简介:模型驱动架构(MDA)为软件开发提出了一种新的途径,MDA以模型驱动为核心,平台无关模型到平台相关模型的转换是MDA的关键技术。本文以MDA为基础,针对Web应用系统所包含的功能模型、对象模型、交互模型、界面模板、体系结构信息等五大块,提出了一种基于模型转换的代码自动生成技术,详尽描述了从高层模型到目标框架的映射关系,为基于J2EE平台的WEB应用提供了一种新的代码自动生成方法。
简介:BACKGROUND:Gliomaisthemostcommonintracranialtumorandhasapoorpatientprognosis.Thepresenceofbraintumorstemcellswasgraduallybeingunderstoodandrecognized,whichmightbebeneficialforthetreatmentofglioma.OBJECTIVE:Tousebibliometricindexestotrackstudyfocusesongliomastemcell,andtoinvestigatetherelationshipsamonggeographicorigin,impactfactors,andhighlycitedarticlesindexedinWebofScience.METHODS:AlistofcitationclassicsforgliomastemcellswasgeneratedbysearchingthedatabaseofWebofScience-Expandedusingtheterms"gliomastemcell"or"glioma,stemcell’"or"braintumorstemcell".Thetop63citedresearcharticleswhichwerecitedmorethan100timeswereretrievedbyreadingtheabstractorfulltextifneeded.Eacheligiblearticlewasreviewedforbasicinformationonsubjectcategories,countryoforigin,journals,authors,andsourceofjournals.Inclusivecriteria:(1)articlesinthefieldofgliomastemcellswhichwascitedmorethan100times;(2)fundamentalresearchonhumansoranimals,clinicaltrialsandcasereports;(3)researcharticle;(4)yearofpublication:1899-2012;and(5)citationdatabase:ScienceCitationIndex-Expanded.Exclusivecriteria:(1)articlesneedingtobemanuallysearchedoraccessedonlybytelephone;(2)unpublishedarticles;and(3)reviews,conferenceproceedings,aswellascorrectedpapers.RESULTS:Of2040articlespublished,the63top-citedarticleswerepublishedbetween1992and2010.Thenumberofcitationsrangedfrom100to1754,withameanof280citationsperarticle.Thesecitationclassicscamefromnineteencountries,ofwhich46articlescamefromtheUnitedStates.DukeUniversityandUniversityofCalifornia,SanFranciscoledthelistofclassicswithsevenpaperseach.The63top-citedarticleswerepublishedin28journals,predominantlyCancerResearchandCancerCell,followedbyCellStemCellandNature.CONCLUSION:Ourbibliometricanalysisprovidesahistoricalpersp
简介:Withthedevelopmentofwirelessnetworksandmobilecomputing,moreadvancedapplicationswithcontext-awarenessandadaptabilitytotheirchangingcontextareneeded.However,buildingcontext-awareapplicationsisdifficultduetothelackofadequateinfrastructuresupport.Inthispaper,awebmiddlewarearchitectureforthedevelopmentofcontext-awarenessapplicationsusingnearfieldcommunication(NFC)isproposed.Basedonit,theefficientsupportforacquiring,interpreting,andaccessingcontextisprovided,andtheuser’squalityofexperienceisimproved.Moreover,amobilewebmiddlewareforthetestingandfullrealizationofNFCcontext-awarenessapplicationshasbeendevelopedtogetherwithtwoapplicationexamples.
简介:多站点多种大气污染物的同步在线观测对深入剖析大气污染的成因和演变机制有重要意义。以龙潭湖、北京325m塔、双清路和阳坊4监测站点实时NOx、SO2、O3、PM2.5和PM10浓度观测数据为基础,介绍了北京地区2010年10月3~11日发生的一次典型污染过程。不同污染物在污染过程中变化特征不一致,表现为NOx、SO2、O3浓度有明显日变化,而PM浓度升高后一直维持在高值,日变化幅度很小。通过分析不同站点、相同污染物之间的相关性和变异系数发现,4站点间一次污染物NO和SO2空间浓度差别大,变异系数分别为77%和70%,相关系数低于0.44;而二次污染物NO2、PM2.5、O3空间浓度差别较小,变异系数分别为34%、36%和29%,相关系数均超过0.54。结合中尺度气象模式研究发现,该污染过程中,850hPa高空持续的西南暖平流造成华北地区显著平流逆温,与近地层辐射逆温共同作用,使北京地区混合层高度维持在1200m以下。低混合层高度和低风速限制了大气垂直和水平扩散,造成北京地区近地层污染物累积,形成重度污染。
简介:基于Web的实时监控系统是工业控制技术从集散型到现场总线之后的又一大进展,是网络技术和控制技术的融合应用,是全新的控制系统。随着Internet在各领域的渗透,借助Internet网络实现远程数据采集和实时控制意义深远。无线发射台站自动化是广电“十二五”规划工作重点之一,它助利于安全播出,获益于社会、经济双重效益。本文将以基于SNMP协议发射机监控系统的介绍为基础