蒙古语近音近义词刍议

以往对蒙古语近义词的研究 ,只从词义之间的关系出发 ,重点放在解释近义词的意义差别上 ,却很少涉及它的形式结构。虽然蒙古语绝大多数近义词的语音形式相互间毫无关系 ,但是 ,有些近义词的构成 ,具有一定的语音学和形态学基础。通过语音手段构成的近义词是由同一词分化而产生 ;通过形态手段构成的近义词是由同根词派生出来的     

实数域及四元数除环上有平方根的方阵

给出了实数域及实四元数除环上方阵有平方根的充分必要条件．     

The Robustness of Trend Stationarity: An Illustration with the Extended Nelson-Plosser Dataset

We re-evaluate Andreu and Spanos's findings in favour of trend stationarity by considering the extended Nelson-Plosser data set. This expanded (to 1988) data set includes a period of rather different behaviour compared with the original Nelson-Plosser data used by Andreou and Spanos. We find that Andreou and Spanos's models (with only minor adjustments) exhibit remarable stability over this extended period, and indicate that their conclusions are more robust than they have shown.     

物流成本对国际贸易影响的实证分析

多年来中美贸易发展迅速 ,美国成为我国主要出口国家。当今形势下 ,物流成本成为影响中美贸易的主要因素 ;借助计量经济学方法 ,定量地探讨了物流成本对两国贸易尤其是我国出口贸易的影响。     

强苯赛对水稻幼苗根系生长的影响

强苯赛浸种对水稻幼苗的根长、根重和根系体积都有促进作用,能提高根尖细胞分裂指数,能使胚根尖切段伸长和发根力增强,并能提高胚乳中淀粉酶活性和根系的呼吸强度。     

Seemingly unrelated regression on the autoregressive (Ar(p)) singular equation system

This paper studies the estimation of seemingly unrelated regressions (SUR) of singular equation systems with an autoregressive error process (AR(p)) for each equation.Parameter estimates of the autoregressive singular equation system are not generally invariant to the equation deleted. Under the model specification restriction on the autoregressive parameters, the invariance property is preserved, and this paper shows that a single equation generalized least squares (GLS) estimation for a general autoregressive error process is equivalent to the SURGLS estimation of the AR(p) singular equation system.     

拐点和一元三次方程的求根公式

用一元函数微分学理论，对一元三次实系数方程x^3 bx^2 cx d=0的求根问题作了新的探讨。     

论海外潮人的恋根情结——以侨领林义顺、蚁光炎为例

辛亥革命时期新加坡的林义顺和抗日战争时期泰国的蚁光炎是近代两位具有典型意义的海外潮人侨领 ,从他们对故乡和祖国不遗余力的支持与帮助的具体事迹 ,可以看见海外潮人极为突出的文化特征———浓重的恋根情结 ,文章探讨了由这种恋根情结升华起来的强烈的报国意识及其所赖以生成的深层文化基因 ,以及这种恋根情结在现代社会尤其在未来的知识经济时代所可能产生的正负面影响。     

加强思想道德教育着力从源头上防治腐败

改革开放以来,我国社会生活中出现了腐败现象蔓延的趋势,尤其是党政干部中存在比较严重的贪污受贿、以权谋私。腐败现象的存在有复杂的原因,理想信念的破灭、思想道德素质的滑坡是滋生腐败的根本原因之一。预防和治理腐败要靠法律和制度,也要靠思想道德教育,这是预防和治理腐败的根本措施。     

Improved model selection criteria for SETAR time series models

The purpose of this paper is threefold. First, we obtain the asymptotic properties of the modified model selection criteria proposed by Hurvich et al. (1990. Improved estimators of Kullback-Leibler information for autoregressive model selection in small samples. Biometrika 77, 709–719) for autoregressive models. Second, we provide some highlights on the better performance of this modified criteria. Third, we extend the modification introduced by these authors to model selection criteria commonly used in the class of self-exciting threshold autoregressive (SETAR) time series models. We show the improvements of the modified criteria in their finite sample performance. In particular, for small and medium sample size the frequency of selecting the true model improves for the consistent criteria and the root mean square error (RMSE) of prediction improves for the efficient criteria. These results are illustrated via simulation with SETAR models in which we assume that the threshold and the parameters are unknown.