简介:Treatmentof4-amino-3-(1-aryl-5-methyl-1,2,3-triazol-4-yl)-5-mercapto-1,2,4-triazoles/2-amino-5-(1-aryl-5-methyl-1,2,3-triazole-4-yl)-1,3,4-thiadiazoleswithbenzaldehyde,acetoneandω-bromoacetophenonewastestedandcompared.ThetitlecompoundsSchiffbases,amides,imidazolo[2,1-b]-1,3,4-thiadiazolesand7H-s-triazolo[3,4-b]-1,3,4-thiadiazineshavebeenconfirmedbyelementalanalyses,^1HNMR,IRandMSspectra.AllthecompoundshavealsobeenscreenedfortheirantibacterialactivitiesagainstB.subtilis,S.aureusandE.coli.
简介:Asimplemethodisappliedtocalculatingtheisotopeshifts(ISs)on5S1/2→4D3/2,5/2transitionsof87,88Sr+.FirstwehavecalculatedtheISsoflowertransitionsonaseriesofalkali-likesystemssuchasB2+,Ca+andBa+,whichareinagreementwithotherworks.ThentheISson5S1/2→4D3/2,5/2transitionsof87,88Sr+,whichareusefultostudytheSr+opticalfrequencystandard,areevaluated.
简介:贵刊2004年第3期在《问题·争鸣》栏里登载了戴、代二位老师的《“1:2”不能写成“1/2”吗》一文,认为1:2可以写成1/2。2005年第二期又刊了王老师的《也谈“1:2”与“1/2”》一文,他认为,比就应写成“1:2”的形式,而�
简介:STUDYONTHEREARRANGEMENTREACTIONOF5-AMINO-1-AMINOCARBONYL-1,2,ANDITSANALOGUES¥RongJianLU;HuaZhengYANG;BaoYingQIAN;HaiYanDENG(N...
简介:二次根式(a~2)~(1|2)和((a~2)~(1|2))有什么区别吗?主要表现在下面三个方面:1.读法不同.(a~2)~(1|2)读作根号a的平方,而((a~2)~(1|2))读作括号根号a括号的平方.2.表示的意义不同.(a~2)~(1|2)是求a~2。的算术平方根.((a~2)~(1|2))求的是a的算术平方根的平方.一个表示求一
简介:Thetitlecomplex,[La(baec)1/2(H2btec)1/2(H2O)]n(H4btec=1,2,4,5-benzenetetracarboxylicacid)(1)wassynthesizedbythehydrothermalreactionof1,2,4,5-benzenetetracarboxylicdianhydridewithLa(NO3)3·6H2OinH2O,andcrystallizesinthetriclinicsystem,spacegroupP-1withα=0.64403(3)nm,b=0.94500(4)nm,c=0.96380(5)nm,α=88.535(2)°,β=100.314(2)°,γ=76.6470(10)°,V=1.69968(10)nm^3,Z=2,andfinalR=0.0274,Rw=0.0735.In1,eachLa(Ⅲ)ioniscoordinatedbyeightoxygenatomsfromsixcarboxylategroupsandonecoordinatedwatermolecule.TwodifferentcoordinstionmodesofH4btecwerePresentinthestructure,oneofwhichcontainstwoprotonatedcarboxylategrougpstobalancethecharge.
简介:Polymer-supportedRCpCpTiCl2(Cp=η^5-C5H4;RCp=η^5-RC5H4)havebeenpreparedandreducedbyi-C3H7MgBrinsitu,thenusedincatalyticisomerizationof1,5-hexadiene.Theisomerizationof1,5-hexadieneleadstoamixtureofcyclicandlinearproducts.Theratioofcyclictolinearproductdependsonthenatureofthesupporterandthesubstituentonthecyclopentadienylring.Theformercontributesthemost,forexample,silicasupportedCp2TiCl2gavecyclic-linearratioof99/1,whileforpolymer-supportedCp2TiCl2species,linearcompoundsarethemajorproductsandtheratioofcyclictolinearproductchangeswithdifferentRgroupsonthecyclopentadienylring.