查詢結果分析
相關文獻
頁籤選單縮合
題 名 | Reaction of Y(Ba Sr )Cu[feb0]Oy with Water |
---|---|
作 者 | 林晴煌; 高惠春; | 書刊名 | Journal of the Chinese Chemical Society |
卷 期 | 49:5 2002.10[民91.10] |
頁 次 | 頁867-873 |
分類號 | 346.01 |
關鍵詞 | Superconductors; Kinetics; YBa Sr Cu[feb0]Oy; Activation energy; Reaction rate; |
語 文 | 英文(English) |
英文摘要 | Reaction of superconducting Y(Ba□Sr□)Cu□O□ (abbreviated as YS-123) power with water in a closed system at pH 7 and 25℃, after 150 h, the concentration ratio of Y:Ba:Sr:Cu ion in the solution is 0.0025:1:0.33:0.0003. Mass equation of the reaction is similar to that of YBa□Cu□O□ (abbreviated as Y-123). Leaching rate of the Ba ion is higher than that of the Sr ion at the beginning of the reaction, which reflects the basicity difference between these two alkaline earth elements. The initial rate equation is expressed as R□=k[S]□[H□O□]□. [S]□ is the initial surface area of YS-123 powder and H□O□ a catalyst, a and b are found to be 0.99 ± 0.02 and 0.58 ± 0. 02, respectively. The initial rate, R□, for 100,1 mg powder with a mean radius of 0.025 mm at pH 7 and 25℃ is 1.35×10□mol.min□. Rate constant, k, is (0.54±0.03), (1.1 ± 0.1) and (1.90±0.08) × 10□mol.min□.cm□.M□ for the reaction at 10, 25 and 40℃, respectively, by using a=1 and b=0.6 for calculation. Activation energy (E□) and pre-exponential factor (A) calculated from the Arrhenius equation are 31.2±0.4 kJ.mol□ and (3.0±0.4)×10□mol.min□.cm□.M□. Although the amount of Sr substitution to Ba is only 25﹪, initial reaction rate of YS-123 in water is 2 orders magnitude smaller than that of Y-123 at pH 7. |
本系統中英文摘要資訊取自各篇刊載內容。