查询词典 echo-location

But, in the natural and artificial signal, a lot of signal phases don\'tvary linearly with time, for example, we usually use chirp signal in the radar technology,frequency step signal, linear modulation component of the ground echo in the SARtechnology, linear modulation component of the moving target echo, linear modulationcomponent while the airborn radar detecting the moving target, etc.

在自然界和人工信号中，许多信号的相位变化并不是随时间一次方变化，如雷达技术中常用的线性调频信号，频率步进信号，另外，SAR 技术中，地面回波所含有的线性调频分量，ISAR技术中，运动目标的回波所含有的线性调频分量，机载雷达探测运动目标时的线性调频分量，等等；傅里叶变换对此类信号分析所得的结果是信号在不同频率点上的能量分布，即信号在基函数上的投影。

In ultrasonic inspection of butt weld s, interfering echoes, such as corner echo, hill-shaped echo, etc.

在对接焊缝超声波探伤中，荧屏上常会出现一些影响缺陷判别的干扰回波，如焊角回波、"山形回波"等。

He went up to the mountains and shouted,"I hate you, I hate you,"and back came the echo"I hate you, I hate you."This was the first time that he had heard an echo.

他爬到山上大声喊："我恨你，我恨你"，就听见回声"我恨你，我恨你"，这是他第一次听到回声。

Echo chamber refers to a person who totally, obsequiously agrees with everything another person says, just like an echo chamber that is used to produce echoing sounds, usually for recording purposes.

这里的"回声筒"指的是某人为了献媚而完全同意另一个人所说的一切，就像录音时用来制造回声效果的回声筒一样。

Results There was no obvious change in the ulstrasonographic characteristics and the pathology of the control group.The diameters,internal echo,the continuity of internal linear echo and epineurium changed correpondingly with time of compression in different model groups.

结果声像图表现：对照组与卡压前正常神经未见明显改变，各卡压组高频超声下均可观察到相应声像图变化，随卡压时间的延长，卡压两端内径逐渐增粗，内部回声逐渐减低，内部线性回声连续性差，神经外膜逐渐增厚。

Back a car radar uses principle of ultrasonic range finding commonly, below the control of controller, transmit ultrasonic signal by sensor, when encountering fraise, generate echo signal, controller of the classics after sensor receives echo signal undertakes data processing, judgement gives the seat of fraise, by show

倒车雷达一般采用超声波测距原理，在控制器的控制下，由传感器发射超声波信号，当碰到障碍物时，产生回波信号，传感器接收到回波信号后经控制器进行数据处理、判定出障碍物的位置，由显

Using the time-gain compensation technique to compensate for ultrasonic wave's weaking when transmitting in the air,and reduce the fluctuation of echo signal.The peak time detecting circuit which is composed of full-wave rectification circuit and differential circuit can detect the reach time of echo signal accurately.

和其他方法相比，如激光测距、微波测距等，由于声波在空气中传播速度远远小于光线和无线电波的传播速度，对于时间测量精度的要求远小于激光测距、微波测距等系统，因而超声波测距系统电路易实现、结构简单和造价低，且超声波在传播过程中不受烟雾、空气能见度等因素的影响，在各种场合均得到广泛应用。

According to the difference of Doppler spectra of meteor trail echo and clutter of ground and sea,a FIR high-pass filter is designed to filter out clutter and so the meteor trail echo becomes obvious.

该文根据地海杂波与流星干扰在多普勒谱上的差别，提出了用FIR型高通滤波器滤除杂波使流星干扰凸显出来；再根据流星干扰的分布特点分段计算背景噪声均值，求取流星干扰检测门限；最后用杂波信号来插值流星干扰位置上的数据，消除因去除干扰造成的杂波相位不连续。

This method first jitters chirp rate polarity of LFM signal transmitted by the radar in slow-time domain,then does match-filters for the jamming signals hidden in the radar echoes,since jamming is more powerful than radar echo,the next process of limiting will lower the amplitude of jamming greatly,after limiting process,limited echoes are inversely match-filtered,so jamming and real radar echo are all back to the original time domain,then the next normal imaging process can be implemented which will also provide the real radar echo more gain than jamming,so SJR(Signal-to-Jamming Ratio) is further enhanced.

该方法首先在慢时间域捷变雷达发射信号的调频斜率极性，其次在接收脉冲后首先对转发的干扰信号进行匹配、限幅，然后在逆滤波之后正常成像。

Improved echo canceller for double-talk detection ;2. It is pointed out that the false detection results in the echo cancellation system to be unstable when traditional double-talk detection methods are applied in the echo cancellation.

首先讨论了回声消除中的双端发声问题，指出传统的双端发声检测方法用于回声消除时，其不可避免的误检会导致回声消除系统性能严重恶化，使系统不稳定。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。