机构知识库开源软件DSpace的扩展开发与应用   总被引：3，自引：0，他引：3  

祝忠明  马建霞  卢利农  李富强  刘巍  吴登禄 《现代图书情报技术》2009,(7)

对以DSpace原型系统为基础构建CAS-IR平台所进行的主要扩展和优化进行概述,主要涉及内容提交和编辑流程、知识组织、传播和服务、知识资产统计、用户管理、用户界面的优化以及面向生产环境的部署等方面的优化、改进或扩展,并对CAS-IR应用部署现状、扩展开发的经验进行简要总结.  相似文献   

TREC人机交互检索评价项目研究   总被引：1，自引：0，他引：1  

张秀坤 《图书情报工作》2006,50(1):72-75

介绍TREC交互项目的研究目标、试验设计、评价结果及其发展归宿。将TREC交互项目的发展划分为4个阶段,介绍各阶段在评价指标、试验课题等方面的变化,其中评价指标包括方面查全率、方面查准率、检索耗费时间及用户满意度等。从中可以发现,信息检索评价领域越来越注重“面向用户”的特征。  相似文献   

一种新的苯重氮氯化锌复盐的合成及结构     

杨青  杨靖鸣 《湖南师范大学教育科学学报》2000,(2)

以对苯二酚为原料,通过烷基化、溴化、硝化、还原、重氮化成盐等一系列反应合成了一种新的重氮光敏剂2,5-二丁氧基（4’-甲苯基硫代）苯重氮氯化锌夏盐,并通过元素分析,紫外可见光谱,红外光谱,核磁共振等手段对产物及中间体进行表征．  相似文献   

红外光谱法的应用     

周晓蕾  刘京生等 《保定师专学报》2000,13(2):19-21

介绍了近年来红外光谱法的一些新的应用。包括时间分辨红外光谱、二维红外光谱和近红外光谱。  相似文献   

蒙脱石—氯化铁红外光谱分析     

王仲军  张立萍 《唐山师范学院学报》2000,(2)

通过吡啶吸附红外光谱分析了蒙脱石(EC_1)、蒙脱石—氯化铁(EC_4(Ⅱ)、EC_4(Ⅲ)、EC_7、EC_9)特征吸收峰的相对强度。在EC_4(Ⅱ)、EC_4(Ⅲ)、EC_7、EC_9中,B酸1540cm~(-1)吸收增强,而L酸在1440cm(-1)吸收所占总酸量的比例下降。对于苯与氯化苄的反应,L酸1440cm(-1)附近吸收所占总酸量的比例越小,催化剂的催化性能越强。  相似文献   

Improving English and Chinese Ad-Hoc Retrieval: A Tipster Text Phase 3 Project Report   总被引：1，自引：1，他引：0  

K.L. Kwok 《Information Retrieval》2000,3(4):313-338

Both English and Chinese ad-hoc information retrieval were investigated in this Tipster 3 project. Part of our objectives is to study the use of various term level and phrasal level evidence to improve retrieval accuracy. For short queries, we studied five term level techniques that together can lead to good improvements over standard ad-hoc 2-stage retrieval for TREC5-8 experiments. For long queries, we studied the use of linguistic phrases to re-rank retrieval lists. Its effect is small but consistently positive.For Chinese IR, we investigated three simple representations for documents and queries: short-words, bigrams and characters. Both approximate short-word segmentation or bigrams, augmented with characters, give highly effective results. Accurate word segmentation appears not crucial for overall result of a query set. Character indexing by itself is not competitive. Additional improvements may be obtained using collection enrichment and combination of retrieval lists.Our PIRCS document-focused retrieval is also shown to have similarity with a simple language model approach to IR.  相似文献   

（五甲二硅基）环戊二烯基羰基卤——钼的红外光谱研究     

邝代治 《衡阳师范学院学报》1999,20(6):40-44

研究了三羰基（五甲二硅基）环戊二烯基羰基卤-钼［（η5-C5H4SiMe2SiMe5）（CO）3Mo－XX=Cl、Br、I]和（五甲二硅基）环戌二烯基双三苯基膦羰基溴钼[（η5-C5H4SiMe2SiMe5）（PPh3）2（CO）Mo—Br]以及二羰基（五甲二硅基）环成二烯基环氧亚成基卤钼{η5-C5SH4SiMe2SiMe5）（CO）2[CO（CH2）3]Mo－XX=Br、I}化合物的红外光谱,硅与茂环发生电子反馈作用表现在红外光谱振动吸收发生位移,从而讨论硅甲基取代环成二烯后对化合物的红外光谱的影响。并对标题化合物的主要红外吸收带进行归属。  相似文献   

肥胖、胰岛素抵抗与运动     

陈庆伟  刘丽华 《吉林体育学院学报》2008,24(3):90-91

大量研究表明胰岛素抵抗与多种疾病有着密切的关系,因此胰岛素抵抗被认为是当今影响人体健康的最主要代谢性疾病。肥胖与胰岛素抵抗（IR）有明显关系,证据已表明肥胖可以导致IR。IR被认为是当今影响人体健康的最主要代谢性疾病。在现有的防治手段中,长期运动锻炼是预防和治疗胰岛素非敏感性的重要部分。就近年来对肥胖、IR以及运动对其影响的研究加以综述。  相似文献   

The importance of cohesion and enjoyment for the fitness improvement of 8–10-year-old children participating in a team and individual sport school-based physical activity intervention     

Anne-Marie Elbe  Johan Michael Wikman  Miky Zheng  Malte Nejst Larsen  Glen Nielsen  Peter Krustrup 《European Journal of Sport Science》2017,17(3):343-350

This study investigates the enjoyment and cohesion of school children participating in a school-based high-intensity physical activity (PA) intervention. Both enjoyment and cohesion have been found to be important factors for adherence to regular physical and sport activity, an important outcome of PA interventions. The sample consisted of 300 pupils (mean age: 9.3 years; 52.7% female) assigned to a team sport intervention, an individual sport intervention, or a control group for 10 months. The Physical Activity Enjoyment Scale and Youth Sport Environment Questionnaire were used to measure enjoyment and cohesion. The Yo-Yo IR1C test determined fitness improvements. Results showed that enjoyment and cohesion (social) measured at the beginning of the intervention significantly predict fitness improvements achieved after 10 months. No differing developmental effects over time could be found in the intervention groups with regard to cohesion and enjoyment when comparing them to the control group. However, enjoyment and cohesion (social) significantly decreased in the groups that performed individual sports. Team sports seem to be more advantageous for the development of enjoyment and cohesion, which are both factors that positively impact the health outcomes of the intervention.  相似文献   

TournaRank: When retrieval becomes document competition     

Gilles Hubert  Yoann Pitarch  Karen Pinel-Sauvagnat  Ronan Tournier  Léa Laporte 《Information processing & management》2018,54(2):252-272

Numerous feature-based models have been recently proposed by the information retrieval community. The capability of features to express different relevance facets (query- or document-dependent) can explain such a success story. Such models are most of the time supervised, thus requiring a learning phase. To leverage the advantages of feature-based representations of documents, we propose TournaRank, an unsupervised approach inspired by real-life game and sport competition principles. Documents compete against each other in tournaments using features as evidences of relevance. Tournaments are modeled as a sequence of matches, which involve pairs of documents playing in turn their features. Once a tournament is ended, documents are ranked according to their number of won matches during the tournament. This principle is generic since it can be applied to any collection type. It also provides great flexibility since different alternatives can be considered by changing the tournament type, the match rules, the feature set, or the strategies adopted by documents during matches. TournaRank was experimented on several collections to evaluate our model in different contexts and to compare it with related approaches such as Learning To Rank and fusion ones: the TREC Robust2004 collection for homogeneous documents, the TREC Web2014 (ClueWeb12) collection for heterogeneous web documents, and the LETOR3.0 collection for comparison with supervised feature-based models.  相似文献