公司并购与全要素生产率变化研究

对并购绩效的研究表明并购通常不能创造股东超额收益,但从并购前后企业全要素生产率的变化来看,大部分企业的产出效率得到了显著提升。本文通过对我国上市公司2002—2014年并购案例的研究发现,并购重组能够提升企业的全要素生产率,企业全要素生产率的增长是通过技术效率、生产效率和配置效率三个方面实现,而规模效率对企业产出效率增长的贡献不明显。国家社会科学基金青年项目“我国国有上市公司政治控制成本研究”(71302072

Noise reduction of excavator cooling fan and wind scooper based on CFD

针对某型挖掘机在工作过程中冷却风扇出口端噪声水平严重超标的问题,对风扇在旋转过程中的气动性能进行了研究。首先,建立了风扇与导风罩所形成的流体域有限元模型。基于Cfd理论,运用fluEnT软件对其流场进行了稳态数值模拟。分别探究了风扇与导风罩相关结构参数对其风量大小与噪声水平的影响。结合厂商提供的散热系统选型软件OPTIMISEr,兼顾风量与噪声要求,得到了最适合该挖掘机的风扇及导风罩型号。优化结果表明,在提供相同风量的前提下,优化后的风扇噪声比原风扇的噪声降低了1.5 d b左右。随后,对该流体域进行了瞬态仿真,分析了风扇噪声的频率特性。仿真结果表明,风扇旋转噪声主要集中在低频段,为企业有针对性地对该频段噪声采取降噪措施提供了指导。Aiming at the problem that the noise level on the outlet side of the cooling fan exceeded the national standard seriously during the working process of an excavator,researches on the aerodynamic performances of revolving fan were carried out.Firstly,the finite element model of the fluid domain which was formed by the fan and the wind scooper was established.Steady-state numerical simulations for the flow field were conducted by using Fluent based on CFD theory.The effects of relevant structural parameters of fan and wind scooper on their blowing rate and noise level were explored respectively.Taking account of both wind and noise requirements,the most suitable type of fan and wind scooper for the excavator were obtained by using Optimiser,a cooling system selection software provided by the manufacturer.The optimization results indicate that the noise of optimized fan reduced 1.5 d B compared to that of original one under the premise that it can provide the same wind as before.Then,transient simulations for the flow field were done to analyze the frequency performances of fan noise.The simulation results indicate that the rotation fan noise concentrates mainly on low frequency stage which guided the company to take noise reduction measures for this frequency band noise specifically.国家科技支撑计划资助项目(2013BAF07B04); 福建省自然科学基金计划资助项目(2014J01210

聚酰胺硅胶吸附茶多酚的红外光谱研究

IR谱表明:聚酰胺硅胶吸附剂中,聚酰胺的N—H和硅胶表面OH以氢键结合,υC=O无位移;室温下该吸附剂中C=O和茶多酚中O—H作用后,υC=O和υO—H分别红移了11cm-1和18cm-1;而与咖啡因及氨基酸作用后υC=O无位移

The Research on Merger & Acquisition Efficiency for Listed Companies in China

本文在对并购效率研究方法和文献梳理的基础上，从生产要素效率的角度去评价我国上市公司的并购效率及探索企业并购价值创造的来源，并从并购利益相关者角度分析对并购效率进行了研究，以弥补用单一或几个利益主体标准评价时的不足。本文首先对我国上市公司的并购历史进行了回顾，发现随着上市公司的并购模式不断成熟，以实现产业整合、转移和产业升级为目的的并购活动不断增加，在全球金融危机后全球并购市场低迷的情况下，我国企业的并购活动如火如荼。本文正是在此背景下来研究我国上市公司的并购效率，考察我国企业并购活动能否优化资源配置。 研究的内容主要包括：首先，我国上市公司的并购历史进行了阶段划分，发现我国企业的并购活动有明...Based on the review of merger and acquisition efficiency evaluation methods and literature, this dissertation evaluates the M&As’ efficiency of Chinese listed companies from the aspect of total factor production(TFP) efficiency .The sources of additional value created in M&A are also expored.To compensate for the deficiency of single or several stakhoders’ benefits criteria, this paper also st...学位：管理学博士院系专业：财务管理与会计研究院_财务学学号：2782011015350

The Implementation Results of SOP in China's Listed Companies

股权激励制度设计的初衷是为了减弱代理问题,因此考察股权激励的实施效果应该首先直接考察它能否缓解经理人的代理问题,然后才是对公司绩效的影响。利用2006—2014年我国沪深两市A股上市公司面板数据,从代理成本和公司绩效两个层面研究我国股权激励实施效果,结果表明:上市公司实施股权激励可抑制投资不足行为,却加剧了经理人的过度投资行为;股权激励计划并不能显著降低经理人的在职消费,由此而带来的以ROA衡量的公司绩效改善也并不显著,这从两个层面说明我国股权激励计划的激励效果并不明显。Stock Option Plan （SOP） was originally designed to weaken the agency problem, therefore we should examine whether it can alleviate the agency problem of managers directly to investigate the effect of the implementation of SOP, and then the impact on corporate performance.This paper studies the implementation results of stock option plan（SOP） in China from the aspects of agency costs and firm performance, using a 2006--2011 panel data of listed companies in Shanghai and Shenzhen A-share market. We find stock option plan can alleviate underinvestment behaviors significantly, while it exacerbates the overinvestment behaviors of managers. Stock option plan cannot decrease the non-pecuniary compensation, and hence the reduction of agency costs does not bring significant improvement of firm performance measured by ROA.西藏科技厅重点科技计划软科学项目；西藏自治区哲学社会科学专项资金项目(16BJY005)

Duration,Trading Information and Investor Behavior——A Study Based on PCD Model

使用PCd模型,通过引入买卖价差、交易量、交易规模、委托指令流等交易信息变量探讨交易信息对投资者行为的影响。实证研究表明,买卖价差与期望交易持续期显著正相关,不支持EASlEy和O’HArA(1992)的观点。同时大规模的交易能够显著地延长交易持续期,而中等规模的交易能够减小交易持续期,证实了知情交易者的隐藏交易假说。指令流信息中的买卖申报数量也对交易持续期有显著的影响,上期买卖申报数量与本期交易持续期正相关。This paper studies the impact of trading information such as bid-ask spread,trading volume,transaction size,and order flow information on investor behavior.Empirical result of the PCD model shows that the bid-ask spread was significantly correlated with the expected duration,which is not consistent with Easley and O'Hara(1992).While large-scale trading is significantly correlated with longer duration,but medium-size transactions is often with shorter durations.It confirms the Stealth Trading Hypothesis of the informed traders.Order flow information such as the amount of trading quotes is positively correlated with duration.西藏自治区哲学社会科学专项资金项目(15BJY002); 四川省社会科学基金项目(SC14XK23); 四川县域经济研究中心项目(xyzx1503

Are Analysts Inclined to Follow Up Corporations with Good Social Responsibility Performance?

本文以2008年-2010年沪深上市公司为样本,运用短面板数据以及个体和时间双向固定效应模型,实证检验了分析师跟进与企业社会责任表现之间的关系。研究发现(1)企业社会责任表现对分析师跟进程度具有正向影响,且这种影响具有滞后性;(2)高公司治理水平能够增强社会责任表现对分析师跟进程度的正向影响。研究结果为推动企业积极履行社会责任、优化公司治理结构和引入社会责任报告第三方鉴证指引了方向。Using a sample of listed companies in SSE and SZSE for the period 2008-2010, this paper introduces short panel data and two-way fixed effects model to test the relationship between analyst follow-up and the performance of corporate social responsibility(CSR).We find that CSR performance has a positive impact on analyst follow-up, however such impact is a little lagged.We also find that high level of corporate gov-ernance can enhance the positive relationship between analyst follow-up and CSR performance.The results indicate that corporations should fulfill their social responsibilities, optimize the corporate governance structure and introduce the independent third parties to attest the social responsibili-ty reports.国家自然科学基金项目“全球金融风暴背景下中国企业财务决策行为研究”(批准号70972110)的资

行星齿轮式两挡变速器匹配与结构设计验证

为解决直驱式电动汽车平均传动效率较低及传统双轴式两挡变速器结构不够紧凑等问题，提出了一种用于电动乘用车的行星齿轮式两挡变速器方案。完成了动力传动系统参数匹配，通过AVL Cruise初步验证了参数匹配的合理性；根据匹配结果，对行星齿轮式两挡变速器进行了结构参数设计，并据此对传动比等关键参数进行了修正；基于CATIA建立了变速器的三维模型，对其关键部件进行了强度验证；通过与常用直驱方案的对比表明，整车百公里加速时间缩短了0.31 s，最大爬坡度由直驱方案的34%增加到37%，最高车速提高了21 km/h，NEDC工况下的续航里程增加了18 km，提出的行星齿轮式两挡变速器可有效提高整车的动力性和经济性