马尾松、湿地松、油松针叶挥发物中手性单萜的组成与相对含量

采用动态顶空吸附／手性毛细管气相色潜-质谱（GC—MS）法,首次分析研究了马尾松（Pinus massoniana Lamb）、湿地松（Pinus elliottii Engelm）、油松（Pinus tabulaeformis Carr．）针叶挥发性化合物中主要手性单萜（α-蒎烯、莰烯、β-蒎烯、β-水芹烯、柠檬烯）的组成与相对含量,结果表明其在种间相差较大。马尾松中的（-）-α-蒎烯的含量（55．50％）最高,而其对映异构体（＋）-α／-蒎烯在油松中含量（16．86％）最高,（-）β-蒎烯在湿地松中含量（43．38％）最高。马尾松手性单萜的组成和含量在树与树间差异也较大。     

掺钕聚甲基丙烯酸甲酯的光学特性

Nd(DBM)3Phen-doped (DBM is dibenzoylmethane and Phen is phenanthroline) polymethyl methacrylate (PMMA) is prepared. Optical absorption, excitation and emission spectra were analyzed for Nd3+ in Nd(DBM)3Phen-doped PMMA. Using the Judd-Ofelt theory, the absorption spectrum was analyzed. The Judd-Ofelt(J-O) intensity parameters of Nd(DBM)3Phen-doped polymethyl methacrylate were calculated to be Ω2 = 20.97 × 10-20 cm2, Ω4 = 3.42 × 10-20 cm2, Ω6 = 2.90 × 10-20 cm2. The radiative lifetime (631 μs)of the excited 4F3/2 level is given. The stimulated emission cross-sections and the fluorescence branch ratios for the 4F3/2 →4 IJ/ transitions are also evaluated. Analysis reveals that Nd(DBM)3Phen-doped PMMA is promising for application in polymer optical fibers and planar waveguides.