Simulation of two-dimensional ISAR decoys on a moving platform

It is potentially useful to perform deception jamming using the digital image synthesizer （DIS） since it can form a two-dimensional （2D） decoy but suffers from multiple decoys ge- neration. Inspired by the intermittent sampling repeater jamming （ISRJ）, the generation of inverse synthetic aperture radar （ISAR） decoys is addressed, associated with the DIS and the ISRJ. Radar pulses are sampled intermittently and modulated by the scatter- ing model of a false target by mounting the jammer on a moving platform, and then the jamming signals are retransmitted to the radar and a train of decoys are induced after ISAR imaging. A scattering model of Yak-42 is adopted as the false-target mo- dulation model to verify the effectiveness of the jamming method based on the standard ISAR motion compensation and image for- mation procedure.

光唇鱼源无乳链球菌的分离鉴定及遗传特征

【目的】为查明浙江养殖光唇鱼大量死亡的病原,了解病原的遗传特征。【方法】本工作对患病光唇鱼进行病原分离,结合形态特征、生理生化特性和16S rRNA基因序列同源性,对分离菌株进行鉴定;采用人工回感试验确定其病原性,并对分离株的血清型、多位点序列分型(multilocus sequence typing,MLST)、毒力基因型和表面蛋白抗原基因型等遗传特征进行分析;此外,还测试了菌株的药敏特性。【结果】从患病光唇鱼体中分离得到优势菌株ACRO-0708,为革兰氏阳性球菌,不溶血,分子与生化鉴定为无乳链球菌(Streptococcus agalactiae);人工感染试验证实其对光唇鱼有较强的致病性,LD_(50)为6.47×10^(3)CFU/g,属于血清型Ⅰb和MLST型ST261,毒力基因型为sip+bibA+cfb+hylB+iagA+fbsA+fbsB+bac–bca–cylE–scpB–lmb–,不携带所检测的6种表面蛋白基因。药敏试验结果显示,对青霉素、氨苄西林等8种药物较敏感,对氯霉素、复方新诺明等7种药物耐药。【结论】引起浙江养殖光唇鱼死亡的病原菌为无乳链球菌,其分子特征与水产动物主要流行的无乳链球菌株具有显著差异,生产中可选用氨苄西林、氟苯尼考等药物进行防治。