简介：运用转移矩阵的技巧,本文给出了戴帽B27N27硼-氮zlgzag纳米管的克库勒结构数的计算公式.在实际计算中,根据管的对称性,转移矩阵的阶得到了显著地降低.

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简介：Inthepresentwork,theLEDchipwasirradiatedbyusing59.6MeVNionsinaterminalchamberoftheSector-focusedcyclotron(SFC)intheNationalLabortaryofHeavy-ionAcceleratorsinLanzhou.The63MeVNionspenetratedthroughagoldfoilandscatteredinalargearea.Theenergyofionwasreducedto59.6MeVafterscatteringofthegoldfoil.TheLEDwasprovidedbytheSemiconductorLightingCenterinInstituteofSemiconductorinBeijing.TheluminencesoftheLEDbefore/afterirradiationweretestedthroughaintegratingsphereinSemiconductorLightingCenterinInstituteofSemiconductorinBeijing.Theluminancewastestedunderacurrentof350mA.Fig.1showstherelationshipbetweentheluminencesandtheirradiationfluences.Theirradiationledto

简介：Solidstatenanoporesornanochannelspreparedinpolymer[1;2]andsemiconductorfilms[3]haveshowninterestingtransportphenomena,becauseoftheirdiametersatthenanoscaleandpositiveornegativechargesontheirwalls.Grapheneisanidealmaterialfordevelopingsolidstatenanoporesnotonlyduetoitsatomicscalethickness,highmechanicalstrengthandchemicalstabilitiesbutalsobecauseoftheimpermeabilityofthepristinesinglelayergraphenetoallatomsandmoleculesexceptprotons[4].AsthesingleGraphene/PET(G/PET)nanoporeistheelementarybuildingblockfornanoporousmembrane,theunderstandingandcontrolofitsindividualionictransportpropertiesarealsocrucialinproteinseparation,waterdesalination,andbio-moleculedetectionusingarraysofidenticalnanopores.Here,thesingleG/PETnanoporewassuccessfullypreparedbyusingionirradiationtechnologyandasymmetricetchingmethod[5]andthecorrespondingionictransportpropertieswereinvestigatedindetail.

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简介：使用代数数论和p-adic分析，我们找到了椭圆曲线y^2=x^3＋27x-62上所有的整数点．我们给出了一个全虚四次域的子环上计算基本单位和二次代数数“不相关分解”的方法．

简介：AngulardistributionsoffragmentsB,C,N,O,F,Ne,Na,MgandAlinducedbythecollisionof^19F+^27Alat114MeVhavebeenmeasured.Angulardispersionparametersareextractedfromtheexperimentaldataandcomparedwiththetheoreticalones.ThedynamicdispersionsfordissipativeproductsdependstronglyonthechargenumberZofthefragments.

简介：结合国内外各课题组研究，从27纨A1NMR实验参数和铝形态研究两方面综合评述了液体27A1NMR的发展研究现况。首次明确提出27A1NMR测定中设置合适的预采集延迟时间的作用。将为进一步开展的277A1NMR测定研究提供有价值的参考。

简介：TheinteractionprocessofionsandplasmasisanimportanttopicinIon-Beam-DrivenHighEnergyDensityPhysicsandInertialConfinementFusionresearch.Duetothestrongnon-lineareffectsandthespecialimportanceinICFresearch,moreandmoreemphasishasbeengiventotheinvestigationsforionbeaminlowenergyrangeand/orforplasmawithhighintensity[1;2].Here,weaddressthenewlymeasuredresultsoftheenergylossbyslowionspenetratingthefullyionizedhydrogenplasmatarget.

简介：Inthepaper,thenonlinearmagnetoelasticpropertiesofcompositionTb0.27Dy0.73Fe1.95<110>orientedpolycrystallinealloysareinvestigatedundercoupledloadsofhighmagneticfieldandcompressivestress.Themagnetizationandmagnetostrictionaremeasuredsimultaneouslyunderappliedmagneticfieldfrom800to800kA/mandcompressivestressfrom0to25MPaatroomtemperature.Thestraincoefcientandrelativepermeabilityareobtainedbydiferentialcalculationfromtheexperimentalcurves.Theresultsshowthatthevaluesofsaturationmagnetization(Ms)underdiferentcompressivestressesremaininvariablyconstantintheregionofthehighmagneticfield.Thesaturationmagnetostriction(λs)increaseswithincreasingcompressivestressandreaches1680×106under25MPa.Accordingtotheincreaseofthecompressivestress,thehystereticloopareaofmagnetizationandmagnetostrictionincreases,whilethemaximumrelativepermeabilityandstraincoefcientdecrease.Additionally,theinfluenceofthebiasmagneticfieldonthemechanicalpropertyistakenintoaccount.Thestress-strainrelationshipisnonlinearandsensitivetotheappliedexternalmagneticfieldsalongtheaxisofrod.Theresultsobtainedareausefulcomplementtotheexistingexperimentsfortheoreticalapproachesandengineeringapplications.

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简介：选用30个结构多样的CaM抑制剂分子作为数据集，采用多元线性回归（MLR）方法及主成分回归分析（PCA）方法对每个化合物的194个分子参数进行回归分析，分别建立了各自的最优预测模型．结果表明：多元线性回归分析方法所建模型与主成分回归所建模型相对比，发现逐步筛选法为最优建模方法．该方法所建模型统计结果良好（R^2=0．952，SEE为0．289），应用于检验集时结果也比较令人满意（R^2=0．941，SEP为0．295），模型表现出较强的可靠性和预测性．

简介：江苏省2009年中考物理试卷第27题是以探究环形磁体的磁极为背景材料，着重考查通过各种途径鉴别猜想真伪的能力．该题是命题组精心研制、具有良好导向作用的一道试题，也是近几年中考试卷中不可多见的亮点试题．

简介：Theeffectandmechanismofcarmustine(BCNU)combinedwithall-transretinoicacid(ATRA)ontheapoptosisofhumanglioblastomaU251cellswereinvestigatedbymeansof3-(4,5-dimethylthiazol-2-yl)-2,5-diphe-nyltetrazoliumbromide(MTT)assay,flowcytometry,reversetranscription-polymerasechainreaction(RT-PCR)andWesternblotanalysis.TheresultsshowthatBCNUorATRAshowstime-anddose-dependentinhibitioneffectsonhumanglioblastomaU251cellsandthecombinationofBCNUwithATRAshowsansynergisticinhibitioneffectonhumanglioblastomaU251cells,andthecombinedBCNUandATRAcansignificantlyinhibittheproliferationofhumanglioblastomaU251cells,andinducetheapoptosisofthem,makingthecellsarrestinthestageofG1phase,thestageofSandG2phasesdecline,therateoftheapoptosisofhumanglioblastomaU251cellsincrease,thecorrespondingmRNAexpressionofcyclinEandcyclin-dependentkinase2(CDK2)downregulatedandthecorrespon-dingmRNAexpressionofp27kip1unregulated.Inaddition,thecombinedBCNUandATRAreducedtheproteinexpressionofnuclearfactorkappaB(NF-κB).Takentogether,theseresultssuggestthatthetreatmentofhumanglioblastomaU251cellswithacombinationapplicationofATRAandBCNUcanexertsynergisticeffect,thecourseofthiskindofcombinationchemotherapymaylikelybeassociatedwithmultiplemolecularmechanismsforapoptosis,furthermore,thecyclinEandp27kip1shouldbeconsideredasnoveltargetsforcontrollingthegrowthofglioblastomacells.

简介：体外循环后精确控制鱼精蛋白用量对抗肝素,是预防鱼精蛋白中毒性反应的关键环节.由于血液中存在高浓度的亲脂性钾离子（如血液中钾离子的浓度约为5mg/L,血细胞中钾离子的浓度高达150mg/L）,而传统的聚阳离子选择性电极膜相中含有阳离子位点,在这种情况下,钾离子很容易进入聚合物膜相而干扰鱼精蛋白阳离子的测定.为了克服血液中钾离子的干扰,开发了肝素活化的聚阴离子选择性电极技术,成功实现了鱼精蛋白聚阳离子的检测,高浓度的钾离子不干扰测定.在最佳条件下,该电极对鱼精蛋白聚阳离子的检出限可达0.1mg·L-1,线性范围为0.5-10mg·L-1.

简介：为了进一步研究HIV-1外膜蛋白的结构和功能，获得足够量的糖蛋白，对HIV-1的外膜蛋白Env进行了修饰，利用PCR技术克隆目的基因，把Env基因构建到毕赤酵母Pichiapastoris表达载体中，把pPICZαB-Env表达载体转化到酵母中，根据基因重组技术，使Env基因和酵母基因组重组，筛选阳性重组子．

简介：本文通过对蛋白质结构基因的统计分析,建立了一个较精确的蛋白质二级结构的预测方法.我们不仅给出了一套α-螺旋及β-片层的构象参数和构象势,同时也给出了一整套的结构断裂参数。本文建立的基因密码方法对α-螺旋和价片层预测的成功率分别为88.0%和86.9%。

简介：为了更好地研究牙龈卟啉菌(Prophyromonasgingivalis,Pg)表面蛋白(Surface-associatedproteins,SAP)的生物活性,实验用SAP体外刺激小鼠颅骨和人外周血单个核细胞,分别用自动生化分析仪和放免方法检测培养液中Ca2+和IL-6的含量.同时,采用ELISA和MTT法分别测定SAP免疫小鼠的抗体效价和诱导的脾细胞转化程度.结果显示:一方面SAP是体外诱导骨吸收和前炎性因子合成的介质;另一方面SAP免疫的小鼠产生了抗SAP特异性抗体和脾细胞特异增生反应.这说明具有生物活性的SAP诱导了实验小鼠产生体液免疫应答和细胞免疫应答.

简介：利用基因工程手段，构建了两个用于在丝状噬蓖体主要外壳蛋白表面展示外源多肽的载体，这类载体可以使编码外源多肽的ＤＮＡ片段定向克隆到外壳蛋白的Ｎ末端ＤＮＡ序列中或附近，被修饰的外壳蛋白将分布于野生型丝状噬菌体外壳蛋白单位中间。