用会聚偏振光测定双轴热拉伸有机玻璃板的双折射值的研究

介绍了用会聚偏振光测定双轴热拉伸定向有机玻璃板双折射值的原理和实验方法,并提出了对Kramer计算公式的简化和改进。测定了双折射值与拉伸度、拉伸温度的关系并分析了干涉图。     

聚电解质与相反电荷表面活性剂的相互作用

通过透光度测定、电导滴定和粘度法考察了阳离子聚电解质聚苯乙烯 4 乙烯基吡啶硫酸甲酯盐与阴离子表面活性剂十二烷基硫酸钠 (SDS)的相互作用。研究表明 ,在表面活性剂未过量时 ,二者之间的静电作用占主导地位 ,并且当二者电荷总量相等时 ,生成的复合物沉淀最多 ;在表面活性剂过量后 ,复合物可部分溶解 ,溶解的原因是疏水相互作用。本文初步阐述了二者的作用机理     

Study of the Complexation Behavior of Calixarene with Transition Metal Cations by UV—vis and Fluorescent Spectra

A new fluorescent compound based on calix[4] arene skeleton was synthesized.Its complexation ability with transition metal ions,such as Fe^3 ,Co^2 ,Ni^2 ,Cu^2 ,Zn^2 and Ag^ ,Was investigated by UV-vis and fluorescent spectra.     

Strong influences of cocatalyst on ethylene/propylene copolymerization with a MgCl2/SiO2/TiCl4/diester type Ziegler-Natta catalyst

Using triethylaluminum (TEA), triisobutylaluminum (TIBA) or TEA/TIBA mixtures of molar ratio 75/25, 50/50 and 25/75 as the cocatalyst, five different ethylene-propylene copolymer samples were synthesized by a MgCl₂/SiO₂/TiCl₄/diester type Ziegler-Natta catalyst in a slurry polymerization process. The synthesized copolymers are strongly heterogeneous in chain structure and were fractionated into part of nearly random copolymer and part of segmented copolymer. Both polymerization activity and copolymer structure were found to be markedly changed when the cocatalyst was changed from TEA to TEA/TIBA mixtures or pure TIBA. As the content of TEA in cocatalyst increases, yield of the random part of product increases and the yield of the crystalline segmented copolymer part decreases. There is also a decrease in ethylene content of the whole product with increasing TEA amount. Copolymerization behaviors of the TEA/TIBA mixture activated catalysis systems are not simple superposition of those activated by pure TEA and TIBA. When a 50/50 TEA/TIBA mixture was used as cocatalyst, the copolymerization activity became the highest, and yields of both the random copolymer part and the segmented copolymer part are close to the highest level. On the other hand, both parts of the copolymer produced with a 50/50 TEA/TIBA mixture are relatively more blocky than the products of TEA or TIBA systems, and difference in ethylene content between the random part and the segmented part was the smallest. The segmented copolymer part of three typical samples was further fractionated by temperature-gradient extraction fractionation into fractions of different ethylene content and sequence distribution. Changing TEA content in the cocatalyst exerted strong influences also on the fraction distribution of the segmented part of copolymer.     

Determination of inosine 5′-monophosphate and guanosine 5′-monophosphate in pig feed by capillary zone electrophoresis

A capillary zone clectrophoresis method was developed for the determination of IMP and GIMP, commonly used as flavor enhancers in poultry feed, in a real sample of complex composition. A baseline separation of inosine 5′-monophosphate and guanosine 5′-monophosphate was achieved within 10 min and the other components in the sample did not interfere with the separation. Quantitative results obtained from pig feed samples are presented. The separation conditions and experimental reproducibility are also discussed.     

Synthesis and Characterization of Novel Orange-emitting Iridium（Ⅲ） Complexes with Diphenylquinoline Ligands Containing Fluorinated Substituent

Three new cyclometalated iridium（m） complexes based on ligands of diphenylquinoline with fluorinated subsfituents were prepared, and characterized by elemental analysis （EA）, ^1H NMR, and mass spectroscopy （MS）. The photophysical and electrophosphorescent properties of the complexes were briefly discussed.     

铬（Ⅲ）邻菲咯啉,8—羟基喹啉配合物／Y型分子筛的制备及苯酚催化羟化

制备了铬（Ⅲ）邻菲咯啉，８－羟基喹啉配合物／Ｙ型分子筛，利用元素分析，ＳＥＭ，ＵＶ－ＶｉｓＢＥＴ及ＸＲＤ等方法确定了分子筛选笼中金属配合物的生在及其晶体结构，考察了实验参数对苯酚转化率及产物选择性的影响。     

碳酸氢铵沉淀法制备氧化钇粉体时反应条件对产物粒度的影响

研究了碳酸氢铵沉淀法的反应条件对氧化钇粒度的影响,探讨了粒度变化规律。发现在沉淀反应中,晶型碳酸钇铵的形成与否是影响氧化钇粒度的关键因素。在较低的反应温度下,当碳酸氢铵和氯化钇的浓度大于0.25mol·L-1,摩尔比大于5,陈化时间大于60min时得到碳酸钇铵沉淀,经煅烧可获得粒度(D50)大于1μm的氧化钇。当反应物浓度较低、摩尔比小,陈化时间较短时得到无定型碳酸钇沉淀,煅烧沉淀可获得粒度(D50)小于0.5μm的氧化钇。实验证明选择适当的沉淀反应条件,可制备D50在0.3～10μm范围内的不同粒度级别的氧化钇粉体。