电感耦合等离子体发射光谱法测定东北大豆中微量元素

用电感耦合等离子体原子发射光谱法 (ICP AES)测定了 11种东北大豆中大量、小量和微量元素。比较了两种湿法消解方法 ,HNO3 HClO4,HNO3 H2 SO4和干灰化法对分析结果的影响。由于大豆含有较多的油脂 ,用混合酸消解时费时较长且需加入较多的酸 ,从而可能产生较高的背景空白 ,因此对大豆样品的前处理采用干灰法较为合适。大豆中钾和磷是大量元素 ,本工作还研究了钾和磷对其他元素测定的影响。结果表明 ,大豆中钾和磷对其他微量元素的测定没有影响。结果还表明 ,这 11种大豆中的各微量元素的含量没有显著性差异

Separation of promethazine and thioridazine using capillary electrophoresis with end-column amperometric detection

Promethazine and thioridazine were separated and detected by capillary electrophoresis with end-column amperometric detection. The influence of pH Value on oxidation potential, the peak current and the resolution were studied and the following conditions was selected: 0.03 M Na2HPO4 and 0.015 M citric acid at pH 3.0, detection potential at 1.10 V. The detection limits of these two substances were in the range of 10(-8) mol/l. The linear range spanned two to three orders of magnitude. This method was applied to the detection of promethazine and thioridazine spiked in urine. (C) 1999 Elsevier Science B.V. All rights reserved.

Biochemical characterization of selenium-containing catalytic antibody as a cytosolic glutathione peroxidase mimic

A selenium-containing catalytic antibody (Se-4A4), prepared by converting reactive serine residues of a monoclonal antibody (4A4) raised against a GSH derivative into selenocysteines, acts as a mimic of cytosolic glutathione peroxidase (cGPX). To clarify the mechanism of action of this catalytic antibody, detailed studies on kinetic behaviour and biological activity were carried out. A rate of acceleration (k(cat)/K-m/k(uncat)) 10(7)-fold that of the uncatalytic reaction is observed. Under similar conditions, the turnover number (k(cat)) of Se-4A4 is 42% of that of the natural rabbit liver cGPX. The Se-4A4 reaction involves a Ping Pong mechanism, which is the same as that of the natural cGPX. The selenocysteine residue is located in the binding site of the antibody and is shown to be crucial for this activity. Of the thiol compounds tested, only GSH is able to serve as substrate for Se-4A4. It was demonstrated, using the free-radical-damage system (hypoxanthine/xanthine oxidase) of cardiac mitochondria, that Se-4A4 can protect mitochondria from free-radical damage at least 10(4)-fold more effectively than the natural cGPX.

2,5-双(4-羟基苯亚甲基)环戊酮中双电荷离子存在的串联质谱证据

应用串联质谱的碰撞诱导解离和联动扫描技术，研究了2,5-双(4-羟基苯亚甲基)环戊酮的质谱解离特征，提供了双电荷离子存在的实验证据。进一步对双电荷离子(m/z146)的碰撞诱导解离碎裂进行了讨论。

HIPS用镍系顺丁橡胶的工业技术开发

采用镍催化体系，以抽余油为溶剂，研究了丁二烯溶液聚合的聚合条件。结果表明，在ＢＲ－９０００生产装置上通过增加镍催化体系用量，降低水用量和适当提高聚合温度，可以制备出ＨＩＰＳ生产所需要的顺丁橡胶。

Bright blue electroluminescent devices utilizing poly (N-vinylcarbazole) doped with fluorescent dye

Bright blue electroluminescent devices have been fabricated using poly (N-vinylcarbazole) (PVK) doped with perylene as the emissive layer, poly(p-phenylenevinylene) (PPV) as the hole-transporting layer, 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), tris(8-hydroxyquinoline)aluminum (Alq(3)) as the electron-transporting layer, and Al as the cathode. A luminance of 700 cd/m(2) and a luminescent efficiency of 0.8% are achieved at a drive voltage of 36 V. In the experiment, it is found that the introduction of electron-transporting layer PBD has a great effect on the emissive color of the electroluminescent devices prepared by PVK doped with perylene. Yellow-green emission is observed from the device structure of glass substrate/indium-tin-oxide/PVK:perylene/Al. The possible emissive mechanisms are given. The effect of the transporting layer on the electroluminescence is also discussed. (C) 1997 Elsevier Science S.A.

双镥金属富勒烯的合成、提取与表征

自La@C_(82)被发现以来,能导致新分子、新材料不断涌现的金属富勒烯的研究就一直是富勒烯化学领域中最吸引人的分支,但是它的发展比较缓慢,直到K-H方法被应用于宏观量地合成金属富勒烯,这种情况才有所改善.现在,大多数镧系元素,包括La,Ce,Nd,Sm,Eu,Gd,Tb,Dy,Ho和Er,已通过金属/碳棒在低压氦气条件下的电弧放电过程被成功地包裹于富勒烯碳笼当中并被溶剂提取出来,它们提取液的质谱图均给出明显的M@C_(82)信号.与此相反,我们这里报道了一种特殊的镧系元素——镥,在它的金属富勒烯提取液中,只有双镥富勒烯,Lu_2@C_(2n),能被激光解吸电离飞行时间质谱与解吸电子轰击质谱观察到.含富勒烯与双镥富勒烯的碳炱用电弧放电法制备.简单来说,直径6mm的光谱纯碳棒,钻孔,填入99.99%Lu_2O_3与碳粉的混合物,使总原子比为1.0Lu/100C,此金属/碳的混合棒先在真空条件下(10~(-3)×133.332 Pa),2000 K处理3h,然后作为正极在160×133.332 Pa氦气中直流电弧放电,电弧电流80A.生成的碳炱用甲苯索氏提取后,再于高压釜中523 K时,

STUDIES ON THE SYNTHETIC, STRUCTURAL, ELECTRICAL, AND MAGNETIC-PROPERTIES OF THE NEW LAYERED OXIDES LN(2)MCO(2)O(7) (LN=SM, GD, M=SR, BA)

Three new oxides Ln(2)MCo(2)O(7) (Ln = Sm, Gd; M = Sr, Ba) have been synthesized in solid state reaction method. The powder X-ray diffraction spectra show that they are all isostructural with Sr3Ti2O7. The electrical resistivities in the temperature range 300-1100 K show that they are all semiconductors, and a transition to metals is observed at 1053, 1053, and 573 K for Sm2SrCo2O7, Gd2SrCo2O7, and Sm2BaCo2O7, respectively. The magnetic suspectivities of Gd2SrCo2O7 in the temperature range 300-673 K fit the Curie-Weiss law well. A plateau is observed in the curves of Sm(2)MCo(2)O(7) (M = Sr, Ba) which is attributed to the configuration state change of Co(III) from low spin to high spin. (C) 1995 Academic Press, Inc.

Study on comblike polymer electrolyte

New comblike polymers(CP) have been synthesized by reacting monomethyl ether of polyethylene glycol(PEGME) with poly(methyl vinyl ether-alt-maleic anhydride)(MA) and endcapping the residual carboxylic acid with methanol. Butanone was selected as a solvent for the esterification reaction in order to obtain a completely soluble product. They were characterized by IR, C-13 NMR and elemental analysis.

环化顺1，4－聚丁二烯浓溶液的流动行为

大多数线型高聚物浓溶液的流动行为呈现非牛顿性，线型顺１，４－聚丁二烯（ＬＢＲ）亦然，而环化顺１，４－聚丁烯（ＣＢＲ）的浓溶液在浓度达１７．８％时仍表现为牛顿流体。ＣＢＲ溶液的临界缠结浓度明显地高于ＬＢＲ，ＣＢＲ分子链间的缠结效应比ＬＢＲ弱得多，这是ＣＢＲ的分子链结构特征所致。

超氧自由基与嘧啶碱基及其核苷反应的ESR研究

用自旋捕集技术和ＥＳＲ方法，以ＭＮＰ为捕集剂，研究了紫外线辐照核黄素产生超氧自由基（Ｏ）等活性氧与嘧啶碱基及其核苷的反应。确定了尿嘧啶、胞嘧啶和胸腺嘧啶及其核苷所产生的自旋加合物自由基的类别，讨论了自由基的形成机制，揭示了超氧自由基与嘧啶碱基及其核苷的反应不是直接进行的，而是通过羟基自由基（ＯＨ）来实现的。

稀土催化四氢呋喃开环聚合

关于η~6-芳烃过渡金属有机络合物催化烯烃聚合的研究已早有报道.但对于η~6-芳烃稀土络合物催化烯烃聚合的研究至今未见报道.我们在研究了(η~6-C_6H_6)Nd-(AlCl_4)_3-AlR_3催化异成二烯聚合的基础上,又考察了不同芳烃烯土络合物和几种AlR_3组成的催化剂对丁二烯聚合的催化活性. 1.原料及试剂:丁二烯和烷基铝均为聚合级.汽油分别经浓硫酸,氢氧化钠水溶

α-Keggin结构钼硅酸钾杂多蓝的合成与结构

本文用控制阴极电位电解还原方法,制得了以Si为杂原子的Keggin结构二电子、四电子杂多蓝K_2H_4[SiMo_2~ⅤMo_(10)~ⅥO_(40)]·12H_20(Ⅰ)和K_3H_5[SiMo_4~ⅤMo_8~ⅥO_(40)]·12H_2O(Ⅱ).通过IR,UV,极谱,XPS,ESR及单晶X射线衍射对所合成的杂多蓝进行了表征,确定了被还原的Mo(V)位置位于不同的边共用三金属簇内,测定结果表明,Keggin结构杂多阴离子还原后,八面体结构有轻微畸变,畸变程度随还原程度增大而增大。

YBa_2Cu_3O_(7-Y)超导体激光熔凝处理的研究

利用CO_2激光对YBa_2Cu_3O_(7-Y)块材进行熔凝处理后,证明可逆反应式YBa_2Cu_3O_(7-Y)(?)Y_2Cu_2O_5+4BaCuO_2成立,在结构上消除了孔洞等缺陷,使晶粒细化均匀,有序化程度及致密度提高,有效地提高了材料的临界电流密度J_c,从而提出用CO_2激光制备高温超导体YBa_2Cu_3O_(7-y)超导体块材、带材及线材实用化的新工艺.