直到不久前模拟器还只能模拟稳定过程，但是现在很多都可以在动态情况下，比如说过程的波动期来模拟一些复杂的操作过程。
Until recently simulators could only simulate processes at steady-state conditions, but now many can simulate complex operations in dynamic situations such as during process fluctuations.
介绍了大型合成氨厂低变炉更换催化剂的过程；论述了催化剂的选型要求和装填方法；阐明了催化剂还原过程中从还原前升温到还原初期、主期及末期的操作步骤和要求。
The process to replace the catalyst of shifting furnace was introduced for large-sized ammonia synthesis plant; the requirements of type selection and filling method for catalyst were discussed.
结论开展实习前的强化训练，有助于提高实习生外科基本操作技能，增强动手能力，缩短进入临床实习的适应期。
Conclusion it's helpful for interns to improve the surgical performance skill, enhance the operation ability, and shorten the period of adaptation before practice in the hospital.
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