In the OSNR model for EDFA amplifiers, SNR OUT = 1／(1／SNR IN ＋ FhvB／P IN ), what does SNR IN represent?() A. the signal to noise of the current optical amplifierB. the signal to noise of the previous amplifier or sourceC. the signal to noise introduced by the optical multiplexerD. the accumulated noise to signal ratio of the optical channel
In the OSNR model for EDFA amplifiers, SNR OUT = 1／(1／SNR IN ＋ FhvB／P IN ), what does SNR IN represent?()
A. the signal to noise of the current optical amplifier
B. the signal to noise of the previous amplifier or source
C. the signal to noise introduced by the optical multiplexer
D. the accumulated noise to signal ratio of the optical channel
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受试者操作特性曲线是A.NEQ.DQEB.MTFC.RMS.WSD.ROCE.SNR起初用于评价天体物理摄影系统成像质量的物理量的是A.NEQ.DQEB.MTFC.RMS.WSD.ROCE.SNR描述X线照片斑点特征的物理量是A.NEQ.DQEB.MTFC.RMS.WSD.ROCE.SNR描述成像系统分辨率特性的重要参量是A.NEQ.DQEB.MTFC.RMS.WSD.ROCE.SNR信噪比是A.NEQ.DQEB.MTFC.RMS.WSD.ROCE.SNR请帮忙给出每个问题的正确答案和分析，谢谢！
In the OSNR model for EDFA amplifiers, SNR OUT = 1/(1/SNR IN + FhvB/P IN ), what does SNR IN represent?（）A、the signal to noise of the current optical amplifierB、the signal to noise of the previous amplifier or sourceC、the signal to noise introduced by the optical multiplexerD、the accumulated noise to signal ratio of the optical channel
单选题In the OSNR model for EDFA amplifiers， SNR OUT = 1/（1/SNR IN + FhvB/P IN ）， what does SNR IN represent？（）A the signal to noise of the current optical amplifierB the signal to noise of the previous amplifier or sourceC the signal to noise introduced by the optical multiplexerD the accumulated noise to signal ratio of the optical channel
多选题关于MRI被检组织特性对SNR的影响，正确的是（ ）。A被检组织的质子密度低能产生较低的信号，SNR高B被检组织的质子密度高能产生较高的信号，SNR高C具有短T1的组织在T1WI上信号较高，SNR高D具有长T2的组织在T2WI上信号较低，SNR较低E具有长T2的组织在T2WI上信号较高，SNR高
多选题关于射频线圈与SNR的关系，正确的是（ ）。A体线圈SNR最低B体线圈包含的组织体积大，产生的信号量也大，SNR高C成像组织与线圈之间的距离越大，信号强度越大D线圈距离检查部位近，能最大程度地接收MR信号E表面线圈SNR最高
多选题下述说法正确的是（ ）。A短TR时，纵向磁化矢量增加，信号强度也增加B长TR时，信号强度增加，SNR高CTE越长，回波幅度越小，产生的信号量越少，SNR降低DTE越短，回波幅度越大，产生的信号量越多，SNR高ETE越长，回波幅度越大，产生的信号量越多，SNR高
单选题采用非均匀量化可以使得（ ）。A小信号量化SNR减小、大信号量化SNR增加B小信号量化SNR增加、大信号量化SNR减小C小信号量化SNR减小、人信号最化SNR减小D小信号量化SNR增加、大信号量化SNR增加
单选题What does a Cisco Unified Wireless IP Phone 7921G deployment require（）？Amore access points than a data networkBfewer access points than a data networkCless SNR than a data networkDspecific relative access point placement
单选题关于信噪比的描述，错误的是（ ）。A在一定范围内，SNR越高越好BSNR高的图像清晰，轮廓鲜明C当运动伪影被抑制后，MRI系统场强越高，产生的SNR越高D质子密度高的组织，SNR低E体素越大，SNR越高
单选题In the OSNR model for EDFA amplifiers, SNR OUT = 1/(1/SNR IN + FhvB/P IN ), what does SNR IN represent?（）Athe signal to noise of the current optical amplifierBthe signal to noise of the previous amplifier or sourceCthe signal to noise introduced by the optical multiplexerDthe accumulated noise to signal ratio of the optical channel
单选题关于射频线圈影响SNR的描述，错误的是（ ）。A射频线圈的类型影响SNR，尽量选择合适的表面线圈以提高SNRB检查部位与线圈间的距离越大，SNR越低C表面线圈距离检查部位近，能最大限度地接收MRI信号，所以其SNR高D线圈的形状、大小、敏感性均能影响SNRE体线圈的SNR最低，因为它包含的组织体积大，产生的噪声量小