摘要：一、概述同步磁阻电动机的主要特点如下:1.转子成本比永磁转子低很多。2.每安培转矩与转子温度无关。3.定子和逆变器电力回路与异步电机或永磁同步电机驱动系统的定子和电力回路一致。4.其控制比磁场定向控制的异步电动机驱动系统简单,但需有转轴位置的反馈。5.由于分频效应(scaling effect.,小型异步电动机的效率低,转差高,故限制了交流驱动技术向更低功率等级延伸。

摘要：Au and Au-cont.ining bimet.llic nanopart.cles are promising cat.lyst. for t.e green synt.esis of fine chemicals. Here, we used a Au6Pd/resin cat.lyst.for t.e aerobic C-C cross-coupling of primary and secondary alcohols t. produce higher ket.nes under mild condit.ons. t.is is of import.nce t. t.e const.uct.on of a C-C bond. Various subst.at.s were used in t.e react.on syst.m, and moderat. t. good yields were obt.ined. t.e cat.lyst. can be reused at.least.five t.mes wit.out.decrease of yield. t.e cont.ol experiment.and XAFS charact.rizat.on result. showed t.at.hydrogen au- t.-t.ansfer occurred on met.llic Pd sit.s even under oxidat.ve condit.ons. On alloying wit. Au, t.e Pd sit.s became resist.nt.t. oxidat.on and readily abst.act.d t.e β-H of t.e alcohols and t.ansferred t.e hydride t. t.e C=C bond in t.e react.on int.rmediat. t. give t.e sat.rat.d product.

摘要：利用完全随机分组设计试验来评估不同锌浓度和锌来源对仔猪生长性能的影响。试验Ⅰ包括7个阶段．分别用蛋氨酸锌作为锌源．添加量为125、250、500mg／kg的锌来代替以氧化锌作为锌源及添加量为2500mg／kg的锌进行作用效果的比较。在所有的阶段中．以125mg／kg锌的添加量为对照组．试验选用615头猪，26个重复，平均断奶日龄是20．6d，平均初始体重6．3kg。