控制系统周期性任务调度中优化采样频率的求职

文章分析了控制系统中任务的特点，根据任务调度中系统性能与采样频率的关系，指出了控制系统优化中任务调度应满足的条件，基于这些条件，文章给出了优化采样频率的求解方法和算法。     

Laser multi-layer classing of Mg-based alloys

By laser multi-layer cladding using a pulsed Nd-YAG irradiation the thickness of the cladding zone Mgbased alloys(ZM2 and ZM5)can reach about 1.0mm.The microstructure of the substrate and the classing zone was studied using optical microscope.scanning electron microscopy(SEM),X-ray diffractometry(XRD0and micro hardness analysis.It is observed that constituent of ZM5 alloy is δ Mg17Al12,that of ZM2 alloy is α MgZn Mg9Ce.That of cladding layer ZM2 alloy(L-ZM2)is Mg Mg2 Zn11 MgCe;while that of the cladding layer ZM5 alloy(LZM5)is Mg Mg32（Al,Zn)49,The hardness of the cladding area can be increased to values above HV127.Very fine uniform microstructure and the produced new phases of nanometer/sub-micrometer order were obtained.Now,many repaired Mg-based alloy components have been passed by flying test in outside field.     

环形竖炉焙烧硫酸渣球团矿的生产实践

简要介绍硫酸渣生产球团矿的工艺流程和技术特点。     

Observation of atomic steps on CaCO3 crystal surface

By using scanning polarization force microscopy,the deliquescence process and the atomic steps on the cleavage surface of CaCO3 in air were studied in situ.Under an exposure to medium umidity(-57%),the sloiw step movement has been observed.     

特殊多功能营养保健饮品——“力恩”的研制

特殊多功能营养保健饮品──“力恩”的研制郑九芳，陈秀英，杨朝晖（浙江省温州天恩保健食品有限公司瑞安市，３２５２０７）一、综述八十年代以来，国外保健品发展速度为食品行业之首，至今方兴未艾，而且品种繁多，美国现有健康食品企业５３０家，产品达一万多种，８８...     

微生物产生的功能食品添加剂——PUFAs

微生物产生的功能食品添加剂──ＰＵＦＡｓ李东，孙健，彭沈军（北京市营养源研究所生物工程高技术室北京，１０００５４）一、前言微生物脂类是具有不同性质和重要生化功能的化合物。利用生物工艺开发微生物脂类产品，必须考虑与从农业资源获得的类似产品竞争。可与植物...     

一种转差频率控制的变频调速系统

本文介绍了采用通用变频器实现转速，转差频率双闭环调整系统控制结构，在实现基础上对起动过程进行了分析。