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简介：Reactionsofthe6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrilederivative1withα-halo-carbonylcompoundsgavetheortho-substitutedintermediates2a-cwhichwereconvertedintofuro[2,3-b]thiopyrano[4,3-d]pyridines3a-cbyfusionofafuranmoietyunderbasicconditions.Furthercyclizationof3a-cledtoafusionofapyrimidinering,yieldingthetetracyclicproducts6,7and8.Inaddition,condensationof6withvariousaromaticaldehydesaffordedthecorrespondingimines9a,b.Mannichreactionof7gaveproducts10a,b.

简介：3,5,6,8-Tetrahydro-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4-ones(7)weresynthesizedviathebasecatalyticreactionsofaminesorphenolswithcarbodiimides(5),whichwereobtainedfromtheaza-Wittigreactionsofiminophosphoranes(4)witharomaticisocyanates.

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.

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简介：梦想过征服太空的朋友请注意,前往太空的“火箭”即将发射,请做好准备!太空冒险是许多人儿时的梦想,瑞士著名钟表实验室MB＆F的创始人MaximilianBüsser也有-场太空梦,于是他脑洞大开,和瑞士老牌家族企业Carand’Ache联手打造了-款火箭造型的钢笔——Astrograph.

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简介：在有ArSSAr的THF的SmI2的反应生产了二binuclear钐thiolate建筑群[(THF)3I2-Sm(-SAr)]2[Ar=Ph(1)，4-Me2NC6H4(2)]在高收益。2的结构被单个水晶X光检查晶体学描绘。2的水晶与空格组和a=0.95705(13)一起属于三斜晶系的系统nm，b=1.22287(14)nm，c=1.26450(14)nm，=64.194(11)??匭吗？？v？？

简介：Thesynthesisof(S)-2-(3-arylacrylamido)-3-{4-[2-(5-methyl-2-phenyloxazol-4-yl)ethoxy]phenyl}propanoicacidsisdescribed.TheirstructureswereconfirmedbyH-NMR.

简介：美国旧金山的金门大桥跨越1900多米的金门海峡，连接起北加利福尼亚与旧金山半岛，大桥建成通车后，大大节省了两地往来的时间。但是新问题随之出现，由于出行车辆很多，金门大桥总会堵车。

简介：l、2、3、4——四只小羊齐步走左、右，左、右——齐步走

简介：Lactivicin,anovelinhibitorofbacterialcellwallsynthesis,wasisolatedfromtheculturefil-tratesofmicroorganismYK-258andYK-422.Itexhibitsbiologicalactivitiessimilartothoseoftheβ-lactamantibiotics,althoughitdoesnothaveaβ-lactamringinitsmolecule.Sincethediscoveryoflactivicin,hundredsofitsderivativeshavebeensynthesized.Most

简介：Methetraxate(MTX),aclassicaldihydrofolatereductaseinhibitor,wasasuccessfulclinicalantitumoragent,havingpotentinhibitoryactivitiestoseveralkindsoftumors.Unfortunately,thecancercellkswereeasiertoproduceresistancetoMTXwhichendedinthefailureofchemotherapy.Inordertoovercometheresistanceoftumorcells,anewkindofdihydrofolatereductaseinhibitorscallednonclassicalantifolateincludingtriazines,pyrimidinesandquinazolinesweredesignedandsynthesized.Becauseofthedifferentantitumormechanismsbetweenthetwokindsofcompunds,thecancercellsresistanttoMTXmaystillbesensitivetothenonclassicalantifolate.Accordingtothistheory,somenonclassicalantifolate2,4-diamino-5-methyl-6-(substitutedbenzylamino)quinazolineswiththegeneralstructureshowninFIg.1weresynthesizedandtheirantitumoractivitiesweredeterminedinthisthesis.

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简介：利用水热法首次合成了具有两种配位环境Cd原子的新型杂多蓝化合物[NH3（CH2）2NH3]5[Cd（H2O）][CdMo12^vO30（HPO4）6（H2PO4）2]·5H2O．通过元素分析、ICP、TG和X射线单晶衍射确定了其组成，使用IR和EPR进行了结构表征．通过N2吸附脱附测定了比表面积和孔径，为催化研究提供了基础数据．结果表明：该晶体为三斜晶系，P-1，空间群；晶胞参数a=1．2002（2）nm，b=1．4651（3）nm，c=2．1192（4）nm，V=3．5642（12）nm^3，p=83．01（3）°，Z=2，F（000）=2932，R1=0．0300，wR2=0．0716．

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：以2,6-二甲基苯酚、氧气为原料,氨水与乙酸铜为催化剂,合成得到了3,3′,5,5′-四甲基-4,4′-联苯二醌,得到反应的最佳条件为:2,6-二甲基苯酚的浓度为0.1g/mL,氨水与乙酸铜的摩尔比为0.43,温度为75℃,反应时间为6h,产率达到60%.

简介：摘要高压加热器（简称高加）是给水系统的重要设备，其性能和运行的可靠性将直接影响机组的经济性以及安全性，姚孟#5/6机两台600MW机组#3高压加热器在运行中管束频发故障，导致高加退出运行，造成机组的安全性及经济性下降。本文对高压加热器泄漏的危害、原因、以及高加泄露后的处理方法进行了整体分析。