来源的态势。利用LEVEL III逸度模型研究菲,芘和苯并(a)芘在各介质间的分布以及水——气界面的交换通量。模拟结果与本文实测和文献中的实测值相吻合。在16℃时,三种多环芳烃的大气沉降通量分别为17.38,7.86和8.38μg/day/m2。其中菲在大气沉降中占主导地位,约三分之二。三种多环芳烃的大气沉降通量均随温度升高而减少。当温度高于32℃时,苯并(a)芘开始从水体释放。The concentration of 16 polycyclic aromatic hydrocarbons( PAHs) of nine water samples,collected in the Jiulong River Estuary in December,2011,were analyzed using the SPE-GC-MS method. The results showed that the concentration range of total dissolved PAHs( ΣPAHs) was from 157. 9 to 858. 0 ng / L. The horizontal distribution illustrated that the concentration of ΣPAHs decreased as salinity increased. Based on ratio analysis,PAHs have complicated sources. A Level III fugacity model was developed to simulate the multimedia fate of PAHs and to study the air-water exchange fluxes of three PAHs( phenanthrene,pyrene,benzo[a]pyrene) in the Jiulong River Estuary. The calculated concentration of PAHs was similar to that measured in this study or reported in earlier literature. At 16℃,the net atmosphere deposition fluxes of these PAHs were 17. 38,7. 86 and 8. 38 μg / day / m2. Phenanthrene was predominant in the atmospheric deposition. The net atmospheric deposition fluxes of these PAHs all decreased with tem-perature. When the temperature was above 32. 0℃,benzo[a]pyrene was released from the water into the air.国家自然科学基金(40776044);; 福建省自然科学基金(2012J05078);; 福建省杰出青年科学基金(2014J06014);; 中央高校基本科研专项(20720140507
Tannin dynamics of Kandelia candel roots in different salinity culture
对不同盐度(0‰-40‰)栽培下秋茄根的总酚、可溶性缩合单宁、结合缩合单宁、总缩合单宁的含量进行测定,探讨盐度对单宁生产的效应.结果表明:(1)不同盐度下栽培60-135d,总酚含量在相同盐度条件下随栽培时间的延长呈现出先波动而后升高的趋势,其中总酚最高含量出现在高盐度,说明一定的高盐度胁迫可以促进总酚的合成;总缩合单宁与可溶性缩合单宁含量变化趋势相似,其中可溶性缩合单宁含量显著高于结合缩合单宁.(2)在15‰盐度下栽培75-135d,秋茄根不同部位的总酚、可溶性缩合单宁、结合缩合单宁和总缩合单宁含量有相似的变化趋势,即由根尖往远离根尖的部位呈下降趋势.Total phenolics(TP),extractable condensed tannins(ECT),bound condensed tannins(BCT),and total condensed tannins(TCT) contents of Kandelia candel roots in different salinity culture were determined.In addition,the effect of salinity on tannin production was studied.The results showed as follows:(1) During the period of different salinity culture(from 60 d to 135 d),TP content fluctuated with increasing salinity,with the highest occurring in high salinity.ECT and TCT contents fluctuated under different salinity conditions with a consistent pattern.ECT contents were significantly higher than BCT contents.(2) At culture salinity of 15‰,the distribution of tannins in different parts of roots in the same period from 75 d to 135 d followed the identical pattern: the closer the root tip was,the higher the TP,ECT,BCT,and TCT contents were.福建省自然科学基金资助项目(B0410006);; 国家自然科学基金资助项目(40376026
与南海西边界流有关的区域海洋学进展
从动力学角度,回顾了与南海西部主流系及其涡旋研究有关的南海物理海洋学的进展.主要内容涉及南海西边界流漂流浮标观测、西边界流源区涡旋遥感观测、西边界流源区跨陆架交换、涡流相互作用、西边界流年际变化、西边界流区海气相互作用、南海贯穿流等方面的进展.西边界流是一个强流系,其与季节和年际变化相关的结构特征、变率及跟某些动力过程的关联有待研究.在西边界流变率、涡旋环流相互作用、海气过程以及南海贯穿流取得了以下成果:(1)利用漂流浮标观测样本对南海西边界环流进行分析,指出南海西边界表层环流在到达越南中部沿岸后伴随着流幅变窄的同时流速加强;探讨了南海北部环流变化机理,定量诊断南海西边界流北支冬季逆风流产生的动力机制;利用航次数据对18°n断面的经向地转流进行诊断,表明南海西边界流的经向输送年际变化明显;(2)结合航次观测数据,对2003/2004年冬季南海北部2个反气旋涡旋和2007年夏季18°n附近的3个反气旋涡旋进行研究,指出冬季2个涡旋产生后以罗斯贝(rOSSby)波速度(约0.1M/S)沿北部陆坡向西南方向传播,并初步揭示了南海西边界环流与夏季3个涡旋的相互作用;南海北部陆架区涡旋西南向传播最大(最大为0.09M/S),而越南以东海域涡动能(EkE)最大,这都说明涡旋活动与南海西边界流存在强的相互作用;(3)发现南海西边界流附近海表面温度(SST)强的季节内振荡特征,进一步研究表明此区域冬季SST季节内变化会使潜热季节内信号减弱20%;(4)探讨了南海贯穿流的长期变化特征以及与整个太平洋环流系统的相互关联.国家自然科学基金重点项目(40830851); 国家重点基础研究发展计划(2011CB403504); 中国科学院近海海洋观测研究网络——西沙南沙海洋观测研究站建设项目(KZCX2-EW-Y040)资
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