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51.
In recent years, considerable attention has been paid to adaptive clutter suppression for airborne early warning (AEW) radars.
A necessary condition for efficient clutter suppression is that the number of adaptive degrees of freedom (DOF) is no less
than that of clutter DOF. This paper analyzes the DOF of clutter for phased array AEW radars. The new results obtained here
are helpful to design and adaptive system for clutter suppression. 相似文献
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55.
相控阵机载雷达杂波抑制的时—空二维自适应滤波 总被引:22,自引:15,他引:22
本文提出了一种机载预警侧面相控阵雷达抑制地杂波的时-空二维自适应方法,该方法先对各列子阵的数据作多通道的多卜勒滤波,然后分别对相同多卜勒滤波器输出的数据作Capon自适应处理。理论分析和计算机模拟结果表明,本文方法的杂波抑制性能在天线阵元存在一定的随机幅度和相位误差情况下损失不大,对阵元失效也不敏感。 相似文献
56.
一种对象/关系映射框架的分析和应用 总被引:30,自引:0,他引:30
论文主要在分析面向对象系统中类及其实例与关系数据库中表的映射的基础上,引入了一种新的对象/关系映射框架:Hibernate.对Hibernate在对象/关系映射方面的优势、应用及其运行机制做了详细的分析. 相似文献
57.
为满足机载系统的需要,给出了共形相控阵天线的分析和设计过程,同时研制了一种高度仅为0.14波长的准八木天线单元。利用三维电磁仿真软件HFSS对天线单元和共形相控阵进行了仿真设计,并研制了一套L频段共形相控阵天线。该天线由天线阵面、波束形成网络和波控器等构成。天线阵面由4个天线单元组成,共形安装在机头上。经实际测试,共形相控阵天线阵面的和波束在扫描范围内增益大于10 dBi,并具有较低的副瓣电平;差波束零深小于-20 dB。 相似文献
58.
Shupeng Liu Ye Sun Heng Chen Suxian Song Yuhong Xu 《Applied biochemistry and biotechnology》2010,162(4):1206-1213
Salvianolic acid B is one of the effective components from the Chinese traditional drug Salvia miltiorrhiza (Danshen), which is widely used as a usual clinic drug for atherosclerosis-related disorder patients in China. But the targeting protein of salvianolic acid B is still not known. The possible targeting proteins of salvianolic acid B were explored by high throughput screening in this paper. Attached to the magnetic nanoparticles, salvianolic acid B was used for screening the high-affinity protein from the displaying cDNA peptide library phage. After biopanning, the selected protein or peptide sequences were used to explore the whole proteins containing the selected sequences in the National Center for Biotechnology Information website using blast. One of the selected phages was carried out by affinity analysis with salvianolic acid B using capillary electrophoresis (CE). The CE results indicated that the protein or peptide on the surface of the selected phages could bind the drug salvianolic acid B. The results are helpful to preliminarily explain the pharmacology of salvianolic acid B. 相似文献
59.
Rapeta V. V. V. J. RAO T. C. CHONG L. S. TAN W. S. LAU N. LIM 《International Journal of Electronics》2013,100(9):1039-1050
Low temperature (LT)-grown GaAs and Al0.3Ga0.7As metal-insulator-n+-GaAs (MIN) diodes have been fabricated and their electrical properties analyzed. Studies were carried out to evaluate the interfacial quality of the LT layer and the underlying n+-GaAs layer using transient current spectroscopy (TCS) and capacitance-frequency (C-f) characterization. TCS studies on LT-GaAs revealed a high concentration of a continuum of states anda dominant electron trap with an activation energy of 0.52eV. In LT-Al0.3Ga0.7As, a shallow trap at 0.36eV and two deep level traps at 0.85eV and 1.12eV were observed. Frequency dispersion was observed to be less for LT-GaAs samples with an AlAs barrier layer than without an AlAs barrier layer. However, LT-Al0.3Ga0.7As MIN diodes displayed a smaller frequency dispersion than LT-GaAs MIN diodes. Upon further investigation into MISFET devices, it was found that LT-Al0.3Ga0.7As MISFET devices had better transconductance frequency dispersion characteristics than LT-GaAs MISFET devices did. 相似文献
60.
Reactions of aldehydes with 2 equiv of alkyne in the presence of TiX(4) (X = Cl, Br) regioselectively generated 1,5-dihalo-1,4-dienes in moderate to good yields with high (E,Z)-stereoselectivity. [reaction: see text] 相似文献