阀门定位器二○○○年的振兴目标

本文选取我国ZPO-OlA型电-气阀门定位器与美国FOXBORO公司F69P型电-气阀门定位器进行分析对比,根据有关资料和加权评分方法,对我国阀门定位器产品水平作出评价,找出了差距,并提出了发展目标和建议措施。     

Coercivity Mechanism of Melt-spun Nd-Fe-B Bonded Magnet

The microstructures of melt-spun Nd_135-Fe_81.74B4.76 ribbons have been investigated bymeans of X-ray diffraction,Mossbauerspectroscopy and HREM.Experimental resultsshow that optimal magnetic properties of the bond-ed magnet can be obtained by melt-spun alloys atwheel velocity of 24m/s,the microstructure ofwhich was single phase Nd_2Fe_(14)B crystallites,andno other phases,such as Nd-rich,B-rich or x-Fephase,were present.It is considered that the highintrinsic coercivity ~iH_c can be attributed to the sin-gle-domain behaviour of Nd_2Fe_(14)B crystallitephase.     

喷射成形Cu—15Ni—8Sn合金的显微组织与性能

采用喷射成形技术制造Ｃｕ１５－Ｎｉ－８Ｓｎ合金，检验其显著微组织和性能，并与铸造合金进行比较。结果表明，喷射成形的Ｃｕ－１５Ｎｉ－８Ｓｎ合金有十分细小的等轴晶粒，化学成从非常均匀。     

具有节能效益的非线性反馈阀门定位器

介绍了一种非线性反馈阀门定位器,指出它可用来补偿调节阀在低压降比运行时流量特性曲线的畸变,使调节阀具有良好的直线和等百分比工作流量特性,达到节能的目的。文中还给出了该产品的主要技术指标,介绍了产品特点和应用效果。