排序方式: 共有8条查询结果,搜索用时 109 毫秒
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高效液相色谱法测定葡萄叶中5种芪化物 总被引:3,自引:0,他引:3
建立了同时检测葡萄叶片中白藜芦醇(resveratrol,Res)、云杉苷(piceide,PD)、ε-葡萄素(ε-viniferin)、δ-葡萄素(δ-viniferin)、紫檀芪(pterostilbene,PS)5种芪化物的高效液相色谱分析方法.采用Atlantis C18色谱柱 (250 mm×4.6 mm, 5 μm), 流动相为乙腈、水梯度洗脱,二极管阵列检测器,检测波长为306 nm;流速1 mL/min; 柱温30 ℃,外标法定量.结果显示: 5种芪化物的线性关系良好,相关系数在0.9990~0.9996之间;精密度、稳定性的RSD都低于5%;平均回收率为90.3%~114.0%,检出限为0.01~0.05 mg/L.本方法前处理简单、快速.应用本方法测定了葡萄叶片紫外诱导后5种芪化物的含量变化,结果令人满意. 相似文献
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本文比较了带干扰的两类不同风险模型.首先研究了在不同保费计算原理下各风险业务的相关性是如何影响保费率计算的,进而通过鞅方法推导出两类模型破产概率的Lundberg指数和Lundberg不等式,最后比较了在不同保费计算原理下两类模型的Lundberg指数的性质. 相似文献
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复合二项过程下的负风险模型 总被引:2,自引:0,他引:2
本文研究了总索赔服从复合二项过程的负风险模型.通过鞅方法推导出了该模型破产概率的Lundberg不等式和破产概率的精确表达式. 相似文献
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In this article, the authors consider the optimal portfolio on tracking the expected wealth process with liquidity constraints. The constrained optimal portfolio is first formulated as minimizing the cumulate variance between the wealth process and the expected wealth process. Then, the dynamic programming methodology is applied to reduce the whole problem to solving the Hamilton-Jacobi-Bellman equation coupled with the liquidity constraint, and the method of Lagrange multiplier is applied to handle the constraint. Finally, a numerical method is proposed to solve the constrained HJB equation and the constrained optimal strategy. Especially, the explicit solution to this optimal problem is derived when there is no liquidity constraint. 相似文献
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