Research on Earthquake Acceleration Alarm of Nuclear Power Plant

Almost all nuclear power plants in the world are equipped with seismic instrument system, especially the third generation nuclear power plants in China. When the ground motion measured by four time history accelerometers of containment foundation exceeds the preset threshold, the automatic shutdown trigger signal will be generated. However, from the seismic acceleration characteristics, isolated and prominent single high frequency will be generated the acceleration peak, which has no decisive effect on the seismic response, may cause false alarm, which has a certain impact on the smooth operation of nuclear power plant. According to the principle of three elements of ground motion, this paper puts forward a method that first selects the filtering frequency band which accords with the structural characteristics of nuclear power plants, then synthesizes the three axial acceleration time history, and finally selects the appropriate acceleration peak value for threshold alarm. The results show that the seismic acceleration results obtained by this method can well represent the actual magnitude of acceleration, and can solve the problem of false alarm due to the randomness of single seismic wave, and can be used for automatic reactor shutdown trigger signal of seismic acceleration.

Consideration of Trigger Mechanisms of Natural and Man-made Disasters in the Earth’s Geospheres

Have been presented the trigger mechanisms of accidents emergence in different Earth's Geospheres. Has been given the definition for the trigger mechanism of initiation of changes in geosystems. The threshold value for the starting (initiating) trigger signal has been detailed. The graphic representation of work of a trigger system has been presented, and its functioning has been explained. Various ways for switching of a trigger system have been revealed. The principles of the trigger impact on the troposphere, the lower part of the Earth's atmosphere, initiation of cyclones and earthquakes, and descent of avalanches and glacial mudflows have been detailed.

Dynamic Range Processing and Its Influence on Perceived Timing in Electronic Dance Music

In this article, we explore the extent to which dynamic range processing (such as compression and sidechain compression) influences our perception of a sound signal’s temporal placement in music. Because compression reshapes the sound signal’s envelope, scholars have previously noted that certain uses of sidechain compression can produce peculiar rhythmic effects. In this article, we have tried to interrogate and complicate this notion by linking a description of the workings and effects of dynamic range processing to empirical findings on the interaction between sound and perceived timing, and by analyzing multitracks and DAW project files, as well as released audio files, of selected EDM tracks. The analyses of the different EDM tracks demonstrated that sidechain compression affects the music in many possible ways, depending on the settings of the compressors’ parameters, as well as the rhythmic pattern and the sonic complexity of both the trigger signal and the sidechained signal. Dynamic range processing’s impact on groove and perceived timing indicates, in line with previous findings, that sound and timing interact in fundamental ways. Because of this interaction, then, we cannot limit ourselves to technical terms that describe how particular effects are achieved if we want to fully understand the grooves that are characteristic of EDM or other music. We must also consider how listeners experience these effects.

Ultrashort baseline synchronous-clock emergency resynchronizing method in the Jiaolong deep-sea manned submersible

During the dive operation of the Jiaolong deep-sea manned submersible, the synchronization clock in the manned cabin may be falsely triggered and cause asynchrony between it and the synchronization clock installed in the mothership, rendering it impossible for the ultrashort baseline to provide the correct position of the Jiaolong deep-sea manned submersible. To solve this problem, this article proposes an emergency resynchronizing method for the two synchronous clocks, used by the ultrashort baseline, in the Jiaolong deep-sea manned submersible. Initially, based on the depth and horizontal range measured by the ultrashort baseline and the manned submersible depth transmitted by the acoustic communication system, the time-delay difference between the two synchronous clocks is estimated. The time-delay difference is then compensated by delaying the synchronous clock trigger signal by an external waveform generator in the mothership. Finally, by comparing the depth measured by the ultrashort baseline and the manned submersible depth transmitted by the acoustic communication system, the time-delay difference is finely adjusted. Using this method, the ultrashort baseline problem, which occurred suddenly while the Jiaolong deep-sea manned submersible was diving, is successfully solved.