简介:20(R)—Rh2是一种次生甙,是红参的特有成分。日本学者研究发现,20(R)—Rhc是一种高活性的抗癌成分,具有独特的逆转作用,但由于红参中含量甚微,直接提取利用得不偿失,极大地限制了20(R)—Rh2的应用开发。吉林人参研究所陶丽华课题组的全体人员,经过八、九年的研究探索,又取得了新的成就。一九八七年他们采用人参地上部分以其中的二醇型人参皂甙为前体物质,利用化学转化方法进行化学结构的修饰改造,最终得到Rh2的纯品。经理化常数测定及13C谱检测,由沈阳药科大学徐绥绪教授确认为20(R)—Rh2。由此,为我国首次采用工业化方法生产人
简介:ThispaperhighlightstheresearchanddevelopmentactivitiesbeingdoneonurbanforestryinthePhilippines.TherolethatR&Dplaysinurbanforestryislikewisediscussedintheintroduction.Recommendedtreespeciesforurbanplantingarepresentedincludingtheircharacteristicsanddistribution.Researchesrelatedtourbanforestrybeingconductedarelistedwithashortdescriptionofeachproject.Developmentactivitiesonurbanforestryarelikewisediscussed.Finally,recommendedR&DagendaandresearchableareasbasedonthePhilippineAgenda21andtheDepartmentofEnvironmentandNaturalResources(DENR)R&DFrameworkarepresented.
简介:ThehistoricaltransitionoftimberdistributionpatterninChinawaspresentedfirstlywithmainpartsoftimberflowsinChina,whichincludedtimbermarkets,timbertransportsystemandregulationsoftimbertransport.BasedontheoverviewontropicaltimberflowsinChina,thetradeflowsoftropicaltimberfromproductionandimportsoftropicaltimbertoexportoftropicaltimberproductswereanalyzedbyvividillustrations.Atthesametime,problemsintimbertradeflowsinChinawereanalysedintheend.
简介:Inaviewofnaturalconditionsofestablishingnaturereserve,anindexsystemwaspreparedforquantitativeassessmentonstatusofendangeredspecies,andthusdegreeofendangeredspeciesinTibetwasevaluated.Takingasub-ecozoneasbasicunit,top5animalsand1plantwithhighEaswellasthenumberofspeciesineachunitwereenumerated;andthedegreeoflandutilizationwasfiguredout.Afterward,weselected6coefficients,assignedweight,andframedformulatoreckonproportionofnaturereserve,thusanareaofnaturereserveineachsub-ecozonewasobtained.In5schemesofweightassignment,aschemewithmediumareaofnaturereservewasselected.Allsub-ecozoneswereclassifiedinto4gradespriorconservation,1wasingradeA,2ingradeB,2ingradeC,and11ingradeD.Totalplannedareawasapproximately365135km2,about48834km2smallerthantheactualareaof413969km2,ratioofnaturereserveinTibetdiminishesfrom34.4%to30.38%.Basedon3factorsofhumandisturbance,ratioofbuffer-experimentalzoneinproposednaturereservewascalculated.Itwasdemonstratedthatexistingsizeofnaturereservesisexcessiveonthewhole,andtheirdistributionisnotreasonableentirely.Thesizeofnaturereservesin3sub-ecozonesofnorthernChangtangshoulddecrease,anddecrementofareaisapportionedamongother13sub-ecozoneswhichshouldincreasenaturereserve.HeterogeneityofregionaldistributionofrarespeciesinTibetisquiteobvious,soproposedareadistributionofnaturereservesismorescatteredthantheexisting.
简介:KafangTownship,XinxianCountyofHenanProvinceislocatedinthehinterlandoftheDabieMountainborderingHenanandHubeiprovinces.Thistown...
简介:Cd忍耐和米饭幼苗的translocation上的H2O2预告的处理的效果用在Cd忍耐不同的二米饭栽培变种(N07-6和N07-63)被学习。malondialdehyde(MDA)的内容,减少的谷胱甘肽(GSH),非蛋白质thiols(NPT),phytochelatins(PC)和谷胱甘肽S-transferase(GST)的活动在暴露于各种各样的处理的二栽培变种之间被比较。结果证明50mol/LCd暴露显著地禁止了米饭生长,提高了GSH,NPT,PC和MDA的生产,并且增加了GST的活动,并且二栽培变种之间有重要差别。更多的Cd被搬运进N07-6的射击。H2O2预告的处理由进一步在根增加GSH,NPT和PC内容,以及GST活动减轻了Cd毒性。在N07-63的这些参数的增加度比在N07-6的那些高,建议N07-63的忍耐比N07-6更显著地被提高。氢过氧化物把Cdtranslocation归结为米饭射击,但是不同地在根影响了Cd内容。从上述结果,在到在二栽培变种之间的H2O2预告的处理的Cddetoxification和反应有显著差别,这可以被推测。
简介:TheadsorptionkineticsofPb^2+ondifferentsoilsandmineralswithvariablechargeswasstudiedbythetwoion-selectiveelectrodetechniqueatdifferentpHandconcentrations.Theresultsshowedthatmorethan95%ofadsorptiononallthesamplesoccurredduringthefirst5minutes.Alladsorptiontime-dependentdatacouldfitthesurfacesecond-orderequationverywell.ThevaluesofXmweregoethite>kaolinite,andlatosol>redsoilatthesameinitialreactionconcentration.Thevaluesofkwerekaolinite>>goethite,andlatosol>redsoilatthesamereactionpHandinitialconcentration.ThehigherthesuspensionpH,thefastertheadsorptionoccurred.ThemeaningofXmgotbythetwoion-selectiveelectrodetechnique(onekindofbatchtechnique)wasdifferentfromthatbythemiscibledisplacementtechniqueinthattheformerwasonlytheequilibriumadsorptionamountatadefiniteconcentrationandpH,butthelatterwasalmostequaltotheadsorptioncapacityatadefinitepHwithmuchlessinfluenceofconcentration.OnePb^2+wassupposedtooccupytwoadsorptionsitesastheadsorptionmechanismisconcerned.