等离子体原子发射光谱法研究纳米Al2O3材料对稀土离子(La3+、Eu3+和Yb3+)的吸附行为

采用等离子体原子发射光谱法(ICP-AES)为检测手段,以纳米Al2O3为吸附材料,系统地研究了其在静态条件下对稀土离子(La3+、Eu3+和Yb3+)的吸附性能,确定了最佳吸附及解脱条件.实验结果表明,在pH=8.0～9.0范围内,分析物可被定量吸附,用1.0 mol·L-1盐酸溶液可将吸附的稀土离子完全解脱.本方法对La3+、Eu3+和Yb3+的检出限分别为10.2 ng·mL-1、5.2 ng·mL-1和1.7 ng·mL-1,相对标准偏差(RSD)分别为3.9%、4.2%和2.9%(n=11,c=0.5μg·mL-1).所得实验数据显示,该吸附材料的吸附容量比色谱用氧化铝高2～3倍.     

中成药中痕量元素硒的分析方法

研究了原子荧光光谱法测定中成药中痕量元素硒的分析方法。在选定的最佳工作条件下 ,用HNO3 H2 O2 消解试样 ,加入盐酸使Se (Ⅵ )还原为Se (Ⅳ ) ,酒石酸消除共存离子的干扰。方法的回收率 95 7%～ 97 3 % ,检出限为 0 3 2ng·mL- 1,且测定样品快速、简便     

L-苏糖酸铜的制备及其标准生成焓

L 苏糖酸作为金属离子的载体,可使金属离子易与氨基酸或蛋白质结合而被动物吸收和利用[1]。本文以L 苏糖酸与Cu2(OH)2CO3·xH2O反应后的溶液浓缩加无水甲醇制得水合物Cu(C4H6O5)·0 5H2O(经HPLC分析,纯度>99 9%),用化学分析、元素分析、IR光谱、TD DTG和量热法进行了表征。1　实验部分1 1　试剂与仪器L 抗坏血酸(Vc)、B.R.(东北制药总厂);H2O2、CaCO3、H2C2O4和Cu2(OH)2CO3·xH2O均为A.R.(西安化学试剂厂);2400型元素分析仪(PE公司);Cu2+含量用Na2S2O3滴定法测定;TG 7型热重分析仪(PE公司);BRUKEREQUINOX 5…     

Syntheses and Crystal Structures of Copper（Ⅱ） and Nickel Complexes with 1,2,3-Triazole-carboxylic Acid

Three novel complexes [Cu(L1)2(H2O)2] (1), [Ni(L1)2(H2O)2]·(H2O)4(2,HL1=5-methyl-1-(4-methylphenyl)-1,2,3-triazole-4-carboxylic acid) and [Ni2 (HL2)2(CH3OH)6]·(CH3OH)2(3,H3L2=1,2,3-triazole-4,5-dicarboxylic acid) were synthesized and characterized by elemental analysis, IR and X-ray diffraction. Complexes 1 and 2 are mononuclear structures, and are assembled into a two-dimensional sheet by C(7) H(7)···O(3) weak interactions or hydrogen-bonding interaction. Complex 3 is a centrosymmetric dinuclear structure, and is assembled into a three-dimensional supramolecular structure by hydrogen-bonding interaction.     

辣根过氧化物酶催化过氧化氢氧化隐性亮绿显色反应的研究

以隐性亮绿 (RBG)为氢供体底物 ,研究了辣根过氧化物酶 -H2 O2 -RBG显色反应体系的酶催化特性。在 p H 5.0～ 6.0的条件下反应形成的酶催化产物亮绿 (BG)于 63 0 .6nm处有最大吸收 ,该显色反应测定 H2 O2 的表观摩尔吸光系数为 5.64×1 0 4 L·mol- 1·cm- 1,线性范围为 3 .55× 1 0 - 8～ 6.0× 1 0 - 6 mol/ L,检出限为 3 .55×1 0 - 8mol/ L。方法用于雨水中痕量 H2 O2 的测定 ,结果满意     

激光促进甲醇在杂多化合物上的表面反应

利用红外光谱 (IR)、程序升温脱附 (TPD)和激光促进表面反应 (L SSR)技术 ,研究了甲醇吸附于杂多化合物 H3PMo1 2 O40 · x H2 O、H3PW1 2 O40 · x H2 O、H6 PMo6 W6 O40 · x H2 O表面上所形成体系的振动结构、化学吸附形态和光促表面反应规律 .实验结果表明 ,在各固体材料表面上甲醇同时发生分子吸附和解离吸附 ,且在室温条件下体系即发生显著的光促表面反应 ;与甲醇吸附强度和吸附量相比 ,反应体系的振动结构对 L SSR效率起着更重要的作用 .根据表征和反应结果 ,分析了体系中活性物种的产生途径 ,并给出了反应机理的模型     

L-苏糖酸氧钒的制备及其表征

L 苏糖酸作为金属离子的载体,可使金属离子易于与氨基酸或蛋白质结合而被动物吸收和利用[1-3],钒在1971年被确定为生物体必需的微量元素[4],具有多种生理作用和药理活性,与糖尿病的关系十分密切。近年来国内外用于抗糖尿病生物学研究的钒化合物绝大多数为简单的盐类化合物,脂溶性小,难以吸收,同时对胃肠道刺激性大[5]。本文以L 苏糖酸钙与草酸氧钒(VOC2O4)反应后的溶液加无水乙醇制得[VO(C4H6O5)]2·3H2O,并进行等离子发射光谱(ICP)、元素分析、IR光谱、TG DTG表征。1　实验部分1.1　试剂与仪器L 抗坏血酸(Vc),H2C2O4·2H2O…     

盐卤硼酸盐化学(非汉字字符)——MgO·nB_2O_3-18%MgCl_2-H_2O过饱和溶液20℃结晶动力学

用结晶动力学方法对不同摩尔比的 Mg O/B2 O3在摩尔分数为 1 8% Mg Cl2 -H2 O中的过饱和溶液在2 0℃的结晶动力学过程进行了研究 .n(Mg O) /n(B2 O3) =1 /1和 1 /1 .5时分别结晶析出 2 Mg O· 2 B2 O3·Mg Cl2 · 1 4H2 O和 2 Mg O· 3 B2 O3· 1 5 H2 O(多水硼镁石 ) .n(Mg O) /n(B2 O3) =1 /2时依次结晶析出 Mg O·3 B2 O3· 7.5 H2 O,Mg O· 2 B2 O3· 9H2 O和 2 Mg O· 3 B2 O3· 1 5 H2 O(多水硼镁石 ) 3种固相 .n(Mg O) /n(B2 O3)=1 /3时结晶析出不同结晶水的六硼酸镁 Mg O· 3 B2 O3· 7H2 O和 Mg O· 3 B2 O3· 7.5 H2 O.析出固相采用X射线粉末衍射、红外光谱和热分析进行物相鉴定 .拟合并给出结晶动力学方程 ,同时对水合镁硼酸盐的结晶反应机理进行了探讨     

L-α-氨基酸铜(Ⅱ)-联吡啶混配配合物的合成及表征

合成了 4种氨基酸 铜 (Ⅱ ) 2 ,2′ 联二吡啶 (Bpy)的混配配合物 ,用元素分析、摩尔电导率、IR和UV -Vis对配合物进行了表征和结构推测。 4种混配配合物的组成分别为 :[Cu(Bpy) (L thre) ]·ClO4·H2 O ,[Cu(Bpy) (L ile) ]·ClO4·0 .5H2 O ,[Cu(Bpy) (L meth) ]·ClO4·0 .5H2 O ,[Cu(Bpy) (L ly) ]·ClO4·H2 O(L thre为苏氨酸 ,L ile为异亮氨酸 ,L meth为蛋氨酸 ,L ly为赖氨酸 )。Bpy和L 氨基酸皆作为双齿配体与中心铜离子发生配位。     

氯化钆与L-酪氨酸和甘氨酸三元固态配合物的热化学及热分解动力学研究

合成表征了氯化钆与L 酪氨酸和甘氨酸形成的三元固态配合物Gd(Tyr) (Gly) 3 Cl3 ·3H2 O .用具有恒温环境的溶解 -反应热量计 ,测定了配位反应GdCl3 ·6H2 O (s) +Tyr (s) +3Gly (s) =Gd(Tyr) (Gly) 3 Cl3 ·3H2 O (s) +3H2 O (l)在 2 98.15K时的反应焓为 ( 9.45 1± 0 .468)kJ·mol-1 .计算得配合物Gd(Tyr) (Gly) 3 Cl3 ·3H2 O (s)在 2 98.15K时的标准摩尔生成焓为ΔfH m =-( 4 2 69.7± 2 .3 )kJ·mol-1 .并用热分析手段对配合物进行了非等温热分解动力学研究 ,推断配合物第二步热分解反应机理为二级化学反应 ,其动力学方程为 :dα/dT =(A/β)exp( -E/RT) ( 1-α) 2 ,求得分解反应的表观活化能为E =2 15 .17kJ·mol-1 ,指前因子为 10 1 8.71 s-1 .     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Effect of the Method of Modification of Zeolite X on Selectivity of Catalytic Methylation of Toluene

Theoretical and Experimental Chemistry - The effect of the method of modification of catalysts based on zeolite X by cesium and magnesium cations (ion exchange and impregnation) on the selectivity...     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of tetrabenzoporphins of the basis of isoindoline

Chemistry of Heterocyclic Compounds -