由镰孢菌(Fusarium spp.)引起的小麦赤霉病在全世界均有发生,我国小麦赤霉病主要由禾谷镰孢菌复合种(Fusarium graminearum species complex,FGSC)所引起,根据产生单族毒素种类分为三种化学型,分别为3-乙酰脱氧雪腐镰孢菌烯醇(3-AcDON)...由镰孢菌(Fusarium spp.)引起的小麦赤霉病在全世界均有发生,我国小麦赤霉病主要由禾谷镰孢菌复合种(Fusarium graminearum species complex,FGSC)所引起,根据产生单族毒素种类分为三种化学型,分别为3-乙酰脱氧雪腐镰孢菌烯醇(3-AcDON)、15-乙酰脱氧雪腐镰孢菌烯醇(15-AcDON)和雪腐镰孢菌烯醇(NIV)化学型。为了更方便地对禾谷镰孢菌复合种进行化学型的区分,本研究利用三对引物分别扩增了三种化学型菌株的Tri8基因并进行了序列测定,根据不同化学型菌株的基因序列差异,进行了特异性引物设计和筛选。利用设计的引物同时扩增三种化学型的Tri8基因并用AvaI内切酶进行酶切,根据酶切片段的大小区分三种化学型。研究表明该方法可准确有效地区分我国小麦赤霉病菌的化学型。展开更多
By means of ab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically ...By means of ab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically in order to study the electronic transition mechanism in Gaq3. Three derivatives of Gaq3 and their polymers were designed and the possibilities that they were employed as luminescent materials were discussed. The regularities and characteristic of energy bands of Gaq3 and its derivatives were also investigated. The results show that the electronic π-π* transitions in Gaq3 are localized on the quinolate ligands. The emission of Gaq3 is due to the electron transitions from a phenoxide donor to a pyridyl acceptor. Two possible electron transfer pathways are presented, one by carbon atoms, and the other via metal cation Ga3+. The derivatives of Gaq3 may possess high luminescence efficiency.展开更多
Degradation phenomenon and poor stability of tris（8-hydroxyquinoline） aluminum（Ⅲ）（Alq3）-based organic light-emitting diodes（OLEDs） have attracted much attention. In this paper, we discussed the origin of inst...Degradation phenomenon and poor stability of tris（8-hydroxyquinoline） aluminum（Ⅲ）（Alq3）-based organic light-emitting diodes（OLEDs） have attracted much attention. In this paper, we discussed the origin of instability of the facial Alq3-based blue luminescent OLEDs with the help of first-principles calculation. The results show that environmental humidity seriously affects the luminescence stability of Alq3-based OLEDs. H20 molecules in envi- ronment can be firmly bound to the oxygen atoms of the facial Alq3, which then act as starting points for further de- gradation of Alq3. Moreover, the interactions between facial Alq3 and different cathode metal layers were investigated to explain the experiment phenomenon. A design guideline for diminishing the strong attraction from oxygen atoms can be proposed to protect Alq3 and improve the stability of materials applied in OLEDs.展开更多
文摘由镰孢菌(Fusarium spp.)引起的小麦赤霉病在全世界均有发生,我国小麦赤霉病主要由禾谷镰孢菌复合种(Fusarium graminearum species complex,FGSC)所引起,根据产生单族毒素种类分为三种化学型,分别为3-乙酰脱氧雪腐镰孢菌烯醇(3-AcDON)、15-乙酰脱氧雪腐镰孢菌烯醇(15-AcDON)和雪腐镰孢菌烯醇(NIV)化学型。为了更方便地对禾谷镰孢菌复合种进行化学型的区分,本研究利用三对引物分别扩增了三种化学型菌株的Tri8基因并进行了序列测定,根据不同化学型菌株的基因序列差异,进行了特异性引物设计和筛选。利用设计的引物同时扩增三种化学型的Tri8基因并用AvaI内切酶进行酶切,根据酶切片段的大小区分三种化学型。研究表明该方法可准确有效地区分我国小麦赤霉病菌的化学型。
文摘By means of ab initio HF and DFT B3LYP methods, the structure of Gaq3 (q = 8-hydroxyquinoline) was optimized. The frontier molecular orbital characteristics and energy levels of Gaq3 have been analyzed systematically in order to study the electronic transition mechanism in Gaq3. Three derivatives of Gaq3 and their polymers were designed and the possibilities that they were employed as luminescent materials were discussed. The regularities and characteristic of energy bands of Gaq3 and its derivatives were also investigated. The results show that the electronic π-π* transitions in Gaq3 are localized on the quinolate ligands. The emission of Gaq3 is due to the electron transitions from a phenoxide donor to a pyridyl acceptor. Two possible electron transfer pathways are presented, one by carbon atoms, and the other via metal cation Ga3+. The derivatives of Gaq3 may possess high luminescence efficiency.
基金Supported by the National Natural Science Foundation of China（Nos.61307119, 61235004）.
文摘Degradation phenomenon and poor stability of tris（8-hydroxyquinoline） aluminum（Ⅲ）（Alq3）-based organic light-emitting diodes（OLEDs） have attracted much attention. In this paper, we discussed the origin of instability of the facial Alq3-based blue luminescent OLEDs with the help of first-principles calculation. The results show that environmental humidity seriously affects the luminescence stability of Alq3-based OLEDs. H20 molecules in envi- ronment can be firmly bound to the oxygen atoms of the facial Alq3, which then act as starting points for further de- gradation of Alq3. Moreover, the interactions between facial Alq3 and different cathode metal layers were investigated to explain the experiment phenomenon. A design guideline for diminishing the strong attraction from oxygen atoms can be proposed to protect Alq3 and improve the stability of materials applied in OLEDs.
