The paper uses serial communication to control frequency scan of multi-receivers as soon as applying the feature of Win32 multithread and multiproc to make signal's real time collection and identification,which realizes the synchronization of serial communication and signal collection and identification.
It finds out the connection of the PSD of rail's vertical vibration speed and the wheel/rail surface roughness ratio spectrum depending on the Remington model and the coupling of wheel's radial vibration and rail's vertical vibration. By the method of admittance measure and frequency scan, we can obtain the character frequency of 60kg rail of China, first-order frequency is 150Hz and second-order frequency is 300Hz.
The results show that the three gluten proteins respectively exhibit the critical stresses of 49.59,24.88 and 12.48Pa during the stress sweep,the elastic moduli of 1194,789 and 583Pa during the frequency sweep with a sweeping frequency of 1.117rad/s,and the deformations of 7.09%,9.43% and 14.29% during the creep and recovery sweep with a sweeping period of 5.11min.
This paper elaborated the measuring system based on ISA bus interface, using the method of π network to measure the electrical parameters of quartz crystal wafer and direct digital synthesizer(DDS) to produce the wishing frequency scanning signal and stimulate π network We can get the resonate frequency,activity,clutter and so on;
This paper introduces a PLL frequency synthesizer BU2614 combined with a special radio module CAX1019S and a MCU AT89C51, which can realize the FM tuner. The tuner can realize multiple functions, such as automatic frequency scanning, locking, and displaying etc.
This paper mainly discusses the precise positioning method for the urban seismic mobile moving fault, and the study results shows: the frequency sweeping method and the mutual correlation method of data processing can effectively suppress the disturbances from strong vibrations with the vibroseis in the strong-disturbance background in the city so as to carry out the seismic investigations in the urban area;
The high resolution spectra are measured tuning the length of a CO2 waveguide laser by means of a PZT yielding a frequency scan of 230 MHz around the CO2 laser lines.
Our frequency scan data, as well as our data for the time course of resistance and capacitance, show that the fast change is associated with both the under-the-cells and between-the-cells resistance.
The high sensitivity of the intracavity arrangement allowed very strong double-resonance and two-photon transition signals to be observed with high microwave-frequency scan-rates (1 GHz/min), and low microwave pumping powers (≦10mW/cm2).
In this way an idler frequency scan of 100-150?GHz could be obtained, after which the signal frequency hops ahead over the FSR of the intracavity etalon of the OPO (207?GHz).
Low noise, mode-by-mode absorption spectra are recorded at a high acquisition rate (laser frequency scan greater than 400?GHz/s) and covering four orders of magnitude in absorption coefficient.