非典与中国的电子商务

探讨了非典对于中国电子商务的影响以及电子商务在此期间发挥出的作用、存在的不足，进而提出了关于如何促进中国电子商务进一步发展的思考和建议．     

如何行成关系数据模型到面向对象数据模型的映射

关系数据模型是基于记录的基本数据模型;面向对象数据模型是基于对象的基本数据模型;两种数据模型在某种程度上应存在相互映射和相互转变的可能性,它们的相互映射和相互转变将使关系数据库和面向对象数据库之间的转变成为可能。     

论搜寻品假冒伪劣的成因及其市场影响

搜寻品假冒伪劣是指消费者主动选择购买假冒伪劣产品。其形成原因是这类假冒伪劣产品相对于“正品”的巨大价格优势。它虽然对假冒伪劣产品的生产者、销售者和消费者有利 ,但不利于新产品的研发和生产 ,会妨碍产品质量的提高乃至造成市场上产品整体质量的降低 ,从而也损害消费者的长远利益。     

对第二语言习得中“年龄小优势论”的辩证分析

多数人认为:在第二语言习得过程中,年龄小的人比年龄大的人学得好;儿童比成年人学得好。通过对大量的有关年龄因素如何影响"第二语言习得"(SLA)的资料的辩证分析,肯定了在自然条件下,就语音和语法方面而言,年龄越小,学得越好,但年龄大的人在读写方面的优势以及成年人比儿童能够更快地习得第二语言语法的事实证明了:在"第二语言习得"中,年龄小的人并非总是比年龄大的人学得好,从而论证了"年龄小优势论"具有一定的片面性。     

Bias Correction in the Dynamic Panel Data Model with a Nonscalar Disturbance Covariance Matrix

Approximation formulae are developed for the bias of ordinary and generalized Least Squares Dummy Variable (LSDV) estimators in dynamic panel data models. Results from Kiviet [Kiviet, J. F. (1995), on bias, inconsistency, and efficiency of various estimators in dynamic panel data models, J. Econometrics68:53-78; Kiviet, J. F. (1999), Expectations of expansions for estimators in a dynamic panel data model: some results for weakly exogenous regressors, In: Hsiao, C., Lahiri, K., Lee, L-F., Pesaran, M. H., eds., Analysis of Panels and Limited Dependent Variables, Cambridge: Cambridge University Press, pp. 199-225] are extended to higher-order dynamic panel data models with general covariance structure. The focus is on estimation of both short- and long-run coefficients. The results show that proper modelling of the disturbance covariance structure is indispensable. The bias approximations are used to construct bias corrected estimators which are then applied to quarterly data from 14 European Union countries. Money demand functions for M1, M2 and M3 are estimated for the EU area as a whole for the period 1991: I-1995: IV. Significant spillovers between countries are found reflecting the dependence of domestic money demand on foreign developments. The empirical results show that in general plausible long-run effects are obtained by the bias corrected estimators. Moreover, finite sample bias, although of moderate magnitude, is present underlining the importance of more refined estimation techniques. Also the efficiency gains by exploiting the heteroscedasticity and cross-correlation patterns between countries are sometimes considerable.     

名词性复合词的意义建构诸理论述评

名词性复合词的意义建构是一个看似简单,实际上非常复杂的过程。传统语法把这一意义建构过程简单化,认为名词性复合词的意义等于各组成部分名词的意义总和。转换生成语言学家 意义特征理论学家也都提出了各自的理论解释,但都有很大的缺陷。概念合成语言学理论对名词性复合词的意义建构做出了比较完整的理论解释,但也有待于进一步的改进。     

白居易"中隐"及其对后世的影响

白居易"中隐"是以庄子的逍遥人生为理念,远离政治斗争的遂性自由的生存哲学和方式,其核心是"适",在适性逍遥的前提下,再安排对社会、家庭、国家、民族的责任.这是一种强调个体生命高于一切的现代人本主义精神,在儒家思想占据统治地位的专制集权社会,这一思想是超前的.而且,其适性逍遥并不是其最终的目标,其最终的目标是以适性逍遥为保证,实现自己的自由自在的艺术创造.故白居易"中隐"对后世苏轼、明代三袁均有很大影响,但毕竟时代不同了,这种影响终于以浪漫精神衰退为特点走向另一种形态.     

Goodness of fit for the inverse Gaussian distribution

For testing the fit of the inverse Gaussian distribution with unknown parameters, the empirical distribution-function statistic A² is studied. Two procedures are followed in constructing the test statistic; they yield the same asymptotic distribution. In the first procedure the parameters in the distribution function are directly estimated, and in the second the distribution function is estimated by its Rao-Blackwell distribution estimator. A table is given for the asymptotic critical points of A². These are shown to depend only on the ratio of the unknown parameters. An analysis is provided of the effect of estimating the ratio to enter the table for A². This analysis enables the proposal of the complete operating procedure, which is sustained by a Monte Carlo study.     

低浓度三分子反应模型双曲型反应－扩散方程的稳定性与化学振荡

考虑浓度扩散和扩散流随时间的变化，得到低浓度三分子反应模型的双曲型反应－扩散方程；讨论了方程的稳定性及存在行波解的条件，得到了化学振荡的色散关系和相速度．     

普通野生稻和药用野生稻种子休眠性的研究

对普通野生稻和药用野生稻种子休眠的原因进行了探讨,表明野生稻种的遗传特性、形态性状、颖壳的透性和种子的生理特性与种子休眠有关。研究结果为打破野生稻种子休眠、提高其发茅力提供了依据和适宜的方法。