{"id":418,"date":"2016-07-20T15:53:38","date_gmt":"2016-07-20T07:53:38","guid":{"rendered":"http:\/\/www.ntafyq.com\/?p=418"},"modified":"2016-07-27T12:27:52","modified_gmt":"2016-07-27T04:27:52","slug":"%e7%9f%a5%e8%af%86%ef%bc%9a%e8%b6%85%e5%a3%b0%e6%b3%a2%e7%9a%84%e5%ae%9a%e4%b9%89%e5%8f%8a%e7%89%a9%e7%90%86%e7%89%b9%e6%80%a7","status":"publish","type":"post","link":"http:\/\/www.ntafyq.com\/?p=418","title":{"rendered":"\u77e5\u8bc6\uff1a\u8d85\u58f0\u6ce2\u7684\u5b9a\u4e49\u53ca\u7269\u7406\u7279\u6027"},"content":{"rendered":"

\u8d85\u58f0\u6ce2\u63a2\u4f24\u4eea<\/a>\u662f\u901a\u8fc7\u5bf9\u8d85\u58f0\u6ce2\u53d7\u5f71\u54cd\u7a0b\u5ea6\u548c\u72b6\u51b5\u7684\u63a2\u6d4b\u4e86\u89e3\u6750\u6599\u6027\u80fd\u548c\u7ed3\u6784\u53d8\u5316\u7684\u6280\u672f\u79f0\u4e3a\u8d85\u58f0\u68c0\u6d4b<\/a>\u3002\u90a3\u4e48\u8d85\u58f0\u6ce2\u662f\u4e2a\u5565\u4e1c\u897f\u5462\uff1f\u8d85\u58f0\u6ce2<\/a>(Ultrasound)\u662f\u6307\u9891\u7387\u8d85\u8fc72\u4e07\u8d6b\u5179(Hertz,Hz)\u5373\u8d85\u8fc7\u4eba\u8033\u542c\u9608\u9ad8\u9650\u7684\u58f0\u6ce2,\u5c5e\u4e8e\u673a\u68b0\u6ce2\u3002<\/p>\n

\u4e00\u3001\u8d85\u58f0\u6ce2\u57fa\u672c\u7269\u7406\u91cf<\/strong><\/p>\n

\uff08\u4e00\uff09\u8d85\u58f0\u6ce2\u6709\u4e09\u4e2a\u57fa\u672c\u7269\u7406\u91cf\uff0c\u5373\u9891\u7387\uff08f\uff09\uff0c\u6ce2\u957f\uff08\u03bb\uff09\uff0c\u58f0\u901f\uff08c\uff09\u3002\u9891\u7387\uff08Frequency\uff09\u5c31\u662f\u5728\u6bcf\u79d2\u949f\u5185\uff0c\u4ecb\u8d28\u6240\u632f\u52a8\u7684\u6b21\u6570\uff0c\u4ee5f\u8868\u793a\uff0c\u5355\u4f4d\u4e3a\u8d6b\uff08Hz\uff09\uff1b\u58f0\u901f\uff08Speed of sound\uff09 \u6307\u58f0\u6ce2\u5728\u4f20\u64ad\u4ecb\u8d28\u4e2d\u7684\u4f20\u64ad\u901f\u5ea6\uff0c\u7528c\u8868\u793a\uff1b\u6ce2\u957f\uff08Wavelength\u4e3a\u5b8c\u6210\u4e00\u6b21\u5b8c\u5168\u632f\u52a8\u7684\u65f6\u95f4\u5185\u6240\u4f20\u64ad\u7684\u8ddd\u79bb\uff0c\u4ee5\u03bb\u8868\u793a\u3002\u4e09\u8005\u7684\u5173\u7cfb\u662f\uff1ac=f\u00b7\u03bb\u6216\u03bb=c\/f\uff0c\u4f20\u64ad\u8d85\u58f0\u6ce2\u7684\u5a92\u4ecb\u7269\u8d28\u53eb\u505a\u4ecb\u8d28\u3002<\/p>\n

\uff08\u4e8c\uff09\u76f8\u540c\u9891\u7387\u7684\u8d85\u58f0\u6ce2\u5728\u4e0d\u540c\u4ecb\u8d28\u4e2d\u4f20\u64ad\uff0c\u58f0\u901f\u4e0d\u76f8\u540c\u3002<\/p>\n

\uff08\u4e09\uff09\u58f0\u963b\u6297\uff08Acoustic impedance\uff09\u3000\u662f\u7528\u6765\u8868\u793a\u4ecb\u8d28\u4f20\u64ad\u8d85\u58f0\u6ce2\u80fd\u529b\u7684\u4e00\u4e2a\u91cd\u8981\u7684\u7269\u7406\u91cf\uff0c\u5176\u6570\u503c\u7684\u5927\u5c0f\u7531\u4ecb\u8d28\u5bc6\u5ea6\u03c1\u4e0e\u58f0\u6ce2\u5728\u8be5\u4ecb\u8d28\u4e2d\u7684\u4f20\u64ad\u901f\u5ea6C\u7684\u4e58\u79ef\u6240\u51b3\u5b9a\uff0c\u5373\uff1a Z=\u03c1\u00b7C \uff0c\u5355\u4f4d\u4e3aKg\uff0fm2\u00b7s\u3002<\/p>\n

\u4e8c\u3001\u8d85\u58f0\u6ce2\u7684\u7269\u7406\u6027\u80fd<\/strong><\/p>\n

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\uff08\u4e8c\uff09\u5f53\u5206\u754c\u9762\u4e24\u8fb9\u7684\u58f0\u901f\u4e0d\u540c\u65f6\uff0c\u8d85\u58f0\u6ce2\u900f\u5165\u7b2c\u4e8c\u79cd\u4ecb\u8d28\u540e\uff0c\u5176\u4f20\u64ad\u65b9\u5411\u5c06\u53d1\u751f\u6539\u53d8\u5373\u4ea7\u751f\u6298\u5c04\uff08Refraction\uff09\u3002\u58f0\u6ce2\u4ece\u4e00\u79cd\u5c0f\u58f0\u901f\u4ecb\u8d28\u5411\u5927\u58f0\u901f\u4ecb\u8d28\u5165\u5c04\u65f6\uff0c\u58f0\u6ce2\u7ecf\u8fc7\u8fd9\u4e24\u79cd\u4ecb\u8d28\u7684\u754c\u9762\u540e\u51fa\u73b0\u6298\u5c04\u6ce2\u7684\u6298\u5c04\u89d2\u5927\u4e8e\u5165\u5c04\u89d2\u3002\u5f53\u5165\u5c04\u89d2\u8d85\u8fc7\u4e34\u754c\u89d2\uff0890\u00b0\uff09\u65f6\uff0c\u76f8\u5e94\u7684\u6298\u5c04\u6ce2\u6d88\u5931\uff0c\u51fa\u73b0\u5168\u53cd\u5c04\u3002\u6211\u4eec\u5728\u8fdb\u884c\u8d85\u58f0\u68c0\u67e5\u65f6\uff0c\u9700\u8981\u5c3d\u53ef\u80fd\u5730\u5c06\u58f0\u675f\u5782\u76f4\u4e8e\u754c\u9762\uff0c\u907f\u514d\u5165\u5c04\u89d2\u8fc7\u5927\uff0c\u5426\u5219\u5c06\u4f1a\u5f15\u8d77\u53cd\u5c04\u4f53\u7684\u5b9e\u9645\u4f4d\u7f6e\u4e0e\u663e\u793a\u4f4d\u7f6e\u53d1\u751f\u9519\u4f4d\uff0c\u751a\u81f3\u51fa\u73b0\u5168\u53cd\u5c04\uff0c\u4ece\u800c\u5bfc\u81f4\u8d85\u58f0\u65e0\u6cd5\u68c0\u67e5\u8be5\u754c\u9762\u4ee5\u4e0b\u7684\u7ec4\u7ec7\u5668\u5b98\u3002<\/p>\n

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\uff08\u56db\uff09\u8d85\u58f0\u6ce2\u5728\u4f20\u64ad\u4e2d\u9047\u5230\u7c97\u7cd9\u9762\u6216\u6781\u5c0f\u7684\u969c\u788d\u7269\uff08\u6216\u4e00\u7ec4\u5c0f\u969c\u788d\u7269\u5f62\u5f0f\uff09\u65f6\uff0c\u5c06\u6709\u4e00\u90e8\u5206\u80fd\u91cf\u88ab\u6563\u5c04\uff08Scattering\uff09<\/p>\n

\uff08\u4e94\uff09\u8d85\u58f0\u6ce2\u5728\u4ecb\u8d28\u5185\u7684\u4f20\u64ad\u8fc7\u7a0b\u4e2d\uff0c\u968f\u7740\u4f20\u64ad\u8ddd\u79bb\u7684\u589e\u5927\uff0c\u58f0\u6ce2\u7684\u80fd\u91cf\u9010\u6e10\u51cf\u5c11\uff0c\u8fd9\u4e00\u73b0\u8c61\u79f0\u4e3a\u58f0\u6ce2\u8870\u51cf\uff08Acoustic attenuation\uff09\u3002\u58f0\u6ce2\u8870\u51cf\u4e0e\u4ecb\u8d28\u5bf9\u58f0\u6ce2\u7684\u5438\u6536(Acoustic absorption)\u3001\u6563\u5c04\u4ee5\u53ca\u58f0\u675f\u6269\u6563\u7b49\u539f\u56e0\u6709\u5173\uff0c\u5176\u4e2d\u5438\u6536\u662f\u8870\u51cf\u7684\u4e3b\u8981\u56e0\u7d20\u3002<\/p>\n

\uff08\u516d\uff09\u591a\u666e\u52d2\u6548\u5e94\uff08Doppler effect\uff09 \u4e3a\u58f0\u6e90\u4e0e\u63a5\u6536\u5668\u4e4b\u95f4\u7684\u76f8\u5bf9\u8fd0\u52a8\u800c\u5bfc\u81f4\u58f0\u6ce2\u9891\u7387\u53d1\u751f\u6539\u53d8\u7684\u73b0\u8c61\u3002\u5f53\u58f0\u6e90\u4e0e\u63a5\u6536\u5668\u4f5c\u76f8\u5411\u8fd0\u52a8\u65f6\uff0c\u63a5\u6536\u5668\u6240\u63a5\u6536\u5230\u7684\u58f0\u6ce2\u9891\u7387\u9ad8\u4e8e\u58f0\u6e90\u6240\u53d1\u51fa\u7684\u9891\u7387\uff0c\u5982\u4e24\u8005\u7684\u8fd0\u52a8\u65b9\u5411\u76f8\u53cd\u65f6\uff0c\u5219\u63a5\u6536\u9891\u7387\u4f4e\u4e8e\u58f0\u6e90\u6240\u53d1\u51fa\u7684\u9891\u7387\uff0c\u4e24\u8005\u7684\u9891\u7387\u5dee\u4e3a\u9891\u79fb\uff08Frequency shift\uff09\u3002\u8d85\u58f0\u591a\u666e\u52d2\u4eea\u5668\u7684\u8d85\u58f0\u6e90\u548c\u63a5\u6536\u5668\u5747\u5b89\u88c5\u5728\u63a2\u5934\uff08\u6362\u80fd\u5668\uff09\u4e2d\uff0c\u63a2\u5934\u5de5\u4f5c\u65f6\uff0c\u6362\u80fd\u5668\u53d1\u51fa\u8d85\u58f0\u6ce2\uff0c\u7531\u8fd0\u52a8\u7740\u7684\u7ea2\u7ec6\u80de\u53d1\u51fa\u6563\u5c04\u56de\u6ce2\uff0c\u518d\u7531\u63a5\u6536\u6362\u80fd\u5668\u63a5\u6536\u6b64\u56de\u6ce2\u3002\u56e0\u6b64\u63a5\u6536\u6362\u80fd\u5668\u6240\u6536\u5230\u7684\u8d85\u58f0\u56de\u6ce2\u7684\u9891\u7387\u7ecf\u8fc7\u4e86\u4e24\u6b21\u591a\u666e\u52d2\u6548\u5e94\u8fc7\u7a0b\uff0c\u6240\u4ee5\u6536\u53d1\u8d85\u58f0\u9891\u7387\u4e4b\u5dee\u4e0e\u8840\u6d41\u76f8\u5bf9\u4e8e\u6362\u80fd\u5668\u8fd0\u52a8\u901f\u5ea6\u7684\u4e24\u500d\u6210\u6b63\u6bd4<\/p>\n","protected":false},"excerpt":{"rendered":"

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