The detection of hypersonic targets usually confronts range migration(RM)issue before coherent integration(CI).The traditional methods aiming at correcting RM to obtain CI mainly considers the narrow-band radar condit...The detection of hypersonic targets usually confronts range migration(RM)issue before coherent integration(CI).The traditional methods aiming at correcting RM to obtain CI mainly considers the narrow-band radar condition.However,with the increasing requirement of far-range detection,the time bandwidth product,which is corresponding to radar’s mean power,should be promoted in actual application.Thus,the echo signal generates the scale effect(SE)at large time bandwidth product situation,influencing the intra and inter pulse integration performance.To eliminate SE and correct RM,this paper proposes an effective algorithm,i.e.,scaled location rotation transform(ScLRT).The ScLRT can remove SE to obtain the matching pulse compression(PC)as well as correct RM to complete CI via the location rotation transform,being implemented by seeking the actual rotation angle.Compared to the traditional coherent detection algorithms,Sc LRT can address the SE problem to achieve better detection/estimation capabilities.At last,this paper gives several simulations to assess the viability of ScLRT.展开更多
Aiming at the scale problem in heat-transfer equipments, experimental investigation on antiscale and scale removalby ultrasonic cavitation is performed. By means of microscopic magnifying photography system, thesedime...Aiming at the scale problem in heat-transfer equipments, experimental investigation on antiscale and scale removalby ultrasonic cavitation is performed. By means of microscopic magnifying photography system, thesedimentary phenomenon can be observed. The experimental research reveals the influencing rule of acoustic intensity,cavitational distance, liquid temperature and solution concentration. The experimental results indicate thatliquid temperature has different effects on antiscale and scale removal. Different experimental liquids are used forantiscale and scale removal experiments. The results show that every liquid has a respective Cavitational activetemperature. When ultrasonic is used for antiscale, the smaller acoustic intensity is, the better effect is. But, whenultrasonic is used for scale removal, acoustic intensity has a reverse influence. In addition, biggish solution concentrationis propitious to antiscale for long-time running. Distance of test sample to ultrasonic transducer alsohas certain influence on antiscale and scale removal. The smaller the distance to ultrasonic transducer is, the bettereffects antiscale and scale removal have.展开更多
基金supported by the National Natural Science Foundation of China(62101099)the Chinese Postdoctoral Science Foundation(2021M690558,2022T150100,2018M633352,2019T120825)+3 种基金the Young Elite Scientist Sponsorship Program(YESS20200082)the Aeronautical Science Foundation of China(2022Z017080001)the Open Foundation of Science and Technology on Electronic Information Control Laboratorythe Natural Science Foundation of Sichuan Province(2023NSFSC1386)。
文摘The detection of hypersonic targets usually confronts range migration(RM)issue before coherent integration(CI).The traditional methods aiming at correcting RM to obtain CI mainly considers the narrow-band radar condition.However,with the increasing requirement of far-range detection,the time bandwidth product,which is corresponding to radar’s mean power,should be promoted in actual application.Thus,the echo signal generates the scale effect(SE)at large time bandwidth product situation,influencing the intra and inter pulse integration performance.To eliminate SE and correct RM,this paper proposes an effective algorithm,i.e.,scaled location rotation transform(ScLRT).The ScLRT can remove SE to obtain the matching pulse compression(PC)as well as correct RM to complete CI via the location rotation transform,being implemented by seeking the actual rotation angle.Compared to the traditional coherent detection algorithms,Sc LRT can address the SE problem to achieve better detection/estimation capabilities.At last,this paper gives several simulations to assess the viability of ScLRT.
基金supported by National High-Tech Research and Development Program of China (863 Program, Grant No. 2006AA05Z203)National Natural Science Foundation of China (Grant No. 50806078)
文摘Aiming at the scale problem in heat-transfer equipments, experimental investigation on antiscale and scale removalby ultrasonic cavitation is performed. By means of microscopic magnifying photography system, thesedimentary phenomenon can be observed. The experimental research reveals the influencing rule of acoustic intensity,cavitational distance, liquid temperature and solution concentration. The experimental results indicate thatliquid temperature has different effects on antiscale and scale removal. Different experimental liquids are used forantiscale and scale removal experiments. The results show that every liquid has a respective Cavitational activetemperature. When ultrasonic is used for antiscale, the smaller acoustic intensity is, the better effect is. But, whenultrasonic is used for scale removal, acoustic intensity has a reverse influence. In addition, biggish solution concentrationis propitious to antiscale for long-time running. Distance of test sample to ultrasonic transducer alsohas certain influence on antiscale and scale removal. The smaller the distance to ultrasonic transducer is, the bettereffects antiscale and scale removal have.
