简介：FortheMonge-Amp`ereequationdetD2u=1,theauthorsfindnewauxiliarycurvaturefunctionswhichattaintheirrespectivemaximaontheboundary.Moreover,theupperboundedestimatesfortheGausscurvatureandthemeancurvatureofthelevelsetsforthesolutiontothisequationareobtained.

简介：首先,研究了Erdos1合著网络的特征属性,一方面使用节点的度、介数、接近中心性来描述Erdos1合著网络节点重要性,另一方面使用特征向量中心性和本文提出的高阶度参数来描述Erdos1合著网络节点影响力;然后,分别用逼近理想解的排序(TOPSIS算法)算法和主成份分析(PCA)对节点重要性和影响力排序;最后,利用修改的网页排名(PageRank)算法讨论了网络科学原创性论文中最具影响力的论文。

简介：InthispaperweestablishsharpH¨olderestimatesofharmonicfunctionsonaclassofconnectedpostcriticallyfinite(p.c.f.)self-similarsets,andshowthatfunctionsinthedomainofLaplacianenjoythesameproperty.Somewell-knownexamples,suchastheSierpinskigasket,theunitinterval,thelevel3Sierpinskigasket,thehexagasket,the3-dimensionalSierpinskigasket,andtheVicseksetarealsoconsidered.

简介：Zr1-xTixCo(x=0,0.1,0.2,0.3)alloyswerepreparedbyarc-meltingmethodandtheeffectofTisubstitutiononhydrogenstoragepropertieswasstudiedsystematically.Hydrogendesorptionpressure-composition-temperature(PCT)measurementswerecarriedoutusingSievert’stypevolumetricapparatusforZrCo(at473K,573Kand673K)andZr1-xTixCoalloys(at673K),respectively.ProductsafterdehydrogenationwerecharacterizedbyX-raydiffraction(XRD).Inaddition,thekineticsofZr1-xTixCohydridewasinvestigatedat473Kand673K,respectively,underhydrogenpressureof5MPa.ResultsshowedthatTisubstitutionforZrdidnotchangethecrystalstructureofZrCophase.Withtheincreaseoftemperaturefrom473Kto673K,theextentofdisproportionationforZrCoalloyincreased.WithTicontentincreasingat673K,thedesorptionequilibriumpressureofZr1-xTixCo-H2systemselevatedandthedisproportionationreactionofZr1-xTixCoalloyswasinhibitedeffectively.TisubstitutiondecreasedthekineticsrateandtheeffectivehydrogenstoragecapacityofZr1-xTixCoalloysslightly.Generallyspeaking,itwasfoundthatZr0.8Ti0.2Coalloyhadbetteranti-disproportionationpropertywithlessdecreaseofeffectivehydrogenstoragecapacitywhichwasbeneficialtotritiumapplicationintheInternationalThermonuclearExperimentalReactor(ITER).

简介：Inthiswork,MoOxpromotedIr/SiO2catalystswerepreparedandusedfortheselectivehydrogenolysisoftetrahydrofurfurylalcohol(THFA)to1,5-pentanediolinacontinuousflowreactor.Theeffectsofdifferentnoblemetals(Ir,Pt,Pd,Ru,Rh),supportsandIrcontentswerescreened.Amongtheinvestigatedcatalysts,4wt%Ir-MoOx/SiO2withaMo/Iratomicratioof0.13exhibitedthebestcatalyticperformance.ThesynergybetweenIrparticlesandthepartiallyreducedisolatedMoOxspeciesattachedonthemisessentialfortheexcellentcatalyticperformanceofIr-MoOx/SiO2.ThecatalystexhibitedabetterhydrogenolysisefficiencyofTHFAwiththeselectivityof1,5-pentanediolof65%–74%ataconversionofTHFAof70%–75%whentheinitialTHFAconcentrationisrangingfrom20wt%and40wt%.AndhighersystempressurewasalsoinfavoroftheconversionofTHFA.Duringastabilitytest,theconversionofTHFAand1,5-pentanediolyieldoverIr-MoOx/SiO2decreasedwithreactiontime,whichcanbeexplainedbytheleachingofMospeciesduringthereaction.

简介：Underinvestigationinthispaperisa(3+1)-dimensionalvariable-coefficientKadomtsev–Petviashviliequation,whichdescribesthepropagationofsurfaceandinternalwaterwaves.ByvirtueofthebinaryBellpolynomials,symboliccomputationandauxiliaryindependentvariable,thebilinearforms,solitonsolutions,B¨acklundtransformationsandLaxpairareobtained.Variablecoefficientsoftheequationcanaffectthesolitonicstructure,whentheyarespeciallychosen,whilecurvedandlinearsolitonsareillustrated.Elasticcollisionsbetween/amongtwoandthreesolitonsarediscussed,throughwhichthesolitonskeeptheiroriginalshapesinvariantexceptforsomephaseshifts.

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简介：Inordertoimprovetheflexibilityofpoly(propylenecarbonate)(PPC),poly(1,2-propylenesuccinate)(PPSu)wasusedtoplasticizePPCinabatchmixer.TheeffectsofPPSuonthemiscibility,thermalstability,mechanicalandrheologicalpropertiesoftheblendswereinvestigated.PPCwaspartiallymisciblewithPPSu.ItwasdemonstratedthatPPSudecreasedtheglasstransitiontemperatureandmeltviscosityofPPC,asshownintheDSCandrheologicalcurves.WiththeincreaseinPPSucontent,thePPC/PPSublendsshoweddecreasedtensilestrength,however,theelongationatbreakwasincreasedto1100%forthe70/30PPC/PPSublend.TheintroductionofPPSuprovidedanefficientandnovelplasticizationmethodtoextendtheapplicationareaofPPC.

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简介：利用密度泛函理论（DFT）中的B3LYP方法,在6-311G（d）基组的水平上系统研究了CaSin（n=1-10）团簇的几何构型、稳定性与光谱（红外与拉曼）性质.研究结果表明,CaSin团簇构型是在CaSin-1构型上戴帽1个原子而形成的;当n≥4,CaSin团簇的最低能量结构均为立体构型;Ca原子的掺杂降低了体系的化学稳定性;CaSi3与CaSi5是幻数结构;在相同的观察频段内,CaSi3团簇的红外与拉曼活性在低频段均表现较好,而在高频段拉曼活性则表现较差,与之不同的是CaSi5团簇的红外与拉曼活性在整个频段内都表现的较好.

简介：利用拓扑度方法，本文在Z-P-S空间中研究了半闭1-集压缩算子的固有值与固有元问题，改进和推广了相关文献中的结果．

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简介：利用水热方法制备了一个新的过渡金属镉配合物[Cd（1，3-BDC）（L）（H2O）2]·H2O（1，3-H2BDC=间苯二甲酸，L=2-（3-吡啶基）-1H-苯并咪唑），并通过元素分析、红外光谱和X-射线单晶衍射方法确定了该配合物的晶体结构．结构分析表明该配合物属于单斜晶系，P21／c空间群，晶胞参数a=1．01641（6）nm，b=2．08842（12）nm，C=1．00l38（6）nm，β=106．3360（10）°，V=2．0398（2）nm3，Z=4，R1=0．0207，wR2=0．494．配合物中CdⅡ“离子与L配体的1个吡啶N原子、1，3-BDC的4个氧原子和2个配位水的O原子配位，形成七配位的扭曲十面体结构．配体1，3-BDC的桥连相邻的CdⅡ离子形成一维聚合物链，相邻链间通过氢键和π…π作用形成三维超分子网络，并对该配合物的热稳定性和荧光性质进行了研究．

简介：Thereisagrowingsupportforthelowlyingscalarmesonsf0(500),f0(980),a0(980),and(800)tobegenerateddynamicallyfromtheinteractionofpseudoscalarmesons,whilethecaseofthenextsetofscalarresonancesathigherenergies,f0(1370),f0(1710),K0(1430)ismoreaquestionofdebate.Soisthecaseofthetensorresonancesf2(1270),f′2(1525),K2(1430).AnewperspectiveonthesestateshasbeenofferedinRef.[1]wherethef0(1370)andf2(1270)resonancesareshowntobegeneratedfromtheinteractionprovidedbythelocalhiddengaugeLagrangiansimplementingunitarization.Itisshownthattheideaofthenatureofthesestatesasvectormeson-vectormesoncompositestateshasbeentestedinmanyreactions.Yet,thepermanentdiscussionoftheissuedemandsextrachecksforotherobservablesand,inthissense,theweakdecaysbringanewsourceofvaluableinformationthatshouldservetotestdifferentmodels.

简介：采用对称性破损态方法结合密度泛函理论,选用反铁磁双核配合物[Cu2（MMBPT）2Cl4（H2O）2.5]（MMBPT=3-甲基-4-对甲基苯基-5-（2-吡啶）-1,2,4-三唑）作为研究对象,通过与实验数据相比较,探讨了不同密度泛函方法与基组对计算铜配合物交换耦合常数的准确度.结果表明,4种混合密度泛函DFT（B3LYP,B3P86,B3PW91和PBE0）的计算结果都能和实验所观察到的值-31cm-1符号一致,但只有B3PW91方法得到的结果和实验结果吻合程度最好,同时采用方法B3PW91方法计算所得的交换耦合常数Jab对基组的依赖性较大.研究表明,2个Cu（Ⅱ）离子之间弱的反铁磁相互作用主要源于单占据分子轨道SOMOs小的能量劈裂.

简介：标题化合物C22H29N3O3以简单易得的试剂为原料,在乙醇溶剂中,微波辐射下经两步多组分反应合成得到.其结构通过单晶X射线衍射法确定,晶体属三斜晶系,空间群P-1,相对分子质量Mr=383.48,晶胞参数a=1.14770（12）nm,b=2.0657（2）nm,c=1.00780（12）nm,V=2.1841（4）nm3,Z=4,晶胞密度Dc=1.166mg/m3,吸收系数μ=0.078mm-1,单胞中电子的数目F（000）=824.晶体结构用直接法解出,经全矩阵最小二乘法对原子参数进行修正,最终的偏离因子为R1=0.0709,wR2=0.1405.在晶体结构中新形成的噌啉环为近似于共平面结构,而其中的哒嗪环则为船式构象.