TRANSIENT RESPONSE OF FLEXIBLE ROTOR WITH ACTIVE MAGNETIC BEARINGS DURING ROTOR DROP

11ntroductionAnactivemagneticbearing(AMB)isanewandhightechnologyforactivevibrationcontrol.Itisbeingusedinindustrialrotatingmachinerysuchascentrifugalcompressorsandpumpswithhighperformances-Ingeneral,amagneticbear-ingsystemneedsabackuprotorsupportsystem-backupbearingsincasethatAMBsystemfailsorthemachinedoesnotoperate.Abackupbear-ing,whichisalsocalledan"auxiliarybearing"ora"catcherbearing",isarollingelementbear-inglocatedattheouter-boundofAMB.Beingassembledonthestator,thebackupbearingisnotac…     

Numerical analysis of acoustic band gaps in two-dimensional periodic materials

Using the plane-wave expansion （PWE） method , the band gaps of the two-dimension phononic crystals composed of square, triangle and honeycomb arrays aluminum cylinders in the air are calculated numerically. The band structures of three lattices were compared and analyzed. It is concluded that the band-gap of honeycomb lattices is located at lower frequency fields, compared with square and triangle lattices, When the filling fraction is between 0. 091 and 0. 604 6, the honeycomb lattices have larger band gaps and gain an advantage over square and triangle lattices. In addition, the gap map is introduced to illustrate the influences of filling fraction on the number, the relative width and the limit frequency of the band-gap.     

试析商业广告中的女性形象及社会意义

女性形象在商品广告中占有很高比例,但是角色单一,模式固定,形象刻板,仍然在一定程度上存在着男性话语权主宰的话语环境特征.本文试图通过对广告中女性形象的解析,与传统意义上女性形象进行类比,从广告中的男本位视角探讨男权意识的强化和新特点,以及对两性关系的定位,女性自我意识,儿童性别意识的影响.     

高精度GPS差分定位技术辅助海上试验研究

越来越多的海上实船试验，对海上定位和测距的精度提出了更高的要求。此文利用国际先进的GPS接收机以及无线电数据传输系统组成了高精度差分卫星全球定位系统，实现达到1m(SEP)的实时动态高精度定位。同时利用时间同步模块，解决了海上试验的时统技术，在各种海上试验中发挥了重要的作用。     

“中国意志”携手上海巴富仕角逐35届美洲杯帆船赛

中国意志（China Spirit）与上海巴富仕游艇俱乐部携手，在旧金山－上海姐妹城市委员会的支持下，宣布参与角逐第35届美洲杯帆船赛以及明年举办的青年红牛美洲杯帆船赛。     

Wanlass电动机的电磁分析与节能研究

运用电机基本原理推导出Ｗａｎｌａｓｓ电动机的基本方程式和等效电路。对Ｗａｎｌａｓｓ电动机的节能效果进行了分析，从电磁分析角度看不能得了Ｗａｎｌａｓｓ电动机有节能效果的结论。