http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
윤성호,이호진,이강봉,Yun, Seong Ho,Lee, Ho Jin,Lee, Gang Bong Korean Chemical Society 2000 Bulletin of the Korean Chemical Society Vol.21 No.9
[FeIII(BBA)DBC]ClO4 as a new functional model for catechol dioxygenases has been synthesized, where BBA is a bis(benzimidazolyl-2-methyl)amine and DBC is a 3,5-di-tert-butylcatecholate dianion.The BBA complex has a structuralfeature that iron cent er has a five-coordinate geometry similar to that of catechol dioxygenase-substrate complex.The BBA complex exhibits strong absorptionbands at 560 and 820 nm in CH3CN which are assigned to catecholate to Fe(III) charge transfer transitions. It also exhibits EPR signals at g = 9.3 and 4.3 which are typical values for the high-spin FeIII (S = 5/2) complex with rhombicsymmetry. Interestingly, the BBA complex reacts with O2 within an hour to afford intradiol cleavage (35%) and extradiol cleavage (60%) products. Surprisingly, a green color intermediate is observed during the oxygenation process of the BBA com-plex in CH3CN. This green intermediate shows a broad isotropic EPR signal at g = 2.0. Based on the variable temperature EPR study, this isotropic signalmight be originated from the [Fe(III)-peroxo-catecholate] species havinglow-spin FeIII center, not from the simple organic radical. Consequently,it allows O2 to bind to iron cen-ter forming the Fe(III)-superoxide species that converts to the Fe(III)-peroxide intermediate. These present data can lead us tosuggest that the oxygen activation mechanism take place for the oxidative cleavingcatechols of the five-coordinate model systems for catechol dioxygenases.
액정구조가 셀룰로오스 섬유의 역학적 성질에 미치는 영향
윤성호,강태진,김선경,Yun, Seong-Ho,Gang, Tae-Jin,Kim, Seon-Gyeong 한국섬유공학회 1989 한국섬유공학회지 Vol.26 No.6
Cellulose powders were dissolved in the mixture of liquid ammonia and ammonium thiocyanate at room temperature. The cellulose solutions at the mesomorphic concentration were extruded into methanol bath by the dry-wet spinning condition. The tenacity and initial tensile modulus of the fiber increased with the anisotropic phase volume fraction of the solution but decreased with the specific layer birefringence of the mesomorphic solution. The spinning test results showed that the cellulose anisotropic phases were easily deformed by shear deformation that it indicates high potential for spinning this mesomorphic solution into a highperformance cellulosic fibers.