盈余管理理论研究综述

本文主要梳理国内外学者对盈余管理的理论研究,从对其概念的差异,到存在的原因,盈余管理的目的、方式,及其盈余管理的利弊都做了全面的回顾与探讨,以期为从事盈余管理理论与实证研究的学者提供价值参考。     

A bioinformatic evaluation of potential allergenicity of 85 candidate genes in transgenic organisms

The potential of genetically modified organisms(GMOs) to increase allergenicity or predispositions to allergies has attracted much attention.An approach that will properly and holistically evaluate the allergenicity of GMOs is yet to be found.Here,85 transgenes that have been reported in both international and domestic studies during recent years are summarized case by case;49 of the transformed genes were from plant sources and 36 were from animal sources.EVALLERTM,a web server for the in silico assessment of potential protein allergenicity,was used to evaluate the potential of the transgenic proteins as allergens.The biomedical journals listed in Highwire(http://highwire.stanford.edu/) were searched and reviewed to decipher whether any of the transformed genes were linked to allergenicity or human health.The EVALLER analysis identified 5 allergenic genes,whilst our literature review found 11 genes that were either related to allergic cases or to clinical adverse events;all 16 of these genes have been used in GMOs.The analysis pathway that we have developed can help guide the selection of genes to be used in genetic modification.The pathway also provides a paradigm for allergenicity analysis of transgene candidates.     

求解奇异问题的一个新的修正Levenberg-Marquardt方法

基于信赖域技巧,给出了求解非线性方程组奇异问题的一个新的修正Levenberg-Marquardt方法.在弱于非奇异条件的局部误差界条件下,证明了该算法的全局收敛性和局部二次收敛性.数据测试结果表明该算法是有效的.     

电学史上的五次飞跃

通过分析电学史资料,作者对电学的发展情况在一定程度上进行了概括与总结,指出电学史上的五次重大发现对电学的发展起了巨大的推动作用,在电学史上出现了五次飞跃。文中还简略地介绍了各次发现的基本过程及指导发现者的基本思想。     

配电变压器的负荷率

本文从分析变压器运行负荷出发,提出了变电单耗概念以及计算变压器最佳负荷系数的方法,给出了确定最佳配电方案的实例。这对企业供电改造以及节电都具有实际意义。     

Incubation periods for paediatric AIDS patients

A recent seroprevalence study of newborns indicates that one in 62 children born in New York City has antibodies to the human immunodeficiency virus (HIV). The distribution of incubation periods for paediatric patients is needed to estimate future AIDS case loads from these seroprevalence data. Current estimates of incubation periods for paediatric patients are based on limited data. We use parametric and non-parametric methods to analyse incubation periods for 215 paediatric patients with AIDS whose only known route of infection is maternal. We conclude that incubation periods are longer than previously reported; that there is a distinct knee in the incubation period distribution at seven months which suggests two risk populations; and that there is an increase in incidence which is consistent with exponential growth.     

Towards a Darwinian Approach to Mathematics

In the past decades, recent paradigm shifts in ethology, psychology, and the social sciences have given rise to various new disciplines like cognitive ethology and evolutionary psychology. These disciplines use concepts and theories of evolutionary biology to understand and explain the design, function and origin of the brain. I shall argue that there are several good reasons why this approach could also apply to human mathematical abilities. I will review evidence from various disciplines (cognitive ethology, cognitive psychology, cognitive archaeology and neuropsychology) that suggests that the human capacity for mathematics is a category-specific domain of knowledge, hard-wired in the brain, which can be explained as the result of natural selection.     

主链液晶离聚物/PA1010/PP共混合金的力学性能及热行为

一种主链含磺酸基的热致液晶离聚物(LCI)作为增容剂被应用于PA1010与PP的共混改性·用DSC,TGA和拉伸试验对共混合金的热行为和力学性能进行了研究·结果表明,PA1010/PP共混合金中加入02%～06%LCI时增容作用增强·含LCI8%时,共混合金结晶温度和结晶度有较大提高,结晶完善程度略有降低,结晶速率降低,热稳定性不变·共混材料的拉伸强度为223MPa比纯PA1010的拉伸强度156MPa明显增强,LCI中磺酸基的存在对共混合金中PA1010组分影响较显著,增容机理是PA1010的酰胺基与LCI的磺酸基间强烈的相互作用·