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"雏鹰"展翅     
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《国际航空》2011,(6):1-1
20年前.当国外商用飞机制造商预测,中国航空运输市场的规模在20年后将紧随美国,成为世界第二大航空市场的时候,很多人都认为这不过是制造商们的-厢情愿.但今天的事实证明.这个预测并不为过.  相似文献   

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安世亚太和苏氏集团正式结为战略联盟,利用各自的优势打造集成"精益研发技术+精密铸造工艺"的工业再设计体系。战略联盟的建立将安世亚太精益研发、工程仿真技术与苏氏精密铸造工艺相结合,启动工程仿真驱动的工业再设计过程,让设计突破工艺局限,敢于跨量级优化,并产生颠覆式创新。  相似文献   

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孙茂  吴礼义 《航空学报》1989,10(3):198-199
 最近杨岞生教授和J.C.Wu教授提出了一种跨音速流的边界积分法。该方法以脉冲压强为基础建立非线性可压缩位流的边界积分表示式,利用边界元法给出了二维、三维机翼跨音速位流的计算方法。我们认为文献[1]在推导该方法的基本方程(即主管脉冲压强的方程)和求此方程的基本解这两个方面存在一些问题。  相似文献   

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The properties of Alfvén waves generated in the photosphere by field lines trapped in vortex sinks and propagating upwards through the transition region and corona are discussed and contrasted to those of waves generated via reconnection in transition region explosive events, or rather via untwisting reconnecting flux tubes. An outline for future simulations and theoretical advances necessary to understand the dynamics of spicules and macrospicules is described, and a detailed search for photospheric velocity patterns underlying macrospicules is suggested. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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A finite element model of the Z-crimp shaping from a hard sheet blank is developed and a number of calculations using the ANSYS finite element software is conducted. The calculations are carried out in the framework of elastoplastic behavior of the blank material using the classical model of bilinear kinematic (translational) hardening with corresponding parameters of elasticity and plasticity. The model takes into account kinematics of spatial transformation of the shaping equipment as well as the time-variable conditions of its contact interaction with the blank.  相似文献   

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吴望一 《航空学报》1989,10(3):200-202
 近年来,杨岞生、吴镇远提出了一种新的解决非线性可压缩流的边界元法,他们在引进压力冲量之后将一个非线性问题转变为线性问题,然后利用边界积分表示式给出了二维、三维机翼跨音速绕流的计算方法。若干数值算例说明该方法的结果与其它数值方法和实验结果相比符合得较好。由于该方法能够将一个非线性可压缩位势流转换为对压力冲量的线性方程,因此理所当然地引起了国内外学者的关注。  相似文献   

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The following topics are dealt: career development definition; career development as a part of effective management; job satisfaction issues; motivated abilities; a case study results; identification of motivational patterns; and 'reinvention' of career development  相似文献   

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 采用无机溶胶-凝胶法制备VO2相变薄膜,该薄膜相变时的电阻(率)突变可达4~5个数量级。并用XRD,DSC和TGA法研究了制膜过程中干凝胶膜的层状非晶纳米结构。通过适当的非晶晶化过程及随后V2O5→VO2转变的真空热处理,可获得带有空洞(void)结构的低密度纳米薄膜,从而使电阻(率)突变特性异常优异。  相似文献   

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Cars powered by fuel cells have been built and tested; however, the aerospace fuel cells could not deliver high power quickly when the driver wanted to accelerate his car. Today's hybrid electric cars carry a battery that supplies the acceleration power, and the prime power source, whether an engine or fuel cell, is not stressed with sudden load peaks. Zero air pollution becomes attainable when fuel-cells supply the prime power on a hybrid vehicle  相似文献   

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