排序方式： 共有2条查询结果，搜索用时 15 毫秒
1
1.
采用反相高效液相色谱法同时测定化妆品中7种苯甲酸酯类化合物的含量。样品(约0.5g)用8mL甲醇超声提取30min,冷却后,用甲醇定容至10mL。移取部分溶液以5 000r·min~(-1)转速离心5min,上层清液经有机相针式过滤头过滤。以ECOSIL 120-5-C30色谱柱为分离柱,以甲醇(6+4)溶液为流动相,在测定波长229nm处进行测定。7种苯甲酸酯类化合物的质量浓度均在1.25～50.00mg·L~(-1)内与其对应的峰面积呈线性关系,方法的测定下限(10S/N)为4～8mg·kg~(-1)。以空白样品为基体进行加标回收试验,所得回收率为88.8%～97.2%,回收量的相对标准偏差(n=6)为2.2%～5.3%。 相似文献
2.
This paper presents a reduced-order model to describe the mechanical behaviour of microbeam-based magnetic devices. The integration for magnetic force is calculated by dividing the microbeam into several segments, and the nonlinear equation set has been developed based on the magnetic circuit principle. In comparison with previous models, the present macromodel accounts for both the micro-magnetic-core reluctance and the coupling between the beam deflection and magnetic force. This macromodel is validated by comparing with the experimental results available in some papers and finite-element solutions. 相似文献
1