批发零售行业盈余管理实证研究

随着今年来我国股票市场的高速发展，上市公司为了达到配股条件而进行盈余管理的现象也层出不穷，本文通过对批发零售行业上市公司财务数据的分析，计算出各公司的净资产收益率（ROE）和总资产收益率（ROA），发现这些上市公司为了避免亏损或为了获得配股权而通过盈余管理将ROE维持在略高于0．6％与10％的区间上的证据；进一步分析了ROA的分布，发现其与ROE的分布存在系统性差异，说明上市公司为了达到配股及格线可能操纵了净资产。另外，使用收益激进度衡量了该行业上市公司的收益透明度，发现各公司收益激进度和当年配股政策有一定的关系。     

中国上市公司宣布配股信息前后的盈余管理

上市公司为了取得股权再融资的资格,在配股以前存在强烈向上的盈余管理动机.通过对242例中国A股上市公司宣布配股信息前后的盈余管理的实证研究,发现中国配股企业在宣布配股信息前两年和宣布配股信息当年存在远高于成熟证券市场和其他新兴证券市场的盈余管理行为,而在宣布配股后第2年和第3年,配股企业没有进行盈余管理,同时还发现信用交易是配股企业盈余管理的重要工具.     

上市公司利用资产减值准备进行盈余管理的原因探析

近年来,有关实证会计研究结果表明,我国上市公司存在着大量的盈余管理行为,这严重影响了会计信息的真实可靠性,误导了信息使用者的经济决策。在盈余管理使用的多种手法中,资产减值会计又是目前上市公司通过巨额冲销和收益最大化实施盈余管理的最大法宝。资产减值会计之所以成为上市公司进行盈余管理的最主要手段,主要是由会计准则与会计制度的不完备性、会计本身的模糊性和灵活性、会计信息的不对称性、盈余管理的收益大于成本等原因所造成。     

上市公司高管变更前后的盈余管理初探

随着我国证券市场的逐步发展,盈余管理成为财务会计研究的新课题。在我国,由于市场环境条件的影响,由高管变更引发的盈余管理成为上市公司的主要问题。高管变更过程中有可能会发生重大的亏损,上市公司为了获得配股资格,极有可能操纵会计盈余,以达到规定的净资产收益率。通过对定义分析,可见其存在几种盈余管理的观点,据此建议区分盈余管理与利润操纵、利润控制及损益调整的关系。     

上市公司盈余管理防范对策研究

我国的上市公司为了上市及配股,进行盈余管理的现象十分严重,盈余管理是上市公司出于自身目的从事会计造假的手段,对经济造成了巨大危害.因此在揭示了盈余管理的种种动机之后,从上市公司的内部、外部寻找了若干防范盈余管理的对策.     

企业生命周期视角下的归类变更盈余管理

以2011~2015年我国沪深A股制造业上市公司作为研究样本，运用多元线性回归方法，分析了不同生命周期阶段的企业归类变更盈余管理行为.研究表明：处于不同生命周期阶段的企业均存在归类变更盈余管理行为，且归类变更盈余管理行为呈现出策略性选择的特点.上述结论对进一步完善我国会计准则、改善监管质量，具有一定的监管启示意义.     

新旧准则下资产减值盈余管理及其经济后果的对比分析

以新旧资产减值政策为背景,对比研究在不同政策背景下企业计提资产减值的动机,特别是新准则的实施是否如预期有效遏制上市公司利用资产减值进行盈余操纵.检验表明,新准则下企业依然可以利用资产减值实现扭亏、配股等目标,这表明,在禁止部分资产减值转回的情况下,企业可能存在别的隐蔽渠道.盈余管理与市场反应的回归结果表明市场并没有对企业的盈余管理行为区别对待,或者说,市场并没有看穿企业利用资产减值实行盈余管理的行为.     

企业生命周期视角下的归类变更盈余管理——来自中国制造业上市公司的经验证据

以2011～2015年我国沪深A股制造业上市公司作为研究样本,运用多元线性回归方法,分析了不同生命周期阶段的企业归类变更盈余管理行为.研究表明:处于不同生命周期阶段的企业均存在归类变更盈余管理行为,且归类变更盈余管理行为呈现出策略性选择的特点.上述结论对进一步完善我国会计准则、改善监管质量,具有一定的监管启示意义.     

中外上市公司盈余管理动机的比较研究

随着资本市场的发展,公司管理层通过盈余管理粉饰公司业绩,误导投资者决策的行为受到广泛的关注。对比中外学者对盈余管理的研究发现,国外上市公司盈余管理的典型动机有三类：资本市场动机,契约动机与规避监管动机。在中国上市公司中,前两类动机并未得到显著的体现,规避监管动机是中国上市公司盈余管理的典型动机。中国上市公司盈余管理的受益者是控股股东,控股股东对上市公司的利益剥夺是盈余管理的深层驱动力。     

退市制度变更对上市公司盈余管理行为的影响

以2012年沪深交易所对退市制度的修订为切入点,选取2008~2015年沪深两市A股主板上市公司作为研究样本,运用盈余分布法和多元回归实证检验了退市制度变更对上市公司盈余管理行为的影响.结果表明:退市制度变更后,避免净利润为负的盈余管理行为略有减少,而避免净资产为负的盈余管理行为显著增加.且退市制度变更诱发了避免营业收入低于1000万元的盈余管理行为,上市公司实施的应计盈余管理显著减少,而其实施的销售操纵、费用操纵和生产操纵等真实盈余管理显著增加.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

<正>~~     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。