基于领域本体实现Web文本挖掘研究

为弥补改进传统Web文本挖掘方法缺乏对文本语义理解的不足,采用本体与Web文本挖掘相结合的方法,探讨基于领域本体的Web文本挖掘方法。首先创建Web文本的本体结构,然后引入领域本体“概念-概念”相似度矩阵,并就概念间关系识别进行描述,最后给出Web文本挖掘的实现方法,发现Web文本信息的内涵。实验中以网络媒体报道为例,通过文本挖掘得出相关结论。     

基于URI+RDF实现关系数据库数据发布

探讨如何将现有知识系统以URI+RDF模式进行发布以及关系数据与RDF模型之间的关系,分析关系模型转化为RDF的一般规则,并结合本体映射实现关系数据的URI+RDF描述。最后,以2010年上海世博会网络媒体报道分析课题的研究成果为例,分析将知识系统转换为URI+RDF描述进行发布的方法。     

Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc

Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:l was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane,decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.     

Optimal design of Stewart platforms based on expanding the control bandwidth while considering the hydraulic system design

We proposed an optimal design method to expand the bandwidth for the control of large hydraulic Stewart platform. The method is based on generalized natural frequency and takes hydraulic oil into consideration. A Lagrangian formulation which considers the whole leg inertia is presented to obtain the accurate equivalent mass matrix. Using the model, the effect of leg inertia and the influence of design parameters on the generalized natural frequency are investigated. Finally, numerical examples are presented to validate and confirm the efficiency of the mathematical model. The results show that the leg inertia, especially the piston part plays an important role in the dynamics. The optimum diameter ratio of the base to the moving platform is between 2 and 3, and the optimum joint angle ratio of the base to the moving platform is about 1. The smaller joint angles and a longer leg stroke are favorable for raising system frequencies. The system oil should be preprocessed for large platforms with a requirement for good dynamic performance.     

CALL教学中应当怎样注意网络交流中的礼仪问题

外语教学中非常注重学生跨文化交流能力的培养,计算机用于教学中以后,广大教师和学生经常地使用到电子邮件、键友、电子论坛、电子聊天、网络视频会议等等资源。因此,网络跨文化交流能力变得尤为重要。作为一名外语教师,特别是担负基础外语教学任务的外语教师,了解一定的网络交流礼仪是十分必要的。     

Optimization of conditions for supercritical fluid extraction of flavonoids from hops (Humulus lupulus L.)

Waste hops are good sources of flavonoids. Extraction of flavonoids from waste hops (SC-CO₂ extracted hops) using supercritical fluids technology was investigated. Various temperatures, pressures and concentrations of ethanol (modifier) and the ratio (w/w) of solvent to material were tested in this study. The results of single factor and orthogonal experiments showed that at 50°C, 25 MPa, the ratio of solvent to material (50%), ethanol concentration (80%) resulted in maximum extraction yield flavonoids (7.8 mg/g). HPLC-MS analysis of the extracts indicated that flavonoids obtained were xanthohumol, the principal prenylflavonoid in hops. Project (No. Y304203) supported by the Natural Science Foundation of Zhejiang Province, China     

Effects of fructose-1,6-diphosphate on concentration of calcium and activities of sarcoplosnic Ca^2＋-ATPase in cardiomyocytes of Adriamycin-treated rats

Objective: To observe the effects of fructose-1,6-diphosphate (FDP) on serum levels of cardiac troponin 1 (cTnl) and creatine kinase-MB (CK-MB), as well as the concentration of calcium in cardiomyocytes (Myo[Ca2 ]) and activity of sarcoplosnic Ca2 -ATPase (SRCa2 -ATPase) in Adriamycin (ADR)-treated rats. Methods: Rats were intraperitoneally injected with ADR (2.5 mg/kg every other day for 6 times) and then with different dosages of FDP (every other day for twenty-one times). Bi-antibodies sandwich Enzyme linked immune absorption assay (ELISA) was performed to detect serum level of cTnl. CK-MB was detected by monoclonal antibody, Myo[Ca2 ] was detected by fluorescent spectrophotometry and the activity of SRCa2 -ATPase was detected by inorganic phosphate method. Results: FDP (300, 600, 1200 mg/kg) significantly reduced the serum levels of cTnl and CK-MB, while at the same time decreased calcium concentration and increased SRCa2 -ATPase activity in cardiomyocytes of ADR-treated rats (P<0.01). Conclusions: FDP might alleviate the cardiotoxic effects induced by ADR through decreasing calcium level as well as increasing SRCa2 -ATPase activity in cardiomyocytes.     

“馆藏揭示+开放获取”模式下的专业性特色资源建设探究

文章结合天津高职院校图书馆基于"馆藏揭示+开放获取"的专业性特色资源数据库建设实践,就如何分析、梳理、提炼、整合、存储基于学校专业建设的馆藏信息资源以及如何挖掘、整合和利用具有专业特色的开放获取文献信息资源进行了探讨,旨在探索一条适合高职院校的专业性特色资源建设之路。     

一种非完整移动机器人开环迭代学习控制研究

针对非完整移动机器人的轨迹重复跟踪问题,提出了一种开环P型迭代学习控制算法。首先给出非完整移动机器人的运动学模型,并结合离散时域对轨迹跟踪问题进行描述,然后设计迭代学习控制器并在给定条件下证明了其收敛性;MATLAB仿真结果表明,随着迭代次数的增加,该算法能够有效改善动态不确定环境中系统的稳定性与收敛的快速性。     

面向职业技能发展的EPSS开发研究

EPSS是为了提高工作绩效利用计算机技术开发的一种电子绩效支持系统,这种系统具有信息集成性、工作情境性、学习自主性、知识共享性等特点。职工利用它既可以实现在工作中学习,又可以实现在学习中工作的职业教育功能。在EPSS逐渐成为促进职业技能发展,提高企业组织或个人绩效的干预措施之后,EPSS的开发成为实现职业教育功能和绩效支持的关键。乔尼(Nguyen)和沃尔(Woll)创建了一种EPSS开发模型,该模型从绩效角度和学习角度提出开发EPSS要经过绩效分析、EPSS分析、EPSS设计、EPSS开发、EPSS的实施与评价等几个阶段。乔尼和沃尔创建的EPSS开发模型将职工培训、工作绩效以及技术支持有效地融合于整个开发过程中,对设计、开发EPSS的实践者提供了一个简洁、便于操作的参考模型。