乙酰丙酮在低温电热蒸发ICP-AES中的化学改进作用机理研究

近年来 ,低温蒸发技术的研究和应用引起了人们的重视 [1～ 3 ] .我们 [4]曾报道应用乙酰丙酮试剂作化学改进剂 ,于石墨管中低温 (～ 75 0℃ )蒸发铍的乙酰丙酮螯合物的 ETV-ICP-AES法 ,并用于人发中痕量铍的测定 .本文从机理上探讨了待测物 (铍或铬 )在石墨管中的蒸发及传输形式 ;研究了相应的乙酰丙酮螯合物的生成条件及主要影响因素 ;在此基础上得出在低温蒸发条件下相应的规律 .1　实验部分1.1　仪器装置　所用的 ICP-AES仪器、电热蒸发装置及它们之间的连接与文献 [1,4]相同 .紫外 -可见分光光度计 (日本岛津 UV-2 0 0 0 ) ,仪器…     

三聚氰胺聚磷酸盐阻燃剂的合成与表征

采用硅钨酸为催化剂,在甲醇反应介质中由三聚氰胺与聚磷酸反应制得三聚氰胺聚磷酸盐,用元素分析、IR、XRD、TG与DSC等对其进行了分析和表征,并对其阻燃性能进行了评价。从热分析可知,当温度升至684．8℃时,其热损失残余量为43．52％;在653．5℃时有1明显吸热峰,吸热量为629．5J/g涂覆含三聚氰胺磷酸盐的防火涂料的5层板在模拟实际火灾发生情况下,耐火极限为16min,涂料发泡倍数为50-60倍。     

Structure and Shape Control of Hydrothermally Synthesized PbTiO3--Effects of pH and Complexing Agents

Tabular PE-PbTiO3,spherical PY-PbTiO3,and acicular PX-PbTiO3 powders were hydrothermally synthesized from triethanolamine(TEA)-complexed precurso;clubbed PE-PbTiO3 powders were obtained from diethanolamine(DEA)-complexed precursor,The effects of pH of the hydrolyzation as well as complexing agents including TEA,DEA,and MEA(monoethanolamine) on the structure and the morphology of PbTiO3 powders are discussed.The optimal conditions for hydrothermal Synthese of acicular and clubbed PbTiO3 powders have been established.The products were characterized by means of XRD.TEM and other techniques.     

Nd0.007Gd0.993VO4晶体折射率和折射率温度系数的测量

利用自准直法,在20℃到170℃温度范围和0.4880μm、0.6328μm、1.0640μm、1.0795μm、1.3414μm等波长测量了Nd0.007Gd0.993VO4晶体的折射率,得到了这种晶体的Sellmeier方程和折射率温度系数.为了验证得到结果的可靠性,利用得到的Sellmeier方程计算1.0640μm的寻常光和异常光的折射率,并与实验测量的结果进行比较,两者的差异不大于2.2×10-4,处在测量误差的范围内.测量结果表明在室温下,对1.0640μm波长的双折射率为0.2201,双折射率温度变化率为4.3×10-6/℃.因此,与YVO4相仿,这种晶体不仅是一种优秀的激光基质材料,而且是一种优秀的双折射晶体.     

高效液相色谱法测定非离子造影剂欧乃帕克

建立了一种快速、灵敏的细径柱高效液相色谱测定非离子造影剂欧乃帕克的方法。用高氯酸去除血浆蛋白,流动相采用简单的7%（体积分数）甲醇水溶液体系。方法的线性范围为0.5~500 mg/L ,相关系数大于 0.999 8 。欧乃帕克的最低检测量为154 pg,保留时间为(3.46 ± 0.02) min,总分析时间少于5 min。日内、日间相对标准偏差(RSD)分别小于4.3%和11.4%。方法的平均回收率大于91.51%。     

Effective conductivity in isotropic heterogeneous media using a strong-contrast statistical continuum theory

The strong-contrast formulation is used to predict the effective conductivity of a porous material. The distribution, shape and orientation of the two phases are taken into account using two- and three-point probability distribution functions. A new approximation for the three-point probability function appropriate for two-phase media is proposed and discussed. Computed results for the effective conductivity using the strong-contrast formulation are compared to the Voigt and the Hashin-Shtrikman upper-bound estimates. These results show that the predicted effective conductivity is lower than both Voigt and Hashin-Shtrikman bounds. Compared to previous results using the weak-contrast formulation, the strong-contrast formulation seems to provide a better estimate for the effect of the microstructure on the conductivity.     

Kinetic and thermodynamic properties of the aerial oxidation of hydroquinone in developer solutions

The aerial oxidation kinetics of hydroquinone in a freshly prepared developer solution at different temperatures and pHs has been studied. The activation parameters, Ea, ΔG# , ΔS# , ΔH# and enthalpy of formation of activated complex, ΔHfo(X# ), are determined. The large negative value of free energy of activation ΔG# proves that hydroquinone extremely tends to be oxidized by air at optimum temperature (20℃) and optimum pH (10.5) and converts to the activated complex semiquinone. It was also found that if the pH of the developer solution is increased from 9.3 to 10.5 the reaction rate will increase by a factor of 2.     

对苯二胺类防老剂的合成

介绍和评述了合成对苯二胺类防老剂的方法及所用催化体系。参考文献３２篇。     

PREPARATION AND THEIR ANTIBACTERIAL ACTIVITY OF ACTIVATED CARBON FIBER CONTAINING SILVER*

1.INTRODUCTIONActivatedcarbonfibers(ACF)havehighspecificsurfaceareasorabundantmicropores,whichmakethemhavegreatadsorptionrateandlargeadsorptioncapacity.Nowtheymakeaveryimportantroleinenvironmentalcontrolandinresourcerecovery[1].Bytakingadvantageoftheactivatedcarbonfibers'adsorptionabilityagainstbacteriaandstenchsubstance,theycanalsobeusedinpurifyingblood,inmedicinebandageforpreventingthewoundbacteriafrompropagatingandforadsorbingandeliminatingthewoundstench.Theresultsbyotherworkersindica…     

一种商品蒸汽驱油用高温发泡剂组分剖析

对一种商品蒸汽驱油用高温发泡剂ＨＴＦＡ样品用乙酸丁酯进行萃取分离和提纯,然后对分离组分分别进行了化学分析,红外光谱分析、元素分析、核磁共振谱分析及Ｘ射线衍射分析等多种性能及结构表征实验。推断出其组份是以油溶性乳化剂烷氧基聚氧乙烯基 磺酸钠为主要成份。与水溶性助乳化剂甲基丙烯酸钠、碳酸钠、硫酸钠等复配、乳化而成。结合各组份元素定量分析结果,推断其组成比全炙主乳化剂约占乳液总重量的８％～９％,助乳化剂