Pseudo-steady-state solutions for solidification in a wedge

Polubarinova-Kochina's analytical differential equation methodis used to determine the pseudo-steady-state solution to problemsinvolving the freezing (solidification) of wedges of liquidwhich are initially at their fusion temperature. In particular,we consider four distinct problems for wedges which are: freezingwith the same constant boundary temperature, freezing with thesame constant boundary heat fluxes, freezing with distinct constantboundary temperatures and freezing with distinct constant fluxesat the boundaries. For the last two problems, a Heun's differentialequation with an unknown singularity is derived, which in bothcases admits a particularly elegant simple solution for thespecial case when the wedge angle is . The moving boundariesobtained are shown pictorially.     

新技术驱动雷击测试标准的发展

飞机新技术的发展,使人们必须重新审视飞机的雷击测试方法,以确保其耐受性。2007年12月,航空无线电技术委员会（RTCA）的飞机电磁兼容测试标准DO 160最新版F版发表,而欧洲民航设备组织（EUROCAE）也发布了与其等效的文件ED14。     

HPLC法测定藿香正气颗粒中的厚朴酚

目的:建立厚朴制剂藿香正气颗粒中厚朴酚含量测定的HPLC法。方法:采用甲醇溶解样品超声制备供试液;HPLC色谱条件为:Zorbax RP-C18色诸柱(150mm×4.6mm,5μm);流动相:甲醇-水(80:20,v/v);流速:1.0mL/min;检测波长:294 nm。结果:厚朴酚的线性范围是0.02至4μg/mL,其线性相关系数R=0.9992,藿香正气颗粒中厚朴酚的含量为0.273mg/袋,其厚朴酚加样回收率为99.2%至101.4%,RSD为1.73%。结论:此方法快速简便,可用于评价藿香正气颗粒的质量。