乙苯氧化脱氢钨硅酸催化剂的研究

考察了钨硅酸及其盐对乙苯氧化脱氢制苯乙烯的催化行为。认为表面积碳物是活性中心,苯乙烯的收率随积碳物C/H增大而增加;载体的比表面积对活性有明显影响。还发现有苯甲酸生成,CO_2主要来自表面积碳物的氧化。     

Effect of Laser Cooling on Frequency Standard of Single Ca^＋ Ion Trapped in a Radio-Frequency Paul Trap

The source of systematic frequency shift of single-ion optical frequency standard of^40 Ca^＋ ion trapped in endcap trap and laser-cooled to a few of mK is analysed and calculated. Second-order Doppler shift, Stark shift due to micromotion and thermal motion, blackbody Stark shift and ac Stark shift are calculated for the ground state and excited 3d ^2D5/2 state. The Hertz-level measurement of the optical clock frequency in a single ^40Ca^＋ ion can be performed.     

A Novel Diterpenoid,11—O—β—D—glucopyranosylneo—triptophenolide, from Tripterygium wilfordii Hook.f

A new diterpenoid was isolated from the ethanolic extract of the dried root bark of Tripterygium wilfordii Hook.f. It is the first example of abietane diterpenoid glycoside isolated from Tripterygium wilfordii Hook.f.Its structure was identified to be 11-0-β-D-glucopyranosyl-neotriptophenolide based on spectral methods.     

Asymptotic Analysis of a Modified Lorenz System

We investigate the dynamical behaviour of a modified Lorenz system.Some basic dynamical properties,such as bifurcations,routes to chaos,periodic windows,and some Poincare mappings of this system are studied,either analytically or numerically.Also,the compound structure of the butterfly-shaped attractor is explored.     

二空缺Dawson型钨磷酸盐K_(10)Na_2H_2P_2W_(16)O_(60)·18H_2O的合成、结构和溶液的稳定性

用刚酸化的Na_2WO_4溶液(H~+/WO_4~(2-)=1.14,摩尔比)与Na_2HPO_4混合,酸化至pH6.5～6.9,再加入KCl固体,可制得K_(10)Na_2H_2P_2W_(16)O_(60)·18H_2O晶体。经元素分析、VO~(2+)光度滴定、~(31)PNMR、~(183)W NMR和紫外光谱等研究,确定为二空缺Dawson型结构;其溶液经60℃加热后,立即分解成H_7PW_8O_(33)~(6-);将K~+换成Na~+时,主要分解产物为PW_(11)O_(39)~(7-)。     

染料分子印迹聚硅氧烷的制备及性能研究（I）

分别以分散蓝和分散红两种染料为模板分子，3种硅烷偶联剂为功能单体，二氧化硅微球为载体，应用自组织法，制备了两种染料分子印迹的微球形聚硅氧烷。采用分光光度法，研究了分子印迹聚硅氧烷对各自模板分子的吸附性能及选择性识别性能。结果表明，与非印迹聚硅氧烷相比，染料分子印迹的聚硅氧烷对其模板分子具有较高的吸附能力，分子印迹聚硅氧烷的吸附速率也被讨论。     

酒石酸亚铁分光光度法测定茶多酚

采用没食子酸丙酯为基准物质酒石酸亚铁作为显色剂，光度法测定茶多酚制品中茶多酚的含量。最大吸收波长５４０ｎｍ摩尔吸光系数２．６５×１０＾３回收率为９８％－１０１％，相对标准偏差为０．９０％。方法简便，结果令人满意。     

轴对称场的电阻网格模拟

本文介绍利用电阻网格模拟轴对称场的原理和方法。并把模拟实验结果与数值计算结果对比，证明模拟实验的精确性比较好，克服了用电解槽法模拟所特有的误差。