doppler effect

简明释义

多普勒效应

英英释义

例句

1.When a train speeds past, the change in pitch of its whistle is a clear example of the doppler effect (多普勒效应).

当火车快速经过时，其鸣笛音调的变化是doppler effect (多普勒效应)的一个明显例子。

2.In medical imaging, the doppler effect (多普勒效应) is used to measure blood flow in patients.

在医学成像中，doppler effect (多普勒效应)用于测量患者的血流。

3.Astronomers use the doppler effect (多普勒效应) to determine if a star is moving towards or away from Earth.

天文学家利用doppler effect (多普勒效应)来判断一颗星星是朝向地球还是远离地球移动。

4.The sound of the ambulance siren changes as it approaches and then passes by, demonstrating the doppler effect (多普勒效应).

救护车的警报声在接近和经过时变化，展示了doppler effect (多普勒效应)。

5.The doppler effect (多普勒效应) can also be observed with light waves, such as when a galaxy moves away from us.

当一个星系远离我们时，也可以观察到光波的doppler effect (多普勒效应)。

作文

The Doppler effect is a fascinating phenomenon that occurs when there is a relative motion between a source of waves and an observer. This effect can be observed in various types of waves, including sound waves and electromagnetic waves, such as light. The Doppler effect was first described by the Austrian physicist Christian Doppler in 1842, and it has since become a fundamental concept in physics and engineering.To understand the Doppler effect, consider a simple example involving sound waves. Imagine a police siren approaching you while you are standing on the sidewalk. As the police car gets closer, the sound waves compress, resulting in a higher pitch or frequency of the siren. This is because the sound waves are being emitted from the moving source (the police car) and are reaching your ears more frequently than they would if the car were stationary. Conversely, as the police car moves away from you, the sound waves stretch out, leading to a lower pitch. This shift in frequency is what we refer to as the Doppler effect.The Doppler effect is not limited to sound; it also applies to light. When an object emitting light moves towards an observer, the light waves are compressed, causing the light to shift towards the blue end of the spectrum. This is known as blue shift. On the other hand, if the light source is moving away from the observer, the waves are stretched, resulting in a red shift. This principle is crucial in astronomy, where scientists use the Doppler effect to determine the movement of stars and galaxies. By analyzing the light from distant celestial bodies, astronomers can infer whether these objects are moving closer to or farther away from Earth.The practical applications of the Doppler effect are vast and varied. In medicine, for instance, ultrasound technology utilizes the Doppler effect to measure blood flow in the body. By emitting sound waves into the body and analyzing the frequency changes as these waves bounce off moving blood cells, doctors can assess cardiovascular health and detect potential issues.In addition to its medical applications, the Doppler effect plays a significant role in radar and satellite technology. Weather radar systems use the Doppler effect to measure the speed and direction of precipitation, helping meteorologists predict storms and weather patterns accurately. Similarly, in the field of navigation, the Doppler effect is employed in GPS technology to enhance positioning accuracy.Furthermore, the Doppler effect has implications in everyday life. For example, when you hear a train whistle as it approaches and then passes you, you experience the Doppler effect firsthand. This phenomenon serves as a reminder of the dynamic nature of our world, where motion and sound interact in ways that can be both surprising and enlightening.In conclusion, the Doppler effect is a remarkable phenomenon that illustrates the relationship between motion and wave behavior. Its applications span across various fields, from medicine to astronomy and beyond. Understanding the Doppler effect not only deepens our comprehension of physics but also enhances our ability to utilize this knowledge in practical ways. As we continue to explore the universe and develop new technologies, the principles behind the Doppler effect will undoubtedly remain at the forefront of scientific inquiry and innovation.

多普勒效应是一个迷人的现象，当波源与观察者之间存在相对运动时，就会发生这种现象。这个效应可以在各种类型的波中观察到，包括声波和电磁波，如光波。多普勒效应最早由奥地利物理学家克里斯蒂安·多普勒于1842年描述，此后它已成为物理学和工程学中的基本概念。要理解多普勒效应，可以考虑一个简单的例子，涉及声波。想象一下，当你站在人行道上时，一辆警车的警报声向你驶来。当警车靠近时，声波被压缩，导致警报声的音调或频率升高。这是因为声波是从移动的源（警车）发出的，并且比如果汽车静止时更频繁地到达你的耳朵。相反，当警车远离你时，声波被拉伸，导致音调降低。这种频率的变化就是我们所称的多普勒效应。多普勒效应不仅限于声音；它也适用于光。当发光物体朝着观察者移动时，光波被压缩，导致光向光谱的蓝色端偏移。这被称为蓝移。另一方面，如果光源远离观察者，波被拉伸，导致红移。这个原理在天文学中至关重要，科学家利用多普勒效应来确定恒星和星系的运动。通过分析来自遥远天体的光，天文学家可以推断这些物体是靠近还是远离地球。多普勒效应的实际应用广泛而多样。例如，在医学中，超声技术利用多普勒效应来测量体内的血流。通过向体内发射声波并分析这些波在碰撞移动的血细胞时的频率变化，医生可以评估心血管健康状况并检测潜在问题。除了医学应用外，多普勒效应在雷达和卫星技术中也发挥着重要作用。气象雷达系统利用多普勒效应来测量降水的速度和方向，帮助气象学家准确预测风暴和天气模式。同样，在导航领域，多普勒效应被应用于GPS技术，以提高定位精度。此外，多普勒效应在日常生活中也有影响。例如，当你听到火车的鸣笛声，当它接近然后经过你时，你亲身体验了多普勒效应。这个现象提醒我们，我们的世界是动态的，运动和声音以惊人而启发的方式相互作用。总之，多普勒效应是一个显著的现象，说明了运动与波行为之间的关系。它的应用跨越多个领域，从医学到天文学及其他领域。理解多普勒效应不仅加深了我们对物理学的理解，还增强了我们以实际方式利用这一知识的能力。随着我们继续探索宇宙并开发新技术，多普勒效应背后的原理无疑将继续处于科学探究和创新的前沿。