简介:引进分次Armendariz环的概念,讨论了分次环R=n∈ZRn及由它导出的非分次环R,R0,及R[x]之间关于Armendariz环性质的关系,并推广了[8]的结论,得到在R=n∈ZRn是Z-型正分次环的前提下,若R是分次Armendariz,分次正规环,则R是P.P.环(Baer环)当且仅当R是分次P.P.环(分次Baer环).
简介:AsoilpotcultureexperimentwithfoursuppliedPlevels(i.e.P30,P50,P100,P200,representingsupplementalP30,50,100,200mg/kg,respectively)wasconductedtoinvestigateuptakeanduseabilitytoPandZninthericegenotypeswithdifferentP-efficiency,ofwhichricegenotypes508,99011,580,99112werelow-Ptolerantand99056,99012werelow-Psensitive.Low-Ptolerantrice580and99011absorbedmorePthantheothers,andricegenotype580hadstrongeruptakeabilityespeciallyatlow-PlevelsuchasP50andP30.508couldabsorbconsiderableP,andhadthelowestPpercentageofshoot,indicatingithadgoodperformanceinP-useefficiency.ThesethreericegenotypeshadlargerbiomassandlessresponsetochangedPlevelthanricegenotype99112,99056and99012.Ricegenotype99112showedLow-Ptolerancemainlybysacrificingbiomasstomaintainhighrelativegrainyield.TheleastamountofPabsorbedby99056showedithadthelowestPuptakeefficiency,andthehighestPpercentageinshootof99012meantithadthelowestPuseefficiency.Sotheytwoshowedlow-Psensitivity.ZncontentsinshootunderP200,P100andP50weresimilar,butP30increasedZncontentinshootsignificantly.TheZncontentsinshootof99112,99056and99012werehigherthanthoseof508,99011and580,especiallyattilleringstageandbootingstage.AsfortotalZncontentinshoot,Low-Ptolerantricegenotype580hadthelargestamountandfollowedby99011and508,low-Ptolerantricegenotype99012hadthesmallestamountatthethreesamplingstageandfollowedby99056.Furthermore,P/Zninshootof99012wasthehighest,andthatof99056wasthesmallestatthesamePlevel.
简介:目的探讨风湿性心脏病行心脏瓣膜置换术患者,经冠状静脉窦逆行灌注对血清可溶性细胞间黏附分子(sICAM)-1、可溶性P-选择素(SPS)和心肌肌钙蛋白I(drnI)的影响。方法将56例风湿性心脏病行体外循环(CPB)下心脏瓣膜置换术患者随机分为两组:主动脉根部顺行灌注心肌停跳液(AC)组和持续经冠状静脉窦逆行灌注心肌停跳液(RC)组,每组28例。于6个时点采静脉血,检测sICAM-1、SPS和cTnI水平。结果CPB开始后,两组患者sICAM-1、SPS和cTnI水平均升高,术后8h达到峰值,但RC组峰值均低于AC组[sICAM-1为(817.9±133.2)μg/L比(901.1±132.0)μg/L,SPS为(83.46±16.24)pg/L比(107.82±19.68)μg/L,cTnI为(10.50±2.03)pg/L比(14.45±2.26)μg/L],且RC组回落速度快于AC组。结论逆行灌注能有效抑制sICAM-1、SPS和cTnI的表达,减轻炎性反应,从而起到更好的心肌保护作用。
简介:凭借着百分之二十左右的年化收益、保本保息且无投资门槛,P2P理财平台几乎令人难以抗拒。然而,随着P2P行业的高速发展,其隐藏的风险逐渐显露出来。今年上半年,爆出来多家P2P平台跑路的消息。
简介:Multimediastreamingservedthroughpeer-to-peer(P2P)networksisboomingnowadays.However,theend-to-endstreamingqualityisgenerallyunstableduetothevariabilityofthestateofserve-peers.Ontheotherhand,proxycachingisabandwidth-efficientschemeforstreamingovertheInternet,whereasitisasubstantiallyexpensivemethodneedingdedicatedpowerfulproxyservers.Inthispaper,wepresentaP2PcooperativestreamingarchitecturecombinedwiththeadvantagesofbothP2Pnetworksandmultimediaproxycachingtechniquestoimprovethestreamingqualityofparticipatingclients.Inthisframe-work,aclientwillsimultaneouslyretrievecontentsfromtheserverandotherpeersthathaveviewedandcachedthesametitlebefore.Inthemeantime,theclientwillalsoselectivelycachetheaggregatedvideocontentsoastoservestillfutureclients.Theassociateprotocoltofacilitatethemulti-pathstreamingandadistributedutility-basedpartialcachingschemearedetailedlydis-cussed.Wedemonstratetheeffectivenessofthisproposedarchitecturethroughextensivesimulationexperimentsonlarge,Inter-net-liketopologies.
简介:SomecharacterizationsoftheconditionalexpectationoperatorsonLebesgue-BochnerspacesL_p(μ,X)aregiven,where1≤p<∞,p≠2.AlsoanexampleisgiventoshowthatthecharacterizationsoftheconditionalexpectationoperatorsonL_p(μ,X)aredifferentfromthatonL_p(μ)_zFinally,arepresentationoftheconstant-preservingcontractiveprojectiononspacesL_p(μ,X)isgotwhen0<p<1.