The regression equation is A = 0. 2056c -8. 027 × 10-3, the correlative coefficient is r = 0. 9994,the linear range is 0.01 -2.44 mg/L, the recovery is 96% - 105% and RSD is 0. 2% - 1.5% . Calaulating at three times of the signal noise ratio, the detection limit of nickel is 7. 5 × 10-3 mg/L.

Methods Wrist joints in 20 normal volunteers were examined by T1WI,T2WI,T1W/SPIR,T2W/SPIR,and enhanced T1W/SPIR to measure and to compare the signal noise ratio(SNR)from each MR sequence. Then the statistic tests for the SNR data were performed.

A monofrequency lock-in amplifier for Auger Electon Spectroscopy has been designed and developed with operation frequency of 6299 Hz, sensitivity=1μV_(FS), minimum detectable signal noise ratio (S/N) = 1/50. The principal technical problems have been discussed in this article.

In order to improve the signal noise ratio and the precision of the analysis,a"two-level sifting"is processed in recording and analyzing VLP by HOLTER.

When the excitation frequency is 50KHz, the sensitivity, the STD (standard deviation) of the measured phase, the SNR (signal noise ratio) and the response time of the system are 11.46V/rad, 1.42*10-4rad, 41.842dB and 3s respectively.

The DEKORP data suffer from a low signal/noise ratio, so that special methods for the suppression of coherent noise trains were developed.

The application of better techniques using surface coils led to marked improvement of the signal noise ratio and measurement times in animal experiments could be reduced to minutes.

We extend the geometric model and the algorithm to 3D in order to extract shapes from low signal/noise ratio ultrasound image volumes.

The magnitude of the polarizer field and its inhomogeneity exhibit an optimum whose criteria are the signal/noise ratio in a system for registering the signal of nuclear magnetic resonance (NMR), the mass, and the overall dimensions of the device.

The potentialities of variation of the signal/noise ratio in pulsed NQR for spin I=1 with saturation of the quadrupole system at an adjacent transition are examined.

The lateral inhibitory network was studied as a spatial digital filter. When the distribution function of the inhibitory coefficient is Gaussian, the network isnotonly a filter which suppresses the lower spatial frequency components and thus enhancing the contrast, or a higher frequency pass filter, but it is also an inverse Gaussian filter which can recover the image blurred by the random disturbance in the medium, thus enhancing contrast and raising the 'signal-noise ratio'.The difference...

The lateral inhibitory network was studied as a spatial digital filter. When the distribution function of the inhibitory coefficient is Gaussian, the network isnotonly a filter which suppresses the lower spatial frequency components and thus enhancing the contrast, or a higher frequency pass filter, but it is also an inverse Gaussian filter which can recover the image blurred by the random disturbance in the medium, thus enhancing contrast and raising the 'signal-noise ratio'.The difference between the reourrent and nonrecurrent network has also been studied. When the distribution function of the lateral inhibition coefficient is Gaussian, the nonrecurrent inhibition network can not be an inverse Gaussion filter. In general, to possess the same given transfer function, fewer lateral branch interconnections and a simpler distribution of the lateral inhibition coefficient are needed for a recurrent network than for a nonrecurrent one, so that the recurrent inhibitory network can be constructed or regulated more easily.

The lateral inhibitory network was studied as a spatial digital filter. When the distribution function of the inhibitory coefficient is Gaussian, the network is not only a filter whioh suppresses the lower spatial frequency components and thus enhancing the contrast, or a higher frequency pass filter, but it is also an inverse Gaussian filter which can recover the image blurred by the random disturbance in the medium, thus enhancing contrast and raising the 'signal-noise ratio'.The difference...

The lateral inhibitory network was studied as a spatial digital filter. When the distribution function of the inhibitory coefficient is Gaussian, the network is not only a filter whioh suppresses the lower spatial frequency components and thus enhancing the contrast, or a higher frequency pass filter, but it is also an inverse Gaussian filter which can recover the image blurred by the random disturbance in the medium, thus enhancing contrast and raising the 'signal-noise ratio'.The difference between the recurrent and nonreourrent network has also been studied. When the distribution function of the lateral inhibition coefficient is Gaussian, the nonrecurrent inhibition network can not be an inverse Gaussion filter. In general, to possess the same given transfer function, fewer lateral branch interconnections and a simpler distribution of the lateral inhibition coefficient are needed for a recurrent network than for a nonrecurrent one, so that the recurrent inhibitory network can be constructed or regulated more easily.

A digital phase-locked loop is described in this paper. It is different from the convenient DPLL with its shorter time for synch-acquisition and longer time for holding synchronization. The time which is neccesary for synch-acquisition over a channel with a given signal noise ratio is discussed in detail. The dynamic response of the DPLL is obtained and the formula for calculating the time for holding synchronization is also derived in the paper. It is also emphasized that increasing the time for holding...

A digital phase-locked loop is described in this paper. It is different from the convenient DPLL with its shorter time for synch-acquisition and longer time for holding synchronization. The time which is neccesary for synch-acquisition over a channel with a given signal noise ratio is discussed in detail. The dynamic response of the DPLL is obtained and the formula for calculating the time for holding synchronization is also derived in the paper. It is also emphasized that increasing the time for holding synchronization of the described DPLL is possible with some improvement on stability of crystal voltage control oscillator. Finally some experimental results are briefly given.