论1928-1930年陕西大旱灾的救荒

民国时期陕西省自然灾害接连不断，其中最为惨烈的是1928--1930年的大旱灾。旱灾发生以后，国民政府和民间社会给予了相当的重视，积极救灾，取得了一定的成效。由于种种约制因素的存在，使救灾效果受到了严重削弱。但是救灾也有其积极方面，国民政府通过救荒，权力得到了深化，政府控制能力得到加强。     

敦煌本《大方等大集经》残卷缀合研究

《大方等大集经》是大乘佛教大集部经典的汇编,由北凉昙无谶、北齐那连提耶舍、隋那连耶舍等数代经师接续翻译而成。在现已刊布的敦煌文献中,该经共有171号,除4号某一卷首尾完整外,其余167号均为残卷或残片,其中不乏原属同一写卷而被撕裂为数号者。依据内容前后相承、残卷断痕或残字相互契合、乌丝栏等行款相同、书写风格或笔迹相近以及背面内容相合等因素,可将其中的38号残卷或残片缀合为13组。敦煌残卷的缀合是进一步整理研究的基础。通过缀合,除使原本身首异处的残卷或残片重聚之外,还纠正了《国家图书馆藏敦煌遗书》或《英国国家图书馆藏敦煌遗书》条记目录对北敦9793号、北敦11119号、斯627号等残卷著录信息的错误,更为进一步定名、断代及校理创造了条件。     

A Pitman measure of similarity in k-means for clustering heavy-tailed data

One of the most popular methods and algorithms to partition data to k clusters is k-means clustering algorithm. Since this method relies on some basic conditions such as, the existence of mean and finite variance, it is unsuitable for data that their variances are infinite such as data with heavy tailed distribution. Pitman Measure of Closeness (PMC) is a criterion to show how much an estimator is close to its parameter with respect to another estimator. In this article using PMC, based on k-means clustering, a new distance and clustering algorithm is developed for heavy tailed data.     

问候语“无它乎？”的文化解读

问候语是人类使用频率很高、使用人数很广的一种言语。不同的民族在不同时期有不同的问候语,能反映出他们不同的心理性格和时代特征。“无它乎？”是我国最早的日常问候语,从中可以看出先民们艰苦险恶的生存环境,是他们真实生活的写照;折射出中国文化以人为本的哲学思想,表现了对他人的关爱精神;透视出先民们因畏而敬的原始宗教信仰以及民风习俗;体现出博大精深的语言魅力,反映了人类历史的变化和社会文明的进步,具有丰富的文化内涵。探讨问候语对我们处理人际关系和构建平安和谐社会都具有重要的现实意义。     

New Reduced-bias Estimators of a Positive Extreme Value Index

Noting that the classical Hill estimator of a positive extreme value index (EVI) is the logarithm of the mean of order-0 of a set of certain statistics, a more general class of EVI-estimators based on the mean of order-p (MOP), p ? 0, of such statistics was recently introduced. The asymptotic behavior of the class of MOP EVI-estimators is reviewed, and compared to their reduced-bias MOP (RBMOP) and optimal RBMOP versions, which are suggested here and studied both asymptotically and for finite samples, through a large-scale simulation study. Applications to simulated datasets are also put forward.     

Model-based clustering with non-elliptically contoured distributions

The majority of the existing literature on model-based clustering deals with symmetric components. In some cases, especially when dealing with skewed subpopulations, the estimate of the number of groups can be misleading; if symmetric components are assumed we need more than one component to describe an asymmetric group. Existing mixture models, based on multivariate normal distributions and multivariate t distributions, try to fit symmetric distributions, i.e. they fit symmetric clusters. In the present paper, we propose the use of finite mixtures of the normal inverse Gaussian distribution (and its multivariate extensions). Such finite mixture models start from a density that allows for skewness and fat tails, generalize the existing models, are tractable and have desirable properties. We examine both the univariate case, to gain insight, and the multivariate case, which is more useful in real applications. EM type algorithms are described for fitting the models. Real data examples are used to demonstrate the potential of the new model in comparison with existing ones.     

Semi-parametric tail inference through probability-weighted moments

In this paper, for heavy-tailed models, and working with the sample of the k largest observations, we present probability weighted moments (PWM) estimators for the first order tail parameters. Under regular variation conditions on the right-tail of the underlying distribution function F we prove the consistency and asymptotic normality of these estimators. Their performance, for finite sample sizes, is illustrated through a small-scale Monte Carlo simulation.     

重金属污染土壤的治理

在前人研究的基础上，总结了重金属污染土壤的治理技术。根据治理后重金属的去向将其分为两大类：将重金属从土壤中去除的技术；土壤滞留-脱离食物链的技术。按照治理方法的原理作了进一步划分，分类评述了各种方法的运用前景和条件。     

Parameter estimation for fractional Poisson processes

The paper proposes a formal estimation procedure for parameters of the fractional Poisson process (fPp). Such procedures are needed to make the fPp model usable in applied situations. The basic idea of fPp, motivated by experimental data with long memory is to make the standard Poisson model more flexible by permitting non-exponential, heavy-tailed distributions of interarrival times and different scaling properties. We establish the asymptotic normality of our estimators for the two parameters appearing in our fPp model. This fact permits construction of the corresponding confidence intervals. The properties of the estimators are then tested using simulated data.     

重金属脱除剂——SCX的研制

本文报导了甘蔗渣纤维素黄原酸酯(SCX)的制备方法及用于脱除水溶液中重金属离子的初步结果.