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易化运输机制下的膜运载动力学的基本方程 被引量:3
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作者 李泉 《数理医药学杂志》 1995年第1期7-10,共4页
各种膜的性质是一个进行广泛研究的题目。有许多分子,特别是各种代谢物质,如糖类和氨基酸,并不遵循Firk定律。本文将提出物质通过细胞膜进入细胞进行营养运输的不遵循Firk定律方式的易化运输过程,给出它的动力学基本方程和某些结论,并... 各种膜的性质是一个进行广泛研究的题目。有许多分子,特别是各种代谢物质,如糖类和氨基酸,并不遵循Firk定律。本文将提出物质通过细胞膜进入细胞进行营养运输的不遵循Firk定律方式的易化运输过程,给出它的动力学基本方程和某些结论,并指出膜运载动力学的发展前景。 展开更多
关键词 易化运输 细胞膜 营养摄取率 膜运载动力学
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竞争性抑制系统中的膜运载动力学方程 被引量:3
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作者 李泉 《数理医药学杂志》 1997年第4期289-290,共2页
在易化运输机制下,基质的摄取可能被合用同一运载系统的其它营养物质所抑制,即抑制剂Ⅰ的加入,扰乱了载体T和复合物ST之间的平衡,抑制剂Ⅰ和底物S的结合产生竞争性抑制。本文将首次导出此竞争性抑制系统的膜运载动力学方程。
关键词 易化运输 膜运载动力学 竞争性抑制系统
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非竞争性抑制系统中的膜动载动力学方程 被引量:1
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作者 李泉 《数理医药学杂志》 1999年第4期289-290,共2页
在易化运输机制下,若抑制剂I的加入并不扰乱载体T 和ST 之间的平衡,即I可结合到T 和ST上,S也可以结合到T和ST 上,则S和I不互相排斥。
关键词 易化运输 膜运载动力学 非竞争性 抑制系统
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China introduces the 24-hour rule
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作者 Bergami Roberto 《Chinese Business Review》 2009年第3期1-7,共7页
Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand cu... Recently, international movement measures that may be causing tension between the of cargo had been the subject of increasing border control needs for security and the needs for trade facilitations. On the one hand customs authorities are charged with the responsibility for policing a country's borders, and consequently they need to have in place measures to ensure that only legitimate trade takes place and that this trade does not present security concerns. On the other hand we have the requirements of traders, who benefit from an environment of trade facilitation with speedy and efficient movement of cargo across international borders, with minimal bureaucratic intervention. This paper focuses on and provides early discussion and comments on the possible ramifications of the introduction of the 24-hour rule in China, effective for all exports and imports of sea freight container traffic since January 1, 2009. The new rules will have significant impact on the logistics flows of exporters and importers alike. Specifically, the reporting requirements timelines are likely to result in increased costs in cargo processing at wharves that traders will have to bear; place added pressure on storage facilities at wharves, or at container depots; and may additionally increase the amount of inventory buffer because of the timing of the data reporting requirements. The paper concludes that security needs have prevailed over trade facilitation considerations and that traders should urgently implement a review of existing practices to ensure they comply with the China Customs requirements, whilst simultaneously minimizing cost increases. 展开更多
关键词 24-hour rule cargo security ANTI-TERRORISM international regulations China Customs
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