双核银络合物[Ag_2(dppm)_2(Py)_2(μ-Cl)]ClO_4的合成与结构

二-(二苯基膦)甲烷(dppm)是一种易与金属形成多核络合物的有机膦配体。我们用dppm作为配体合成了一系列银的多核络合物,并对其结构进行了研究。本文报导了其中一个双核化合物[Ag_2(dppm)_2(Py)_2(μ-Cl)]ClO_4的合成及晶体结构、分子结构的测定。     

尺寸排除色谱扩展因子的保留体积依赖性

尺寸排除色谱扩展函数的方差即尺寸排除色谱柱中单分散高分子峰的扩展因子,以窄分布聚苯乙烯标样用分子量分离和扩展效应同时标准的方法作了测量。简单的理论分析导出了一个方程以表示扩展因子的保留体积依赖性,其中包括四个具有明确物理意义并可实验测量的参数。该方程与实验数据符合得相当好,并解释了扩展因子极值出现的条件。     

石墨炉原子吸收光谱无标样分析法的研究：Ⅰ.消除基体干扰

实现石墨炉原子吸收光谱绝对分析必须消除基体干扰，本研究采用有机基体改进剂，管壁原子化、热解涂层石墨管，峰面积积分吸收信号，Ｄ２灯或Ｚｅｅｍａｎ效应扣除背景，有效地控制和消除了海水基体对Ａｓ，Ｃｄ，Ｃｏ，Ｃｒ，Ｃｕ，Ｍｎ，Ｎｉ，Ｐｂ和Ｖ等元素的干扰，实现了无干扰测定。     

Separation and purification of isoflavones from a crude soybean extract by high-speed counter-current chromatography

A set of isoflavones with a broad range of polarity including daidzin, glycitin, genistin, acetyldaidzin, glycitein, acetylgenistin and daidzein was separated from a crude soybean extract by high-speed counter-current chromatography using a two-step operation. Three solvent systems were used: chloroform-methanol-water (4:3:2, v/v); chloroform-methanol-n-butanol-water (4:3:0.5:2, v/v); and methyl tert.-butyl ether-tetrahydrofuran-0.5% aqueous trifluoroacetic acid (2:2:0.15:4, v/v). The first solvent system was used for separating less polar isoflavones and the second for more polar isoflavones by eluting the lower organic phase. Genistin and glycitin, which were only partially resolved in the chloroform system, were separated by the third solvent system. Each isolated component showed 98-99% purity as determined by high-performance liquid chromatography analysis. Their structures were identified by LC-MS.     

Rh/Al2O3上CO和NO的吸附性能及相互作用

利用ＴＰ－ＩＲ动态方法研究了ＣＯ和ＮＯ在Ｒｈ／Ａｌ２Ｏ３上吸附性能和相互作用的动态行为，结果表明，Ｒｈ／Ａｌ２Ｏ３的孪生中心对ＣＯ的吸附强于对ＮＯ的吸会，线式和桥式中心则对ＮＯ的吸附强于对ＣＯ的吸附，ＣＯ和ＮＯ共吸附－ＴＰ（ＣＯ和ＮＯ中）－ＩＲ动态过程结果揭示出２２２４ｃｍ＾－１谱带的出现和强度的增加与孪生ＣＯ谱带以及吸附的ＮＯ谱带的强度减弱同时发生，表明是由吸附的ＮＯ和孪生ＣＯ形成Ｒｈ－ＮＣＯ。     

应用扩展的重叠分辨率法优化液相色谱条件分离二茂铁类化合物

本文对优化液相色谱分离条件的重叠分辨率法进行了改进与扩展：首先利用全范围的二元线性梯度淋洗进行溶剂强度的优化，再通过重叠分辨率法进行了溶剂选择性的优化，并且建立了计算机系统，使此方法程序化。利用此方法建立了分离Ｎ－二茂铁甲酰基－Ｎ＇－芳基硫脲类衍生物的最佳流动相体系。     

Preparation,characterization of crystalline zirconium phosphates and study on their acid stability and ion exchange behavior with uranyl ions

Two kinds of crystalline zirconium phosphate, - and -ZrP were prepared by direct method, and characterized by means of X-ray powder diffractometry, thermogravimetric analysis and pH titration. The total exchange capacity of -ZrP and -ZrP for Na⁺ ions determined by pH titration was 8.80 mmol/(g Zr(HPO₄)₂·6H₂O) and 3.80 mmol/(g NH₄ZrH(PO₄)₂·H₂O), respectively. The thermodynamic equilibrium constant of exchange reactions on -ZrP and on -ZrP at 25.0°C is 2.5 and 1.1, respectively. Although UO ₂ ²⁺ in solution is more preferred by -ZrP than by -ZrP, the selectivity of -ZrP for UO ₂ ²⁺ decreases with decreasing pH value while less effect of pH on the amount of UO ₂ ²⁺ ions exchanged to -ZrP has been found. It is also interesting to find out that both H⁺ and NH ₄ ⁺ ions in -ZrP can be replaced by UO ₂ ²⁺ ions existed in concentrated solution.     

EFFECT OF La_2O_3 AND CeO_2 ON CH_4-CO_2 REFORMING NICKEL CATALYST

IntroductionConsiderableattelltionisno\vbeillgpaidtotheCO7refonningof.etha..llto]forseveralreasonst(l)withthedevelopmentofindustrics.moreandnlorcCOZIsabettedintotheatmosphere,leadingto"greenhouseeffect",whichhasbroughtaboutgreatilltcreslallovertheworld.Th…     

磺酸型聚氨酯离聚物的离子导电性能

本文以多种聚醚为软段，二异氰酸酯（ＭＤＩ和ＴＤＩ）为硬段，合成了多嵌段聚醚聚氨酯，以此聚氨酯为基材，与ＮａＨ及１，３－丙碳酸内酯反应，进一步合成了一系列不同离子化程度的阴离子型碳化聚氨酯离聚物，用交流阻抗谱仪测定了样品的阻抗谱，由此计算出样品的离子电导率。研究结果表明其他条件相同时，以聚乙二醇（ＰＥＧ）为软段的样品具有较高的离子电导率；以聚环氧丙烷（ＰＰＯ）为软段的样品次之，以聚四氢呋喃（ＰＴＭＯ）为软段的样品最低，对于离子化程度不同的聚氨酯离聚物以金属离子和烷氧单元之比为０．０５时导电性能最好。阳离子为Ｌｉ＋和Ｎａ＋的样品具有相近的离子电导率。     

CeO2—LnO1.5固溶体的表征及其甲烷催化燃烧性能

向CeO2中引入Ln3 离子后形成的CeO2－LnO1.5（Ln=La，Nd，Sm，Gd）固溶体（n（Ce）：n（Ln）=1：1）是一种无贵金属的新型高效甲烷燃烧催化剂．比表面、XRD、Raman、TEM等分析证实，这类固溶体具有部分畸变的萤石结构，Ln3 进入晶格后诱发的结构变化使得团溶体的表面和本体能同时参与氧化还原反应．实验表明，该固态溶液体系是甲烷催化燃烧的良好催化剂．