目标微动参数估计的曲线跟踪算法

对于包含多散射点的微动部件来说,其微动参数估计等价于多分量非平稳信号的瞬时频率估计.针对此问题,提出一种基于曲线跟踪算法的目标微动参数估计方法.该算法首先在时频域通过最近邻数据关联算法分离各分量信号的时频曲线,然后,采用扩展Kalman滤波器对各时频曲线进行平滑滤波,并基于平滑后的时频曲线估计目标微动参数.基于电磁计算数据的仿真结果验证了该算法的有效性.     

金属多面体上低剖面天线的矩量法分析

采用矩量法对任意形状导体上的低剖面天线进行了整体分析,其中导体采用三角形面元矢量基函数、细线结构采用三角形基函数、线面连接处采用特殊的基函数,在处理积分奇异时,通过坐标变换、积分转化、降维处理实现了奇异积分的精确快速计算,以平板单极子天线为例,验证了该方法的有效性.最后,利用该方法对金属立方体上的低剖面电小环天线特性进行了分析,得出的结论对设计复杂载体上低剖面天线或天线阵有一定的参考价值。     

独立分量分析在机械振动信号分离中的应用

针对机械运转时工作环境复杂,监控采集的信号多为混合信号的情况,研究了如何从混合信号中分离出相对应的各振动源信号.采用独立分量分析的分离方法,通过对极大似然估计的目标函数进行简化,基于无需选择学习率的快速不动点迭代的优化方法,选用可同时估计亚高斯和超高斯独立成分的非线性函数估计概率密度,推导出了该算法.最后,对工程中几种特殊情况下的混合信号进行仿真和实验室实测的分离试验.结果表明,算法简单易行,具有快速稳定收敛的性质.     

Impact Dynamics of Supercavitating Projectile with Fluid/Structure Interaction

As supercavitating projectiles move at high speed, the periodic impacts ("tail-slap") on the interior surface of the cavity generally occur due to disturbances. The interactions between the projectile and the water/cavity interface are the sources of structural vibrations, which affect the guidance of the vehicle and undermine the structural reliability. The Fluid/Structure Interaction calculation procedure of the tail-slaps of supercavitating projectile is established, and the dynamic behaviours of the projectile operating in tail-slap conditions with and without considering Fluid/Structure Interaction are obtained and compared. The responses of the projectile riding a reducing cavity are studied, and the effect of Fluid/Structure Interaction is also analyzed. The results show that the angular velocity of projectile increases as the body slowing down, and the amplitude of the elastic displacement response decreases at the beginning and increases when the cavity size is close to the diameter of the tail of projectile. The effect of Fluid/Structure Interaction reduces the amplitudes and frequencies of the impact loads and the vibration responses of the body, and when the speed is higher, the effect is more apparent.     

SOLIDIFICATION PROCESS OF α(Al)-Mg_2Ge PSEUDOBINARY EUTECTIC ALLOYS

ＳＯＬＩＤＩＦＩＣＡＴＩＯＮＰＲＯＣＥＳＳＯＦα（Ａｌ）Ｍｇ２ＧｅＰＳＥＵＤＯＢＩＮＡＲＹＥＵＴＥＣＴＩＣＡＬＬＯＹＳ①ＺｈａｏＳｈｅｎｇｘｕ,ＬｉＳｈｕｎｐｕ,ＺｈａｏＤｅｑｉａｎ,ＰａｎＭｉｎｇｘｉａｎｇａｎｄＣｈｅｎＸｉｃｈｅｎＩｎｓｔｉｔｕ...     

WATER-COOLING CRUCIBLE VACUUM INDUCTION MELTING OF γ-TiAl BASED ALLOYS

ＷＡＴＥＲＣＯＯＬＩＮＧＣＲＵＣＩＢＬＥＶＡＣＵＵＭＩＮＤＵＣＴＩＯＮＭＥＬＴＩＮＧＯＦγＴｉＡｌＢＡＳＥＤＡＬＬＯＹＳ①ＳｕＹａｎｑｉｎｇ,ＧｕｏＪｉｎｇｊｉｅ,ＤｉｎｇＨｏｎｇｓｈｅｎｇ,ＷａｎｇＴｏｎｇｍｉｎ,ＺｈｕＨａｎｌｉａｎｇ,Ｊｉａ...     

DEVELOPMENT OF MATERIAL USED FOR AVIATION APPARATUS AXLE JOURNALS

ＤＥＶＥＬＯＰＭＥＮＴＯＦＭＡＴＥＲＩＡＬＵＳＥＤＦＯＲＡＶＩＡＴＩＯＮＡＰＰＡＲＡＴＵＳＡＸＬＥＪＯＵＲＮＡＬＳ①ＷｕＥｎｘｉ,ＬｉＳｈｅｎ,ＱｉａｎＣｈｏｎｇｌｉａｎｇａｎｄＺｏｕＺｈｉｑｉａｎｇＳｔａｔｅＫｅｙＬａｂｏｒａｔｏｒｙｆｏｒＰｏｗｄ...     

DEVELOPMENT OF MoS_2-CONTAINING Ni-Cr BASED ALLOYS AND THEIR HIGH-TEMPERATURE TRIBOLOGICAL PROPERTIES

ＤＥＶＥＬＯＰＭＥＮＴＯＦＭｏＳ２ＣＯＮＴＡＩＮＩＮＧＮｉＣｒＢＡＳＥＤＡＬＬＯＹＳＡＮＤＴＨＥＩＲＨＩＧＨＴＥＭＰＥＲＡＴＵＲＥＴＲＩＢＯＬＯＧＩＣＡＬＰＲＯＰＥＲＴＩＥＳ①ＸｉｏｎｇＤａｎｇｓｈｅｎｇＣｏｌｅｇｅｏｆＭｅｃｈａｎｉｃａｌＥｌ...     

LOW CYCLE FATIGUE IN TITANIUM ALUMINIUM FORMED BY CENTRIFUGAL SPRAY DEPOSITION

ＬＯＷＣＹＣＬＥＦＡＴＩＧＵＥＩＮＴＩＴＡＮＩＵＭＡＬＵＭＩＮＩＵＭＦＯＲＭＥＤＢＹＣＥＮＴＲＩＦＵＧＡＬＳＰＲＡＹＤＥＰＯＳＩＴＩＯＮ①ＣｈｅｎＷｅｎｚｈｅ,ＺｈａｎｇＳａａｎｄＱｉａｎＫｕａｎｇｗｕＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓ,Ｆｕ...     

FORMABILITY OF INTERMEDIATE COMPOUNDS IN OXIDE SYSTEMS OF M_2O_3-M'_2O_3 TYPE

ＦＯＲＭＡＢＩＬＩＴＹＯＦＩＮＴＥＲＭＥＤＩＡＴＥＣＯＭＰＯＵＮＤＳＩＮＯＸＩＤＥＳＹＳＴＥＭＳＯＦＭ２Ｏ３Ｍ′２Ｏ３ＴＹＰＥ①ＷｕＺｈｕ,ＬｉＣｈｏｎｇｈｅ,ＤｅｎｇＨｏｎｇｍｅｉａｎｄＣｈｅｎＮｉａｎｙｉＳｈａｎｇｈａｉＩｎｓｔｉｔｕｔｅｏｆＭ...