A Primary Study On The Optimum Design For Acoustic Focusing Conical Lens

Based on the Helmholtz integral with the Kirchhoff approximation, the signal receiving model of acoustic lens and the acoustic scattering model of the target have been made, and stationary phase method is used to evaluate the scattering wave.

论文基于Helmholtz积分，利用Kirchhoff近似建立了声学镜头接收信号模型和目标散射声模型，并采用稳定相位法计算目标散射声。

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Results and Conclusions: Our simulations show that in order to improve the focal shape, the outer diameter of the annulus must be as large but the radius of acoustic lens must be as small as possible.

结果与结论：为了改善椭球焦域长短轴之比，环状外径应尽量取大，声透镜半径应尽量取小；

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The paper focuses on the immersion line-focusing ultrasonic transducer with cylinder curved acoustic lens used in intelligent pig, establishes a mathematical model of acoustic fields, calculates its acoustic field distribution and focal length.

论文针对智能猪用柱形曲面声透镜水浸式线聚焦探头，建立了其声场模型，并对其轴线声场和焦距进行了数值模拟。

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The most pivotal technique is focalizing technique in HIFU technique. At present, self-focused 、 ultrasound phased array 、 acoustic lens and so on are in common use.

HIFU技术中最为关键的技术是聚焦技术，目前所采用的聚焦方式主要有：自聚焦、超声相控阵列聚焦、声透镜聚焦等。

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It was shown that using polystyrene as wedge material, high polymer as transducer material and curved wedge as an acoustic lens was the key point of application effectiveness for phased array system.

为保证相控阵探头在主要特性上等效于普通斜探头，用聚苯乙烯作楔块材料，用高分子聚合物作换能器材料，并用曲面声透镜改善探头在管子轴向和周向的声束特性。

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The acoustic lens focus system has many strong points, such as: ease of operation, structure simple, diverse shape and cheap of sound material and widely applied in the clinical medicine.

声透镜聚焦系统由于其操作方便、结构简单、形状多样、折声材料便宜等方面的优点而在临床医学中被广泛应用。

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We give them a sense of humor because laughter leaven life.

我们要给予他们幽默感，因为笑声可以使生活更轻松。

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There is a sense of humor around every corner when you're driving in America.

当你驾车行驶在美国，你会发现每个角落都飘着一股幽默感。

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Don't you have a sense of humor?

你没有幽默感吗？

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Somebody's got a sense of humor.

有人蛮有幽默感的。

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B Americans have this expression: It's good to have a sense of humor about life.

美国人有这样一句话，对生活有幽默感还是好的。

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Mother Nature certainly seems to have had a sense of humor in designing them!

自然母亲别有用心的设计尽显其幽默品味！

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Apparently, our boy has a sense of humor.

显然我们要找的人很有幽默感

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A sense of humor, you understand?

幽默感你懂不懂？

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It looked like clouds and a sense of humor didn't mix.

这里看上去乌云密布，和幽默感格格不入。

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It's called having a sense of humor.

这叫幽默感

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If some people don't have a sense of humor, then it's their problem.

如果有人缺乏幽默感，那是他们的问题。

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Having a sense of humor is also important in helping creativity in a child.

具有幽默感对于开发孩子的创造力也非常重要。

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You've not got a sense of humor.

你真是一点幽默感都没有。

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But are people really capable of having a sense of humor about themselves?

但人们真的能够对于自己也充满幽默么？

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