盛夏西太平洋副热带高压对陕西降水的影响

利用1961-2008年陕西78个气象站7-8月降水资料、西太平洋副高逐月指数资料及500hPa位势高度场和700hPa风场月平均再分析资料,通过相关、回归分析、小波凝聚谱分析等方法探讨盛夏西太平洋副热带高压对陕西降水的影响及机制,为盛夏陕西降水的气候预测提供依据.结果表明,盛夏副高强度、脊线、西伸脊点指数与陕西降水关系密切,副高偏强偏西时陕西降水偏多,副高偏北时陕西北部降水偏多、南部偏少.8月副高3个指数与陕西降水的相关关系更为密切,通过显著性检验的站点明显增多.副高的强度和位置变化引起副热带和中高纬度大气环流的异常,进而影响陕西降水.8月副高偏强偏西时,巴尔喀什湖阻高增强,700hPa西南季风的水汽输送增强,陕西位于冷暖空气交汇区,降水偏多;副高偏南时,水汽辐合区位于陕南,陕西南部多雨、北部少雨;副高偏北时,水汽辐合区位于陕北,陕西北部多雨、南部少雨.8月副高强度指数与同月陕西降水的显著共振周期为7 ～8a,且副高强度变化超前于陕西降水变化1.26a,说明8月副高强度的年际变化是引起同月陕西降水年际变化的重要原因.     

银松素类衍生物分子的几何结构和光谱性质

采用密度泛函理论(Density functional theory,DFT)方法研究了7个银松素衍生物分子的结构和光谱性质。在B3LYP/6-311G**理论级别上优化了它们的几何结构,通过频率计算拟合了分子的红外振动光谱:具有共轭芳烃特征的银松素衍生物体系在1650~1450cm-1具有高红外活性的苯环伸缩振动峰,而双键在1690cm-1附近的特征伸缩振动是偶级对称振动,不产生高强度红外光谱吸收峰;在高频区(3830cm-1)观察到羟基的O-H键伸缩振动谱带。采用含时密度泛函理论(Time-dependent Density functional theory,TD-DFT)方法和极化连续介质模型(Polarized Continuum Model,PCM)计算了上述分子在CHCl3溶液中的电子吸收光谱,计算揭示吸收谱带以π→π*跃迁为主,羟基和甲氧基的引入仅起修饰作用。     

黄麻和红麻纤维磨木木质素的红外光谱特征

从黄麻和红麻纤维中分离出磨木木质素,利用红外光谱分析了两种麻纤维磨木木质素的特征峰及归属,得知磨木木质素中有复杂的官能团,含有羟基、羰基、甲基等基团,木质素结构中含有相当数量的紫丁香基单元。根据黄麻和红麻纤维磨木木质素的红外光谱吸收峰强度,推断其结构属于阔叶木类木质素化学结构GS型木质素。     

基于杠杆率校正的PLS-DA法对正半岩武夷岩茶的识别研究

武夷岩茶属于闽北乌龙茶,是福建省的特有茶类,也是我国传统名茶中的精品,尤其以武夷中心地带所产的正岩茶品质最佳。本文采用近红外光谱技术,利用杠杆率校正(leverage correction)结合偏最小二乘法(Partial least Squares Discriminant Analysis,PLS-DA)的分析方法,进行了武夷岩茶中的正岩茶与半岩茶的分类识别研究。结果表明不仅定标集42个样本的识别正确率为100%,对于未参与模型建立的验证集20个样本的识别正确率也达到了100%。初步证明了利用近红外技术结合PLS-DA分析方法对正岩茶与半岩茶进行分类识别的可行性。     

镉胁迫下泥鳅肝脏的红外光谱研究

重金属胁迫能引起机体内生理生化的变化,而组织和细胞的变化总是从分子开始,因此在组织和细胞变化的过程中,蛋白质、脂类、碳水化合物和核酸等构成组织和细胞的主要物质、含量、构型、构象分子间及分子内相互作用等方面都会发生变化。这些变化可以从发生变化的组织和正常组织红外光谱的谱图比较上反映出来。为此,笔者利用傅立叶变换红外光谱技术对不同浓度Cd^2＋处理下泥鳅肝脏组织和正常泥鳅肝脏组织进行研究,以期为研究镉对泥鳅的毒害作用提供新方法。     

Structural changes in lignin of tropical woods during digestion by termite, <Emphasis Type="Italic">Cryptotermes brevis</Emphasis>

Wood samples of apitong (Dipterocarpus grandiflorua) and ilang-ilang (Ilang-Ilang C. dadloyi) and feces of termites [Cryptotermes brevis (Walker)] fed on these woods were collected from University of the Philippines, Los Baňos. Lignin of each sample was isolated by Björkman’s procedure. There was no significant difference in ¹H nuclear magnetic resonance (NMR) spectra or in the methoxyl content between Björkman lignins from original woods and termite feces. Differences were detected in the contents of aliphatic and unconjugated phenolic hydroxyl groups, suggesting minor structural changes of lignin during digestion by termites. In addition, the ratio of syringyl to guaiacyl nuclei of Björkman lignin from termite feces determined by ¹H NMR spectra was higher than those from the original woods. The molar ratio of syringyl to guaiacyl nuclei of termite feces was higher than those from the original woods as determined by alkaline nitrobenzene oxidation. These results suggest that the structural changes of lignin in the termite gut are due to the insignificant formation of C-C linkages in guaiacyl nuclei. It was concluded that there were minor changes in the structural features of lignin under mostly anaerobic conditions, in contrast to the significant changes that occur through biological modification under aerobic conditions.     

超高产杂交稻剑叶的光抑制及其77K荧光光谱特性

通过对培矮64S/E32和汕优63进行高光胁迫结果表明: 与籼型杂交稻汕优63比较, 培矮64S/E32的Fv/Fm和ΦPSⅡ、PSⅡ和PSⅠ荧光强度下降的幅度以及F685/F742和F694/F742比率的变化较小。用D1蛋白合成抑制剂CAP处理时,培矮64S/E32 的Fv/Fm和qP下降程度稍高于汕优63,而用叶黄素循环抑制剂DTT处理,结果则反之。表明超高产水稻品     

Study on the Absorption Spectra and Stability of Theaflavin Pigment

Theaflavin(TF) was extracted and purified from black broken tea. The purified TF possessed an absorption peak at the 363nm wavelength, and the solutions of TF remained stable under the conditions of pH3-6, below 80℃ within 60 minutes, as well as in 1%-4% Vc and 0.05-0.5mmol/L Na2SO3 solutions. Fading occurred in 0.05mol/L H2O2 solution.     

Postulation of leaf-rust resistance genes in Czech and Slovak barley cultivars and breeding lines

Leaf‐rust resistance (Rph) genes in 61 Czech and Slovak barley cultivars and 32 breeding lines from registration trials of the Czech Republic were postulated based on their reaction to 12 isolates of Puccinia hordei with different combinations of virulence genes. Five known Rph genes (Rph2, Rph3, Rph4, Rph7, and Rph12) and one unknown Rph gene were postulated to be present in this germplasm. To corroborate this result, the pedigree of the barley accessions was analysed. Gene Rph2, as well as Rph4, originated from old European cultivars. The donor of Rph3, which has been mainly used by Czech and Slovak breeders, is ‘Ribari’ (‘Baladi 16’). Rph12 originates from barley cultivars developed in the former East Germany. Rph7 in the registered cultivar ‘Heris’ originates from ‘Forrajera’. A combination of two genes was found in 10 cultivars. Nine heterogeneous cultivars were identified; they were composed of one component with an identified Rph gene and a second component without any resistance gene. No gene for leaf rust resistance was found in 17 of the accessions tested. This study demonstrates the utility of using selected pathotypes of P. hordei for postulating Rph genes in barley.     

主成分──逐步回归法在近红外光谱定量分析中应用的研究

本文使用一种新的多元统计建模方法：主成分——逐步回归法,用于近红外光谱定量分析中,其预测精度接近偏最小二乘法．