中亚东干族文化传统及近年中亚地区汉语教学的发展

中亚东干族是中国陕甘回民的后裔,是因战争迁徙而聚居于哈、吉、乌三国的华人群体。本文考察中亚东干族的形成,分析其突出的文化表征,阐述东干文化对中国汉文化的继承,介绍国内对东干留学生的汉语教学与中亚地区汉语教学的现状及发展前景。     

A variable-neighbourhood search algorithm for finding optimal run orders in the presence of serial correlation

The responses obtained from response surface designs that are run sequentially often exhibit serial correlation or time trends. The order in which the runs of the design are performed then has an impact on the precision of the parameter estimators. This article proposes the use of a variable-neighbourhood search algorithm to compute run orders that guarantee a precise estimation of the effects of the experimental factors. The importance of using good run orders is demonstrated by seeking D-optimal run orders for a central composite design in the presence of an AR(1) autocorrelation pattern.     

On distribution-weighted partial least squares with diverging number of highly correlated predictors

Summary.  Because highly correlated data arise from many scientific fields, we investigate parameter estimation in a semiparametric regression model with diverging number of predictors that are highly correlated. For this, we first develop a distribution-weighted least squares estimator that can recover directions in the central subspace, then use the distribution-weighted least squares estimator as a seed vector and project it onto a Krylov space by partial least squares to avoid computing the inverse of the covariance of predictors. Thus, distrbution-weighted partial least squares can handle the cases with high dimensional and highly correlated predictors. Furthermore, we also suggest an iterative algorithm for obtaining a better initial value before implementing partial least squares. For theoretical investigation, we obtain strong consistency and asymptotic normality when the dimension p of predictors is of convergence rate O { n ^1/2/ log ( n )} and o ( n ^1/3) respectively where n is the sample size. When there are no other constraints on the covariance of predictors, the rates n ^1/2 and n ^1/3 are optimal. We also propose a Bayesian information criterion type of criterion to estimate the dimension of the Krylov space in the partial least squares procedure. Illustrative examples with a real data set and comprehensive simulations demonstrate that the method is robust to non-ellipticity and works well even in 'small n –large p ' problems.     

12世纪前中央亚细亚草原的鞑靼人及其国家

波斯史学家拉施特丁的《史集》为研究蒙古人统治之前中央亚细亚草原上鞑靼人的历史提供了重要信息。拉施特丁认为,蒙古人统治之前中央亚细亚草原地区的居民以突厥部落为主,其组织"结构"为6个鞑靼人国家。本文以鄂尔浑和叶尼塞河流域突厥如尼文碑铭记载为依据,参照汉文史籍、敦煌和波斯手稿等的记载,探讨了9—12世纪在甘肃和新疆的广阔地域内活动的鞑靼人及其政权、9世纪上额尔齐斯河流域基马克人及其部落联盟的形成与鞑靼人之间的关系。     

Estimation of variance in bivariate normal distribution after the preliminary test of homogeneity

A preliminary test estimator of variance in the bivariate normal distribution is proposed after the Pitman–Morgan test of homogeneity of two variances. The bias and mean square error of the estimator are derived. The relative efficiency (RE) of the preliminary test estimator is studied. Computations and 3D graphs of RE for different parameters are analyzed. In order to get the maximum RE, recommendations of the significance level for the preliminary test are given for various sample sizes by using the max–min criterion.     

中部六省省会城市土地集约利用评价及时空比较研究

利用文献资料法、AHP法、综合评价法、理论分析与实证分析相结合对中部六省省会城市2001年和2007年土地集约度进行评价,通过时空比较分析提出相关建议。研究结果表明：中央提出中部崛起战略后,中部六省省会城市土地集约利用水平有明显提高,但地区水平差异慢慢拉大。建议中部城市在土地集约利用过程中应积极发挥＂后进优势＂,尽量避免＂先进劣势＂。     

优化进出口商品结构转变外贸增长方式

近时期我国外贸工作的重点是,加快转变外贸增长方式,优化进出口商品结构,鼓励高新技术产品和机电产品出口,继续限制资源性、高耗能、高污染产品出口,提高利用外资质量,促进国内产业升级.我国贸易增长方式的转变关键在于国内产业结构的转变,而产业结构的转变是一个比较长期的过程.要优化进出口商品结构,着力提高对外贸易的质量和效益.     

中亚与我国西北边疆地区同源跨国民族问题

本文认为,当今世界跨国民族问题引发的各种矛盾与冲突,往往受主体民族与母族文化的影响;对于跨国民族的发展需要始终关注两方面的问题:其一,是否促进所在国与客位国经济发展、社会稳定和民族团结;其二,是否影响所在国和客位国经济发展、社会稳定和民族团结。中亚与我国西北边疆同源跨国民族形成的原因是历史的变迁。当前,中亚与我国西北边疆跨国民族问题中一个突出的问题就是民族主义的泛滥,成为影响主位国和客位国社会稳定乃至边疆安全的一个现实问题。     

关于环境伦理学定位的思考

当代环境伦理学家为人类保护环境确立了不同的伦理定位即生态中心主义和人类中心主义,本文认为环境保护应该坚持人类中心主义,人是最终目的,只有这样才能为环境保护提供伦理基础。