查询词典 echo

The motion dynamics and echo models of the precessing warhead in single frequency are set up. Based on a quantitative analysis on echo spectrum and micro-Doppler modulation of precessing cone, a precession parameter estimation method by echo correlation and spectrum width is proposed. The experiments on data by simulation and darkroom measurement verify the method.

建立了单频信号下雷达观测弹头的进动模型和回波模型，通过对进动弹头回波频谱与微多普勒调制特性的定量分析，提出了利用回波相关方法和频谱展宽估计进动参数的方法，并利用暗室测量数据对该方法的性能进行了实验验证。

Careful analysis on NBE can facilitate nowcasting of severe weather events and further understanding of their evolution. After detailed study on three cases concerning with NBE, it is concluded:(1) NBE triggered by fast moving echo in upstream is an important indication of disastrous wind;(2) NBE can develop into severe storm under proper conditions. There are often two stages during this kind of growing: the first is developing of initial echo, the second is snap growing of echo core;(3) Doppler radar reflects outflow of downburst as a nearly ringed NBE. Inside look on downburst can be obtained combining NBE with other data.

文章结合发生在上海的3次强对流天气个例，详细分析了弱窄带回波在分析和预报强对流天气中的作用，得出以下结论：（1）上游移动强回波的出流边界导致的弱窄带回波是大风预警的重要判断参考；（2）在合适的层结状态和抬升条件下，弱窄带回波会强烈发展，并导致局地雷雨大风，这类强对流天气的发展有两个比较重要的阶段：弱窄带回波上初始回波的发展和回波跃增；（3）下击暴流造成的地面出流在雷达回波上表现为近似圆弧的弱窄带回波，这种弱窄带回波与其他雷达观测特征以及地面观测相结合，有助于对产生下击暴流的对流云的发生发展过程进行细致分析。

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。

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。

The hapless nymph, however, cannot even claim credit for echoes because the Greek word ekho, the source of English echo, existed with our common noun sense before any mention of Echo is found.

可惜的是这位不幸的女神并不能因为制造了回声这个词而居功，因为希腊语ekho ，即英语中echo 的来源，早在任何关于伊可的故事之前就存在了。

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。

Fostering the concept of multi-culture firmly and mastering the development of advanced culture correctly are conductive to resisting terrorism, separatism of nationalities and ultraism of religion, which is of great academic theoretical, immediate and profound historical si...

牢固树立多元文化的理念和正确把握先进文化的发展方向，有助于在世界范围内自觉地抵制恐怖主义，民族分裂主义和宗教极端主义。不仅具有重大的学术理论意义，而且也具有重大的现实意义和深远的历史意义。

But if anyone walks in the night, he stumbles, because the light is not in him.

11：10 若在黑夜行走，就必碰跌，因为那光不在他里面。