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A Study on the Counter Measures for Eco-friendly Land Use Model in Mountainous Area——a Case of Qianjiang District of Chongqing Municipality 被引量:8
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作者 谭伟 张安明 An-ming 《Agricultural Science & Technology》 CAS 2010年第5期182-186,共5页
Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pione... Accompanying the development of social economy,the land use model of mountainous area,typically eco-weak area,is changing gradually. Here the establishment of eco-friendly land use model in mountainous area,will pioneer the model of sustainable development in that area. Concerning Qianjiang District of Chongqing Municipality,huge change of land use model,mainly embodied in the unceasing increase of construction land and gradual decrease of agricultural use land,has taken place in recent years. To explore the eco-friendly land use model in mountainous area,Qianjiang District was chosen as the study object in the present study. Via analyzing the changes in land use model,we found that related eco-environment restrictive factors mainly regional climatic change,soil texture,hydrological environment as well as soil erosion and land degradation,etc. And based on these results,we further analyzed the effect of land use change on eco-environment and the factors restricting the maintenance of eco-environment and regional development,finally put forward the counter measures for balancing land use and co-environment in mountainous area. The results will be important for the development of social economy and eco-system construction in Qianjiang District. 展开更多
关键词 Mountainous area Eco-friendly Land use Qianjiang District
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Environmental Issues of Geothermal Development in Yangbajing, Tibet and the Countermeasures 被引量:4
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作者 LiHui-xia HeXiao-rong +1 位作者 HuXian-cai DuoJi 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03B期965-974,共10页
The pollution source and pollution state of surface water is respectively assessed with equal-standard-pollution-load index and Nemero index, and the habitans' health is assessed as well by comparison with pre-dev... The pollution source and pollution state of surface water is respectively assessed with equal-standard-pollution-load index and Nemero index, and the habitans' health is assessed as well by comparison with pre-development of geo-thermal field. Results show that: 1) Three pollutive factors obviously fail to attain the required standards and their order sorted by impact degree is As>F- >S2-. 2) The Nemero index of Donggua cross section of Duilongqu River is 0. 725 and the water quality is at mildly-polluted level. 3) In Lhasa River, the Nemero indexes of cross sections affected by geo-thermal fields are much higher than that of the unaffected one, which shows the present and potential impacts of geo-thermal development. 4) Much more inhabitants nearby got trichomadesis sickness after geothermal development, which shows that the surface water pollution in this area has threatened the inhabitants' health. In addition, other environmental issues caused by Yangbajing geothermal development are analyzed and some countermeasures are proposed. 展开更多
关键词 Yangbajing of Tibet geothermal energy resources equal-standard-pollution-load index Nemero index counter measures
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A "Declining" Power and Its Counter measures
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作者 Shi Yinhong is a Professor of the School of International Relations and Director of theCenter for American Studies, Remin University of China. 《Contemporary International Relations》 2004年第12期1-7,共7页
关键词 DECLINING Power and Its counter measures
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The Opening of China's Securities: Challenge, Opportunities and Counter Measures
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作者 Bao Daiqin Zhao Huaiyong 《China's Foreign Trade》 1999年第12期15-18,共4页
No matter what is the outcome,as long as China is linked with theworld economy and enjoys thebenefits brought about by variouscountries that have opened theirsecurities market, China’s securities market will open soo... No matter what is the outcome,as long as China is linked with theworld economy and enjoys thebenefits brought about by variouscountries that have opened theirsecurities market, China’s securities market will open sooner or later. 展开更多
关键词 CHALLENGE Opportunities and counter measures
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On China's Accession to the WTO: Many Entrepreneurs Are Optimistic, But Few Have Counter Measures
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作者 Yang Wei 《China's Foreign Trade》 2000年第3期39-39,共1页
关键词 On China’s Accession to the WTO view But Few Have counter measures Many Entrepreneurs Are Optimistic
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基于纯硬件电路的轴角-数字解码系统研究
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作者 王浩 牛伟 卢玉芳 《计算机技术与发展》 2024年第11期9-13,共5页
针对旋转变压器解码系统需要软硬件协同合作及系统结构复杂的问题,提出了一种基于纯硬件电路的轴角-数字解码系统,主要包括解调模块和解算模块。解调模块基于与激励信号同步的脉冲信号控制采样/保持电路来得到低频的解调信号;为避免使... 针对旋转变压器解码系统需要软硬件协同合作及系统结构复杂的问题,提出了一种基于纯硬件电路的轴角-数字解码系统,主要包括解调模块和解算模块。解调模块基于与激励信号同步的脉冲信号控制采样/保持电路来得到低频的解调信号;为避免使用AD转换、昂贵的压控振荡器等复杂硬件,解算模块采用了负反馈结构,主要基于计数器实现,通过正余弦LUT查找表将计数值转换为旋转变压器角度的线性输出,计数值表示解算角度;当解算角度与实际角度不一致时,解算模块会控制计数值增加或者减少,直到解算角度与实际角度一致。为验证该方法的有效性,在Matlab/Simulink中搭建系统模型进行多工况仿真验证,结果表明,纯硬件解码方法在角度阶跃变化、匀速变化及系统存在噪声时均能稳定正常工作,并且误差不超过0.2°,响应时间不超过2 ms,优于常规软件解码方法。最后进一步制作了验证板卡进行了实物验证,验证结果表明该系统具有较好的稳定性及精度。 展开更多
关键词 旋转变压器 轴角-数字变换 计数器 仿真 角度测量
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Measurements of non-equilibrium and equilibrium temperature behind a strong shock wave in simulated martian atmosphere 被引量:4
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作者 Xin Lin Xi-Long Yu +3 位作者 Fei Li Shao-Hua Zhang Jian-Guo Xin Xin-Yu Zhang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2012年第5期1296-1302,共7页
Non-equilibrium radiation measurements behind strong shock wave for simulated Martian atmosphere are presented in this paper. The shock wave is established in a hydrogen oxygen combustion driven shock tube. Time- reso... Non-equilibrium radiation measurements behind strong shock wave for simulated Martian atmosphere are presented in this paper. The shock wave is established in a hydrogen oxygen combustion driven shock tube. Time- resolved spectra of the Av = 0 sequence of the B^2∑^+ → X^2∑^+ electronic transition of CN have been observed through optical emission spectroscopy (OES). A new method, which is based on fitting high resolution spectrum for rotational and vibrational temperatures measurement, is proposed to diag- nose temperature distribution behind the shock wave. It is estimated that the current scheme has the maximum deviation less than 8% (lσ) for vibrational temperature measurement through detailed analysis of the influence of the uncertainties of spectroscopic constants and spectral resolution. Radiation structure of the shock layer, including induction, relaxation and equilibrium process, and corresponding rotational and vibrational temperatures are obtained through time gating OES diagnostics with sub-microsecond temporal resolution. The present extensive results will strongly benefit the reaction rate estimation and computational fluid dynamics (CFD) code validation in high enthalpy Mars reentry chemistry. 展开更多
关键词 Radiation measurements - Shock wave Marsre-entry Rotational temperature Vibrational temperature
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MIMO Channel Measurement and Characterization at 6.0-6.4 GHz Under Typical Classroom Environment 被引量:3
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作者 Ji-Liang Zhang Yang Wang +2 位作者 Li-Qin Ding Xiao-Min Huang Nai-Tong Zhang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2014年第1期69-76,共8页
An extensive 4 x 4 MIMO channel measurement is carried out at 6. 0-6. 4 GHz under a typical classroom environment with channel sounder based on vector network analyzer. Both LOS and NLOS scenarios are considered. The ... An extensive 4 x 4 MIMO channel measurement is carried out at 6. 0-6. 4 GHz under a typical classroom environment with channel sounder based on vector network analyzer. Both LOS and NLOS scenarios are considered. The results on path loss, delay spread and spatial correlation are presented. The measurement shows that, for corridor coverage, 2x2 MIMO is more economical than 4x4 MIMO due to high correlation. In order to identify the unique characteristics at the high frequency band, the measured channel parameters at 6. 0-6.4 GHz are compared with those at 2. 45 GHz. The comparison shows that the shortened wavelength of this higher frequency band results in a great difference of channel characteristics. Therefore, our measurement results provide new gnidance for the design and development of the system working on 6. 0-6.4 GHz band. 展开更多
关键词 6. 0-6.4 GHz muhi-input multi-output (MIMO) channel measurement channel characteristics
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Carrier fringe method of moire interferometry for tiny strain measurements in micro-field 被引量:2
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作者 Yudong Cao Shibin Wang +1 位作者 Shuangxi Qi Jingwei Tong 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第1期101-106,共6页
In this paper, we demonstrate a new optical method for tiny strain measurements based on the principle of carrier fringes of moire interferometry. A cross-line grating with frequency of 1200 lp/mm is replicated on the... In this paper, we demonstrate a new optical method for tiny strain measurements based on the principle of carrier fringes of moire interferometry. A cross-line grating with frequency of 1200 lp/mm is replicated on the specimen surface, and the strain can be deduced from the changes in carrier fringes before and after the deformation of an object. Four coherent laser beams are used to obtain the carrier fringe patterns of field U and V. Both theoretical analysis and numerical simulation indicate that the ideal accuracy of strain can be controlled within a range of ±1με. Case study of a plane extension experiment shows that the measurement accuracy of strain can be controlled within the range of ±10με. The average strain values of every row of field U and every column of field V can be obtained by using this method, and approximated strain of every pixel in the whole-field can be further acquired, and thus it is possible to measure tiny strains occurred in a micro-field. The technology in this paper can provide comprehensive information for analyzing related mechanical content in the field of MEMS. 展开更多
关键词 Moire interferometry - Carrier fringe Micro-field Tiny strain. measured accuracy
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Measurement and simulation of the two-phase velocity correlation in sudden-expansion gas-particle flows 被引量:3
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作者 Li-Xing Zhou.Yang Liu.Yi Xu Department of Engineering Mechanics,Tsinghua University,100084 Beijing,China Marine Engineering College,Dalian Maritime University,116026 Dalian,China 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2011年第4期494-501,共8页
In this paper the present authors measured the gas-particle two-phase velocity correlation in sudden expansion gas-particle flows with a phase Doppler particle anemometer (PDPA) and simulated the system behavior by ... In this paper the present authors measured the gas-particle two-phase velocity correlation in sudden expansion gas-particle flows with a phase Doppler particle anemometer (PDPA) and simulated the system behavior by using both a Reynolds-averaged Navier-Stokes (RANS) model and a large-eddy simulation (LES). The results of the measurements yield the axial and radial time-averaged velocities as well as the fluctuation velocities of gas and three particle-size groups (30μm, 50μm, and 95μm) and the gasparticle velocity correlation for 30μm and 50μm particles. From the measurements, theoretical analysis, and simulation, it is found that the two-phase velocity correlation of sudden-expansion flows, like that of jet flows, is less than the gas and particle Reynolds stresses. What distinguishes the two-phase velocity correlations of sudden-expansion flow from those of jet and channel flows is the absence of a clear relationship between the two-phase velocity correlation and particle size in sudden-expansion flows. The measurements, theoretical analysis, and numerical simulation all lead to the above-stated conclusions. Quantitatively, the results of the LES are better than those of the RANS model. 展开更多
关键词 PDPA measurement - Simulation Two-phasevelocity correlation Sudden expansion gas-particle flows
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Predicament and Countermeasure Analysis of Intellectual Property Management for Strategic Emerging Industry 被引量:2
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作者 Zhang Lingwei Liu Dunhu 《学术界》 CSSCI 北大核心 2014年第7期303-307,共5页
Intellectual property is the core support and important driving force for the sound development of strategic emerging industry. This paper makes an analysis on the current predicament of intellectual property manageme... Intellectual property is the core support and important driving force for the sound development of strategic emerging industry. This paper makes an analysis on the current predicament of intellectual property management for strategic emerging industry from the four stages of the process,including creation and development management,business management,revenue management and disposal management on intellectual property,and finally explores the solutions and gives some countermeasures. 展开更多
关键词 知识产权管理 新兴产业 业务管理 收入
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Auto-measuring System of 3-Dimensional Human Body
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作者 李勇 尚保平 +1 位作者 付小莉 尚会超 《Journal of Donghua University(English Edition)》 EI CAS 2001年第3期110-112,共3页
To realize the automation of fashion industry measuring,designing and manufacturing, the auto-measurement of 3D size of human body is of great importance. The auto measurement system of 3D human body based on Charge C... To realize the automation of fashion industry measuring,designing and manufacturing, the auto-measurement of 3D size of human body is of great importance. The auto measurement system of 3D human body based on Charge Coupled Devices (CCD) and infrared sensors is presented in this paper. The system can measure the bare size of human body that excludes the effect of clothing quickly and accurately. 展开更多
关键词 3- D measurement HUMAN BODY measurement.
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Analysis and counter measure in blood grouping errors of volunteers’donating blood
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《中国输血杂志》 CAS CSCD 2001年第S1期378-,共1页
关键词 Analysis and counter measure in blood grouping errors of volunteers
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3-Dimensional Body Measurement Technology
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作者 周旭东 李艳梅 《Journal of Donghua University(English Edition)》 EI CAS 2002年第4期138-140,共3页
3 - dimensional body measurement technology, the basis of developing high technology in industry, accelerates digital development of aplparel industry. This paper briefly introduces the history of 3 - dimensional body... 3 - dimensional body measurement technology, the basis of developing high technology in industry, accelerates digital development of aplparel industry. This paper briefly introduces the history of 3 - dimensional body measurement technology, and recounts the principle and primary structure of some types of 3 - dimensional automatic body measurement system. With this understanding, it discusses prospect of 3- dimensional CAD and virtual technology used in apparel industry. 展开更多
关键词 3 - DIMENSIONAL BODY measurement technology digital apparel industry quick response virtual fitting apparel NAD
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Fundamental Properties and Optimal Gains of a Steady-State Velocity Measured <i>α</i>-<i>β</i>Tracking Filter
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作者 Kenshi Saho 《Advances in Remote Sensing》 2014年第2期61-76,共16页
This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filt... This paper clarifies the steady-state properties and performance of an α-β filter for moving target tracking using both position and velocity measurements. We call this filter velocity measured α-β (VM-α-β) filter. We first derive the stability condition and steady-state predicted errors as fundamental properties of the VM-α-β filter. The optimal gains for representative motion models are then derived from the Kalman filter equations. Theoretical and numerical analyses verify that VM-α-β filters with these optimal gains realize more accurate tracking than conventional α-β filters when the filter gains are relatively large. Our study reveals the conditions under which the predicted errors of the VM-α-β filters are less than those of conventional α-β filters. Moreover, numerical simulations clarify that the variance of the tracking error of the VM-α-β filters is approximately 3/4 of that of the conventional α-β filters in realistic situations, even when the accuracy of the position/velocity measurements is the same. 展开更多
关键词 α-β FILTER Moving Target Tracking VELOCITY measurement KALMAN FILTER OPTIMAL Gain
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Test of Normality of Waist Measurement Data of Young Male and Female Adults based on the Quantile - Quantile Plot
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作者 F. Z. Okwonu J. N. Igabari 《Journal of Statistical Science and Application》 2017年第3期118-126,共9页
This paper investigates the normality of some real data set obtained from waist measurements of a group of 49 young adults. The quantile - quantile (Q-Q) plot and the analysis of correlation coefficients for the Q-Q... This paper investigates the normality of some real data set obtained from waist measurements of a group of 49 young adults. The quantile - quantile (Q-Q) plot and the analysis of correlation coefficients for the Q-Q plot is used to determine the normality or otherwise of the data set. In this regards, the probabilities of the quantiles were computed, modified and plotted. Thereafter the correlation coefficients for the quantile - quantile plots were obtained. Results indicate that at 0.1 level of significance, the data for young adult males of the sample were not normally distributed, and had a mean value that is within the range of low risk, healthwise, whereas the distribution of the data for young female adults showed reasonable normality, but also with a mean value that is within the range of low risk in terms of health condition. 展开更多
关键词 Correlation coefficient probability plot quantile - quantile plot test of normality waist measurement young adults.
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A Steady-State Errors Correction Method for Eliminating Measurement Errors
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作者 田新良 杨苹 《Journal of Donghua University(English Edition)》 EI CAS 2013年第4期298-304,共7页
This paper proposes a steady-state errors correction(SSEC)method for eliminating measurement errors.This method is based on the detections of error signal E(s)and output C(s)which generate an expected output R(s).In c... This paper proposes a steady-state errors correction(SSEC)method for eliminating measurement errors.This method is based on the detections of error signal E(s)and output C(s)which generate an expected output R(s).In comparison with the conventional solutions which are based on detecting the expected output R(s)and output C(s)to obtain error signal E(s),the measurement errors are eliminated even the error might be at a significant level.Moreover,it is possible that the individual debugging by regulating the coefficient K for every member of the multiple objectives achieves the optimization of the open loop gain.Therefore,this simple method can be applied to the weak coupling and multiple objectives system,which is usually controlled by complex controller.The principle of eliminating measurement errors is derived analytically,and the advantages comparing with the conventional solutions are depicted.Based on the SSEC method analysis,an application of this method for an active power filter(APF)is investigated and the effectiveness and viability of the scheme are demonstrated through the simulation and experimental verifications. 展开更多
关键词 measurement errors steady-state errors correction (SSEC) active power filters (APF)CLC number:TM77Document code:AArticle ID:1672-5220(2013)04-0298-07
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一种基于双重Counter Bloom Filter的长流识别算法 被引量:25
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作者 吴桦 龚俭 杨望 《软件学报》 EI CSCD 北大核心 2010年第5期1115-1126,共12页
提出了一种基于双层Counter Bloom Filter的长流识别算法(algorithm based on double counter bloom filter for long flows identification,简称CCBF).该算法使用两层Counter Bloom Filter结构,将长流过滤和长流存在分开处理.分析了该... 提出了一种基于双层Counter Bloom Filter的长流识别算法(algorithm based on double counter bloom filter for long flows identification,简称CCBF).该算法使用两层Counter Bloom Filter结构,将长流过滤和长流存在分开处理.分析了该算法的误判率,通过模拟数据分析了算法错误率和内存资源限制的关系,并在相同内存资源限制的条件下,将该算法与类似算法的准确性进行了比较.结果表明,在数据量较大的情况下,该算法具有比现有算法更小的平均错误率;对算法的时间效率分析表明,该算法可以达到1500kpps的处理速度.各项指标反映出,该算法可以应用于大规模主干网的长流监测. 展开更多
关键词 长流识别 双重 计数Bloom FILTER 网络测量 主干网
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用于D-D、D-T混合能量中子测量的长计数器研究 被引量:3
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作者 艾杰 代红跃 +4 位作者 文延伟 范锐锋 马景芳 刘小平 刘进 《核电子学与探测技术》 CAS CSCD 北大核心 2010年第11期1466-1468,共3页
对De Pangher长计数器的能量响应曲线进行了理论模拟。计算结果表明:在De Pangher长计数器前端增加一定厚度的聚乙烯慢化体,可使其对D-D、D-T中子的探测效率基本相同,从而实现D-D、D-T混合能量中子的测量。在加速器上对这种结构的长计... 对De Pangher长计数器的能量响应曲线进行了理论模拟。计算结果表明:在De Pangher长计数器前端增加一定厚度的聚乙烯慢化体,可使其对D-D、D-T中子的探测效率基本相同,从而实现D-D、D-T混合能量中子的测量。在加速器上对这种结构的长计数器进行了效率刻度,结果表明,当聚乙烯材料厚度约为9 cm时,长计数器对D-D、D-T中子的探测效率相等。 展开更多
关键词 混合中子 中子测量 长计数器
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用非相干光纤马-泽微波光子结构实现瞬时测频 被引量:3
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作者 王旭 胡总华 +2 位作者 冯志荣 王全辉 陈秀丽 《现代雷达》 CSCD 北大核心 2011年第11期37-39,共3页
在复杂的电磁环境下,传统的微波瞬时测频方法面临严峻的挑战,难以满足现代电子战的需要。近年来,利用微波光子学方法,能够克服电子学方法瞬时测频带宽窄的瓶颈,且系统体积小,抗干扰能力强。针对全频段频率测量,采用非相干光纤马-泽结构... 在复杂的电磁环境下,传统的微波瞬时测频方法面临严峻的挑战,难以满足现代电子战的需要。近年来,利用微波光子学方法,能够克服电子学方法瞬时测频带宽窄的瓶颈,且系统体积小,抗干扰能力强。针对全频段频率测量,采用非相干光纤马-泽结构,通过对光纤马-泽臂长差和两耦合器耦合系数的选取,得到了较好线性度和较大斜率的幅度比较函数曲线,实现了雷达微波信号0~40 GHz的全频段测量,仿真分析验证了该方法的可行性和有效性。 展开更多
关键词 瞬时测频 微波光子技术 电子对抗
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