Different expression systems were constructed using different expression vector including pet - his and e . coli topi of " and bl21 host cells 利用pet - his等不同表达载体和大肠杆菌top10f 、 bl21 ( de3 ) plyss表达宿主菌，成功构建了胆固醇氧化酶基因的不同原核表达系统。
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The prediction of disastrous space weather is a hot topi c among solar - terrestrial physics and high technological fields . we propose that the future forecasting of the physical conditions that the violent solar disturb ance causes at the earth by propagating in solar wind depends heavily on the num erical method . this paper analyses the existing problems we are facing in the num erical prediction of disastrous disturbance events in solar - terrestrial space , an d then gives some suggestions for future study . for such a purpose , a six step sol ution method is developed to deal with one - dimensional symmetric interplanetary shock dynamics . it should be point out that that initialization of fully self - con sistent 3 - d mhd codes considering the solar - interplanetary - geomagnetic coupled r elations with initial - boundary values at 1r of the global output of solar pl asma and magnetic field using available solar observations is an essential requi rement in space weather operational codes for forecasting purposes 空间灾害性天气的预报是日地物理学界及高科技领域的热门话题.未来预测太阳剧烈扰动所造成的行星际风暴到达地球空间的状态势必借助于数值方法.浅析了空间灾害性扰动事件数值预报存在的问题及未来设想，针对这一目的对一维球对称问题提出了处理行星际激波的6步求解方法，指出未来空间灾害性扰动事件预报模式应是一个基于三维的以真实太阳风为背景自洽建立起来的、以太阳等离子体输出及磁场全球结构为初边值、太阳、行星际、地磁因果耦合模式
