摘要：航空发动机可调尾喷管喉部面积直接影响其气动性能,传统上使用内径千分尺测量喉部尺寸,存在效率低下、喷口密封片下垂影响测量精度等问题。因此,提出一种基于激光干涉的可调圆形尾喷管喉部面积标定方法,设计激光干涉光路内置的同轴式长度测量结构,采用压力传感器实时反馈实现推力自适应控制,利用喉部尺寸测量数据计算喉部多边形面积,基于最小二乘法建立喉部面积与发动机控制信号之间的关联模型,实现喉部面积快速标定。试验结果证明,研制系统的尺寸测量精度为41μm,建立面积标定模型的拟合优度为0.98147,具有操作简捷、快速的特点,满足航空发动机测试需求。

摘要：电容法在原油含水率在线测量领域有广泛应用,然而其测量精度容易受到温度与原油中水的矿化度影响。为量化温度与矿化度对原油含水率测量的影响,提高测量精度,设计了一套基于PCAP01芯片的原油含水率测量系统,通过多项式拟合获得了温度-电容与矿化度-电容的独立补偿模型,结合温度-矿化度-介电常数补偿函数,建立了带有电极保护套的电容法原油含水率测量温度-矿化度简化补偿模型,实现原油含水率测量在线补偿,使含水率测量系统在温度与矿化度同时影响下的测量误差从4.38%降低到0.1%以内,有效提高了原油含水率测量的准确度。

摘要：Light detection and ranging (LIDAR) based on time of flight (TOF) method is widely used in many fields related to distance measurement. LIDAR generally uses laser diode (LD) to emit the pulsed laser with high peak power and short duration to ensure a large distance measurement range and eye safety. To achieve this goal, we propose a pulsed LD drive method producing the drive current with high peak and narrow pulse width. We analyze the key issues and related theories of the drive current generation based on this method and design an LD driver. A model of drive current generation is established and the influence of operating frequency on drive current is discussed. The LD driver is simulated by software and verified by experiments. The working frequency of the driver changes from 20 kHz to 100 kHz and the charging voltage is set at 130 V. The current produced by this driver has a duration of 8.8 ns and a peak of about 35 A, and the peak output optical power of the LD exceeds 75 W.

摘要：In order to achieve high precision measurement of inductance in a wide frequency range,a method of inductance measurement based on double-excitation auto-balancing bridge is *** this method,the direct digital synthesizer(DDS)as signal generator is used as the bridge excitation source,and the bridge is automatically balanced by adjusting and measuring the voltage *** standard resistors,the system can achieve high precision measurement of four-terminal pair inductors in the frequency range of *** at the low efficiency of bridge balancing,an iterative balancing algorithm based on the steepest descent method is *** order to suppress the interference caused by the initial phase change and non-integer periodic sampling,the high-precision measurement of the complex impedance of inductance is realized based on the all-phase fast Fourier transform(apFFT).Finally,the corresponding measurement system is built and the inductance measurement experiment is carried *** experimental results show that the relative error of the system for inductance measurement can be as low as 0.009%,and the optimal relative measurement uncertainty of the system can reach 9.89×10^(-4)compared with 5×10^(-5)of commercial impedance analyzer.

摘要：The disguised covert detection method that imitates whale calls has received great attention in recent years because it can solve the traditional problem of the trade-off between long-range detection and covert ***,under strong reverberation conditions,traditional echo signal processing methods based on matched filtering will be greatly *** on this,a disguised sonar signal waveform design is proposed based on imitating whale calls and computationally efficient anti-reverberation echo signal processing ***,this article proposed a disguised sonar signal waveform design method based on imitating whale *** method uses linear frequency modulation(LFM)signals to replace LFM-like segments in real whale calls,and extracts the envelope of the real whale call’s LFM-like segment to modify the LFM ***,this article proposed an echo signal processing method of fractional Fourier transform(FrFT)based on target echo locating of synchronization *** method uses the synchronization signal to locate the target echo,and determines the step-size interval of the FrFT based on the information carried by the synchronization *** with the traditional FrFT,this method effectively reduces the amount of calculation and also improves the anti-reverberation ***,the excellent performance of the proposed method is verified by simulation results.

摘要：当无线电通信受到干扰或要求无线电静默时,在森林作战的武装队伍之间将无法进行命令和情报传递。因此,亟需一种可以代替无线电通信的通信方式用于传输重要信息。针对这一需求,提出了一种新型的隐蔽声通信方法,该方法通过模仿动物的叫声来编码通信信息,并以绣眼鸟的叫声为例,利用绣眼鸟的叫声音节和音节之间的时间间隔来编码通信信息。为了减少译码计算量并提高编码效率,设计了一种基于时频特征的音节分组方法。同时,采用多种策略使得编码后的通信脉冲序列与真实铜蓝鹟叫声尽可能相似,以提高隐蔽性能,并通过实验验证在距离不超过60 m时,通信误码率不超过2%。最后,介绍了该通信方法的模型,并分析了在实际应用中可能遇到的问题,以及解决方案和未来的发展方向。研究结果表明,本方法可实现无线电不可用情况下的信息隐蔽传递。

摘要：随着对新时代高校学生思想政治要求的不断提高以及信息化技术的不断发展,传统的以教师为主体的灌输式教学模式将逐渐被混合式教学模式所替代。混合教学模式下专业课程融入课程思政元素,对促进专业教育与思政教育协同发展具有重要的意义。混合式教学模式下高校物流管理专业课课程思政的实施,应从混合式教学模式的设计、基于课程思政的教学目标的确定、教学内容的设计、教学质量评价体系的构建等多方面进行教学改革,从而达到教学创新与思政育人的双重目标,实现立德树人的根本任务。