纳米二氧化钛粒子分散性能的研究

以四氯化钛为原料，采用溶胶-凝胶法技术合成路线，获得了平均粒径为63nm的二氧化钛粉末。采用分散技术，不仅可以改善粒子的分散性能，而且对粒子的生长也起到一定的抑制作用。研究表明：(1)采用SDS作为分散剂时，其极性基团和非极性基团分别与水和纳米TiO2粒子相结合，从而阻隔了TiO2粒子的团聚，起到分散作用。(2)以稀土元素La作为分散剂，其独特的轨道结构，不仅扩大了能量吸收的范围，更重要的是它与TiO2形成的络合物，使其成为相对独立的小团体，而它本身很小的固溶度使其难于形成合金化组元，结果被释放出来，从而形成更小的纳米TiO2粒子，起到分散纳米TiO2粒子的作用，并同时抑制纳米TiO2粒子的生长。     

5-(2′-苯骈噻唑偶氮)-8-氨基喹啉的合成及应用——分光光度法测定钯的新试剂

本文报道了新试剂5-(2′-苯骈噻唑偶氮)-8-氨基喹啉(BTAQ)的合成。研究了在溴化十六烷基三甲铵(CTMAB)增溶下,在弱酸性介质中它与钯的显色反应。建立了分光光度法测定微量钯的高选择性新方法,用于钯催化剂中微量钯的测定,结果满意。     

In（Ⅲ）－和Y（Ⅲ）－1，2－PDTA配合物的动态核磁共振研究

研究了Ｉｎ（Ⅲ）和Ｙ（Ⅲ）－１，２－丙二胺四乙酸配合物￣１ＨＮＭＲ谱的温度依赖性，其结果显示出８个乙酸质子处于不同的磁环境中，分４组ＡＢ谱。ＡＢ谱交换现象由氮原子翻转引起，通过全线型分析求得了速率常数及相关热大学参数。对不对称的氮原子，其翻转速率不同，靠近ＣＨ＿３─基团的氮原子翻转速率要比远离ＣＨ＿３─的小．活化能与金属离子的离子势呈线性关系。     

Investigation of a liquid-liquid extraction system based on non-ionic surfactant-salt-H2O and mechanism of drug extraction

Based on the investigation of a non-ionic surfactant-salt-H₂O liquid-liquid extraction system, general rules concerning salt selection are concluded and the mechanism of phase separation is explained. The extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydrochloride (PCN) in such a system is studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, which means that quantitative extraction is realized, while that of PCN is 77%. This system produces distribution coefficients (K_D) of 12.3 and 2.6, respectively, for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet absorbance; and molecular fluorescence spectra change of the drugs in the system studied.     

The origin of enhanced photocatalytic decomposition of ATP on TiO2 powders as induced by surface modification with lanthanide ions: important roles of ATP adsorption to the modified surface

Surface modification of TiO₂ powders with lanthanide salts (EuCl₃ or YbCl₃) enhanced photocatalytic decomposition of ATP. In comparison with the unmodified catalyst, a 3-fold increase in the ATP decay rate was observed with TiO₂ powders as prepared in 5 mM EuCl₃ (or YbCl₃) solution. The reason was ascribed to enrichment of ATP to TiO₂ powder with the lanthanide ions. Evidence was obtained by adsorption experiments where ATP concentration was monitored after dispersing TiO₂ powders into the solution. The ATP molecules adsorbed faster to TiO₂ powder and strongly stabilized there in the presence of Yb³⁺ than otherwise.     

Preparation and evaluation of nickelmesogen for micropacked gas chromatography

The preparation and mesomorphic properties of a substituted bis(dithiolene)nickel complex derived from 4, 4'-dimethoxybenzil are reported. The phase transition temperatures were based on data obtained by polarized light microscopy and differential scanning calorimetry. The mesogenic phase existed over the temperature range from 77 to 175 degrees C. A novel micropacked column (1.5 or 3 m x 1 mm i.d.) prepared from the slurry of bis[1,2-bis(4-n-undecyloxyphenyl)ethane-1,2-dithiolene] nickel(II) (5%, w/w), coated on Chromosorb W was applied for the separation of dialkyl sulfides. The non-linearity (discontinuity) of Van't Hoff plots suggests that the liquid crystal property existed even in the coated phase. Factors affecting the retention and the sample selectivity on the prepared column were examined by using a flame photometric detector (FPD). The separation might be based on the mechanism of ligand exchange, shape selectivity and polarity interaction besides the vapor pressure. LOD for the determination of dialkyl sulfides was below 1 ng for most of the analytes.     

7-氮杂-3,6-二氧杂-二环[3.3.0]辛-2-酮类化合物合成的新方法

5-甲氧基-2-（5H）-呋喃酮与氮酸硅烷基酯通过1，3-偶极环加成反应可以为7-氮杂-4-甲氧基-3，6-二氧杂-二环[3.3.0]辛-2-酮类化合物提供新的合成途径。通过元素分析、IR、^1HNMR、^13CNMR、MS等波谱分析进行了结构表征。     

Re_2(edt)_4的电子结构和电子吸收光谱的从头算研究

用密度泛函理论中的B3LYP/CEP-4G方法对Re2（edt）4进行了结构优化和自然键轨道计算,并用单电子激发组态相互作用方法（CIS）计算了Re2（edt）4的分子轨道和激发态。结果表明Re-Re之间不存在明显的三重键,进而很好地解释了Re2（edt）4分子的电子吸收光谱。     

Al掺杂对尖晶石型LiMn2O4结构及循环性能的影响

用柠檬酸作为螯和物的载体,采用溶胶-凝胶法合成了A l3 掺杂的锂离子电池正极材料L iA lxMn2-xO4。XRD,SEM研究表明,于800℃煅烧可获得单一尖晶石结构的物相;随着A l3 掺入量的增加,L iA lxMn2-xO4的晶格常数变小,晶格更趋于完整,有利于抑制因锂的反复脱嵌而造成的结构破坏。x=0.05时,首次放电容量为103.8 mAh.g-1,25次循环后放电容量还有100.6 mAh.g-1,容量衰减仅为3.08%。     

Sonochemical Degradation of Polychlorinated Biphenyls in Aqueous Solution

Ultrasonic waves in a liquid induce the formation of cavitation bubbles. Submitted to an oscillating pressure field, cavities filled with vapor and dissolved gas pulsate, grow and implode violently when they reach a critical resonant size. According to the 慼ot spot?theory, extremely high temperature and pressure are produced during the collapse of cavitation bubbles1. Under these extreme conditions, the molecules vaporized in the bubbles as well as in the surrounding condensed layer could …