75 resultados para 338.17


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A series of 2,3,7,8,12,13,17,18-octakis(alkyl-thio)tetraazaporphyrins (H(2)OATTAP) with different alkyl chain lengths have been synthesized. Cyclic voltammetry and differential pulse voltammetry have been used to investigate the effect of the controlled lengths of the eight peripheral thioether tails on the redox behavior of the molecules. The electrochemical reduction of octakis(hexyl-thio)tetraazaporphyrins, MOHTTAP (where M = Cu, Ni), was studied in 1,2-dichloroethane at a platinum electrode. The Cu derivative was oxidized in one single-electron-transfer step to yield a pi-cation radical and reduced in three single-electron-transfer steps to yield a pi-anion radical, dianion and trianion, respectively. For the Ni derivative, electron transfer reactions involving both the central metal atom and the macrocyclic ring were observed. Electron transfer pathways are proposed based upon voltammetric and in situ spectroelectrochemical results.

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A new kind of conductive vanadium-17-molybdodiphosphate/graphite/methylsilicate composite was firstly prepared by the sol-gel technique and used as electrode material for the fabrication of amperometric hydrogen peroxide sensor. The remarkable advantage of the sensor is its excellent reproducibility of surface renewal by simple mechanical polishing.

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在BaMAl10O17 体系中 ,将M扩大到除镁以外的其它离子 ,研究和讨论了离子半径与基质结构的形成关系 ,提出能稳定(形成)尖晶石结构的M离子有相应的磁铅矿或β Al2O3 结构的化合物存在的思想 ,并研究了Eu2 +在体系中的发光性能。结果表明 ,M=Zn,Cd,Mn,Co,Li时可形成 β Al2O3 结构化合物 ,M=Ca,Be时不能形成这类结构 ,Ca形成多相共存 ,Be形成一未知相 ;Eu2 +在M=Li,Be,Zn体系中具有良好的发光性能 ,发射波长450nm ,半高宽在50nm附近 ,将是一类很有前途的新的蓝色发光材料 ,Eu2 +在M=Mn的体系中存在Eu2 +和Mn2 +的同时发射 ,在M=Cd体系中 ,Eu2 +产生一双重宽带发射。对实验结果进行了合理的解释

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The characterization of free base porphyrin 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H(2)OHTTAP) and its zinc(II) complexes [Zn(II)OHTTAP] containing eight thioether groups at the beta -pyrrole positions of the macrocycle was reported. Results obtained by cyclic voltammetry and differential pulse voltammetry indicated a five-electron reduction in five steps for each complex. They were oxidized in two single-electron-transfer steps to yield pi -cation radicals and dications and reduced in three single-electron-transfer steps to yield pi -anion radicals, dianions and trianions, respectively. The redox property of H(2)OHTTAP was unusual as compared to porphyrins (PPs) and phthalocyanines (Pcs). Each process was monitored by in situ thin-layer spectroelectrochemistry, which indicated that only the Ligand was electroactive. The existence of the eight hexylthio groups was responsible for the intrastack interactions and enhanced intracolumnar and intercolumnar electron motions, resulting in improved conductivity. Copyright (C) 2001 John Wiley & Sons, Ltd.

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本文提出表面扩散法的思想并应用于稀土三基色发光材料中蓝色组份BaMgAl10O17:Eu2+的制备.结果表明,同直接高温因相法制得的荧光体相比,利用表面扩散法制备的蓝色荧光体BuMgAl10O17:Eu2+,在相同的发光亮度条件下,激活剂Eu2+的浓度可以大为降低,从而为降低这类材料的成本提出了依据和可能.

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A series of new catalysts, K-14[Ln(As2W17O61)(2)]. xH(2)O (Ln = La, Pr, Sm, Eu, Gd, Tb, Dy, Tm and Yb) which can electrocatalyze reduction of nitrite are presented and their electrochemical behavior is described in this paper. Bis(2:17-arsenotungstate) lanthanates which are monovacant Dawson derivatives, exhibit two 2-electron and one 1-electron waves, attributed to electron addition and removal from the tungsten-oxide framework that comprises each anion structure. The formal potentials of redox couples are dependent on solution pH. Double-hump principle of formal potentials takes effect with increasing atomic number of lanthanide elements following their special electronic shell structure. The third waves of all the heteropolyanions have good electrocatalytic activities for nitrite reduction at pH 5.0.

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研究了助熔剂对BaMgAl_(10)O_(17)基质中Eu~(2+)发光的影响,结果表明,F~-离子的存在使Eu~(2+)形成了新的发光中心,在两个发光中心之间产生有效的能量传递.新的发光中心的形成使Eu~(2+)的猝灭浓度提高.

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Eight heteropoly blues of bis-2:17 molybdophosphate complexes with Lathanide, i.e., K17H2[Ln(P2Mo17O61)2] . nH2O and K17H4[Ln(P2Mo17O61)2] . nH2O were synthesized and characterized by elemental analyses potentiometric titration, IR, UV, polarography, cyclic voltammetry, X-ray photoelectron spectra X-ray powder diffraction, thermal analyses and ESR. Experimental results show that the properties of these series of heteropoly blues are different from those of their oxidized form, but no great changes in their structures were observed. The ligand P2Mo17O6110- remains alpha2-isomer's configuration.

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首次合成和离析了八种以缺位型Dawson结构钼磷杂多阴离子为配体的稀土杂多蓝K_(17)H_2[Ln-(P_2Mo_(17)O_(61))_2]·nH_2O和K_(17)H_4[Ln(P_2Mo_(17)O_(61))_2]·nH_2O(Ln=La,Pr,Sm,Yb).通过元素分析、电位滴定、红外光谱、紫外光谱、极谱、循环伏安、X射线光电子能谱、热重-差热分析和电子顺磁共振对杂多蓝进行了表征.实验结果表明,杂多阴离子还原为杂多蓝后,性质发生了某些变化,但结构基本不变,配体P_2Mo_(17)O_(61)~(10-)仍为a_2型.

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本研究利用AFLP和微卫星标记,以海湾扇贝杂交F1为作图群体,构建了海湾扇贝的遗传连锁图谱,并对壳色决定基因和与生长性状相关的QTL进行了定位。 共用55对AFLP引物组合对亲本和88个子代个体进行扩增,共得到了2424个位点,多态性位点为392个,占所有标记的16.17%。其中,母本标记121个,父本标记196个,共有标记75个。经卡方检验,共有331个标记(84.4%)符合孟德尔分离比,61个标记(15.6%)出现偏分离现象。偏分离标记中,36个(59%)为纯合子缺失。从35对微卫星引物中筛选出了10对多态性引物,得到了5个母本标记和6个父本标记。另外,将表现为质量性状的壳色标记作为形态标记一同进行连锁图谱构建。 分别利用母本和父本标记构建了海湾扇贝雌性和雄性连锁图谱。其中,共有包括109个AFLP标记、5个微卫星标记和1个壳色标记组成了雌性图谱的框架图,分布于16个连锁群。图谱总长度为338.8cM,平均间隔为5.29cM,图谱覆盖率为65.82%。雄性连锁图谱框架图共定位了186个标记,包括181个AFLP标记、5个微卫星标记,壳色标记未实现定位。图谱包括17个连锁群,总长度为780.3cM,平均间隔为6.56cM,图谱覆盖率为78.11%。通过SSR12位点的定位结果,可以将雌性图谱第7连锁群与雄性图谱17连锁群对应起来。 壳色标记定位在了雌性图谱第九连锁群上,说明橙色基因位点为杂合。我们将壳色基因命名为Orange1,两个标记——F1f335和D8f420与这一基因之间图距为0。在家系和群体中初步验证,这两个标记与壳色基因紧密或完全连锁。 共定位了16个与生长相关的QTL,它们分布于雌性图谱的2、3、5连锁群和雄性图谱的4、5、6、7、8连锁群上。每个QTL均发现了与其图距非常接近的分子标记(0.01-2.51%)。其中壳长、壳高、壳宽三个长度指标QTL成簇分布或部分重叠,可一同作为选择性指标,壳重和全湿重QTL位点也比较相近。只有软体部重位点单独分布,可能具有相对独立的遗传基础。

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高原314是中国科学院西北高原生物研究所农业中心通过有性杂交培育的春小麦新品种,2001年12月通过青海省农作物品种审定委员会审定,品种原代号为95-314,现定名为高原314,属小麦Var. graecum Korn的变种。品种组合为:高原602 * {[ST142 * [(82宁182 * 82原11) * 47-2]] * [(78-17-3 * 83-228-3) * (Chanal * 338)]}F_3。