一个基于Dublin Core元数据的超文本查询引擎

传统的WEB查询是基于HTML文档中的全文信息的，只要文档中包含某一待查询的词语，文档就会被选中，而不管该单词在文档中的作用和地位如何．提出了一种基于文档的Dublin Core元数据的查询方法，首先从HTML文档中提取出相应的Dublin Core元数据放入索引库中．当用户提出查询请求时，在索引库查找与用户请求相匹配的文档条目，然后将它们返回给用户．由于元数据是对文档资源的精确描述，因此这种查询方法得到的文档具有较高的相关性，避免了出现大量无关的查询结果．     

煤矿企业管理信息化

结合当前煤矿发展实际,举例说明了实现管理信息化给煤矿企业带来的发展机遇与挑战,针对煤矿企业在信息化建设中出现的各种问题,提出了快速实现煤矿企业管理信息化的措施。     

深化产业分工 组建区域分工网络 提高东北加工制造业竞争力

东北国有大规模企业数量过多,民营中小企业比重较低;企业“大而全”、“小而全”现象严重,产业分工协作不够,条块分割,行业竞争力不足。本文提出深化分工,拆分大企业生产链条,通过分层外包、出售、合资、租赁、合作等方式,形成分工协作,构建区域分工网络,并对东北加工制造业分工协作网络建设提出具体建议。     

基于熵权法的医药产业竞争力综合评价研究

运用熵权法,建立了医药产业竞争力综合评价指标体系,对中国大陆地区28个省市区的医药产业竞争力进行综合评价,将评价结果与因子分析综合评价结果进行对比,并用Kendall’s w检验对两种方法的一致性进行了统计检验,结果表明该方法是科学的,评价结果解释性较强。     

对学科馆员的再认识

从3个方面对学科馆员问题进行了深层次的分析,指出学科馆员应是泛在化的,不是几个馆员的职责,而是每个馆员的目标;不是一种独立的服务,而是图书馆整体服务向专业化、知识化的转型;学科馆员服务是每个图书馆在信息环境下提升自身竞争力的必然途径;学科馆员可以连接资源和用户,推动资源的有效利用,从而形成长效的可持续发展机制。     

提升山西省农产品加工业科技竞争力对策分析

结合农产品加工业的概念和行业分类标准及国家的产业政策环境,分析了山西农产品加工业发展的现状和问题,从搭建农产品加工业信息服务平台健全中介机构建设的服务机制,以农产品加工企业为中心建立山西省农产品加工业的科技创新体系,拓宽融资渠道,为科技园区建设提供资金保障三方面提出了科技创新提升山西省农产品加工业的主要对策。     

Effects of pressure on maghemite nanoparticles with a core/shell structure

The magnetic property and intraparticle structure of the γ phase of Fe₂O₃ (maghemite) nanoparticles with a diameter (D) of 5.1±0.5 nm were investigated through AC and DC magnetic measurements and powder X-ray diffraction (XRD) measurements at pressures (P) up to 27.7 kbar. Maghemite originally exhibits ferrimagnetic ordering below 918 K, and has an inverse-spinel structure with vacancies. Maghemite nanoparticles studied here consist of a core with structural periodicity and a disordered shell without the periodicity, and core shows superparamagnetism. The DC and AC susceptibilities reveal that the anisotropy energy barrier (ΔE/k_B) and the effective value of the core moment decrease against the initial pressure (P≤3.8 kbar), recovering at P≥3.8 kbar. The change of ΔE/k_B with P is qualitatively identical with that of the core moment, suggesting a down-and-up fluctuation of the number of Fe³⁺ ions constituting the core at the pressure threshold of about 4 kbar. This phenomenon was confirmed by the analysis of the XRD measurement using Scherrer’s formula. The core volume decreased for P≤2.5 kbar, whereas at higher pressure the core was restructured. For 2.5≤P≤10.7 kbar, the volume shrinkage of particle hardly occurs. There, ΔE/k_B is approximately proportional to the volume associated to the ordered fraction of the nanoparticles as seen from XRD, V_core. From this dependence it is possible to separate the core/shell contribution to ΔE/k_B and estimate core and surface anisotropy constants. As for the structural experiments, similar experimental data have been obtained for D=12.8±3.2 nm as well.     

Problems on matchings and independent sets of a graph

Let $G$ be a finite simple graph. For $X?V\left(G\right)$, the difference of $X$, $d\left(X\right)?\left|X\right|?\left|N\left(X\right)\right|$ where $N\left(X\right)$ is the neighborhood of $X$ and $max\{d\left(X\right):X?V\left(G\right)\}$ is called the critical difference of $G$. $X$ is called a critical set if $d\left(X\right)$ equals the critical difference and $\ker \left(G\right)$ is the intersection of all critical sets. $\mathrm{diadem}\left(G\right)$ is the union of all critical independent sets. An independent set $S$ is an inclusion minimal set with$d\left(S\right)>0$ if no proper subset of $S$ has positive difference.A graph $G$ is called a König–Egerváry graph if the sum of its independence number $\alpha \left(G\right)$ and matching number $\mu \left(G\right)$ equals $\left|V\left(G\right)\right|$.In this paper, we prove a conjecture which states that for any graph the number of inclusion minimal independent set $S$ with $d\left(S\right)>0$ is at least the critical difference of the graph.We also give a new short proof of the inequality $\left|\ker \left(G\right)\right|+\left|\mathrm{diadem}\left(G\right)\right|\le 2\alpha \left(G\right)$.A characterization of unicyclic non-König–Egerváry graphs is also presented and a conjecture which states that for such a graph $G$, the critical difference equals $\alpha \left(G\right)?\mu \left(G\right)$, is proved.We also make an observation about $\ker \left(G\right)$ using Edmonds–Gallai Structure Theorem as a concluding remark.     

一种动态评价法在钢铁企业低碳竞争力评价中的应用

在企业竞争力评价过程中,经常会遇到周期性、偶然性等问题,为解决这类问题,笔者在综合前人所提出“拉开档次”这一研究思路的基础上对TOPSIS法进行了拓展,并采用该方法对我国部分钢铁企业低碳竞争力进行了评价。研究结果表明,相对于现行的静态评价法,该法具有动态性、灵活性、综合性等优点,可以从各种角度反映钢铁企业的低碳竞争力状况。实证研究既验证了本方法的实用性和有效性,又解决了评价周期内巨大变化影响评价结论的问题,为企业低碳竞争力动态评价的研究提出了一种新的拓展思路。