简介:Inanattempttoassessthepaleoenvironmentsofterrestrialsediments,sometwenty-tworepresenta-tiveChinesenon-marinesedimentsampleswerestudiedusingthemolecularorganicgeochemistrymethod.Thesedimentsamplesstuiedincludeoilshale,shale,mudstoneandglaubersaltfromTertiarytoCretaceousinage.Judgingfromgeological/geochemicaldataandpaleosalinitydata,thesamplesstudiedareoflacustrinesedimentaryoriginandcanbedividedintothreedifferenttypes:freshwater,brackishandsaline/hypersalinelakesediments.ThealiphaticfractionswereseparatedfromtheextractsofthesamplesandanalysedbymeansofGCandGC/MSinstruments,givinganumberofparameterssuchasrelativeabundancesofalkanesandcycloalkanesasshowninthemasschromatograms.
简介:Thecarbynecompound[Br(CO)2(Py)2Mo(≡CC6H5)](Py=pyridine)(1a)reactswithCo2(CO)8,Fe2(CO)9andMn2(CO)10togivetetrahedraltri-metalclustercompoundsCo2Mo(μ3-CC6H5)Br(CO)8(Py)2(2),Fe2Mo(μ3-CC6H5)Br(CO)9(Py)2(3)andMn2Mo(μ3-CC6H5)Br(CO)10(Py)2(4)respectively.Tri-metalclustercompoundCo2Mo(μ3-CC6H5)Br(CO)8-(bipy)(bipy=α,α’dipyridyl)(5)ispreparedinasimilarreactionsequencefrom[Br(CO)2(bipy)Mo(≡CC6H5)](1b)andCo2(CO)8.IR,1Hand13CNMRspectraldataofthesecompoundsarereportedanddiscussed.Thecrystalstructureofcompound(5)hasbeendeterminedbyX-raydiffraction.
简介:Inthetheorycalculationoflatticevibration,oneacousticandthreeopticalbrancheswerefoundtocomposethephononvibratingspectrum.Someisolatedmodeswithfrequencieslyingoutsidethecontinuumbrancheswillariseunderthedefectstates.TheselocalmodelresultsinthesharppeaksintheinfraredabsorptionandRamanspectra.Fromcalculationoftheinfraredabsorption,thelocalmodewiththeinfraredactivityisobtainedintheinfraredabsorptionspectrumofMXcompounds.
简介:在土壤的芳香的混合物(交流)能为土壤NH3氧化导致竞争抑制,并且氮的硝化作用禁止者能习惯于这个目的。一个实验室孵化实验与12nitroaromatic混合物(NAC)被执行,15amidoaromatic混合物(AAC)和20hydroxyaromatic混合物(HAC)到在土壤上估计交流的禁止的效果氮的硝化作用。把结果基于这些,交流的批评、最佳的集中为更好禁止的效果被决定。大多数测试交流能禁止土壤氮的硝化作用;有效性与土壤类型不同。在交流之中,有m-nitryl的NAC,氨基或与芳香的戒指上或与p氢氧根的一个nitro组或一个氯原子一起的氢氧根和AAC是更有效的。3硝基苯胺,4-aminophenol和3-nitrophenol作为氮的硝化作用禁止者显示出最大的潜力。在棕色的土壤和黄棕色土壤的这些混合物的批评集中被发现是0.5mgkg?1土壤。由于交流的毒性,致癌性和mutagenicity,进一步毒物学并且在交流在农业、园艺的惯例被用作氮的硝化作用禁止者以前,ecotoxicological研究是必要的。
简介:Selenium(Se)isanessentialtraceelement,whichhumansandanimalstakedirectlyorindirectlyfromplants.Thispaperreviewedtherecentresearchprogressonspeciationofseleniumcompoundsinplants,includingthekindsofseleniumcompoundsandtheirmetabolicpathways,andthetechnologyforsampletreatment,separation,anddetermination.Organicseleniumcompoundsarethemajorpartsoftheseleniumspeciationinplants.Thetechnologyofultrasonic-microwavesynergisticextractioncombinedwithenzymatichydrolysisisusefulinsamplepreparation.HPLC-ICP-MSiswidelyusedindeterminingseleniumspeciation.Itisimportanttodevelopmorestandardseleniumcompoundsandpaymoreattentiontoselenoproteininplants.ESMS,ESMS-MSandMALDI-TOFcanbeappliedtoidentifyingtheunknownseleniumcompounds.TheapplicationofIDAindeterminingboththemetabolicpathwaysandthestructureoflargeseleniummoleculeswillbeamajoraspectforthefutureresearch.
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简介:Allplantsemitawiderangeofvolatilecompounds,theso-calledbiogenicvolatileorganiccompounds(BVOC).BVOCemissionshavereceivedincreasedscientificattentioninthelasttwodecadesbecausetheymayprofoundlyinfluencethechemicalandphysicalpropertiesoftheatmosphere,andmaymodulateplanttolerancetoheat,pollutants,oxidativestressandabioticstresses,andaffectplant-plantandplant-insectinteractions.Urbanforestrymayhaveahighimpactonatmosphericcomposition,airquality,environment,andqualityoflifeinurbanareas.However,fewstudieshavebeencarriedoutwheretheemissionofBVOCcouldhaveimportantconsequenceforthequalityofairandcontributetopollutionepisodes.AscreeningofBVOCemissionbythemixedstandconstitutingurbanforestsisthereforerequiredifemissionsaretobereliablypredicted.Monitoringtheemissionratessimultaneouslywithmeasurementsofairquality,plantphysiologyandmicrometeorologyonselectedurbanforests,willallowdetailedquantitativeinformationontheinventoryofBVOCemissionsbyurbanvegetationtobecompiled.Thisinformationwillmakeitpossibletoproposeaninnovativemanagementofurbanvegetationincitiescharacterisedbyheavyemissionsofanthropogenicpollutants,aimingattheabatementofBVOCemissionsthroughtheintroductionorselectionofnon-BVOCemittingspeciesinurbanareassubjectedtopollutionepisodesandinthenewafforestationareascoveringperi-urbanparks,greenbeltsandgreencorridorsbetweenperi-urbanruralareasandtheconurbations.
简介:Refractorycompoundsarematerialwithinterestingpropertiesforstructuralapplications.However,theprocessingofsuchmaterialisagreatchallengebecauseoftheirhighmeltingtemperatureandlimitedductility.Mechanicalalloyingisanoveltechniqueofproducingrefractorycompoundswithspecificproperties.Kineticalandstructuralpeculiaritiesofrefractorycompoundsandalloysobtainedbymechanicalalloyingarediscussed.
简介:Cancerisgenerallyregardedastheresultofabnormalgrowthofcells.AccordingtoWorldHealthOrganization,canceristheleadingcauseofmortalityworldwide.Mothernatureprovidesalargesourceofbioactivecompoundswithexcellenttherapeuticefficacy.Numerousphytochemicalsfromnaturehavebeeninvestigatedforanticancerproperties.Inthisreviewarticle,wediscussseveralnaturalcompounds,whichhaveshownanti-canceractivity.Naturalcompoundsinducecellcyclearrest,activateintrinsicandextrinsicapoptosispathways,generateReactiveOxygenSpecies(ROS),anddown-regulateactivatedsignalingpathways,resultingininhibitionofcellproliferation,progressionandmetastasisofcancer.Severalpreclinicalstudieshavesuggestedthatnaturalcompoundscanalsoincreasethesensitivityofresistantcancerstoavailablechemotherapyagents.Furthermore,combiningFDAapprovedanti-cancerdrugswithnaturalcompoundsresultsinimprovedefficacy.Onthebasisoftheseexcitingoutcomesofnaturalcompoundsagainstseveralcancertypes,severalagentshavealreadyadvancedtoclinicaltrials.Inconclusion,preclinicalresultsandclinicaloutcomesagainstcancersuggestpromisinganticancerefficacyofagentsfromnaturalsources.
简介:在FCC汽油的硫混合物的形成上的石蜡的效果在在从400~500的温度联合起来的一张小规模的固定的使流体化的床(FFB)上被学习,重量时时10h-1的空间速度(WHSV),和6的催化剂/油比率。结果证明在FCC汽油包含的C4-C6石蜡能与H2S反应主要形成thiophenes,alkyl-thiophenes以及thiols的部分数量,当象heptene那样的大分子的石蜡能与形成benzothiophenes的氢硫化物反应时。在不同催化剂上在不同温度形成的硫混合物的数量与在化工物品的石蜡的集体部分成比例,与在REUSY催化剂超过上形成的硫混合物的数量,那些在石蜡变换的度上由于催化剂性能的效果和催化剂的影响在形状上形成了选择沸石催化剂。因为为硫的形成的热力学、运动的常数上的温度的影响,在450点的最大值和在400点的最小象在石蜡变换degree.Based上一样加重在上的产生的硫混合物和他们到达的增加的数量上述学习,为与H2S在FCC汽油在石蜡的反应之上产生的硫混合物的预言的一个反应网络和一个模型被建立。
简介:Difluorocarbenegeneratedfromthedecompositionoffluorosulfonyldifluoroaceticacid(2)reactedwithvarioussodiumsaltsofN-heterocycliccompounds(1)givingthecorrespondingdifluoro-methylatedproductsinacetonitrileat10—40℃.Benzotriazole(1a),benzimidazole(1b)andimidazole(1c)wereconvertedinto1-(difluoromethyl)benzotriazole(3a),1-(difluoromethyl)benzimidazole(3b)and1-(difluoromethyl)imidazole(3c)respectively.Indole(1d)reactedwith2togive-(fluorosulfonyldifluoro-acetate)indole(2d)ratherthantheexpecteddifluoromethylatedderivatives.
简介:Introduction TheheteropolyanionphasetransferchemistrycreatedbyPopeM.T.In1984hasopenedupanewfieldforheteropolycompoundresearch[1-3].Butsubstitutingcoordinationwatermoleculesbyorganicopticallyactiveligandhasnotbeenreportedinliteraturesuntil1997[4].