简介:EfficientactivationofTlymphocytesthroughTcellreceptor(TCR)dependsontwosignals.Thefirstsignal(signalone)isderivedfromTCRinteractingwiththeMHC/antigenicpeptidecomplex,whichconfersantigenicspecificitytotheimmuneresponse.Thesecondsignal(signaltwo)isprovidedbytheengagementofTcellsurfacereceptorswiththeirspecificligandsonantigenpresentingcell(APC)[1].Asthereisgrowingevidenceforbidirectionalcommunicationsandsocalled“reversesignaling”fortraditionallydefinedligands,thedistinctionbetweenreceptorsandligandsbecomeslessclear.Thesepairsofmoleculesshouldbeviewedascosignalingmoleculesfunctioningincellswhichwouldexpresseitherthereceptorsortheligands.
简介:让Λ=kQ/I是有限维的Nakayama代数学,在Q是一个欧几里德几何学的图Yun徐舸电子邮件的地方:xuy@hubu.edu.cn参考书[1]。马克·莱恩,S.:相同,Grundlehren数学。Wiss。114,Springer,柏林,1975[2]。Happel,D.:有限维的代数学的Hochschildcohomology。在数学的讲课笔记,1404,108126(1989)[3]。Skowroński,A.:简单地连接的代数学和Hochschildcohomology。Proc。ICRAIV(渥太华,1992),能。数学。Soc。Proc,14,431447(1993)[4]。Assem,I.,delaPeña,J.A.:三角形的代数学的foundamental组。Comm。代数学,24,187208(1996)[5]。Gerstenhaber,M.:在戒指和代数学的变丑上。安。数学,79,59103(1964)[6]。Igusa,K.:笔记在上没有环推测。J。纯Appl。代数学,69,161176(1990)[7]。刘,S.X.,张,P.:截断的代数学的Hochschild相同。公牛。伦敦数学。Soc,26,427430(1994)[8]。Avramov,L.L.,Vigueé-Poirrier,M.:为光滑的Hochschild相同标准。Internat。数学。研究通知,1,1725(1992)[9]。汉,Y.:Hochschild(co)相同尺寸。J.伦敦数学。Soc,73(2),657668(2006)[10]。凯勒,B.:为DG代数学的周期的相同的不变性和本地化。J。纯Appl。代数学,123,223273(1998)[11]。Erdmann,K.,河边肥沃的低地T.:为班的self-injective代数学的扭曲的双性人模块和Hochschildcohomology一。论坛数学,11,177201(1999)[12]。Bardzell,M.J.,Locateli,A.C.,Marcos,E.N.:在截断的周期代数学的Hochschildcohomology上。CommAlg,28(3),16151639(2000)[13]。Assem,I.,Simson,D.,Skowroński,A.:联合代数学的表示理论的元素,伦敦数学。Soc。学生文章65,剑桥大学出版社,剑桥,2005[14]。Snashall,N.,Solberg,Ø.:支持变化和Hochschildcohomology
简介:用Co2(CO)8与CH3CSNH2反应制得产物Ⅰ,又用Na2Fe(CO)4与Ⅰ反应制得产物Ⅱ(Ⅰ:Co3(μ3-S)(CO)7(CH3CSNH),Ⅱ:Co2Fe(μ3-S)(CO)7(CH3CSNH).通过元素分析。IR、UV、1HNMR、MS表征并用X射线衍射法测得Ⅱ的单晶结构.该簇合物属三斜晶系、PT空间群,晶胞参数:a=0.9203(1),b=1.1296(2),c=1.1425(2)nm;α=116.40°(2),β=101.92°(2),γ=92.58°(1);z=2,V=1.2162nm3,Dc=1.698cm3,μ=21.89cm-1.结构分析表明,Co2FeS构三角锥分子骨架,所有CO均为端基配体,S1为面桥基配体,CH3CSNH为双齿配体,与Co、Fe形成五元环结构.
简介:采用金属粉型药芯焊丝自保护明弧焊制备Cr9Mn6Nb2WVSiTi奥氏体耐磨堆焊合金,借助XRD,SEM,EDS及光学显微镜研究外加WC颗粒对其显微组织及耐磨性的影响。结果表明,随焊丝药芯中WC增加,奥氏体晶粒细化,沿晶分布的多元合金化碳化物数量增加。初生γ-Fe相原位析出了(Nb,Ti,V)C相和残留WCx颗粒,起到晶内弥散强化作用,沿晶分布的(Nb,Ti,V)C和M6C(M=Fe,Cr,Mn,V,W)相隔断了网状或树枝状的沿晶M7C3相,使其细化、断续分布而提高合金韧性,减轻沿晶碳化物数量增加的不利影响。硬度和磨损测试结果显示,明弧堆焊奥氏体合金洛氏硬度仅为40~47,但其磨损质量损失低于高铬铸铁合金,具有良好耐磨性;随外加WC含量提高,奥氏体合金晶内和晶界显微硬度差异显著减小,合金表面趋于均匀磨损而改善耐磨性。该奥氏体合金的磨损机制主要是磨粒显微切削,适用于带有一定冲击载荷磨粒磨损的工况下使用。
简介:在Ni-Cr-B-Si基钎料中添加WC,添加量(质量分数)不超过30%。对胎体材料的硬度、抗弯强度和耐磨性进行测定,用扫描电镜观察胎体的表面形貌,并对不同区域进行能谱分析。结果表明,随w(WC)增加,胎体材料的硬度和耐磨性先增大后减小,在w(WC)为20%时,硬度达到最大值(123.8HRB),耐磨性最好,磨损量为0.221g。抗弯强度随w(WC)增加先缓慢下降,w(WC)超过20%后急剧下降。抗弯强度在1080~1220MPa之间,完全满足钻头对胎体抗弯强度的要求(抗弯强度值/〉700MPa)。胎体中WC颗粒由原始尺寸45~50μm减小到5μm以下,含WC的胎体材料出现较多的孔洞,钎焊层致密性下降。能谱分析表明,胎体材料中w元素与C元素没有同时出现,由此推断WC发生了相的转变;黑色区域为Ni、Fe、O的富集区,生成Ni与Fe的氧化物。
简介:TwopossiblereactionmechanismsofVS~+(~3∑~-,~1Γ)withCOinthegasphasehavebeenstudiedbyusingB3LYP/TZVPandCCSD(T)/6-311+G(3dr,3pd)methods:theO/Sexchangereaction(VS~++CO→VO~++CS)andtheS-transferreaction(VS~++CO→V~++COS).Thetworeactionsproceedviatwo-stepandone-stepmechanism,respectively.ThebarriersofthetripletandsingletPESsare30.6and50.9kcal/mol,respectively,forO/Sexchangereactionand7.3and50.2kcal/mol,respectively,fortheS-transferreaction.Theresultsindicatethatthetripletgroundstatereactionismorefavorable,andtheS-transferreactionismorefavorablethantheO/Sexchangereaction,whichisingoodagreementwiththeexperimentalobservation.
简介:
简介:ShandongHaihuaGroupCo.,Ltd..(hereinafterreferredtoasSHG)islocatedonthesouthernbankofLaizhouGulfintheBohaiSea,thenortheastofWeifang,acityrenownedastheworldkitecapital.EstablishedinAugust1995,onthebasisofitspredecessorsWeifangSodaAshFactoryandShandongYangkouSaltworks,SHGisanexceptionallylarge-sizedenterprise,
简介:ShaanxiAutomobileGroupCo.,Ltd.aimstorealizesustainabledevelopmentandactivelydevelopjointventureandcooperationwithforeigncompanies.Byadoptingsocialcapitalsinabroadway,bothitsscaleandproductioncapabilityhaveincreasedrapidlyandreachedanannualproductoutputof30,000heavy-dutyautomobiles,20,000mediumlorries,1,500buses(includingitschassis)and50,000heavy-dutytruckaxles.Inaddition,theannualproductionofitsradiator,oiltankandotherautopartsachieveRMB500millionproductionvalue.
简介:OnApril1,CAFIUworkedtogetherwiththeFriedrichEbertStiftung(FES)BeijingOfficeinhostingaRoundtablemeetingon"EnergyTransitionandSustainableEconomicPolicy".InvitedtoattendtheroundtablemeetingwereProf.Franz-JosefBr(u|¨)ggemeier,renownedGermansociologistandeconomist,Prof.LiHengyuan,formerDirector-Generalof
简介:<正>LetRbeanassociativeringnotnecessarilypossessinganidentityand(S,≤)astrictlytotallyorderedmonoidwhichisalsoartinianandsatisfiesthat0≤sforanys∈S.AssumethatMisaleftR-modulehavingproperty(F).ItisshownthatMisaco-HopfianleftR-moduleifandonlyif[MS,≤]isaco-Hopfanleft[[RS,≤]]-module.