提出基于图论的微机母线保护装置保护区选择新方法。用典型母线布置说明如何用图论法表示变电站结线布置,并进行图解运算和相关矩阵运算。阐述保护区选择方法的实现过程,并用2个示例说明这种方法的优点。该技术为保护装置提供开关状态...提出基于图论的微机母线保护装置保护区选择新方法。用典型母线布置说明如何用图论法表示变电站结线布置,并进行图解运算和相关矩阵运算。阐述保护区选择方法的实现过程,并用2个示例说明这种方法的优点。该技术为保护装置提供开关状态及母线结线状态的实时信息。母线保护利用这些信息确定差动保护区的电流分布,选择母线故障或开关故障时应跳掉的开关。本文摘译自《IEEE Transactions on Power Delivery》 2000,15(3)的“A NewMethod for Protection Zone Selection in Microprocessor-Based Bus Relays”一文,以供参考。展开更多
Mangiferin is a natural plant polyphenol with a structure of xanthone C-glycoside and it displays a wide spectrum of pharmacological activities. Investigation of the metabolites of mangiferin is valuable in studying t...Mangiferin is a natural plant polyphenol with a structure of xanthone C-glycoside and it displays a wide spectrum of pharmacological activities. Investigation of the metabolites of mangiferin is valuable in studying the mechanisms of its various pharmacological properties and developing novel drugs from the mangiferin derivatives. Among the metabolites of mangiferin, mangiferin-7-O-β-D-glucuronide has been reported as the phase Ⅱ metabolite of mangiferin. Herein we described the first semi-synthesis of mangiferin-7-O-β-D-glucuronide with the natural product mangiferin as the starting material. In this work, we adopted several regioselective protection procedures to distinguish the different hydroxyl groups in the structure of mangiferin, and we accomplished the glycosylation under the phase-transfer catalysis conditions. In this method, we efficiently synthesized the glucuronide derivative of mangiferin in 10 steps with highly regioselective protection.展开更多
文摘提出基于图论的微机母线保护装置保护区选择新方法。用典型母线布置说明如何用图论法表示变电站结线布置,并进行图解运算和相关矩阵运算。阐述保护区选择方法的实现过程,并用2个示例说明这种方法的优点。该技术为保护装置提供开关状态及母线结线状态的实时信息。母线保护利用这些信息确定差动保护区的电流分布,选择母线故障或开关故障时应跳掉的开关。本文摘译自《IEEE Transactions on Power Delivery》 2000,15(3)的“A NewMethod for Protection Zone Selection in Microprocessor-Based Bus Relays”一文,以供参考。
基金The National Research Foundation for the Doctoral Program of Higher Education of China(Grant No.20130001110058)
文摘Mangiferin is a natural plant polyphenol with a structure of xanthone C-glycoside and it displays a wide spectrum of pharmacological activities. Investigation of the metabolites of mangiferin is valuable in studying the mechanisms of its various pharmacological properties and developing novel drugs from the mangiferin derivatives. Among the metabolites of mangiferin, mangiferin-7-O-β-D-glucuronide has been reported as the phase Ⅱ metabolite of mangiferin. Herein we described the first semi-synthesis of mangiferin-7-O-β-D-glucuronide with the natural product mangiferin as the starting material. In this work, we adopted several regioselective protection procedures to distinguish the different hydroxyl groups in the structure of mangiferin, and we accomplished the glycosylation under the phase-transfer catalysis conditions. In this method, we efficiently synthesized the glucuronide derivative of mangiferin in 10 steps with highly regioselective protection.
