排序方式: 共有34条查询结果,搜索用时 15 毫秒
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A. Farina A. ProtopapaRadar Dpt Selenia S. p. A. Via Tiburtina Km. - Rome Italy 《系统工程与电子技术(英文版)》1992,(3)
After a brief recall of the Sidelobe Canceler (SLC) working principle, including the derivation of a general formula for the Cancellation Ratio (CR), the effects of channel mismatching are investigated. In particular, curves providing CRvalues as a function of amplitude and phase channel mismatching, radar bandwidth, and jammer direction of arrival (JDOA) are provided for the cases of one and two auxiliary antennas. Subsequently, a time -space processor for performance restoration is analyzed in detail. In addition to the above mentioned quantities, the attainable CR value is expressed as a function of the space-time processor parameters. The contribution of the paper is related to the derivation of a number of mathematical equations of CR for several cases of practical interest for the radar engineer. In addition, several curves are presented to assist design of SLC systems. 相似文献
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Tschöp M Castañeda TR Joost HG Thöne-Reineke C Ortmann S Klaus S Hagan MM Chandler PC Oswald KD Benoit SC Seeley RJ Kinzig KP Moran TH Beck-sickinger AG Koglin N Rodgers RJ Blundell JE Ishii Y Beattie AH Holch P Allison DB Raun K Madsen K Wulff BS Stidsen CE Birringer M Kreuzer OJ Schindler M Arndt K Rudolf K Mark M Deng XY Whitcomb DC Halem H Taylor J Dong J Datta R Culler M Craney S Flora D Smiley D Heiman ML Withcomb DC 《Nature》2004,430(6996):1 p following 165; discussion 2 p following 165
Batterham et al. report that the gut peptide hormone PYY3-36 decreases food intake and body-weight gain in rodents, a discovery that has been heralded as potentially offering a new therapy for obesity. However, we have been unable to replicate their results. Although the reasons for this discrepancy remain undetermined, an effective anti-obesity drug ultimately must produce its effects across a range of situations. The fact that the findings of Batterham et al. cannot easily be replicated calls into question the potential value of an anti-obesity approach that is based on administration of PYY3-36. 相似文献
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添加剂对AN多变晶型影响研究 总被引:1,自引:0,他引:1
本文运用热分析的方法对四十余种无机、有机添加剂和几种表面活性剂及水分对硝酸铵(AN)晶型转变的影响进行了研究。结果表明这些添加剂对AN的影响应为多种因素的综合结果。 相似文献
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文献[1]介绍了高分辨力雷达在改善目标检测中的潜在优点,强调了根据期望的目标径向距离分布图来形成发射波形和接收处理器的概念,并给出了性能预测。为克服先验信息的不足,本文提出并评估了一个自适应方案,用它来联机估算目标距离分布图。此外,引入了一个更一般性的、基于统计描述的目标冲击响应模型,讨论了相应的处理方案和检测性能。 相似文献
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J. Štěpán H. -J. Graubaum W. Meurer C. Wagenknecht 《Cellular and molecular life sciences : CMLS》1976,32(7):832-834
Summary In 260 normal students, 20–25 years old, the variation in the activities of serum alkaline phosphatase and its isoenzymes with sex, ABO blood groups, and protein intake were studied. The values are on the whole higher in males than in females. The activity of the intestinal isoenzyme was higher in subjects taking protein-rich diet than in those taking protein poor diet. 相似文献
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K. Ryšánek C. Švehla H. Špánková M. Mlejnková 《Cellular and molecular life sciences : CMLS》1966,22(5):320-321
Zusammenfassung Anti-Depressiva vom Imipramin-Typ, die die Aufnahme der biogenen Amine blockieren, hemmen auch gleichzeitig die durch Adrenalin bewirkte Thrombozyten-Aggregation. Dieser Befund unterstützt die Theorie des Mechanismus der Thrombozyten-Aggregation durch Adrenalin: Adrenalin dringt in die Zellen ein und setzt ATP aus den Thrombozyten frei, das sofort in ADP — den eigentlichen Aggregationsfaktor — umgewandelt wird. 相似文献
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K. Ryšánek C. švehla H. špánková M. Mlejnková 《Cellular and molecular life sciences : CMLS》1969,25(1):31-32
Zusammenfassung Myokinase, welche die Umwandlung von 2 Molekülen ADP in je 1 Molekül AMP und ATP katalysiert, hemmt die durch ADP sowie durch Adrenalin hervorgerufene Thrombozytenaggregation beträchtlich. Myokinase unterstützt die Desaggregation der durch Adrenalin aggregierten Thrombozyten. Diese Befunde weisen darauf hin, dass die makroergen Phosphate nicht nur für die Aggregation, sondern auch für die Desaggregation eine bedeutende Rolle spielen. 相似文献
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Lópéz-Sáez J. F. Giménez-Martín G. González-Fernández A. 《Cellular and molecular life sciences : CMLS》1966,22(8):501-502
Resumen En los meristemos radicales (en columna) las células hermanas poseen ciclos mitóticos de distinta duration según su positión con respecto al ápice. La célula hermana mâs próxima al ápice posee un ciclo ligeramente más corto que la otra. Se sugiere la existencia de un gradiente de la duration del ciclo desde las células iniciales hasta las células de la región de diferenciación. 相似文献