问题
问答题 简答题
什么叫自由空间，自由空间传播损耗如何定义？
答案
参考答案：
自由空间：无任何衰减、无任何阻挡、无任何多径的传播空间。无线电波在自由空间传播时，其单位面积中的能量会因为扩散而减少。这种减少称为自由空间传播损耗。自由空间传播损耗LS=32.44+20lgf（MHz）+20lgd（km）dB
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什么叫自由空间，自由空间传播损耗如何定义？
参考答案：
自由空间：无任何衰减、无任何阻挡、无任何多径的传播空间。无线电波在自由空间传播时，其单位面积中的能量会因为扩散而减少。这种减少称为自由空间传播损耗。自由空间传播损耗LS=32.44+20lgf（MHz）+20lgd（km）dB
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| "My name's Jim Shelley and I'm an addict (有瘾的人)…" With these words I began to 1 the problem, the problem of my telephone addiction. I used to call people 2 , from the moment I woke up to the time I went to sleep. I 3 to be phoned, I wanted to phone. Just one more call. It started socially-a few calls each day. It seemed 4 , just a quick chat. Gradually though, the 5 got worse. Soon it was 6 use, until, finally, addiction. And it began to affect(影响) my 7 . During the day I would disappear for 8 call. If I couldn't make a call, I spent the whole time waiting for the phone to ring. Getting more and more 9 , in the end, I would ring someone, then someone else, 10 myself just one more call. I was phoning people and 11 messages to make sure 12 calls would see me through the day. I used to arrive at friends' homes and before the door was closed, go straight for the phone with the 13 "Is it OK if I just use the phone…?" At work, I became 14 when my fellow workers tried to 15 me from using the phone. And one day I hit my boss (with the phone). Finally, the police caught me 16 a phone box that had taken my last one pound coin, and I was 17 to see a psychiatrist(心理医生). I haven't 19 a phone in the house for three weeks now, and it's several days 18 I used a phone box. I try not to watch TV because there are 20 people on it making phone calls. My name is Jim Shelley and I am an addict. | ||||
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