Experimental study of the two-proton correlated emission from the excited states of Ne-17,Ne-18 and S-28,S-29

A series of experiments have been performed by complete kinematics measurements to study two-proton (2p) correlated emission from the excited states of Ne-17,Ne-18 and S-28,S-29 via the Coulomb excitation by bombarding on Au-197 target. 2p and residua coincident events were picked Out under strict conditions. Visible p-p correlations were observed. It is shown that 2p can be emitted from the high-lying excited states. 2p halo may lead to 2p emission with large spectroscopy factor for the states close to or beyond the threshold.

Gadolinium heteropoly complex K-17[Gd(P2W17O61)(2)] as a potential MRI contrast agent

Gadolinium heteropoly complex K-17[Gd(P2W17O61)(2)] has been evaluated by in vitro and in vivo experiments as a potential contrast agent for magnetic resonance imaging (MRI). The thermal analysis and conductivity study indicate that this complex has good thermal stability and wide pH stability range. The T-1 relaxivity is 7.59 mM(-1) s(-1) in aqueous solution and 7.97 mM(-1) s(-1) in 0.725 mmol l(-1) bovine serum albumin (BSA) solution at 25degreesC and 9.39 T, respectively. MR imaging of three male Sprague-Dawley rats showed remarkable enhancement in rat liver after intravenous injection, which persisted longer than with Gd-DTPA. The signal intensity increased by 57.1 +/- 16.9% during the whole imaging period at 0.082 mmol kg(-1) dose. Our preliminary in vitro and in vivo studies indicate that K-17[Gd(P2W17O61)(2)] is a potential liver-specific MRI contrast agent.

Ti_(0.17)Zr_(0.08)V_(0.34)Nb_(0.01)Cr_(0.1)Ni_(0.3)氢化物电极合金微观结构及电化学性能研究

采用XRD、FESEM-EDS、ICP及EIS等方法研究了Ti0.17Zr0.08V0.34Nb0.01Cr0.1Ni0.3氢化物电极合金微观结构和电化学性能。X射线衍射分析表明:该合金由体心立方结构(bcc)的V基固溶体主相和少量六方结构的C14型Laves相组成;FESEM及EDS分析表明:V基固溶体主相形成树枝晶,C14型Laves相呈网格状围绕着树枝晶的晶界,元素在两相中的分布呈现镜像关系。电化学性能测试结果表明:该合金的氢化物电极在303￣343K较宽的温度区间内,表现出较高的电化学容量,在303K和343K时,电化学容量分别为337.0mAh·g-1和327.9mAh·g-1。在303K循环100周后,容量为282.7mAh·g-1。ICP分析结果表明,氢化物电极在充放电循环过程中,V及Zr元素向KOH电解质中的溶出较为严重。EIS研究表明,金属氢化物电极表面电化学反应的电荷转移电阻(RT)随循环次数的增加而增加,相应的交换电流密度则随循环次数的增加而降低。氢化物电极循环过程中RT的增大以及V和Zr元素的溶解,可能是导致电极容量衰减的主要原因。

BaMgAl_(10)O_(17)∶R~(2+)(R=Eu,Mn)的真空紫外光谱特性

采用高温固相反应法合成了BaMgAl10 O17∶R(R =Eu ,Mn)荧光体 ,测量了荧光体的真空紫外激发光谱和相应的发射光谱 ,观察到基质吸收带位于 16 5nm附近 ,Mn2 + 离子的吸收位于 170～ 2 40nm范围 ,Eu2 + 离子的 4f→ 5d吸收位于 2 10～ 40 0nm范围。真空紫外光谱特性的研究表明基质与激活离子之间存在较好的能量传递。

Hydrothermal syntheses and crystal structures of bimetallic cluster complexes [{Cd(phen)(2)}(2)V4O12]center dot 5H(2)O and [Ni(phen)(3)](2)[V4O12]center dot 17.5H(2)O

The hydrothermal reactions of vanadium oxide starting materials with divalent transition metal cations in the presence of nitrogen donor chelating ligands yield the bimetallic cluster complexes with the formulae [{Cd(phen(2))(2)V4O12].5H(2)O (1) and [Ni(phen)(3)](2)[V4O12] . 17.5H(2)O (2). Crystal data: C48H52Cd2N8O22V4 (1), triclinic. P (1) over bar, a = 10.3366(10), b = 11.320(3), c = 13.268(3) Angstrom, alpha = 103.888(17)degrees, beta = 92.256(15)degrees, gamma = 107.444(14)degrees, Z = 1; C72H131N12Ni2O29.5V4 (2), triclinic. P (1) over bar, a = 12.305(3), b = 13.172(6), c = 15.133(4), alpha = 79.05(3)degrees, beta = 76.09(2)degrees, gamma = 74.66(3)degrees, Z = 1. Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.59degrees < theta < 26.02degrees and 2.01degrees < 0 < 25.01degrees using the omega-scan technique, respectively. The structure of 1 consists of a [V4O12](4-) cluster covalently attached to two {Cd(phen)(2)}(2+) fragments, in which the [V4O12](4-) cluster adopts a chair-like configuration. In the structure of 2, the [V4O12](4-) cluster is isolated. And the complex formed a layer structure via hydrogen bonds between the V4O12](4-) unit and crystallization water molecules.

Effect of alkyl group length on the conductivity in the 2,3,7,8,12,13,17,18-octakis(alkyl-thio)tetraazaporphyrins and redox properties of the metallooctakis(hexyl-thio)tetraazaporphyrins

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.

Polishable amperometric hydrogen peroxide sensor based on sol-gel-derived conductive composite containing vanadium-17-molybdodiphosphate

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.

BaMAl_(10)O_(17)(M=Be,Mg,Ca,Zn,Cd,Mn,Co,Li)体系的合成、结构和Eu~(2+)在其中的发光

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

Electrochemical and in situ spectroelectrochemical behavior of 2,3,7,8,12,13,17,18-octakis(hexyl-thio) tetraazaporphyrin (H(2)OHTTAP) and (Zn(II)OHTTAP)

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.

表面扩散法制备BaMgAl_(10)O_(17):Eu~(2+)荧光体

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.

ELECTROCHEMICAL-BEHAVIOR OF BIS(2 /17-ARSENOTUNGSTATE) LANTHANATES AND THEIR ELECTROCATALYTIC REDUCTION FOR NITRITE

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.

BaMgAl_（10）O_（17）∶Eu~（2＋）中Eu~（2＋）的发光中心

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.

SYNTHESIS AND CHARACTERIZATION OF HETEROPOLY BLUES OF BIS-2/17 MOLYBDOPHOSPHATE COMPLEXES WITH LANTHANIDE

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.

双2:17钼磷系列稀土杂多蓝的合成和性质研究

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.

刺参遗传连锁图谱构建及卵母细胞成熟过程研究

第一部分 刺参遗传连锁图谱的构建 利用AFLP和微卫星标记以一个远缘地理杂交家系为作图群体，以拟测交理论为作图策略，构建了刺参Apostichopus japonicus的雌性和雄性遗传连锁图谱。利用62对AFLP引物组合，对亲本和93个个体进行了分离分析，共得到3572个标记，其中具有多态性的标记为点数为1133个，多态性比例为31.5%。平均每个引物对产生18.3个多态片段。1133个多态性位点中，294个标记在父母本中都出现并在后代中分离，839个标记在父本或母本中出现并在子代分离，其中母本443(52.8%)个分离标记，父本396(47.2%)个分离标记。卡方检验显示，556个标记符合孟德尔1:1分离。筛选微卫星标记中30个在家系中具有作图信息，其中19个可用于母本作图，19个可用于父本作图。 利用Mapmaker 3.0/EXP软件对分离标记进行连锁分析。358个分子标记用于雌性遗传连锁分析，其中包括19个微卫星标记，199个AFLP标记和11个微卫星标记定位在雌性框架图谱中。雌性框架图谱共有25个连锁群，总长度为3148.3 cM。标记之间最大间隔为37.5 cM，平均间隔为17.0 cM，连锁群的分子标记数最大为21个最小为4个。用于雄性连锁分析的分子标记共有332个，其中包含19个微卫星标记。207个标记定位于23个连锁群上，其中AFLP标记数为196个，微卫星标记数为11个。23个连锁群总长度为3059.8 cM，标记间最大间隔38.6 cM，平均间隔16.6 cM。每个连锁群的长度范围在40 cM到271.4 cM之间，标记数在18到4个之间，包括二、三连体在内的雄性连锁图谱共覆盖3227 cM。雌雄基因组的预测长度分别为4053.7 cM和3816.3 cM，因此，所构建的雌雄连锁图谱覆盖率分别为84.0%和84.5%。通过共有微卫星标记，有3个连锁群在两个图谱中对应。分子标记在两个图谱中呈均匀分布，没有成簇现象。 分子标记筛选、遗传图谱的构建为刺参分子标记辅助选择育种，经济性状QTL定位和比较基因作图打下基础，并且最终将促进中国刺参遗传改良和新品种的培育工作。 第二部分 卵母细胞成熟过程研究 对刺参卵母细胞的体外诱导成熟方法进行探索，并且通过透射电子显微镜、扫描电子显微镜和激光共聚焦显微镜结合超薄切片技术及间接免疫荧光染色技术研究卵母细胞成熟的生物学过程。 分别利用在海参中有诱导作用的海星神经提取液和二硫苏糖醇(DTT)对从成熟卵巢解剖出的刺参卵母细胞进行诱导成熟试验，结果显示，刺参的卵母细胞在海水中不会发生自发成熟，海星神经提取液以及神经提取液加滤泡悬浮液对卵母细胞没有诱导成熟的作用，而二硫苏糖醇处理可以诱导卵母细胞生发泡破裂，当DTT溶液的浓度处于10-1 mol/L到10-3 mol/L之间时，对刺参卵母细胞的促熟作用较为明显，在10-2 mol/L左右时，卵母细胞的诱导成熟率可以达到90%以上。未成熟的卵母细胞处于第一次减数分裂前期，不具备受精能力。经DTT诱导后，生发泡发生移动并破裂，染色体排列到赤道板上，然后第一、二极体先后排出，诱导成熟的卵母细胞排出极体的时间与自然受精的卵子一致。在卵母细胞成熟过程中有受精膜举起的现象，说明精子入卵不是受精膜举起的必要条件。卵母细胞只有在生发泡破裂之后才具有受精能力，从生发泡破裂到第二极体排出前的整个减数分裂过程中，卵母细胞都可以受精，但是只有在第一极体排出前受精的卵母细胞才能发生卵裂。人工促熟的卵母细胞受精后，形成的胚胎似乎并不能正常发育，试验过程中最多只得到了8细胞期的胚胎，之后细胞便产生畸形并停止分裂，最终裂解消失。 利用DTT诱导刺参卵母细胞成熟，综合运用光镜、电子显微镜及激光共聚焦技术观察卵母细胞成熟过程，分析了卵母细胞表面动物极突起在卵母细胞脱滤泡中的作用，以及卵母细胞动物极突起和微管组织在生发泡移动过程中所起的作用。卵母细胞通过动物极突起连接到滤泡上，在脱滤泡作用开始时，卵母细胞动物极突起刺入并穿过滤泡膜，使得滤泡膜表面形成一个缺口，然后整个卵母细胞开始从缺口处挤出。脱滤泡的作用力来源有两种：胶膜层的水合作用以及滤泡的收缩。通过激光共聚焦显微镜观察，未成熟的卵母细胞中存在5种类型的微管，并且有两个微管组织中心锚定在卵母细胞突起下方。减数分裂重新启动时，生发泡沿微管向动物极移动，至细胞膜下时破裂。微管解聚对照实验证明驱动生发泡移动的细胞结构为微管束。生发泡破裂后，两个微管组织中心组织形成减数分裂纺锤体，然后第一极体以“收缩-排出”的独特方式排出。 本研究填补了刺参繁殖生物学研究中的缺失环节，为刺参人工繁育技术提供理论基础和指导。