衡阳市钢管线产业集群发展现状及对策

当今世界经济的竞争主体正在逐渐地从单个企业转变为企业集团之间的竞争。作为衡阳市经济发展的支柱性产业，钢铁冶炼及钢管线加工制造产业在面临激烈外部竞争的情况下必须采用集群的方式整体作战。文章从集群概念和特征入手，分析了衡阳市钢铁冶炼及钢管线加工制造产业集群的现状及优势和问题，并对集群发展提出了一些对策。     

基于新经济地理学的产业集群理论综述

经济学中的新经济地理学,源于20世纪80年代对新国际贸易理论和竞争优势经济学的研究。20世纪90年代以克鲁格曼为代表的新经济地理学理论为产业集聚的产生提供了很好的解释。新经济地理学将传统的贸易理论所强调的趋同力量与20世纪50年代以来的发展经济学家所描述的趋异力量融入到一个共同的分析框架内。这样做的好处在于它使得人们可以将趋同力量与趋异力量与微观经济状况结合起来。我们可以更好地理解与经济一体化过程相关的基本倾向以及区域政策对产业集群的影响。     

A Kernel Variogram Estimator for Clustered Data

Abstract.  The variogram provides an important method for measuring the dependence of attribute values between spatial locations. Suppose that the nature of the sampling process leads to the presence of clustered data; it would be advisable to use a variogram estimator that aims to adjust for clustering of samples. In this setting, the use of a non-parametric weighted estimator, obtained by considering an inverse weight to a given neighbourhood density combined with the kernel method, seems to have a satisfactory behaviour in practice. This paper pursues a theoretical study of the cluster robust estimator, by proving that it is asymptotically unbiased as well as consistent and by providing criteria for selection of the bandwidth parameter and the neighbourhood radius. Numerical studies are also included to illustrate the performance of the considered estimator and the suggested approaches.     

城市土地集约利用评价——以安徽省为例

文章从区域空间的角度,建立城市土地集约利用的指标体系,采用主成分分析法和聚类分析法,对安徽省17个地市城市土地集约利用情况进行了分类和评价,以期为政府决策提供参考。     

中小企业集群创新的知识机理分析

详细介绍了中小企业集群的概念及发展状况，在定义知识价值链和分析集群创新的知识特征的基础上，研究了知识管理与集群创新的机理关系，通过知识管理构建集群学习型组织，提高集群组织的学习与创新能力，从而最终提高中小企业集群的核心竞争力，促进整体经济的发展。     

Comparing three bootstrap methods for survey data

Various bootstrap methods for variance estimation and confidence intervals in complex survey data, where sampling is done without replacement, have been proposed in the literature. The oldest, and perhaps the most intuitively appealing, is the without-replacement bootstrap (BWO) method proposed by Gross (1980). Unfortunately, the BWO method is only applicable to very simple sampling situations. We first introduce extensions of the BWO method to more complex sampling designs. The performance of the BWO and two other bootstrap methods, the rescaling bootstrap (Rao and Wu 1988) and the mirror-match bootstrap (Sitter 1992), are then compared through a simulation study. Together these three methods encompass the various bootstrap proposals.     

含异硫氰酸苯酯裂解碎片的铁硫羰合簇取代衍生物的合成与表征

本文使用Ｓｃｈｌｅｎｋ操作技术，以Ｆｅ３（ＣＯ）（１２）与ｐｈＮＣＳ在温和条件下反应，除了制得一取代物外，还制得一个新的二取代产物，通过元矛分析、ＩＲ、ＭＳ、１ＨＮＭＲ和１３ＣＮｈＩＲ表征，确定它们的化学式为Ｆｅ３（ＣＯ）３（ＣＮＰｈ）（μ３－Ｓ）２和Ｆｅ３（ＣＯ）７（ＣＮＰｈ）２（μ３－Ｓ）２。     

A modified cluster sampling method for estimating the bacterial density in Xanthan gum

Suppose particles are randomly distributed in a certain medium, powder or liquid, which is conceptually divided into N cells. Let p_i denote the probability that a particle falls in the ith cell and Y_i denote the number of particles in the ith cell. Assume that the joint probability function of the Y_i follows a multinomial distribution with cell probabilities p_i respectively. Take n (≤N) cells at random without replacement and put each of the cells separately through a mixing mechanism of dilution and swirl. These n cells constitute the first stage samples and the number of particles in these cells are not observable. Now conceptually divide each of n cells into M subcells of equal size and let X_ij denote the number of particles in the jth subcell of the ith cell selected in the first stage; i=1,2,…,N and j=1,2,…,M. Consequently assume that the conditional joint probability function of the X_ij given Y_i=y_i follows a multinomial distribution with equal cell probabilities. Now take m (≤M) subcells at random from each of the cells selected in the first stage sample. Assume that the numbers of particles in M×N subcells are observable. The properties of the estimator of the particle density per sample unit are investigated under the modified two-stage cluster sampling method. A laboratory experiment for Xanthan Gum Products is analyzed in order to examine the appropriateness of the model assumed in this paper.     

An overview of the Scottish multidisciplinary child protection review

Following the murder of a young child by her stepfather a ministerial review of child protection across Scotland was established. It was carried out by a multidisciplinary team of representatives from education, health‐nursing, health‐medical, police, social work and the Reporter to the Children's Hearing. The review comprised a number of subprojects and included a direct audit of the practice of all the key agencies. The views of the general public, parents, children and professionals were obtained via a set of consultation subprojects. The audit of practice was built around a set of individual, in‐depth case studies. The cases were drawn from the spectrum of child care and protection cases by sampling from cases known to health visitors, education departments, the police and social work departments. The audit considered compliance with guidance, but the key focus was on outcomes for children. The findings indicated that although there were many examples of good practice with children, a significant number of children were left unprotected or their needs were not met. The issues were not unique to Scotland and are discussed under four key areas. The paper sets out the extent of chronic need amongst the child population that the audit revealed, looks at the messages from consultation about issues of accessing help for children or by children directly, and describes some shortcomings of the current system. Finally the paper analyses the ways that the different agencies interact and sets out a model for how the system can provide a protective network for children who are in need of protection and support.     

6-乙炔基双二茂铁丙烷[Fc-C（CH3）2-（C5H4）Fe（C5H4）-C=CH]及其钴簇合物的电化学性质研究

利用循环伏安法对双二茂铁丙烷．6-乙炔基双二茂铁丙烷及其钴簇合物的电化学性质和氧化还原行为进行了研究．研究结果表明．在6-乙炔基双二茂铁丙烷及其钴簇合物中乙炔取代基、簇骨架C2Co2等均能使其两个铁原子中的电子具有更大的交互性．